ardupilot/APMrover2/mode_acro.cpp

#include "mode.h"
#include "Rover.h"

void ModeAcro::update()
{
    // get speed forward
    float speed, desired_steering;
    if (!attitude_control.get_forward_speed(speed)) {
        float desired_throttle;
        // convert pilot stick input into desired steering and throttle
        get_pilot_desired_steering_and_throttle(desired_steering, desired_throttle);
        // no valid speed, just use the provided throttle
        g2.motors.set_throttle(desired_throttle);
        // set reverse flag if negative throttle
        rover.set_reverse(is_negative(desired_throttle));
    } else {
        float desired_speed;
        // convert pilot stick input into desired steering and speed
        get_pilot_desired_steering_and_speed(desired_steering, desired_speed);
        calc_throttle(desired_speed, false, true);
        // set reverse flag if negative desired speed
        rover.set_reverse(is_negative(desired_speed));
    }

    // convert pilot steering input to desired turn rate in radians/sec
    const float target_turn_rate = (desired_steering / 4500.0f) * radians(g2.acro_turn_rate);

    // run steering turn rate controller and throttle controller
    const float steering_out = attitude_control.get_steering_out_rate(
                                                                    target_turn_rate,
                                                                    g2.motors.limit.steer_left,
                                                                    g2.motors.limit.steer_right);

    g2.motors.set_steering(steering_out * 4500.0f);
}

bool ModeAcro::requires_velocity() const
{
    return g2.motors.have_skid_steering()? false: true;
}