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/**
* @file MulticopterLandDetector.cpp
* Land detection algorithm
*
* @author Johan Jansen <jnsn.johan@gmail.com>
* @author Morten Lysgaard <morten@lysgaard.no>
*/
#include "MulticopterLandDetector.h"
#include <cmath>
#include <drivers/drv_hrt.h>
MulticopterLandDetector::MulticopterLandDetector() :
_vehicleGlobalPositionSub(-1),
_sensorsCombinedSub(-1),
_waypointSub(-1),
_actuatorsSub(-1),
_armingSub(-1),
_vehicleGlobalPosition({}),
_sensors({}),
_waypoint({}),
_actuators({}),
_arming({}),
_landTimer(0)
{
//ctor
}
void MulticopterLandDetector::initialize()
{
//Subscribe to position, attitude, arming and velocity changes
_vehicleGlobalPositionSub = orb_subscribe(ORB_ID(vehicle_global_position));
_sensorsCombinedSub = orb_subscribe(ORB_ID(sensor_combined));
_waypointSub = orb_subscribe(ORB_ID(position_setpoint_triplet));
_actuatorsSub = orb_subscribe(ORB_ID_VEHICLE_ATTITUDE_CONTROLS);
_armingSub = orb_subscribe(ORB_ID(actuator_armed));
}
void MulticopterLandDetector::updateSubscriptions()
{
orb_update(ORB_ID(vehicle_global_position), _vehicleGlobalPositionSub, &_vehicleGlobalPosition);
orb_update(ORB_ID(sensor_combined), _sensorsCombinedSub, &_sensors);
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();
const uint64_t now = hrt_absolute_time();
//only detect landing if the autopilot is actively trying to land
if (!_waypoint.current.valid || _waypoint.current.type != SETPOINT_TYPE_LAND) {
_landTimer = now;
} else {
//Check if we are moving vertically
bool verticalMovement = fabsf(_vehicleGlobalPosition.vel_d) > MC_LAND_DETECTOR_CLIMBRATE_MAX;
//Check if we are moving horizontally
bool horizontalMovement = sqrtf(_vehicleGlobalPosition.vel_n * _vehicleGlobalPosition.vel_n
+ _vehicleGlobalPosition.vel_e * _vehicleGlobalPosition.vel_e) > MC_LAND_DETECTOR_VELOCITY_MAX;
//Next look if all rotation angles are not moving
bool rotating = sqrtf(_sensors.gyro_rad_s[0] * _sensors.gyro_rad_s[0] +
_sensors.gyro_rad_s[1] * _sensors.gyro_rad_s[1] +
_sensors.gyro_rad_s[2] * _sensors.gyro_rad_s[2]) > MC_LAND_DETECTOR_ROTATION_MAX;
//Check if thrust output is minimal (about half of default)
bool minimalThrust = _arming.armed && _actuators.control[3] <= MC_LAND_DETECTOR_THRUST_MAX;
if (verticalMovement || rotating || !minimalThrust || horizontalMovement) {
//Sensed movement, so reset the land detector
_landTimer = now;
}
}
return now - _landTimer > MC_LAND_DETECTOR_TRIGGER_TIME;
}