ardupilot/ArduSub/control_surface.cpp

#include "Sub.h"


bool Sub::surface_init(bool ignore_checks)
{

	if(!ap.depth_sensor_present) { // can't hold depth without a depth sensor, exit immediately.
		gcs_send_text(MAV_SEVERITY_WARNING, "Surface mode requires external pressure sensor.");
		return false;
	}

    // initialize vertical speeds and leash lengths
    pos_control.set_speed_z(wp_nav.get_speed_down(), wp_nav.get_speed_up());
    pos_control.set_accel_z(wp_nav.get_accel_z());

    // initialise position and desired velocity
    pos_control.set_alt_target(inertial_nav.get_altitude());
    pos_control.set_desired_velocity_z(inertial_nav.get_velocity_z());

    return true;

}

void Sub::surface_run()
{
    float target_roll, target_pitch;
    float target_yaw_rate;

    // if not armed set throttle to zero and exit immediately
    if (!motors.armed() || !motors.get_interlock()) {
    	motors.output_min();
        motors.set_desired_spool_state(AP_Motors::DESIRED_SPIN_WHEN_ARMED);
        attitude_control.set_throttle_out_unstabilized(0,true,g.throttle_filt);
        return;
    }

    // Already at surface, hold depth at surface
    if(ap.at_surface)
    	set_mode(ALT_HOLD, MODE_REASON_SURFACE_COMPLETE);

    // 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->get_control_in(), channel_pitch->get_control_in(), target_roll, target_pitch, aparm.angle_max);

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

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

    // set target climb rate
	float cmb_rate = constrain_float(abs(g.land_speed), 1, pos_control.get_speed_up());

    // record desired climb rate for logging
    desired_climb_rate = cmb_rate;

    // update altitude target and call position controller
    pos_control.set_alt_target_from_climb_rate_ff(cmb_rate, G_Dt, true);
    pos_control.update_z_controller();

    // pilot has control for repositioning
    motors.set_forward(channel_forward->norm_input());
    motors.set_lateral(channel_lateral->norm_input());
}