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/**
* @file MulticopterLandDetector.cpp
* Land detection algorithm for multicopters
*
* @author Johan Jansen <jnsn.johan@gmail.com>
* @author Morten Lysgaard <morten@lysgaard.no>
*/
#include "MulticopterLandDetector.h"
#include <cmath>
#include <drivers/drv_hrt.h>
#include <mathlib/mathlib.h>
MulticopterLandDetector::MulticopterLandDetector() : LandDetector(),
_paramHandle(),
_params(),
_vehicleGlobalPositionSub(-1),
_waypointSub(-1),
_actuatorsSub(-1),
_armingSub(-1),
_parameterSub(-1),
_attitudeSub(-1),
_vehicleGlobalPosition({}),
_waypoint({}),
_actuators({}),
_arming({}),
_vehicleAttitude({}),
_landTimer(0)
{
_paramHandle.maxRotation = param_find("LNDMC_ROT_MAX");
_paramHandle.maxVelocity = param_find("LNDMC_XY_VEL_MAX");
_paramHandle.maxClimbRate = param_find("LNDMC_Z_VEL_MAX");
_paramHandle.maxThrottle = param_find("LNDMC_THR_MAX");
}
void MulticopterLandDetector::initialize()
{
// subscribe to position, attitude, arming and velocity changes
_vehicleGlobalPositionSub = orb_subscribe(ORB_ID(vehicle_global_position));
_attitudeSub = orb_subscribe(ORB_ID(vehicle_attitude));
_waypointSub = orb_subscribe(ORB_ID(position_setpoint_triplet));
_actuatorsSub = orb_subscribe(ORB_ID_VEHICLE_ATTITUDE_CONTROLS);
_armingSub = orb_subscribe(ORB_ID(actuator_armed));
_parameterSub = orb_subscribe(ORB_ID(parameter_update));
// download parameters
updateParameterCache(true);
}
void MulticopterLandDetector::updateSubscriptions()
{
orb_update(ORB_ID(vehicle_global_position), _vehicleGlobalPositionSub, &_vehicleGlobalPosition);
orb_update(ORB_ID(vehicle_attitude), _attitudeSub, &_vehicleAttitude);
orb_update(ORB_ID(position_setpoint_triplet), _waypointSub, &_waypoint);
orb_update(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, _actuatorsSub, &_actuators);
orb_update(ORB_ID(actuator_armed), _armingSub, &_arming);
}
bool MulticopterLandDetector::update()
{
// first poll for new data from our subscriptions
updateSubscriptions();
// only trigger flight conditions if we are armed
if (!_arming.armed) {
return true;
}
const uint64_t now = hrt_absolute_time();
// check if we are moving vertically
bool verticalMovement = fabsf(_vehicleGlobalPosition.vel_d) > _params.maxClimbRate;
// check if we are moving horizontally
bool horizontalMovement = sqrtf(_vehicleGlobalPosition.vel_n * _vehicleGlobalPosition.vel_n
+ _vehicleGlobalPosition.vel_e * _vehicleGlobalPosition.vel_e) > _params.maxVelocity;
// next look if all rotation angles are not moving
bool rotating = sqrtf(_vehicleAttitude.rollspeed*_vehicleAttitude.rollspeed +
_vehicleAttitude.pitchspeed*_vehicleAttitude.pitchspeed +
_vehicleAttitude.yawspeed*_vehicleAttitude.yawspeed) > _params.maxRotation;
// check if thrust output is minimal (about half of default)
bool minimalThrust = _actuators.control[3] <= _params.maxThrottle;
if (verticalMovement || rotating || !minimalThrust || horizontalMovement) {
// sensed movement, so reset the land detector
_landTimer = now;
return false;
}
return now - _landTimer > LAND_DETECTOR_TRIGGER_TIME;
}
void MulticopterLandDetector::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.maxClimbRate, &_params.maxClimbRate);
param_get(_paramHandle.maxVelocity, &_params.maxVelocity);
param_get(_paramHandle.maxRotation, &_params.maxRotation);
_params.maxRotation = math::radians(_params.maxRotation);
param_get(_paramHandle.maxThrottle, &_params.maxThrottle);
}
}