mirror of
https://github.com/PX4/PX4-Autopilot.git
synced 2025-12-08 11:41:39 +08:00
Remove legacy translations
This commit is contained in:
Hamish Willee
@@ -1,457 +0,0 @@
|
||||
# Configuration/Tuning (Ackermann Rover)
|
||||
|
||||
This topic provides a step-by-step guide for setting up your [Ackermann rover](../frames_rover/ackermann.md).
|
||||
|
||||
Successive steps enable [drive modes](../flight_modes_rover/ackermann.md) with more autopilot support and features.
|
||||
|
||||
:::warning
|
||||
Each step is dependent on the previous steps having been completed.
|
||||
Modes will only work properly if the preceding modes have been configured.
|
||||
:::
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To configure the Ackermann rover frame and outputs:
|
||||
|
||||
1. Enable Rover support by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
Note that this is a special build that contains rover-specific modules.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select the _Generic Rover Ackermann_:
|
||||
|
||||
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe is not displayed and you have checked that you are using rover firmware (not the default), you can alternatively enable this frame by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `51000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Open the [Actuators Configuration & Testing](../config/actuators.md) to map the steering and throttle functions to flight controller outputs.
|
||||
|
||||
## 수동 모드
|
||||
|
||||
:::warning
|
||||
For this mode to work properly the [Basic Setup](#basic-setup) must've already been completed!
|
||||
:::
|
||||
|
||||
The basic setup already covers the minimum setup required to use the rover in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode).
|
||||
|
||||
This mode is also affected by (optional) acceleration/deceleration limits.
|
||||
As configuration of these limits becomes mandatory for subsequent modes, we do this setup here.
|
||||
|
||||
Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RA_WHEEL_BASE](#RA_WHEEL_BASE) [m]: Measure the distance from the back to the front wheels.
|
||||
|
||||
2. [RA_MAX_STR_ANG](#RA_MAX_STR_ANG) [deg]: Measure the maximum steering angle.
|
||||
|
||||
|
||||
|
||||
3. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: Drive the rover at full throttle and set this parameter to the observed value of the ground speed.
|
||||
|
||||
:::info
|
||||
This parameter is also used for the feed-forward term of the speed control.
|
||||
It will be further tuned in the configuration of [Position mode](#position-mode).
|
||||
|
||||
:::
|
||||
|
||||
4. (Optional) [RO_ACCEL_LIM](#RO_ACCEL_LIM) [m/s^2]: Maximum acceleration you want to allow for your rover.
|
||||
|
||||
<a id="RO_ACCEL_LIM_CONSIDERATIONS"></a>
|
||||
|
||||
:::tip
|
||||
Your rover has a maximum possible acceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. From a standstill, give the rover full throttle until it reaches the maximum speed.
|
||||
2. Disarm the rover and plot the `measured_speed_body_x` from [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md).
|
||||
3. Divide the maximum speed by the time it took to reach it and set this as the value for [RO_ACCEL_LIM](#RO_ACCEL_LIM).
|
||||
|
||||
Some RC rovers have enough torque to lift up if the maximum acceleration is not limited.
|
||||
If that is the case:
|
||||
|
||||
1. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to a low value, give the rover full throttle from a standstill and observe its behaviour.
|
||||
2. Increase [RO_ACCEL_LIM](#RO_ACCEL_LIM) until the rover starts to lift up during the acceleration.
|
||||
3. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
:::
|
||||
|
||||
5. (Optional) [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2]: Maximum deceleration you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
The same [considerations](#RO_ACCEL_LIM_CONSIDERATIONS) as in the configuration of [RO_ACCEL_LIM](#RO_ACCEL_LIM) apply.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
This parameter is also used for the calculation of the speed setpoint during [Auto modes](#auto-modes).
|
||||
|
||||
:::
|
||||
|
||||
6. (Optional) [RA_STR_RATE_LIM](#RA_STR_RATE_LIM) [deg/s]: Maximum steering rate you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
This value depends on your rover and use case.
|
||||
For bigger rovers there might be a mechanical limit that is easy to identify by steering the rover at a standstill and increasing
|
||||
[RA_STR_RATE_LIM](#RA_STR_RATE_LIM) until you observe the steering rate to no longer be limited by the parameter.
|
||||
For smaller rovers you might observe the steering to be too aggressive. Set [RA_STR_RATE_LIM](#RA_STR_RATE_LIM) to a low value and steer the rover at a standstill.
|
||||
Increase the parameter until you reach the maximum steering rate you are comfortable with.
|
||||
|
||||
:::
|
||||
|
||||
:::warning
|
||||
A low maximum steering rate makes the rover worse at tracking steering setpoints, which can lead to a poor performance in the subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
## Acro Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Manual mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
To set up [Acro mode](../flight_modes_rover/ackermann.md#acro-mode) configure the following [parameters](../advanced_config/parameters.md) in QGroundControl:
|
||||
|
||||
1. [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM): Maximum yaw rate you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
Limiting the yaw rate is necessary if the rover is prone rolling over, loosing traction at high speeds or if passenger comfort is important.
|
||||
Small rovers especially can be prone to rolling over when steering aggressively at high speeds.
|
||||
|
||||
If this is the case:
|
||||
|
||||
1. In [Acro mode](../flight_modes_rover/ackermann.md#acro-mode), set [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) to a small value and drive the rover at full throttle and with the right stick all the way to the left or right.
|
||||
2. Increase [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) until the wheels of the rover start to lift up.
|
||||
3. Set [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
If you see no need to limit the yaw rate, set this parameter to the maximum yaw rate the rover can achieve:
|
||||
|
||||
1. In [Manual mode](#manual-mode) drive the rover at full throttle and with the maximum steering angle.
|
||||
2. Plot the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and enter the highest observed value for [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM).
|
||||
|
||||
|
||||
:::
|
||||
|
||||
2. [RO_YAW_RATE_P](#RO_YAW_RATE_P) [-]: Proportional gain of the closed loop yaw rate controller.
|
||||
The closed loop acceleration control will compare the yaw rate setpoint with the measured yaw rate and adapt the motor commands based on the error between them.
|
||||
The proportional gain is multiplied with this error and that value is added to the motor command.
|
||||
This compensates for disturbances such as uneven ground and external forces.
|
||||
|
||||
:::tip
|
||||
To tune this parameter:
|
||||
|
||||
1. Put the rover in [Acro mode](../flight_modes_rover/ackermann.md#acro-mode) and hold the throttle stick and the right stick at a few different levels for a couple of seconds each.
|
||||
2. Disarm the rover and from the flight log plot the `adjusted_yaw_rate_setpoint` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
3. Increase [RO_YAW_RATE_P](#RO_YAW_RATE_P) if the measured value does not track the setpoint fast enough or decrease it if the measurement overshoots the setpoint by too much.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_YAW_RATE_I](#RO_YAW_RATE_I) [-]: Integral gain of the closed loop yaw rate controller.
|
||||
The integral gain accumulates the error between the desired and actual yaw rate scaled by the integral gain over time and that value is added to the motor command.
|
||||
|
||||
::: tip
|
||||
An integrator might not be necessary at this stage, but it will become important for subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Acro mode](../flight_modes_rover/ackermann.md#acro-mode).
|
||||
|
||||
## Stabilized Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Acro mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
For [Stabilized mode](../flight_modes_rover/differential.md#stabilized-mode) the controller utilizes a closed loop yaw controller, which creates a yaw rate setpoint to control the yaw when it is active:
|
||||
|
||||
|
||||
|
||||
Unlike the closed loop yaw rate, this controller has no feed-forward term.
|
||||
Therefore you only need to tune the closed loop gains:
|
||||
|
||||
1. [RO_YAW_P](#RO_YAW_P) [-]: Proportional gain for the closed loop yaw controller.
|
||||
|
||||
::: tip
|
||||
In stabilized mode the closed loop yaw control is only active when driving a straight line (no yaw rate input).
|
||||
To tune it start with a value of 1 for [RO_YAW_P](#RO_YAW_P).
|
||||
Put the rover into stabilized mode and move the left stick of your controller up to drive forwards.
|
||||
Disarm the rover and from the flight log plot the `measured_yaw` and the `adjusted_yaw_setpoint` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) message over each other.
|
||||
Increase/Decrease the parameter until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
For the closed loop yaw control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
Since the yaw and yaw rate controllers are cascaded, there only needs to be one integrator which is in the yaw rate controller. If you observe a steady state error in the yaw setpoint increase the [RO_YAW_RATE_I](#RO_YAW_RATE_I) parameter.
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Stabilized mode](../flight_modes_rover/ackermann.md#stabilized-mode).
|
||||
|
||||
## Position Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Stabilized mode](#stabilized-mode) must already be configured!
|
||||
:::
|
||||
|
||||
[Position mode](../flight_modes_rover/ackermann.md#position-mode) is the most advanced manual mode, utilizing closed loop yaw rate and speed control and leveraging position estimates.
|
||||
|
||||
To configure set the following parameters:
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM) [m/s]: This is the maximum speed you want to allow for your rover.
|
||||
This will define the stick-to-speed mapping for position mode and set an upper limit for the speed setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop speed control which linearly maps desired speeds to normalized motor commands.
|
||||
As mentioned in the [Manual mode](../flight_modes_rover/ackermann.md#manual-mode) configuration , a good starting point is the observed ground speed when the rover drives at maximum throttle in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode).
|
||||
|
||||
<a id="RA_SPEED_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter:
|
||||
|
||||
1. Set [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I) to zero.
|
||||
This way the speed is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and then move the left stick of your controller up and/or down and hold it at a few different levels for a couple of seconds each.
|
||||
3. Disarm the rover and from the flight log plot the `adjusted_speed_body_x_setpoint` and the `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
4. If the actual speed of the rover is higher than the speed setpoint, increase [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
::: info
|
||||
If your rover oscillates when driving a straight line in [Position mode](../flight_modes_rover/ackermann.md#position-mode), set this parameter to the observed ground speed at maximum throttle in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode) and complete steps 5-7 first before continuing the tuning of the closed loop speed control (Steps 2-4).
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_SPEED_P](#RO_SPEED_P) [-]: Proportional gain of the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RO_MAX_THR_SPEED](#RA_SPEED_TUNING).
|
||||
If you tuned [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_SPEED_I](#RO_SPEED_I) [-]: Integral gain for the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
For the closed loop speed control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
|
||||
:::
|
||||
|
||||
5. [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN): When driving in a straight line (right stick centered) position mode leverages the same path following algorithm used in [auto modes](#auto-modes) called [pure pursuit](#pure-pursuit-guidance-logic) to achieve the best possible straight line driving behaviour ([Illustration of control architecture](#pure_pursuit_controller)).
|
||||
This parameter determines how aggressive the controller will steer towards the path.
|
||||
|
||||
::: tip
|
||||
Decreasing the parameter makes it more aggressive but can lead to oscillations.
|
||||
|
||||
To tune this:
|
||||
|
||||
1. Start with a value of 1 for [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN)
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and while driving a straight line at approximately half the maximum speed observe its behaviour.
|
||||
3. If the rover does not drive in a straight line, reduce the value of the parameter, if it oscillates around the path increase the value.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
6. [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN): Minimum threshold for the lookahead distance used by the [pure pursuit algorithm](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and drive at very low speeds, if the rover starts to oscillate even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then increase the value of [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
:::
|
||||
|
||||
7. [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX): Maximum threshold for the lookahead distance used by [pure pursuit](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and drive at very high speeds, if the rover does not drive in a straight line even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then decrease the value of [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Position mode](../flight_modes_rover/ackermann.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
:::warning
|
||||
For auto modes to work properly [Manual Mode](#manual-mode), [Acro mode](#acro-mode)and [Position mode](#position-mode) must already be configured!
|
||||
:::
|
||||
|
||||
<a id="pure_pursuit_controller"></a>
|
||||
|
||||
In [auto modes](../flight_modes_rover/ackermann.md#auto-modes) the autopilot takes over navigation tasks using the following control architecture:
|
||||
|
||||
|
||||
|
||||
The required parameter configuration is discussed in the following sections.
|
||||
|
||||
### Speed
|
||||
|
||||
1. [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2] and [RO_JERK_LIM](#RO_JERK_LIM) [m/s^3] are used to calculate a speed trajectory such that the rover reaches the next waypoint with the correct [cornering speed](#cornering-speed).
|
||||
|
||||
::: tip
|
||||
Plan a mission for the rover to drive a square and observe how it slows down when approaching a waypoint:
|
||||
|
||||
- If the rover decelerates too quickly decrease the [RO_DECEL_LIM](#RO_DECEL_LIM) parameter, if it starts slowing down too early increase the parameter.
|
||||
- If you observe a jerking motion as the rover slows down, decrease the [RO_JERK_LIM](#RO_JERK_LIM) parameter otherwise increase it as much as possible as it can interfere with the tuning of [RO_DECEL_LIM](#RO_DECEL_LIM).
|
||||
|
||||
These two parameters have to be tuned as a pair, repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
2. Plot the `adjusted_speed_body_x_setpoint` and `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I).
|
||||
|
||||
### Corner Cutting
|
||||
|
||||
The module employs a special cornering logic causing the rover to "cut corners" to achieve a smooth trajectory.
|
||||
This is done by scaling the acceptance radius based on the corner the rover has to drive (for geometric explanation see [Cornering logic](#mission-cornering-logic-info-only)).
|
||||
|
||||
|
||||
|
||||
The degree to which corner cutting is allowed can be tuned, or disabled, with the following parameters:
|
||||
|
||||
:::info
|
||||
The corner cutting effect is a tradeoff between how close you get to the waypoint and the smoothness of the trajectory.
|
||||
:::
|
||||
|
||||
1. [NAV_ACC_RAD](#NAV_ACC_RAD) [m]: Default acceptance radius
|
||||
This is also used as a lower bound for the acceptance radius scaling.
|
||||
2. [RA_ACC_RAD_MAX](#RA_ACC_RAD_MAX) [m]: The maximum the acceptance radius can be scaled to.
|
||||
Set equal to [NAV_ACC_RAD](#NAV_ACC_RAD) to disable the corner cutting effect.
|
||||
3. [RA_ACC_RAD_GAIN](#RA_ACC_RAD_GAIN) [-]: This tuning parameter is a multiplicand on the [calculated ideal acceptance radius](#corner-cutting-logic) to account for dynamic effects.
|
||||
|
||||
:::tip
|
||||
Initially set this parameter to `1`.
|
||||
If you observe the rover overshooting the corner, increase this parameter until you are satisfied with the behaviour.
|
||||
Note that the scaling of the acceptance radius is limited by [RA_ACC_RAD_MAX](#RA_ACC_RAD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
### Path Following
|
||||
|
||||
The [pure pursuit](#pure-pursuit-guidance-logic) algorithm is used to calculate a yaw rate setpoint for the vehicle that is then close loop controlled.
|
||||
The close loop yaw rate was tuned in the configuration of the [Acro mode](#acro-mode), and the pure pursuit was tuned when setting up the [Position mode](#position-mode).
|
||||
During any auto navigation task observe the behaviour of the rover.
|
||||
|
||||
If you are unsatisfied with the path following, there are 2 steps to take:
|
||||
|
||||
1. Plot the `adjusted_yaw_rate_setpoint` and the `measured_yaw_rate` from the [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
2. Plot the `adjusted_yaw_setpoint` and the `measured_yaw` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the value for [RO_YAW_P](#RO_YAW_RATE_P) and potentially further tune [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
3. Steps 1 and 2 ensures accurate setpoint tracking, if the path following is still unsatisfactory you need to further tune the [pure pursuit](#pure-pursuit-guidance-logic) parameters.
|
||||
|
||||
## Pure Pursuit Guidance Logic
|
||||
|
||||
The desired yaw setpoints are generated using a pure pursuit algorithm.
|
||||
|
||||
The controller takes the intersection point between a circle around the vehicle and a line segment.
|
||||
In mission mode this line is usually constructed by connecting the previous and current waypoint.
|
||||
|
||||
|
||||
|
||||
The radius of the circle around the vehicle is used to tune the controller and is often referred to as look-ahead distance.
|
||||
|
||||
The look-ahead distance sets how aggressive the controller behaves and is defined as $l_d = v \cdot k$.
|
||||
It depends on the velocity $v$ of the rover and a tuning parameter $k$ that can be set with the parameter [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN).
|
||||
|
||||
:::info
|
||||
A lower value of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) makes the controller more aggressive but can lead to oscillations!
|
||||
:::
|
||||
|
||||
The lookahead is constrained between [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX) and [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
If the distance from the path to the rover is bigger than the lookahead distance, the rover will target the point on the path that is closest to the rover.
|
||||
|
||||
To summarize, the following parameters can be used to tune the controller:
|
||||
|
||||
| 매개변수 | 설명 | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | ---- |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius | m |
|
||||
|
||||
## Mission Cornering Logic (Info only)
|
||||
|
||||
### Corner Cutting Logic
|
||||
|
||||
To enable a smooth trajectory, the acceptance radius of waypoints is scaled based on the angle between a line segment from the current-to-previous and current-to-next waypoints.
|
||||
The ideal trajectory would be to arrive at the next line segment with the heading pointing towards the next waypoint.
|
||||
For this purpose the minimum turning circle of the rover is inscribed tangentially to both line segments.
|
||||
|
||||
|
||||
|
||||
The acceptance radius of the waypoint is set to the distance from the waypoint to the tangential points between the circle and the line segments:
|
||||
|
||||
$$
|
||||
\begin{align*}
|
||||
r_{min} &= \frac{L}{\sin\left( \delta_{max}\right) } \\
|
||||
\theta &= \frac{1}{2}\arccos\left( \frac{\vec{a}*\vec{b}}{|\vec{a}||\vec{b}|}\right) \\
|
||||
r_{acc} &= \frac{r_{min}}{\tan\left( \theta\right) }
|
||||
\end{align*}
|
||||
$$
|
||||
|
||||
| Symbol | 설명 | Unit |
|
||||
| ----------------------------------- | ---------------------------------- | ---- |
|
||||
| $\vec{a}$ | Vector from current to previous WP | m |
|
||||
| $\vec{b}$ | Vector from current to next WP | m |
|
||||
| $r_{min}$ | Minimum turn radius | m |
|
||||
| $\delta_{max}$ | Maximum steer angle | m |
|
||||
| $r_{acc}$ | Acceptance radius | m |
|
||||
|
||||
### Cornering Speed
|
||||
|
||||
To smoothen the trajectory further and reduce the risk of the rover rolling over, the rover speed is regulated as follows:
|
||||
|
||||
1. During cornering the rover drives at the following speed:
|
||||
|
||||
<!-- prettier-ignore -->
|
||||
|
||||
$$v_{cor, max} = \dot{\psi}_{max} \cdot r$$
|
||||
|
||||
with $r:$ Turning radius for the upcoming corner and $\dot{\psi}_{max}:$ Maximum yaw rate ([RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM)).
|
||||
|
||||
2. In between waypoints (straight line) the rover speed is regulated such that it will arrive at the acceptance radius of the waypoint with the desired cornering speed.
|
||||
|
||||
The rover is constrained between the maximum speed [RO_SPEED_LIM](#RO_SPEED_LIM) and the speed where the maximum steering angle does not cause the rover to exceed the yaw rate limit:
|
||||
|
||||
<!-- prettier-ignore -->
|
||||
|
||||
$$v_{min} = \frac{w_b \cdot \dot{\psi}_{max}}{tan(\delta_{max})}$$
|
||||
|
||||
with $w_b:$ Wheel base ([RA_WHEEL_BASE](#RA_WHEEL_BASE)), $\dot{\psi}_{max}:$ Maximum yaw rate ([RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM)) and $\delta_{max}:$ Maximum steering angle ([RA_MAX_STR_ANG](#RA_MAX_STR_ANG)).
|
||||
|
||||
## Parameter Overview
|
||||
|
||||
List of all parameters of the ackermann rover module:
|
||||
|
||||
| 매개변수 | 설명 | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------- | ------- |
|
||||
| <a id="RA_WHEEL_BASE"></a>[RA_WHEEL_BASE](../advanced_config/parameter_reference.md#RA_WHEEL_BASE) | Wheel base | m |
|
||||
| <a id="RA_MAX_STR_ANG"></a>[RA_MAX_STR_ANG](../advanced_config/parameter_reference.md#RA_MAX_STR_ANG) | Maximum steering angle | deg |
|
||||
| <a id="RO_MAX_THR_SPEED"></a>[RO_MAX_THR_SPEED](../advanced_config/parameter_reference.md#RO_MAX_THR_SPEED) | Speed the rover drives at maximum throttle | m/s |
|
||||
| <a id="RO_YAW_RATE_LIM"></a>[RO_YAW_RATE_LIM](../advanced_config/parameter_reference.md#RO_YAW_RATE_LIM) | Maximum allowed yaw rate | m/s^2 |
|
||||
| <a id="RO_YAW_RATE_P"></a>[RO_YAW_RATE_P](../advanced_config/parameter_reference.md#RO_YAW_RATE_P) | Proportional gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_RATE_I"></a>[RO_YAW_RATE_I](../advanced_config/parameter_reference.md#RO_YAW_RATE_I) | Integral gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_P"></a>[RO_YAW_P](../advanced_config/parameter_reference.md#RO_YAW_P) | Proportional gain for yaw controller | - |
|
||||
| <a id="RO_SPEED_LIM"></a>[RO_SPEED_LIM](../advanced_config/parameter_reference.md#RO_SPEED_LIM) | Maximum allowed speed | m/s |
|
||||
| <a id="RO_SPEED_P"></a>[RO_SPEED_P](../advanced_config/parameter_reference.md#RO_SPEED_P) | Proportional gain for speed controller | - |
|
||||
| <a id="RO_SPEED_I"></a>[RO_SPEED_I](../advanced_config/parameter_reference.md#RO_SPEED_I) | Integral gain for speed controller | - |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter for pure pursuit | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="NAV_ACC_RAD"></a>[NAV_ACC_RAD](../advanced_config/parameter_reference.md#NAV_ACC_RAD) | Default acceptance radius | m |
|
||||
| <a id="RA_STR_RATE_LIM"></a>[RA_STR_RATE_LIM](../advanced_config/parameter_reference.md#RA_STR_RATE_LIM) | (Optional) Maximum allowed steering rate | deg/s |
|
||||
| <a id="RO_ACCEL_LIM"></a>[RO_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_ACCEL_LIM) | (Optional) Maximum allowed acceleration | m/s^2 |
|
||||
| <a id="RO_DECEL_LIM"></a>[RO_DECEL_LIM](../advanced_config/parameter_reference.md#RO_DECEL_LIM) | (Optional) Maximum allowed deceleration | m/s^2 |
|
||||
| <a id="RO_JERK_LIM"></a>[RO_JERK_LIM](../advanced_config/parameter_reference.md#RO_JERK_LIM) | (Optional) Maximum allowed jerk | $m/s^3$ |
|
||||
| <a id="RA_ACC_RAD_MAX"></a>[RA_ACC_RAD_MAX](../advanced_config/parameter_reference.md#RA_ACC_RAD_MAX) | (Optional) Maximum radius the acceptance radius can be scaled to | m |
|
||||
| <a id="RA_ACC_RAD_GAIN"></a>[RA_ACC_RAD_GAIN](../advanced_config/parameter_reference.md#RA_ACC_RAD_GAIN) | (Optional) Tuning parameter for the acceptance radius scaling | - |
|
||||
|
||||
## See Also
|
||||
|
||||
- [Drive Modes (Ackermann Rover)](../flight_modes_rover/ackermann.md).
|
||||
@@ -1,395 +0,0 @@
|
||||
# Configuration/Tuning (Differential Rover)
|
||||
|
||||
This topic provides a step-by-step guide for setting up your [Differential rover](../frames_rover/differential.md).
|
||||
Successive steps enable [drive modes](../flight_modes_rover/differential.md) with more autopilot support and features.
|
||||
|
||||
:::warning
|
||||
Each step is dependent on the previous steps having been completed.
|
||||
Modes will only work properly if the preceding modes have been configured.
|
||||
:::
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To configure the differential rover frame and outputs:
|
||||
|
||||
1. Enable Rover support by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
Note that this is a special build that contains rover-specific modules.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select _Generic Rover Differential_ frame:
|
||||
|
||||
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe is not displayed and you have checked that you are using rover firmware (not the default), you can alternatively enable this frame by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `50000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Use [Actuators Configuration & Testing](../config/actuators.md) to map the motor functions to flight controller outputs.
|
||||
|
||||
## 수동 모드
|
||||
|
||||
:::warning
|
||||
For this mode to work properly the [Basic Setup](#basic-setup) must've already been completed!
|
||||
:::
|
||||
|
||||
The basic setup already covers the minimum setup required to use the rover in [Manual mode](../flight_modes_rover/differential.md#manual-mode).
|
||||
|
||||
This mode is also affected by (optional) acceleration/deceleration limits.
|
||||
As configuration of these limits becomes mandatory for subsequent modes, we do this setup here.
|
||||
|
||||
Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RD_WHEEL_TRACK](#RD_WHEEL_TRACK) [m]: Measure the distance from the centre of the right wheel to the centre of the left wheel.
|
||||
|
||||
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: Drive the rover at full throttle and set this parameter to the observed value of the ground speed.
|
||||
|
||||
:::info
|
||||
This parameter is also used for the feed-forward term of the speed control.
|
||||
It will be further tuned in the configuration of [Position mode](#position-mode).
|
||||
|
||||
:::
|
||||
|
||||
3. (Optional) [RO_ACCEL_LIM](#RO_ACCEL_LIM) [m/s^2]: Maximum acceleration you want to allow for your rover.
|
||||
|
||||
<a id="RO_ACCEL_LIM_CONSIDERATIONS"></a>
|
||||
|
||||
:::tip
|
||||
Your rover has a maximum possible acceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. From a standstill, give the rover full throttle until it reaches the maximum speed.
|
||||
2. Disarm the rover and plot the `measured_speed_body_x` from [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md).
|
||||
3. Divide the maximum speed by the time it took to reach it and set this as the value for [RO_ACCEL_LIM](#RO_ACCEL_LIM).
|
||||
|
||||
Some RC rovers have enough torque to lift up if the maximum acceleration is not limited.
|
||||
If that is the case:
|
||||
|
||||
4. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to a low value, give the rover full throttle from a standstill and observe its behaviour.
|
||||
5. Increase [RO_ACCEL_LIM](#RO_ACCEL_LIM) until the rover starts to lift up during the acceleration.
|
||||
6. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
4. (Optional) [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2]: Maximum deceleration you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
The same [considerations](#RO_ACCEL_LIM_CONSIDERATIONS) as in the configuration of [RO_ACCEL_LIM](#RO_ACCEL_LIM) apply.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
This parameter is also used for the calculation of the speed setpoint during [Auto modes](#auto-modes).
|
||||
|
||||
:::
|
||||
|
||||
## Acro Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Manual mode](#manual-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
To set up [Acro mode](../flight_modes_rover/differential.md#acro-mode), navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) [deg/s]: This is the maximum yaw rate you want to allow for your rover.
|
||||
This will define the stick-to-yaw-rate mapping for all manual modes using closed loop yaw control and set an upper limit for the yaw rate setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RD_MAX_THR_YAW_R](#RD_MAX_THR_YAW_R) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop yaw rate control.
|
||||
The controller calculates the required speed difference between the left and right motor to achieve the desired yaw rate.
|
||||
This desired speed difference is then linearly mapped to normalized motor commands.
|
||||
To get a good starting value for this parameter drive the rover in manual mode forwards at full throttle and note the ground speed of the vehicle.
|
||||
Then enter _half_ this value for the parameter. <a id="RD_YAW_RATE_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter, first make sure you set [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I) to zero.
|
||||
This way the yaw rate is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
Now put the rover in [Acro mode](../flight_modes_rover/differential.md#acro-mode) and then move the right-stick of your controller to the right and/or left and hold it at a few different levels for a couple of seconds each.
|
||||
Disarm the rover and from the flight log plot the `adjusted_yaw_rate_setpoint` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the actual yaw rate of the rover is higher than the yaw rate setpoint, increase [RD_MAX_THR_YAW_R](#RD_MAX_THR_YAW_R).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_YAW_RATE_P](#RO_YAW_RATE_P) [-]: Proportional gain of the closed loop yaw rate controller.
|
||||
Unlike the feed-forward part of the controller, the closed loop yaw rate control will compare the yaw rate setpoint with the measured yaw rate and adapt to motor commands based on the error between them.
|
||||
The proportional gain is multiplied with this error and that value is added to the motor command.
|
||||
This compensates for disturbances such as uneven ground and external forces.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RD_MAX_THR_YAW_R](#RD_YAW_RATE_P_TUNING).
|
||||
If you tuned [RD_MAX_THR_YAW_R](#RD_MAX_THR_YAW_R) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_YAW_RATE_I](#RO_YAW_RATE_I) [-]: Integral gain of the closed loop yaw controller.
|
||||
The integral gain accumulates the error between the desired and actual yaw rate scaled by the integral gain over time and that value is added to the motor command.
|
||||
|
||||
::: tip
|
||||
An integrator might not be neccessary at this stage, but it will become important for subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
5. (Optional) [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM) and [RO_YAW_DECEL_LIM](#RO_YAW_DECEL_LIM) [deg/s^2]:
|
||||
This is the maximum yaw acceleration and deceleration you want to allow for your rover.
|
||||
This can be used to smooth the `yaw_rate` setpoints and make their trajectory feasible based on the physical limitations of the rover.
|
||||
It also improves tracking and avoid integrator build up.
|
||||
|
||||
::: tip
|
||||
Your rover has a maximum possible yaw acceleration/deceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. Put the rover into [Manual mode](../flight_modes_rover/differential.md#manual-mode).
|
||||
2. From a standstill, move the right stick all the way to the right or left until the rover reaches the maximum yaw rate then return the right stick to the middle.
|
||||
3. Disarm the rover and plot the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md).
|
||||
4. Divide the maximum yaw rate by the time it took to reach it and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
5. Divide the maximum yaw rate by the time it took to return to a standstill and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Acro mode](../flight_modes_rover/differential.md#acro-mode).
|
||||
|
||||
## Stabilized Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Acro mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
For [Stabilized mode](../flight_modes_rover/differential.md#stabilized-mode) the controller utilizes a closed loop yaw controller, which creates a yaw rate setpoint to control the yaw when it is active:
|
||||
|
||||
|
||||
|
||||
Unlike the closed loop yaw rate, this controller has no feed-forward term.
|
||||
Therefore you only need to tune the closed loop gains:
|
||||
|
||||
1. [RO_YAW_P](#RO_YAW_P) [-]: Proportional gain for the closed loop yaw controller.
|
||||
|
||||
::: tip
|
||||
In stabilized mode the closed loop yaw control is only active when driving a straight line (no yaw rate input).
|
||||
|
||||
1. Start with a value of 1 for [RO_YAW_P](#RO_YAW_P).
|
||||
2. Put the rover into stabilized mode and move the left stick of your controller up and/or down to drive forwards/backwards.
|
||||
3. Disarm the rover and from the flight log plot the `measured_yaw` and the `adjusted_yaw_setpoint` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) message over each other.
|
||||
4. Increase/Decrease the parameter until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
For the closed loop yaw control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
Since the yaw and yaw rate controllers are cascaded, there only needs to be one integrator which is in the yaw rate controller.
|
||||
If you observe a steady state error in the yaw setpoint increase the [RO_YAW_RATE_I](#RO_YAW_RATE_I) parameter.
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Stabilized mode](../flight_modes_rover/differential.md#stabilized-mode).
|
||||
|
||||
## Position Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Stabilized mode](#stabilized-mode) must already be configured!
|
||||
:::
|
||||
|
||||
[Position mode](../flight_modes_rover/differential.md#position-mode) is the most advanced manual mode, utilizing closed loop yaw rate, yaw and speed control and leveraging position estimates.
|
||||
|
||||
To configure set the following parameters:
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM) [m/s]: This is the maximum speed you want to allow for your rover.
|
||||
This will define the stick-to-speed mapping for position mode and set an upper limit for the speed setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop speed control which linearly maps desired speeds to normalized motor commands.
|
||||
A good starting point is the observed ground speed when the rover drives at maximum throttle in [Manual mode](../flight_modes_rover/differential.md#manual-mode).
|
||||
|
||||
<a id="RD_SPEED_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter:
|
||||
|
||||
1. Set [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I) to zero.
|
||||
This way the speed is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and then move the left stick of your controller up and/or down and hold it at a few different levels for a couple of seconds each.
|
||||
3. Disarm the rover and from the flight log plot the `adjusted_speed_body_x_setpoint` and the `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
4. If the actual speed of the rover is higher than the speed setpoint, increase [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
::: info
|
||||
If your rover oscillates when driving a straight line in [Position mode](../flight_modes_rover/differential.md#position-mode) just set this parameter to the observed ground speed at maximum throttle in [Manual mode](../flight_modes_rover/differential.md#manual-mode) and complete steps 5-7 first before continuing the tuning of the closed loop speed control (Steps 2-4).
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_SPEED_P](#RO_SPEED_P) [-]: Proportional gain of the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RO_MAX_THR_SPEED](#RD_SPEED_P_TUNING).
|
||||
If you tuned [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_SPEED_I](#RO_SPEED_I) [-]: Integral gain for the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
For the closed loop speed control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
|
||||
:::
|
||||
|
||||
5. [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN): When driving in a straight line (no yaw rate input) position mode leverages the same path following algorithm used in [auto modes](#auto-modes) called [pure pursuit](#pure-pursuit-guidance-logic) to achieve the best possible straight line driving behaviour ([Illustration of control architecture](#pure_pursuit_controller)).
|
||||
This parameter determines how aggressive the controller will steer towards the path.
|
||||
|
||||
::: tip
|
||||
Decreasing the parameter makes it more aggressive but can lead to oscillations.
|
||||
|
||||
To tune this:
|
||||
|
||||
1. Start with a value of 1 for [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN)
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and while driving a straight line at approximately half the maximum speed observe its behaviour.
|
||||
3. If the rover does not drive in a straight line, reduce the value of the parameter, if it oscillates around the path increase the value.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
6. [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN): Minimum threshold for the lookahead distance used by the [pure pursuit algorithm](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and drive at very low speeds, if the rover starts to oscillate even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then increase the value of [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
:::
|
||||
|
||||
7. [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX): Maximum threshold for the lookahead distance used by [pure pursuit](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and drive at very high speeds, if the rover does not drive in a straight line even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then decrease the value of [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Position mode](../flight_modes_rover/differential.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Position mode](#position-mode) must already be configured!
|
||||
:::
|
||||
|
||||
<a id="pure_pursuit_controller"></a>
|
||||
In [auto modes](../flight_modes_rover/differential.md#auto-modes) the autopilot takes over navigation tasks using the following control architecture:
|
||||
|
||||
|
||||
|
||||
The required parameters are separated into the following sections:
|
||||
|
||||
### Speed
|
||||
|
||||
These parameters are used to calculate the speed setpoint in auto modes:
|
||||
|
||||
1. [RO_DECEL_LIM](#RO_DECEL_LIM) ($m/s^2$) and [RO_JERK_LIM](#RO_JERK_LIM) ($m/s^3$) are used to calculate a velocity trajectory such that the rover comes to a smooth stop as it reaches a waypoint.
|
||||
|
||||
::: tip
|
||||
Plan a mission for the rover to drive a square and observe how it slows down when approaching a waypoint:
|
||||
|
||||
- If the rover decelerates too quickly decrease the [RO_DECEL_LIM](#RO_DECEL_LIM) parameter, if it starts slowing down too early increase the parameter.
|
||||
- If you observe a jerking motion as the rover slows down, decrease the [RO_JERK_LIM](#RO_JERK_LIM) parameter otherwise increase it as much as possible as it can interfere with the tuning of [RO_DECEL_LIM](#RO_DECEL_LIM).
|
||||
|
||||
These two parameters have to be tuned as a pair, repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
2. Plot the `adjusted_speed_body_x_setpoint` and `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I).
|
||||
|
||||
The rover only slows down when approaching the waypoint if the angle between the line segment between the previous/current waypoint and current/next waypoint is smaller than 180° - [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN).
|
||||
In other words: The rover slows down only if the expected heading error towards the next waypoint when arriving at the current waypoint is below [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN).
|
||||
|
||||
|
||||
|
||||
For more information on the [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN) parameter see [State Machine](#state-machine).
|
||||
|
||||
### State Machine
|
||||
|
||||
The module employs the following state machine to make full use of a differential rovers ability to turn on the spot:
|
||||
|
||||
|
||||
|
||||
These transition thresholds can be set with [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN) and [RD_TRANS_TRN_DRV](#RD_TRANS_TRN_DRV).
|
||||
|
||||
### Path Following
|
||||
|
||||
The [pure pursuit](#pure-pursuit-guidance-logic) algorithm is used to calculate a desired yaw for the vehicle that is then close loop controlled.
|
||||
The close loop yaw rate was tuned in the configuration of the [Stabilized mode](#stabilized-mode) and the pure pursuit was tuned when setting up the [Position mode](#position-mode).
|
||||
During any auto navigation task observe the behaviour of the rover.
|
||||
If you are unsatisfied with the path following, there are 3 steps to take:
|
||||
|
||||
1. Plot the `adjusted_yaw_rate_setpoint` and the `measured_yaw_rate` from the [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
2. Plot the `adjusted_yaw_setpoint` and the `measured_yaw` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the value for [RO_YAW_P](#RO_YAW_RATE_P) and potentially further tune [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
3. Steps 1 and 2 ensures accurate setpoint tracking, if the path following is still unsatisfactory you need to further tune the [pure pursuit](#pure-pursuit-guidance-logic) parameters.
|
||||
|
||||
## Pure Pursuit Guidance Logic
|
||||
|
||||
The desired yaw setpoints are generated using a pure pursuit algorithm:
|
||||
The controller takes the intersection point between a circle around the vehicle and a line segment.
|
||||
In mission mode this line is usually constructed by connecting the previous and current waypoint:
|
||||
|
||||
|
||||
|
||||
The radius of the circle around the vehicle is used to tune the controller and is often referred to as look-ahead distance.
|
||||
|
||||
The look ahead distance sets how aggressive the controller behaves and is defined as $l_d = v \cdot k$.
|
||||
It depends on the velocity $v$ of the rover and a tuning parameter $k$ that can be set with the parameter [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN).
|
||||
|
||||
:::info
|
||||
A lower value of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) makes the controller more aggressive but can lead to oscillations!
|
||||
:::
|
||||
|
||||
The lookahead is constrained between [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX) and [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
If the distance from the path to the rover is bigger than the lookahead distance, the rover will target the point on the path that is closest to the rover.
|
||||
|
||||
To summarize, the following parameters can be used to tune the controller:
|
||||
|
||||
| 매개변수 | 설명 | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | ---- |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius | m |
|
||||
|
||||
## Parameter Overview
|
||||
|
||||
List of all parameters of the differential rover module:
|
||||
|
||||
| 매개변수 | 설명 | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- | ------- |
|
||||
| <a id="RD_WHEEL_TRACK"></a>[RD_WHEEL_TRACK](../advanced_config/parameter_reference.md#RD_WHEEL_TRACK) | Wheel track | m |
|
||||
| <a id="RD_MAX_THR_YAW_R"></a>[RD_MAX_THR_YAW_R](../advanced_config/parameter_reference.md#RD_MAX_THR_YAW_R) | Yaw rate turning left/right wheels at max speed in opposite directions | m/s |
|
||||
| <a id="RD_TRANS_DRV_TRN"></a>[RD_TRANS_DRV_TRN](../advanced_config/parameter_reference.md#RD_TRANS_DRV_TRN) | Heading error threshold to switch from driving to spot turning | deg |
|
||||
| <a id="RD_TRANS_TRN_DRV"></a>[RD_TRANS_TRN_DRV](../advanced_config/parameter_reference.md#RD_TRANS_TRN_DRV) | Heading error threshold to switch from spot turning to driving | deg |
|
||||
| <a id="RD_MISS_SPD_GAIN"></a>[RD_MISS_SPD_GAIN](../advanced_config/parameter_reference.md#RD_MISS_SPD_GAIN) | Tuning parameter for the speed reduction during waypoint transition | m/s |
|
||||
| <a id="RO_YAW_RATE_LIM"></a>[RO_YAW_RATE_LIM](../advanced_config/parameter_reference.md#RO_YAW_RATE_LIM) | Maximum allowed yaw rate for the rover | deg/s |
|
||||
| <a id="RO_YAW_RATE_P"></a>[RO_YAW_RATE_P](../advanced_config/parameter_reference.md#RO_YAW_RATE_P) | Proportional gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_RATE_I"></a>[RO_YAW_RATE_I](../advanced_config/parameter_reference.md#RO_YAW_RATE_I) | Integral gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_P"></a>[RO_YAW_P](../advanced_config/parameter_reference.md#RO_YAW_P) | Proportional gain for yaw controller | - |
|
||||
| <a id="RO_MAX_THR_SPEED"></a>[RO_MAX_THR_SPEED](../advanced_config/parameter_reference.md#RO_MAX_THR_SPEED) | Speed the rover drives at maximum throttle | m/s |
|
||||
| <a id="RO_SPEED_P"></a>[RO_SPEED_P](../advanced_config/parameter_reference.md#RO_SPEED_P) | Proportional gain for speed controller | - |
|
||||
| <a id="RO_SPEED_I"></a>[RO_SPEED_I](../advanced_config/parameter_reference.md#RO_SPEED_I) | Integral gain for speed controller | - |
|
||||
| <a id="RO_SPEED_LIM"></a>[RO_SPEED_LIM](../advanced_config/parameter_reference.md#RO_SPEED_LIM) | Maximum allowed speed for the rover (and default mission speed). | m/s |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter for pure pursuit | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="RO_ACCEL_LIM"></a>[RO_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_ACCEL_LIM) | (Optional) Maximum allowed acceleration | m/s^2 |
|
||||
| <a id="RO_DECEL_LIM"></a>[RO_DECEL_LIM](../advanced_config/parameter_reference.md#RO_DECEL_LIM) | (Optional) Maximum allowed deceleration | m/s^2 |
|
||||
| <a id="RO_JERK_LIM"></a>[RO_JERK_LIM](../advanced_config/parameter_reference.md#RO_JERK_LIM) | (Optional) Maximum allowed jerk | $m/s^3$ |
|
||||
| <a id="RO_YAW_ACCEL_LIM"></a>[RO_YAW_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_ACCEL_LIM) | (Optional) Maximum allowed yaw acceleration | m/s^2 |
|
||||
| <a id="RO_YAW_DECEL_LIM"></a>[RO_YAW_DECEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_DECEL_LIM) | (Optional) Maximum allowed yaw deceleration | m/s^2 |
|
||||
|
||||
## See Also
|
||||
|
||||
- [Drive Modes (Differential Rover)](../flight_modes_rover/differential.md).
|
||||
@@ -1,396 +0,0 @@
|
||||
# Configuration/Tuning (Mecanum Rover)
|
||||
|
||||
This topic provides a step-by-step guide for setting up your [Mecanum rover](../frames_rover/mecanum.md).
|
||||
Successive steps enable [drive modes](../flight_modes_rover/mecanum.md) with more autopilot support and features.
|
||||
|
||||
:::warning
|
||||
Each step is dependent on the previous steps having been completed.
|
||||
Modes will only work properly if the preceding modes have been configured.
|
||||
:::
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To start using the mecanum rover:
|
||||
|
||||
1. Enable Rover support by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
Note that this is a special build that contains rover-specific modules.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select _Generic Rover Mecanum_ frame:
|
||||
|
||||
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe does not show up in the UI, it can alternatively be selected by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `52000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Use [Actuators Configuration & Testing](../config/actuators.md) to map the motor functions to flight controller outputs.
|
||||
|
||||
## 수동 모드
|
||||
|
||||
:::warning
|
||||
For this mode to work properly the [Basic Setup](#basic-setup) must've already been completed!
|
||||
:::
|
||||
|
||||
The basic setup already covers the minimum setup required to use the rover in [Manual mode](../flight_modes_rover/mecanum.md#manual-mode).
|
||||
|
||||
This mode is also affected by (optional) acceleration/deceleration limits.
|
||||
As configuration of these limits becomes mandatory for subsequent modes, we do this setup here.
|
||||
|
||||
Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RM_WHEEL_TRACK](#RM_WHEEL_TRACK) [m]: Measure the distance from the centre of the right wheel to the centre of the left wheel.
|
||||
|
||||
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: Drive the rover at full throttle and set this parameter to the observed value of the ground speed.
|
||||
|
||||
:::info
|
||||
This parameter is also used for the feed-forward term of the speed control.
|
||||
It will be further tuned in the configuration of [Position mode](#position-mode).
|
||||
|
||||
:::
|
||||
|
||||
3. (Optional) [RO_ACCEL_LIM](#RO_ACCEL_LIM) [m/s^2]: Maximum acceleration you want to allow for your rover.
|
||||
|
||||
<a id="RO_ACCEL_LIM_CONSIDERATIONS"></a>
|
||||
|
||||
:::tip
|
||||
Your rover has a maximum possible acceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. From a standstill, give the rover full throttle until it reaches the maximum speed.
|
||||
2. Disarm the rover and plot the `measured_speed_body_x` from [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md).
|
||||
3. Divide the maximum speed by the time it took to reach it and set this as the value for [RO_ACCEL_LIM](#RO_ACCEL_LIM).
|
||||
|
||||
Some RC rovers have enough torque to lift up if the maximum acceleration is not limited.
|
||||
If that is the case:
|
||||
|
||||
4. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to a low value, give the rover full throttle from a standstill and observe its behaviour.
|
||||
5. Increase [RO_ACCEL_LIM](#RO_ACCEL_LIM) until the rover starts to lift up during the acceleration.
|
||||
6. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
4. (Optional) [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2]: Maximum deceleration you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
The same [considerations](#RO_ACCEL_LIM_CONSIDERATIONS) as in the configuration of [RO_ACCEL_LIM](#RO_ACCEL_LIM) apply.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
This parameter is also used for the calculation of the speed setpoint during [Auto modes](#auto-modes).
|
||||
|
||||
:::
|
||||
|
||||
## Acro Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Manual mode](#manual-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
To set up [Acro mode](../flight_modes_rover/mecanum.md#acro-mode) navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) [deg/s]: This is the maximum yaw rate you want to allow for your rover.
|
||||
This will define the stick-to-yaw-rate mapping for all manual modes using closed loop yaw control and set an upper limit for the yaw rate setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RM_MAX_THR_YAW_R](#RM_MAX_THR_YAW_R) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop yaw rate control.
|
||||
The controller calculates the required speed difference between the left and right motor to achieve the desired yaw rate.
|
||||
This desired speed difference is then linearly mapped to normalized motor commands.
|
||||
To get a good starting value for this parameter drive the rover in manual mode forwards at full throttle and note the ground speed of the vehicle.
|
||||
Then enter _half_ this value for the parameter. <a id="RM_YAW_RATE_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter, first make sure you set [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I) to zero.
|
||||
This way the yaw rate is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
Now put the rover in [Acro mode](../flight_modes_rover/mecanum.md#acro-mode) and then move the right-stick of your controller to the right and/or left and hold it at a few different levels for a couple of seconds each.
|
||||
Disarm the rover and from the flight log plot the `adjusted_yaw_rate_setpoint` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the actual yaw rate of the rover is higher than the yaw rate setpoint, increase [RM_MAX_THR_YAW_R](#RM_MAX_THR_YAW_R).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_YAW_RATE_P](#RO_YAW_RATE_P) [-]: Proportional gain of the closed loop yaw rate controller.
|
||||
Unlike the feed-forward part of the controller, the closed loop yaw rate control will compare the yaw rate setpoint with the measured yaw rate and adapt to motor commands based on the error between them.
|
||||
The proportional gain is multiplied with this error and that value is added to the motor command.
|
||||
This compensates for disturbances such as uneven ground and external forces.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RM_MAX_THR_YAW_R](#RM_YAW_RATE_P_TUNING).
|
||||
If you tuned [RM_MAX_THR_YAW_R](#RM_MAX_THR_YAW_R) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_YAW_RATE_I](#RO_YAW_RATE_I) [-]: Integral gain of the closed loop yaw controller.
|
||||
The integral gain accumulates the error between the desired and actual yaw rate scaled by the integral gain over time and that value is added to the motor command.
|
||||
|
||||
::: tip
|
||||
An integrator might not be neccessary at this stage, but it will become important for subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
5. (Optional) [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM) and [RO_YAW_DECEL_LIM](#RO_YAW_DECEL_LIM) [deg/s^2]: This is the maximum yaw acceleration and deceleration you want to allow for your rover.
|
||||
This can be used to smooth the `yaw_rate` setpoints and make their trajectory feasible based on the physical limitation on the rover to improve tracking and avoid integrator build up.
|
||||
|
||||
::: tip
|
||||
Your rover has a maximum possible yaw acceleration/deceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. Put the rover into [Manual mode](../flight_modes_rover/mecanum.md#manual-mode).
|
||||
2. From a standstill, move the right stick all the way to the right or left until the rover reaches the maximum yaw rate then return the right stick to the middle.
|
||||
3. Disarm the rover and plot the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md).
|
||||
4. Divide the maximum yaw rate by the time it took to reach it and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
5. Divide the maximum yaw rate by the time it took to return to a standstill and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Acro mode](../flight_modes_rover/mecanum.md#acro-mode).
|
||||
|
||||
## Stabilized Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Acro mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
For [Stabilized mode](../flight_modes_rover/mecanum.md#stabilized-mode) the controller utilizes a closed loop yaw controller, which creates a yaw rate setpoint to control the yaw when it is active:
|
||||
|
||||
|
||||
|
||||
Unlike the closed loop yaw rate, this controller has no feed-forward term.
|
||||
Therefore you only need to tune the closed loop gains:
|
||||
|
||||
1. [RO_YAW_P](#RO_YAW_P) [-]: Proportional gain for the closed loop yaw controller.
|
||||
|
||||
::: tip
|
||||
In stabilized mode the closed loop yaw control is only active when driving a straight line (no yaw rate input).
|
||||
Start with a value of 1 for [RO_YAW_P](#RO_YAW_P).
|
||||
Put the rover into stabilized mode and move the left stick of your controller up and/or down to drive forwards/backwards.
|
||||
Disarm the rover and from the flight log plot the `measured_yaw` and the `adjusted_yaw_setpoint` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) message over each other.
|
||||
Increase/Decrease the parameter until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
For the closed loop yaw control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
Since the yaw and yaw rate controllers are cascaded, there only needs to be one integrator which is in the yaw rate controller.
|
||||
If you observe a steady state error in the yaw setpoint increase the [RO_YAW_RATE_I](#RO_YAW_RATE_I) parameter.
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Stabilized mode](../flight_modes_rover/mecanum.md#stabilized-mode).
|
||||
|
||||
## Position Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Stabilized mode](#stabilized-mode) must already be configured!
|
||||
:::
|
||||
|
||||
[Position mode](../flight_modes_rover/mecanum.md#position-mode) is the most advanced manual mode, utilizing closed loop yaw rate, yaw and speed control and leveraging position estimates.
|
||||
|
||||
To configure set the following parameters:
|
||||
|
||||
:::info
|
||||
The speed control in longitudinal and lateral direction use the same tuning parameters.
|
||||
:::
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM) [m/s]: This is the maximum speed you want to allow for your rover.
|
||||
This will define the stick-to-speed mapping for position mode and set an upper limit for the speed setpoint for all [auto modes](#auto-modes).
|
||||
For mecanum rovers the speed is defined in the direction of travel (magnitude of the velocity vector consisting of the longitudinal and lateral speed).
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop speed control which linearly maps desired speeds to normalized motor commands.
|
||||
A good starting point is the observed ground speed when the rover drives at maximum throttle in [Manual mode](../flight_modes_rover/mecanum.md#manual-mode).
|
||||
|
||||
<a id="RD_SPEED_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter:
|
||||
|
||||
1. Set [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I) to zero.
|
||||
This way the speed is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and then move the left stick of your controller up and/or down and hold it at a few different levels for a couple of seconds each.
|
||||
3. Disarm the rover and from the flight log plot the `adjusted_speed_body_x_setpoint` and the `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
4. If the actual speed of the rover is higher than the speed setpoint, increase [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
::: info
|
||||
If your rover oscillates when driving a straight line in [Position mode](../flight_modes_rover/mecanum.md#position-mode) just set this parameter to the observed ground speed at maximum throttle in [Manual mode](../flight_modes_rover/mecanum.md#manual-mode) and complete steps 5-7 first before continuing the tuning of the closed loop speed control (Steps 2-4).
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_SPEED_P](#RO_SPEED_P) [-]: Proportional gain of the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RO_MAX_THR_SPEED](#RD_SPEED_P_TUNING).
|
||||
If you tuned [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_SPEED_I](#RO_SPEED_I) [-]: Integral gain for the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
For the closed loop speed control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
|
||||
:::
|
||||
|
||||
5. [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN): When driving in a straight line (no yaw rate input) position mode leverages the same path following algorithm used in [auto modes](#auto-modes) called [pure pursuit](#pure-pursuit-guidance-logic) to achieve the best possible straight line driving behaviour ([Illustration of control architecture](#pure_pursuit_controller)).
|
||||
This parameter determines how aggressive the controller will steer towards the path.
|
||||
|
||||
::: tip
|
||||
Decreasing the parameter makes it more aggressive but can lead to oscillations.
|
||||
|
||||
To tune this:
|
||||
|
||||
1. Start with a value of 1 for [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN)
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and while driving a straight line at approximately half the maximum speed observe its behaviour.
|
||||
3. If the rover does not drive in a straight line, reduce the value of the parameter, if it oscillates around the path increase the value.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
6. [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN): Minimum threshold for the lookahead distance used by the [pure pursuit algorithm](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and drive at very low speeds, if the rover starts to oscillate even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then increase the value of [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
:::
|
||||
|
||||
7. [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX): Maximum threshold for the lookahead distance used by [pure pursuit](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and drive at very high speeds, if the rover does not drive in a straight line even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then decrease the value of [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Position mode](../flight_modes_rover/mecanum.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Position mode](#position-mode) must already be configured!
|
||||
:::
|
||||
|
||||
<a id="pure_pursuit_controller"></a>
|
||||
In [auto modes](../flight_modes_rover/mecanum.md#auto-modes) the autopilot takes over navigation tasks using the following control architecture:
|
||||
|
||||
|
||||
|
||||
The mecanum module fully leverages the omnidirectionality of this type of rover by maintaining the initial heading of the rover during the entire mission (see [Pure Pursuit Guidance Logic](#pure-pursuit-guidance-logic)).
|
||||
|
||||
The required parameters are separated into the following sections:
|
||||
|
||||
### Speed
|
||||
|
||||
These parameters are used to calculate the velocity setpoint in auto modes:
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM): Sets the default speed ($m/s$) for the rover during the mission (as well as the maximum speed).
|
||||
For mecanum rovers the speed is defined in the direction of travel (magnitude of the velocity vector consisting of the longitudinal and lateral speed).
|
||||
|
||||
2. [RO_DECEL_LIM](#RO_DECEL_LIM) ($m/s^2$) and [RO_JERK_LIM](#RO_JERK_LIM) ($m/s^3$) are used to calculate a velocity trajectory such that the rover comes to a smooth stop as it reaches a waypoint.
|
||||
|
||||
::: tip
|
||||
Plan a mission for the rover to drive a square and observe how it slows down when approaching a waypoint:
|
||||
|
||||
- If the rover decelerates too quickly decrease the [RO_DECEL_LIM](#RO_DECEL_LIM) parameter, if it starts slowing down too early increase the parameter.
|
||||
- If you observe a jerking motion as the rover slows down, decrease the [RO_JERK_LIM](#RO_JERK_LIM) parameter otherwise increase it as much as possible as it can interfere with the tuning of [RO_DECEL_LIM](#RO_DECEL_LIM).
|
||||
|
||||
These two parameters have to be tuned as a pair, repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
3. [RM_MISS_SPD_GAIN](#RM_MISS_SPD_GAIN): The rover slows down when approaching a waypoint based on the angle between the line segment from the previous to current waypoint and current to next waypoint.
|
||||
How much the rover slows down can be tuned with this parameter:
|
||||
|
||||
$$
|
||||
v_{transition} = v_{max} \cdot (1 - \theta_{normalized} * k)
|
||||
$$
|
||||
|
||||
with:
|
||||
|
||||
- $v_{transition}:$ Transition speed
|
||||
- $v_{max}:$ Maximum speed ([RO_SPEED_LIM](#RO_SPEED_LIM))
|
||||
- $\theta_{normalized}:$ Angle between the line segment of the prev-current and current-next waypoints, normalized from $[0\degree, 180\degree]$ to $[0, 1]$
|
||||
- $k:$ Tuning parameter ([RM_MISS_SPD_GAIN](#RM_MISS_SPD_GAIN)).
|
||||
|
||||
4. Plot the `adjusted_speed_body_x_setpoint` and `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I).
|
||||
|
||||
### Path Following
|
||||
|
||||
The [pure pursuit](#pure-pursuit-guidance-logic) algorithm is used to calculate a desired bearing for the vehicle that is then close loop controlled.
|
||||
For mecanum rovers the path following is achieved by directly controlling the velocity of the rover in direction of the desired bearing.
|
||||
During any auto navigation task observe the behaviour of the rover:
|
||||
|
||||
1. If you are unsatisfied with the path following you need to further tune the [pure pursuit](#pure-pursuit-guidance-logic) parameters.
|
||||
2. If the rover does not maintain its initial heading well enough, adjust the value for [RO_YAW_P](#RO_YAW_RATE_P) and potentially further tune [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
|
||||
## Pure Pursuit Guidance Logic
|
||||
|
||||
The desired bearing setpoints are generated using a pure pursuit algorithm:
|
||||
The controller takes the intersection point between a circle around the vehicle and a line segment.
|
||||
In mission mode this line is usually constructed by connecting the previous and current waypoint:
|
||||
|
||||
|
||||
|
||||
The radius of the circle around the vehicle is used to tune the controller and is often referred to as look-ahead distance.
|
||||
|
||||
The look ahead distance sets how aggressive the controller behaves and is defined as $l_d = v \cdot k$.
|
||||
It depends on the velocity $v$ of the rover and a tuning parameter $k$ that can be set with the parameter [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN).
|
||||
|
||||
:::info
|
||||
A lower value of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) makes the controller more aggressive but can lead to oscillations!
|
||||
:::
|
||||
|
||||
The lookahead is constrained between [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX) and [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
If the distance from the path to the rover is bigger than the lookahead distance, the rover will target the point on the path that is closest to the rover.
|
||||
|
||||
To summarize, the following parameters can be used to tune the controller:
|
||||
|
||||
| 매개변수 | 설명 | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | ---- |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius | m |
|
||||
|
||||
## Parameter Overview
|
||||
|
||||
List of all parameters of the mecanum rover module:
|
||||
|
||||
| 매개변수 | 설명 | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- | ------- |
|
||||
| <a id="RM_WHEEL_TRACK"></a>[RM_WHEEL_TRACK](../advanced_config/parameter_reference.md#RM_WHEEL_TRACK) | Wheel track | m |
|
||||
| <a id="RM_MAX_THR_YAW_R"></a>[RM_MAX_THR_YAW_R](../advanced_config/parameter_reference.md#RM_MAX_THR_YAW_R) | Yaw rate turning left/right wheels at max speed in opposite directions | m/s |
|
||||
| <a id="RM_MISS_SPD_GAIN"></a>[RM_MISS_SPD_GAIN](../advanced_config/parameter_reference.md#RM_MISS_SPD_GAIN) | Tuning parameter for the velocity reduction during waypoint transition | - |
|
||||
| <a id="RM_COURSE_CTL_TH"></a>[RM_COURSE_CTL_TH](../advanced_config/parameter_reference.md#RM_COURSE_CTL_TH) | Threshold to update course control in manual position mode | rad |
|
||||
| <a id="RO_YAW_RATE_LIM"></a>[RO_YAW_RATE_LIM](../advanced_config/parameter_reference.md#RO_YAW_RATE_LIM) | Maximum allowed yaw rate for the rover | deg/s |
|
||||
| <a id="RO_YAW_RATE_P"></a>[RO_YAW_RATE_P](../advanced_config/parameter_reference.md#RO_YAW_RATE_P) | Proportional gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_RATE_I"></a>[RO_YAW_RATE_I](../advanced_config/parameter_reference.md#RO_YAW_RATE_I) | Integral gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_P"></a>[RO_YAW_P](../advanced_config/parameter_reference.md#RO_YAW_P) | Proportional gain for yaw controller | - |
|
||||
| <a id="RO_SPEED_LIM"></a>[RO_SPEED_LIM](../advanced_config/parameter_reference.md#RO_SPEED_LIM) | Maximum allowed speed for the rover (and default mission speed). | m/s |
|
||||
| <a id="RO_MAX_THR_SPEED"></a>[RO_MAX_THR_SPEED](../advanced_config/parameter_reference.md#RO_MAX_THR_SPEED) | Speed the rover drives at maximum throttle | m/s |
|
||||
| <a id="RO_SPEED_P"></a>[RO_SPEED_P](../advanced_config/parameter_reference.md#RO_SPEED_P) | Proportional gain for speed controller | - |
|
||||
| <a id="RO_SPEED_I"></a>[RO_SPEED_I](../advanced_config/parameter_reference.md#RO_SPEED_I) | Integral gain for speed controller | - |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter for pure pursuit | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="RO_ACCEL_LIM"></a>[RO_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_ACCEL_LIM) | (Optional) Maximum allowed acceleration | m/s^2 |
|
||||
| <a id="RO_DECEL_LIM"></a>[RO_DECEL_LIM](../advanced_config/parameter_reference.md#RO_DECEL_LIM) | (Optional) Maximum allowed deceleration | m/s^2 |
|
||||
| <a id="RO_JERK_LIM"></a>[RO_JERK_LIM](../advanced_config/parameter_reference.md#RO_JERK_LIM) | (Optional) Maximum allowed jerk | $m/s^3$ |
|
||||
| <a id="RO_YAW_ACCEL_LIM"></a>[RO_YAW_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_ACCEL_LIM) | (Optional) Maximum allowed yaw acceleration | m/s^2 |
|
||||
| <a id="RO_YAW_DECEL_LIM"></a>[RO_YAW_DECEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_DECEL_LIM) | (Optional) Maximum allowed yaw deceleration | m/s^2 |
|
||||
|
||||
## See Also
|
||||
|
||||
- [Drive Modes (Mecanum Rover)](../flight_modes_rover/mecanum.md).
|
||||
@@ -1,161 +0,0 @@
|
||||
# Drive Modes (Ackermann Rover)
|
||||
|
||||
Flight modes (or more accurately "Drive modes" for ground vehicles) provide autopilot support to make it easier to manually drive the vehicle or to execute autonomous missions.
|
||||
|
||||
This section outlines all supported drive modes for [Ackermann rovers](../frames_rover/ackermann.md).
|
||||
|
||||
For information on mapping RC control switches to specific modes see: [Basic Configuration > Flight Modes](../config/flight_mode.md).
|
||||
|
||||
:::warning
|
||||
Selecting any other mode than those listed below will either stop the rover or can lead to undefined behaviour.
|
||||
:::
|
||||
|
||||
## Manual Modes
|
||||
|
||||
Manual modes require stick inputs from the user to drive the vehicle.
|
||||
|
||||
|
||||
|
||||
The sticks provide the same "high level" control effects over direction and rate of movement in all manual modes:
|
||||
|
||||
- `Left stick up/down`: Drive the rover forwards/backwards (controlling speed)
|
||||
- `Right stick left/right`: Make a left/right turn (controlling steering angle ([Manual mode](#manual-mode)) or yaw rate ([Acro](#acro-mode) and [Position](#position-mode))).
|
||||
|
||||
The manual modes provide progressively increasing levels of autopilot support for maintaining a course, speed, and rate of turn, compensating for external factors such as slopes or uneven terrain.
|
||||
|
||||
| Mode | 특징 |
|
||||
| -------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | No autopilot support. User is responsible for keeping the rover on the desired course and maintaining speed and rate of turn. |
|
||||
| [Acro](#acro-mode) | + Maintains the yaw rate (This makes it feel more like driving a car than manual mode). <br>+ Allows maximum yaw rate to be limited (Protects against roll over). |
|
||||
| [Position](#position-mode) | + Maintains the course (Best mode for driving a straight line).<br>+ Maintains speed against disturbances, e.g. when driving up a hill.<br>+ Allows maximum speed to be limited. |
|
||||
|
||||
:::details
|
||||
Overview mode mapping to control effect
|
||||
|
||||
| Mode | Forward/backwards speed | Steering angle/yaw rate | Required measurements |
|
||||
| -------------------------- | ---------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | Directly map stick input to motor command. | Directly map stick input to steering angle. | None. |
|
||||
| [Acro](#acro-mode) | Directly map stick input to motor command. | Stick input creates a yaw rate setpoint for the control system to regulate. | yaw rate. |
|
||||
| [Position](#position-mode) | Stick input creates a speed setpoint for the control system to regulate. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will keep the rover driving in a straight line. | yaw rate, yaw, speed and global position (GPS). |
|
||||
|
||||
:::
|
||||
|
||||
### 수동 모드
|
||||
|
||||
In this mode the stick inputs are directly mapped to motor commands.
|
||||
The rover does not attempt to maintain a specific orientation or compensate for external factors like slopes or uneven terrain!
|
||||
The user is responsible for making the necessary adjustments to the stick inputs to keep the rover on the desired course.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Move the steering angle to the left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Manual mode](../config_rover/ackermann.md#manual-mode).
|
||||
|
||||
### Acro Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate measurement.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint (but does not stabilize heading or regulate speed).
|
||||
|
||||
Yaw rate can be directly mapped to a steering input based on the forward speed of the rover:
|
||||
|
||||
<!-- prettier-ignore -->
|
||||
|
||||
$$\delta = \arctan(\frac{w_b \cdot \dot{\psi}}{v})$$
|
||||
|
||||
with
|
||||
|
||||
- $w_b:$ Wheel base,
|
||||
- $\delta:$ Steering angle,
|
||||
- $\dot{\psi}:$ Yaw rate
|
||||
- $v:$ Forward speed.
|
||||
|
||||
For driving this means that the same right hand stick input will cause a different steering angle based on how fast you are driving.
|
||||
By limiting the maximum yaw rate, we can restrict the steering angle based on the speed, which can prevent the rover from rolling over.
|
||||
This mode will feel more like "driving a car" than [Manual mode](#manual-mode).
|
||||
|
||||
:::info
|
||||
The yaw rate is only close loop controlled when driving forwards.
|
||||
When driving backwards the yaw rate setpoint is directly mapped to a steering angle using the equation above.
|
||||
This is due to the fact that rear wheel steering (driving a car with front-wheel steering backwards) is non-minimum-phase w.r.t to the yaw rate which leads to instabilities when doing closed loop control.
|
||||
:::
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will attempt to maintain a zero yaw rate (minimal disturbance rejection) |
|
||||
|
||||
For the configuration/tuning of this mode see [Acro mode](../config_rover/ackermann.md#acro-mode).
|
||||
|
||||
### Stabilized Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate and yaw estimate.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint and will maintain its heading if this setpoint is zero (but does not regulate speed).
|
||||
Compared to [Acro mode](#acro-mode), this mode is much better at driving in a straight line as it can more effectively reject disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the current yaw. |
|
||||
|
||||
For the configuration/tuning of this mode see [Stabilized mode](../config_rover/ackermann.md#stabilized-mode).
|
||||
|
||||
### Position Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate, yaw, speed and global position estimate.
|
||||
:::
|
||||
|
||||
This is the manual mode with the most autopilot support.
|
||||
The vehicle regulates its yaw rate and speed to a setpoint.
|
||||
If the yaw rate setpoint is zero, the controller will remember the GPS coordinates and yaw (heading) of the vehicle and use those to construct a line that the rover will then follow (course control).
|
||||
This offers the highest amount of disturbance rejection, which leads to the best straight line driving behavior.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| Left stick up/down | Stick position sets a forward/back speed setpoint. The vehicle attempts to maintain this speed on slopes etc. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the course of the rover. |
|
||||
|
||||
For the configuration/tuning of this mode see [Position mode](../config_rover/ackermann.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
In auto modes the autopilot takes over control of the vehicle to run missions, return to launch, or perform other autonomous navigation tasks.
|
||||
For the tuning process see the configuration for [Auto modes](../config_rover/ackermann.md#auto-modes).
|
||||
|
||||
### Mission Mode
|
||||
|
||||
_Mission mode_ is an automatic mode that causes the vehicle to execute a predefined autonomous [mission plan](../flying/missions.md) that has been uploaded to the flight controller.
|
||||
The mission is typically created and uploaded with a Ground Control Station (GCS) application, such as [QGroundControl](https://docs.qgroundcontrol.com/master/en/).
|
||||
|
||||
#### Mission commands
|
||||
|
||||
The following commands can be used in missions at time of writing (PX4 v1.16):
|
||||
|
||||
| QGC mission item | 통신 | 설명 |
|
||||
| ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------- |
|
||||
| Mission start | [MAV_CMD_MISSION_START](MAV_CMD_MISSION_START) | Starts the mission. |
|
||||
| Waypoint | [MAV_CMD_NAV_WAYPOINT](MAV_CMD_NAV_WAYPOINT) | Navigate to waypoint. |
|
||||
| Return to launch | [MAV\_CMD\_NAV\_RETURN\_TO\_LAUNCH][MAV_CMD_NAV_RETURN_TO_LAUNCH] | Return to the launch location. |
|
||||
| Change speed | [MAV\_CMD\_DO\_CHANGE\_SPEED][MAV_CMD_DO_CHANGE_SPEED] | Change the speed setpoint |
|
||||
| Set launch location | [MAV_CMD_DO_SET_HOME](MAV_CMD_DO_SET_HOME) | Changes launch location to specified coordinates. |
|
||||
| Jump to item (all) | [MAV\_CMD\_DO\_JUMP][MAV_CMD_DO_JUMP] (and other jump commands) | Jump to specified mission item. |
|
||||
|
||||
[MAV_CMD_MISSION_START]: https://mavlink.io/en/messages/common.html#MAV_CMD_MISSION_START
|
||||
[MAV_CMD_NAV_WAYPOINT]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_WAYPOINT
|
||||
[MAV_CMD_NAV_RETURN_TO_LAUNCH]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_RETURN_TO_LAUNCH
|
||||
[MAV_CMD_DO_CHANGE_SPEED]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_CHANGE_SPEED
|
||||
[MAV_CMD_DO_SET_HOME]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_SET_HOME
|
||||
[MAV_CMD_DO_JUMP]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_JUMP
|
||||
|
||||
### Return Mode
|
||||
|
||||
This mode uses the [pure pursuit guidance logic](../config_rover/ackermann.md#pure-pursuit-guidance-logic) with the launch position as goal.
|
||||
Return mode can be activated through the respective [mission command](#mission-commands) or through the ground station UI.
|
||||
@@ -1,143 +0,0 @@
|
||||
# Drive Modes (Differential Rover)
|
||||
|
||||
Flight modes (or more accurately "Drive modes" for ground vehicles) provide autopilot support to make it easier to manually drive the vehicle or to execute autonomous missions.
|
||||
|
||||
This section outlines all supported drive modes for differential rovers.
|
||||
|
||||
For information on mapping RC control switches to specific modes see: [Basic Configuration > Flight Modes](../config/flight_mode.md).
|
||||
|
||||
:::warning
|
||||
Selecting any other mode than those listed below will either stop the rover or can lead to undefined behaviour.
|
||||
:::
|
||||
|
||||
## Manual Modes
|
||||
|
||||
Manual modes require stick inputs from the user to drive the vehicle.
|
||||
|
||||
|
||||
|
||||
The sticks provide the same "high level" control effects over direction and rate of movement in all manual modes:
|
||||
|
||||
- `Left stick up/down`: Drive the rover forwards/backwards (controlling speed)
|
||||
- `Right stick left/right`: Rotate the rover to the left/right (controlling yaw rate).
|
||||
|
||||
The manual modes provide progressively increasing levels of autopilot support for maintaining a course, speed, and rate of turn, compensating for external factors such as slopes or uneven terrain.
|
||||
|
||||
| Mode | 특징 |
|
||||
| ------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | No autopilot support. User is responsible for keeping the rover on the desired course and maintaining speed and rate of turn. |
|
||||
| [Acro](#acro-mode) | + Maintains the yaw rate (This makes it slightly better at holding a straight line in uneven terrain). <br>+ Allows maximum yaw rate to be limited. |
|
||||
| [Stabilized](#stabilized-mode) | + Maintans the yaw (This makes it significantly better at holding a straight line). |
|
||||
| [Position](#position-mode) | + Maintains the course (Best mode for driving a straight line).<br>+ Maintains speed against disturbances, e.g. when driving up a hill.<br>+ Allows maximum speed to be limited. |
|
||||
|
||||
:::details
|
||||
Overview mode mapping to control effect
|
||||
|
||||
| Mode | Forwards/backwards speed | Yaw rate | Required measurements |
|
||||
| ------------------------------ | ---------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | Directly map stick input to motor commands. | Directly map stick input to motor commands. | None. |
|
||||
| [Acro](#acro-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. | Yaw rate. |
|
||||
| [Stabilized](#stabilized-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will maintain the current yaw (heading) of the rover. | Yaw rate and yaw. |
|
||||
| [Position](#position-mode) | Stick input creates a speed setpoint for the control system to regulate. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will keep the rover driving in a straight line. | Yaw rate, yaw, speed and global position (GPS). |
|
||||
|
||||
:::
|
||||
|
||||
### 수동 모드
|
||||
|
||||
In this mode the stick inputs are directly mapped to motor commands. The rover does not attempt to maintain a specific orientation or compensate for external factors like slopes or uneven terrain!
|
||||
The user is responsible for making the necessary adjustments to the stick inputs to keep the rover on the desired course.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | --------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Yaw the rover to the left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Manual mode](../config_rover/differential.md#manual-mode).
|
||||
|
||||
### Acro Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate measurement.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint (but does not stabilize heading or regulate speed).
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will attempt to maintain a zero yaw rate (minimal disturbance rejection) |
|
||||
|
||||
For the configuration/tuning of this mode see [Acro mode](../config_rover/differential.md#acro-mode).
|
||||
|
||||
### Stabilized Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate and yaw estimate.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint and will maintain its heading if this setpoint is zero (but does not regulate speed).
|
||||
Compared to [Acro mode](#acro-mode), this mode is much better at driving in a straight line as it can more effectively reject disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the current yaw. |
|
||||
|
||||
For the configuration/tuning of this mode see [Stabilized mode](../config_rover/differential.md#stabilized-mode).
|
||||
|
||||
### Position Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate, yaw, speed and global position estimate.
|
||||
:::
|
||||
|
||||
This is the manual mode with the most autopilot support.
|
||||
The vehicle regulates its yaw rate and speed to a setpoint.
|
||||
If the yaw rate setpoint is zero, the controller will remember the GNSS coordinates and yaw (heading) of the vehicle and use those to construct a line that the rover will then follow (course control).
|
||||
This offers the highest amount of disturbance rejection, which leads to the best straight line driving behavior.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| Left stick up/down | Create a speed setpoint for the control system to regulate. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the course of the rover. |
|
||||
|
||||
For the configuration/tuning of this mode see [Position mode](../config_rover/differential.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
In auto modes the autopilot takes over control of the vehicle to run missions, return to launch, or perform other autonomous navigation tasks.
|
||||
For the configuration/tuning of these modes see [Auto Modes](../config_rover/differential.md#auto-modes).
|
||||
|
||||
### Mission Mode
|
||||
|
||||
_Mission mode_ is an automatic mode in which the vehicle executes a predefined autonomous [mission plan](../flying/missions.md) that has been uploaded to the flight controller.
|
||||
The mission is typically created and uploaded with a Ground Control Station (GCS) application, such as [QGroundControl](https://docs.qgroundcontrol.com/master/en/).
|
||||
|
||||
#### Mission commands
|
||||
|
||||
The following commands can be used in missions at time of writing (PX4 v1.16):
|
||||
|
||||
| QGC mission item | 통신 | 설명 |
|
||||
| ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------ |
|
||||
| Mission start | [MAV_CMD_MISSION_START](MAV_CMD_MISSION_START) | Starts the mission. |
|
||||
| Waypoint | [MAV_CMD_NAV_WAYPOINT](MAV_CMD_NAV_WAYPOINT) | Navigate to waypoint. |
|
||||
| Return to launch | [MAV\_CMD\_NAV\_RETURN\_TO\_LAUNCH][MAV_CMD_NAV_RETURN_TO_LAUNCH] | Return to the launch location. |
|
||||
| Delay until | [MAV_CMD_NAV_DELAY](MAV_CMD_NAV_DELAY) | The rover will stop for a specified amount of time. |
|
||||
| Change speed | [MAV\_CMD\_DO\_CHANGE\_SPEED][MAV_CMD_DO_CHANGE_SPEED] | Change the speed setpoint |
|
||||
| Set launch location | [MAV_CMD_DO_SET_HOME](MAV_CMD_DO_SET_HOME) | Changes launch location to specified coordinates. |
|
||||
| Jump to item (all) | [MAV\_CMD\_DO\_JUMP][MAV_CMD_DO_JUMP] (and other jump commands) | Jump to specified mission item. |
|
||||
| Loiter (all) | [MAV\_CMD\_NAV\_LOITER\_TIME][MAV_CMD_NAV_LOITER_TIME] (and other loiter commands) | Stop the rover for given time. Other commands stop indefinitely. |
|
||||
|
||||
[MAV_CMD_MISSION_START]: https://mavlink.io/en/messages/common.html#MAV_CMD_MISSION_START
|
||||
[MAV_CMD_NAV_WAYPOINT]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_WAYPOINT
|
||||
[MAV_CMD_NAV_RETURN_TO_LAUNCH]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_RETURN_TO_LAUNCH
|
||||
[MAV_CMD_NAV_DELAY]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_DELAY
|
||||
[MAV_CMD_DO_CHANGE_SPEED]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_CHANGE_SPEED
|
||||
[MAV_CMD_DO_SET_HOME]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_SET_HOME
|
||||
[MAV_CMD_NAV_LOITER_TIME]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_LOITER_TIME
|
||||
[MAV_CMD_DO_JUMP]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_JUMP
|
||||
|
||||
### Return Mode
|
||||
|
||||
This mode uses the [pure pursuit guidance logic](../config_rover/differential.md#pure-pursuit-guidance-logic) with the launch position as goal.
|
||||
Return mode can be activated through the respective [mission command](#mission-commands) or through the ground station UI.
|
||||
@@ -1,168 +0,0 @@
|
||||
# Drive Modes (Mecanum Rover)
|
||||
|
||||
Flight modes (or more accurately "Drive modes" for ground vehicles) provide autopilot support to make it easier to manually drive the vehicle or to execute autonomous missions.
|
||||
|
||||
This section outlines all supported drive modes for mecanum rovers.
|
||||
|
||||
For information on mapping RC control switches to specific modes see: [Basic Configuration > Flight Modes](../config/flight_mode.md).
|
||||
|
||||
:::warning
|
||||
Selecting any other mode than those listed below will either stop the rover or can lead to undefined behaviour.
|
||||
:::
|
||||
|
||||
## Manual Modes
|
||||
|
||||
Manual modes require stick inputs from the user to drive the vehicle.
|
||||
|
||||
|
||||
|
||||
The sticks provide the same "high level" control effects over direction and rate of movement in all manual modes:
|
||||
|
||||
- `Left stick up/down`: Drive the rover forwards/backwards (controlling speed)
|
||||
- `Left stick left/right`: Yaw the rover to the left/right (controlling yaw rate).
|
||||
- `Right stick left/right`: Drive the rover left/right (controlling speed).
|
||||
|
||||
The manual modes provide progressively increasing levels of autopilot support for maintaining a course, speed, and rate of turn, compensating for external factors such as slopes or uneven terrain.
|
||||
|
||||
| Mode | 특징 |
|
||||
| ------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| [Manual](#manual-mode) | No autopilot support. User is responsible for keeping the rover on the desired course and maintaining speed and rate of turn. |
|
||||
| [Acro](#acro-mode) | + Maintains yaw rate (This makes it slightly better at holding a straight line in uneven terrain). <br>+ Allows maximum yaw rate to be limited. |
|
||||
| [Stabilized](#stabilized-mode) | + Maintains yaw (This makes it significantly better at holding a straight line) . |
|
||||
| [Position](#position-mode) | + Best mode for holding a straight line.<br>+ Maintains speed against disturbances, e.g. when driving up a hill<br>+ Allows maximum speed to be limited. |
|
||||
|
||||
:::details
|
||||
Overview mode mapping to control effect
|
||||
|
||||
| Mode | Longitudinal/Lateral speed | Yaw rate | Required measurements |
|
||||
| ------------------------------ | ------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | Directly map stick input to motor commands. | Directly map stick input to motor commands. | None. |
|
||||
| [Acro](#acro-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. | Yaw rate. |
|
||||
| [Stabilized](#stabilized-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will maintain the current yaw (heading) of the rover. | Yaw rate and yaw. |
|
||||
| [Position](#position-mode) | Stick input creates a velocity setpoint for the control system to regulate. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will keep the rover driving in a straight line. | Yaw rate, yaw, velocity and global position (GPS). |
|
||||
|
||||
:::
|
||||
|
||||
### 수동 모드
|
||||
|
||||
In this mode the stick inputs are directly mapped to motor commands.
|
||||
The rover does not attempt to maintain a specific orientation or compensate for external factors like slopes or uneven terrain!
|
||||
The user is responsible for making the necessary adjustments to the stick inputs to keep the rover on the desired course.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | --------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Left stick left/right | Yaw the rover to the left/right. |
|
||||
| Right stick left/right | Drive the rover left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Manual mode](../config_rover/mecanum.md#manual-mode).
|
||||
|
||||
### Acro Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate measurement.
|
||||
:::
|
||||
|
||||
The vehicle regulates its yaw rate (Left stick left/right) to a setpoint, and a maximum yaw rate can also be specified.
|
||||
Heading and speed are not controlled.
|
||||
|
||||
Compared to [Manual mode](#manual-mode) this introduces the following new features:
|
||||
|
||||
- The yaw rate control ensures that the rover turns at the requested rate even on different surfaces and due to other external forces (such as wind).
|
||||
- Slightly better at driving in a straight line because if the input is zero PX4 will attempt to maintain a zero yaw rate.
|
||||
This is resistant to minor disturbances.
|
||||
- Upper limit for the yaw rate can be used to tune how aggressive the rover turns.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Left stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will attempt to maintain a zero yaw rate (minimal disturbance rejection) |
|
||||
| Right stick left/right | Drive the rover left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Acro mode](../config_rover/mecanum.md#acro-mode).
|
||||
|
||||
### Stabilized Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate and yaw estimate.
|
||||
:::
|
||||
|
||||
The vehicle regulates its yaw rate to a setpoint, and a maximum yaw rate can also be specified.
|
||||
The vehicle regulates its yaw to a setpoint when the yaw rate setpoint is zero, maintaining the heading.
|
||||
Speed is not controlled.
|
||||
|
||||
Compared to [Acro mode](#acro-mode), this mode is much better at driving in a straight line as it can more effectively reject disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Left stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the current yaw. |
|
||||
| Right stick left/right | Drive the rover left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Stabilized mode](../config_rover/mecanum.md#stabilized-mode).
|
||||
|
||||
### Position Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate, yaw, speed and global position estimate.
|
||||
:::
|
||||
|
||||
This is the mode with the most autopilot support.
|
||||
|
||||
The vehicle regulates its yaw rate to a setpoint, and a maximum yaw rate can also be specified.
|
||||
The path is maintained when the yaw rate setpoint is zero using global position (the controller constructs a line in the direction of the velocity input (forward + lateral speed) that the rover will then follow by tracking the global position).
|
||||
Speed is regulated to a setpoint, and a maximum value can be set.
|
||||
|
||||
Compared to [Stabilized Mode](#stabilized-mode) this introduces the following features:
|
||||
|
||||
- Upper limit for the speed (see [Position Mode](../config_rover/mecanum.md#position-mode)) to tune how fast the rover is allowed to drive.
|
||||
- The speed control ensures that the rover drives the requested speed even under disturbances (i.e. driving up a hill, against wind, with a heavier payload etc.).
|
||||
- The course control leads to the best straight line driving behaviour, as the vehicle will follow the intended path of the vehicle and return to it if forced off-track
|
||||
This is much better than stabilized mode, which can be forced off the intended track by disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| Left stick up/down | Create a forward speed setpoint for the control system to regulate. |
|
||||
| Left stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the course of the rover. |
|
||||
| Right stick left/right | Create a lateral speed setpoint for the control system to regulate. |
|
||||
|
||||
For the configuration/tuning of this mode see [Position mode](../config_rover/mecanum.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
In auto modes the autopilot takes over control of the vehicle to run missions, return to launch, or perform other autonomous navigation tasks.
|
||||
For the configuration/tuning of these modes see [Auto Modes](../config_rover/mecanum.md#auto-modes).
|
||||
|
||||
### Mission Mode
|
||||
|
||||
_Mission mode_ is an automatic mode in which the vehicle executes a predefined autonomous [mission plan](../flying/missions.md) that has been uploaded to the flight controller.
|
||||
The mission is typically created and uploaded with a Ground Control Station (GCS) application, such as [QGroundControl](https://docs.qgroundcontrol.com/master/en/).
|
||||
|
||||
#### Mission commands
|
||||
|
||||
The following commands can be used in missions at time of writing (PX4 v1.16):
|
||||
|
||||
| QGC mission item | 통신 | 설명 |
|
||||
| ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------ |
|
||||
| Mission start | [MAV_CMD_MISSION_START](MAV_CMD_MISSION_START) | Starts the mission. |
|
||||
| Waypoint | [MAV_CMD_NAV_WAYPOINT](MAV_CMD_NAV_WAYPOINT) | Navigate to waypoint. |
|
||||
| Return to launch | [MAV\_CMD\_NAV\_RETURN\_TO\_LAUNCH][MAV_CMD_NAV_RETURN_TO_LAUNCH] | Return to the launch location. |
|
||||
| Delay until | [MAV_CMD_NAV_DELAY](MAV_CMD_NAV_DELAY) | The rover will stop for a specified amount of time. |
|
||||
| Change speed | [MAV\_CMD\_DO\_CHANGE\_SPEED][MAV_CMD_DO_CHANGE_SPEED] | Change the speed setpoint |
|
||||
| Set launch location | [MAV_CMD_DO_SET_HOME](MAV_CMD_DO_SET_HOME) | Changes launch location to specified coordinates. |
|
||||
| Jump to item (all) | [MAV\_CMD\_DO\_JUMP][MAV_CMD_DO_JUMP] (and other jump commands) | Jump to specified mission item. |
|
||||
| Loiter (all) | [MAV\_CMD\_NAV\_LOITER\_TIME][MAV_CMD_NAV_LOITER_TIME] (and other loiter commands) | Stop the rover for given time. Other commands stop indefinitely. |
|
||||
|
||||
[MAV_CMD_MISSION_START]: https://mavlink.io/en/messages/common.html#MAV_CMD_MISSION_START
|
||||
[MAV_CMD_NAV_WAYPOINT]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_WAYPOINT
|
||||
[MAV_CMD_NAV_RETURN_TO_LAUNCH]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_RETURN_TO_LAUNCH
|
||||
[MAV_CMD_NAV_DELAY]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_DELAY
|
||||
[MAV_CMD_DO_CHANGE_SPEED]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_CHANGE_SPEED
|
||||
[MAV_CMD_DO_SET_HOME]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_SET_HOME
|
||||
[MAV_CMD_NAV_LOITER_TIME]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_LOITER_TIME
|
||||
[MAV_CMD_DO_JUMP]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_JUMP
|
||||
|
||||
### Return Mode
|
||||
|
||||
This mode uses the [pure pursuit guidance logic](../config_rover/mecanum.md#pure-pursuit-guidance-logic) with the launch position as goal.
|
||||
Return mode can be activated through the respective [mission command](#mission-commands) or through the ground station UI.
|
||||
@@ -1,14 +0,0 @@
|
||||
# Ackermann Rovers
|
||||
|
||||
<Badge type="tip" text="PX4 v1.16" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
An _Ackermann rover_ controls its direction by pointing the front wheels in the direction of travel — the [Ackermann steering geometry](https://en.wikipedia.org/wiki/Ackermann_steering_geometry) compensates for the fact that wheels on the inside and outside of the turn move at different rates.
|
||||
This kind of steering is used on most commercial vehicles, including cars, trucks etc.
|
||||
|
||||
:::info
|
||||
PX4 does not require that the vehicle uses the Ackermann geometry and will work with any front-steering rover.
|
||||
:::
|
||||
|
||||
|
||||
|
||||
See [Configuration/Tuning](../config_rover/ackermann.md) to set up your rover and [Drive Modes](../flight_modes_rover/ackermann.md) for the supported flight (aka drive) modes.
|
||||
@@ -1,170 +0,0 @@
|
||||
# Ackermann Rover
|
||||
|
||||
<Badge type="tip" text="main (PX4 v1.16+)" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
An _Ackermann rover_ controls its direction by pointing the front wheels in the direction of travel — the [Ackermann steering geometry](https://en.wikipedia.org/wiki/Ackermann_steering_geometry) compensates for the fact that wheels on the inside and outside of the turn move at different rates.
|
||||
This kind of steering is used on most commercial vehicles, including cars, trucks etc.
|
||||
|
||||
|
||||
|
||||
:::info
|
||||
PX4 does not require that the vehicle uses the Ackermann geometry and will work with any front-steering rover.
|
||||
:::
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To start using the ackermann rover:
|
||||
|
||||
1. Enable the module by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select the _Generic Rover Ackermann_:
|
||||
|
||||
|
||||
|
||||
::: warning
|
||||
Do not use the _Generic Ground Vehicle (Ackermann)_ airframe as that will load the [(Deprecated) Rover Position Control](../frames_rover/rover_position_control.md) module.
|
||||
|
||||
:::
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe is not displayed and you have checked that you are using rover firmware (not the default), you can alternatively enable this frame by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `51000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Open the [Actuators Configuration & Testing](../config/actuators.md) to map the steering and throttle functions to flight controller outputs.
|
||||
|
||||
This is sufficient to drive the the rover in [manual mode](../flight_modes_rover/index.md#manual-mode) (see [Drive modes](../flight_modes_rover/index.md)).
|
||||
|
||||
:::info
|
||||
Many features of this module are disabled by default, and are only enabled by setting certain parameters.
|
||||
The [Tuning (basic)](#tuning-basic) section goes through the minimum setup required to start driving missions
|
||||
and the [Tuning (advanced)](#tuning-advanced) section outlines the remaining features and tuning variables of the module.
|
||||
:::
|
||||
|
||||
## Tuning (Basic)
|
||||
|
||||
To start driving missions navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------- | ---- |
|
||||
| <a id="RA_WHEEL_BASE"></a>[RA_WHEEL_BASE](../advanced_config/parameter_reference.md#RA_WHEEL_BASE) | Wheel-base of the rover which is measured from the back to the front wheel | m |
|
||||
| <a id="RA_MAX_STR_ANG"></a>[RA_MAX_STR_ANG](../advanced_config/parameter_reference.md#RA_MAX_STR_ANG) | Maximum steering angle of the rover | deg |
|
||||
| <a id="RA_MISS_VEL_DEF"></a>[RA_MISS_VEL_DEF](../advanced_config/parameter_reference.md#RA_MISS_VEL_DEF) | Default velocity the rover will drive during the mission | m/s |
|
||||
|
||||
|
||||
|
||||
This is enough to start driving missions, but depending on the rover might not yet lead to satisfactory performance .
|
||||
If that is the case further tuning is required which is outlined in [Mission parameters](#mission-parameters).
|
||||
|
||||
## Tuning (Advanced)
|
||||
|
||||
To get an overview of all parameters that are related to the Ackermann rover module navigate to the _Rover Ackermann_ group in the _Parameters_ section of QGroundControl.
|
||||
|
||||
### General Parameters
|
||||
|
||||
These parameters affect the general behaviour of the rover. This will influence both auto and manual modes.
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------ | ---- |
|
||||
| <a id="RA_MAX_SPEED"></a>[RA_MAX_SPEED](../advanced_config/parameter_reference.md#RA_MAX_SPEED) | Speed the rover drives at maximum throttle | m/s |
|
||||
|
||||
This is used for a feed-forward term on the speed controller in mission mode and necessary for the [acceleration slew rate](#slew-rates).
|
||||
|
||||
#### Slew Rates
|
||||
|
||||
Slew rates limit how fast the signal that is sent to the motors is allowed to change:
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------- | ----- |
|
||||
| <a id="RA_MAX_ACCEL"></a>[RA_MAX_ACCEL](../advanced_config/parameter_reference.md#RA_MAX_ACCEL) | Limit on the acceleration of the rover | m/s^2 |
|
||||
| <a id="RA_MAX_STR_RATE"></a>[RA_MAX_STR_RATE](../advanced_config/parameter_reference.md#RA_MAX_STR_RATE) | Limit on the steering rate | deg/s |
|
||||
|
||||
:::warning
|
||||
The slew rates are not based on measurements but on assumed linear relation between the throttle input and [RA_MAX_SPEED](#RA_MAX_SPEED) or steering input and [RA_MAX_STR_ANG](#RA_MAX_STR_ANG) respectively.
|
||||
Therefore these two parameters have to be set for the slew rates to work!
|
||||
:::
|
||||
|
||||
## Mission Parameters
|
||||
|
||||
These parameters only affect vehicle in [Mission Mode](../flight_modes_rover/index.md#mission-mode).
|
||||
|
||||
:::warning
|
||||
The parameters in [Tuning (basic)](#tuning-basic) must also be set to drive missions!
|
||||
:::
|
||||
|
||||
The module uses a control algorithm called pure pursuit, see [Pure Pursuit Guidance Logic](../flight_modes_rover/index.md#pure-pursuit-guidance-logic) for the basic tuning process.
|
||||
|
||||
:::info
|
||||
Increasing [PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) can help to make the steering less aggressive at slow speeds.
|
||||
This can be useful especially if the [corner slow down effect](#corner-slow-down) is enabled.
|
||||
:::
|
||||
|
||||
### Cornering Parameters
|
||||
|
||||
#### Corner cutting
|
||||
|
||||
The module employs a special cornering logic causing the rover to "cut corners" to achieve a smooth trajectory.
|
||||
This is done by scaling the acceptance radius based on the corner the rover has to drive (for geometric explanation see [Cornering logic](#mission-cornering-logic-info-only)).
|
||||
|
||||
|
||||
|
||||
The degree to which corner cutting is allowed can be tuned, or disabled, with the following parameters:
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------- | ---- |
|
||||
| <a id="NAV_ACC_RAD"></a>[NAV_ACC_RAD](../advanced_config/parameter_reference.md#NAV_ACC_RAD) | Default acceptance radius | m |
|
||||
| <a id="RA_ACC_RAD_MAX"></a>[RA_ACC_RAD_MAX](../advanced_config/parameter_reference.md#RA_ACC_RAD_MAX) | Maximum radius the acceptance radius can be scaled to | m |
|
||||
| <a id="RA_ACC_RAD_GAIN"></a>[RA_ACC_RAD_GAIN](../advanced_config/parameter_reference.md#RA_ACC_RAD_GAIN) | Tuning parameter | - |
|
||||
|
||||
The tuning parameter is a multiplicand on the calculated ideal acceptance radius to account for dynamic effects.
|
||||
|
||||
#### Corner slow down
|
||||
|
||||
To smoothen the trajectory further and reduce the risk of the rover rolling over, the mission speed is reduced as the rover gets closer to a waypoint:
|
||||
|
||||
- During cornering the rover drives at a speed that is equal to the the inverse of the acceptance radius (calculated using the [corner cutting logic](#corner-cutting)) multiplied with a tuning parameter called [RA_MISS_VEL_GAIN](#RA_MISS_VEL_GAIN).
|
||||
- In between waypoints (straight line) the rover speed is regulated such that it will arrive at the acceptance radius of the waypoint with the desired cornering speed.
|
||||
This requires [RA_MAX_ACCEL](#RA_MAX_ACCEL) and [RA_MAX_JERK](#RA_MAX_JERK) to be set.
|
||||
|
||||
The mission speed is constrained between a minimum allowed speed [RA_MISS_VEL_MIN](#RA_MISS_VEL_MIN) and the default mission speed [RA_MISS_VEL_DEF](#RA_MISS_VEL_DEF).
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------- | ------- |
|
||||
| <a id="RA_MISS_VEL_DEF"></a>[RA_MISS_VEL_DEF](../advanced_config/parameter_reference.md#RA_MISS_VEL_DEF) | Default mission speed | $m/s$ |
|
||||
| <a id="RA_MISS_VEL_MIN"></a>[RA_MISS_VEL_MIN](../advanced_config/parameter_reference.md#RA_MISS_VEL_MIN) | Minimum the speed can be reduced to during cornering | $m/s$ |
|
||||
| <a id="RA_MISS_VEL_GAIN"></a>[RA_MISS_VEL_GAIN](../advanced_config/parameter_reference.md#RA_MISS_VEL_GAIN) | Tuning parameter for the velocity reduction | - |
|
||||
| <a id="RA_MAX_JERK"></a>[RA_MAX_JERK](../advanced_config/parameter_reference.md#RA_MAX_JERK) | Limit for forwards acc/deceleration change. | $m/s^3$ |
|
||||
|
||||
### Mission Cornering Logic (Info only)
|
||||
|
||||
To enable a smooth trajectory, the acceptance radius of waypoints is scaled based on the angle between a line segment from the current-to-previous and current-to-next waypoints.
|
||||
The ideal trajectory would be to arrive at the next line segment with the heading pointing towards the next waypoint.
|
||||
For this purpose the minimum turning circle of the rover is inscribed tangentially to both line segments.
|
||||
|
||||
|
||||
|
||||
The acceptance radius of the waypoint is set to the distance from the waypoint to the tangential points between the circle and the line segments:
|
||||
|
||||
$$
|
||||
\begin{align*}
|
||||
r_{min} &= \frac{L}{\sin\left( \delta_{max}\right) } \\
|
||||
\theta &= \frac{1}{2}\arccos\left( \frac{\vec{a}*\vec{b}}{|\vec{a}||\vec{b}|}\right) \\
|
||||
r_{acc} &= \frac{r_{min}}{\tan\left( \theta\right) }
|
||||
\end{align*}
|
||||
$$
|
||||
|
||||
| Symbol | Description | Unit |
|
||||
| ----------------------------------- | ---------------------------------- | ---- |
|
||||
| $\vec{a}$ | Vector from current to previous WP | m |
|
||||
| $\vec{b}$ | Vector from current to next WP | m |
|
||||
| $r_{min}$ | Minimum turn radius | m |
|
||||
| $\delta_{max}$ | Maximum steer angle | m |
|
||||
| $r_{acc}$ | Acceptance radius | m |
|
||||
|
||||
<!--
|
||||
## Parameters
|
||||
|
||||
The following parameters affect the ackermann-steering rover:
|
||||
-->
|
||||
@@ -1,86 +0,0 @@
|
||||
# Aion Robotics R1 UGV
|
||||
|
||||
<Badge type="tip" text="PX4 v1.15" />
|
||||
|
||||
The [Aion R1](https://www.aionrobotics.com/) vehicle was chosen to test and improve the differential drive support for PX4, and to improve driver support for Roboclaw Motor Controllers, such as the [RoboClaw 2x15A](https://www.basicmicro.com/RoboClaw-2x15A-Motor-Controller_p_10.html).
|
||||
|
||||
The documentation and driver information here should also make it easier to work with Roboclaw controllers on other vehicles, and to work with vehicles like the [Aion R6](https://www.aionrobotics.com/r6).
|
||||
|
||||
Currently, PX4 supports MANUAL mode for this setup.
|
||||
|
||||
|
||||
|
||||
## 부품 목록
|
||||
|
||||
- [Aion R1 (Discontinued)](https://www.aionrobotics.com/)
|
||||
- [Documentation](https://github-docs.readthedocs.io/en/latest/r1-ugv.html)
|
||||
- [RoboClaw 2x15A](https://www.basicmicro.com/RoboClaw-2x15A-Motor-Controller_p_10.html)
|
||||
- [R1 Roboclaw specifications](https://resources.basicmicro.com/aion-robotics-r1-autonomous-robot/)
|
||||
- [Auterion Skynode](../companion_computer/auterion_skynode.md)
|
||||
|
||||
## 조립
|
||||
|
||||
The assembly consists of a 3D-printed frame on which all the autopilot parts were attached.
|
||||
For this build this includes an [Auterion Skynode](../companion_computer/auterion_skynode.md), connected to a Pixhawk Adapter Board that interfaces with the RoboClaw motor controllers over serial.
|
||||
|
||||
|
||||
|
||||
:::info
|
||||
If using a standard Pixhawk you could connect the RoboClaw to the Autopilot without an Adapter Board.
|
||||
:::
|
||||
|
||||
The RoboClaw should be connected to a suitable suitable serial (UART) port on the flight controller, such as `GPS2` or `TELEM1`.
|
||||
Other RoboClaw wiring is detailed in the [RoboClaw User Manual](https://downloads.basicmicro.com/docs/roboclaw_user_manual.pdf) 'Packet Serial Wiring' section and shown below (this setup has been validated for compatibility).
|
||||
|
||||
|
||||
|
||||
## PX4 설정
|
||||
|
||||
### Rover Configuration
|
||||
|
||||
Use _QGroundControl_ for rover configuration:
|
||||
|
||||
1. In the [Basic Configuration](../config/index.md) section, select the [Airframe](../config/airframe.md) tab.
|
||||
2. Choose **Aion Robotics R1 UGV** under the **Rover** category.
|
||||
|
||||
|
||||
|
||||
### RoboClaw Configuration
|
||||
|
||||
First configure the serial connection:
|
||||
|
||||
1. Navigate to the [Parameters](../advanced_config/parameters.md) section in QGroundControl.
|
||||
|
||||
- Set the [RBCLW_SER_CFG](../advanced_config/parameter_reference.md#RBCLW_SER_CFG) parameter to the serial port to which the RoboClaw is connected (such as `GPS2`).
|
||||
- [RBCLW_COUNTS_REV](../advanced_config/parameter_reference.md#RBCLW_COUNTS_REV) specifies the number of encoder counts required for one wheel revolution.
|
||||
This value should be left at `1200` for the tested `RoboClaw 2x15A Motor Controller`.
|
||||
Adjust the value based on your specific encoder and wheel setup.
|
||||
- RoboClaw motor controllers must be assigned a unique address on the bus.
|
||||
The default address is 128 and you should not need to change this (if you do, update the PX4 parameter [RBCLW_ADDRESS](../advanced_config/parameter_reference.md#RBCLW_ADDRESS) to match).
|
||||
|
||||
::: info
|
||||
PX4 does not support multiple RoboClaw motor controllers in the same vehicle — each controller needs a unique address on the bus, and there is only one parameter for setting the address in PX4 (`RBCLW_ADDRESS`).
|
||||
|
||||
:::
|
||||
|
||||
Then configure the actuator configuration:
|
||||
|
||||
1. Navigate to [Actuators Configuration & Testing](../config/actuators.md) in QGroundControl.
|
||||
2. Select the RoboClaw driver from the list of _Actuator Outputs_.
|
||||
|
||||
For the channel assignments, disarm, minimum, and maximum values, please refer to the image below.
|
||||
|
||||
|
||||
|
||||
For systems with more than two motors, it is possible to assign the same function to several motors.
|
||||
The reason for the unusual values, can be found in the [RoboClaw User Manual](https://downloads.basicmicro.com/docs/roboclaw_user_manual.pdf) under `Compatibility Commands` for `Packet Serial`:
|
||||
|
||||
```plain
|
||||
Drive motor forward. Valid data range is 0 - 127. A value of 127 = full speed forward, 64 =
|
||||
about half speed forward and 0 = full stop.
|
||||
```
|
||||
|
||||
## See also
|
||||
|
||||
- [roboclaw](../modules/modules_driver.md#roboclaw) driver
|
||||
- [Roboclaw User Manual](https://downloads.basicmicro.com/docs/roboclaw_user_manual.pdf)
|
||||
@@ -1,11 +0,0 @@
|
||||
# Differential Rovers
|
||||
|
||||
<Badge type="tip" text="PX4 v1.16" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
A differential rover's motion is controlled using a differential drive mechanism, where the left and right wheel speeds are adjusted independently to achieve the desired forward speed and yaw rate.
|
||||
Forward motion is achieved by driving both wheels at the same speed in the same direction.
|
||||
Rotation is achieved by driving the wheels at different speeds in opposite directions, allowing the rover to turn on the spot.
|
||||
|
||||
|
||||
|
||||
See [Configuration/Tuning](../config_rover/differential.md) to set up your rover and [Drive Modes](../flight_modes_rover/differential.md) for the supported flight (aka drive) modes.
|
||||
@@ -1,116 +0,0 @@
|
||||
# Differential-steering Rovers
|
||||
|
||||
<Badge type="tip" text="main (PX4 v1.16+)" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
:::warning
|
||||
Support for rover is [experimental](../airframes/index.md#experimental-vehicles).
|
||||
Maintainer volunteers, [contribution](../contribute/index.md) of new features, new frame configurations, or other improvements would all be very welcome!
|
||||
:::
|
||||
|
||||
A differential-steering rover's motion is controlled using a differential drive mechanism, where the left and right wheel speeds are adjusted independently to achieve the desired forward speed and yaw rate.
|
||||
|
||||
Forward motion is achieved by driving both wheels at the same speed in the same direction.
|
||||
Rotation is achieved by driving the wheels at different speeds in opposite directions, allowing the rover to turn on the spot.
|
||||
|
||||
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To start using the differential-steering rover:
|
||||
|
||||
1. Enable the module by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select the _Generic Rover Differential_:
|
||||
|
||||
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe does not show up in the UI, it can alternatively be selected by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `50000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Open the [Actuators Configuration & Testing](../config/actuators.md) to map the motor functions to flight controller outputs.
|
||||
|
||||
This is sufficient to drive the the rover in [manual mode](../flight_modes_rover/index.md#manual-mode) (see [Flight modes](../flight_modes_rover/index.md)).
|
||||
|
||||
:::info
|
||||
The parameter [RD_MAN_YAW_SCALE](../advanced_config/parameter_reference.md#RD_MAN_YAW_SCALE) can be used to scale the manual input for the yaw rate.
|
||||
:::
|
||||
|
||||
## Tuning (Basic)
|
||||
|
||||
This section goes through the basic parameters that need to be set to use all other features for the differential-steering rover.
|
||||
Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RD_WHEEL_TRACK](../advanced_config/parameter_reference.md#RD_WHEEL_TRACK) [m]: Measure the distance from the center of the right wheel to the center of the left wheel.
|
||||
|
||||
|
||||
|
||||
2. [RD_MAX_SPEED](../advanced_config/parameter_reference.md#RD_MAX_SPEED) [m/s]: In manual mode, drive the rover with full throttle and enter the observed speed as the parameter.
|
||||
|
||||
3. [RD_MAX_YAW_RATE](../advanced_config/parameter_reference.md#RD_MAX_YAW_RATE) [deg/s]: This is the maximum yaw rate you want to allow for your rover.
|
||||
This will define the stick-to-yaw-rate mapping in acro mode as well as setting an upper limit for the yaw rate in mission mode.
|
||||
|
||||
4. [RD_YAW_RATE_P](../advanced_config/parameter_reference.md#RD_YAW_RATE_P) and [RD_YAW_RATE_I](../advanced_config/parameter_reference.md#RD_YAW_RATE_I) [-]: Tuning parameters for the closed-loop yaw rate controller.
|
||||
|
||||
::: info
|
||||
This can be tuned by setting all previous parameters and then setting the rover to _acro mode_.
|
||||
Use the right stick to yaw the rover on the spot and then observe the desired and actual yaw rate in the flight log.
|
||||
Change parameters and iterate.
|
||||
|
||||
Suggestion: Start the tuning process with [RD_YAW_RATE_I](../advanced_config/parameter_reference.md#RD_YAW_RATE_I) equal to zero and only set if necessary.
|
||||
|
||||
:::
|
||||
|
||||
This is enough to start using the rover in acro mode.
|
||||
To start driving mission the parameters in [Tuning (Mission)](#tuning-mission) also must be set.
|
||||
|
||||
## Tuning (Mission)
|
||||
|
||||
:::warning
|
||||
The parameters in [Tuning (Basic)](#tuning-basic) must also be set to drive missions!
|
||||
:::
|
||||
|
||||
The module uses a control algorithm called pure pursuit, see [Mission Mode](../flight_modes_rover/index.md#mission-mode) for the basic tuning process.
|
||||
The additional parameters are separated into the following sections:
|
||||
|
||||
### Mission Velocity
|
||||
|
||||
These parameters tune velocity control in missions:
|
||||
|
||||
- [RD_MISS_SPD_DEF](#RD_MISS_SPD_DEF): Sets the default velocity ($m/s$) for the rover during the mission.
|
||||
- [RD_MAX_ACCEL](#RD_MAX_ACCEL) ($m/s^2$) and [RD_MAX_JERK](#RD_MAX_JERK) ($m/s^3$) are used to calculate a velocity trajectory such that the rover comes to a smooth stop as it reaches a waypoint.
|
||||
- [RD_SPEED_P](#RD_SPEED_P) and [RD_SPEED_I](#RD_SPEED_I) are used to tune the closed-loop velocity controller during missions.
|
||||
|
||||
### Yaw Rate
|
||||
|
||||
The yaw rate setpoint is calculated by using the heading error calculated by the pure pursuit algorithm for a PID controller that can be tuned with [RD_HEADING_P](#RD_HEADING_P) and [RD_HEADING_I](#RD_HEADING_I).
|
||||
|
||||
:::info
|
||||
There is some degree of overlap between this tuning and the pure pursuit controller gain set in [Mission Mode](../flight_modes_rover/index.md#mission-mode) as they both have an influence on how aggressive the rover will steer.
|
||||
:::
|
||||
|
||||
### State Machine
|
||||
|
||||
The module employs the following state machine to make full use of a differential-steering rovers ability to turn on the spot:
|
||||
|
||||
|
||||
These transition thresholds can be set with [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN) and [RD_TRANS_TRN_DRV](#RD_TRANS_TRN_DRV).
|
||||
|
||||
### Parameters
|
||||
|
||||
The following parameters affect the differential-steering rover in mission mode (overview):
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------- | ------- |
|
||||
| <a id="RD_MISS_SPD_DEF"></a>[RD_MISS_SPD_DEF](../advanced_config/parameter_reference.md#RD_MISS_SPD_DEF) | Mission speed for the rover | $m/s$ |
|
||||
| <a id="RD_MAX_ACCEL"></a>[RD_MAX_ACCEL](../advanced_config/parameter_reference.md#RD_MAX_ACCEL) | Maximum acceleration for the rover | $m/s^2$ |
|
||||
| <a id="RD_MAX_JERK"></a>[RD_MAX_JERK](../advanced_config/parameter_reference.md#RD_MAX_JERK) | Maximum jerk for the rover | $m/s^3$ |
|
||||
| <a id="RD_SPEED_P"></a>[RD_SPEED_P](../advanced_config/parameter_reference.md#RD_SPEED_P) | Proportional gain for speed controller | - |
|
||||
| <a id="RD_SPEED_I"></a>[RD_SPEED_I](../advanced_config/parameter_reference.md#RD_SPEED_I) | Integral gain for speed controller | * |
|
||||
| <a id="RD_HEADING_P"></a>[RD_HEADING_P](../advanced_config/parameter_reference.md#RD_HEADING_P) | Proportional gain for heading controller | - |
|
||||
| <a id="RD_HEADING_I"></a>[RD_HEADING_I](../advanced_config/parameter_reference.md#RD_HEADING_I) | Integral gain for heading controller | * |
|
||||
| <a id="RD_TRANS_DRV_TRN"></a>[RD_TRANS_DRV_TRN](../advanced_config/parameter_reference.md#RD_TRANS_DRV_TRN) | Heading error threshold to switch from driving to spot turning | deg |
|
||||
| <a id="RD_TRANS_TRN_DRV"></a>[RD_TRANS_TRN_DRV](../advanced_config/parameter_reference.md#RD_TRANS_TRN_DRV) | Heading error threshold to switch from spot turning to driving | deg |
|
||||
@@ -1,10 +0,0 @@
|
||||
# Mecanum Rovers
|
||||
|
||||
<Badge type="tip" text="PX4 v1.16" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
A Mecanum rover is a type of mobile robot that uses Mecanum wheels to achieve omnidirectional movement. These wheels are unique because they have rollers mounted at a 45-degree angle around their circumference, allowing the rover to move not only forward and backward but also side-to-side and diagonally without needing to rotate first.
|
||||
Each wheel is driven by its own motor, and by controlling the speed and direction of each motor, the rover can move in any direction or spin in place.
|
||||
|
||||
|
||||
|
||||
See [Configuration/Tuning](../config_rover/mecanum.md) to set up your rover and [Drive Modes](../flight_modes_rover/mecanum.md) for the supported flight (aka drive) modes.
|
||||
@@ -1,15 +0,0 @@
|
||||
# Buffer128 (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/Buffer128.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 len # length of data
|
||||
uint32 MAX_BUFLEN = 128
|
||||
|
||||
uint8[128] data # data
|
||||
|
||||
# TOPICS voxl2_io_data
|
||||
|
||||
```
|
||||
@@ -1,15 +0,0 @@
|
||||
# CollisionReport (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/CollisionReport.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
uint8 src
|
||||
uint32 id
|
||||
uint8 action
|
||||
uint8 threat_level
|
||||
float32 time_to_minimum_delta
|
||||
float32 altitude_minimum_delta
|
||||
float32 horizontal_minimum_delta
|
||||
|
||||
```
|
||||
@@ -1,15 +0,0 @@
|
||||
# DifferentialDriveSetpoint (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/DifferentialDriveSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 speed # [m/s] collective roll-off speed in body x-axis
|
||||
bool closed_loop_speed_control # true if speed is controlled using estimator feedback, false if direct feed-forward
|
||||
float32 yaw_rate # [rad/s] yaw rate
|
||||
bool closed_loop_yaw_rate_control # true if yaw rate is controlled using gyroscope feedback, false if direct feed-forward
|
||||
|
||||
# TOPICS differential_drive_setpoint differential_drive_control_output
|
||||
|
||||
```
|
||||
@@ -1,24 +0,0 @@
|
||||
# NpfgStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/NpfgStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 wind_est_valid # (boolean) true = wind estimate is valid and/or being used by controller (also indicates if wind est usage is disabled despite being valid)
|
||||
float32 lat_accel # resultant lateral acceleration reference [m/s^2]
|
||||
float32 lat_accel_ff # lateral acceleration demand only for maintaining curvature [m/s^2]
|
||||
float32 bearing_feas # bearing feasibility [0,1]
|
||||
float32 bearing_feas_on_track # on-track bearing feasibility [0,1]
|
||||
float32 signed_track_error # signed track error [m]
|
||||
float32 track_error_bound # track error bound [m]
|
||||
float32 airspeed_ref # (true) airspeed reference [m/s]
|
||||
float32 bearing # bearing angle [rad]
|
||||
float32 heading_ref # heading angle reference [rad]
|
||||
float32 min_ground_speed_ref # minimum forward ground speed reference [m/s]
|
||||
float32 adapted_period # adapted period (if auto-tuning enabled) [s]
|
||||
float32 p_gain # controller proportional gain [rad/s]
|
||||
float32 time_const # controller time constant [s]
|
||||
float32 can_run_factor # estimate of certainty of the correct functionality of the npfg roll setpoint in [0, 1]
|
||||
|
||||
```
|
||||
@@ -1,13 +0,0 @@
|
||||
# RoverAckermannGuidanceStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverAckermannGuidanceStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 lookahead_distance # [m] Lookahead distance of pure the pursuit controller
|
||||
float32 heading_error # [deg] Heading error of the pure pursuit controller
|
||||
|
||||
# TOPICS rover_ackermann_guidance_status
|
||||
|
||||
```
|
||||
@@ -1,16 +0,0 @@
|
||||
# RoverAckermannSetpoint (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverAckermannSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 forward_speed_setpoint # [m/s] Desired speed in body x direction. Positiv: forwards, Negativ: backwards
|
||||
float32 forward_speed_setpoint_normalized # [-1, 1] Desired normalized speed in body x direction. Positiv: forwards, Negativ: backwards
|
||||
float32 steering_setpoint # [rad] Desired steering angle
|
||||
float32 steering_setpoint_normalized # [-1, 1] Desired normalized steering angle
|
||||
float32 lateral_acceleration_setpoint # [m/s^2] Desired acceleration in body y direction. Positiv: right, Negativ: left.
|
||||
|
||||
# TOPICS rover_ackermann_setpoint
|
||||
|
||||
```
|
||||
@@ -1,18 +0,0 @@
|
||||
# RoverAckermannStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverAckermannStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 measured_forward_speed # [m/s] Measured speed in body x direction. Forwards: positiv, Backwards: negativ
|
||||
float32 adjusted_forward_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 steering_setpoint_normalized # [-1, 1] Normalized steering setpoint
|
||||
float32 adjusted_steering_setpoint_normalized # [-1, 1] Normalized steering setpoint after applying slew rate
|
||||
float32 measured_lateral_acceleration # [m/s^2] Measured acceleration in body y direction. Positiv: right, Negativ: left.
|
||||
float32 pid_throttle_integral # Integral of the PID for the closed loop speed controller
|
||||
float32 pid_lat_accel_integral # Integral of the PID for the closed loop lateral acceleration controller
|
||||
|
||||
# TOPICS rover_ackermann_status
|
||||
|
||||
```
|
||||
@@ -1,14 +0,0 @@
|
||||
# RoverDifferentialGuidanceStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverDifferentialGuidanceStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 lookahead_distance # [m] Lookahead distance of pure the pursuit controller
|
||||
float32 heading_error_deg # [deg] Heading error of the pure pursuit controller
|
||||
uint8 state_machine # Driving state of the rover [0: SPOT_TURNING, 1: DRIVING, 2: GOAL_REACHED]
|
||||
|
||||
# TOPICS rover_differential_guidance_status
|
||||
|
||||
```
|
||||
@@ -1,16 +0,0 @@
|
||||
# RoverDifferentialSetpoint (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverDifferentialSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 forward_speed_setpoint # [m/s] Desired forward speed for the rover
|
||||
float32 forward_speed_setpoint_normalized # [-1, 1] Normalized forward speed for the rover
|
||||
float32 yaw_rate_setpoint # [rad/s] Desired yaw rate for the rover (Overriden by yaw controller if yaw_setpoint is used)
|
||||
float32 speed_diff_setpoint_normalized # [-1, 1] Normalized speed difference between the left and right wheels
|
||||
float32 yaw_setpoint # [rad] Desired yaw (heading) for the rover
|
||||
|
||||
# TOPICS rover_differential_setpoint
|
||||
|
||||
```
|
||||
@@ -1,21 +0,0 @@
|
||||
# RoverDifferentialStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverDifferentialStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 measured_forward_speed # [m/s] Measured speed in body x direction. Forwards: positiv, Backwards: negativ
|
||||
float32 adjusted_forward_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 measured_yaw # [rad] Measured yaw
|
||||
float32 adjusted_yaw_setpoint # [rad] Yaw setpoint after applying slew rate
|
||||
float32 clyaw_yaw_rate_setpoint # [rad/s] Yaw rate setpoint output by the closed loop yaw controller
|
||||
float32 measured_yaw_rate # [rad/s] Measured yaw rate
|
||||
float32 adjusted_yaw_rate_setpoint # [rad/s] Yaw rate setpoint from the closed loop yaw controller
|
||||
float32 pid_yaw_integral # Integral of the PID for the closed loop yaw controller
|
||||
float32 pid_yaw_rate_integral # Integral of the PID for the closed loop yaw rate controller
|
||||
float32 pid_throttle_integral # Integral of the PID for the closed loop speed controller
|
||||
|
||||
# TOPICS rover_differential_status
|
||||
|
||||
```
|
||||
@@ -1,14 +0,0 @@
|
||||
# RoverMecanumGuidanceStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverMecanumGuidanceStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 lookahead_distance # [m] Lookahead distance of pure the pursuit controller
|
||||
float32 heading_error # [rad] Heading error of the pure pursuit controller
|
||||
float32 desired_speed # [m/s] Desired velocity magnitude (speed)
|
||||
|
||||
# TOPICS rover_mecanum_guidance_status
|
||||
|
||||
```
|
||||
@@ -1,18 +0,0 @@
|
||||
# RoverMecanumSetpoint (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverMecanumSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 forward_speed_setpoint # [m/s] Desired forward speed
|
||||
float32 forward_speed_setpoint_normalized # [-1, 1] Desired normalized forward speed
|
||||
float32 lateral_speed_setpoint # [m/s] Desired lateral speed
|
||||
float32 lateral_speed_setpoint_normalized # [-1, 1] Desired normalized lateral speed
|
||||
float32 yaw_rate_setpoint # [rad/s] Desired yaw rate
|
||||
float32 speed_diff_setpoint_normalized # [-1, 1] Normalized speed difference between the left and right wheels
|
||||
float32 yaw_setpoint # [rad] Desired yaw (heading)
|
||||
|
||||
# TOPICS rover_mecanum_setpoint
|
||||
|
||||
```
|
||||
@@ -1,24 +0,0 @@
|
||||
# RoverMecanumStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverMecanumStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 measured_forward_speed # [m/s] Measured speed in body x direction. Positiv: forwards, Negativ: backwards
|
||||
float32 adjusted_forward_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 measured_lateral_speed # [m/s] Measured speed in body y direction. Positiv: right, Negativ: left
|
||||
float32 adjusted_lateral_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 measured_yaw_rate # [rad/s] Measured yaw rate
|
||||
float32 clyaw_yaw_rate_setpoint # [rad/s] Yaw rate setpoint output by the closed loop yaw controller
|
||||
float32 adjusted_yaw_rate_setpoint # [rad/s] Yaw rate setpoint from the closed loop yaw controller
|
||||
float32 measured_yaw # [rad] Measured yaw
|
||||
float32 adjusted_yaw_setpoint # [rad] Yaw setpoint after applying slew rate
|
||||
float32 pid_yaw_rate_integral # Integral of the PID for the closed loop yaw rate controller
|
||||
float32 pid_yaw_integral # Integral of the PID for the closed loop yaw controller
|
||||
float32 pid_forward_throttle_integral # Integral of the PID for the closed loop forward speed controller
|
||||
float32 pid_lateral_throttle_integral # Integral of the PID for the closed loop lateral speed controller
|
||||
|
||||
# TOPICS rover_mecanum_status
|
||||
|
||||
```
|
||||
@@ -1,18 +0,0 @@
|
||||
# TrajectoryBezier (UORB message)
|
||||
|
||||
Bezier Trajectory description. See also Mavlink TRAJECTORY msg
|
||||
The topic trajectory_bezier describe each waypoint defined in vehicle_trajectory_bezier
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/TrajectoryBezier.msg)
|
||||
|
||||
```c
|
||||
# Bezier Trajectory description. See also Mavlink TRAJECTORY msg
|
||||
# The topic trajectory_bezier describe each waypoint defined in vehicle_trajectory_bezier
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32[3] position # local position x,y,z (metres)
|
||||
float32 yaw # yaw angle (rad)
|
||||
float32 delta # time it should take to get to this waypoint, if this is the final waypoint (seconds)
|
||||
|
||||
```
|
||||
@@ -1,23 +0,0 @@
|
||||
# TrajectoryWaypoint (UORB message)
|
||||
|
||||
Waypoint Trajectory description. See also Mavlink TRAJECTORY msg
|
||||
The topic trajectory_waypoint describe each waypoint defined in vehicle_trajectory_waypoint
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/TrajectoryWaypoint.msg)
|
||||
|
||||
```c
|
||||
# Waypoint Trajectory description. See also Mavlink TRAJECTORY msg
|
||||
# The topic trajectory_waypoint describe each waypoint defined in vehicle_trajectory_waypoint
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32[3] position
|
||||
float32[3] velocity
|
||||
float32[3] acceleration
|
||||
float32 yaw
|
||||
float32 yaw_speed
|
||||
|
||||
bool point_valid
|
||||
uint8 type
|
||||
|
||||
```
|
||||
@@ -1,29 +0,0 @@
|
||||
# VehicleTrajectoryBezier (UORB message)
|
||||
|
||||
Vehicle Waypoints Trajectory description. See also MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
The topic vehicle_trajectory_bezier is used to send a smooth flight path from the
|
||||
companion computer / avoidance module to the position controller.
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/VehicleTrajectoryBezier.msg)
|
||||
|
||||
```c
|
||||
# Vehicle Waypoints Trajectory description. See also MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
# The topic vehicle_trajectory_bezier is used to send a smooth flight path from the
|
||||
# companion computer / avoidance module to the position controller.
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 POINT_0 = 0
|
||||
uint8 POINT_1 = 1
|
||||
uint8 POINT_2 = 2
|
||||
uint8 POINT_3 = 3
|
||||
uint8 POINT_4 = 4
|
||||
|
||||
uint8 NUMBER_POINTS = 5
|
||||
|
||||
TrajectoryBezier[5] control_points
|
||||
uint8 bezier_order
|
||||
|
||||
# TOPICS vehicle_trajectory_bezier
|
||||
|
||||
```
|
||||
@@ -1,32 +0,0 @@
|
||||
# VehicleTrajectoryWaypoint (UORB message)
|
||||
|
||||
Vehicle Waypoints Trajectory description. See also MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
The topic vehicle_trajectory_waypoint_desired is used to send the user desired waypoints from the position controller to the companion computer / avoidance module.
|
||||
The topic vehicle_trajectory_waypoint is used to send the adjusted waypoints from the companion computer / avoidance module to the position controller.
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/VehicleTrajectoryWaypoint.msg)
|
||||
|
||||
```c
|
||||
# Vehicle Waypoints Trajectory description. See also MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
# The topic vehicle_trajectory_waypoint_desired is used to send the user desired waypoints from the position controller to the companion computer / avoidance module.
|
||||
# The topic vehicle_trajectory_waypoint is used to send the adjusted waypoints from the companion computer / avoidance module to the position controller.
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 MAV_TRAJECTORY_REPRESENTATION_WAYPOINTS = 0
|
||||
|
||||
uint8 type # Type from MAV_TRAJECTORY_REPRESENTATION enum.
|
||||
|
||||
uint8 POINT_0 = 0
|
||||
uint8 POINT_1 = 1
|
||||
uint8 POINT_2 = 2
|
||||
uint8 POINT_3 = 3
|
||||
uint8 POINT_4 = 4
|
||||
|
||||
uint8 NUMBER_POINTS = 5
|
||||
|
||||
TrajectoryWaypoint[5] waypoints
|
||||
|
||||
# TOPICS vehicle_trajectory_waypoint vehicle_trajectory_waypoint_desired
|
||||
|
||||
```
|
||||
@@ -1,457 +0,0 @@
|
||||
# Configuration/Tuning (Ackermann Rover)
|
||||
|
||||
This topic provides a step-by-step guide for setting up your [Ackermann rover](../frames_rover/ackermann.md).
|
||||
|
||||
Successive steps enable [drive modes](../flight_modes_rover/ackermann.md) with more autopilot support and features.
|
||||
|
||||
:::warning
|
||||
Each step is dependent on the previous steps having been completed.
|
||||
Modes will only work properly if the preceding modes have been configured.
|
||||
:::
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To configure the Ackermann rover frame and outputs:
|
||||
|
||||
1. Enable Rover support by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
Note that this is a special build that contains rover-specific modules.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select the _Generic Rover Ackermann_:
|
||||
|
||||
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe is not displayed and you have checked that you are using rover firmware (not the default), you can alternatively enable this frame by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `51000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Open the [Actuators Configuration & Testing](../config/actuators.md) to map the steering and throttle functions to flight controller outputs.
|
||||
|
||||
## Ручний режим
|
||||
|
||||
:::warning
|
||||
For this mode to work properly the [Basic Setup](#basic-setup) must've already been completed!
|
||||
:::
|
||||
|
||||
The basic setup already covers the minimum setup required to use the rover in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode).
|
||||
|
||||
This mode is also affected by (optional) acceleration/deceleration limits.
|
||||
As configuration of these limits becomes mandatory for subsequent modes, we do this setup here.
|
||||
|
||||
Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RA_WHEEL_BASE](#RA_WHEEL_BASE) [m]: Measure the distance from the back to the front wheels.
|
||||
|
||||
2. [RA_MAX_STR_ANG](#RA_MAX_STR_ANG) [deg]: Measure the maximum steering angle.
|
||||
|
||||
|
||||
|
||||
3. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: Drive the rover at full throttle and set this parameter to the observed value of the ground speed.
|
||||
|
||||
:::info
|
||||
This parameter is also used for the feed-forward term of the speed control.
|
||||
It will be further tuned in the configuration of [Position mode](#position-mode).
|
||||
|
||||
:::
|
||||
|
||||
4. (Optional) [RO_ACCEL_LIM](#RO_ACCEL_LIM) [m/s^2]: Maximum acceleration you want to allow for your rover.
|
||||
|
||||
<a id="RO_ACCEL_LIM_CONSIDERATIONS"></a>
|
||||
|
||||
:::tip
|
||||
Your rover has a maximum possible acceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. From a standstill, give the rover full throttle until it reaches the maximum speed.
|
||||
2. Disarm the rover and plot the `measured_speed_body_x` from [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md).
|
||||
3. Divide the maximum speed by the time it took to reach it and set this as the value for [RO_ACCEL_LIM](#RO_ACCEL_LIM).
|
||||
|
||||
Some RC rovers have enough torque to lift up if the maximum acceleration is not limited.
|
||||
If that is the case:
|
||||
|
||||
1. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to a low value, give the rover full throttle from a standstill and observe its behaviour.
|
||||
2. Increase [RO_ACCEL_LIM](#RO_ACCEL_LIM) until the rover starts to lift up during the acceleration.
|
||||
3. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
:::
|
||||
|
||||
5. (Optional) [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2]: Maximum deceleration you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
The same [considerations](#RO_ACCEL_LIM_CONSIDERATIONS) as in the configuration of [RO_ACCEL_LIM](#RO_ACCEL_LIM) apply.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
This parameter is also used for the calculation of the speed setpoint during [Auto modes](#auto-modes).
|
||||
|
||||
:::
|
||||
|
||||
6. (Optional) [RA_STR_RATE_LIM](#RA_STR_RATE_LIM) [deg/s]: Maximum steering rate you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
This value depends on your rover and use case.
|
||||
For bigger rovers there might be a mechanical limit that is easy to identify by steering the rover at a standstill and increasing
|
||||
[RA_STR_RATE_LIM](#RA_STR_RATE_LIM) until you observe the steering rate to no longer be limited by the parameter.
|
||||
For smaller rovers you might observe the steering to be too aggressive. Set [RA_STR_RATE_LIM](#RA_STR_RATE_LIM) to a low value and steer the rover at a standstill.
|
||||
Increase the parameter until you reach the maximum steering rate you are comfortable with.
|
||||
|
||||
:::
|
||||
|
||||
:::warning
|
||||
A low maximum steering rate makes the rover worse at tracking steering setpoints, which can lead to a poor performance in the subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
## Acro Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Manual mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
To set up [Acro mode](../flight_modes_rover/ackermann.md#acro-mode) configure the following [parameters](../advanced_config/parameters.md) in QGroundControl:
|
||||
|
||||
1. [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM): Maximum yaw rate you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
Limiting the yaw rate is necessary if the rover is prone rolling over, loosing traction at high speeds or if passenger comfort is important.
|
||||
Small rovers especially can be prone to rolling over when steering aggressively at high speeds.
|
||||
|
||||
If this is the case:
|
||||
|
||||
1. In [Acro mode](../flight_modes_rover/ackermann.md#acro-mode), set [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) to a small value and drive the rover at full throttle and with the right stick all the way to the left or right.
|
||||
2. Increase [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) until the wheels of the rover start to lift up.
|
||||
3. Set [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
If you see no need to limit the yaw rate, set this parameter to the maximum yaw rate the rover can achieve:
|
||||
|
||||
1. In [Manual mode](#manual-mode) drive the rover at full throttle and with the maximum steering angle.
|
||||
2. Plot the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and enter the highest observed value for [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM).
|
||||
|
||||
|
||||
:::
|
||||
|
||||
2. [RO_YAW_RATE_P](#RO_YAW_RATE_P) [-]: Proportional gain of the closed loop yaw rate controller.
|
||||
The closed loop acceleration control will compare the yaw rate setpoint with the measured yaw rate and adapt the motor commands based on the error between them.
|
||||
The proportional gain is multiplied with this error and that value is added to the motor command.
|
||||
This compensates for disturbances such as uneven ground and external forces.
|
||||
|
||||
:::tip
|
||||
To tune this parameter:
|
||||
|
||||
1. Put the rover in [Acro mode](../flight_modes_rover/ackermann.md#acro-mode) and hold the throttle stick and the right stick at a few different levels for a couple of seconds each.
|
||||
2. Disarm the rover and from the flight log plot the `adjusted_yaw_rate_setpoint` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
3. Increase [RO_YAW_RATE_P](#RO_YAW_RATE_P) if the measured value does not track the setpoint fast enough or decrease it if the measurement overshoots the setpoint by too much.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_YAW_RATE_I](#RO_YAW_RATE_I) [-]: Integral gain of the closed loop yaw rate controller.
|
||||
The integral gain accumulates the error between the desired and actual yaw rate scaled by the integral gain over time and that value is added to the motor command.
|
||||
|
||||
::: tip
|
||||
An integrator might not be necessary at this stage, but it will become important for subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Acro mode](../flight_modes_rover/ackermann.md#acro-mode).
|
||||
|
||||
## Stabilized Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Acro mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
For [Stabilized mode](../flight_modes_rover/differential.md#stabilized-mode) the controller utilizes a closed loop yaw controller, which creates a yaw rate setpoint to control the yaw when it is active:
|
||||
|
||||
|
||||
|
||||
Unlike the closed loop yaw rate, this controller has no feed-forward term.
|
||||
Therefore you only need to tune the closed loop gains:
|
||||
|
||||
1. [RO_YAW_P](#RO_YAW_P) [-]: Proportional gain for the closed loop yaw controller.
|
||||
|
||||
::: tip
|
||||
In stabilized mode the closed loop yaw control is only active when driving a straight line (no yaw rate input).
|
||||
To tune it start with a value of 1 for [RO_YAW_P](#RO_YAW_P).
|
||||
Put the rover into stabilized mode and move the left stick of your controller up to drive forwards.
|
||||
Disarm the rover and from the flight log plot the `measured_yaw` and the `adjusted_yaw_setpoint` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) message over each other.
|
||||
Increase/Decrease the parameter until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
For the closed loop yaw control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
Since the yaw and yaw rate controllers are cascaded, there only needs to be one integrator which is in the yaw rate controller. If you observe a steady state error in the yaw setpoint increase the [RO_YAW_RATE_I](#RO_YAW_RATE_I) parameter.
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Stabilized mode](../flight_modes_rover/ackermann.md#stabilized-mode).
|
||||
|
||||
## Position Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Stabilized mode](#stabilized-mode) must already be configured!
|
||||
:::
|
||||
|
||||
[Position mode](../flight_modes_rover/ackermann.md#position-mode) is the most advanced manual mode, utilizing closed loop yaw rate and speed control and leveraging position estimates.
|
||||
|
||||
To configure set the following parameters:
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM) [m/s]: This is the maximum speed you want to allow for your rover.
|
||||
This will define the stick-to-speed mapping for position mode and set an upper limit for the speed setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop speed control which linearly maps desired speeds to normalized motor commands.
|
||||
As mentioned in the [Manual mode](../flight_modes_rover/ackermann.md#manual-mode) configuration , a good starting point is the observed ground speed when the rover drives at maximum throttle in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode).
|
||||
|
||||
<a id="RA_SPEED_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter:
|
||||
|
||||
1. Set [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I) to zero.
|
||||
This way the speed is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and then move the left stick of your controller up and/or down and hold it at a few different levels for a couple of seconds each.
|
||||
3. Disarm the rover and from the flight log plot the `adjusted_speed_body_x_setpoint` and the `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
4. If the actual speed of the rover is higher than the speed setpoint, increase [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
::: info
|
||||
If your rover oscillates when driving a straight line in [Position mode](../flight_modes_rover/ackermann.md#position-mode), set this parameter to the observed ground speed at maximum throttle in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode) and complete steps 5-7 first before continuing the tuning of the closed loop speed control (Steps 2-4).
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_SPEED_P](#RO_SPEED_P) [-]: Proportional gain of the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RO_MAX_THR_SPEED](#RA_SPEED_TUNING).
|
||||
If you tuned [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_SPEED_I](#RO_SPEED_I) [-]: Integral gain for the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
For the closed loop speed control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
|
||||
:::
|
||||
|
||||
5. [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN): When driving in a straight line (right stick centered) position mode leverages the same path following algorithm used in [auto modes](#auto-modes) called [pure pursuit](#pure-pursuit-guidance-logic) to achieve the best possible straight line driving behaviour ([Illustration of control architecture](#pure_pursuit_controller)).
|
||||
This parameter determines how aggressive the controller will steer towards the path.
|
||||
|
||||
::: tip
|
||||
Decreasing the parameter makes it more aggressive but can lead to oscillations.
|
||||
|
||||
To tune this:
|
||||
|
||||
1. Start with a value of 1 for [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN)
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and while driving a straight line at approximately half the maximum speed observe its behaviour.
|
||||
3. If the rover does not drive in a straight line, reduce the value of the parameter, if it oscillates around the path increase the value.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
6. [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN): Minimum threshold for the lookahead distance used by the [pure pursuit algorithm](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and drive at very low speeds, if the rover starts to oscillate even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then increase the value of [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
:::
|
||||
|
||||
7. [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX): Maximum threshold for the lookahead distance used by [pure pursuit](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and drive at very high speeds, if the rover does not drive in a straight line even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then decrease the value of [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Position mode](../flight_modes_rover/ackermann.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
:::warning
|
||||
For auto modes to work properly [Manual Mode](#manual-mode), [Acro mode](#acro-mode)and [Position mode](#position-mode) must already be configured!
|
||||
:::
|
||||
|
||||
<a id="pure_pursuit_controller"></a>
|
||||
|
||||
In [auto modes](../flight_modes_rover/ackermann.md#auto-modes) the autopilot takes over navigation tasks using the following control architecture:
|
||||
|
||||
|
||||
|
||||
The required parameter configuration is discussed in the following sections.
|
||||
|
||||
### Speed
|
||||
|
||||
1. [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2] and [RO_JERK_LIM](#RO_JERK_LIM) [m/s^3] are used to calculate a speed trajectory such that the rover reaches the next waypoint with the correct [cornering speed](#cornering-speed).
|
||||
|
||||
::: tip
|
||||
Plan a mission for the rover to drive a square and observe how it slows down when approaching a waypoint:
|
||||
|
||||
- If the rover decelerates too quickly decrease the [RO_DECEL_LIM](#RO_DECEL_LIM) parameter, if it starts slowing down too early increase the parameter.
|
||||
- If you observe a jerking motion as the rover slows down, decrease the [RO_JERK_LIM](#RO_JERK_LIM) parameter otherwise increase it as much as possible as it can interfere with the tuning of [RO_DECEL_LIM](#RO_DECEL_LIM).
|
||||
|
||||
These two parameters have to be tuned as a pair, repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
2. Plot the `adjusted_speed_body_x_setpoint` and `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I).
|
||||
|
||||
### Corner Cutting
|
||||
|
||||
The module employs a special cornering logic causing the rover to "cut corners" to achieve a smooth trajectory.
|
||||
This is done by scaling the acceptance radius based on the corner the rover has to drive (for geometric explanation see [Cornering logic](#mission-cornering-logic-info-only)).
|
||||
|
||||
|
||||
|
||||
The degree to which corner cutting is allowed can be tuned, or disabled, with the following parameters:
|
||||
|
||||
:::info
|
||||
The corner cutting effect is a tradeoff between how close you get to the waypoint and the smoothness of the trajectory.
|
||||
:::
|
||||
|
||||
1. [NAV_ACC_RAD](#NAV_ACC_RAD) [m]: Default acceptance radius
|
||||
This is also used as a lower bound for the acceptance radius scaling.
|
||||
2. [RA_ACC_RAD_MAX](#RA_ACC_RAD_MAX) [m]: The maximum the acceptance radius can be scaled to.
|
||||
Set equal to [NAV_ACC_RAD](#NAV_ACC_RAD) to disable the corner cutting effect.
|
||||
3. [RA_ACC_RAD_GAIN](#RA_ACC_RAD_GAIN) [-]: This tuning parameter is a multiplicand on the [calculated ideal acceptance radius](#corner-cutting-logic) to account for dynamic effects.
|
||||
|
||||
:::tip
|
||||
Initially set this parameter to `1`.
|
||||
If you observe the rover overshooting the corner, increase this parameter until you are satisfied with the behaviour.
|
||||
Note that the scaling of the acceptance radius is limited by [RA_ACC_RAD_MAX](#RA_ACC_RAD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
### Path Following
|
||||
|
||||
The [pure pursuit](#pure-pursuit-guidance-logic) algorithm is used to calculate a yaw rate setpoint for the vehicle that is then close loop controlled.
|
||||
The close loop yaw rate was tuned in the configuration of the [Acro mode](#acro-mode), and the pure pursuit was tuned when setting up the [Position mode](#position-mode).
|
||||
During any auto navigation task observe the behaviour of the rover.
|
||||
|
||||
If you are unsatisfied with the path following, there are 2 steps to take:
|
||||
|
||||
1. Plot the `adjusted_yaw_rate_setpoint` and the `measured_yaw_rate` from the [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
2. Plot the `adjusted_yaw_setpoint` and the `measured_yaw` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the value for [RO_YAW_P](#RO_YAW_RATE_P) and potentially further tune [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
3. Steps 1 and 2 ensures accurate setpoint tracking, if the path following is still unsatisfactory you need to further tune the [pure pursuit](#pure-pursuit-guidance-logic) parameters.
|
||||
|
||||
## Pure Pursuit Guidance Logic
|
||||
|
||||
The desired yaw setpoints are generated using a pure pursuit algorithm.
|
||||
|
||||
The controller takes the intersection point between a circle around the vehicle and a line segment.
|
||||
In mission mode this line is usually constructed by connecting the previous and current waypoint.
|
||||
|
||||
|
||||
|
||||
The radius of the circle around the vehicle is used to tune the controller and is often referred to as look-ahead distance.
|
||||
|
||||
The look-ahead distance sets how aggressive the controller behaves and is defined as $l_d = v \cdot k$.
|
||||
It depends on the velocity $v$ of the rover and a tuning parameter $k$ that can be set with the parameter [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN).
|
||||
|
||||
:::info
|
||||
A lower value of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) makes the controller more aggressive but can lead to oscillations!
|
||||
:::
|
||||
|
||||
The lookahead is constrained between [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX) and [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
If the distance from the path to the rover is bigger than the lookahead distance, the rover will target the point on the path that is closest to the rover.
|
||||
|
||||
To summarize, the following parameters can be used to tune the controller:
|
||||
|
||||
| Параметр | Опис | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | ---- |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius | m |
|
||||
|
||||
## Mission Cornering Logic (Info only)
|
||||
|
||||
### Corner Cutting Logic
|
||||
|
||||
To enable a smooth trajectory, the acceptance radius of waypoints is scaled based on the angle between a line segment from the current-to-previous and current-to-next waypoints.
|
||||
The ideal trajectory would be to arrive at the next line segment with the heading pointing towards the next waypoint.
|
||||
For this purpose the minimum turning circle of the rover is inscribed tangentially to both line segments.
|
||||
|
||||
|
||||
|
||||
The acceptance radius of the waypoint is set to the distance from the waypoint to the tangential points between the circle and the line segments:
|
||||
|
||||
$$
|
||||
\begin{align*}
|
||||
r_{min} &= \frac{L}{\sin\left( \delta_{max}\right) } \\
|
||||
\theta &= \frac{1}{2}\arccos\left( \frac{\vec{a}*\vec{b}}{|\vec{a}||\vec{b}|}\right) \\
|
||||
r_{acc} &= \frac{r_{min}}{\tan\left( \theta\right) }
|
||||
\end{align*}
|
||||
$$
|
||||
|
||||
| Symbol | Опис | Unit |
|
||||
| ----------------------------------- | ---------------------------------- | ---- |
|
||||
| $\vec{a}$ | Vector from current to previous WP | m |
|
||||
| $\vec{b}$ | Vector from current to next WP | m |
|
||||
| $r_{min}$ | Minimum turn radius | m |
|
||||
| $\delta_{max}$ | Maximum steer angle | m |
|
||||
| $r_{acc}$ | Acceptance radius | m |
|
||||
|
||||
### Cornering Speed
|
||||
|
||||
To smoothen the trajectory further and reduce the risk of the rover rolling over, the rover speed is regulated as follows:
|
||||
|
||||
1. During cornering the rover drives at the following speed:
|
||||
|
||||
<!-- prettier-ignore -->
|
||||
|
||||
$$v_{cor, max} = \dot{\psi}_{max} \cdot r$$
|
||||
|
||||
with $r:$ Turning radius for the upcoming corner and $\dot{\psi}_{max}:$ Maximum yaw rate ([RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM)).
|
||||
|
||||
2. In between waypoints (straight line) the rover speed is regulated such that it will arrive at the acceptance radius of the waypoint with the desired cornering speed.
|
||||
|
||||
The rover is constrained between the maximum speed [RO_SPEED_LIM](#RO_SPEED_LIM) and the speed where the maximum steering angle does not cause the rover to exceed the yaw rate limit:
|
||||
|
||||
<!-- prettier-ignore -->
|
||||
|
||||
$$v_{min} = \frac{w_b \cdot \dot{\psi}_{max}}{tan(\delta_{max})}$$
|
||||
|
||||
with $w_b:$ Wheel base ([RA_WHEEL_BASE](#RA_WHEEL_BASE)), $\dot{\psi}_{max}:$ Maximum yaw rate ([RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM)) and $\delta_{max}:$ Maximum steering angle ([RA_MAX_STR_ANG](#RA_MAX_STR_ANG)).
|
||||
|
||||
## Огляд параметрів
|
||||
|
||||
List of all parameters of the ackermann rover module:
|
||||
|
||||
| Параметр | Опис | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------- | ------- |
|
||||
| <a id="RA_WHEEL_BASE"></a>[RA_WHEEL_BASE](../advanced_config/parameter_reference.md#RA_WHEEL_BASE) | Wheel base | m |
|
||||
| <a id="RA_MAX_STR_ANG"></a>[RA_MAX_STR_ANG](../advanced_config/parameter_reference.md#RA_MAX_STR_ANG) | Maximum steering angle | deg |
|
||||
| <a id="RO_MAX_THR_SPEED"></a>[RO_MAX_THR_SPEED](../advanced_config/parameter_reference.md#RO_MAX_THR_SPEED) | Speed the rover drives at maximum throttle | m/s |
|
||||
| <a id="RO_YAW_RATE_LIM"></a>[RO_YAW_RATE_LIM](../advanced_config/parameter_reference.md#RO_YAW_RATE_LIM) | Maximum allowed yaw rate | m/s^2 |
|
||||
| <a id="RO_YAW_RATE_P"></a>[RO_YAW_RATE_P](../advanced_config/parameter_reference.md#RO_YAW_RATE_P) | Proportional gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_RATE_I"></a>[RO_YAW_RATE_I](../advanced_config/parameter_reference.md#RO_YAW_RATE_I) | Integral gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_P"></a>[RO_YAW_P](../advanced_config/parameter_reference.md#RO_YAW_P) | Proportional gain for yaw controller | - |
|
||||
| <a id="RO_SPEED_LIM"></a>[RO_SPEED_LIM](../advanced_config/parameter_reference.md#RO_SPEED_LIM) | Maximum allowed speed | m/s |
|
||||
| <a id="RO_SPEED_P"></a>[RO_SPEED_P](../advanced_config/parameter_reference.md#RO_SPEED_P) | Proportional gain for speed controller | - |
|
||||
| <a id="RO_SPEED_I"></a>[RO_SPEED_I](../advanced_config/parameter_reference.md#RO_SPEED_I) | Integral gain for speed controller | - |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter for pure pursuit | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="NAV_ACC_RAD"></a>[NAV_ACC_RAD](../advanced_config/parameter_reference.md#NAV_ACC_RAD) | Default acceptance radius | m |
|
||||
| <a id="RA_STR_RATE_LIM"></a>[RA_STR_RATE_LIM](../advanced_config/parameter_reference.md#RA_STR_RATE_LIM) | (Optional) Maximum allowed steering rate | deg/s |
|
||||
| <a id="RO_ACCEL_LIM"></a>[RO_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_ACCEL_LIM) | (Optional) Maximum allowed acceleration | m/s^2 |
|
||||
| <a id="RO_DECEL_LIM"></a>[RO_DECEL_LIM](../advanced_config/parameter_reference.md#RO_DECEL_LIM) | (Optional) Maximum allowed deceleration | m/s^2 |
|
||||
| <a id="RO_JERK_LIM"></a>[RO_JERK_LIM](../advanced_config/parameter_reference.md#RO_JERK_LIM) | (Optional) Maximum allowed jerk | $m/s^3$ |
|
||||
| <a id="RA_ACC_RAD_MAX"></a>[RA_ACC_RAD_MAX](../advanced_config/parameter_reference.md#RA_ACC_RAD_MAX) | (Optional) Maximum radius the acceptance radius can be scaled to | m |
|
||||
| <a id="RA_ACC_RAD_GAIN"></a>[RA_ACC_RAD_GAIN](../advanced_config/parameter_reference.md#RA_ACC_RAD_GAIN) | (Optional) Tuning parameter for the acceptance radius scaling | - |
|
||||
|
||||
## Дивіться також
|
||||
|
||||
- [Drive Modes (Ackermann Rover)](../flight_modes_rover/ackermann.md).
|
||||
@@ -1,395 +0,0 @@
|
||||
# Configuration/Tuning (Differential Rover)
|
||||
|
||||
This topic provides a step-by-step guide for setting up your [Differential rover](../frames_rover/differential.md).
|
||||
Successive steps enable [drive modes](../flight_modes_rover/differential.md) with more autopilot support and features.
|
||||
|
||||
:::warning
|
||||
Each step is dependent on the previous steps having been completed.
|
||||
Modes will only work properly if the preceding modes have been configured.
|
||||
:::
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To configure the differential rover frame and outputs:
|
||||
|
||||
1. Enable Rover support by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
Note that this is a special build that contains rover-specific modules.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select _Generic Rover Differential_ frame:
|
||||
|
||||
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe is not displayed and you have checked that you are using rover firmware (not the default), you can alternatively enable this frame by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `50000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Use [Actuators Configuration & Testing](../config/actuators.md) to map the motor functions to flight controller outputs.
|
||||
|
||||
## Ручний режим
|
||||
|
||||
:::warning
|
||||
For this mode to work properly the [Basic Setup](#basic-setup) must've already been completed!
|
||||
:::
|
||||
|
||||
The basic setup already covers the minimum setup required to use the rover in [Manual mode](../flight_modes_rover/differential.md#manual-mode).
|
||||
|
||||
This mode is also affected by (optional) acceleration/deceleration limits.
|
||||
As configuration of these limits becomes mandatory for subsequent modes, we do this setup here.
|
||||
|
||||
Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RD_WHEEL_TRACK](#RD_WHEEL_TRACK) [m]: Measure the distance from the centre of the right wheel to the centre of the left wheel.
|
||||
|
||||
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: Drive the rover at full throttle and set this parameter to the observed value of the ground speed.
|
||||
|
||||
:::info
|
||||
This parameter is also used for the feed-forward term of the speed control.
|
||||
It will be further tuned in the configuration of [Position mode](#position-mode).
|
||||
|
||||
:::
|
||||
|
||||
3. (Optional) [RO_ACCEL_LIM](#RO_ACCEL_LIM) [m/s^2]: Maximum acceleration you want to allow for your rover.
|
||||
|
||||
<a id="RO_ACCEL_LIM_CONSIDERATIONS"></a>
|
||||
|
||||
:::tip
|
||||
Your rover has a maximum possible acceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. From a standstill, give the rover full throttle until it reaches the maximum speed.
|
||||
2. Disarm the rover and plot the `measured_speed_body_x` from [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md).
|
||||
3. Divide the maximum speed by the time it took to reach it and set this as the value for [RO_ACCEL_LIM](#RO_ACCEL_LIM).
|
||||
|
||||
Some RC rovers have enough torque to lift up if the maximum acceleration is not limited.
|
||||
If that is the case:
|
||||
|
||||
4. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to a low value, give the rover full throttle from a standstill and observe its behaviour.
|
||||
5. Increase [RO_ACCEL_LIM](#RO_ACCEL_LIM) until the rover starts to lift up during the acceleration.
|
||||
6. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
4. (Optional) [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2]: Maximum deceleration you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
The same [considerations](#RO_ACCEL_LIM_CONSIDERATIONS) as in the configuration of [RO_ACCEL_LIM](#RO_ACCEL_LIM) apply.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
This parameter is also used for the calculation of the speed setpoint during [Auto modes](#auto-modes).
|
||||
|
||||
:::
|
||||
|
||||
## Acro Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Manual mode](#manual-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
To set up [Acro mode](../flight_modes_rover/differential.md#acro-mode), navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) [deg/s]: This is the maximum yaw rate you want to allow for your rover.
|
||||
This will define the stick-to-yaw-rate mapping for all manual modes using closed loop yaw control and set an upper limit for the yaw rate setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RD_MAX_THR_YAW_R](#RD_MAX_THR_YAW_R) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop yaw rate control.
|
||||
The controller calculates the required speed difference between the left and right motor to achieve the desired yaw rate.
|
||||
This desired speed difference is then linearly mapped to normalized motor commands.
|
||||
To get a good starting value for this parameter drive the rover in manual mode forwards at full throttle and note the ground speed of the vehicle.
|
||||
Then enter _half_ this value for the parameter. <a id="RD_YAW_RATE_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter, first make sure you set [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I) to zero.
|
||||
This way the yaw rate is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
Now put the rover in [Acro mode](../flight_modes_rover/differential.md#acro-mode) and then move the right-stick of your controller to the right and/or left and hold it at a few different levels for a couple of seconds each.
|
||||
Disarm the rover and from the flight log plot the `adjusted_yaw_rate_setpoint` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the actual yaw rate of the rover is higher than the yaw rate setpoint, increase [RD_MAX_THR_YAW_R](#RD_MAX_THR_YAW_R).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_YAW_RATE_P](#RO_YAW_RATE_P) [-]: Proportional gain of the closed loop yaw rate controller.
|
||||
Unlike the feed-forward part of the controller, the closed loop yaw rate control will compare the yaw rate setpoint with the measured yaw rate and adapt to motor commands based on the error between them.
|
||||
The proportional gain is multiplied with this error and that value is added to the motor command.
|
||||
This compensates for disturbances such as uneven ground and external forces.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RD_MAX_THR_YAW_R](#RD_YAW_RATE_P_TUNING).
|
||||
If you tuned [RD_MAX_THR_YAW_R](#RD_MAX_THR_YAW_R) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_YAW_RATE_I](#RO_YAW_RATE_I) [-]: Integral gain of the closed loop yaw controller.
|
||||
The integral gain accumulates the error between the desired and actual yaw rate scaled by the integral gain over time and that value is added to the motor command.
|
||||
|
||||
::: tip
|
||||
An integrator might not be neccessary at this stage, but it will become important for subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
5. (Optional) [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM) and [RO_YAW_DECEL_LIM](#RO_YAW_DECEL_LIM) [deg/s^2]:
|
||||
This is the maximum yaw acceleration and deceleration you want to allow for your rover.
|
||||
This can be used to smooth the `yaw_rate` setpoints and make their trajectory feasible based on the physical limitations of the rover.
|
||||
It also improves tracking and avoid integrator build up.
|
||||
|
||||
::: tip
|
||||
Your rover has a maximum possible yaw acceleration/deceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. Put the rover into [Manual mode](../flight_modes_rover/differential.md#manual-mode).
|
||||
2. From a standstill, move the right stick all the way to the right or left until the rover reaches the maximum yaw rate then return the right stick to the middle.
|
||||
3. Disarm the rover and plot the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md).
|
||||
4. Divide the maximum yaw rate by the time it took to reach it and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
5. Divide the maximum yaw rate by the time it took to return to a standstill and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Acro mode](../flight_modes_rover/differential.md#acro-mode).
|
||||
|
||||
## Stabilized Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Acro mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
For [Stabilized mode](../flight_modes_rover/differential.md#stabilized-mode) the controller utilizes a closed loop yaw controller, which creates a yaw rate setpoint to control the yaw when it is active:
|
||||
|
||||
|
||||
|
||||
Unlike the closed loop yaw rate, this controller has no feed-forward term.
|
||||
Therefore you only need to tune the closed loop gains:
|
||||
|
||||
1. [RO_YAW_P](#RO_YAW_P) [-]: Proportional gain for the closed loop yaw controller.
|
||||
|
||||
::: tip
|
||||
In stabilized mode the closed loop yaw control is only active when driving a straight line (no yaw rate input).
|
||||
|
||||
1. Start with a value of 1 for [RO_YAW_P](#RO_YAW_P).
|
||||
2. Put the rover into stabilized mode and move the left stick of your controller up and/or down to drive forwards/backwards.
|
||||
3. Disarm the rover and from the flight log plot the `measured_yaw` and the `adjusted_yaw_setpoint` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) message over each other.
|
||||
4. Increase/Decrease the parameter until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
For the closed loop yaw control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
Since the yaw and yaw rate controllers are cascaded, there only needs to be one integrator which is in the yaw rate controller.
|
||||
If you observe a steady state error in the yaw setpoint increase the [RO_YAW_RATE_I](#RO_YAW_RATE_I) parameter.
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Stabilized mode](../flight_modes_rover/differential.md#stabilized-mode).
|
||||
|
||||
## Position Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Stabilized mode](#stabilized-mode) must already be configured!
|
||||
:::
|
||||
|
||||
[Position mode](../flight_modes_rover/differential.md#position-mode) is the most advanced manual mode, utilizing closed loop yaw rate, yaw and speed control and leveraging position estimates.
|
||||
|
||||
To configure set the following parameters:
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM) [m/s]: This is the maximum speed you want to allow for your rover.
|
||||
This will define the stick-to-speed mapping for position mode and set an upper limit for the speed setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop speed control which linearly maps desired speeds to normalized motor commands.
|
||||
A good starting point is the observed ground speed when the rover drives at maximum throttle in [Manual mode](../flight_modes_rover/differential.md#manual-mode).
|
||||
|
||||
<a id="RD_SPEED_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter:
|
||||
|
||||
1. Set [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I) to zero.
|
||||
This way the speed is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and then move the left stick of your controller up and/or down and hold it at a few different levels for a couple of seconds each.
|
||||
3. Disarm the rover and from the flight log plot the `adjusted_speed_body_x_setpoint` and the `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
4. If the actual speed of the rover is higher than the speed setpoint, increase [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
::: info
|
||||
If your rover oscillates when driving a straight line in [Position mode](../flight_modes_rover/differential.md#position-mode) just set this parameter to the observed ground speed at maximum throttle in [Manual mode](../flight_modes_rover/differential.md#manual-mode) and complete steps 5-7 first before continuing the tuning of the closed loop speed control (Steps 2-4).
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_SPEED_P](#RO_SPEED_P) [-]: Proportional gain of the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RO_MAX_THR_SPEED](#RD_SPEED_P_TUNING).
|
||||
If you tuned [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_SPEED_I](#RO_SPEED_I) [-]: Integral gain for the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
For the closed loop speed control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
|
||||
:::
|
||||
|
||||
5. [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN): When driving in a straight line (no yaw rate input) position mode leverages the same path following algorithm used in [auto modes](#auto-modes) called [pure pursuit](#pure-pursuit-guidance-logic) to achieve the best possible straight line driving behaviour ([Illustration of control architecture](#pure_pursuit_controller)).
|
||||
This parameter determines how aggressive the controller will steer towards the path.
|
||||
|
||||
::: tip
|
||||
Decreasing the parameter makes it more aggressive but can lead to oscillations.
|
||||
|
||||
To tune this:
|
||||
|
||||
1. Start with a value of 1 for [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN)
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and while driving a straight line at approximately half the maximum speed observe its behaviour.
|
||||
3. If the rover does not drive in a straight line, reduce the value of the parameter, if it oscillates around the path increase the value.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
6. [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN): Minimum threshold for the lookahead distance used by the [pure pursuit algorithm](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and drive at very low speeds, if the rover starts to oscillate even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then increase the value of [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
:::
|
||||
|
||||
7. [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX): Maximum threshold for the lookahead distance used by [pure pursuit](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and drive at very high speeds, if the rover does not drive in a straight line even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then decrease the value of [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Position mode](../flight_modes_rover/differential.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Position mode](#position-mode) must already be configured!
|
||||
:::
|
||||
|
||||
<a id="pure_pursuit_controller"></a>
|
||||
In [auto modes](../flight_modes_rover/differential.md#auto-modes) the autopilot takes over navigation tasks using the following control architecture:
|
||||
|
||||
|
||||
|
||||
The required parameters are separated into the following sections:
|
||||
|
||||
### Speed
|
||||
|
||||
These parameters are used to calculate the speed setpoint in auto modes:
|
||||
|
||||
1. [RO_DECEL_LIM](#RO_DECEL_LIM) ($m/s^2$) and [RO_JERK_LIM](#RO_JERK_LIM) ($m/s^3$) are used to calculate a velocity trajectory such that the rover comes to a smooth stop as it reaches a waypoint.
|
||||
|
||||
::: tip
|
||||
Plan a mission for the rover to drive a square and observe how it slows down when approaching a waypoint:
|
||||
|
||||
- If the rover decelerates too quickly decrease the [RO_DECEL_LIM](#RO_DECEL_LIM) parameter, if it starts slowing down too early increase the parameter.
|
||||
- If you observe a jerking motion as the rover slows down, decrease the [RO_JERK_LIM](#RO_JERK_LIM) parameter otherwise increase it as much as possible as it can interfere with the tuning of [RO_DECEL_LIM](#RO_DECEL_LIM).
|
||||
|
||||
These two parameters have to be tuned as a pair, repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
2. Plot the `adjusted_speed_body_x_setpoint` and `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I).
|
||||
|
||||
The rover only slows down when approaching the waypoint if the angle between the line segment between the previous/current waypoint and current/next waypoint is smaller than 180° - [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN).
|
||||
In other words: The rover slows down only if the expected heading error towards the next waypoint when arriving at the current waypoint is below [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN).
|
||||
|
||||
|
||||
|
||||
For more information on the [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN) parameter see [State Machine](#state-machine).
|
||||
|
||||
### State Machine
|
||||
|
||||
The module employs the following state machine to make full use of a differential rovers ability to turn on the spot:
|
||||
|
||||
|
||||
|
||||
These transition thresholds can be set with [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN) and [RD_TRANS_TRN_DRV](#RD_TRANS_TRN_DRV).
|
||||
|
||||
### Path Following
|
||||
|
||||
The [pure pursuit](#pure-pursuit-guidance-logic) algorithm is used to calculate a desired yaw for the vehicle that is then close loop controlled.
|
||||
The close loop yaw rate was tuned in the configuration of the [Stabilized mode](#stabilized-mode) and the pure pursuit was tuned when setting up the [Position mode](#position-mode).
|
||||
During any auto navigation task observe the behaviour of the rover.
|
||||
If you are unsatisfied with the path following, there are 3 steps to take:
|
||||
|
||||
1. Plot the `adjusted_yaw_rate_setpoint` and the `measured_yaw_rate` from the [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
2. Plot the `adjusted_yaw_setpoint` and the `measured_yaw` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the value for [RO_YAW_P](#RO_YAW_RATE_P) and potentially further tune [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
3. Steps 1 and 2 ensures accurate setpoint tracking, if the path following is still unsatisfactory you need to further tune the [pure pursuit](#pure-pursuit-guidance-logic) parameters.
|
||||
|
||||
## Pure Pursuit Guidance Logic
|
||||
|
||||
The desired yaw setpoints are generated using a pure pursuit algorithm:
|
||||
The controller takes the intersection point between a circle around the vehicle and a line segment.
|
||||
In mission mode this line is usually constructed by connecting the previous and current waypoint:
|
||||
|
||||
|
||||
|
||||
The radius of the circle around the vehicle is used to tune the controller and is often referred to as look-ahead distance.
|
||||
|
||||
The look ahead distance sets how aggressive the controller behaves and is defined as $l_d = v \cdot k$.
|
||||
It depends on the velocity $v$ of the rover and a tuning parameter $k$ that can be set with the parameter [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN).
|
||||
|
||||
:::info
|
||||
A lower value of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) makes the controller more aggressive but can lead to oscillations!
|
||||
:::
|
||||
|
||||
The lookahead is constrained between [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX) and [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
If the distance from the path to the rover is bigger than the lookahead distance, the rover will target the point on the path that is closest to the rover.
|
||||
|
||||
To summarize, the following parameters can be used to tune the controller:
|
||||
|
||||
| Параметр | Опис | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | ---- |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius | m |
|
||||
|
||||
## Огляд параметрів
|
||||
|
||||
List of all parameters of the differential rover module:
|
||||
|
||||
| Параметр | Опис | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- | ------- |
|
||||
| <a id="RD_WHEEL_TRACK"></a>[RD_WHEEL_TRACK](../advanced_config/parameter_reference.md#RD_WHEEL_TRACK) | Wheel track | m |
|
||||
| <a id="RD_MAX_THR_YAW_R"></a>[RD_MAX_THR_YAW_R](../advanced_config/parameter_reference.md#RD_MAX_THR_YAW_R) | Yaw rate turning left/right wheels at max speed in opposite directions | m/s |
|
||||
| <a id="RD_TRANS_DRV_TRN"></a>[RD_TRANS_DRV_TRN](../advanced_config/parameter_reference.md#RD_TRANS_DRV_TRN) | Heading error threshold to switch from driving to spot turning | deg |
|
||||
| <a id="RD_TRANS_TRN_DRV"></a>[RD_TRANS_TRN_DRV](../advanced_config/parameter_reference.md#RD_TRANS_TRN_DRV) | Heading error threshold to switch from spot turning to driving | deg |
|
||||
| <a id="RD_MISS_SPD_GAIN"></a>[RD_MISS_SPD_GAIN](../advanced_config/parameter_reference.md#RD_MISS_SPD_GAIN) | Tuning parameter for the speed reduction during waypoint transition | m/s |
|
||||
| <a id="RO_YAW_RATE_LIM"></a>[RO_YAW_RATE_LIM](../advanced_config/parameter_reference.md#RO_YAW_RATE_LIM) | Maximum allowed yaw rate for the rover | deg/s |
|
||||
| <a id="RO_YAW_RATE_P"></a>[RO_YAW_RATE_P](../advanced_config/parameter_reference.md#RO_YAW_RATE_P) | Proportional gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_RATE_I"></a>[RO_YAW_RATE_I](../advanced_config/parameter_reference.md#RO_YAW_RATE_I) | Integral gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_P"></a>[RO_YAW_P](../advanced_config/parameter_reference.md#RO_YAW_P) | Proportional gain for yaw controller | - |
|
||||
| <a id="RO_MAX_THR_SPEED"></a>[RO_MAX_THR_SPEED](../advanced_config/parameter_reference.md#RO_MAX_THR_SPEED) | Speed the rover drives at maximum throttle | m/s |
|
||||
| <a id="RO_SPEED_P"></a>[RO_SPEED_P](../advanced_config/parameter_reference.md#RO_SPEED_P) | Proportional gain for speed controller | - |
|
||||
| <a id="RO_SPEED_I"></a>[RO_SPEED_I](../advanced_config/parameter_reference.md#RO_SPEED_I) | Integral gain for speed controller | - |
|
||||
| <a id="RO_SPEED_LIM"></a>[RO_SPEED_LIM](../advanced_config/parameter_reference.md#RO_SPEED_LIM) | Maximum allowed speed for the rover (and default mission speed). | m/s |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter for pure pursuit | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="RO_ACCEL_LIM"></a>[RO_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_ACCEL_LIM) | (Optional) Maximum allowed acceleration | m/s^2 |
|
||||
| <a id="RO_DECEL_LIM"></a>[RO_DECEL_LIM](../advanced_config/parameter_reference.md#RO_DECEL_LIM) | (Optional) Maximum allowed deceleration | m/s^2 |
|
||||
| <a id="RO_JERK_LIM"></a>[RO_JERK_LIM](../advanced_config/parameter_reference.md#RO_JERK_LIM) | (Optional) Maximum allowed jerk | $m/s^3$ |
|
||||
| <a id="RO_YAW_ACCEL_LIM"></a>[RO_YAW_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_ACCEL_LIM) | (Optional) Maximum allowed yaw acceleration | m/s^2 |
|
||||
| <a id="RO_YAW_DECEL_LIM"></a>[RO_YAW_DECEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_DECEL_LIM) | (Optional) Maximum allowed yaw deceleration | m/s^2 |
|
||||
|
||||
## Дивіться також
|
||||
|
||||
- [Drive Modes (Differential Rover)](../flight_modes_rover/differential.md).
|
||||
@@ -1,396 +0,0 @@
|
||||
# Configuration/Tuning (Mecanum Rover)
|
||||
|
||||
This topic provides a step-by-step guide for setting up your [Mecanum rover](../frames_rover/mecanum.md).
|
||||
Successive steps enable [drive modes](../flight_modes_rover/mecanum.md) with more autopilot support and features.
|
||||
|
||||
:::warning
|
||||
Each step is dependent on the previous steps having been completed.
|
||||
Modes will only work properly if the preceding modes have been configured.
|
||||
:::
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To start using the mecanum rover:
|
||||
|
||||
1. Enable Rover support by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
Note that this is a special build that contains rover-specific modules.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select _Generic Rover Mecanum_ frame:
|
||||
|
||||
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe does not show up in the UI, it can alternatively be selected by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `52000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Use [Actuators Configuration & Testing](../config/actuators.md) to map the motor functions to flight controller outputs.
|
||||
|
||||
## Ручний режим
|
||||
|
||||
:::warning
|
||||
For this mode to work properly the [Basic Setup](#basic-setup) must've already been completed!
|
||||
:::
|
||||
|
||||
The basic setup already covers the minimum setup required to use the rover in [Manual mode](../flight_modes_rover/mecanum.md#manual-mode).
|
||||
|
||||
This mode is also affected by (optional) acceleration/deceleration limits.
|
||||
As configuration of these limits becomes mandatory for subsequent modes, we do this setup here.
|
||||
|
||||
Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RM_WHEEL_TRACK](#RM_WHEEL_TRACK) [m]: Measure the distance from the centre of the right wheel to the centre of the left wheel.
|
||||
|
||||
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: Drive the rover at full throttle and set this parameter to the observed value of the ground speed.
|
||||
|
||||
:::info
|
||||
This parameter is also used for the feed-forward term of the speed control.
|
||||
It will be further tuned in the configuration of [Position mode](#position-mode).
|
||||
|
||||
:::
|
||||
|
||||
3. (Optional) [RO_ACCEL_LIM](#RO_ACCEL_LIM) [m/s^2]: Maximum acceleration you want to allow for your rover.
|
||||
|
||||
<a id="RO_ACCEL_LIM_CONSIDERATIONS"></a>
|
||||
|
||||
:::tip
|
||||
Your rover has a maximum possible acceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. From a standstill, give the rover full throttle until it reaches the maximum speed.
|
||||
2. Disarm the rover and plot the `measured_speed_body_x` from [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md).
|
||||
3. Divide the maximum speed by the time it took to reach it and set this as the value for [RO_ACCEL_LIM](#RO_ACCEL_LIM).
|
||||
|
||||
Some RC rovers have enough torque to lift up if the maximum acceleration is not limited.
|
||||
If that is the case:
|
||||
|
||||
4. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to a low value, give the rover full throttle from a standstill and observe its behaviour.
|
||||
5. Increase [RO_ACCEL_LIM](#RO_ACCEL_LIM) until the rover starts to lift up during the acceleration.
|
||||
6. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
4. (Optional) [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2]: Maximum deceleration you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
The same [considerations](#RO_ACCEL_LIM_CONSIDERATIONS) as in the configuration of [RO_ACCEL_LIM](#RO_ACCEL_LIM) apply.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
This parameter is also used for the calculation of the speed setpoint during [Auto modes](#auto-modes).
|
||||
|
||||
:::
|
||||
|
||||
## Acro Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Manual mode](#manual-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
To set up [Acro mode](../flight_modes_rover/mecanum.md#acro-mode) navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) [deg/s]: This is the maximum yaw rate you want to allow for your rover.
|
||||
This will define the stick-to-yaw-rate mapping for all manual modes using closed loop yaw control and set an upper limit for the yaw rate setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RM_MAX_THR_YAW_R](#RM_MAX_THR_YAW_R) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop yaw rate control.
|
||||
The controller calculates the required speed difference between the left and right motor to achieve the desired yaw rate.
|
||||
This desired speed difference is then linearly mapped to normalized motor commands.
|
||||
To get a good starting value for this parameter drive the rover in manual mode forwards at full throttle and note the ground speed of the vehicle.
|
||||
Then enter _half_ this value for the parameter. <a id="RM_YAW_RATE_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter, first make sure you set [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I) to zero.
|
||||
This way the yaw rate is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
Now put the rover in [Acro mode](../flight_modes_rover/mecanum.md#acro-mode) and then move the right-stick of your controller to the right and/or left and hold it at a few different levels for a couple of seconds each.
|
||||
Disarm the rover and from the flight log plot the `adjusted_yaw_rate_setpoint` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the actual yaw rate of the rover is higher than the yaw rate setpoint, increase [RM_MAX_THR_YAW_R](#RM_MAX_THR_YAW_R).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_YAW_RATE_P](#RO_YAW_RATE_P) [-]: Proportional gain of the closed loop yaw rate controller.
|
||||
Unlike the feed-forward part of the controller, the closed loop yaw rate control will compare the yaw rate setpoint with the measured yaw rate and adapt to motor commands based on the error between them.
|
||||
The proportional gain is multiplied with this error and that value is added to the motor command.
|
||||
This compensates for disturbances such as uneven ground and external forces.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RM_MAX_THR_YAW_R](#RM_YAW_RATE_P_TUNING).
|
||||
If you tuned [RM_MAX_THR_YAW_R](#RM_MAX_THR_YAW_R) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_YAW_RATE_I](#RO_YAW_RATE_I) [-]: Integral gain of the closed loop yaw controller.
|
||||
The integral gain accumulates the error between the desired and actual yaw rate scaled by the integral gain over time and that value is added to the motor command.
|
||||
|
||||
::: tip
|
||||
An integrator might not be neccessary at this stage, but it will become important for subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
5. (Optional) [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM) and [RO_YAW_DECEL_LIM](#RO_YAW_DECEL_LIM) [deg/s^2]: This is the maximum yaw acceleration and deceleration you want to allow for your rover.
|
||||
This can be used to smooth the `yaw_rate` setpoints and make their trajectory feasible based on the physical limitation on the rover to improve tracking and avoid integrator build up.
|
||||
|
||||
::: tip
|
||||
Your rover has a maximum possible yaw acceleration/deceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. Put the rover into [Manual mode](../flight_modes_rover/mecanum.md#manual-mode).
|
||||
2. From a standstill, move the right stick all the way to the right or left until the rover reaches the maximum yaw rate then return the right stick to the middle.
|
||||
3. Disarm the rover and plot the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md).
|
||||
4. Divide the maximum yaw rate by the time it took to reach it and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
5. Divide the maximum yaw rate by the time it took to return to a standstill and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Acro mode](../flight_modes_rover/mecanum.md#acro-mode).
|
||||
|
||||
## Stabilized Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Acro mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
For [Stabilized mode](../flight_modes_rover/mecanum.md#stabilized-mode) the controller utilizes a closed loop yaw controller, which creates a yaw rate setpoint to control the yaw when it is active:
|
||||
|
||||
|
||||
|
||||
Unlike the closed loop yaw rate, this controller has no feed-forward term.
|
||||
Therefore you only need to tune the closed loop gains:
|
||||
|
||||
1. [RO_YAW_P](#RO_YAW_P) [-]: Proportional gain for the closed loop yaw controller.
|
||||
|
||||
::: tip
|
||||
In stabilized mode the closed loop yaw control is only active when driving a straight line (no yaw rate input).
|
||||
Start with a value of 1 for [RO_YAW_P](#RO_YAW_P).
|
||||
Put the rover into stabilized mode and move the left stick of your controller up and/or down to drive forwards/backwards.
|
||||
Disarm the rover and from the flight log plot the `measured_yaw` and the `adjusted_yaw_setpoint` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) message over each other.
|
||||
Increase/Decrease the parameter until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
For the closed loop yaw control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
Since the yaw and yaw rate controllers are cascaded, there only needs to be one integrator which is in the yaw rate controller.
|
||||
If you observe a steady state error in the yaw setpoint increase the [RO_YAW_RATE_I](#RO_YAW_RATE_I) parameter.
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Stabilized mode](../flight_modes_rover/mecanum.md#stabilized-mode).
|
||||
|
||||
## Position Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Stabilized mode](#stabilized-mode) must already be configured!
|
||||
:::
|
||||
|
||||
[Position mode](../flight_modes_rover/mecanum.md#position-mode) is the most advanced manual mode, utilizing closed loop yaw rate, yaw and speed control and leveraging position estimates.
|
||||
|
||||
To configure set the following parameters:
|
||||
|
||||
:::info
|
||||
The speed control in longitudinal and lateral direction use the same tuning parameters.
|
||||
:::
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM) [m/s]: This is the maximum speed you want to allow for your rover.
|
||||
This will define the stick-to-speed mapping for position mode and set an upper limit for the speed setpoint for all [auto modes](#auto-modes).
|
||||
For mecanum rovers the speed is defined in the direction of travel (magnitude of the velocity vector consisting of the longitudinal and lateral speed).
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop speed control which linearly maps desired speeds to normalized motor commands.
|
||||
A good starting point is the observed ground speed when the rover drives at maximum throttle in [Manual mode](../flight_modes_rover/mecanum.md#manual-mode).
|
||||
|
||||
<a id="RD_SPEED_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter:
|
||||
|
||||
1. Set [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I) to zero.
|
||||
This way the speed is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and then move the left stick of your controller up and/or down and hold it at a few different levels for a couple of seconds each.
|
||||
3. Disarm the rover and from the flight log plot the `adjusted_speed_body_x_setpoint` and the `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
4. If the actual speed of the rover is higher than the speed setpoint, increase [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
::: info
|
||||
If your rover oscillates when driving a straight line in [Position mode](../flight_modes_rover/mecanum.md#position-mode) just set this parameter to the observed ground speed at maximum throttle in [Manual mode](../flight_modes_rover/mecanum.md#manual-mode) and complete steps 5-7 first before continuing the tuning of the closed loop speed control (Steps 2-4).
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_SPEED_P](#RO_SPEED_P) [-]: Proportional gain of the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RO_MAX_THR_SPEED](#RD_SPEED_P_TUNING).
|
||||
If you tuned [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_SPEED_I](#RO_SPEED_I) [-]: Integral gain for the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
For the closed loop speed control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
|
||||
:::
|
||||
|
||||
5. [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN): When driving in a straight line (no yaw rate input) position mode leverages the same path following algorithm used in [auto modes](#auto-modes) called [pure pursuit](#pure-pursuit-guidance-logic) to achieve the best possible straight line driving behaviour ([Illustration of control architecture](#pure_pursuit_controller)).
|
||||
This parameter determines how aggressive the controller will steer towards the path.
|
||||
|
||||
::: tip
|
||||
Decreasing the parameter makes it more aggressive but can lead to oscillations.
|
||||
|
||||
To tune this:
|
||||
|
||||
1. Start with a value of 1 for [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN)
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and while driving a straight line at approximately half the maximum speed observe its behaviour.
|
||||
3. If the rover does not drive in a straight line, reduce the value of the parameter, if it oscillates around the path increase the value.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
6. [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN): Minimum threshold for the lookahead distance used by the [pure pursuit algorithm](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and drive at very low speeds, if the rover starts to oscillate even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then increase the value of [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
:::
|
||||
|
||||
7. [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX): Maximum threshold for the lookahead distance used by [pure pursuit](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and drive at very high speeds, if the rover does not drive in a straight line even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then decrease the value of [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Position mode](../flight_modes_rover/mecanum.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Position mode](#position-mode) must already be configured!
|
||||
:::
|
||||
|
||||
<a id="pure_pursuit_controller"></a>
|
||||
In [auto modes](../flight_modes_rover/mecanum.md#auto-modes) the autopilot takes over navigation tasks using the following control architecture:
|
||||
|
||||
|
||||
|
||||
The mecanum module fully leverages the omnidirectionality of this type of rover by maintaining the initial heading of the rover during the entire mission (see [Pure Pursuit Guidance Logic](#pure-pursuit-guidance-logic)).
|
||||
|
||||
The required parameters are separated into the following sections:
|
||||
|
||||
### Speed
|
||||
|
||||
These parameters are used to calculate the velocity setpoint in auto modes:
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM): Sets the default speed ($m/s$) for the rover during the mission (as well as the maximum speed).
|
||||
For mecanum rovers the speed is defined in the direction of travel (magnitude of the velocity vector consisting of the longitudinal and lateral speed).
|
||||
|
||||
2. [RO_DECEL_LIM](#RO_DECEL_LIM) ($m/s^2$) and [RO_JERK_LIM](#RO_JERK_LIM) ($m/s^3$) are used to calculate a velocity trajectory such that the rover comes to a smooth stop as it reaches a waypoint.
|
||||
|
||||
::: tip
|
||||
Plan a mission for the rover to drive a square and observe how it slows down when approaching a waypoint:
|
||||
|
||||
- If the rover decelerates too quickly decrease the [RO_DECEL_LIM](#RO_DECEL_LIM) parameter, if it starts slowing down too early increase the parameter.
|
||||
- If you observe a jerking motion as the rover slows down, decrease the [RO_JERK_LIM](#RO_JERK_LIM) parameter otherwise increase it as much as possible as it can interfere with the tuning of [RO_DECEL_LIM](#RO_DECEL_LIM).
|
||||
|
||||
These two parameters have to be tuned as a pair, repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
3. [RM_MISS_SPD_GAIN](#RM_MISS_SPD_GAIN): The rover slows down when approaching a waypoint based on the angle between the line segment from the previous to current waypoint and current to next waypoint.
|
||||
How much the rover slows down can be tuned with this parameter:
|
||||
|
||||
$$
|
||||
v_{transition} = v_{max} \cdot (1 - \theta_{normalized} * k)
|
||||
$$
|
||||
|
||||
with:
|
||||
|
||||
- $v_{transition}:$ Transition speed
|
||||
- $v_{max}:$ Maximum speed ([RO_SPEED_LIM](#RO_SPEED_LIM))
|
||||
- $\theta_{normalized}:$ Angle between the line segment of the prev-current and current-next waypoints, normalized from $[0\degree, 180\degree]$ to $[0, 1]$
|
||||
- $k:$ Tuning parameter ([RM_MISS_SPD_GAIN](#RM_MISS_SPD_GAIN)).
|
||||
|
||||
4. Plot the `adjusted_speed_body_x_setpoint` and `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I).
|
||||
|
||||
### Path Following
|
||||
|
||||
The [pure pursuit](#pure-pursuit-guidance-logic) algorithm is used to calculate a desired bearing for the vehicle that is then close loop controlled.
|
||||
For mecanum rovers the path following is achieved by directly controlling the velocity of the rover in direction of the desired bearing.
|
||||
During any auto navigation task observe the behaviour of the rover:
|
||||
|
||||
1. If you are unsatisfied with the path following you need to further tune the [pure pursuit](#pure-pursuit-guidance-logic) parameters.
|
||||
2. If the rover does not maintain its initial heading well enough, adjust the value for [RO_YAW_P](#RO_YAW_RATE_P) and potentially further tune [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
|
||||
## Pure Pursuit Guidance Logic
|
||||
|
||||
The desired bearing setpoints are generated using a pure pursuit algorithm:
|
||||
The controller takes the intersection point between a circle around the vehicle and a line segment.
|
||||
In mission mode this line is usually constructed by connecting the previous and current waypoint:
|
||||
|
||||
|
||||
|
||||
The radius of the circle around the vehicle is used to tune the controller and is often referred to as look-ahead distance.
|
||||
|
||||
The look ahead distance sets how aggressive the controller behaves and is defined as $l_d = v \cdot k$.
|
||||
It depends on the velocity $v$ of the rover and a tuning parameter $k$ that can be set with the parameter [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN).
|
||||
|
||||
:::info
|
||||
A lower value of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) makes the controller more aggressive but can lead to oscillations!
|
||||
:::
|
||||
|
||||
The lookahead is constrained between [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX) and [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
If the distance from the path to the rover is bigger than the lookahead distance, the rover will target the point on the path that is closest to the rover.
|
||||
|
||||
To summarize, the following parameters can be used to tune the controller:
|
||||
|
||||
| Параметр | Опис | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | ---- |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius | m |
|
||||
|
||||
## Огляд параметрів
|
||||
|
||||
List of all parameters of the mecanum rover module:
|
||||
|
||||
| Параметр | Опис | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- | ------- |
|
||||
| <a id="RM_WHEEL_TRACK"></a>[RM_WHEEL_TRACK](../advanced_config/parameter_reference.md#RM_WHEEL_TRACK) | Wheel track | m |
|
||||
| <a id="RM_MAX_THR_YAW_R"></a>[RM_MAX_THR_YAW_R](../advanced_config/parameter_reference.md#RM_MAX_THR_YAW_R) | Yaw rate turning left/right wheels at max speed in opposite directions | m/s |
|
||||
| <a id="RM_MISS_SPD_GAIN"></a>[RM_MISS_SPD_GAIN](../advanced_config/parameter_reference.md#RM_MISS_SPD_GAIN) | Tuning parameter for the velocity reduction during waypoint transition | - |
|
||||
| <a id="RM_COURSE_CTL_TH"></a>[RM_COURSE_CTL_TH](../advanced_config/parameter_reference.md#RM_COURSE_CTL_TH) | Threshold to update course control in manual position mode | rad |
|
||||
| <a id="RO_YAW_RATE_LIM"></a>[RO_YAW_RATE_LIM](../advanced_config/parameter_reference.md#RO_YAW_RATE_LIM) | Maximum allowed yaw rate for the rover | deg/s |
|
||||
| <a id="RO_YAW_RATE_P"></a>[RO_YAW_RATE_P](../advanced_config/parameter_reference.md#RO_YAW_RATE_P) | Proportional gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_RATE_I"></a>[RO_YAW_RATE_I](../advanced_config/parameter_reference.md#RO_YAW_RATE_I) | Integral gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_P"></a>[RO_YAW_P](../advanced_config/parameter_reference.md#RO_YAW_P) | Proportional gain for yaw controller | - |
|
||||
| <a id="RO_SPEED_LIM"></a>[RO_SPEED_LIM](../advanced_config/parameter_reference.md#RO_SPEED_LIM) | Maximum allowed speed for the rover (and default mission speed). | m/s |
|
||||
| <a id="RO_MAX_THR_SPEED"></a>[RO_MAX_THR_SPEED](../advanced_config/parameter_reference.md#RO_MAX_THR_SPEED) | Speed the rover drives at maximum throttle | m/s |
|
||||
| <a id="RO_SPEED_P"></a>[RO_SPEED_P](../advanced_config/parameter_reference.md#RO_SPEED_P) | Proportional gain for speed controller | - |
|
||||
| <a id="RO_SPEED_I"></a>[RO_SPEED_I](../advanced_config/parameter_reference.md#RO_SPEED_I) | Integral gain for speed controller | - |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter for pure pursuit | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="RO_ACCEL_LIM"></a>[RO_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_ACCEL_LIM) | (Optional) Maximum allowed acceleration | m/s^2 |
|
||||
| <a id="RO_DECEL_LIM"></a>[RO_DECEL_LIM](../advanced_config/parameter_reference.md#RO_DECEL_LIM) | (Optional) Maximum allowed deceleration | m/s^2 |
|
||||
| <a id="RO_JERK_LIM"></a>[RO_JERK_LIM](../advanced_config/parameter_reference.md#RO_JERK_LIM) | (Optional) Maximum allowed jerk | $m/s^3$ |
|
||||
| <a id="RO_YAW_ACCEL_LIM"></a>[RO_YAW_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_ACCEL_LIM) | (Optional) Maximum allowed yaw acceleration | m/s^2 |
|
||||
| <a id="RO_YAW_DECEL_LIM"></a>[RO_YAW_DECEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_DECEL_LIM) | (Optional) Maximum allowed yaw deceleration | m/s^2 |
|
||||
|
||||
## Дивіться також
|
||||
|
||||
- [Drive Modes (Mecanum Rover)](../flight_modes_rover/mecanum.md).
|
||||
@@ -1,161 +0,0 @@
|
||||
# Drive Modes (Ackermann Rover)
|
||||
|
||||
Flight modes (or more accurately "Drive modes" for ground vehicles) provide autopilot support to make it easier to manually drive the vehicle or to execute autonomous missions.
|
||||
|
||||
This section outlines all supported drive modes for [Ackermann rovers](../frames_rover/ackermann.md).
|
||||
|
||||
For information on mapping RC control switches to specific modes see: [Basic Configuration > Flight Modes](../config/flight_mode.md).
|
||||
|
||||
:::warning
|
||||
Selecting any other mode than those listed below will either stop the rover or can lead to undefined behaviour.
|
||||
:::
|
||||
|
||||
## Manual Modes
|
||||
|
||||
Manual modes require stick inputs from the user to drive the vehicle.
|
||||
|
||||
|
||||
|
||||
The sticks provide the same "high level" control effects over direction and rate of movement in all manual modes:
|
||||
|
||||
- `Left stick up/down`: Drive the rover forwards/backwards (controlling speed)
|
||||
- `Right stick left/right`: Make a left/right turn (controlling steering angle ([Manual mode](#manual-mode)) or yaw rate ([Acro](#acro-mode) and [Position](#position-mode))).
|
||||
|
||||
The manual modes provide progressively increasing levels of autopilot support for maintaining a course, speed, and rate of turn, compensating for external factors such as slopes or uneven terrain.
|
||||
|
||||
| Режим | Функції |
|
||||
| -------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | No autopilot support. User is responsible for keeping the rover on the desired course and maintaining speed and rate of turn. |
|
||||
| [Acro](#acro-mode) | + Maintains the yaw rate (This makes it feel more like driving a car than manual mode). <br>+ Allows maximum yaw rate to be limited (Protects against roll over). |
|
||||
| [Position](#position-mode) | + Maintains the course (Best mode for driving a straight line).<br>+ Maintains speed against disturbances, e.g. when driving up a hill.<br>+ Allows maximum speed to be limited. |
|
||||
|
||||
:::details
|
||||
Overview mode mapping to control effect
|
||||
|
||||
| Режим | Forward/backwards speed | Steering angle/yaw rate | Required measurements |
|
||||
| -------------------------- | ---------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | Directly map stick input to motor command. | Directly map stick input to steering angle. | None. |
|
||||
| [Acro](#acro-mode) | Directly map stick input to motor command. | Stick input creates a yaw rate setpoint for the control system to regulate. | yaw rate. |
|
||||
| [Position](#position-mode) | Stick input creates a speed setpoint for the control system to regulate. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will keep the rover driving in a straight line. | yaw rate, yaw, speed and global position (GPS). |
|
||||
|
||||
:::
|
||||
|
||||
### Ручний режим
|
||||
|
||||
In this mode the stick inputs are directly mapped to motor commands.
|
||||
The rover does not attempt to maintain a specific orientation or compensate for external factors like slopes or uneven terrain!
|
||||
The user is responsible for making the necessary adjustments to the stick inputs to keep the rover on the desired course.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Move the steering angle to the left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Manual mode](../config_rover/ackermann.md#manual-mode).
|
||||
|
||||
### Acro Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate measurement.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint (but does not stabilize heading or regulate speed).
|
||||
|
||||
Yaw rate can be directly mapped to a steering input based on the forward speed of the rover:
|
||||
|
||||
<!-- prettier-ignore -->
|
||||
|
||||
$$\delta = \arctan(\frac{w_b \cdot \dot{\psi}}{v})$$
|
||||
|
||||
with
|
||||
|
||||
- $w_b:$ Wheel base,
|
||||
- $\delta:$ Steering angle,
|
||||
- $\dot{\psi}:$ Yaw rate
|
||||
- $v:$ Forward speed.
|
||||
|
||||
For driving this means that the same right hand stick input will cause a different steering angle based on how fast you are driving.
|
||||
By limiting the maximum yaw rate, we can restrict the steering angle based on the speed, which can prevent the rover from rolling over.
|
||||
This mode will feel more like "driving a car" than [Manual mode](#manual-mode).
|
||||
|
||||
:::info
|
||||
The yaw rate is only close loop controlled when driving forwards.
|
||||
When driving backwards the yaw rate setpoint is directly mapped to a steering angle using the equation above.
|
||||
This is due to the fact that rear wheel steering (driving a car with front-wheel steering backwards) is non-minimum-phase w.r.t to the yaw rate which leads to instabilities when doing closed loop control.
|
||||
:::
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will attempt to maintain a zero yaw rate (minimal disturbance rejection) |
|
||||
|
||||
For the configuration/tuning of this mode see [Acro mode](../config_rover/ackermann.md#acro-mode).
|
||||
|
||||
### Stabilized Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate and yaw estimate.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint and will maintain its heading if this setpoint is zero (but does not regulate speed).
|
||||
Compared to [Acro mode](#acro-mode), this mode is much better at driving in a straight line as it can more effectively reject disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the current yaw. |
|
||||
|
||||
For the configuration/tuning of this mode see [Stabilized mode](../config_rover/ackermann.md#stabilized-mode).
|
||||
|
||||
### Position Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate, yaw, speed and global position estimate.
|
||||
:::
|
||||
|
||||
This is the manual mode with the most autopilot support.
|
||||
The vehicle regulates its yaw rate and speed to a setpoint.
|
||||
If the yaw rate setpoint is zero, the controller will remember the GPS coordinates and yaw (heading) of the vehicle and use those to construct a line that the rover will then follow (course control).
|
||||
This offers the highest amount of disturbance rejection, which leads to the best straight line driving behavior.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| Left stick up/down | Stick position sets a forward/back speed setpoint. The vehicle attempts to maintain this speed on slopes etc. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the course of the rover. |
|
||||
|
||||
For the configuration/tuning of this mode see [Position mode](../config_rover/ackermann.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
In auto modes the autopilot takes over control of the vehicle to run missions, return to launch, or perform other autonomous navigation tasks.
|
||||
For the tuning process see the configuration for [Auto modes](../config_rover/ackermann.md#auto-modes).
|
||||
|
||||
### Mission Mode
|
||||
|
||||
_Mission mode_ is an automatic mode that causes the vehicle to execute a predefined autonomous [mission plan](../flying/missions.md) that has been uploaded to the flight controller.
|
||||
The mission is typically created and uploaded with a Ground Control Station (GCS) application, such as [QGroundControl](https://docs.qgroundcontrol.com/master/en/).
|
||||
|
||||
#### Mission commands
|
||||
|
||||
The following commands can be used in missions at time of writing (PX4 v1.16):
|
||||
|
||||
| QGC mission item | Команда | Опис |
|
||||
| ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------- |
|
||||
| Mission start | [MAV_CMD_MISSION_START](MAV_CMD_MISSION_START) | Starts the mission. |
|
||||
| Waypoint | [MAV_CMD_NAV_WAYPOINT](MAV_CMD_NAV_WAYPOINT) | Navigate to waypoint. |
|
||||
| Return to launch | [MAV\_CMD\_NAV\_RETURN\_TO\_LAUNCH][MAV_CMD_NAV_RETURN_TO_LAUNCH] | Return to the launch location. |
|
||||
| Change speed | [MAV\_CMD\_DO\_CHANGE\_SPEED][MAV_CMD_DO_CHANGE_SPEED] | Change the speed setpoint |
|
||||
| Set launch location | [MAV_CMD_DO_SET_HOME](MAV_CMD_DO_SET_HOME) | Changes launch location to specified coordinates. |
|
||||
| Jump to item (all) | [MAV\_CMD\_DO\_JUMP][MAV_CMD_DO_JUMP] (and other jump commands) | Jump to specified mission item. |
|
||||
|
||||
[MAV_CMD_MISSION_START]: https://mavlink.io/en/messages/common.html#MAV_CMD_MISSION_START
|
||||
[MAV_CMD_NAV_WAYPOINT]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_WAYPOINT
|
||||
[MAV_CMD_NAV_RETURN_TO_LAUNCH]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_RETURN_TO_LAUNCH
|
||||
[MAV_CMD_DO_CHANGE_SPEED]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_CHANGE_SPEED
|
||||
[MAV_CMD_DO_SET_HOME]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_SET_HOME
|
||||
[MAV_CMD_DO_JUMP]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_JUMP
|
||||
|
||||
### Return Mode
|
||||
|
||||
This mode uses the [pure pursuit guidance logic](../config_rover/ackermann.md#pure-pursuit-guidance-logic) with the launch position as goal.
|
||||
Return mode can be activated through the respective [mission command](#mission-commands) or through the ground station UI.
|
||||
@@ -1,143 +0,0 @@
|
||||
# Drive Modes (Differential Rover)
|
||||
|
||||
Flight modes (or more accurately "Drive modes" for ground vehicles) provide autopilot support to make it easier to manually drive the vehicle or to execute autonomous missions.
|
||||
|
||||
This section outlines all supported drive modes for differential rovers.
|
||||
|
||||
For information on mapping RC control switches to specific modes see: [Basic Configuration > Flight Modes](../config/flight_mode.md).
|
||||
|
||||
:::warning
|
||||
Selecting any other mode than those listed below will either stop the rover or can lead to undefined behaviour.
|
||||
:::
|
||||
|
||||
## Manual Modes
|
||||
|
||||
Manual modes require stick inputs from the user to drive the vehicle.
|
||||
|
||||
|
||||
|
||||
The sticks provide the same "high level" control effects over direction and rate of movement in all manual modes:
|
||||
|
||||
- `Left stick up/down`: Drive the rover forwards/backwards (controlling speed)
|
||||
- `Right stick left/right`: Rotate the rover to the left/right (controlling yaw rate).
|
||||
|
||||
The manual modes provide progressively increasing levels of autopilot support for maintaining a course, speed, and rate of turn, compensating for external factors such as slopes or uneven terrain.
|
||||
|
||||
| Режим | Функції |
|
||||
| ------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | No autopilot support. User is responsible for keeping the rover on the desired course and maintaining speed and rate of turn. |
|
||||
| [Acro](#acro-mode) | + Maintains the yaw rate (This makes it slightly better at holding a straight line in uneven terrain). <br>+ Allows maximum yaw rate to be limited. |
|
||||
| [Stabilized](#stabilized-mode) | + Maintans the yaw (This makes it significantly better at holding a straight line). |
|
||||
| [Position](#position-mode) | + Maintains the course (Best mode for driving a straight line).<br>+ Maintains speed against disturbances, e.g. when driving up a hill.<br>+ Allows maximum speed to be limited. |
|
||||
|
||||
:::details
|
||||
Overview mode mapping to control effect
|
||||
|
||||
| Режим | Forwards/backwards speed | Швидкість крену | Required measurements |
|
||||
| ------------------------------ | ---------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | Directly map stick input to motor commands. | Directly map stick input to motor commands. | None. |
|
||||
| [Acro](#acro-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. | Yaw rate. |
|
||||
| [Stabilized](#stabilized-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will maintain the current yaw (heading) of the rover. | Yaw rate and yaw. |
|
||||
| [Position](#position-mode) | Stick input creates a speed setpoint for the control system to regulate. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will keep the rover driving in a straight line. | Yaw rate, yaw, speed and global position (GPS). |
|
||||
|
||||
:::
|
||||
|
||||
### Ручний режим
|
||||
|
||||
In this mode the stick inputs are directly mapped to motor commands. The rover does not attempt to maintain a specific orientation or compensate for external factors like slopes or uneven terrain!
|
||||
The user is responsible for making the necessary adjustments to the stick inputs to keep the rover on the desired course.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | --------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Yaw the rover to the left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Manual mode](../config_rover/differential.md#manual-mode).
|
||||
|
||||
### Acro Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate measurement.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint (but does not stabilize heading or regulate speed).
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will attempt to maintain a zero yaw rate (minimal disturbance rejection) |
|
||||
|
||||
For the configuration/tuning of this mode see [Acro mode](../config_rover/differential.md#acro-mode).
|
||||
|
||||
### Stabilized Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate and yaw estimate.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint and will maintain its heading if this setpoint is zero (but does not regulate speed).
|
||||
Compared to [Acro mode](#acro-mode), this mode is much better at driving in a straight line as it can more effectively reject disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the current yaw. |
|
||||
|
||||
For the configuration/tuning of this mode see [Stabilized mode](../config_rover/differential.md#stabilized-mode).
|
||||
|
||||
### Position Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate, yaw, speed and global position estimate.
|
||||
:::
|
||||
|
||||
This is the manual mode with the most autopilot support.
|
||||
The vehicle regulates its yaw rate and speed to a setpoint.
|
||||
If the yaw rate setpoint is zero, the controller will remember the GNSS coordinates and yaw (heading) of the vehicle and use those to construct a line that the rover will then follow (course control).
|
||||
This offers the highest amount of disturbance rejection, which leads to the best straight line driving behavior.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| Left stick up/down | Create a speed setpoint for the control system to regulate. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the course of the rover. |
|
||||
|
||||
For the configuration/tuning of this mode see [Position mode](../config_rover/differential.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
In auto modes the autopilot takes over control of the vehicle to run missions, return to launch, or perform other autonomous navigation tasks.
|
||||
For the configuration/tuning of these modes see [Auto Modes](../config_rover/differential.md#auto-modes).
|
||||
|
||||
### Mission Mode
|
||||
|
||||
_Mission mode_ is an automatic mode in which the vehicle executes a predefined autonomous [mission plan](../flying/missions.md) that has been uploaded to the flight controller.
|
||||
The mission is typically created and uploaded with a Ground Control Station (GCS) application, such as [QGroundControl](https://docs.qgroundcontrol.com/master/en/).
|
||||
|
||||
#### Mission commands
|
||||
|
||||
The following commands can be used in missions at time of writing (PX4 v1.16):
|
||||
|
||||
| QGC mission item | Команда | Опис |
|
||||
| ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------ |
|
||||
| Mission start | [MAV_CMD_MISSION_START](MAV_CMD_MISSION_START) | Starts the mission. |
|
||||
| Waypoint | [MAV_CMD_NAV_WAYPOINT](MAV_CMD_NAV_WAYPOINT) | Navigate to waypoint. |
|
||||
| Return to launch | [MAV\_CMD\_NAV\_RETURN\_TO\_LAUNCH][MAV_CMD_NAV_RETURN_TO_LAUNCH] | Return to the launch location. |
|
||||
| Delay until | [MAV_CMD_NAV_DELAY](MAV_CMD_NAV_DELAY) | The rover will stop for a specified amount of time. |
|
||||
| Change speed | [MAV\_CMD\_DO\_CHANGE\_SPEED][MAV_CMD_DO_CHANGE_SPEED] | Change the speed setpoint |
|
||||
| Set launch location | [MAV_CMD_DO_SET_HOME](MAV_CMD_DO_SET_HOME) | Changes launch location to specified coordinates. |
|
||||
| Jump to item (all) | [MAV\_CMD\_DO\_JUMP][MAV_CMD_DO_JUMP] (and other jump commands) | Jump to specified mission item. |
|
||||
| Loiter (all) | [MAV\_CMD\_NAV\_LOITER\_TIME][MAV_CMD_NAV_LOITER_TIME] (and other loiter commands) | Stop the rover for given time. Other commands stop indefinitely. |
|
||||
|
||||
[MAV_CMD_MISSION_START]: https://mavlink.io/en/messages/common.html#MAV_CMD_MISSION_START
|
||||
[MAV_CMD_NAV_WAYPOINT]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_WAYPOINT
|
||||
[MAV_CMD_NAV_RETURN_TO_LAUNCH]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_RETURN_TO_LAUNCH
|
||||
[MAV_CMD_NAV_DELAY]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_DELAY
|
||||
[MAV_CMD_DO_CHANGE_SPEED]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_CHANGE_SPEED
|
||||
[MAV_CMD_DO_SET_HOME]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_SET_HOME
|
||||
[MAV_CMD_NAV_LOITER_TIME]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_LOITER_TIME
|
||||
[MAV_CMD_DO_JUMP]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_JUMP
|
||||
|
||||
### Return Mode
|
||||
|
||||
This mode uses the [pure pursuit guidance logic](../config_rover/differential.md#pure-pursuit-guidance-logic) with the launch position as goal.
|
||||
Return mode can be activated through the respective [mission command](#mission-commands) or through the ground station UI.
|
||||
@@ -1,168 +0,0 @@
|
||||
# Drive Modes (Mecanum Rover)
|
||||
|
||||
Flight modes (or more accurately "Drive modes" for ground vehicles) provide autopilot support to make it easier to manually drive the vehicle or to execute autonomous missions.
|
||||
|
||||
This section outlines all supported drive modes for mecanum rovers.
|
||||
|
||||
For information on mapping RC control switches to specific modes see: [Basic Configuration > Flight Modes](../config/flight_mode.md).
|
||||
|
||||
:::warning
|
||||
Selecting any other mode than those listed below will either stop the rover or can lead to undefined behaviour.
|
||||
:::
|
||||
|
||||
## Manual Modes
|
||||
|
||||
Manual modes require stick inputs from the user to drive the vehicle.
|
||||
|
||||
|
||||
|
||||
The sticks provide the same "high level" control effects over direction and rate of movement in all manual modes:
|
||||
|
||||
- `Left stick up/down`: Drive the rover forwards/backwards (controlling speed)
|
||||
- `Left stick left/right`: Yaw the rover to the left/right (controlling yaw rate).
|
||||
- `Right stick left/right`: Drive the rover left/right (controlling speed).
|
||||
|
||||
The manual modes provide progressively increasing levels of autopilot support for maintaining a course, speed, and rate of turn, compensating for external factors such as slopes or uneven terrain.
|
||||
|
||||
| Режим | Функції |
|
||||
| ------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| [Manual](#manual-mode) | No autopilot support. User is responsible for keeping the rover on the desired course and maintaining speed and rate of turn. |
|
||||
| [Acro](#acro-mode) | + Maintains yaw rate (This makes it slightly better at holding a straight line in uneven terrain). <br>+ Allows maximum yaw rate to be limited. |
|
||||
| [Stabilized](#stabilized-mode) | + Maintains yaw (This makes it significantly better at holding a straight line) . |
|
||||
| [Position](#position-mode) | + Best mode for holding a straight line.<br>+ Maintains speed against disturbances, e.g. when driving up a hill<br>+ Allows maximum speed to be limited. |
|
||||
|
||||
:::details
|
||||
Overview mode mapping to control effect
|
||||
|
||||
| Режим | Longitudinal/Lateral speed | Швидкість крену | Required measurements |
|
||||
| ------------------------------ | ------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | Directly map stick input to motor commands. | Directly map stick input to motor commands. | None. |
|
||||
| [Acro](#acro-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. | Yaw rate. |
|
||||
| [Stabilized](#stabilized-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will maintain the current yaw (heading) of the rover. | Yaw rate and yaw. |
|
||||
| [Position](#position-mode) | Stick input creates a velocity setpoint for the control system to regulate. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will keep the rover driving in a straight line. | Yaw rate, yaw, velocity and global position (GPS). |
|
||||
|
||||
:::
|
||||
|
||||
### Ручний режим
|
||||
|
||||
In this mode the stick inputs are directly mapped to motor commands.
|
||||
The rover does not attempt to maintain a specific orientation or compensate for external factors like slopes or uneven terrain!
|
||||
The user is responsible for making the necessary adjustments to the stick inputs to keep the rover on the desired course.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | --------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Left stick left/right | Yaw the rover to the left/right. |
|
||||
| Right stick left/right | Drive the rover left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Manual mode](../config_rover/mecanum.md#manual-mode).
|
||||
|
||||
### Acro Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate measurement.
|
||||
:::
|
||||
|
||||
The vehicle regulates its yaw rate (Left stick left/right) to a setpoint, and a maximum yaw rate can also be specified.
|
||||
Heading and speed are not controlled.
|
||||
|
||||
Compared to [Manual mode](#manual-mode) this introduces the following new features:
|
||||
|
||||
- The yaw rate control ensures that the rover turns at the requested rate even on different surfaces and due to other external forces (such as wind).
|
||||
- Slightly better at driving in a straight line because if the input is zero PX4 will attempt to maintain a zero yaw rate.
|
||||
This is resistant to minor disturbances.
|
||||
- Upper limit for the yaw rate can be used to tune how aggressive the rover turns.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Left stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will attempt to maintain a zero yaw rate (minimal disturbance rejection) |
|
||||
| Right stick left/right | Drive the rover left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Acro mode](../config_rover/mecanum.md#acro-mode).
|
||||
|
||||
### Stabilized Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate and yaw estimate.
|
||||
:::
|
||||
|
||||
The vehicle regulates its yaw rate to a setpoint, and a maximum yaw rate can also be specified.
|
||||
The vehicle regulates its yaw to a setpoint when the yaw rate setpoint is zero, maintaining the heading.
|
||||
Speed is not controlled.
|
||||
|
||||
Compared to [Acro mode](#acro-mode), this mode is much better at driving in a straight line as it can more effectively reject disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Left stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the current yaw. |
|
||||
| Right stick left/right | Drive the rover left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Stabilized mode](../config_rover/mecanum.md#stabilized-mode).
|
||||
|
||||
### Position Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate, yaw, speed and global position estimate.
|
||||
:::
|
||||
|
||||
This is the mode with the most autopilot support.
|
||||
|
||||
The vehicle regulates its yaw rate to a setpoint, and a maximum yaw rate can also be specified.
|
||||
The path is maintained when the yaw rate setpoint is zero using global position (the controller constructs a line in the direction of the velocity input (forward + lateral speed) that the rover will then follow by tracking the global position).
|
||||
Speed is regulated to a setpoint, and a maximum value can be set.
|
||||
|
||||
Compared to [Stabilized Mode](#stabilized-mode) this introduces the following features:
|
||||
|
||||
- Upper limit for the speed (see [Position Mode](../config_rover/mecanum.md#position-mode)) to tune how fast the rover is allowed to drive.
|
||||
- The speed control ensures that the rover drives the requested speed even under disturbances (i.e. driving up a hill, against wind, with a heavier payload etc.).
|
||||
- The course control leads to the best straight line driving behaviour, as the vehicle will follow the intended path of the vehicle and return to it if forced off-track
|
||||
This is much better than stabilized mode, which can be forced off the intended track by disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| Left stick up/down | Create a forward speed setpoint for the control system to regulate. |
|
||||
| Left stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the course of the rover. |
|
||||
| Right stick left/right | Create a lateral speed setpoint for the control system to regulate. |
|
||||
|
||||
For the configuration/tuning of this mode see [Position mode](../config_rover/mecanum.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
In auto modes the autopilot takes over control of the vehicle to run missions, return to launch, or perform other autonomous navigation tasks.
|
||||
For the configuration/tuning of these modes see [Auto Modes](../config_rover/mecanum.md#auto-modes).
|
||||
|
||||
### Mission Mode
|
||||
|
||||
_Mission mode_ is an automatic mode in which the vehicle executes a predefined autonomous [mission plan](../flying/missions.md) that has been uploaded to the flight controller.
|
||||
The mission is typically created and uploaded with a Ground Control Station (GCS) application, such as [QGroundControl](https://docs.qgroundcontrol.com/master/en/).
|
||||
|
||||
#### Mission commands
|
||||
|
||||
The following commands can be used in missions at time of writing (PX4 v1.16):
|
||||
|
||||
| QGC mission item | Команда | Опис |
|
||||
| ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------ |
|
||||
| Mission start | [MAV_CMD_MISSION_START](MAV_CMD_MISSION_START) | Starts the mission. |
|
||||
| Waypoint | [MAV_CMD_NAV_WAYPOINT](MAV_CMD_NAV_WAYPOINT) | Navigate to waypoint. |
|
||||
| Return to launch | [MAV\_CMD\_NAV\_RETURN\_TO\_LAUNCH][MAV_CMD_NAV_RETURN_TO_LAUNCH] | Return to the launch location. |
|
||||
| Delay until | [MAV_CMD_NAV_DELAY](MAV_CMD_NAV_DELAY) | The rover will stop for a specified amount of time. |
|
||||
| Change speed | [MAV\_CMD\_DO\_CHANGE\_SPEED][MAV_CMD_DO_CHANGE_SPEED] | Change the speed setpoint |
|
||||
| Set launch location | [MAV_CMD_DO_SET_HOME](MAV_CMD_DO_SET_HOME) | Changes launch location to specified coordinates. |
|
||||
| Jump to item (all) | [MAV\_CMD\_DO\_JUMP][MAV_CMD_DO_JUMP] (and other jump commands) | Jump to specified mission item. |
|
||||
| Loiter (all) | [MAV\_CMD\_NAV\_LOITER\_TIME][MAV_CMD_NAV_LOITER_TIME] (and other loiter commands) | Stop the rover for given time. Other commands stop indefinitely. |
|
||||
|
||||
[MAV_CMD_MISSION_START]: https://mavlink.io/en/messages/common.html#MAV_CMD_MISSION_START
|
||||
[MAV_CMD_NAV_WAYPOINT]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_WAYPOINT
|
||||
[MAV_CMD_NAV_RETURN_TO_LAUNCH]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_RETURN_TO_LAUNCH
|
||||
[MAV_CMD_NAV_DELAY]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_DELAY
|
||||
[MAV_CMD_DO_CHANGE_SPEED]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_CHANGE_SPEED
|
||||
[MAV_CMD_DO_SET_HOME]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_SET_HOME
|
||||
[MAV_CMD_NAV_LOITER_TIME]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_LOITER_TIME
|
||||
[MAV_CMD_DO_JUMP]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_JUMP
|
||||
|
||||
### Return Mode
|
||||
|
||||
This mode uses the [pure pursuit guidance logic](../config_rover/mecanum.md#pure-pursuit-guidance-logic) with the launch position as goal.
|
||||
Return mode can be activated through the respective [mission command](#mission-commands) or through the ground station UI.
|
||||
@@ -1,14 +0,0 @@
|
||||
# Ackermann Rovers
|
||||
|
||||
<Badge type="tip" text="PX4 v1.16" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
An _Ackermann rover_ controls its direction by pointing the front wheels in the direction of travel — the [Ackermann steering geometry](https://en.wikipedia.org/wiki/Ackermann_steering_geometry) compensates for the fact that wheels on the inside and outside of the turn move at different rates.
|
||||
This kind of steering is used on most commercial vehicles, including cars, trucks etc.
|
||||
|
||||
:::info
|
||||
PX4 does not require that the vehicle uses the Ackermann geometry and will work with any front-steering rover.
|
||||
:::
|
||||
|
||||
|
||||
|
||||
See [Configuration/Tuning](../config_rover/ackermann.md) to set up your rover and [Drive Modes](../flight_modes_rover/ackermann.md) for the supported flight (aka drive) modes.
|
||||
@@ -1,86 +0,0 @@
|
||||
# Aion Robotics R1 UGV
|
||||
|
||||
<Badge type="tip" text="PX4 v1.15" />
|
||||
|
||||
The [Aion R1](https://www.aionrobotics.com/) vehicle was chosen to test and improve the differential drive support for PX4, and to improve driver support for Roboclaw Motor Controllers, such as the [RoboClaw 2x15A](https://www.basicmicro.com/RoboClaw-2x15A-Motor-Controller_p_10.html).
|
||||
|
||||
Документація та інформація про драйвери тут також повинна полегшити роботу з контролерами Roboclaw на інших транспортних засобах, а також з транспортними засобами, такими як [Aion R6](https://www.aionrobotics.com/r6).
|
||||
|
||||
На даний момент PX4 підтримує режим MANUAL для цієї настройки.
|
||||
|
||||
|
||||
|
||||
## Список деталей
|
||||
|
||||
- [Aion R1 (Припинено)](https://www.aionrobotics.com/)
|
||||
- [Документація](https://github-docs.readthedocs.io/en/latest/r1-ugv.html)
|
||||
- [RoboClaw 2x15A](https://www.basicmicro.com/RoboClaw-2x15A-Motor-Controller_p_10.html)
|
||||
- [Характеристики R1 Roboclaw](https://resources.basicmicro.com/aion-robotics-r1-autonomous-robot/)
|
||||
- [Auterion Skynode](../companion_computer/auterion_skynode.md)
|
||||
|
||||
## Збірка
|
||||
|
||||
Збірка складається з рами, виготовленої за допомогою 3D-друку, на яку були закріплені всі частини автопілота.
|
||||
Для цієї збірки це включає [Auterion Skynode](../companion_computer/auterion_skynode.md), підключений до плати адаптера Pixhawk, яка взаємодіє з контролерами руху RoboClaw через послідовний порт.
|
||||
|
||||
|
||||
|
||||
:::info
|
||||
Якщо використовуєте стандартний Pixhawk, ви можете підключити RoboClaw до автопілота без плати адаптера.
|
||||
:::
|
||||
|
||||
RoboClaw повинен бути підключений до відповідного послідовного (UART) порту на контролері польоту, такого як `GPS2` або `TELEM1`.
|
||||
Інші з'єднання RoboClaw детально описані в розділі [Посібник користувача RoboClaw](https://downloads.basicmicro.com/docs/roboclaw_user_manual.pdf) "Проводка пакетної послідовної передачі даних" та показані нижче (ця настройка була перевірена на сумісність).
|
||||
|
||||
|
||||
|
||||
## Конфігурація PX4
|
||||
|
||||
### Конфігурація Rover
|
||||
|
||||
Використовуйте _QGroundControl_ для налаштування рухомого об'єкту:
|
||||
|
||||
1. У розділі [Основні налаштування](../config/index.md) виберіть вкладку [Каркас](../config/airframe.md).
|
||||
2. Оберіть **Aion Robotics R1 UGV** у категорії **Rover**.
|
||||
|
||||
|
||||
|
||||
### Конфігурація RoboClaw
|
||||
|
||||
Спочатку налаштуйте послідовне з'єднання:
|
||||
|
||||
1. Перейдіть до розділу [Параметри](../advanced_config/parameters.md) в QGroundControl.
|
||||
|
||||
- Встановіть параметр [RBCLW_SER_CFG](../advanced_config/parameter_reference.md#RBCLW_SER_CFG) на послідовний порт, до якого підключений RoboClaw (наприклад, `GPS2`).
|
||||
- [RBCLW_COUNTS_REV](../advanced_config/parameter_reference.md#RBCLW_COUNTS_REV) визначає кількість лічильників енкодера, необхідних для одного оберту колеса.
|
||||
Це значення повинно бути залишено на `1200` для протестованого `Контролера руху RoboClaw 2x15A`.
|
||||
Відрегулюйте значення на основі вашого конкретного енкодера та налаштувань колеса.
|
||||
- Контролери моторів RoboClaw повинні мати унікальну адресу на шині.
|
||||
Стандартна адреса - 128, і вам не потрібно її змінювати (якщо ви це робите, оновіть параметр PX4 [RBCLW_ADDRESS](../advanced_config/parameter_reference.md#RBCLW_ADDRESS) відповідно).
|
||||
|
||||
:::info
|
||||
PX4 не підтримує кілька контролерів моторів RoboClaw у тому ж транспортному засобі — кожен контролер повинен мати унікальну адресу на шині, і є лише один параметр для встановлення адреси в PX4 (`RBCLW_ADDRESS`).
|
||||
|
||||
:::
|
||||
|
||||
Потім налаштуйте конфігурацію приводу:
|
||||
|
||||
1. Перейдіть до [Конфігурації та тестування приводів](../config/actuators.md) в QGroundControl.
|
||||
2. Виберіть драйвер RoboClaw зі списку _Виводів приводів_.
|
||||
|
||||
Для призначень каналу, роззброю, мінімальних та максимальних значень, будь ласка, звертайтеся до зображення нижче.
|
||||
|
||||
|
||||
|
||||
Для систем з більш ніж двома двигунами можливо призначити одну й ту ж функцію кільком двигунам.
|
||||
Причина нестандартних значень можна знайти в [Користувацькому посібнику RoboClaw](https://downloads.basicmicro.com/docs/roboclaw_user_manual.pdf) під `Командами сумісності` для `Пакетної послідовної передачі даних`:
|
||||
|
||||
```plain
|
||||
Приводити двигун вперед. Діапазон дійсних даних - від 0 до 127. Значення 127 = повна швидкість вперед, 64 =
|
||||
приблизно напівшвидкість вперед і 0 = повна зупинка.
|
||||
```
|
||||
|
||||
## Дивись також
|
||||
|
||||
- [roboclaw](../modules/modules_driver.md#roboclaw) driver
|
||||
- [Посібник користувача Roboclaw](https://downloads.basicmicro.com/docs/roboclaw_user_manual.pdf)
|
||||
@@ -1,11 +0,0 @@
|
||||
# Differential Rovers
|
||||
|
||||
<Badge type="tip" text="PX4 v1.16" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
A differential rover's motion is controlled using a differential drive mechanism, where the left and right wheel speeds are adjusted independently to achieve the desired forward speed and yaw rate.
|
||||
Forward motion is achieved by driving both wheels at the same speed in the same direction.
|
||||
Rotation is achieved by driving the wheels at different speeds in opposite directions, allowing the rover to turn on the spot.
|
||||
|
||||
|
||||
|
||||
See [Configuration/Tuning](../config_rover/differential.md) to set up your rover and [Drive Modes](../flight_modes_rover/differential.md) for the supported flight (aka drive) modes.
|
||||
@@ -1,10 +0,0 @@
|
||||
# Mecanum Rovers
|
||||
|
||||
<Badge type="tip" text="PX4 v1.16" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
A Mecanum rover is a type of mobile robot that uses Mecanum wheels to achieve omnidirectional movement. These wheels are unique because they have rollers mounted at a 45-degree angle around their circumference, allowing the rover to move not only forward and backward but also side-to-side and diagonally without needing to rotate first.
|
||||
Each wheel is driven by its own motor, and by controlling the speed and direction of each motor, the rover can move in any direction or spin in place.
|
||||
|
||||
|
||||
|
||||
See [Configuration/Tuning](../config_rover/mecanum.md) to set up your rover and [Drive Modes](../flight_modes_rover/mecanum.md) for the supported flight (aka drive) modes.
|
||||
@@ -1,15 +0,0 @@
|
||||
# Buffer128 (повідомлення UORB)
|
||||
|
||||
[вихідний файл](https://github.com/PX4/PX4-Autopilot/blob/main/msg/Buffer128.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 len # length of data
|
||||
uint32 MAX_BUFLEN = 128
|
||||
|
||||
uint8[128] data # data
|
||||
|
||||
# TOPICS voxl2_io_data
|
||||
|
||||
```
|
||||
@@ -1,15 +0,0 @@
|
||||
# CollisionReport (повідомлення UORB)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/CollisionReport.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
uint8 src
|
||||
uint32 id
|
||||
uint8 action
|
||||
uint8 threat_level
|
||||
float32 time_to_minimum_delta
|
||||
float32 altitude_minimum_delta
|
||||
float32 horizontal_minimum_delta
|
||||
|
||||
```
|
||||
@@ -1,15 +0,0 @@
|
||||
# DifferentialDriveSetpoint (повідомлення UORB)
|
||||
|
||||
[вихідний файл](https://github.com/PX4/PX4-Autopilot/blob/main/msg/DifferentialDriveSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 speed # [m/s] collective roll-off speed in body x-axis
|
||||
bool closed_loop_speed_control # true if speed is controlled using estimator feedback, false if direct feed-forward
|
||||
float32 yaw_rate # [rad/s] yaw rate
|
||||
bool closed_loop_yaw_rate_control # true if yaw rate is controlled using gyroscope feedback, false if direct feed-forward
|
||||
|
||||
# TOPICS differential_drive_setpoint differential_drive_control_output
|
||||
|
||||
```
|
||||
@@ -1,24 +0,0 @@
|
||||
# NpfgStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/NpfgStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 wind_est_valid # (boolean) true = wind estimate is valid and/or being used by controller (also indicates if wind est usage is disabled despite being valid)
|
||||
float32 lat_accel # resultant lateral acceleration reference [m/s^2]
|
||||
float32 lat_accel_ff # lateral acceleration demand only for maintaining curvature [m/s^2]
|
||||
float32 bearing_feas # bearing feasibility [0,1]
|
||||
float32 bearing_feas_on_track # on-track bearing feasibility [0,1]
|
||||
float32 signed_track_error # signed track error [m]
|
||||
float32 track_error_bound # track error bound [m]
|
||||
float32 airspeed_ref # (true) airspeed reference [m/s]
|
||||
float32 bearing # bearing angle [rad]
|
||||
float32 heading_ref # heading angle reference [rad]
|
||||
float32 min_ground_speed_ref # minimum forward ground speed reference [m/s]
|
||||
float32 adapted_period # adapted period (if auto-tuning enabled) [s]
|
||||
float32 p_gain # controller proportional gain [rad/s]
|
||||
float32 time_const # controller time constant [s]
|
||||
float32 can_run_factor # estimate of certainty of the correct functionality of the npfg roll setpoint in [0, 1]
|
||||
|
||||
```
|
||||
@@ -1,13 +0,0 @@
|
||||
# RoverAckermannGuidanceStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverAckermannGuidanceStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 lookahead_distance # [m] Lookahead distance of pure the pursuit controller
|
||||
float32 heading_error # [deg] Heading error of the pure pursuit controller
|
||||
|
||||
# TOPICS rover_ackermann_guidance_status
|
||||
|
||||
```
|
||||
@@ -1,16 +0,0 @@
|
||||
# RoverAckermannSetpoint (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverAckermannSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 forward_speed_setpoint # [m/s] Desired speed in body x direction. Positiv: forwards, Negativ: backwards
|
||||
float32 forward_speed_setpoint_normalized # [-1, 1] Desired normalized speed in body x direction. Positiv: forwards, Negativ: backwards
|
||||
float32 steering_setpoint # [rad] Desired steering angle
|
||||
float32 steering_setpoint_normalized # [-1, 1] Desired normalized steering angle
|
||||
float32 lateral_acceleration_setpoint # [m/s^2] Desired acceleration in body y direction. Positiv: right, Negativ: left.
|
||||
|
||||
# TOPICS rover_ackermann_setpoint
|
||||
|
||||
```
|
||||
@@ -1,18 +0,0 @@
|
||||
# RoverAckermannStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverAckermannStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 measured_forward_speed # [m/s] Measured speed in body x direction. Forwards: positiv, Backwards: negativ
|
||||
float32 adjusted_forward_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 steering_setpoint_normalized # [-1, 1] Normalized steering setpoint
|
||||
float32 adjusted_steering_setpoint_normalized # [-1, 1] Normalized steering setpoint after applying slew rate
|
||||
float32 measured_lateral_acceleration # [m/s^2] Measured acceleration in body y direction. Positiv: right, Negativ: left.
|
||||
float32 pid_throttle_integral # Integral of the PID for the closed loop speed controller
|
||||
float32 pid_lat_accel_integral # Integral of the PID for the closed loop lateral acceleration controller
|
||||
|
||||
# TOPICS rover_ackermann_status
|
||||
|
||||
```
|
||||
@@ -1,14 +0,0 @@
|
||||
# RoverDifferentialGuidanceStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverDifferentialGuidanceStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 lookahead_distance # [m] Lookahead distance of pure the pursuit controller
|
||||
float32 heading_error_deg # [deg] Heading error of the pure pursuit controller
|
||||
uint8 state_machine # Driving state of the rover [0: SPOT_TURNING, 1: DRIVING, 2: GOAL_REACHED]
|
||||
|
||||
# TOPICS rover_differential_guidance_status
|
||||
|
||||
```
|
||||
@@ -1,16 +0,0 @@
|
||||
# RoverDifferentialSetpoint (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverDifferentialSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 forward_speed_setpoint # [m/s] Desired forward speed for the rover
|
||||
float32 forward_speed_setpoint_normalized # [-1, 1] Normalized forward speed for the rover
|
||||
float32 yaw_rate_setpoint # [rad/s] Desired yaw rate for the rover (Overriden by yaw controller if yaw_setpoint is used)
|
||||
float32 speed_diff_setpoint_normalized # [-1, 1] Normalized speed difference between the left and right wheels
|
||||
float32 yaw_setpoint # [rad] Desired yaw (heading) for the rover
|
||||
|
||||
# TOPICS rover_differential_setpoint
|
||||
|
||||
```
|
||||
@@ -1,21 +0,0 @@
|
||||
# RoverDifferentialStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverDifferentialStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 measured_forward_speed # [m/s] Measured speed in body x direction. Forwards: positiv, Backwards: negativ
|
||||
float32 adjusted_forward_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 measured_yaw # [rad] Measured yaw
|
||||
float32 adjusted_yaw_setpoint # [rad] Yaw setpoint after applying slew rate
|
||||
float32 clyaw_yaw_rate_setpoint # [rad/s] Yaw rate setpoint output by the closed loop yaw controller
|
||||
float32 measured_yaw_rate # [rad/s] Measured yaw rate
|
||||
float32 adjusted_yaw_rate_setpoint # [rad/s] Yaw rate setpoint from the closed loop yaw controller
|
||||
float32 pid_yaw_integral # Integral of the PID for the closed loop yaw controller
|
||||
float32 pid_yaw_rate_integral # Integral of the PID for the closed loop yaw rate controller
|
||||
float32 pid_throttle_integral # Integral of the PID for the closed loop speed controller
|
||||
|
||||
# TOPICS rover_differential_status
|
||||
|
||||
```
|
||||
@@ -1,14 +0,0 @@
|
||||
# RoverMecanumGuidanceStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverMecanumGuidanceStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 lookahead_distance # [m] Lookahead distance of pure the pursuit controller
|
||||
float32 heading_error # [rad] Heading error of the pure pursuit controller
|
||||
float32 desired_speed # [m/s] Desired velocity magnitude (speed)
|
||||
|
||||
# TOPICS rover_mecanum_guidance_status
|
||||
|
||||
```
|
||||
@@ -1,18 +0,0 @@
|
||||
# RoverMecanumSetpoint (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverMecanumSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 forward_speed_setpoint # [m/s] Desired forward speed
|
||||
float32 forward_speed_setpoint_normalized # [-1, 1] Desired normalized forward speed
|
||||
float32 lateral_speed_setpoint # [m/s] Desired lateral speed
|
||||
float32 lateral_speed_setpoint_normalized # [-1, 1] Desired normalized lateral speed
|
||||
float32 yaw_rate_setpoint # [rad/s] Desired yaw rate
|
||||
float32 speed_diff_setpoint_normalized # [-1, 1] Normalized speed difference between the left and right wheels
|
||||
float32 yaw_setpoint # [rad] Desired yaw (heading)
|
||||
|
||||
# TOPICS rover_mecanum_setpoint
|
||||
|
||||
```
|
||||
@@ -1,24 +0,0 @@
|
||||
# RoverMecanumStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverMecanumStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 measured_forward_speed # [m/s] Measured speed in body x direction. Positiv: forwards, Negativ: backwards
|
||||
float32 adjusted_forward_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 measured_lateral_speed # [m/s] Measured speed in body y direction. Positiv: right, Negativ: left
|
||||
float32 adjusted_lateral_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 measured_yaw_rate # [rad/s] Measured yaw rate
|
||||
float32 clyaw_yaw_rate_setpoint # [rad/s] Yaw rate setpoint output by the closed loop yaw controller
|
||||
float32 adjusted_yaw_rate_setpoint # [rad/s] Yaw rate setpoint from the closed loop yaw controller
|
||||
float32 measured_yaw # [rad] Measured yaw
|
||||
float32 adjusted_yaw_setpoint # [rad] Yaw setpoint after applying slew rate
|
||||
float32 pid_yaw_rate_integral # Integral of the PID for the closed loop yaw rate controller
|
||||
float32 pid_yaw_integral # Integral of the PID for the closed loop yaw controller
|
||||
float32 pid_forward_throttle_integral # Integral of the PID for the closed loop forward speed controller
|
||||
float32 pid_lateral_throttle_integral # Integral of the PID for the closed loop lateral speed controller
|
||||
|
||||
# TOPICS rover_mecanum_status
|
||||
|
||||
```
|
||||
@@ -1,18 +0,0 @@
|
||||
# TrjectoryBezier (UORB повідомлення)
|
||||
|
||||
Опис траекторії Безьє. Див. також Повідомлення Mavlink TRAJECTORY
|
||||
Тема trajectory_bezier описує кожну точку маршруту, визначену в vehicle_trajectory_bezier
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/TrajectoryBezier.msg)
|
||||
|
||||
```c
|
||||
# Bezier Trajectory description. See also Mavlink TRAJECTORY msg
|
||||
# The topic trajectory_bezier describe each waypoint defined in vehicle_trajectory_bezier
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32[3] position # local position x,y,z (metres)
|
||||
float32 yaw # yaw angle (rad)
|
||||
float32 delta # time it should take to get to this waypoint, if this is the final waypoint (seconds)
|
||||
|
||||
```
|
||||
@@ -1,23 +0,0 @@
|
||||
# TrajectoryWaypoint (Повідомлення UORB)
|
||||
|
||||
Опис траекторії точки маршруту. Див. також Повідомлення Mavlink TRAJECTORY
|
||||
Тема trajectory_waypoint описує кожну точку маршруту, визначену в vehicle_trajectory_waypoint
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/TrajectoryWaypoint.msg)
|
||||
|
||||
```c
|
||||
# Waypoint Trajectory description. See also Mavlink TRAJECTORY msg
|
||||
# The topic trajectory_waypoint describe each waypoint defined in vehicle_trajectory_waypoint
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32[3] position
|
||||
float32[3] velocity
|
||||
float32[3] acceleration
|
||||
float32 yaw
|
||||
float32 yaw_speed
|
||||
|
||||
bool point_valid
|
||||
uint8 type
|
||||
|
||||
```
|
||||
@@ -1,29 +0,0 @@
|
||||
# VehicleTrajectoryBezier (Повідомлення UORB)
|
||||
|
||||
Опис Vehicle Waypoints Trajectory. Дивіться також MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
Тема vehicle_trajectory_bezier використовується для надсилання плавної траєкторії польоту від
|
||||
комп'ютера-супутника/модуля уникання перешкод до контролера положення.
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/VehicleTrajectoryBezier.msg)
|
||||
|
||||
```c
|
||||
# Vehicle Waypoints Trajectory description. See also MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
# The topic vehicle_trajectory_bezier is used to send a smooth flight path from the
|
||||
# companion computer / avoidance module to the position controller.
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 POINT_0 = 0
|
||||
uint8 POINT_1 = 1
|
||||
uint8 POINT_2 = 2
|
||||
uint8 POINT_3 = 3
|
||||
uint8 POINT_4 = 4
|
||||
|
||||
uint8 NUMBER_POINTS = 5
|
||||
|
||||
TrajectoryBezier[5] control_points
|
||||
uint8 bezier_order
|
||||
|
||||
# TOPICS vehicle_trajectory_bezier
|
||||
|
||||
```
|
||||
@@ -1,32 +0,0 @@
|
||||
# VehicleTrajectoryWaypoint (повідомлення UORB)
|
||||
|
||||
Опис Vehicle Waypoints Trajectory. Дивіться також MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
Тема vehicle_trajectory_waypoint_desired використовується для надсилання користувачем бажаних точок шляху від контролера положення до комп'ютера-супутника/модуля уникання перешкод.
|
||||
Тема vehicle_trajectory_waypoint використовується для надсилання відкоригованих точок маршруту від комп'ютера-супутника/модуля уникання перешкод до контролера положення.
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/VehicleTrajectoryWaypoint.msg)
|
||||
|
||||
```c
|
||||
# Vehicle Waypoints Trajectory description. See also MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
# The topic vehicle_trajectory_waypoint_desired is used to send the user desired waypoints from the position controller to the companion computer / avoidance module.
|
||||
# The topic vehicle_trajectory_waypoint is used to send the adjusted waypoints from the companion computer / avoidance module to the position controller.
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 MAV_TRAJECTORY_REPRESENTATION_WAYPOINTS = 0
|
||||
|
||||
uint8 type # Type from MAV_TRAJECTORY_REPRESENTATION enum.
|
||||
|
||||
uint8 POINT_0 = 0
|
||||
uint8 POINT_1 = 1
|
||||
uint8 POINT_2 = 2
|
||||
uint8 POINT_3 = 3
|
||||
uint8 POINT_4 = 4
|
||||
|
||||
uint8 NUMBER_POINTS = 5
|
||||
|
||||
TrajectoryWaypoint[5] waypoints
|
||||
|
||||
# TOPICS vehicle_trajectory_waypoint vehicle_trajectory_waypoint_desired
|
||||
|
||||
```
|
||||
@@ -1,457 +0,0 @@
|
||||
# Configuration/Tuning (Ackermann Rover)
|
||||
|
||||
This topic provides a step-by-step guide for setting up your [Ackermann rover](../frames_rover/ackermann.md).
|
||||
|
||||
Successive steps enable [drive modes](../flight_modes_rover/ackermann.md) with more autopilot support and features.
|
||||
|
||||
:::warning
|
||||
Each step is dependent on the previous steps having been completed.
|
||||
Modes will only work properly if the preceding modes have been configured.
|
||||
:::
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To configure the Ackermann rover frame and outputs:
|
||||
|
||||
1. Enable Rover support by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
Note that this is a special build that contains rover-specific modules.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select the _Generic Rover Ackermann_:
|
||||
|
||||
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe is not displayed and you have checked that you are using rover firmware (not the default), you can alternatively enable this frame by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `51000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Open the [Actuators Configuration & Testing](../config/actuators.md) to map the steering and throttle functions to flight controller outputs.
|
||||
|
||||
## 手动模式
|
||||
|
||||
:::warning
|
||||
For this mode to work properly the [Basic Setup](#basic-setup) must've already been completed!
|
||||
:::
|
||||
|
||||
The basic setup already covers the minimum setup required to use the rover in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode).
|
||||
|
||||
This mode is also affected by (optional) acceleration/deceleration limits.
|
||||
As configuration of these limits becomes mandatory for subsequent modes, we do this setup here.
|
||||
|
||||
Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RA_WHEEL_BASE](#RA_WHEEL_BASE) [m]: Measure the distance from the back to the front wheels.
|
||||
|
||||
2. [RA_MAX_STR_ANG](#RA_MAX_STR_ANG) [deg]: Measure the maximum steering angle.
|
||||
|
||||
|
||||
|
||||
3. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: Drive the rover at full throttle and set this parameter to the observed value of the ground speed.
|
||||
|
||||
:::info
|
||||
This parameter is also used for the feed-forward term of the speed control.
|
||||
It will be further tuned in the configuration of [Position mode](#position-mode).
|
||||
|
||||
:::
|
||||
|
||||
4. (Optional) [RO_ACCEL_LIM](#RO_ACCEL_LIM) [m/s^2]: Maximum acceleration you want to allow for your rover.
|
||||
|
||||
<a id="RO_ACCEL_LIM_CONSIDERATIONS"></a>
|
||||
|
||||
:::tip
|
||||
Your rover has a maximum possible acceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. From a standstill, give the rover full throttle until it reaches the maximum speed.
|
||||
2. Disarm the rover and plot the `measured_speed_body_x` from [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md).
|
||||
3. Divide the maximum speed by the time it took to reach it and set this as the value for [RO_ACCEL_LIM](#RO_ACCEL_LIM).
|
||||
|
||||
Some RC rovers have enough torque to lift up if the maximum acceleration is not limited.
|
||||
If that is the case:
|
||||
|
||||
1. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to a low value, give the rover full throttle from a standstill and observe its behaviour.
|
||||
2. Increase [RO_ACCEL_LIM](#RO_ACCEL_LIM) until the rover starts to lift up during the acceleration.
|
||||
3. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
:::
|
||||
|
||||
5. (Optional) [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2]: Maximum deceleration you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
The same [considerations](#RO_ACCEL_LIM_CONSIDERATIONS) as in the configuration of [RO_ACCEL_LIM](#RO_ACCEL_LIM) apply.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
This parameter is also used for the calculation of the speed setpoint during [Auto modes](#auto-modes).
|
||||
|
||||
:::
|
||||
|
||||
6. (Optional) [RA_STR_RATE_LIM](#RA_STR_RATE_LIM) [deg/s]: Maximum steering rate you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
This value depends on your rover and use case.
|
||||
For bigger rovers there might be a mechanical limit that is easy to identify by steering the rover at a standstill and increasing
|
||||
[RA_STR_RATE_LIM](#RA_STR_RATE_LIM) until you observe the steering rate to no longer be limited by the parameter.
|
||||
For smaller rovers you might observe the steering to be too aggressive. Set [RA_STR_RATE_LIM](#RA_STR_RATE_LIM) to a low value and steer the rover at a standstill.
|
||||
Increase the parameter until you reach the maximum steering rate you are comfortable with.
|
||||
|
||||
:::
|
||||
|
||||
:::warning
|
||||
A low maximum steering rate makes the rover worse at tracking steering setpoints, which can lead to a poor performance in the subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
## Acro Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Manual mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
To set up [Acro mode](../flight_modes_rover/ackermann.md#acro-mode) configure the following [parameters](../advanced_config/parameters.md) in QGroundControl:
|
||||
|
||||
1. [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM): Maximum yaw rate you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
Limiting the yaw rate is necessary if the rover is prone rolling over, loosing traction at high speeds or if passenger comfort is important.
|
||||
Small rovers especially can be prone to rolling over when steering aggressively at high speeds.
|
||||
|
||||
If this is the case:
|
||||
|
||||
1. In [Acro mode](../flight_modes_rover/ackermann.md#acro-mode), set [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) to a small value and drive the rover at full throttle and with the right stick all the way to the left or right.
|
||||
2. Increase [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) until the wheels of the rover start to lift up.
|
||||
3. Set [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
If you see no need to limit the yaw rate, set this parameter to the maximum yaw rate the rover can achieve:
|
||||
|
||||
1. In [Manual mode](#manual-mode) drive the rover at full throttle and with the maximum steering angle.
|
||||
2. Plot the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and enter the highest observed value for [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM).
|
||||
|
||||
|
||||
:::
|
||||
|
||||
2. [RO_YAW_RATE_P](#RO_YAW_RATE_P) [-]: Proportional gain of the closed loop yaw rate controller.
|
||||
The closed loop acceleration control will compare the yaw rate setpoint with the measured yaw rate and adapt the motor commands based on the error between them.
|
||||
The proportional gain is multiplied with this error and that value is added to the motor command.
|
||||
This compensates for disturbances such as uneven ground and external forces.
|
||||
|
||||
:::tip
|
||||
To tune this parameter:
|
||||
|
||||
1. Put the rover in [Acro mode](../flight_modes_rover/ackermann.md#acro-mode) and hold the throttle stick and the right stick at a few different levels for a couple of seconds each.
|
||||
2. Disarm the rover and from the flight log plot the `adjusted_yaw_rate_setpoint` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
3. Increase [RO_YAW_RATE_P](#RO_YAW_RATE_P) if the measured value does not track the setpoint fast enough or decrease it if the measurement overshoots the setpoint by too much.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_YAW_RATE_I](#RO_YAW_RATE_I) [-]: Integral gain of the closed loop yaw rate controller.
|
||||
The integral gain accumulates the error between the desired and actual yaw rate scaled by the integral gain over time and that value is added to the motor command.
|
||||
|
||||
::: tip
|
||||
An integrator might not be necessary at this stage, but it will become important for subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Acro mode](../flight_modes_rover/ackermann.md#acro-mode).
|
||||
|
||||
## Stabilized Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Acro mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
For [Stabilized mode](../flight_modes_rover/differential.md#stabilized-mode) the controller utilizes a closed loop yaw controller, which creates a yaw rate setpoint to control the yaw when it is active:
|
||||
|
||||
|
||||
|
||||
Unlike the closed loop yaw rate, this controller has no feed-forward term.
|
||||
Therefore you only need to tune the closed loop gains:
|
||||
|
||||
1. [RO_YAW_P](#RO_YAW_P) [-]: Proportional gain for the closed loop yaw controller.
|
||||
|
||||
::: tip
|
||||
In stabilized mode the closed loop yaw control is only active when driving a straight line (no yaw rate input).
|
||||
To tune it start with a value of 1 for [RO_YAW_P](#RO_YAW_P).
|
||||
Put the rover into stabilized mode and move the left stick of your controller up to drive forwards.
|
||||
Disarm the rover and from the flight log plot the `measured_yaw` and the `adjusted_yaw_setpoint` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) message over each other.
|
||||
Increase/Decrease the parameter until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
For the closed loop yaw control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
Since the yaw and yaw rate controllers are cascaded, there only needs to be one integrator which is in the yaw rate controller. If you observe a steady state error in the yaw setpoint increase the [RO_YAW_RATE_I](#RO_YAW_RATE_I) parameter.
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Stabilized mode](../flight_modes_rover/ackermann.md#stabilized-mode).
|
||||
|
||||
## Position Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Stabilized mode](#stabilized-mode) must already be configured!
|
||||
:::
|
||||
|
||||
[Position mode](../flight_modes_rover/ackermann.md#position-mode) is the most advanced manual mode, utilizing closed loop yaw rate and speed control and leveraging position estimates.
|
||||
|
||||
To configure set the following parameters:
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM) [m/s]: This is the maximum speed you want to allow for your rover.
|
||||
This will define the stick-to-speed mapping for position mode and set an upper limit for the speed setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop speed control which linearly maps desired speeds to normalized motor commands.
|
||||
As mentioned in the [Manual mode](../flight_modes_rover/ackermann.md#manual-mode) configuration , a good starting point is the observed ground speed when the rover drives at maximum throttle in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode).
|
||||
|
||||
<a id="RA_SPEED_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter:
|
||||
|
||||
1. Set [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I) to zero.
|
||||
This way the speed is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and then move the left stick of your controller up and/or down and hold it at a few different levels for a couple of seconds each.
|
||||
3. Disarm the rover and from the flight log plot the `adjusted_speed_body_x_setpoint` and the `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
4. If the actual speed of the rover is higher than the speed setpoint, increase [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
::: info
|
||||
If your rover oscillates when driving a straight line in [Position mode](../flight_modes_rover/ackermann.md#position-mode), set this parameter to the observed ground speed at maximum throttle in [Manual mode](../flight_modes_rover/ackermann.md#manual-mode) and complete steps 5-7 first before continuing the tuning of the closed loop speed control (Steps 2-4).
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_SPEED_P](#RO_SPEED_P) [-]: Proportional gain of the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RO_MAX_THR_SPEED](#RA_SPEED_TUNING).
|
||||
If you tuned [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_SPEED_I](#RO_SPEED_I) [-]: Integral gain for the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
For the closed loop speed control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
|
||||
:::
|
||||
|
||||
5. [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN): When driving in a straight line (right stick centered) position mode leverages the same path following algorithm used in [auto modes](#auto-modes) called [pure pursuit](#pure-pursuit-guidance-logic) to achieve the best possible straight line driving behaviour ([Illustration of control architecture](#pure_pursuit_controller)).
|
||||
This parameter determines how aggressive the controller will steer towards the path.
|
||||
|
||||
::: tip
|
||||
Decreasing the parameter makes it more aggressive but can lead to oscillations.
|
||||
|
||||
To tune this:
|
||||
|
||||
1. Start with a value of 1 for [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN)
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and while driving a straight line at approximately half the maximum speed observe its behaviour.
|
||||
3. If the rover does not drive in a straight line, reduce the value of the parameter, if it oscillates around the path increase the value.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
6. [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN): Minimum threshold for the lookahead distance used by the [pure pursuit algorithm](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and drive at very low speeds, if the rover starts to oscillate even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then increase the value of [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
:::
|
||||
|
||||
7. [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX): Maximum threshold for the lookahead distance used by [pure pursuit](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/ackermann.md#position-mode) and drive at very high speeds, if the rover does not drive in a straight line even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then decrease the value of [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Position mode](../flight_modes_rover/ackermann.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
:::warning
|
||||
For auto modes to work properly [Manual Mode](#manual-mode), [Acro mode](#acro-mode)and [Position mode](#position-mode) must already be configured!
|
||||
:::
|
||||
|
||||
<a id="pure_pursuit_controller"></a>
|
||||
|
||||
In [auto modes](../flight_modes_rover/ackermann.md#auto-modes) the autopilot takes over navigation tasks using the following control architecture:
|
||||
|
||||
|
||||
|
||||
The required parameter configuration is discussed in the following sections.
|
||||
|
||||
### Speed
|
||||
|
||||
1. [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2] and [RO_JERK_LIM](#RO_JERK_LIM) [m/s^3] are used to calculate a speed trajectory such that the rover reaches the next waypoint with the correct [cornering speed](#cornering-speed).
|
||||
|
||||
::: tip
|
||||
Plan a mission for the rover to drive a square and observe how it slows down when approaching a waypoint:
|
||||
|
||||
- If the rover decelerates too quickly decrease the [RO_DECEL_LIM](#RO_DECEL_LIM) parameter, if it starts slowing down too early increase the parameter.
|
||||
- If you observe a jerking motion as the rover slows down, decrease the [RO_JERK_LIM](#RO_JERK_LIM) parameter otherwise increase it as much as possible as it can interfere with the tuning of [RO_DECEL_LIM](#RO_DECEL_LIM).
|
||||
|
||||
These two parameters have to be tuned as a pair, repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
2. Plot the `adjusted_speed_body_x_setpoint` and `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I).
|
||||
|
||||
### Corner Cutting
|
||||
|
||||
The module employs a special cornering logic causing the rover to "cut corners" to achieve a smooth trajectory.
|
||||
This is done by scaling the acceptance radius based on the corner the rover has to drive (for geometric explanation see [Cornering logic](#mission-cornering-logic-info-only)).
|
||||
|
||||
|
||||
|
||||
The degree to which corner cutting is allowed can be tuned, or disabled, with the following parameters:
|
||||
|
||||
:::info
|
||||
The corner cutting effect is a tradeoff between how close you get to the waypoint and the smoothness of the trajectory.
|
||||
:::
|
||||
|
||||
1. [NAV_ACC_RAD](#NAV_ACC_RAD) [m]: Default acceptance radius
|
||||
This is also used as a lower bound for the acceptance radius scaling.
|
||||
2. [RA_ACC_RAD_MAX](#RA_ACC_RAD_MAX) [m]: The maximum the acceptance radius can be scaled to.
|
||||
Set equal to [NAV_ACC_RAD](#NAV_ACC_RAD) to disable the corner cutting effect.
|
||||
3. [RA_ACC_RAD_GAIN](#RA_ACC_RAD_GAIN) [-]: This tuning parameter is a multiplicand on the [calculated ideal acceptance radius](#corner-cutting-logic) to account for dynamic effects.
|
||||
|
||||
:::tip
|
||||
Initially set this parameter to `1`.
|
||||
If you observe the rover overshooting the corner, increase this parameter until you are satisfied with the behaviour.
|
||||
Note that the scaling of the acceptance radius is limited by [RA_ACC_RAD_MAX](#RA_ACC_RAD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
### Path Following
|
||||
|
||||
The [pure pursuit](#pure-pursuit-guidance-logic) algorithm is used to calculate a yaw rate setpoint for the vehicle that is then close loop controlled.
|
||||
The close loop yaw rate was tuned in the configuration of the [Acro mode](#acro-mode), and the pure pursuit was tuned when setting up the [Position mode](#position-mode).
|
||||
During any auto navigation task observe the behaviour of the rover.
|
||||
|
||||
If you are unsatisfied with the path following, there are 2 steps to take:
|
||||
|
||||
1. Plot the `adjusted_yaw_rate_setpoint` and the `measured_yaw_rate` from the [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
2. Plot the `adjusted_yaw_setpoint` and the `measured_yaw` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the value for [RO_YAW_P](#RO_YAW_RATE_P) and potentially further tune [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
3. Steps 1 and 2 ensures accurate setpoint tracking, if the path following is still unsatisfactory you need to further tune the [pure pursuit](#pure-pursuit-guidance-logic) parameters.
|
||||
|
||||
## Pure Pursuit Guidance Logic
|
||||
|
||||
The desired yaw setpoints are generated using a pure pursuit algorithm.
|
||||
|
||||
The controller takes the intersection point between a circle around the vehicle and a line segment.
|
||||
In mission mode this line is usually constructed by connecting the previous and current waypoint.
|
||||
|
||||
|
||||
|
||||
The radius of the circle around the vehicle is used to tune the controller and is often referred to as look-ahead distance.
|
||||
|
||||
The look-ahead distance sets how aggressive the controller behaves and is defined as $l_d = v \cdot k$.
|
||||
It depends on the velocity $v$ of the rover and a tuning parameter $k$ that can be set with the parameter [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN).
|
||||
|
||||
:::info
|
||||
A lower value of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) makes the controller more aggressive but can lead to oscillations!
|
||||
:::
|
||||
|
||||
The lookahead is constrained between [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX) and [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
If the distance from the path to the rover is bigger than the lookahead distance, the rover will target the point on the path that is closest to the rover.
|
||||
|
||||
To summarize, the following parameters can be used to tune the controller:
|
||||
|
||||
| 参数 | 描述 | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | ---- |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius | m |
|
||||
|
||||
## Mission Cornering Logic (Info only)
|
||||
|
||||
### Corner Cutting Logic
|
||||
|
||||
To enable a smooth trajectory, the acceptance radius of waypoints is scaled based on the angle between a line segment from the current-to-previous and current-to-next waypoints.
|
||||
The ideal trajectory would be to arrive at the next line segment with the heading pointing towards the next waypoint.
|
||||
For this purpose the minimum turning circle of the rover is inscribed tangentially to both line segments.
|
||||
|
||||
|
||||
|
||||
The acceptance radius of the waypoint is set to the distance from the waypoint to the tangential points between the circle and the line segments:
|
||||
|
||||
$$
|
||||
\begin{align*}
|
||||
r_{min} &= \frac{L}{\sin\left( \delta_{max}\right) } \\
|
||||
\theta &= \frac{1}{2}\arccos\left( \frac{\vec{a}*\vec{b}}{|\vec{a}||\vec{b}|}\right) \\
|
||||
r_{acc} &= \frac{r_{min}}{\tan\left( \theta\right) }
|
||||
\end{align*}
|
||||
$$
|
||||
|
||||
| Symbol | 描述 | Unit |
|
||||
| ----------------------------------- | ---------------------------------- | ---- |
|
||||
| $\vec{a}$ | Vector from current to previous WP | m |
|
||||
| $\vec{b}$ | Vector from current to next WP | m |
|
||||
| $r_{min}$ | Minimum turn radius | m |
|
||||
| $\delta_{max}$ | Maximum steer angle | m |
|
||||
| $r_{acc}$ | Acceptance radius | m |
|
||||
|
||||
### Cornering Speed
|
||||
|
||||
To smoothen the trajectory further and reduce the risk of the rover rolling over, the rover speed is regulated as follows:
|
||||
|
||||
1. During cornering the rover drives at the following speed:
|
||||
|
||||
<!-- prettier-ignore -->
|
||||
|
||||
$$v_{cor, max} = \dot{\psi}_{max} \cdot r$$
|
||||
|
||||
with $r:$ Turning radius for the upcoming corner and $\dot{\psi}_{max}:$ Maximum yaw rate ([RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM)).
|
||||
|
||||
2. In between waypoints (straight line) the rover speed is regulated such that it will arrive at the acceptance radius of the waypoint with the desired cornering speed.
|
||||
|
||||
The rover is constrained between the maximum speed [RO_SPEED_LIM](#RO_SPEED_LIM) and the speed where the maximum steering angle does not cause the rover to exceed the yaw rate limit:
|
||||
|
||||
<!-- prettier-ignore -->
|
||||
|
||||
$$v_{min} = \frac{w_b \cdot \dot{\psi}_{max}}{tan(\delta_{max})}$$
|
||||
|
||||
with $w_b:$ Wheel base ([RA_WHEEL_BASE](#RA_WHEEL_BASE)), $\dot{\psi}_{max}:$ Maximum yaw rate ([RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM)) and $\delta_{max}:$ Maximum steering angle ([RA_MAX_STR_ANG](#RA_MAX_STR_ANG)).
|
||||
|
||||
## Parameter Overview
|
||||
|
||||
List of all parameters of the ackermann rover module:
|
||||
|
||||
| 参数 | 描述 | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------- | ------- |
|
||||
| <a id="RA_WHEEL_BASE"></a>[RA_WHEEL_BASE](../advanced_config/parameter_reference.md#RA_WHEEL_BASE) | Wheel base | m |
|
||||
| <a id="RA_MAX_STR_ANG"></a>[RA_MAX_STR_ANG](../advanced_config/parameter_reference.md#RA_MAX_STR_ANG) | Maximum steering angle | deg |
|
||||
| <a id="RO_MAX_THR_SPEED"></a>[RO_MAX_THR_SPEED](../advanced_config/parameter_reference.md#RO_MAX_THR_SPEED) | Speed the rover drives at maximum throttle | m/s |
|
||||
| <a id="RO_YAW_RATE_LIM"></a>[RO_YAW_RATE_LIM](../advanced_config/parameter_reference.md#RO_YAW_RATE_LIM) | Maximum allowed yaw rate | m/s^2 |
|
||||
| <a id="RO_YAW_RATE_P"></a>[RO_YAW_RATE_P](../advanced_config/parameter_reference.md#RO_YAW_RATE_P) | Proportional gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_RATE_I"></a>[RO_YAW_RATE_I](../advanced_config/parameter_reference.md#RO_YAW_RATE_I) | Integral gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_P"></a>[RO_YAW_P](../advanced_config/parameter_reference.md#RO_YAW_P) | Proportional gain for yaw controller | - |
|
||||
| <a id="RO_SPEED_LIM"></a>[RO_SPEED_LIM](../advanced_config/parameter_reference.md#RO_SPEED_LIM) | Maximum allowed speed | m/s |
|
||||
| <a id="RO_SPEED_P"></a>[RO_SPEED_P](../advanced_config/parameter_reference.md#RO_SPEED_P) | Proportional gain for speed controller | - |
|
||||
| <a id="RO_SPEED_I"></a>[RO_SPEED_I](../advanced_config/parameter_reference.md#RO_SPEED_I) | Integral gain for speed controller | - |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter for pure pursuit | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="NAV_ACC_RAD"></a>[NAV_ACC_RAD](../advanced_config/parameter_reference.md#NAV_ACC_RAD) | Default acceptance radius | m |
|
||||
| <a id="RA_STR_RATE_LIM"></a>[RA_STR_RATE_LIM](../advanced_config/parameter_reference.md#RA_STR_RATE_LIM) | (Optional) Maximum allowed steering rate | deg/s |
|
||||
| <a id="RO_ACCEL_LIM"></a>[RO_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_ACCEL_LIM) | (Optional) Maximum allowed acceleration | m/s^2 |
|
||||
| <a id="RO_DECEL_LIM"></a>[RO_DECEL_LIM](../advanced_config/parameter_reference.md#RO_DECEL_LIM) | (Optional) Maximum allowed deceleration | m/s^2 |
|
||||
| <a id="RO_JERK_LIM"></a>[RO_JERK_LIM](../advanced_config/parameter_reference.md#RO_JERK_LIM) | (Optional) Maximum allowed jerk | $m/s^3$ |
|
||||
| <a id="RA_ACC_RAD_MAX"></a>[RA_ACC_RAD_MAX](../advanced_config/parameter_reference.md#RA_ACC_RAD_MAX) | (Optional) Maximum radius the acceptance radius can be scaled to | m |
|
||||
| <a id="RA_ACC_RAD_GAIN"></a>[RA_ACC_RAD_GAIN](../advanced_config/parameter_reference.md#RA_ACC_RAD_GAIN) | (Optional) Tuning parameter for the acceptance radius scaling | - |
|
||||
|
||||
## See Also
|
||||
|
||||
- [Drive Modes (Ackermann Rover)](../flight_modes_rover/ackermann.md).
|
||||
@@ -1,395 +0,0 @@
|
||||
# Configuration/Tuning (Differential Rover)
|
||||
|
||||
This topic provides a step-by-step guide for setting up your [Differential rover](../frames_rover/differential.md).
|
||||
Successive steps enable [drive modes](../flight_modes_rover/differential.md) with more autopilot support and features.
|
||||
|
||||
:::warning
|
||||
Each step is dependent on the previous steps having been completed.
|
||||
Modes will only work properly if the preceding modes have been configured.
|
||||
:::
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To configure the differential rover frame and outputs:
|
||||
|
||||
1. Enable Rover support by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
Note that this is a special build that contains rover-specific modules.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select _Generic Rover Differential_ frame:
|
||||
|
||||
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe is not displayed and you have checked that you are using rover firmware (not the default), you can alternatively enable this frame by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `50000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Use [Actuators Configuration & Testing](../config/actuators.md) to map the motor functions to flight controller outputs.
|
||||
|
||||
## 手动模式
|
||||
|
||||
:::warning
|
||||
For this mode to work properly the [Basic Setup](#basic-setup) must've already been completed!
|
||||
:::
|
||||
|
||||
The basic setup already covers the minimum setup required to use the rover in [Manual mode](../flight_modes_rover/differential.md#manual-mode).
|
||||
|
||||
This mode is also affected by (optional) acceleration/deceleration limits.
|
||||
As configuration of these limits becomes mandatory for subsequent modes, we do this setup here.
|
||||
|
||||
Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RD_WHEEL_TRACK](#RD_WHEEL_TRACK) [m]: Measure the distance from the centre of the right wheel to the centre of the left wheel.
|
||||
|
||||
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: Drive the rover at full throttle and set this parameter to the observed value of the ground speed.
|
||||
|
||||
:::info
|
||||
This parameter is also used for the feed-forward term of the speed control.
|
||||
It will be further tuned in the configuration of [Position mode](#position-mode).
|
||||
|
||||
:::
|
||||
|
||||
3. (Optional) [RO_ACCEL_LIM](#RO_ACCEL_LIM) [m/s^2]: Maximum acceleration you want to allow for your rover.
|
||||
|
||||
<a id="RO_ACCEL_LIM_CONSIDERATIONS"></a>
|
||||
|
||||
:::tip
|
||||
Your rover has a maximum possible acceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. From a standstill, give the rover full throttle until it reaches the maximum speed.
|
||||
2. Disarm the rover and plot the `measured_speed_body_x` from [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md).
|
||||
3. Divide the maximum speed by the time it took to reach it and set this as the value for [RO_ACCEL_LIM](#RO_ACCEL_LIM).
|
||||
|
||||
Some RC rovers have enough torque to lift up if the maximum acceleration is not limited.
|
||||
If that is the case:
|
||||
|
||||
4. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to a low value, give the rover full throttle from a standstill and observe its behaviour.
|
||||
5. Increase [RO_ACCEL_LIM](#RO_ACCEL_LIM) until the rover starts to lift up during the acceleration.
|
||||
6. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
4. (Optional) [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2]: Maximum deceleration you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
The same [considerations](#RO_ACCEL_LIM_CONSIDERATIONS) as in the configuration of [RO_ACCEL_LIM](#RO_ACCEL_LIM) apply.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
This parameter is also used for the calculation of the speed setpoint during [Auto modes](#auto-modes).
|
||||
|
||||
:::
|
||||
|
||||
## Acro Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Manual mode](#manual-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
To set up [Acro mode](../flight_modes_rover/differential.md#acro-mode), navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) [deg/s]: This is the maximum yaw rate you want to allow for your rover.
|
||||
This will define the stick-to-yaw-rate mapping for all manual modes using closed loop yaw control and set an upper limit for the yaw rate setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RD_MAX_THR_YAW_R](#RD_MAX_THR_YAW_R) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop yaw rate control.
|
||||
The controller calculates the required speed difference between the left and right motor to achieve the desired yaw rate.
|
||||
This desired speed difference is then linearly mapped to normalized motor commands.
|
||||
To get a good starting value for this parameter drive the rover in manual mode forwards at full throttle and note the ground speed of the vehicle.
|
||||
Then enter _half_ this value for the parameter. <a id="RD_YAW_RATE_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter, first make sure you set [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I) to zero.
|
||||
This way the yaw rate is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
Now put the rover in [Acro mode](../flight_modes_rover/differential.md#acro-mode) and then move the right-stick of your controller to the right and/or left and hold it at a few different levels for a couple of seconds each.
|
||||
Disarm the rover and from the flight log plot the `adjusted_yaw_rate_setpoint` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the actual yaw rate of the rover is higher than the yaw rate setpoint, increase [RD_MAX_THR_YAW_R](#RD_MAX_THR_YAW_R).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_YAW_RATE_P](#RO_YAW_RATE_P) [-]: Proportional gain of the closed loop yaw rate controller.
|
||||
Unlike the feed-forward part of the controller, the closed loop yaw rate control will compare the yaw rate setpoint with the measured yaw rate and adapt to motor commands based on the error between them.
|
||||
The proportional gain is multiplied with this error and that value is added to the motor command.
|
||||
This compensates for disturbances such as uneven ground and external forces.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RD_MAX_THR_YAW_R](#RD_YAW_RATE_P_TUNING).
|
||||
If you tuned [RD_MAX_THR_YAW_R](#RD_MAX_THR_YAW_R) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_YAW_RATE_I](#RO_YAW_RATE_I) [-]: Integral gain of the closed loop yaw controller.
|
||||
The integral gain accumulates the error between the desired and actual yaw rate scaled by the integral gain over time and that value is added to the motor command.
|
||||
|
||||
::: tip
|
||||
An integrator might not be neccessary at this stage, but it will become important for subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
5. (Optional) [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM) and [RO_YAW_DECEL_LIM](#RO_YAW_DECEL_LIM) [deg/s^2]:
|
||||
This is the maximum yaw acceleration and deceleration you want to allow for your rover.
|
||||
This can be used to smooth the `yaw_rate` setpoints and make their trajectory feasible based on the physical limitations of the rover.
|
||||
It also improves tracking and avoid integrator build up.
|
||||
|
||||
::: tip
|
||||
Your rover has a maximum possible yaw acceleration/deceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. Put the rover into [Manual mode](../flight_modes_rover/differential.md#manual-mode).
|
||||
2. From a standstill, move the right stick all the way to the right or left until the rover reaches the maximum yaw rate then return the right stick to the middle.
|
||||
3. Disarm the rover and plot the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md).
|
||||
4. Divide the maximum yaw rate by the time it took to reach it and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
5. Divide the maximum yaw rate by the time it took to return to a standstill and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Acro mode](../flight_modes_rover/differential.md#acro-mode).
|
||||
|
||||
## Stabilized Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Acro mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
For [Stabilized mode](../flight_modes_rover/differential.md#stabilized-mode) the controller utilizes a closed loop yaw controller, which creates a yaw rate setpoint to control the yaw when it is active:
|
||||
|
||||
|
||||
|
||||
Unlike the closed loop yaw rate, this controller has no feed-forward term.
|
||||
Therefore you only need to tune the closed loop gains:
|
||||
|
||||
1. [RO_YAW_P](#RO_YAW_P) [-]: Proportional gain for the closed loop yaw controller.
|
||||
|
||||
::: tip
|
||||
In stabilized mode the closed loop yaw control is only active when driving a straight line (no yaw rate input).
|
||||
|
||||
1. Start with a value of 1 for [RO_YAW_P](#RO_YAW_P).
|
||||
2. Put the rover into stabilized mode and move the left stick of your controller up and/or down to drive forwards/backwards.
|
||||
3. Disarm the rover and from the flight log plot the `measured_yaw` and the `adjusted_yaw_setpoint` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) message over each other.
|
||||
4. Increase/Decrease the parameter until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
For the closed loop yaw control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
Since the yaw and yaw rate controllers are cascaded, there only needs to be one integrator which is in the yaw rate controller.
|
||||
If you observe a steady state error in the yaw setpoint increase the [RO_YAW_RATE_I](#RO_YAW_RATE_I) parameter.
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Stabilized mode](../flight_modes_rover/differential.md#stabilized-mode).
|
||||
|
||||
## Position Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Stabilized mode](#stabilized-mode) must already be configured!
|
||||
:::
|
||||
|
||||
[Position mode](../flight_modes_rover/differential.md#position-mode) is the most advanced manual mode, utilizing closed loop yaw rate, yaw and speed control and leveraging position estimates.
|
||||
|
||||
To configure set the following parameters:
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM) [m/s]: This is the maximum speed you want to allow for your rover.
|
||||
This will define the stick-to-speed mapping for position mode and set an upper limit for the speed setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop speed control which linearly maps desired speeds to normalized motor commands.
|
||||
A good starting point is the observed ground speed when the rover drives at maximum throttle in [Manual mode](../flight_modes_rover/differential.md#manual-mode).
|
||||
|
||||
<a id="RD_SPEED_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter:
|
||||
|
||||
1. Set [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I) to zero.
|
||||
This way the speed is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and then move the left stick of your controller up and/or down and hold it at a few different levels for a couple of seconds each.
|
||||
3. Disarm the rover and from the flight log plot the `adjusted_speed_body_x_setpoint` and the `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
4. If the actual speed of the rover is higher than the speed setpoint, increase [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
::: info
|
||||
If your rover oscillates when driving a straight line in [Position mode](../flight_modes_rover/differential.md#position-mode) just set this parameter to the observed ground speed at maximum throttle in [Manual mode](../flight_modes_rover/differential.md#manual-mode) and complete steps 5-7 first before continuing the tuning of the closed loop speed control (Steps 2-4).
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_SPEED_P](#RO_SPEED_P) [-]: Proportional gain of the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RO_MAX_THR_SPEED](#RD_SPEED_P_TUNING).
|
||||
If you tuned [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_SPEED_I](#RO_SPEED_I) [-]: Integral gain for the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
For the closed loop speed control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
|
||||
:::
|
||||
|
||||
5. [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN): When driving in a straight line (no yaw rate input) position mode leverages the same path following algorithm used in [auto modes](#auto-modes) called [pure pursuit](#pure-pursuit-guidance-logic) to achieve the best possible straight line driving behaviour ([Illustration of control architecture](#pure_pursuit_controller)).
|
||||
This parameter determines how aggressive the controller will steer towards the path.
|
||||
|
||||
::: tip
|
||||
Decreasing the parameter makes it more aggressive but can lead to oscillations.
|
||||
|
||||
To tune this:
|
||||
|
||||
1. Start with a value of 1 for [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN)
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and while driving a straight line at approximately half the maximum speed observe its behaviour.
|
||||
3. If the rover does not drive in a straight line, reduce the value of the parameter, if it oscillates around the path increase the value.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
6. [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN): Minimum threshold for the lookahead distance used by the [pure pursuit algorithm](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and drive at very low speeds, if the rover starts to oscillate even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then increase the value of [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
:::
|
||||
|
||||
7. [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX): Maximum threshold for the lookahead distance used by [pure pursuit](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/differential.md#position-mode) and drive at very high speeds, if the rover does not drive in a straight line even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then decrease the value of [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Position mode](../flight_modes_rover/differential.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Position mode](#position-mode) must already be configured!
|
||||
:::
|
||||
|
||||
<a id="pure_pursuit_controller"></a>
|
||||
In [auto modes](../flight_modes_rover/differential.md#auto-modes) the autopilot takes over navigation tasks using the following control architecture:
|
||||
|
||||
|
||||
|
||||
The required parameters are separated into the following sections:
|
||||
|
||||
### Speed
|
||||
|
||||
These parameters are used to calculate the speed setpoint in auto modes:
|
||||
|
||||
1. [RO_DECEL_LIM](#RO_DECEL_LIM) ($m/s^2$) and [RO_JERK_LIM](#RO_JERK_LIM) ($m/s^3$) are used to calculate a velocity trajectory such that the rover comes to a smooth stop as it reaches a waypoint.
|
||||
|
||||
::: tip
|
||||
Plan a mission for the rover to drive a square and observe how it slows down when approaching a waypoint:
|
||||
|
||||
- If the rover decelerates too quickly decrease the [RO_DECEL_LIM](#RO_DECEL_LIM) parameter, if it starts slowing down too early increase the parameter.
|
||||
- If you observe a jerking motion as the rover slows down, decrease the [RO_JERK_LIM](#RO_JERK_LIM) parameter otherwise increase it as much as possible as it can interfere with the tuning of [RO_DECEL_LIM](#RO_DECEL_LIM).
|
||||
|
||||
These two parameters have to be tuned as a pair, repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
2. Plot the `adjusted_speed_body_x_setpoint` and `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I).
|
||||
|
||||
The rover only slows down when approaching the waypoint if the angle between the line segment between the previous/current waypoint and current/next waypoint is smaller than 180° - [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN).
|
||||
In other words: The rover slows down only if the expected heading error towards the next waypoint when arriving at the current waypoint is below [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN).
|
||||
|
||||
|
||||
|
||||
For more information on the [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN) parameter see [State Machine](#state-machine).
|
||||
|
||||
### State Machine
|
||||
|
||||
The module employs the following state machine to make full use of a differential rovers ability to turn on the spot:
|
||||
|
||||
|
||||
|
||||
These transition thresholds can be set with [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN) and [RD_TRANS_TRN_DRV](#RD_TRANS_TRN_DRV).
|
||||
|
||||
### Path Following
|
||||
|
||||
The [pure pursuit](#pure-pursuit-guidance-logic) algorithm is used to calculate a desired yaw for the vehicle that is then close loop controlled.
|
||||
The close loop yaw rate was tuned in the configuration of the [Stabilized mode](#stabilized-mode) and the pure pursuit was tuned when setting up the [Position mode](#position-mode).
|
||||
During any auto navigation task observe the behaviour of the rover.
|
||||
If you are unsatisfied with the path following, there are 3 steps to take:
|
||||
|
||||
1. Plot the `adjusted_yaw_rate_setpoint` and the `measured_yaw_rate` from the [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
2. Plot the `adjusted_yaw_setpoint` and the `measured_yaw` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the value for [RO_YAW_P](#RO_YAW_RATE_P) and potentially further tune [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
3. Steps 1 and 2 ensures accurate setpoint tracking, if the path following is still unsatisfactory you need to further tune the [pure pursuit](#pure-pursuit-guidance-logic) parameters.
|
||||
|
||||
## Pure Pursuit Guidance Logic
|
||||
|
||||
The desired yaw setpoints are generated using a pure pursuit algorithm:
|
||||
The controller takes the intersection point between a circle around the vehicle and a line segment.
|
||||
In mission mode this line is usually constructed by connecting the previous and current waypoint:
|
||||
|
||||
|
||||
|
||||
The radius of the circle around the vehicle is used to tune the controller and is often referred to as look-ahead distance.
|
||||
|
||||
The look ahead distance sets how aggressive the controller behaves and is defined as $l_d = v \cdot k$.
|
||||
It depends on the velocity $v$ of the rover and a tuning parameter $k$ that can be set with the parameter [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN).
|
||||
|
||||
:::info
|
||||
A lower value of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) makes the controller more aggressive but can lead to oscillations!
|
||||
:::
|
||||
|
||||
The lookahead is constrained between [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX) and [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
If the distance from the path to the rover is bigger than the lookahead distance, the rover will target the point on the path that is closest to the rover.
|
||||
|
||||
To summarize, the following parameters can be used to tune the controller:
|
||||
|
||||
| 参数 | 描述 | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | ---- |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius | m |
|
||||
|
||||
## Parameter Overview
|
||||
|
||||
List of all parameters of the differential rover module:
|
||||
|
||||
| 参数 | 描述 | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- | ------- |
|
||||
| <a id="RD_WHEEL_TRACK"></a>[RD_WHEEL_TRACK](../advanced_config/parameter_reference.md#RD_WHEEL_TRACK) | Wheel track | m |
|
||||
| <a id="RD_MAX_THR_YAW_R"></a>[RD_MAX_THR_YAW_R](../advanced_config/parameter_reference.md#RD_MAX_THR_YAW_R) | Yaw rate turning left/right wheels at max speed in opposite directions | m/s |
|
||||
| <a id="RD_TRANS_DRV_TRN"></a>[RD_TRANS_DRV_TRN](../advanced_config/parameter_reference.md#RD_TRANS_DRV_TRN) | Heading error threshold to switch from driving to spot turning | deg |
|
||||
| <a id="RD_TRANS_TRN_DRV"></a>[RD_TRANS_TRN_DRV](../advanced_config/parameter_reference.md#RD_TRANS_TRN_DRV) | Heading error threshold to switch from spot turning to driving | deg |
|
||||
| <a id="RD_MISS_SPD_GAIN"></a>[RD_MISS_SPD_GAIN](../advanced_config/parameter_reference.md#RD_MISS_SPD_GAIN) | Tuning parameter for the speed reduction during waypoint transition | m/s |
|
||||
| <a id="RO_YAW_RATE_LIM"></a>[RO_YAW_RATE_LIM](../advanced_config/parameter_reference.md#RO_YAW_RATE_LIM) | Maximum allowed yaw rate for the rover | deg/s |
|
||||
| <a id="RO_YAW_RATE_P"></a>[RO_YAW_RATE_P](../advanced_config/parameter_reference.md#RO_YAW_RATE_P) | Proportional gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_RATE_I"></a>[RO_YAW_RATE_I](../advanced_config/parameter_reference.md#RO_YAW_RATE_I) | Integral gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_P"></a>[RO_YAW_P](../advanced_config/parameter_reference.md#RO_YAW_P) | Proportional gain for yaw controller | - |
|
||||
| <a id="RO_MAX_THR_SPEED"></a>[RO_MAX_THR_SPEED](../advanced_config/parameter_reference.md#RO_MAX_THR_SPEED) | Speed the rover drives at maximum throttle | m/s |
|
||||
| <a id="RO_SPEED_P"></a>[RO_SPEED_P](../advanced_config/parameter_reference.md#RO_SPEED_P) | Proportional gain for speed controller | - |
|
||||
| <a id="RO_SPEED_I"></a>[RO_SPEED_I](../advanced_config/parameter_reference.md#RO_SPEED_I) | Integral gain for speed controller | - |
|
||||
| <a id="RO_SPEED_LIM"></a>[RO_SPEED_LIM](../advanced_config/parameter_reference.md#RO_SPEED_LIM) | Maximum allowed speed for the rover (and default mission speed). | m/s |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter for pure pursuit | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="RO_ACCEL_LIM"></a>[RO_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_ACCEL_LIM) | (Optional) Maximum allowed acceleration | m/s^2 |
|
||||
| <a id="RO_DECEL_LIM"></a>[RO_DECEL_LIM](../advanced_config/parameter_reference.md#RO_DECEL_LIM) | (Optional) Maximum allowed deceleration | m/s^2 |
|
||||
| <a id="RO_JERK_LIM"></a>[RO_JERK_LIM](../advanced_config/parameter_reference.md#RO_JERK_LIM) | (Optional) Maximum allowed jerk | $m/s^3$ |
|
||||
| <a id="RO_YAW_ACCEL_LIM"></a>[RO_YAW_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_ACCEL_LIM) | (Optional) Maximum allowed yaw acceleration | m/s^2 |
|
||||
| <a id="RO_YAW_DECEL_LIM"></a>[RO_YAW_DECEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_DECEL_LIM) | (Optional) Maximum allowed yaw deceleration | m/s^2 |
|
||||
|
||||
## See Also
|
||||
|
||||
- [Drive Modes (Differential Rover)](../flight_modes_rover/differential.md).
|
||||
@@ -1,396 +0,0 @@
|
||||
# Configuration/Tuning (Mecanum Rover)
|
||||
|
||||
This topic provides a step-by-step guide for setting up your [Mecanum rover](../frames_rover/mecanum.md).
|
||||
Successive steps enable [drive modes](../flight_modes_rover/mecanum.md) with more autopilot support and features.
|
||||
|
||||
:::warning
|
||||
Each step is dependent on the previous steps having been completed.
|
||||
Modes will only work properly if the preceding modes have been configured.
|
||||
:::
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To start using the mecanum rover:
|
||||
|
||||
1. Enable Rover support by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
Note that this is a special build that contains rover-specific modules.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select _Generic Rover Mecanum_ frame:
|
||||
|
||||
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe does not show up in the UI, it can alternatively be selected by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `52000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Use [Actuators Configuration & Testing](../config/actuators.md) to map the motor functions to flight controller outputs.
|
||||
|
||||
## 手动模式
|
||||
|
||||
:::warning
|
||||
For this mode to work properly the [Basic Setup](#basic-setup) must've already been completed!
|
||||
:::
|
||||
|
||||
The basic setup already covers the minimum setup required to use the rover in [Manual mode](../flight_modes_rover/mecanum.md#manual-mode).
|
||||
|
||||
This mode is also affected by (optional) acceleration/deceleration limits.
|
||||
As configuration of these limits becomes mandatory for subsequent modes, we do this setup here.
|
||||
|
||||
Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RM_WHEEL_TRACK](#RM_WHEEL_TRACK) [m]: Measure the distance from the centre of the right wheel to the centre of the left wheel.
|
||||
|
||||
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: Drive the rover at full throttle and set this parameter to the observed value of the ground speed.
|
||||
|
||||
:::info
|
||||
This parameter is also used for the feed-forward term of the speed control.
|
||||
It will be further tuned in the configuration of [Position mode](#position-mode).
|
||||
|
||||
:::
|
||||
|
||||
3. (Optional) [RO_ACCEL_LIM](#RO_ACCEL_LIM) [m/s^2]: Maximum acceleration you want to allow for your rover.
|
||||
|
||||
<a id="RO_ACCEL_LIM_CONSIDERATIONS"></a>
|
||||
|
||||
:::tip
|
||||
Your rover has a maximum possible acceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. From a standstill, give the rover full throttle until it reaches the maximum speed.
|
||||
2. Disarm the rover and plot the `measured_speed_body_x` from [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md).
|
||||
3. Divide the maximum speed by the time it took to reach it and set this as the value for [RO_ACCEL_LIM](#RO_ACCEL_LIM).
|
||||
|
||||
Some RC rovers have enough torque to lift up if the maximum acceleration is not limited.
|
||||
If that is the case:
|
||||
|
||||
4. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to a low value, give the rover full throttle from a standstill and observe its behaviour.
|
||||
5. Increase [RO_ACCEL_LIM](#RO_ACCEL_LIM) until the rover starts to lift up during the acceleration.
|
||||
6. Set [RO_ACCEL_LIM](#RO_ACCEL_LIM) to the highest value that does not cause the rover to lift up.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
4. (Optional) [RO_DECEL_LIM](#RO_DECEL_LIM) [m/s^2]: Maximum deceleration you want to allow for your rover.
|
||||
|
||||
:::tip
|
||||
The same [considerations](#RO_ACCEL_LIM_CONSIDERATIONS) as in the configuration of [RO_ACCEL_LIM](#RO_ACCEL_LIM) apply.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
This parameter is also used for the calculation of the speed setpoint during [Auto modes](#auto-modes).
|
||||
|
||||
:::
|
||||
|
||||
## Acro Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Manual mode](#manual-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
To set up [Acro mode](../flight_modes_rover/mecanum.md#acro-mode) navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RO_YAW_RATE_LIM](#RO_YAW_RATE_LIM) [deg/s]: This is the maximum yaw rate you want to allow for your rover.
|
||||
This will define the stick-to-yaw-rate mapping for all manual modes using closed loop yaw control and set an upper limit for the yaw rate setpoint for all [auto modes](#auto-modes).
|
||||
|
||||
2. [RM_MAX_THR_YAW_R](#RM_MAX_THR_YAW_R) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop yaw rate control.
|
||||
The controller calculates the required speed difference between the left and right motor to achieve the desired yaw rate.
|
||||
This desired speed difference is then linearly mapped to normalized motor commands.
|
||||
To get a good starting value for this parameter drive the rover in manual mode forwards at full throttle and note the ground speed of the vehicle.
|
||||
Then enter _half_ this value for the parameter. <a id="RM_YAW_RATE_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter, first make sure you set [RO_YAW_RATE_P](#RO_YAW_RATE_P) and [RO_YAW_RATE_I](#RO_YAW_RATE_I) to zero.
|
||||
This way the yaw rate is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
Now put the rover in [Acro mode](../flight_modes_rover/mecanum.md#acro-mode) and then move the right-stick of your controller to the right and/or left and hold it at a few different levels for a couple of seconds each.
|
||||
Disarm the rover and from the flight log plot the `adjusted_yaw_rate_setpoint` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) and the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md) over each other.
|
||||
If the actual yaw rate of the rover is higher than the yaw rate setpoint, increase [RM_MAX_THR_YAW_R](#RM_MAX_THR_YAW_R).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_YAW_RATE_P](#RO_YAW_RATE_P) [-]: Proportional gain of the closed loop yaw rate controller.
|
||||
Unlike the feed-forward part of the controller, the closed loop yaw rate control will compare the yaw rate setpoint with the measured yaw rate and adapt to motor commands based on the error between them.
|
||||
The proportional gain is multiplied with this error and that value is added to the motor command.
|
||||
This compensates for disturbances such as uneven ground and external forces.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RM_MAX_THR_YAW_R](#RM_YAW_RATE_P_TUNING).
|
||||
If you tuned [RM_MAX_THR_YAW_R](#RM_MAX_THR_YAW_R) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_YAW_RATE_I](#RO_YAW_RATE_I) [-]: Integral gain of the closed loop yaw controller.
|
||||
The integral gain accumulates the error between the desired and actual yaw rate scaled by the integral gain over time and that value is added to the motor command.
|
||||
|
||||
::: tip
|
||||
An integrator might not be neccessary at this stage, but it will become important for subsequent modes.
|
||||
|
||||
:::
|
||||
|
||||
5. (Optional) [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM) and [RO_YAW_DECEL_LIM](#RO_YAW_DECEL_LIM) [deg/s^2]: This is the maximum yaw acceleration and deceleration you want to allow for your rover.
|
||||
This can be used to smooth the `yaw_rate` setpoints and make their trajectory feasible based on the physical limitation on the rover to improve tracking and avoid integrator build up.
|
||||
|
||||
::: tip
|
||||
Your rover has a maximum possible yaw acceleration/deceleration which is determined by the maximum torque the motor can supply.
|
||||
This may or may not be appropriate for your vehicle and use case.
|
||||
|
||||
One approach to determine an appropriate value is:
|
||||
|
||||
1. Put the rover into [Manual mode](../flight_modes_rover/mecanum.md#manual-mode).
|
||||
2. From a standstill, move the right stick all the way to the right or left until the rover reaches the maximum yaw rate then return the right stick to the middle.
|
||||
3. Disarm the rover and plot the `measured_yaw_rate` from [RoverRateStatus](../msg_docs/RoverRateStatus.md).
|
||||
4. Divide the maximum yaw rate by the time it took to reach it and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
5. Divide the maximum yaw rate by the time it took to return to a standstill and set this as the value for [RO_YAW_ACCEL_LIM](#RO_YAW_ACCEL_LIM).
|
||||
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Acro mode](../flight_modes_rover/mecanum.md#acro-mode).
|
||||
|
||||
## Stabilized Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Acro mode](#acro-mode) must've already been configured!
|
||||
:::
|
||||
|
||||
For [Stabilized mode](../flight_modes_rover/mecanum.md#stabilized-mode) the controller utilizes a closed loop yaw controller, which creates a yaw rate setpoint to control the yaw when it is active:
|
||||
|
||||
|
||||
|
||||
Unlike the closed loop yaw rate, this controller has no feed-forward term.
|
||||
Therefore you only need to tune the closed loop gains:
|
||||
|
||||
1. [RO_YAW_P](#RO_YAW_P) [-]: Proportional gain for the closed loop yaw controller.
|
||||
|
||||
::: tip
|
||||
In stabilized mode the closed loop yaw control is only active when driving a straight line (no yaw rate input).
|
||||
Start with a value of 1 for [RO_YAW_P](#RO_YAW_P).
|
||||
Put the rover into stabilized mode and move the left stick of your controller up and/or down to drive forwards/backwards.
|
||||
Disarm the rover and from the flight log plot the `measured_yaw` and the `adjusted_yaw_setpoint` from the [RoverAttitudeStatus](../msg_docs/RoverAttitudeStatus.md) message over each other.
|
||||
Increase/Decrease the parameter until you are satisfied with the setpoint tracking.
|
||||
|
||||
:::
|
||||
|
||||
:::info
|
||||
For the closed loop yaw control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
Since the yaw and yaw rate controllers are cascaded, there only needs to be one integrator which is in the yaw rate controller.
|
||||
If you observe a steady state error in the yaw setpoint increase the [RO_YAW_RATE_I](#RO_YAW_RATE_I) parameter.
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Stabilized mode](../flight_modes_rover/mecanum.md#stabilized-mode).
|
||||
|
||||
## Position Mode
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Stabilized mode](#stabilized-mode) must already be configured!
|
||||
:::
|
||||
|
||||
[Position mode](../flight_modes_rover/mecanum.md#position-mode) is the most advanced manual mode, utilizing closed loop yaw rate, yaw and speed control and leveraging position estimates.
|
||||
|
||||
To configure set the following parameters:
|
||||
|
||||
:::info
|
||||
The speed control in longitudinal and lateral direction use the same tuning parameters.
|
||||
:::
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM) [m/s]: This is the maximum speed you want to allow for your rover.
|
||||
This will define the stick-to-speed mapping for position mode and set an upper limit for the speed setpoint for all [auto modes](#auto-modes).
|
||||
For mecanum rovers the speed is defined in the direction of travel (magnitude of the velocity vector consisting of the longitudinal and lateral speed).
|
||||
|
||||
2. [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) [m/s]: This parameter is used to calculate the feed-forward term of the closed loop speed control which linearly maps desired speeds to normalized motor commands.
|
||||
A good starting point is the observed ground speed when the rover drives at maximum throttle in [Manual mode](../flight_modes_rover/mecanum.md#manual-mode).
|
||||
|
||||
<a id="RD_SPEED_P_TUNING"></a>
|
||||
|
||||
::: tip
|
||||
To further tune this parameter:
|
||||
|
||||
1. Set [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I) to zero.
|
||||
This way the speed is only controlled by the feed-forward term, which makes it easier to tune.
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and then move the left stick of your controller up and/or down and hold it at a few different levels for a couple of seconds each.
|
||||
3. Disarm the rover and from the flight log plot the `adjusted_speed_body_x_setpoint` and the `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
4. If the actual speed of the rover is higher than the speed setpoint, increase [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED).
|
||||
If it is the other way around decrease the parameter and repeat until you are satisfied with the setpoint tracking.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
::: info
|
||||
If your rover oscillates when driving a straight line in [Position mode](../flight_modes_rover/mecanum.md#position-mode) just set this parameter to the observed ground speed at maximum throttle in [Manual mode](../flight_modes_rover/mecanum.md#manual-mode) and complete steps 5-7 first before continuing the tuning of the closed loop speed control (Steps 2-4).
|
||||
|
||||
:::
|
||||
|
||||
3. [RO_SPEED_P](#RO_SPEED_P) [-]: Proportional gain of the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
This parameter can be tuned the same way as [RO_MAX_THR_SPEED](#RD_SPEED_P_TUNING).
|
||||
If you tuned [RO_MAX_THR_SPEED](#RO_MAX_THR_SPEED) well, you might only need a very small value.
|
||||
|
||||
:::
|
||||
|
||||
4. [RO_SPEED_I](#RO_SPEED_I) [-]: Integral gain for the closed loop speed controller.
|
||||
|
||||
::: tip
|
||||
For the closed loop speed control an integrator gain is useful because this setpoint is often constant for a while and an integrator eliminates steady state errors that can cause the rover to never reach the setpoint.
|
||||
|
||||
:::
|
||||
|
||||
5. [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN): When driving in a straight line (no yaw rate input) position mode leverages the same path following algorithm used in [auto modes](#auto-modes) called [pure pursuit](#pure-pursuit-guidance-logic) to achieve the best possible straight line driving behaviour ([Illustration of control architecture](#pure_pursuit_controller)).
|
||||
This parameter determines how aggressive the controller will steer towards the path.
|
||||
|
||||
::: tip
|
||||
Decreasing the parameter makes it more aggressive but can lead to oscillations.
|
||||
|
||||
To tune this:
|
||||
|
||||
1. Start with a value of 1 for [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN)
|
||||
2. Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and while driving a straight line at approximately half the maximum speed observe its behaviour.
|
||||
3. If the rover does not drive in a straight line, reduce the value of the parameter, if it oscillates around the path increase the value.
|
||||
4. Repeat until you are satisfied with the behaviour.
|
||||
|
||||
|
||||
:::
|
||||
|
||||
6. [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN): Minimum threshold for the lookahead distance used by the [pure pursuit algorithm](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and drive at very low speeds, if the rover starts to oscillate even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then increase the value of [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
:::
|
||||
|
||||
7. [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX): Maximum threshold for the lookahead distance used by [pure pursuit](#pure-pursuit-guidance-logic).
|
||||
|
||||
::: tip
|
||||
Put the rover in [Position mode](../flight_modes_rover/mecanum.md#position-mode) and drive at very high speeds, if the rover does not drive in a straight line even though the tuning of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) was good for medium speeds, then decrease the value of [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX).
|
||||
|
||||
:::
|
||||
|
||||
The rover is now ready to drive in [Position mode](../flight_modes_rover/mecanum.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
:::warning
|
||||
For this mode to work properly [Position mode](#position-mode) must already be configured!
|
||||
:::
|
||||
|
||||
<a id="pure_pursuit_controller"></a>
|
||||
In [auto modes](../flight_modes_rover/mecanum.md#auto-modes) the autopilot takes over navigation tasks using the following control architecture:
|
||||
|
||||
|
||||
|
||||
The mecanum module fully leverages the omnidirectionality of this type of rover by maintaining the initial heading of the rover during the entire mission (see [Pure Pursuit Guidance Logic](#pure-pursuit-guidance-logic)).
|
||||
|
||||
The required parameters are separated into the following sections:
|
||||
|
||||
### Speed
|
||||
|
||||
These parameters are used to calculate the velocity setpoint in auto modes:
|
||||
|
||||
1. [RO_SPEED_LIM](#RO_SPEED_LIM): Sets the default speed ($m/s$) for the rover during the mission (as well as the maximum speed).
|
||||
For mecanum rovers the speed is defined in the direction of travel (magnitude of the velocity vector consisting of the longitudinal and lateral speed).
|
||||
|
||||
2. [RO_DECEL_LIM](#RO_DECEL_LIM) ($m/s^2$) and [RO_JERK_LIM](#RO_JERK_LIM) ($m/s^3$) are used to calculate a velocity trajectory such that the rover comes to a smooth stop as it reaches a waypoint.
|
||||
|
||||
::: tip
|
||||
Plan a mission for the rover to drive a square and observe how it slows down when approaching a waypoint:
|
||||
|
||||
- If the rover decelerates too quickly decrease the [RO_DECEL_LIM](#RO_DECEL_LIM) parameter, if it starts slowing down too early increase the parameter.
|
||||
- If you observe a jerking motion as the rover slows down, decrease the [RO_JERK_LIM](#RO_JERK_LIM) parameter otherwise increase it as much as possible as it can interfere with the tuning of [RO_DECEL_LIM](#RO_DECEL_LIM).
|
||||
|
||||
These two parameters have to be tuned as a pair, repeat until you are satisfied with the behaviour.
|
||||
|
||||
:::
|
||||
|
||||
3. [RM_MISS_SPD_GAIN](#RM_MISS_SPD_GAIN): The rover slows down when approaching a waypoint based on the angle between the line segment from the previous to current waypoint and current to next waypoint.
|
||||
How much the rover slows down can be tuned with this parameter:
|
||||
|
||||
$$
|
||||
v_{transition} = v_{max} \cdot (1 - \theta_{normalized} * k)
|
||||
$$
|
||||
|
||||
with:
|
||||
|
||||
- $v_{transition}:$ Transition speed
|
||||
- $v_{max}:$ Maximum speed ([RO_SPEED_LIM](#RO_SPEED_LIM))
|
||||
- $\theta_{normalized}:$ Angle between the line segment of the prev-current and current-next waypoints, normalized from $[0\degree, 180\degree]$ to $[0, 1]$
|
||||
- $k:$ Tuning parameter ([RM_MISS_SPD_GAIN](#RM_MISS_SPD_GAIN)).
|
||||
|
||||
4. Plot the `adjusted_speed_body_x_setpoint` and `measured_speed_body_x` from the [RoverVelocityStatus](../msg_docs/RoverVelocityStatus.md) message over each other.
|
||||
If the tracking of these setpoints is not satisfactory adjust the values for [RO_SPEED_P](#RO_SPEED_P) and [RO_SPEED_I](#RO_SPEED_I).
|
||||
|
||||
### Path Following
|
||||
|
||||
The [pure pursuit](#pure-pursuit-guidance-logic) algorithm is used to calculate a desired bearing for the vehicle that is then close loop controlled.
|
||||
For mecanum rovers the path following is achieved by directly controlling the velocity of the rover in direction of the desired bearing.
|
||||
During any auto navigation task observe the behaviour of the rover:
|
||||
|
||||
1. If you are unsatisfied with the path following you need to further tune the [pure pursuit](#pure-pursuit-guidance-logic) parameters.
|
||||
2. If the rover does not maintain its initial heading well enough, adjust the value for [RO_YAW_P](#RO_YAW_RATE_P) and potentially further tune [RO_YAW_RATE_I](#RO_YAW_RATE_I).
|
||||
|
||||
## Pure Pursuit Guidance Logic
|
||||
|
||||
The desired bearing setpoints are generated using a pure pursuit algorithm:
|
||||
The controller takes the intersection point between a circle around the vehicle and a line segment.
|
||||
In mission mode this line is usually constructed by connecting the previous and current waypoint:
|
||||
|
||||
|
||||
|
||||
The radius of the circle around the vehicle is used to tune the controller and is often referred to as look-ahead distance.
|
||||
|
||||
The look ahead distance sets how aggressive the controller behaves and is defined as $l_d = v \cdot k$.
|
||||
It depends on the velocity $v$ of the rover and a tuning parameter $k$ that can be set with the parameter [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN).
|
||||
|
||||
:::info
|
||||
A lower value of [PP_LOOKAHD_GAIN](#PP_LOOKAHD_GAIN) makes the controller more aggressive but can lead to oscillations!
|
||||
:::
|
||||
|
||||
The lookahead is constrained between [PP_LOOKAHD_MAX](#PP_LOOKAHD_MAX) and [PP_LOOKAHD_MIN](#PP_LOOKAHD_MIN).
|
||||
|
||||
If the distance from the path to the rover is bigger than the lookahead distance, the rover will target the point on the path that is closest to the rover.
|
||||
|
||||
To summarize, the following parameters can be used to tune the controller:
|
||||
|
||||
| 参数 | 描述 | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | ---- |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius | m |
|
||||
|
||||
## Parameter Overview
|
||||
|
||||
List of all parameters of the mecanum rover module:
|
||||
|
||||
| 参数 | 描述 | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- | ------- |
|
||||
| <a id="RM_WHEEL_TRACK"></a>[RM_WHEEL_TRACK](../advanced_config/parameter_reference.md#RM_WHEEL_TRACK) | Wheel track | m |
|
||||
| <a id="RM_MAX_THR_YAW_R"></a>[RM_MAX_THR_YAW_R](../advanced_config/parameter_reference.md#RM_MAX_THR_YAW_R) | Yaw rate turning left/right wheels at max speed in opposite directions | m/s |
|
||||
| <a id="RM_MISS_SPD_GAIN"></a>[RM_MISS_SPD_GAIN](../advanced_config/parameter_reference.md#RM_MISS_SPD_GAIN) | Tuning parameter for the velocity reduction during waypoint transition | - |
|
||||
| <a id="RM_COURSE_CTL_TH"></a>[RM_COURSE_CTL_TH](../advanced_config/parameter_reference.md#RM_COURSE_CTL_TH) | Threshold to update course control in manual position mode | rad |
|
||||
| <a id="RO_YAW_RATE_LIM"></a>[RO_YAW_RATE_LIM](../advanced_config/parameter_reference.md#RO_YAW_RATE_LIM) | Maximum allowed yaw rate for the rover | deg/s |
|
||||
| <a id="RO_YAW_RATE_P"></a>[RO_YAW_RATE_P](../advanced_config/parameter_reference.md#RO_YAW_RATE_P) | Proportional gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_RATE_I"></a>[RO_YAW_RATE_I](../advanced_config/parameter_reference.md#RO_YAW_RATE_I) | Integral gain for yaw rate controller | - |
|
||||
| <a id="RO_YAW_P"></a>[RO_YAW_P](../advanced_config/parameter_reference.md#RO_YAW_P) | Proportional gain for yaw controller | - |
|
||||
| <a id="RO_SPEED_LIM"></a>[RO_SPEED_LIM](../advanced_config/parameter_reference.md#RO_SPEED_LIM) | Maximum allowed speed for the rover (and default mission speed). | m/s |
|
||||
| <a id="RO_MAX_THR_SPEED"></a>[RO_MAX_THR_SPEED](../advanced_config/parameter_reference.md#RO_MAX_THR_SPEED) | Speed the rover drives at maximum throttle | m/s |
|
||||
| <a id="RO_SPEED_P"></a>[RO_SPEED_P](../advanced_config/parameter_reference.md#RO_SPEED_P) | Proportional gain for speed controller | - |
|
||||
| <a id="RO_SPEED_I"></a>[RO_SPEED_I](../advanced_config/parameter_reference.md#RO_SPEED_I) | Integral gain for speed controller | - |
|
||||
| <a id="PP_LOOKAHD_GAIN"></a>[PP_LOOKAHD_GAIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_GAIN) | Main tuning parameter for pure pursuit | - |
|
||||
| <a id="PP_LOOKAHD_MAX"></a>[PP_LOOKAHD_MAX](../advanced_config/parameter_reference.md#PP_LOOKAHD_MAX) | Maximum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="PP_LOOKAHD_MIN"></a>[PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) | Minimum value for the look ahead radius of the pure pursuit algorithm | m |
|
||||
| <a id="RO_ACCEL_LIM"></a>[RO_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_ACCEL_LIM) | (Optional) Maximum allowed acceleration | m/s^2 |
|
||||
| <a id="RO_DECEL_LIM"></a>[RO_DECEL_LIM](../advanced_config/parameter_reference.md#RO_DECEL_LIM) | (Optional) Maximum allowed deceleration | m/s^2 |
|
||||
| <a id="RO_JERK_LIM"></a>[RO_JERK_LIM](../advanced_config/parameter_reference.md#RO_JERK_LIM) | (Optional) Maximum allowed jerk | $m/s^3$ |
|
||||
| <a id="RO_YAW_ACCEL_LIM"></a>[RO_YAW_ACCEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_ACCEL_LIM) | (Optional) Maximum allowed yaw acceleration | m/s^2 |
|
||||
| <a id="RO_YAW_DECEL_LIM"></a>[RO_YAW_DECEL_LIM](../advanced_config/parameter_reference.md#RO_YAW_DECEL_LIM) | (Optional) Maximum allowed yaw deceleration | m/s^2 |
|
||||
|
||||
## See Also
|
||||
|
||||
- [Drive Modes (Mecanum Rover)](../flight_modes_rover/mecanum.md).
|
||||
@@ -1,161 +0,0 @@
|
||||
# Drive Modes (Ackermann Rover)
|
||||
|
||||
Flight modes (or more accurately "Drive modes" for ground vehicles) provide autopilot support to make it easier to manually drive the vehicle or to execute autonomous missions.
|
||||
|
||||
This section outlines all supported drive modes for [Ackermann rovers](../frames_rover/ackermann.md).
|
||||
|
||||
For information on mapping RC control switches to specific modes see: [Basic Configuration > Flight Modes](../config/flight_mode.md).
|
||||
|
||||
:::warning
|
||||
Selecting any other mode than those listed below will either stop the rover or can lead to undefined behaviour.
|
||||
:::
|
||||
|
||||
## Manual Modes
|
||||
|
||||
Manual modes require stick inputs from the user to drive the vehicle.
|
||||
|
||||
|
||||
|
||||
The sticks provide the same "high level" control effects over direction and rate of movement in all manual modes:
|
||||
|
||||
- `Left stick up/down`: Drive the rover forwards/backwards (controlling speed)
|
||||
- `Right stick left/right`: Make a left/right turn (controlling steering angle ([Manual mode](#manual-mode)) or yaw rate ([Acro](#acro-mode) and [Position](#position-mode))).
|
||||
|
||||
The manual modes provide progressively increasing levels of autopilot support for maintaining a course, speed, and rate of turn, compensating for external factors such as slopes or uneven terrain.
|
||||
|
||||
| Mode | 特性 |
|
||||
| -------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | No autopilot support. User is responsible for keeping the rover on the desired course and maintaining speed and rate of turn. |
|
||||
| [Acro](#acro-mode) | + Maintains the yaw rate (This makes it feel more like driving a car than manual mode). <br>+ Allows maximum yaw rate to be limited (Protects against roll over). |
|
||||
| [Position](#position-mode) | + Maintains the course (Best mode for driving a straight line).<br>+ Maintains speed against disturbances, e.g. when driving up a hill.<br>+ Allows maximum speed to be limited. |
|
||||
|
||||
:::details
|
||||
Overview mode mapping to control effect
|
||||
|
||||
| Mode | Forward/backwards speed | Steering angle/yaw rate | Required measurements |
|
||||
| -------------------------- | ---------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | Directly map stick input to motor command. | Directly map stick input to steering angle. | None. |
|
||||
| [Acro](#acro-mode) | Directly map stick input to motor command. | Stick input creates a yaw rate setpoint for the control system to regulate. | yaw rate. |
|
||||
| [Position](#position-mode) | Stick input creates a speed setpoint for the control system to regulate. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will keep the rover driving in a straight line. | yaw rate, yaw, speed and global position (GPS). |
|
||||
|
||||
:::
|
||||
|
||||
### 手动模式
|
||||
|
||||
In this mode the stick inputs are directly mapped to motor commands.
|
||||
The rover does not attempt to maintain a specific orientation or compensate for external factors like slopes or uneven terrain!
|
||||
The user is responsible for making the necessary adjustments to the stick inputs to keep the rover on the desired course.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Move the steering angle to the left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Manual mode](../config_rover/ackermann.md#manual-mode).
|
||||
|
||||
### Acro Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate measurement.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint (but does not stabilize heading or regulate speed).
|
||||
|
||||
Yaw rate can be directly mapped to a steering input based on the forward speed of the rover:
|
||||
|
||||
<!-- prettier-ignore -->
|
||||
|
||||
$$\delta = \arctan(\frac{w_b \cdot \dot{\psi}}{v})$$
|
||||
|
||||
with
|
||||
|
||||
- $w_b:$ Wheel base,
|
||||
- $\delta:$ Steering angle,
|
||||
- $\dot{\psi}:$ Yaw rate
|
||||
- $v:$ Forward speed.
|
||||
|
||||
For driving this means that the same right hand stick input will cause a different steering angle based on how fast you are driving.
|
||||
By limiting the maximum yaw rate, we can restrict the steering angle based on the speed, which can prevent the rover from rolling over.
|
||||
This mode will feel more like "driving a car" than [Manual mode](#manual-mode).
|
||||
|
||||
:::info
|
||||
The yaw rate is only close loop controlled when driving forwards.
|
||||
When driving backwards the yaw rate setpoint is directly mapped to a steering angle using the equation above.
|
||||
This is due to the fact that rear wheel steering (driving a car with front-wheel steering backwards) is non-minimum-phase w.r.t to the yaw rate which leads to instabilities when doing closed loop control.
|
||||
:::
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will attempt to maintain a zero yaw rate (minimal disturbance rejection) |
|
||||
|
||||
For the configuration/tuning of this mode see [Acro mode](../config_rover/ackermann.md#acro-mode).
|
||||
|
||||
### Stabilized Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate and yaw estimate.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint and will maintain its heading if this setpoint is zero (but does not regulate speed).
|
||||
Compared to [Acro mode](#acro-mode), this mode is much better at driving in a straight line as it can more effectively reject disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the current yaw. |
|
||||
|
||||
For the configuration/tuning of this mode see [Stabilized mode](../config_rover/ackermann.md#stabilized-mode).
|
||||
|
||||
### Position Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate, yaw, speed and global position estimate.
|
||||
:::
|
||||
|
||||
This is the manual mode with the most autopilot support.
|
||||
The vehicle regulates its yaw rate and speed to a setpoint.
|
||||
If the yaw rate setpoint is zero, the controller will remember the GPS coordinates and yaw (heading) of the vehicle and use those to construct a line that the rover will then follow (course control).
|
||||
This offers the highest amount of disturbance rejection, which leads to the best straight line driving behavior.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| Left stick up/down | Stick position sets a forward/back speed setpoint. The vehicle attempts to maintain this speed on slopes etc. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the course of the rover. |
|
||||
|
||||
For the configuration/tuning of this mode see [Position mode](../config_rover/ackermann.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
In auto modes the autopilot takes over control of the vehicle to run missions, return to launch, or perform other autonomous navigation tasks.
|
||||
For the tuning process see the configuration for [Auto modes](../config_rover/ackermann.md#auto-modes).
|
||||
|
||||
### Mission Mode
|
||||
|
||||
_Mission mode_ is an automatic mode that causes the vehicle to execute a predefined autonomous [mission plan](../flying/missions.md) that has been uploaded to the flight controller.
|
||||
The mission is typically created and uploaded with a Ground Control Station (GCS) application, such as [QGroundControl](https://docs.qgroundcontrol.com/master/en/).
|
||||
|
||||
#### Mission commands
|
||||
|
||||
The following commands can be used in missions at time of writing (PX4 v1.16):
|
||||
|
||||
| QGC mission item | 通信 | 描述 |
|
||||
| ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------- |
|
||||
| Mission start | [MAV_CMD_MISSION_START](MAV_CMD_MISSION_START) | Starts the mission. |
|
||||
| Waypoint | [MAV_CMD_NAV_WAYPOINT](MAV_CMD_NAV_WAYPOINT) | Navigate to waypoint. |
|
||||
| Return to launch | [MAV\_CMD\_NAV\_RETURN\_TO\_LAUNCH][MAV_CMD_NAV_RETURN_TO_LAUNCH] | Return to the launch location. |
|
||||
| Change speed | [MAV\_CMD\_DO\_CHANGE\_SPEED][MAV_CMD_DO_CHANGE_SPEED] | Change the speed setpoint |
|
||||
| Set launch location | [MAV_CMD_DO_SET_HOME](MAV_CMD_DO_SET_HOME) | Changes launch location to specified coordinates. |
|
||||
| Jump to item (all) | [MAV\_CMD\_DO\_JUMP][MAV_CMD_DO_JUMP] (and other jump commands) | Jump to specified mission item. |
|
||||
|
||||
[MAV_CMD_MISSION_START]: https://mavlink.io/en/messages/common.html#MAV_CMD_MISSION_START
|
||||
[MAV_CMD_NAV_WAYPOINT]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_WAYPOINT
|
||||
[MAV_CMD_NAV_RETURN_TO_LAUNCH]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_RETURN_TO_LAUNCH
|
||||
[MAV_CMD_DO_CHANGE_SPEED]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_CHANGE_SPEED
|
||||
[MAV_CMD_DO_SET_HOME]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_SET_HOME
|
||||
[MAV_CMD_DO_JUMP]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_JUMP
|
||||
|
||||
### Return Mode
|
||||
|
||||
This mode uses the [pure pursuit guidance logic](../config_rover/ackermann.md#pure-pursuit-guidance-logic) with the launch position as goal.
|
||||
Return mode can be activated through the respective [mission command](#mission-commands) or through the ground station UI.
|
||||
@@ -1,143 +0,0 @@
|
||||
# Drive Modes (Differential Rover)
|
||||
|
||||
Flight modes (or more accurately "Drive modes" for ground vehicles) provide autopilot support to make it easier to manually drive the vehicle or to execute autonomous missions.
|
||||
|
||||
This section outlines all supported drive modes for differential rovers.
|
||||
|
||||
For information on mapping RC control switches to specific modes see: [Basic Configuration > Flight Modes](../config/flight_mode.md).
|
||||
|
||||
:::warning
|
||||
Selecting any other mode than those listed below will either stop the rover or can lead to undefined behaviour.
|
||||
:::
|
||||
|
||||
## Manual Modes
|
||||
|
||||
Manual modes require stick inputs from the user to drive the vehicle.
|
||||
|
||||
|
||||
|
||||
The sticks provide the same "high level" control effects over direction and rate of movement in all manual modes:
|
||||
|
||||
- `Left stick up/down`: Drive the rover forwards/backwards (controlling speed)
|
||||
- `Right stick left/right`: Rotate the rover to the left/right (controlling yaw rate).
|
||||
|
||||
The manual modes provide progressively increasing levels of autopilot support for maintaining a course, speed, and rate of turn, compensating for external factors such as slopes or uneven terrain.
|
||||
|
||||
| Mode | 特性 |
|
||||
| ------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | No autopilot support. User is responsible for keeping the rover on the desired course and maintaining speed and rate of turn. |
|
||||
| [Acro](#acro-mode) | + Maintains the yaw rate (This makes it slightly better at holding a straight line in uneven terrain). <br>+ Allows maximum yaw rate to be limited. |
|
||||
| [Stabilized](#stabilized-mode) | + Maintans the yaw (This makes it significantly better at holding a straight line). |
|
||||
| [Position](#position-mode) | + Maintains the course (Best mode for driving a straight line).<br>+ Maintains speed against disturbances, e.g. when driving up a hill.<br>+ Allows maximum speed to be limited. |
|
||||
|
||||
:::details
|
||||
Overview mode mapping to control effect
|
||||
|
||||
| Mode | Forwards/backwards speed | Yaw rate | Required measurements |
|
||||
| ------------------------------ | ---------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | Directly map stick input to motor commands. | Directly map stick input to motor commands. | None. |
|
||||
| [Acro](#acro-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. | Yaw rate. |
|
||||
| [Stabilized](#stabilized-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will maintain the current yaw (heading) of the rover. | Yaw rate and yaw. |
|
||||
| [Position](#position-mode) | Stick input creates a speed setpoint for the control system to regulate. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will keep the rover driving in a straight line. | Yaw rate, yaw, speed and global position (GPS). |
|
||||
|
||||
:::
|
||||
|
||||
### 手动模式
|
||||
|
||||
In this mode the stick inputs are directly mapped to motor commands. The rover does not attempt to maintain a specific orientation or compensate for external factors like slopes or uneven terrain!
|
||||
The user is responsible for making the necessary adjustments to the stick inputs to keep the rover on the desired course.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | --------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Yaw the rover to the left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Manual mode](../config_rover/differential.md#manual-mode).
|
||||
|
||||
### Acro Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate measurement.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint (but does not stabilize heading or regulate speed).
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will attempt to maintain a zero yaw rate (minimal disturbance rejection) |
|
||||
|
||||
For the configuration/tuning of this mode see [Acro mode](../config_rover/differential.md#acro-mode).
|
||||
|
||||
### Stabilized Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate and yaw estimate.
|
||||
:::
|
||||
|
||||
In this mode the vehicle regulates its yaw rate to a setpoint and will maintain its heading if this setpoint is zero (but does not regulate speed).
|
||||
Compared to [Acro mode](#acro-mode), this mode is much better at driving in a straight line as it can more effectively reject disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the current yaw. |
|
||||
|
||||
For the configuration/tuning of this mode see [Stabilized mode](../config_rover/differential.md#stabilized-mode).
|
||||
|
||||
### Position Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate, yaw, speed and global position estimate.
|
||||
:::
|
||||
|
||||
This is the manual mode with the most autopilot support.
|
||||
The vehicle regulates its yaw rate and speed to a setpoint.
|
||||
If the yaw rate setpoint is zero, the controller will remember the GNSS coordinates and yaw (heading) of the vehicle and use those to construct a line that the rover will then follow (course control).
|
||||
This offers the highest amount of disturbance rejection, which leads to the best straight line driving behavior.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| Left stick up/down | Create a speed setpoint for the control system to regulate. |
|
||||
| Right stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the course of the rover. |
|
||||
|
||||
For the configuration/tuning of this mode see [Position mode](../config_rover/differential.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
In auto modes the autopilot takes over control of the vehicle to run missions, return to launch, or perform other autonomous navigation tasks.
|
||||
For the configuration/tuning of these modes see [Auto Modes](../config_rover/differential.md#auto-modes).
|
||||
|
||||
### Mission Mode
|
||||
|
||||
_Mission mode_ is an automatic mode in which the vehicle executes a predefined autonomous [mission plan](../flying/missions.md) that has been uploaded to the flight controller.
|
||||
The mission is typically created and uploaded with a Ground Control Station (GCS) application, such as [QGroundControl](https://docs.qgroundcontrol.com/master/en/).
|
||||
|
||||
#### Mission commands
|
||||
|
||||
The following commands can be used in missions at time of writing (PX4 v1.16):
|
||||
|
||||
| QGC mission item | 通信 | 描述 |
|
||||
| ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------ |
|
||||
| Mission start | [MAV_CMD_MISSION_START](MAV_CMD_MISSION_START) | Starts the mission. |
|
||||
| Waypoint | [MAV_CMD_NAV_WAYPOINT](MAV_CMD_NAV_WAYPOINT) | Navigate to waypoint. |
|
||||
| Return to launch | [MAV\_CMD\_NAV\_RETURN\_TO\_LAUNCH][MAV_CMD_NAV_RETURN_TO_LAUNCH] | Return to the launch location. |
|
||||
| Delay until | [MAV_CMD_NAV_DELAY](MAV_CMD_NAV_DELAY) | The rover will stop for a specified amount of time. |
|
||||
| Change speed | [MAV\_CMD\_DO\_CHANGE\_SPEED][MAV_CMD_DO_CHANGE_SPEED] | Change the speed setpoint |
|
||||
| Set launch location | [MAV_CMD_DO_SET_HOME](MAV_CMD_DO_SET_HOME) | Changes launch location to specified coordinates. |
|
||||
| Jump to item (all) | [MAV\_CMD\_DO\_JUMP][MAV_CMD_DO_JUMP] (and other jump commands) | Jump to specified mission item. |
|
||||
| Loiter (all) | [MAV\_CMD\_NAV\_LOITER\_TIME][MAV_CMD_NAV_LOITER_TIME] (and other loiter commands) | Stop the rover for given time. Other commands stop indefinitely. |
|
||||
|
||||
[MAV_CMD_MISSION_START]: https://mavlink.io/en/messages/common.html#MAV_CMD_MISSION_START
|
||||
[MAV_CMD_NAV_WAYPOINT]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_WAYPOINT
|
||||
[MAV_CMD_NAV_RETURN_TO_LAUNCH]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_RETURN_TO_LAUNCH
|
||||
[MAV_CMD_NAV_DELAY]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_DELAY
|
||||
[MAV_CMD_DO_CHANGE_SPEED]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_CHANGE_SPEED
|
||||
[MAV_CMD_DO_SET_HOME]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_SET_HOME
|
||||
[MAV_CMD_NAV_LOITER_TIME]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_LOITER_TIME
|
||||
[MAV_CMD_DO_JUMP]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_JUMP
|
||||
|
||||
### Return Mode
|
||||
|
||||
This mode uses the [pure pursuit guidance logic](../config_rover/differential.md#pure-pursuit-guidance-logic) with the launch position as goal.
|
||||
Return mode can be activated through the respective [mission command](#mission-commands) or through the ground station UI.
|
||||
@@ -1,168 +0,0 @@
|
||||
# Drive Modes (Mecanum Rover)
|
||||
|
||||
Flight modes (or more accurately "Drive modes" for ground vehicles) provide autopilot support to make it easier to manually drive the vehicle or to execute autonomous missions.
|
||||
|
||||
This section outlines all supported drive modes for mecanum rovers.
|
||||
|
||||
For information on mapping RC control switches to specific modes see: [Basic Configuration > Flight Modes](../config/flight_mode.md).
|
||||
|
||||
:::warning
|
||||
Selecting any other mode than those listed below will either stop the rover or can lead to undefined behaviour.
|
||||
:::
|
||||
|
||||
## Manual Modes
|
||||
|
||||
Manual modes require stick inputs from the user to drive the vehicle.
|
||||
|
||||
|
||||
|
||||
The sticks provide the same "high level" control effects over direction and rate of movement in all manual modes:
|
||||
|
||||
- `Left stick up/down`: Drive the rover forwards/backwards (controlling speed)
|
||||
- `Left stick left/right`: Yaw the rover to the left/right (controlling yaw rate).
|
||||
- `Right stick left/right`: Drive the rover left/right (controlling speed).
|
||||
|
||||
The manual modes provide progressively increasing levels of autopilot support for maintaining a course, speed, and rate of turn, compensating for external factors such as slopes or uneven terrain.
|
||||
|
||||
| Mode | 特性 |
|
||||
| ------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| [Manual](#manual-mode) | No autopilot support. User is responsible for keeping the rover on the desired course and maintaining speed and rate of turn. |
|
||||
| [Acro](#acro-mode) | + Maintains yaw rate (This makes it slightly better at holding a straight line in uneven terrain). <br>+ Allows maximum yaw rate to be limited. |
|
||||
| [Stabilized](#stabilized-mode) | + Maintains yaw (This makes it significantly better at holding a straight line) . |
|
||||
| [Position](#position-mode) | + Best mode for holding a straight line.<br>+ Maintains speed against disturbances, e.g. when driving up a hill<br>+ Allows maximum speed to be limited. |
|
||||
|
||||
:::details
|
||||
Overview mode mapping to control effect
|
||||
|
||||
| Mode | Longitudinal/Lateral speed | Yaw rate | Required measurements |
|
||||
| ------------------------------ | ------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------- |
|
||||
| [Manual](#manual-mode) | Directly map stick input to motor commands. | Directly map stick input to motor commands. | None. |
|
||||
| [Acro](#acro-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. | Yaw rate. |
|
||||
| [Stabilized](#stabilized-mode) | Directly map stick input to motor commands. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will maintain the current yaw (heading) of the rover. | Yaw rate and yaw. |
|
||||
| [Position](#position-mode) | Stick input creates a velocity setpoint for the control system to regulate. | Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will keep the rover driving in a straight line. | Yaw rate, yaw, velocity and global position (GPS). |
|
||||
|
||||
:::
|
||||
|
||||
### 手动模式
|
||||
|
||||
In this mode the stick inputs are directly mapped to motor commands.
|
||||
The rover does not attempt to maintain a specific orientation or compensate for external factors like slopes or uneven terrain!
|
||||
The user is responsible for making the necessary adjustments to the stick inputs to keep the rover on the desired course.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | --------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Left stick left/right | Yaw the rover to the left/right. |
|
||||
| Right stick left/right | Drive the rover left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Manual mode](../config_rover/mecanum.md#manual-mode).
|
||||
|
||||
### Acro Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate measurement.
|
||||
:::
|
||||
|
||||
The vehicle regulates its yaw rate (Left stick left/right) to a setpoint, and a maximum yaw rate can also be specified.
|
||||
Heading and speed are not controlled.
|
||||
|
||||
Compared to [Manual mode](#manual-mode) this introduces the following new features:
|
||||
|
||||
- The yaw rate control ensures that the rover turns at the requested rate even on different surfaces and due to other external forces (such as wind).
|
||||
- Slightly better at driving in a straight line because if the input is zero PX4 will attempt to maintain a zero yaw rate.
|
||||
This is resistant to minor disturbances.
|
||||
- Upper limit for the yaw rate can be used to tune how aggressive the rover turns.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Left stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will attempt to maintain a zero yaw rate (minimal disturbance rejection) |
|
||||
| Right stick left/right | Drive the rover left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Acro mode](../config_rover/mecanum.md#acro-mode).
|
||||
|
||||
### Stabilized Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate and yaw estimate.
|
||||
:::
|
||||
|
||||
The vehicle regulates its yaw rate to a setpoint, and a maximum yaw rate can also be specified.
|
||||
The vehicle regulates its yaw to a setpoint when the yaw rate setpoint is zero, maintaining the heading.
|
||||
Speed is not controlled.
|
||||
|
||||
Compared to [Acro mode](#acro-mode), this mode is much better at driving in a straight line as it can more effectively reject disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||||
| Left stick up/down | Drive the rover forwards/backwards. |
|
||||
| Left stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the current yaw. |
|
||||
| Right stick left/right | Drive the rover left/right. |
|
||||
|
||||
For the configuration/tuning of this mode see [Stabilized mode](../config_rover/mecanum.md#stabilized-mode).
|
||||
|
||||
### Position Mode
|
||||
|
||||
:::info
|
||||
This mode requires a yaw rate, yaw, speed and global position estimate.
|
||||
:::
|
||||
|
||||
This is the mode with the most autopilot support.
|
||||
|
||||
The vehicle regulates its yaw rate to a setpoint, and a maximum yaw rate can also be specified.
|
||||
The path is maintained when the yaw rate setpoint is zero using global position (the controller constructs a line in the direction of the velocity input (forward + lateral speed) that the rover will then follow by tracking the global position).
|
||||
Speed is regulated to a setpoint, and a maximum value can be set.
|
||||
|
||||
Compared to [Stabilized Mode](#stabilized-mode) this introduces the following features:
|
||||
|
||||
- Upper limit for the speed (see [Position Mode](../config_rover/mecanum.md#position-mode)) to tune how fast the rover is allowed to drive.
|
||||
- The speed control ensures that the rover drives the requested speed even under disturbances (i.e. driving up a hill, against wind, with a heavier payload etc.).
|
||||
- The course control leads to the best straight line driving behaviour, as the vehicle will follow the intended path of the vehicle and return to it if forced off-track
|
||||
This is much better than stabilized mode, which can be forced off the intended track by disturbances.
|
||||
|
||||
| Stick | Effect |
|
||||
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||||
| Left stick up/down | Create a forward speed setpoint for the control system to regulate. |
|
||||
| Left stick left/right | Create a yaw rate setpoint for the control system to regulate. If this input is zero the control system will maintain the course of the rover. |
|
||||
| Right stick left/right | Create a lateral speed setpoint for the control system to regulate. |
|
||||
|
||||
For the configuration/tuning of this mode see [Position mode](../config_rover/mecanum.md#position-mode).
|
||||
|
||||
## Auto Modes
|
||||
|
||||
In auto modes the autopilot takes over control of the vehicle to run missions, return to launch, or perform other autonomous navigation tasks.
|
||||
For the configuration/tuning of these modes see [Auto Modes](../config_rover/mecanum.md#auto-modes).
|
||||
|
||||
### Mission Mode
|
||||
|
||||
_Mission mode_ is an automatic mode in which the vehicle executes a predefined autonomous [mission plan](../flying/missions.md) that has been uploaded to the flight controller.
|
||||
The mission is typically created and uploaded with a Ground Control Station (GCS) application, such as [QGroundControl](https://docs.qgroundcontrol.com/master/en/).
|
||||
|
||||
#### Mission commands
|
||||
|
||||
The following commands can be used in missions at time of writing (PX4 v1.16):
|
||||
|
||||
| QGC mission item | 通信 | 描述 |
|
||||
| ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------ |
|
||||
| Mission start | [MAV_CMD_MISSION_START](MAV_CMD_MISSION_START) | Starts the mission. |
|
||||
| Waypoint | [MAV_CMD_NAV_WAYPOINT](MAV_CMD_NAV_WAYPOINT) | Navigate to waypoint. |
|
||||
| Return to launch | [MAV\_CMD\_NAV\_RETURN\_TO\_LAUNCH][MAV_CMD_NAV_RETURN_TO_LAUNCH] | Return to the launch location. |
|
||||
| Delay until | [MAV_CMD_NAV_DELAY](MAV_CMD_NAV_DELAY) | The rover will stop for a specified amount of time. |
|
||||
| Change speed | [MAV\_CMD\_DO\_CHANGE\_SPEED][MAV_CMD_DO_CHANGE_SPEED] | Change the speed setpoint |
|
||||
| Set launch location | [MAV_CMD_DO_SET_HOME](MAV_CMD_DO_SET_HOME) | Changes launch location to specified coordinates. |
|
||||
| Jump to item (all) | [MAV\_CMD\_DO\_JUMP][MAV_CMD_DO_JUMP] (and other jump commands) | Jump to specified mission item. |
|
||||
| Loiter (all) | [MAV\_CMD\_NAV\_LOITER\_TIME][MAV_CMD_NAV_LOITER_TIME] (and other loiter commands) | Stop the rover for given time. Other commands stop indefinitely. |
|
||||
|
||||
[MAV_CMD_MISSION_START]: https://mavlink.io/en/messages/common.html#MAV_CMD_MISSION_START
|
||||
[MAV_CMD_NAV_WAYPOINT]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_WAYPOINT
|
||||
[MAV_CMD_NAV_RETURN_TO_LAUNCH]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_RETURN_TO_LAUNCH
|
||||
[MAV_CMD_NAV_DELAY]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_DELAY
|
||||
[MAV_CMD_DO_CHANGE_SPEED]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_CHANGE_SPEED
|
||||
[MAV_CMD_DO_SET_HOME]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_SET_HOME
|
||||
[MAV_CMD_NAV_LOITER_TIME]: https://mavlink.io/en/messages/common.html#MAV_CMD_NAV_LOITER_TIME
|
||||
[MAV_CMD_DO_JUMP]: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_JUMP
|
||||
|
||||
### Return Mode
|
||||
|
||||
This mode uses the [pure pursuit guidance logic](../config_rover/mecanum.md#pure-pursuit-guidance-logic) with the launch position as goal.
|
||||
Return mode can be activated through the respective [mission command](#mission-commands) or through the ground station UI.
|
||||
@@ -1,14 +0,0 @@
|
||||
# Ackermann Rovers
|
||||
|
||||
<Badge type="tip" text="PX4 v1.16" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
An _Ackermann rover_ controls its direction by pointing the front wheels in the direction of travel — the [Ackermann steering geometry](https://en.wikipedia.org/wiki/Ackermann_steering_geometry) compensates for the fact that wheels on the inside and outside of the turn move at different rates.
|
||||
This kind of steering is used on most commercial vehicles, including cars, trucks etc.
|
||||
|
||||
:::info
|
||||
PX4 does not require that the vehicle uses the Ackermann geometry and will work with any front-steering rover.
|
||||
:::
|
||||
|
||||
|
||||
|
||||
See [Configuration/Tuning](../config_rover/ackermann.md) to set up your rover and [Drive Modes](../flight_modes_rover/ackermann.md) for the supported flight (aka drive) modes.
|
||||
@@ -1,170 +0,0 @@
|
||||
# Ackermann Rover
|
||||
|
||||
<Badge type="tip" text="main (PX4 v1.16+)" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
An _Ackermann rover_ controls its direction by pointing the front wheels in the direction of travel — the [Ackermann steering geometry](https://en.wikipedia.org/wiki/Ackermann_steering_geometry) compensates for the fact that wheels on the inside and outside of the turn move at different rates.
|
||||
This kind of steering is used on most commercial vehicles, including cars, trucks etc.
|
||||
|
||||
|
||||
|
||||
:::info
|
||||
PX4 does not require that the vehicle uses the Ackermann geometry and will work with any front-steering rover.
|
||||
:::
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To start using the ackermann rover:
|
||||
|
||||
1. Enable the module by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select the _Generic Rover Ackermann_:
|
||||
|
||||
|
||||
|
||||
::: warning
|
||||
Do not use the _Generic Ground Vehicle (Ackermann)_ airframe as that will load the [(Deprecated) Rover Position Control](../frames_rover/rover_position_control.md) module.
|
||||
|
||||
:::
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe is not displayed and you have checked that you are using rover firmware (not the default), you can alternatively enable this frame by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `51000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Open the [Actuators Configuration & Testing](../config/actuators.md) to map the steering and throttle functions to flight controller outputs.
|
||||
|
||||
This is sufficient to drive the the rover in [manual mode](../flight_modes_rover/index.md#manual-mode) (see [Drive modes](../flight_modes_rover/index.md)).
|
||||
|
||||
:::info
|
||||
Many features of this module are disabled by default, and are only enabled by setting certain parameters.
|
||||
The [Tuning (basic)](#tuning-basic) section goes through the minimum setup required to start driving missions
|
||||
and the [Tuning (advanced)](#tuning-advanced) section outlines the remaining features and tuning variables of the module.
|
||||
:::
|
||||
|
||||
## Tuning (Basic)
|
||||
|
||||
To start driving missions navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------- | ---- |
|
||||
| <a id="RA_WHEEL_BASE"></a>[RA_WHEEL_BASE](../advanced_config/parameter_reference.md#RA_WHEEL_BASE) | Wheel-base of the rover which is measured from the back to the front wheel | m |
|
||||
| <a id="RA_MAX_STR_ANG"></a>[RA_MAX_STR_ANG](../advanced_config/parameter_reference.md#RA_MAX_STR_ANG) | Maximum steering angle of the rover | deg |
|
||||
| <a id="RA_MISS_VEL_DEF"></a>[RA_MISS_VEL_DEF](../advanced_config/parameter_reference.md#RA_MISS_VEL_DEF) | Default velocity the rover will drive during the mission | m/s |
|
||||
|
||||
|
||||
|
||||
This is enough to start driving missions, but depending on the rover might not yet lead to satisfactory performance .
|
||||
If that is the case further tuning is required which is outlined in [Mission parameters](#mission-parameters).
|
||||
|
||||
## Tuning (Advanced)
|
||||
|
||||
To get an overview of all parameters that are related to the Ackermann rover module navigate to the _Rover Ackermann_ group in the _Parameters_ section of QGroundControl.
|
||||
|
||||
### General Parameters
|
||||
|
||||
These parameters affect the general behaviour of the rover. This will influence both auto and manual modes.
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------ | ---- |
|
||||
| <a id="RA_MAX_SPEED"></a>[RA_MAX_SPEED](../advanced_config/parameter_reference.md#RA_MAX_SPEED) | Speed the rover drives at maximum throttle | m/s |
|
||||
|
||||
This is used for a feed-forward term on the speed controller in mission mode and necessary for the [acceleration slew rate](#slew-rates).
|
||||
|
||||
#### Slew Rates
|
||||
|
||||
Slew rates limit how fast the signal that is sent to the motors is allowed to change:
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------- | ----- |
|
||||
| <a id="RA_MAX_ACCEL"></a>[RA_MAX_ACCEL](../advanced_config/parameter_reference.md#RA_MAX_ACCEL) | Limit on the acceleration of the rover | m/s^2 |
|
||||
| <a id="RA_MAX_STR_RATE"></a>[RA_MAX_STR_RATE](../advanced_config/parameter_reference.md#RA_MAX_STR_RATE) | Limit on the steering rate | deg/s |
|
||||
|
||||
:::warning
|
||||
The slew rates are not based on measurements but on assumed linear relation between the throttle input and [RA_MAX_SPEED](#RA_MAX_SPEED) or steering input and [RA_MAX_STR_ANG](#RA_MAX_STR_ANG) respectively.
|
||||
Therefore these two parameters have to be set for the slew rates to work!
|
||||
:::
|
||||
|
||||
## Mission Parameters
|
||||
|
||||
These parameters only affect vehicle in [Mission Mode](../flight_modes_rover/index.md#mission-mode).
|
||||
|
||||
:::warning
|
||||
The parameters in [Tuning (basic)](#tuning-basic) must also be set to drive missions!
|
||||
:::
|
||||
|
||||
The module uses a control algorithm called pure pursuit, see [Pure Pursuit Guidance Logic](../flight_modes_rover/index.md#pure-pursuit-guidance-logic) for the basic tuning process.
|
||||
|
||||
:::info
|
||||
Increasing [PP_LOOKAHD_MIN](../advanced_config/parameter_reference.md#PP_LOOKAHD_MIN) can help to make the steering less aggressive at slow speeds.
|
||||
This can be useful especially if the [corner slow down effect](#corner-slow-down) is enabled.
|
||||
:::
|
||||
|
||||
### Cornering Parameters
|
||||
|
||||
#### Corner cutting
|
||||
|
||||
The module employs a special cornering logic causing the rover to "cut corners" to achieve a smooth trajectory.
|
||||
This is done by scaling the acceptance radius based on the corner the rover has to drive (for geometric explanation see [Cornering logic](#mission-cornering-logic-info-only)).
|
||||
|
||||
|
||||
|
||||
The degree to which corner cutting is allowed can be tuned, or disabled, with the following parameters:
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------- | ---- |
|
||||
| <a id="NAV_ACC_RAD"></a>[NAV_ACC_RAD](../advanced_config/parameter_reference.md#NAV_ACC_RAD) | Default acceptance radius | m |
|
||||
| <a id="RA_ACC_RAD_MAX"></a>[RA_ACC_RAD_MAX](../advanced_config/parameter_reference.md#RA_ACC_RAD_MAX) | Maximum radius the acceptance radius can be scaled to | m |
|
||||
| <a id="RA_ACC_RAD_GAIN"></a>[RA_ACC_RAD_GAIN](../advanced_config/parameter_reference.md#RA_ACC_RAD_GAIN) | Tuning parameter | - |
|
||||
|
||||
The tuning parameter is a multiplicand on the calculated ideal acceptance radius to account for dynamic effects.
|
||||
|
||||
#### Corner slow down
|
||||
|
||||
To smoothen the trajectory further and reduce the risk of the rover rolling over, the mission speed is reduced as the rover gets closer to a waypoint:
|
||||
|
||||
- During cornering the rover drives at a speed that is equal to the the inverse of the acceptance radius (calculated using the [corner cutting logic](#corner-cutting)) multiplied with a tuning parameter called [RA_MISS_VEL_GAIN](#RA_MISS_VEL_GAIN).
|
||||
- In between waypoints (straight line) the rover speed is regulated such that it will arrive at the acceptance radius of the waypoint with the desired cornering speed.
|
||||
This requires [RA_MAX_ACCEL](#RA_MAX_ACCEL) and [RA_MAX_JERK](#RA_MAX_JERK) to be set.
|
||||
|
||||
The mission speed is constrained between a minimum allowed speed [RA_MISS_VEL_MIN](#RA_MISS_VEL_MIN) and the default mission speed [RA_MISS_VEL_DEF](#RA_MISS_VEL_DEF).
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------- | ------- |
|
||||
| <a id="RA_MISS_VEL_DEF"></a>[RA_MISS_VEL_DEF](../advanced_config/parameter_reference.md#RA_MISS_VEL_DEF) | Default mission speed | $m/s$ |
|
||||
| <a id="RA_MISS_VEL_MIN"></a>[RA_MISS_VEL_MIN](../advanced_config/parameter_reference.md#RA_MISS_VEL_MIN) | Minimum the speed can be reduced to during cornering | $m/s$ |
|
||||
| <a id="RA_MISS_VEL_GAIN"></a>[RA_MISS_VEL_GAIN](../advanced_config/parameter_reference.md#RA_MISS_VEL_GAIN) | Tuning parameter for the velocity reduction | - |
|
||||
| <a id="RA_MAX_JERK"></a>[RA_MAX_JERK](../advanced_config/parameter_reference.md#RA_MAX_JERK) | Limit for forwards acc/deceleration change. | $m/s^3$ |
|
||||
|
||||
### Mission Cornering Logic (Info only)
|
||||
|
||||
To enable a smooth trajectory, the acceptance radius of waypoints is scaled based on the angle between a line segment from the current-to-previous and current-to-next waypoints.
|
||||
The ideal trajectory would be to arrive at the next line segment with the heading pointing towards the next waypoint.
|
||||
For this purpose the minimum turning circle of the rover is inscribed tangentially to both line segments.
|
||||
|
||||
|
||||
|
||||
The acceptance radius of the waypoint is set to the distance from the waypoint to the tangential points between the circle and the line segments:
|
||||
|
||||
$$
|
||||
\begin{align*}
|
||||
r_{min} &= \frac{L}{\sin\left( \delta_{max}\right) } \\
|
||||
\theta &= \frac{1}{2}\arccos\left( \frac{\vec{a}*\vec{b}}{|\vec{a}||\vec{b}|}\right) \\
|
||||
r_{acc} &= \frac{r_{min}}{\tan\left( \theta\right) }
|
||||
\end{align*}
|
||||
$$
|
||||
|
||||
| Symbol | Description | Unit |
|
||||
| ----------------------------------- | ---------------------------------- | ---- |
|
||||
| $\vec{a}$ | Vector from current to previous WP | m |
|
||||
| $\vec{b}$ | Vector from current to next WP | m |
|
||||
| $r_{min}$ | Minimum turn radius | m |
|
||||
| $\delta_{max}$ | Maximum steer angle | m |
|
||||
| $r_{acc}$ | Acceptance radius | m |
|
||||
|
||||
<!--
|
||||
## Parameters
|
||||
|
||||
The following parameters affect the ackermann-steering rover:
|
||||
-->
|
||||
@@ -1,86 +0,0 @@
|
||||
# Aion Robotics R1 UGV
|
||||
|
||||
<Badge type="tip" text="PX4 v1.15" />
|
||||
|
||||
The [Aion R1](https://www.aionrobotics.com/) vehicle was chosen to test and improve the differential drive support for PX4, and to improve driver support for Roboclaw Motor Controllers, such as the [RoboClaw 2x15A](https://www.basicmicro.com/RoboClaw-2x15A-Motor-Controller_p_10.html).
|
||||
|
||||
The documentation and driver information here should also make it easier to work with Roboclaw controllers on other vehicles, and to work with vehicles like the [Aion R6](https://www.aionrobotics.com/r6).
|
||||
|
||||
Currently, PX4 supports MANUAL mode for this setup.
|
||||
|
||||
|
||||
|
||||
## 配件列表
|
||||
|
||||
- [Aion R1 (Discontinued)](https://www.aionrobotics.com/)
|
||||
- [Documentation](https://github-docs.readthedocs.io/en/latest/r1-ugv.html)
|
||||
- [RoboClaw 2x15A](https://www.basicmicro.com/RoboClaw-2x15A-Motor-Controller_p_10.html)
|
||||
- [R1 Roboclaw specifications](https://resources.basicmicro.com/aion-robotics-r1-autonomous-robot/)
|
||||
- [Auterion Skynode](../companion_computer/auterion_skynode.md)
|
||||
|
||||
## 组装
|
||||
|
||||
The assembly consists of a 3D-printed frame on which all the autopilot parts were attached.
|
||||
For this build this includes an [Auterion Skynode](../companion_computer/auterion_skynode.md), connected to a Pixhawk Adapter Board that interfaces with the RoboClaw motor controllers over serial.
|
||||
|
||||
|
||||
|
||||
:::info
|
||||
If using a standard Pixhawk you could connect the RoboClaw to the Autopilot without an Adapter Board.
|
||||
:::
|
||||
|
||||
The RoboClaw should be connected to a suitable suitable serial (UART) port on the flight controller, such as `GPS2` or `TELEM1`.
|
||||
Other RoboClaw wiring is detailed in the [RoboClaw User Manual](https://downloads.basicmicro.com/docs/roboclaw_user_manual.pdf) 'Packet Serial Wiring' section and shown below (this setup has been validated for compatibility).
|
||||
|
||||
|
||||
|
||||
## PX4 配置
|
||||
|
||||
### Rover Configuration
|
||||
|
||||
Use _QGroundControl_ for rover configuration:
|
||||
|
||||
1. In the [Basic Configuration](../config/index.md) section, select the [Airframe](../config/airframe.md) tab.
|
||||
2. Choose **Aion Robotics R1 UGV** under the **Rover** category.
|
||||
|
||||
|
||||
|
||||
### RoboClaw Configuration
|
||||
|
||||
First configure the serial connection:
|
||||
|
||||
1. Navigate to the [Parameters](../advanced_config/parameters.md) section in QGroundControl.
|
||||
|
||||
- Set the [RBCLW_SER_CFG](../advanced_config/parameter_reference.md#RBCLW_SER_CFG) parameter to the serial port to which the RoboClaw is connected (such as `GPS2`).
|
||||
- [RBCLW_COUNTS_REV](../advanced_config/parameter_reference.md#RBCLW_COUNTS_REV) specifies the number of encoder counts required for one wheel revolution.
|
||||
This value should be left at `1200` for the tested `RoboClaw 2x15A Motor Controller`.
|
||||
Adjust the value based on your specific encoder and wheel setup.
|
||||
- RoboClaw motor controllers must be assigned a unique address on the bus.
|
||||
The default address is 128 and you should not need to change this (if you do, update the PX4 parameter [RBCLW_ADDRESS](../advanced_config/parameter_reference.md#RBCLW_ADDRESS) to match).
|
||||
|
||||
::: info
|
||||
PX4 does not support multiple RoboClaw motor controllers in the same vehicle — each controller needs a unique address on the bus, and there is only one parameter for setting the address in PX4 (`RBCLW_ADDRESS`).
|
||||
|
||||
:::
|
||||
|
||||
Then configure the actuator configuration:
|
||||
|
||||
1. Navigate to [Actuators Configuration & Testing](../config/actuators.md) in QGroundControl.
|
||||
2. Select the RoboClaw driver from the list of _Actuator Outputs_.
|
||||
|
||||
For the channel assignments, disarm, minimum, and maximum values, please refer to the image below.
|
||||
|
||||
|
||||
|
||||
For systems with more than two motors, it is possible to assign the same function to several motors.
|
||||
The reason for the unusual values, can be found in the [RoboClaw User Manual](https://downloads.basicmicro.com/docs/roboclaw_user_manual.pdf) under `Compatibility Commands` for `Packet Serial`:
|
||||
|
||||
```plain
|
||||
Drive motor forward. Valid data range is 0 - 127. A value of 127 = full speed forward, 64 =
|
||||
about half speed forward and 0 = full stop.
|
||||
```
|
||||
|
||||
## See also
|
||||
|
||||
- [roboclaw](../modules/modules_driver.md#roboclaw) driver
|
||||
- [Roboclaw User Manual](https://downloads.basicmicro.com/docs/roboclaw_user_manual.pdf)
|
||||
@@ -1,11 +0,0 @@
|
||||
# Differential Rovers
|
||||
|
||||
<Badge type="tip" text="PX4 v1.16" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
A differential rover's motion is controlled using a differential drive mechanism, where the left and right wheel speeds are adjusted independently to achieve the desired forward speed and yaw rate.
|
||||
Forward motion is achieved by driving both wheels at the same speed in the same direction.
|
||||
Rotation is achieved by driving the wheels at different speeds in opposite directions, allowing the rover to turn on the spot.
|
||||
|
||||
|
||||
|
||||
See [Configuration/Tuning](../config_rover/differential.md) to set up your rover and [Drive Modes](../flight_modes_rover/differential.md) for the supported flight (aka drive) modes.
|
||||
@@ -1,116 +0,0 @@
|
||||
# Differential-steering Rovers
|
||||
|
||||
<Badge type="tip" text="main (PX4 v1.16+)" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
:::warning
|
||||
Support for rover is [experimental](../airframes/index.md#experimental-vehicles).
|
||||
Maintainer volunteers, [contribution](../contribute/index.md) of new features, new frame configurations, or other improvements would all be very welcome!
|
||||
:::
|
||||
|
||||
A differential-steering rover's motion is controlled using a differential drive mechanism, where the left and right wheel speeds are adjusted independently to achieve the desired forward speed and yaw rate.
|
||||
|
||||
Forward motion is achieved by driving both wheels at the same speed in the same direction.
|
||||
Rotation is achieved by driving the wheels at different speeds in opposite directions, allowing the rover to turn on the spot.
|
||||
|
||||
|
||||
|
||||
## Basic Setup
|
||||
|
||||
To start using the differential-steering rover:
|
||||
|
||||
1. Enable the module by flashing the [PX4 rover build](../frames_rover/index.md#flashing-the-rover-build) onto your flight controller.
|
||||
|
||||
2. In the [Airframe](../config/airframe.md) configuration select the _Generic Rover Differential_:
|
||||
|
||||
|
||||
|
||||
Select the **Apply and Restart** button.
|
||||
|
||||
::: info
|
||||
If this airframe does not show up in the UI, it can alternatively be selected by setting the [SYS_AUTOSTART](../advanced_config/parameter_reference.md#SYS_AUTOSTART) parameter to `50000`.
|
||||
|
||||
:::
|
||||
|
||||
3. Open the [Actuators Configuration & Testing](../config/actuators.md) to map the motor functions to flight controller outputs.
|
||||
|
||||
This is sufficient to drive the the rover in [manual mode](../flight_modes_rover/index.md#manual-mode) (see [Flight modes](../flight_modes_rover/index.md)).
|
||||
|
||||
:::info
|
||||
The parameter [RD_MAN_YAW_SCALE](../advanced_config/parameter_reference.md#RD_MAN_YAW_SCALE) can be used to scale the manual input for the yaw rate.
|
||||
:::
|
||||
|
||||
## Tuning (Basic)
|
||||
|
||||
This section goes through the basic parameters that need to be set to use all other features for the differential-steering rover.
|
||||
Navigate to [Parameters](../advanced_config/parameters.md) in QGroundControl and set the following parameters:
|
||||
|
||||
1. [RD_WHEEL_TRACK](../advanced_config/parameter_reference.md#RD_WHEEL_TRACK) [m]: Measure the distance from the center of the right wheel to the center of the left wheel.
|
||||
|
||||
|
||||
|
||||
2. [RD_MAX_SPEED](../advanced_config/parameter_reference.md#RD_MAX_SPEED) [m/s]: In manual mode, drive the rover with full throttle and enter the observed speed as the parameter.
|
||||
|
||||
3. [RD_MAX_YAW_RATE](../advanced_config/parameter_reference.md#RD_MAX_YAW_RATE) [deg/s]: This is the maximum yaw rate you want to allow for your rover.
|
||||
This will define the stick-to-yaw-rate mapping in acro mode as well as setting an upper limit for the yaw rate in mission mode.
|
||||
|
||||
4. [RD_YAW_RATE_P](../advanced_config/parameter_reference.md#RD_YAW_RATE_P) and [RD_YAW_RATE_I](../advanced_config/parameter_reference.md#RD_YAW_RATE_I) [-]: Tuning parameters for the closed-loop yaw rate controller.
|
||||
|
||||
::: info
|
||||
This can be tuned by setting all previous parameters and then setting the rover to _acro mode_.
|
||||
Use the right stick to yaw the rover on the spot and then observe the desired and actual yaw rate in the flight log.
|
||||
Change parameters and iterate.
|
||||
|
||||
Suggestion: Start the tuning process with [RD_YAW_RATE_I](../advanced_config/parameter_reference.md#RD_YAW_RATE_I) equal to zero and only set if necessary.
|
||||
|
||||
:::
|
||||
|
||||
This is enough to start using the rover in acro mode.
|
||||
To start driving mission the parameters in [Tuning (Mission)](#tuning-mission) also must be set.
|
||||
|
||||
## Tuning (Mission)
|
||||
|
||||
:::warning
|
||||
The parameters in [Tuning (Basic)](#tuning-basic) must also be set to drive missions!
|
||||
:::
|
||||
|
||||
The module uses a control algorithm called pure pursuit, see [Mission Mode](../flight_modes_rover/index.md#mission-mode) for the basic tuning process.
|
||||
The additional parameters are separated into the following sections:
|
||||
|
||||
### Mission Velocity
|
||||
|
||||
These parameters tune velocity control in missions:
|
||||
|
||||
- [RD_MISS_SPD_DEF](#RD_MISS_SPD_DEF): Sets the default velocity ($m/s$) for the rover during the mission.
|
||||
- [RD_MAX_ACCEL](#RD_MAX_ACCEL) ($m/s^2$) and [RD_MAX_JERK](#RD_MAX_JERK) ($m/s^3$) are used to calculate a velocity trajectory such that the rover comes to a smooth stop as it reaches a waypoint.
|
||||
- [RD_SPEED_P](#RD_SPEED_P) and [RD_SPEED_I](#RD_SPEED_I) are used to tune the closed-loop velocity controller during missions.
|
||||
|
||||
### Yaw Rate
|
||||
|
||||
The yaw rate setpoint is calculated by using the heading error calculated by the pure pursuit algorithm for a PID controller that can be tuned with [RD_HEADING_P](#RD_HEADING_P) and [RD_HEADING_I](#RD_HEADING_I).
|
||||
|
||||
:::info
|
||||
There is some degree of overlap between this tuning and the pure pursuit controller gain set in [Mission Mode](../flight_modes_rover/index.md#mission-mode) as they both have an influence on how aggressive the rover will steer.
|
||||
:::
|
||||
|
||||
### State Machine
|
||||
|
||||
The module employs the following state machine to make full use of a differential-steering rovers ability to turn on the spot:
|
||||
|
||||
|
||||
These transition thresholds can be set with [RD_TRANS_DRV_TRN](#RD_TRANS_DRV_TRN) and [RD_TRANS_TRN_DRV](#RD_TRANS_TRN_DRV).
|
||||
|
||||
### Parameters
|
||||
|
||||
The following parameters affect the differential-steering rover in mission mode (overview):
|
||||
|
||||
| Parameter | Description | Unit |
|
||||
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------- | ------- |
|
||||
| <a id="RD_MISS_SPD_DEF"></a>[RD_MISS_SPD_DEF](../advanced_config/parameter_reference.md#RD_MISS_SPD_DEF) | Mission speed for the rover | $m/s$ |
|
||||
| <a id="RD_MAX_ACCEL"></a>[RD_MAX_ACCEL](../advanced_config/parameter_reference.md#RD_MAX_ACCEL) | Maximum acceleration for the rover | $m/s^2$ |
|
||||
| <a id="RD_MAX_JERK"></a>[RD_MAX_JERK](../advanced_config/parameter_reference.md#RD_MAX_JERK) | Maximum jerk for the rover | $m/s^3$ |
|
||||
| <a id="RD_SPEED_P"></a>[RD_SPEED_P](../advanced_config/parameter_reference.md#RD_SPEED_P) | Proportional gain for speed controller | - |
|
||||
| <a id="RD_SPEED_I"></a>[RD_SPEED_I](../advanced_config/parameter_reference.md#RD_SPEED_I) | Integral gain for speed controller | * |
|
||||
| <a id="RD_HEADING_P"></a>[RD_HEADING_P](../advanced_config/parameter_reference.md#RD_HEADING_P) | Proportional gain for heading controller | - |
|
||||
| <a id="RD_HEADING_I"></a>[RD_HEADING_I](../advanced_config/parameter_reference.md#RD_HEADING_I) | Integral gain for heading controller | * |
|
||||
| <a id="RD_TRANS_DRV_TRN"></a>[RD_TRANS_DRV_TRN](../advanced_config/parameter_reference.md#RD_TRANS_DRV_TRN) | Heading error threshold to switch from driving to spot turning | deg |
|
||||
| <a id="RD_TRANS_TRN_DRV"></a>[RD_TRANS_TRN_DRV](../advanced_config/parameter_reference.md#RD_TRANS_TRN_DRV) | Heading error threshold to switch from spot turning to driving | deg |
|
||||
@@ -1,10 +0,0 @@
|
||||
# Mecanum Rovers
|
||||
|
||||
<Badge type="tip" text="PX4 v1.16" /> <Badge type="warning" text="Experimental" />
|
||||
|
||||
A Mecanum rover is a type of mobile robot that uses Mecanum wheels to achieve omnidirectional movement. These wheels are unique because they have rollers mounted at a 45-degree angle around their circumference, allowing the rover to move not only forward and backward but also side-to-side and diagonally without needing to rotate first.
|
||||
Each wheel is driven by its own motor, and by controlling the speed and direction of each motor, the rover can move in any direction or spin in place.
|
||||
|
||||
|
||||
|
||||
See [Configuration/Tuning](../config_rover/mecanum.md) to set up your rover and [Drive Modes](../flight_modes_rover/mecanum.md) for the supported flight (aka drive) modes.
|
||||
@@ -1,15 +0,0 @@
|
||||
# Buffer128 (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/Buffer128.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 len # length of data
|
||||
uint32 MAX_BUFLEN = 128
|
||||
|
||||
uint8[128] data # data
|
||||
|
||||
# TOPICS voxl2_io_data
|
||||
|
||||
```
|
||||
@@ -1,15 +0,0 @@
|
||||
# CollisionReport (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/CollisionReport.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
uint8 src
|
||||
uint32 id
|
||||
uint8 action
|
||||
uint8 threat_level
|
||||
float32 time_to_minimum_delta
|
||||
float32 altitude_minimum_delta
|
||||
float32 horizontal_minimum_delta
|
||||
|
||||
```
|
||||
@@ -1,15 +0,0 @@
|
||||
# DifferentialDriveSetpoint (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/DifferentialDriveSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 speed # [m/s] collective roll-off speed in body x-axis
|
||||
bool closed_loop_speed_control # true if speed is controlled using estimator feedback, false if direct feed-forward
|
||||
float32 yaw_rate # [rad/s] yaw rate
|
||||
bool closed_loop_yaw_rate_control # true if yaw rate is controlled using gyroscope feedback, false if direct feed-forward
|
||||
|
||||
# TOPICS differential_drive_setpoint differential_drive_control_output
|
||||
|
||||
```
|
||||
@@ -1,24 +0,0 @@
|
||||
# NpfgStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/NpfgStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 wind_est_valid # (boolean) true = wind estimate is valid and/or being used by controller (also indicates if wind est usage is disabled despite being valid)
|
||||
float32 lat_accel # resultant lateral acceleration reference [m/s^2]
|
||||
float32 lat_accel_ff # lateral acceleration demand only for maintaining curvature [m/s^2]
|
||||
float32 bearing_feas # bearing feasibility [0,1]
|
||||
float32 bearing_feas_on_track # on-track bearing feasibility [0,1]
|
||||
float32 signed_track_error # signed track error [m]
|
||||
float32 track_error_bound # track error bound [m]
|
||||
float32 airspeed_ref # (true) airspeed reference [m/s]
|
||||
float32 bearing # bearing angle [rad]
|
||||
float32 heading_ref # heading angle reference [rad]
|
||||
float32 min_ground_speed_ref # minimum forward ground speed reference [m/s]
|
||||
float32 adapted_period # adapted period (if auto-tuning enabled) [s]
|
||||
float32 p_gain # controller proportional gain [rad/s]
|
||||
float32 time_const # controller time constant [s]
|
||||
float32 can_run_factor # estimate of certainty of the correct functionality of the npfg roll setpoint in [0, 1]
|
||||
|
||||
```
|
||||
@@ -1,13 +0,0 @@
|
||||
# RoverAckermannGuidanceStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverAckermannGuidanceStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 lookahead_distance # [m] Lookahead distance of pure the pursuit controller
|
||||
float32 heading_error # [deg] Heading error of the pure pursuit controller
|
||||
|
||||
# TOPICS rover_ackermann_guidance_status
|
||||
|
||||
```
|
||||
@@ -1,16 +0,0 @@
|
||||
# RoverAckermannSetpoint (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverAckermannSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 forward_speed_setpoint # [m/s] Desired speed in body x direction. Positiv: forwards, Negativ: backwards
|
||||
float32 forward_speed_setpoint_normalized # [-1, 1] Desired normalized speed in body x direction. Positiv: forwards, Negativ: backwards
|
||||
float32 steering_setpoint # [rad] Desired steering angle
|
||||
float32 steering_setpoint_normalized # [-1, 1] Desired normalized steering angle
|
||||
float32 lateral_acceleration_setpoint # [m/s^2] Desired acceleration in body y direction. Positiv: right, Negativ: left.
|
||||
|
||||
# TOPICS rover_ackermann_setpoint
|
||||
|
||||
```
|
||||
@@ -1,18 +0,0 @@
|
||||
# RoverAckermannStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverAckermannStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 measured_forward_speed # [m/s] Measured speed in body x direction. Forwards: positiv, Backwards: negativ
|
||||
float32 adjusted_forward_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 steering_setpoint_normalized # [-1, 1] Normalized steering setpoint
|
||||
float32 adjusted_steering_setpoint_normalized # [-1, 1] Normalized steering setpoint after applying slew rate
|
||||
float32 measured_lateral_acceleration # [m/s^2] Measured acceleration in body y direction. Positiv: right, Negativ: left.
|
||||
float32 pid_throttle_integral # Integral of the PID for the closed loop speed controller
|
||||
float32 pid_lat_accel_integral # Integral of the PID for the closed loop lateral acceleration controller
|
||||
|
||||
# TOPICS rover_ackermann_status
|
||||
|
||||
```
|
||||
@@ -1,14 +0,0 @@
|
||||
# RoverDifferentialGuidanceStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverDifferentialGuidanceStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 lookahead_distance # [m] Lookahead distance of pure the pursuit controller
|
||||
float32 heading_error_deg # [deg] Heading error of the pure pursuit controller
|
||||
uint8 state_machine # Driving state of the rover [0: SPOT_TURNING, 1: DRIVING, 2: GOAL_REACHED]
|
||||
|
||||
# TOPICS rover_differential_guidance_status
|
||||
|
||||
```
|
||||
@@ -1,16 +0,0 @@
|
||||
# RoverDifferentialSetpoint (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverDifferentialSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 forward_speed_setpoint # [m/s] Desired forward speed for the rover
|
||||
float32 forward_speed_setpoint_normalized # [-1, 1] Normalized forward speed for the rover
|
||||
float32 yaw_rate_setpoint # [rad/s] Desired yaw rate for the rover (Overriden by yaw controller if yaw_setpoint is used)
|
||||
float32 speed_diff_setpoint_normalized # [-1, 1] Normalized speed difference between the left and right wheels
|
||||
float32 yaw_setpoint # [rad] Desired yaw (heading) for the rover
|
||||
|
||||
# TOPICS rover_differential_setpoint
|
||||
|
||||
```
|
||||
@@ -1,21 +0,0 @@
|
||||
# RoverDifferentialStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverDifferentialStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 measured_forward_speed # [m/s] Measured speed in body x direction. Forwards: positiv, Backwards: negativ
|
||||
float32 adjusted_forward_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 measured_yaw # [rad] Measured yaw
|
||||
float32 adjusted_yaw_setpoint # [rad] Yaw setpoint after applying slew rate
|
||||
float32 clyaw_yaw_rate_setpoint # [rad/s] Yaw rate setpoint output by the closed loop yaw controller
|
||||
float32 measured_yaw_rate # [rad/s] Measured yaw rate
|
||||
float32 adjusted_yaw_rate_setpoint # [rad/s] Yaw rate setpoint from the closed loop yaw controller
|
||||
float32 pid_yaw_integral # Integral of the PID for the closed loop yaw controller
|
||||
float32 pid_yaw_rate_integral # Integral of the PID for the closed loop yaw rate controller
|
||||
float32 pid_throttle_integral # Integral of the PID for the closed loop speed controller
|
||||
|
||||
# TOPICS rover_differential_status
|
||||
|
||||
```
|
||||
@@ -1,14 +0,0 @@
|
||||
# RoverMecanumGuidanceStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverMecanumGuidanceStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 lookahead_distance # [m] Lookahead distance of pure the pursuit controller
|
||||
float32 heading_error # [rad] Heading error of the pure pursuit controller
|
||||
float32 desired_speed # [m/s] Desired velocity magnitude (speed)
|
||||
|
||||
# TOPICS rover_mecanum_guidance_status
|
||||
|
||||
```
|
||||
@@ -1,18 +0,0 @@
|
||||
# RoverMecanumSetpoint (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverMecanumSetpoint.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 forward_speed_setpoint # [m/s] Desired forward speed
|
||||
float32 forward_speed_setpoint_normalized # [-1, 1] Desired normalized forward speed
|
||||
float32 lateral_speed_setpoint # [m/s] Desired lateral speed
|
||||
float32 lateral_speed_setpoint_normalized # [-1, 1] Desired normalized lateral speed
|
||||
float32 yaw_rate_setpoint # [rad/s] Desired yaw rate
|
||||
float32 speed_diff_setpoint_normalized # [-1, 1] Normalized speed difference between the left and right wheels
|
||||
float32 yaw_setpoint # [rad] Desired yaw (heading)
|
||||
|
||||
# TOPICS rover_mecanum_setpoint
|
||||
|
||||
```
|
||||
@@ -1,24 +0,0 @@
|
||||
# RoverMecanumStatus (UORB message)
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/RoverMecanumStatus.msg)
|
||||
|
||||
```c
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32 measured_forward_speed # [m/s] Measured speed in body x direction. Positiv: forwards, Negativ: backwards
|
||||
float32 adjusted_forward_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 measured_lateral_speed # [m/s] Measured speed in body y direction. Positiv: right, Negativ: left
|
||||
float32 adjusted_lateral_speed_setpoint # [m/s] Speed setpoint after applying slew rate
|
||||
float32 measured_yaw_rate # [rad/s] Measured yaw rate
|
||||
float32 clyaw_yaw_rate_setpoint # [rad/s] Yaw rate setpoint output by the closed loop yaw controller
|
||||
float32 adjusted_yaw_rate_setpoint # [rad/s] Yaw rate setpoint from the closed loop yaw controller
|
||||
float32 measured_yaw # [rad] Measured yaw
|
||||
float32 adjusted_yaw_setpoint # [rad] Yaw setpoint after applying slew rate
|
||||
float32 pid_yaw_rate_integral # Integral of the PID for the closed loop yaw rate controller
|
||||
float32 pid_yaw_integral # Integral of the PID for the closed loop yaw controller
|
||||
float32 pid_forward_throttle_integral # Integral of the PID for the closed loop forward speed controller
|
||||
float32 pid_lateral_throttle_integral # Integral of the PID for the closed loop lateral speed controller
|
||||
|
||||
# TOPICS rover_mecanum_status
|
||||
|
||||
```
|
||||
@@ -1,18 +0,0 @@
|
||||
# TrajectoryBezier (UORB message)
|
||||
|
||||
Bezier Trajectory description. See also Mavlink TRAJECTORY msg
|
||||
The topic trajectory_bezier describe each waypoint defined in vehicle_trajectory_bezier
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/TrajectoryBezier.msg)
|
||||
|
||||
```c
|
||||
# Bezier Trajectory description. See also Mavlink TRAJECTORY msg
|
||||
# The topic trajectory_bezier describe each waypoint defined in vehicle_trajectory_bezier
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32[3] position # local position x,y,z (metres)
|
||||
float32 yaw # yaw angle (rad)
|
||||
float32 delta # time it should take to get to this waypoint, if this is the final waypoint (seconds)
|
||||
|
||||
```
|
||||
@@ -1,23 +0,0 @@
|
||||
# TrajectoryWaypoint (UORB message)
|
||||
|
||||
Waypoint Trajectory description. See also Mavlink TRAJECTORY msg
|
||||
The topic trajectory_waypoint describe each waypoint defined in vehicle_trajectory_waypoint
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/TrajectoryWaypoint.msg)
|
||||
|
||||
```c
|
||||
# Waypoint Trajectory description. See also Mavlink TRAJECTORY msg
|
||||
# The topic trajectory_waypoint describe each waypoint defined in vehicle_trajectory_waypoint
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
float32[3] position
|
||||
float32[3] velocity
|
||||
float32[3] acceleration
|
||||
float32 yaw
|
||||
float32 yaw_speed
|
||||
|
||||
bool point_valid
|
||||
uint8 type
|
||||
|
||||
```
|
||||
@@ -1,29 +0,0 @@
|
||||
# VehicleTrajectoryBezier (UORB message)
|
||||
|
||||
Vehicle Waypoints Trajectory description. See also MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
The topic vehicle_trajectory_bezier is used to send a smooth flight path from the
|
||||
companion computer / avoidance module to the position controller.
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/VehicleTrajectoryBezier.msg)
|
||||
|
||||
```c
|
||||
# Vehicle Waypoints Trajectory description. See also MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
# The topic vehicle_trajectory_bezier is used to send a smooth flight path from the
|
||||
# companion computer / avoidance module to the position controller.
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 POINT_0 = 0
|
||||
uint8 POINT_1 = 1
|
||||
uint8 POINT_2 = 2
|
||||
uint8 POINT_3 = 3
|
||||
uint8 POINT_4 = 4
|
||||
|
||||
uint8 NUMBER_POINTS = 5
|
||||
|
||||
TrajectoryBezier[5] control_points
|
||||
uint8 bezier_order
|
||||
|
||||
# TOPICS vehicle_trajectory_bezier
|
||||
|
||||
```
|
||||
@@ -1,32 +0,0 @@
|
||||
# VehicleTrajectoryWaypoint (UORB message)
|
||||
|
||||
Vehicle Waypoints Trajectory description. See also MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
The topic vehicle_trajectory_waypoint_desired is used to send the user desired waypoints from the position controller to the companion computer / avoidance module.
|
||||
The topic vehicle_trajectory_waypoint is used to send the adjusted waypoints from the companion computer / avoidance module to the position controller.
|
||||
|
||||
[source file](https://github.com/PX4/PX4-Autopilot/blob/main/msg/VehicleTrajectoryWaypoint.msg)
|
||||
|
||||
```c
|
||||
# Vehicle Waypoints Trajectory description. See also MAVLink MAV_TRAJECTORY_REPRESENTATION msg
|
||||
# The topic vehicle_trajectory_waypoint_desired is used to send the user desired waypoints from the position controller to the companion computer / avoidance module.
|
||||
# The topic vehicle_trajectory_waypoint is used to send the adjusted waypoints from the companion computer / avoidance module to the position controller.
|
||||
|
||||
uint64 timestamp # time since system start (microseconds)
|
||||
|
||||
uint8 MAV_TRAJECTORY_REPRESENTATION_WAYPOINTS = 0
|
||||
|
||||
uint8 type # Type from MAV_TRAJECTORY_REPRESENTATION enum.
|
||||
|
||||
uint8 POINT_0 = 0
|
||||
uint8 POINT_1 = 1
|
||||
uint8 POINT_2 = 2
|
||||
uint8 POINT_3 = 3
|
||||
uint8 POINT_4 = 4
|
||||
|
||||
uint8 NUMBER_POINTS = 5
|
||||
|
||||
TrajectoryWaypoint[5] waypoints
|
||||
|
||||
# TOPICS vehicle_trajectory_waypoint vehicle_trajectory_waypoint_desired
|
||||
|
||||
```
|
||||
Reference in New Issue
Block a user