FlightTaskDescend.cpp

Go to the documentation of this file.

/****************************************************************************
 *
 *   Copyright (c) 2019 PX4 Development Team. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name PX4 nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/
/**
 * @file FlightTaskDescend.cpp
 */

#include "FlightTaskDescend.hpp"

bool FlightTaskDescend::activate(vehicle_local_position_setpoint_s last_setpoint)
{
    bool ret = FlightTask::activate(last_setpoint);
    // stay level to minimize horizontal drift
    _thrust_setpoint = matrix::Vector3f(0.0f, 0.0f, NAN);
    // keep heading
    _yaw_setpoint = _yaw;
    return ret;
}

bool FlightTaskDescend::update()
{
    if (PX4_ISFINITE(_velocity(2))) {
        // land with landspeed
        _velocity_setpoint(2) = _param_mpc_land_speed.get();
        _thrust_setpoint(2) = NAN;

    } else {
        // descend with constant thrust (crash landing)
        _velocity_setpoint(2) = NAN;
        _thrust_setpoint(2) = -_param_mpc_thr_hover.get() * 0.7f;
    }

    return true;
}