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Diffstat (limited to 'src/modules/land_detector/FixedwingLandDetector.cpp')
| -rw-r--r-- | src/modules/land_detector/FixedwingLandDetector.cpp | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/src/modules/land_detector/FixedwingLandDetector.cpp b/src/modules/land_detector/FixedwingLandDetector.cpp new file mode 100644 index 000000000..8e5bcf7ba --- /dev/null +++ b/src/modules/land_detector/FixedwingLandDetector.cpp @@ -0,0 +1,125 @@ +/**************************************************************************** + * + * Copyright (c) 2013-2015 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 FixedwingLandDetector.cpp + * Land detection algorithm for fixedwings + * + * @author Johan Jansen <jnsn.johan@gmail.com> + */ + +#include "FixedwingLandDetector.h" + +#include <cmath> +#include <drivers/drv_hrt.h> + +FixedwingLandDetector::FixedwingLandDetector() : LandDetector(), + _paramHandle(), + _params(), + _vehicleLocalPositionSub(-1), + _vehicleLocalPosition({}), + _airspeedSub(-1), + _airspeed({}), + _parameterSub(-1), + _velocity_xy_filtered(0.0f), + _velocity_z_filtered(0.0f), + _airspeed_filtered(0.0f), + _landDetectTrigger(0) +{ + _paramHandle.maxVelocity = param_find("LNDFW_VEL_XY_MAX"); + _paramHandle.maxClimbRate = param_find("LNDFW_VEL_Z_MAX"); + _paramHandle.maxAirSpeed = param_find("LNDFW_AIRSPD_MAX"); +} + +void FixedwingLandDetector::initialize() +{ + // Subscribe to local position and airspeed data + _vehicleLocalPositionSub = orb_subscribe(ORB_ID(vehicle_local_position)); + _airspeedSub = orb_subscribe(ORB_ID(airspeed)); +} + +void FixedwingLandDetector::updateSubscriptions() +{ + orb_update(ORB_ID(vehicle_local_position), _vehicleLocalPositionSub, &_vehicleLocalPosition); + orb_update(ORB_ID(airspeed), _airspeedSub, &_airspeed); +} + +bool FixedwingLandDetector::update() +{ + // First poll for new data from our subscriptions + updateSubscriptions(); + + const uint64_t now = hrt_absolute_time(); + bool landDetected = false; + + // TODO: reset filtered values on arming? + _velocity_xy_filtered = 0.95f * _velocity_xy_filtered + 0.05f * sqrtf(_vehicleLocalPosition.vx * + _vehicleLocalPosition.vx + _vehicleLocalPosition.vy * _vehicleLocalPosition.vy); + _velocity_z_filtered = 0.95f * _velocity_z_filtered + 0.05f * fabsf(_vehicleLocalPosition.vz); + _airspeed_filtered = 0.95f * _airspeed_filtered + 0.05f * _airspeed.true_airspeed_m_s; + + // crude land detector for fixedwing + if (_velocity_xy_filtered < _params.maxVelocity + && _velocity_z_filtered < _params.maxClimbRate + && _airspeed_filtered < _params.maxAirSpeed) { + + // these conditions need to be stable for a period of time before we trust them + if (now > _landDetectTrigger) { + landDetected = true; + } + + } else { + // reset land detect trigger + _landDetectTrigger = now + LAND_DETECTOR_TRIGGER_TIME; + } + + return landDetected; +} + +void FixedwingLandDetector::updateParameterCache(const bool force) +{ + bool updated; + parameter_update_s paramUpdate; + + orb_check(_parameterSub, &updated); + + if (updated) { + orb_copy(ORB_ID(parameter_update), _parameterSub, ¶mUpdate); + } + + if (updated || force) { + param_get(_paramHandle.maxVelocity, &_params.maxVelocity); + param_get(_paramHandle.maxClimbRate, &_params.maxClimbRate); + param_get(_paramHandle.maxAirSpeed, &_params.maxAirSpeed); + } +} |