ardupilot/ArduCopter/mode_acro_heli.cpp

#include "Copter.h"

#if MODE_ACRO_ENABLED

#if FRAME_CONFIG == HELI_FRAME
/*
 * Init and run calls for acro flight mode for trad heli
 */

// heli_acro_init - initialise acro controller
bool ModeAcro_Heli::init(bool ignore_checks)
{
    // set stab collective false to use full collective pitch range
    copter.input_manager.set_use_stab_col(false);

    // always successfully enter acro
    return true;
}

// heli_acro_run - runs the acro controller
// should be called at 100hz or more
void ModeAcro_Heli::run()
{
    float target_roll_rads, target_pitch_rads, target_yaw_rads;
    float pilot_throttle_scaled;

    // Tradheli should not reset roll, pitch, yaw targets when motors are not runup while flying, because
    // we may be in autorotation flight.  This is so that the servos move in a realistic fashion while disarmed
    // for operational checks. Also, unlike multicopters we do not set throttle (i.e. collective pitch) to zero
    // so the swash servos move.

    // Request throttle unlimited. The setter enforces safety constraints:
    // - Disarmed: held at SHUT_DOWN until armed
    // - Armed without interlock: limited to GROUND_IDLE (swash can move, rotor stopped)
    // - Armed with interlock: THROTTLE_UNLIMITED granted
    motors->set_desired_spool_state(AP_Motors::DesiredSpoolState::THROTTLE_UNLIMITED);

    switch (motors->get_spool_state()) {
    case AP_Motors::SpoolState::SHUT_DOWN:
        // Motors Stopped
        attitude_control->reset_target_and_rate(false);
        attitude_control->reset_rate_controller_I_terms();
        break;
    case AP_Motors::SpoolState::GROUND_IDLE:
        // If aircraft is landed, set target heading to current and reset the integrator
        // Otherwise motors could be at ground idle for practice autorotation
        if ((motors->init_targets_on_arming() && motors->using_leaky_integrator()) || (copter.ap.land_complete && !motors->using_leaky_integrator())) {
            attitude_control->reset_target_and_rate(false);
            attitude_control->reset_rate_controller_I_terms_smoothly();
        }
        break;
    case AP_Motors::SpoolState::THROTTLE_UNLIMITED:
        if (copter.ap.land_complete && !motors->using_leaky_integrator()) {
            attitude_control->reset_rate_controller_I_terms_smoothly();
        }
        break;
    case AP_Motors::SpoolState::SPOOLING_UP:
    case AP_Motors::SpoolState::SPOOLING_DOWN:
        // do nothing
        break;
    }

    // convert the input to the desired body frame rate
    get_pilot_desired_rates_rads(target_roll_rads, target_pitch_rads, target_yaw_rads);
    // only mimic flybar response when trainer mode is disabled
    if ((Trainer)g.acro_trainer.get() == Trainer::OFF) {
        // while landed always leak off target attitude to current attitude
        if (copter.ap.land_complete) {
            virtual_flybar(target_roll_rads, target_pitch_rads, target_yaw_rads, 3.0f, 3.0f);
        // while flying use acro balance parameters for leak rate
        } else {
            virtual_flybar(target_roll_rads, target_pitch_rads, target_yaw_rads, g.acro_balance_pitch, g.acro_balance_roll);
        }
    }

    // run attitude controller
    if (g2.acro_options.get() & uint8_t(AcroOptions::RATE_LOOP_ONLY)) {
        attitude_control->input_rate_bf_roll_pitch_yaw_2_rads(target_roll_rads, target_pitch_rads, target_yaw_rads);
    } else {
        attitude_control->input_rate_bf_roll_pitch_yaw_rads(target_roll_rads, target_pitch_rads, target_yaw_rads);
    }

    // get pilot's desired throttle
    pilot_throttle_scaled = copter.input_manager.get_pilot_desired_collective(channel_throttle->get_control_in());

    // output pilot's throttle without angle boost
    attitude_control->set_throttle_out(pilot_throttle_scaled, false, g.throttle_filt);
}


// virtual_flybar - acts like a flybar by leaking target atttitude back to current attitude
void ModeAcro_Heli::virtual_flybar( float &roll_out_rads, float &pitch_out_rads, float &yaw_out_rads, float pitch_leak, float roll_leak)
{
    Vector3f rate_ef_level_rads, rate_bf_level_rads;

    // get attitude targets
    const Vector3f& att_target_rad = attitude_control->get_att_target_euler_rad();

    // Calculate earth frame rate command for roll leak to current attitude
    rate_ef_level_rads.x = -wrap_PI(att_target_rad.x - ahrs.get_roll_rad()) * roll_leak;

    // Calculate earth frame rate command for pitch leak to current attitude
    rate_ef_level_rads.y = -wrap_PI(att_target_rad.y - ahrs.get_pitch_rad()) * pitch_leak;

    // Calculate earth frame rate command for yaw
    rate_ef_level_rads.z = 0;

    // convert earth-frame leak rates to body-frame leak rates
    attitude_control->euler_derivative_to_body(attitude_control->get_attitude_target_quat(), rate_ef_level_rads, rate_bf_level_rads);

    // combine earth frame rate corrections with rate requests
    roll_out_rads += rate_bf_level_rads.x;
    pitch_out_rads += rate_bf_level_rads.y;
    yaw_out_rads += rate_bf_level_rads.z;

}
#endif  //HELI_FRAME
#endif  //MODE_ACRO_ENABLED