1 files changed, 212 insertions, 0 deletions
diff --git a/src/modules/mc_land_detector/MulticopterLandDetector.cpp b/src/modules/mc_land_detector/MulticopterLandDetector.cpp
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+++ b/src/modules/mc_land_detector/MulticopterLandDetector.cpp
@@ -0,0 +1,212 @@
+/****************************************************************************
+ *
+ *   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 MultiCopterLandDetector.cpp
+ * Land detection algorithm for multicopters
+ *
+ * @author Johan Jansen <jnsn.johan@gmail.com>
+ * @author Morten Lysgaard <morten@lysgaard.no>
+ */
+
+#include "MulticopterLandDetector.h"
+
+#include <stdio.h>
+#include <cmath>
+#include <drivers/drv_hrt.h>
+#include <unistd.h>                 //usleep
+
+MulticopterLandDetector::MulticopterLandDetector() :
+    _landDetectedPub(-1),
+    _landDetected({0,false}),
+    
+    _vehicleGlobalPositionSub(-1),
+    _sensorsCombinedSub(-1),
+    _waypointSub(-1),
+    _actuatorsSub(-1),
+    _armingSub(-1),
+
+    _vehicleGlobalPosition({}),
+    _sensors({}),
+    _waypoint({}),
+    _actuators({}),
+    _arming({}),
+
+    _taskShouldExit(false),
+    _taskIsRunning(false),
+    _landTimer(0)
+{
+    //Advertise the first land detected uORB
+    _landDetected.timestamp = hrt_absolute_time();
+    _landDetected.landed = false;
+    _landDetectedPub = orb_advertise(ORB_ID(vehicle_land_detected), &_landDetected);
+}
+
+MulticopterLandDetector::~MulticopterLandDetector()
+{
+    _taskShouldExit = true;
+    close(_landDetectedPub);
+}
+
+/**
+* @brief Convinience function for polling uORB subscriptions
+* @return true if there was new data and it was successfully copied
+**/
+static bool orb_update(const struct orb_metadata *meta, int handle, void *buffer)
+{
+    bool newData = false;
+
+    //Check if there is new data to grab
+    if(orb_check(handle, &newData) != OK) {
+        return false;
+    }
+
+    if(!newData) {
+        return false;
+    }
+
+    if(orb_copy(meta, handle, buffer) != OK) {
+        return false;
+    }
+
+    return true;
+}
+
+void MulticopterLandDetector::shutdown()
+{
+    _taskShouldExit = true;
+}
+
+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);
+}
+
+void MulticopterLandDetector::landDetectorLoop()
+{
+    //This should never happen!
+    if(_taskIsRunning) return;
+
+    //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));
+
+    //Begin task
+    _taskIsRunning = true;
+    _taskShouldExit = false;
+    while (!_taskShouldExit) {
+
+        //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 {
+            /*
+            static int debugcnt = 0;
+            if(debugcnt++ > 12) {
+                debugcnt = 0;
+                mavlink_log_critical(_mavlinkFd, "T: %.4f   R: %.4f", (double)_actuators.control[3], 
+                    sqrt( _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]));
+            }
+            */
+
+            //Check if we are moving vertically
+            bool verticalMovement = fabsf(_vehicleGlobalPosition.vel_d) > MC_LAND_DETECTOR_CLIMBRATE_MAX;
+
+            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;
+            }
+
+        }
+
+        // if we have detected a landing for 2 continious seconds
+        if(now-_landTimer > 2000000) {
+            if(!_landDetected.landed)
+            {
+                _landDetected.timestamp = now;
+                _landDetected.landed = true;
+
+                /* publish the land detected broadcast */
+                orb_publish(ORB_ID(vehicle_land_detected), _landDetectedPub, &_landDetected);
+            }
+        }
+        else {
+            // if we currently think we have landed, but the latest data says we are flying
+            if(_landDetected.landed)
+            {
+                _landDetected.timestamp = now;
+                _landDetected.landed = false;
+
+                /* publish the land detected broadcast */
+                orb_publish(ORB_ID(vehicle_land_detected), _landDetectedPub, &_landDetected);
+            }
+        }
+
+        //Limit loop rate
+        usleep(1000000 / MC_LAND_DETECTOR_UPDATE_RATE);
+    }
+
+    _taskIsRunning = false;
+    _exit(0);
+}
+
+bool MulticopterLandDetector::isRunning() const
+{
+    return _taskIsRunning;
+}