ardupilot/ArduPlane/mode_takeoff.cpp

#include "mode.h"
#include "Plane.h"

/*
  mode takeoff parameters
 */
const AP_Param::GroupInfo ModeTakeoff::var_info[] = {
    // @Param: ALT
    // @DisplayName: Takeoff mode altitude
    // @Description: This is the target altitude for TAKEOFF mode
    // @Range: 0 200
    // @Increment: 1
    // @Units: m
    // @User: Standard
    AP_GROUPINFO("ALT", 1, ModeTakeoff, target_alt, 50),

    // @Param: LVL_ALT
    // @DisplayName: Takeoff mode altitude level altitude
    // @Description: This is the altitude below which wings are held level for TAKEOFF mode
    // @Range: 0 50
    // @Increment: 1
    // @Units: m
    // @User: Standard
    AP_GROUPINFO("LVL_ALT", 2, ModeTakeoff, level_alt, 20),

    // @Param: LVL_PITCH
    // @DisplayName: Takeoff mode altitude initial pitch
    // @Description: This is the target pitch for the initial climb to TKOFF_LVL_ALT
    // @Range: 0 30
    // @Increment: 1
    // @Units: deg
    // @User: Standard
    AP_GROUPINFO("LVL_PITCH", 3, ModeTakeoff, level_pitch, 15),

    // @Param: DIST
    // @DisplayName: Takeoff mode distance
    // @Description: This is the distance from the takeoff location where the plane will loiter. The loiter point will be in the direction of takeoff (the direction the plane is facing when the motor starts)
    // @Range: 0 500
    // @Increment: 1
    // @Units: m
    // @User: Standard
    AP_GROUPINFO("DIST", 4, ModeTakeoff, target_dist, 200),
    
    // @Param: GND_PITCH
    // @DisplayName: Takeoff run pitch demand
    // @Description: Degrees of pitch angle demanded during the takeoff run before speed reaches TKOFF_ROTATE_SPD. For taildraggers set to 3-point ground pitch angle and use TKOFF_TDRAG_ELEV to prevent nose tipover. For nose-wheel steer aircraft set to the ground pitch angle and if a reduction in nose-wheel load is required as speed rises, use a positive offset in TKOFF_GND_PITCH of up to 5 degrees above the angle on ground, starting at the mesured pitch angle and incrementing in 1 degree steps whilst checking for premature rotation and takeoff with each increment. To increase nose-wheel load, use a negative TKOFF_TDRAG_ELEV and refer to notes on TKOFF_TDRAG_ELEV before making adjustments.
    // @Units: deg
    // @Range: -5.0 10.0
    // @Increment: 0.1
    // @User: Standard
    AP_GROUPINFO("GND_PITCH", 5, ModeTakeoff, ground_pitch, 5),

    AP_GROUPEND
};

ModeTakeoff::ModeTakeoff() :
    Mode()
{
    AP_Param::setup_object_defaults(this, var_info);
}

bool ModeTakeoff::_enter()
{
    takeoff_started = false;

    return true;
}

void ModeTakeoff::update()
{
    if (!takeoff_started) {
        // see if we will skip takeoff as already flying
        if (plane.is_flying() && (millis() - plane.started_flying_ms > 10000U) && ahrs.groundspeed() > 3) {
            gcs().send_text(MAV_SEVERITY_INFO, "Takeoff skipped - circling");
            plane.prev_WP_loc = plane.current_loc;
            plane.next_WP_loc = plane.current_loc;
            takeoff_started = true;
            plane.set_flight_stage(AP_FixedWing::FlightStage::NORMAL);
        }
    }

    if (!takeoff_started) {
        // setup target location 1.5 times loiter radius from the
        // takeoff point, at a height of TKOFF_ALT
        const float dist = target_dist;
        const float alt = target_alt;
        const float direction = degrees(ahrs.yaw);

        start_loc = plane.current_loc;
        plane.prev_WP_loc = plane.current_loc;
        plane.next_WP_loc = plane.current_loc;
        plane.next_WP_loc.alt += alt*100.0;
        plane.next_WP_loc.offset_bearing(direction, dist);

        plane.crash_state.is_crashed = false;

        plane.auto_state.takeoff_pitch_cd = level_pitch * 100;

        plane.set_flight_stage(AP_FixedWing::FlightStage::TAKEOFF);

        if (!plane.throttle_suppressed) {
            gcs().send_text(MAV_SEVERITY_INFO, "Takeoff to %.0fm at %.1fm to %.1f deg",
                            alt, dist, direction);
            takeoff_started = true;
        }
    }

    // we finish the initial level takeoff if we climb past
    // TKOFF_LVL_ALT or we pass the target location. The check for
    // target location prevents us flying forever if we can't climb
    if (plane.flight_stage == AP_FixedWing::FlightStage::TAKEOFF &&
        (plane.current_loc.alt - start_loc.alt >= level_alt*100 ||
         start_loc.get_distance(plane.current_loc) >= target_dist)) {
        // reached level alt, re-calculate bearing to cope with systems with no compass
        // or with poor initial compass
        float direction = start_loc.get_bearing_to(plane.current_loc) * 0.01;
        float dist_done = start_loc.get_distance(plane.current_loc);
        const float dist = target_dist;

        plane.next_WP_loc = plane.current_loc;
        plane.next_WP_loc.offset_bearing(direction, MAX(dist-dist_done, 0));
        plane.next_WP_loc.alt = start_loc.alt + target_alt*100.0;

        plane.set_flight_stage(AP_FixedWing::FlightStage::NORMAL);
        
#if AP_FENCE_ENABLED
        plane.fence.auto_enable_fence_after_takeoff();
#endif
    }

    if (plane.flight_stage == AP_FixedWing::FlightStage::TAKEOFF) {
        SRV_Channels::set_output_scaled(SRV_Channel::k_throttle, 100.0);
        plane.takeoff_calc_roll();
        plane.takeoff_calc_pitch();
    } else {
        plane.calc_nav_roll();
        plane.calc_nav_pitch();
        plane.calc_throttle();
    }
}

void ModeTakeoff::navigate()
{
    // Zero indicates to use WP_LOITER_RAD
    plane.update_loiter(0);
}