VtolLandDetector.cpp

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/**
 * @file VtolLandDetector.cpp
 * Land detection algorithm for VTOL
 *
 * @author Roman Bapst <bapstroma@gmail.com>
 * @author Julian Oes <julian@oes.ch>
 */

#include <drivers/drv_hrt.h>

#include "VtolLandDetector.h"

namespace land_detector
{

void VtolLandDetector::_update_topics()
{
    MulticopterLandDetector::_update_topics();
    _airspeed_sub.update(&_airspeed);
    _vehicle_status_sub.update(&_vehicle_status);
}

bool VtolLandDetector::_get_maybe_landed_state()
{
    // If in Fixed-wing mode, only trigger if disarmed
    if ((_vehicle_status.timestamp != 0) && _vehicle_status.vehicle_type == vehicle_status_s::VEHICLE_TYPE_FIXED_WING) {
        return !_actuator_armed.armed;
    }

    return MulticopterLandDetector::_get_maybe_landed_state();
}

bool VtolLandDetector::_get_landed_state()
{
    // If in Fixed-wing mode, only trigger if disarmed
    if ((_vehicle_status.timestamp != 0) && _vehicle_status.vehicle_type == vehicle_status_s::VEHICLE_TYPE_FIXED_WING) {
        return !_actuator_armed.armed;
    }

    // this is returned from the mutlicopter land detector
    bool landed = MulticopterLandDetector::_get_landed_state();

    // for vtol we additionally consider airspeed
    if (hrt_elapsed_time(&_airspeed.timestamp) < 500 * 1000 && _airspeed.confidence > 0.99f
        && PX4_ISFINITE(_airspeed.indicated_airspeed_m_s)) {

        _airspeed_filtered = 0.95f * _airspeed_filtered + 0.05f * _airspeed.indicated_airspeed_m_s;

    } else {
        // if airspeed does not update, set it to zero and rely on multicopter land detector
        _airspeed_filtered = 0.0f;
    }

    // only consider airspeed if we have been in air before to avoid false
    // detections in the case of wind on the ground
    if (_was_in_air && (_airspeed_filtered > _param_lndfw_airspd_max.get())) {
        landed = false;
    }

    _was_in_air = !landed;

    return landed;
}

} // namespace land_detector