ardupilot/ArduCopter/control_auto.pde

/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-

/*
 * control_auto.pde - init and run calls for auto, guided, land and RTL flight modes
 */

// auto_init - initialise auto controller
static bool auto_init(bool ignore_checks)
{
    if ((GPS_ok() && g.command_total > 1) || ignore_checks) {
        // set target to current position
        wp_nav.init_loiter_target();
        // initialise auto_yaw_mode
        set_auto_yaw_mode(get_default_auto_yaw_mode(false));
        // clear the command queues. will be reloaded when "run_autopilot" calls "update_commands" function
        init_commands();
        return true;
    }else{
        return false;
    }
}

// auto_run - runs the auto controller
//      should be called at 100hz or more
//      relies on run_autopilot being called at 10hz which handles decision making and non-navigation related commands
static void auto_run()
{
    float target_yaw_rate = 0;

    // if not auto armed set throttle to zero and exit immediately
    if(!ap.auto_armed || !inertial_nav.position_ok()) {
        wp_nav.init_loiter_target();
        attitude_control.init_targets();
        attitude_control.set_throttle_out(0, false);
        return;
    }

    // process pilot's yaw input
    if (!failsafe.radio) {
        // get pilot's desired yaw rate
        target_yaw_rate = get_pilot_desired_yaw_rate(g.rc_4.control_in);
        if (target_yaw_rate != 0) {
            set_auto_yaw_mode(AUTO_YAW_HOLD);
        }
    }

    // run waypoint controller
    wp_nav.update_wpnav();

    // call z-axis position controller (wpnav should have already updated it's alt target)
    pos_control.update_z_controller();

    // call attitude controller
    if (auto_yaw_mode == AUTO_YAW_HOLD) {
        // roll & pitch from waypoint controller, yaw rate from pilot
        attitude_control.angleef_rp_rateef_y(wp_nav.get_roll(), wp_nav.get_pitch(), target_yaw_rate);
    }else{
        // roll, pitch from waypoint controller, yaw heading from auto_heading()
        attitude_control.angleef_rpy(wp_nav.get_roll(), wp_nav.get_pitch(), get_auto_heading());
    }

    // body-frame rate controller is run directly from 100hz loop

    // refetch angle targets for reporting
    const Vector3f angle_target = attitude_control.angle_ef_targets();
    control_roll = angle_target.x;
    control_pitch = angle_target.y;
    control_yaw = angle_target.z;
}

// get_default_auto_yaw_mode - returns auto_yaw_mode based on WP_YAW_BEHAVIOR parameter
// set rtl parameter to true if this is during an RTL
uint8_t get_default_auto_yaw_mode(bool rtl)
{
    switch (g.wp_yaw_behavior) {

        case WP_YAW_BEHAVIOR_LOOK_AT_NEXT_WP_EXCEPT_RTL:
            if (rtl) {
                return AUTO_YAW_HOLD;
            }else{
                return AUTO_YAW_LOOK_AT_NEXT_WP;
            }
            break;

        case WP_YAW_BEHAVIOR_LOOK_AHEAD:
            return AUTO_YAW_LOOK_AHEAD;
            break;

        case WP_YAW_BEHAVIOR_LOOK_AT_NEXT_WP:
        default:
            return AUTO_YAW_LOOK_AT_NEXT_WP;
            break;
    }
}

// set_auto_yaw_mode - sets the yaw mode for auto
void set_auto_yaw_mode(uint8_t yaw_mode)
{
    // return immediately if no change
    if (auto_yaw_mode == yaw_mode) {
        return;
    }
    auto_yaw_mode = yaw_mode;

    // perform initialisation
    switch (auto_yaw_mode) {

    case AUTO_YAW_LOOK_AT_NEXT_WP:
        // original_wp_bearing will be set by do_nav_wp or other nav command initialisatoin functions so no init required
        break;

    case AUTO_YAW_LOOK_AT_LOCATION:
        // point towards a location held in yaw_look_at_WP
        yaw_look_at_WP_bearing = ahrs.yaw_sensor;
        break;

    case AUTO_YAW_LOOK_AT_HEADING:
        // keep heading pointing in the direction held in yaw_look_at_heading with no pilot input allowed
        yaw_look_at_heading = ahrs.yaw_sensor;
        break;

    case AUTO_YAW_LOOK_AHEAD:
        // Commanded Yaw to automatically look ahead.
        yaw_look_ahead_bearing = ahrs.yaw_sensor;
        break;

    case AUTO_YAW_RESETTOARMEDYAW:
        // initial_armed_bearing will be set during arming so no init required
        break;
    }
}

// get_auto_heading - returns target heading depending upon auto_yaw_mode
// 100hz update rate
float get_auto_heading(void)
{
    switch(auto_yaw_mode) {

    case AUTO_YAW_LOOK_AT_LOCATION:
        // point towards a location held in yaw_look_at_WP
        return get_look_at_yaw();
        break;

    case AUTO_YAW_LOOK_AT_HEADING:
        // keep heading pointing in the direction held in yaw_look_at_heading with no pilot input allowed
        return yaw_look_at_heading;
        break;

    case AUTO_YAW_LOOK_AHEAD:
        // Commanded Yaw to automatically look ahead.
        return get_look_ahead_yaw();
        break;

    case AUTO_YAW_RESETTOARMEDYAW:
        // changes yaw to be same as when quad was armed
        control_yaw = initial_armed_bearing;
        break;

    case AUTO_YAW_LOOK_AT_NEXT_WP:
    default:
        // point towards next waypoint.
        // we don't use wp_bearing because we don't want the copter to turn too much during flight
        return original_wp_bearing;
        break;
    }
}

// guided_init - initialise guided controller
static bool guided_init(bool ignore_checks)
{
    if (GPS_ok() || ignore_checks) {
        return true;
    }else{
        return false;
    }
}

// guided_run - runs the guided controller
// should be called at 100hz or more
static void guided_run()
{
}

// land_init - initialise land controller
static bool land_init(bool ignore_checks)
{
    return true;
}

// land_run - runs the land controller
// should be called at 100hz or more
static void land_run()
{
    verify_land();
}

// rtl_init - initialise rtl controller
static bool rtl_init(bool ignore_checks)
{
    if (GPS_ok() || ignore_checks) {
        do_RTL();
        return true;
    }else{
        return false;
    }
}

// rtl_run - runs the return-to-launch controller
// should be called at 100hz or more
static void rtl_run()
{
    verify_RTL();
}