Files
ODrive/Firmware/MotorControl/low_level.cpp
T

439 lines
17 KiB
C++

/* Includes ------------------------------------------------------------------*/
// Because of broken cmsis_os.h, we need to include arm_math first,
// otherwise chip specific defines are ommited
#include <stm32f405xx.h>
#include <stm32f4xx_hal.h> // Sets up the correct chip specifc defines required by arm_math
#define ARM_MATH_CM4
#include <arm_math.h>
#include <cmsis_os.h>
#include <math.h>
#include <stdint.h>
#include <stdlib.h>
#include <adc.h>
#include <gpio.h>
#include <main.h>
#include <spi.h>
#include <tim.h>
#include <utils.h>
#include "odrive_main.h"
/* Private defines -----------------------------------------------------------*/
// #define DEBUG_PRINT
/* Private macros ------------------------------------------------------------*/
/* Private typedef -----------------------------------------------------------*/
/* Global constant data ------------------------------------------------------*/
/* Global variables ----------------------------------------------------------*/
// This value is updated by the DC-bus reading ADC.
// Arbitrary non-zero inital value to avoid division by zero if ADC reading is late
float vbus_voltage = 12.0f;
bool brake_resistor_armed_ = false;
/* Private constant data -----------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* CPU critical section helpers ----------------------------------------------*/
static inline uint8_t cpu_enter_critical() {
uint8_t status_register;
asm (
"MRS R0, PRIMASK\n\t"
"CPSID I\n\t"
"STRB R0, %[output]"
: [output] "=m" (status_register) :: "r0"
);
return status_register;
}
static inline void cpu_exit_critical(uint8_t status_register) {
asm (
"ldrb r0, %[input]\n\t"
"msr PRIMASK,r0;\n\t"
::[input] "m" (status_register) : "r0"
);
}
/* Safety critical functions -------------------------------------------------*/
/*
* This section contains all accesses to safety critical hardware registers.
* Specifically, these registers:
* Motor0 PWMs:
* Timer1.MOE (master output enabled)
* Timer1.CCR1 (counter compare register 1)
* Timer1.CCR2 (counter compare register 2)
* Timer1.CCR3 (counter compare register 3)
* Motor1 PWMs:
* Timer8.MOE (master output enabled)
* Timer8.CCR1 (counter compare register 1)
* Timer8.CCR2 (counter compare register 2)
* Timer8.CCR3 (counter compare register 3)
* Brake resistor PWM:
* Timer2.CCR3 (counter compare register 3)
* Timer2.CCR4 (counter compare register 4)
*
* The following assumptions are made:
* - The hardware operates as described in the datasheet:
* http://www.st.com/content/ccc/resource/technical/document/reference_manual/3d/6d/5a/66/b4/99/40/d4/DM00031020.pdf/files/DM00031020.pdf/jcr:content/translations/en.DM00031020.pdf
* This assumption also requires for instance that there are no radiation
* caused hardware errors.
* - After startup, all variables used in this section are exclusively modified
* by the code in this section (this excludes function parameters)
* This assumption also requires that there is no memory corruption.
* - This code is compiled by a C standard compliant compiler.
*
* Furthermore:
* - Between calls to safety_critical_arm_motor_pwm and
* safety_critical_disarm_motor_pwm the motor's Ibus current is
* set to the correct value and update_brake_resistor is called
* at a high rate.
*/
// @brief Kicks off the arming process of the motor.
// All calls to this function must clearly originate
// from user input.
void safety_critical_arm_motor_pwm(Motor& motor) {
uint8_t sr = cpu_enter_critical();
if (brake_resistor_armed_) {
motor.armed_state_ = Motor::ARMED_STATE_WAITING_FOR_TIMINGS;
}
cpu_exit_critical(sr);
}
// @brief Disarms the motor PWM.
// After calling this function, it is guaranteed that all three
// motor phases are floating and will not be enabled again until
// safety_critical_arm_motor_phases is called.
// @returns true if the motor was in a state other than disarmed before
bool safety_critical_disarm_motor_pwm(Motor& motor) {
uint8_t sr = cpu_enter_critical();
bool was_armed = motor.armed_state_ != Motor::ARMED_STATE_DISARMED;
motor.armed_state_ = Motor::ARMED_STATE_DISARMED;
__HAL_TIM_MOE_DISABLE_UNCONDITIONALLY(motor.hw_config_.timer);
cpu_exit_critical(sr);
return was_armed;
}
// @brief Updates the phase timings unless the motor is disarmed.
//
// If this is called at a rate higher than the motor's timer period,
// the actual PMW timings on the pins can be undefined for up to one
// timer period.
void safety_critical_apply_motor_pwm_timings(Motor& motor, uint16_t timings[3]) {
uint8_t sr = cpu_enter_critical();
if (!brake_resistor_armed_) {
motor.armed_state_ = Motor::ARMED_STATE_ARMED;
}
motor.hw_config_.timer->Instance->CCR1 = timings[0];
motor.hw_config_.timer->Instance->CCR2 = timings[1];
motor.hw_config_.timer->Instance->CCR3 = timings[2];
if (motor.armed_state_ == Motor::ARMED_STATE_WAITING_FOR_TIMINGS) {
// timings were just loaded into the timer registers
// the timer register are buffered, so they won't have an effect
// on the output just yet so we need to wait until the next
// interrupt before we actually enable the output
motor.armed_state_ = Motor::ARMED_STATE_WAITING_FOR_UPDATE;
} else if (motor.armed_state_ == Motor::ARMED_STATE_WAITING_FOR_UPDATE) {
// now we waited long enough. Enter armed state and
// enable the actual PWM outputs.
motor.armed_state_ = Motor::ARMED_STATE_ARMED;
__HAL_TIM_MOE_ENABLE(motor.hw_config_.timer); // enable pwm outputs
} else if (motor.armed_state_ == Motor::ARMED_STATE_ARMED) {
// nothing to do, PWM is running, all good
} else {
// unknown state oh no
safety_critical_disarm_motor_pwm(motor);
}
cpu_exit_critical(sr);
}
// @brief Arms the brake resistor
void safety_critical_arm_brake_resistor() {
uint8_t sr = cpu_enter_critical();
brake_resistor_armed_ = true;
htim2.Instance->CCR3 = 0;
htim2.Instance->CCR4 = TIM_APB1_PERIOD_CLOCKS + 1;
cpu_exit_critical(sr);
}
// @brief Disarms the brake resistor and by extension
// all motor PWM outputs.
// After calling this, the brake resistor can only be armed again
// by calling safety_critical_arm_brake_resistor().
void safety_critical_disarm_brake_resistor() {
uint8_t sr = cpu_enter_critical();
brake_resistor_armed_ = false;
htim2.Instance->CCR3 = 0;
htim2.Instance->CCR4 = TIM_APB1_PERIOD_CLOCKS + 1;
for (size_t i = 0; i < AXIS_COUNT; ++i) {
safety_critical_disarm_motor_pwm(axes[i]->motor_);
}
cpu_exit_critical(sr);
}
// @brief Updates the brake resistor PWM timings unless
// the brake resistor is disarmed.
void safety_critical_apply_brake_resistor_timings(uint32_t low_off, uint32_t high_on) {
uint8_t sr = cpu_enter_critical();
if (brake_resistor_armed_) {
// Safe update of low and high side timings
// To avoid race condition, first reset timings to safe state
// ch3 is low side, ch4 is high side
htim2.Instance->CCR3 = 0;
htim2.Instance->CCR4 = TIM_APB1_PERIOD_CLOCKS + 1;
htim2.Instance->CCR3 = low_off;
htim2.Instance->CCR4 = high_on;
}
cpu_exit_critical(sr);
}
/* Function implementations --------------------------------------------------*/
void start_adc_pwm() {
// Enable ADC and interrupts
__HAL_ADC_ENABLE(&hadc1);
__HAL_ADC_ENABLE(&hadc2);
__HAL_ADC_ENABLE(&hadc3);
// Warp field stabilize.
osDelay(2);
__HAL_ADC_ENABLE_IT(&hadc1, ADC_IT_JEOC);
__HAL_ADC_ENABLE_IT(&hadc2, ADC_IT_JEOC);
__HAL_ADC_ENABLE_IT(&hadc3, ADC_IT_JEOC);
__HAL_ADC_ENABLE_IT(&hadc2, ADC_IT_EOC);
__HAL_ADC_ENABLE_IT(&hadc3, ADC_IT_EOC);
// Ensure that debug halting of the core doesn't leave the motor PWM running
__HAL_DBGMCU_FREEZE_TIM1();
__HAL_DBGMCU_FREEZE_TIM8();
start_pwm(&htim1);
start_pwm(&htim8);
// TODO: explain why this offset
sync_timers(&htim1, &htim8, TIM_CLOCKSOURCE_ITR0, TIM_1_8_PERIOD_CLOCKS / 2 - 1 * 128);
// Motor output starts in the disabled state
__HAL_TIM_MOE_DISABLE_UNCONDITIONALLY(&htim1);
__HAL_TIM_MOE_DISABLE_UNCONDITIONALLY(&htim8);
// Start brake resistor PWM in floating output configuration
htim2.Instance->CCR3 = 0;
htim2.Instance->CCR4 = TIM_APB1_PERIOD_CLOCKS + 1;
HAL_TIM_PWM_Start(&htim2, TIM_CHANNEL_3);
HAL_TIM_PWM_Start(&htim2, TIM_CHANNEL_4);
// Disarm motors and arm brake resistor
for (size_t i = 0; i < AXIS_COUNT; ++i) {
safety_critical_disarm_motor_pwm(axes[i]->motor_);
}
safety_critical_arm_brake_resistor();
}
void start_pwm(TIM_HandleTypeDef* htim) {
// Init PWM
int half_load = TIM_1_8_PERIOD_CLOCKS / 2;
htim->Instance->CCR1 = half_load;
htim->Instance->CCR2 = half_load;
htim->Instance->CCR3 = half_load;
// This hardware obfustication layer really is getting on my nerves
HAL_TIM_PWM_Start(htim, TIM_CHANNEL_1);
HAL_TIMEx_PWMN_Start(htim, TIM_CHANNEL_1);
HAL_TIM_PWM_Start(htim, TIM_CHANNEL_2);
HAL_TIMEx_PWMN_Start(htim, TIM_CHANNEL_2);
HAL_TIM_PWM_Start(htim, TIM_CHANNEL_3);
HAL_TIMEx_PWMN_Start(htim, TIM_CHANNEL_3);
htim->Instance->CCR4 = 1;
HAL_TIM_PWM_Start_IT(htim, TIM_CHANNEL_4);
}
void sync_timers(TIM_HandleTypeDef* htim_a, TIM_HandleTypeDef* htim_b,
uint16_t TIM_CLOCKSOURCE_ITRx, uint16_t count_offset) {
// Store intial timer configs
uint16_t MOE_store_a = htim_a->Instance->BDTR & (TIM_BDTR_MOE);
uint16_t MOE_store_b = htim_b->Instance->BDTR & (TIM_BDTR_MOE);
uint16_t CR2_store = htim_a->Instance->CR2;
uint16_t SMCR_store = htim_b->Instance->SMCR;
// Turn off output
htim_a->Instance->BDTR &= ~(TIM_BDTR_MOE);
htim_b->Instance->BDTR &= ~(TIM_BDTR_MOE);
// Disable both timer counters
htim_a->Instance->CR1 &= ~TIM_CR1_CEN;
htim_b->Instance->CR1 &= ~TIM_CR1_CEN;
// Set first timer to send TRGO on counter enable
htim_a->Instance->CR2 &= ~TIM_CR2_MMS;
htim_a->Instance->CR2 |= TIM_TRGO_ENABLE;
// Set Trigger Source of second timer to the TRGO of the first timer
htim_b->Instance->SMCR &= ~TIM_SMCR_TS;
htim_b->Instance->SMCR |= TIM_CLOCKSOURCE_ITRx;
// Set 2nd timer to start on trigger
htim_b->Instance->SMCR &= ~TIM_SMCR_SMS;
htim_b->Instance->SMCR |= TIM_SLAVEMODE_TRIGGER;
// Dir bit is read only in center aligned mode, so we clear the mode for now
uint16_t CMS_store_a = htim_a->Instance->CR1 & TIM_CR1_CMS;
uint16_t CMS_store_b = htim_b->Instance->CR1 & TIM_CR1_CMS;
htim_a->Instance->CR1 &= ~TIM_CR1_CMS;
htim_b->Instance->CR1 &= ~TIM_CR1_CMS;
// Set both timers to up-counting state
htim_a->Instance->CR1 &= ~TIM_CR1_DIR;
htim_b->Instance->CR1 &= ~TIM_CR1_DIR;
// Restore center aligned mode
htim_a->Instance->CR1 |= CMS_store_a;
htim_b->Instance->CR1 |= CMS_store_b;
// set counter offset
htim_a->Instance->CNT = count_offset;
htim_b->Instance->CNT = 0;
// Start Timer a
htim_a->Instance->CR1 |= (TIM_CR1_CEN);
// Restore timer configs
htim_a->Instance->CR2 = CR2_store;
htim_b->Instance->SMCR = SMCR_store;
// restore output
htim_a->Instance->BDTR |= MOE_store_a;
htim_b->Instance->BDTR |= MOE_store_b;
}
// @brief Floats ALL phases immediately and disarms both motors and the brake resistor.
void low_level_fault(Motor::Error_t error) {
// Disable all motors NOW!
for (size_t i = 0; i < AXIS_COUNT; ++i) {
safety_critical_disarm_motor_pwm(axes[i]->motor_);
axes[i]->motor_.error_ |= error;
}
safety_critical_disarm_brake_resistor();
}
//--------------------------------
// IRQ Callbacks
//--------------------------------
void vbus_sense_adc_cb(ADC_HandleTypeDef* hadc, bool injected) {
static const float voltage_scale = 3.3f * VBUS_S_DIVIDER_RATIO / (float)(1 << 12);
// Only one conversion in sequence, so only rank1
uint32_t ADCValue = HAL_ADCEx_InjectedGetValue(hadc, ADC_INJECTED_RANK_1);
vbus_voltage = ADCValue * voltage_scale;
}
// This is the callback from the ADC that we expect after the PWM has triggered an ADC conversion.
// TODO: Document how the phasing is done, link to timing diagram
void pwm_trig_adc_cb(ADC_HandleTypeDef* hadc, bool injected) {
#define calib_tau 0.2f //@TOTO make more easily configurable
static const float calib_filter_k = CURRENT_MEAS_PERIOD / calib_tau;
// Ensure ADCs are expected ones to simplify the logic below
if (!(hadc == &hadc2 || hadc == &hadc3)) {
low_level_fault(Motor::ERROR_ADC_FAILED);
return;
};
// Motor 0 is on Timer 1, which triggers ADC 2 and 3 on an injected conversion
// Motor 1 is on Timer 8, which triggers ADC 2 and 3 on a regular conversion
// If the corresponding timer is counting up, we just sampled in SVM vector 0, i.e. real current
// If we are counting down, we just sampled in SVM vector 7, with zero current
Axis& axis = injected ? *axes[0] : *axes[1];
Axis& other_axis = injected ? *axes[1] : *axes[0];
bool counting_down = axis.motor_.hw_config_.timer->Instance->CR1 & TIM_CR1_DIR;
bool current_meas_not_DC_CAL = !counting_down;
bool update_timings = false;
if (hadc == &hadc2) {
if (&axis == axes[1] && counting_down)
update_timings = true; // update timings of M0
else if (&axis == axes[0] && !counting_down)
update_timings = true; // update timings of M1
}
// Load next timings for the motor that we're not currently sampling
if (update_timings) {
if (!other_axis.motor_.next_timings_valid_) {
// the motor control loop failed to update the timings in time
// we must assume that it died and therefore float all phases
bool was_armed = safety_critical_disarm_motor_pwm(other_axis.motor_);
if (was_armed) {
other_axis.motor_.error_ |= Motor::ERROR_CONTROL_DEADLINE_MISSED;
}
} else {
other_axis.motor_.next_timings_valid_ = false;
safety_critical_apply_motor_pwm_timings(
other_axis.motor_, other_axis.motor_.next_timings_
);
}
update_brake_current();
}
// Check the timing of the sequencing
if (current_meas_not_DC_CAL)
axis.motor_.log_timing(Motor::TIMING_LOG_ADC_CB_I);
else
axis.motor_.log_timing(Motor::TIMING_LOG_ADC_CB_DC);
uint32_t ADCValue;
if (injected) {
ADCValue = HAL_ADCEx_InjectedGetValue(hadc, ADC_INJECTED_RANK_1);
} else {
ADCValue = HAL_ADC_GetValue(hadc);
}
float current = axis.motor_.phase_current_from_adcval(ADCValue);
if (current_meas_not_DC_CAL) {
// ADC2 and ADC3 record the phB and phC currents concurrently,
// and their interrupts should arrive on the same clock cycle.
// We dispatch the callbacks in order, so ADC2 will always be processed before ADC3.
// Therefore we store the value from ADC2 and signal the thread that the
// measurement is ready when we receive the ADC3 measurement
// return or continue
if (hadc == &hadc2) {
axis.motor_.current_meas_.phB = current - axis.motor_.DC_calib_.phB;
return;
} else {
axis.motor_.current_meas_.phC = current - axis.motor_.DC_calib_.phC;
}
// Trigger axis thread
axis.signal_current_meas();
} else {
// DC_CAL measurement
if (hadc == &hadc2) {
axis.motor_.DC_calib_.phB += (current - axis.motor_.DC_calib_.phB) * calib_filter_k;
} else {
axis.motor_.DC_calib_.phC += (current - axis.motor_.DC_calib_.phC) * calib_filter_k;
}
}
}
// @brief Sums up the Ibus contribution of each motor and updates the
// brake resistor PWM accordingly.
void update_brake_current() {
float Ibus_sum = 0.0f;
for (size_t i = 0; i < AXIS_COUNT; ++i) {
if (axes[i]->motor_.armed_state_ == Motor::ARMED_STATE_ARMED) {
Ibus_sum += axes[i]->motor_.current_control_.Ibus;
}
}
float brake_current = -Ibus_sum;
// Clip negative values to 0.0f
if (brake_current < 0.0f) brake_current = 0.0f;
float brake_duty = brake_current * board_config.brake_resistance / vbus_voltage;
// Duty limit at 90% to allow bootstrap caps to charge
// If brake_duty is NaN, this expression will also evaluate to true
if ((brake_duty >= 0.0f) && (brake_duty <= 0.9f)) {
int high_on = static_cast<int>(TIM_APB1_PERIOD_CLOCKS * (1.0f - brake_duty));
int low_off = high_on - TIM_APB1_DEADTIME_CLOCKS;
if (low_off < 0) low_off = 0;
safety_critical_apply_brake_resistor_timings(low_off, high_on);
} else {
safety_critical_disarm_brake_resistor();
}
}