ardupilot/ArduCopter/heli_control_stabilize.pde

/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
#if FRAME_CONFIG == HELI_FRAME
/*
 * heli_control_stabilize.pde - init and run calls for stabilize flight mode for trad heli
 */

// stabilize_init - initialise stabilize controller
static bool heli_stabilize_init(bool ignore_checks)
{
    // set target altitude to zero for reporting
    // To-Do: make pos controller aware when it's active/inactive so it can always report the altitude error?
    pos_control.set_alt_target(0);
    return true;
}

// stabilize_run - runs the main stabilize controller
// should be called at 100hz or more
static void heli_stabilize_run()
{
    float target_roll, target_pitch;
    float target_yaw_rate;
    int16_t pilot_throttle_scaled;

    // Tradheli should not reset roll, pitch, yaw targets when motors are not runup, because
    // we may be in autorotation flight.  These should be reset only when transitioning from disarmed
    // to armed, because the pilot will have placed the helicopter down on the landing pad.  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
    
    if(!motors.armed()) {
        heli_flags.init_targets_on_arming=true;
        attitude_control.set_yaw_target_to_current_heading();
    }
    
    if(motors.armed() && heli_flags.init_targets_on_arming) {
        heli_flags.init_targets_on_arming=false;
        attitude_control.relax_bf_rate_controller();
    }

    // send RC inputs direct into motors library for use during manual passthrough for helicopter setup
    heli_radio_passthrough();

    // apply SIMPLE mode transform to pilot inputs
    update_simple_mode();

    // convert pilot input to lean angles
    // To-Do: convert get_pilot_desired_lean_angles to return angles as floats
    get_pilot_desired_lean_angles(channel_roll->control_in, channel_pitch->control_in, target_roll, target_pitch);

    // get pilot's desired yaw rate
    target_yaw_rate = get_pilot_desired_yaw_rate(channel_yaw->control_in);

    // get pilot's desired throttle
    pilot_throttle_scaled = get_pilot_desired_collective(channel_throttle->control_in);

    // call attitude controller
    attitude_control.angle_ef_roll_pitch_rate_ef_yaw_smooth(target_roll, target_pitch, target_yaw_rate, get_smoothing_gain());

    // output pilot's throttle - note that TradHeli does not used angle-boost
    attitude_control.set_throttle_out(pilot_throttle_scaled, false, g.throttle_filt);
}

#endif  //HELI_FRAME