From 515d81b8d65dbab25aadf7543893621c918c9a82 Mon Sep 17 00:00:00 2001
From: Lorenz Meier <lm@inf.ethz.ch>
Date: Sat, 14 Nov 2015 15:13:56 +0100
Subject: [PATCH] Land detector: Move back to more agile raw airspeed

---
 src/modules/land_detector/FixedwingLandDetector.cpp | 9 +++++++--
 src/modules/land_detector/FixedwingLandDetector.h   | 5 ++++-
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/modules/land_detector/FixedwingLandDetector.cpp b/src/modules/land_detector/FixedwingLandDetector.cpp
index 7614ccd3d1..31c1195281 100644
--- a/src/modules/land_detector/FixedwingLandDetector.cpp
+++ b/src/modules/land_detector/FixedwingLandDetector.cpp
@@ -50,11 +50,13 @@ FixedwingLandDetector::FixedwingLandDetector() : LandDetector(),
 	_paramHandle(),
 	_params(),
 	_controlStateSub(-1),
-	_controlState{},
 	_vehicleStatusSub(-1),
 	_armingSub(-1),
+	_airspeedSub(-1),
+	_controlState{},
 	_vehicleStatus{},
 	_arming{},
+	_airspeed{},
 	_parameterSub(-1),
 	_velocity_xy_filtered(0.0f),
 	_velocity_z_filtered(0.0f),
@@ -76,6 +78,7 @@ void FixedwingLandDetector::initialize()
 	_controlStateSub = orb_subscribe(ORB_ID(control_state));
 	_vehicleStatusSub = orb_subscribe(ORB_ID(vehicle_status));
 	_armingSub = orb_subscribe(ORB_ID(actuator_armed));
+	_airspeedSub = orb_subscribe(ORB_ID(airspeed));
 
 	updateParameterCache(true);
 }
@@ -85,6 +88,7 @@ void FixedwingLandDetector::updateSubscriptions()
 	orb_update(ORB_ID(control_state), _controlStateSub, &_controlState);
 	orb_update(ORB_ID(vehicle_status), _vehicleStatusSub, &_vehicleStatus);
 	orb_update(ORB_ID(actuator_armed), _armingSub, &_arming);
+	orb_update(ORB_ID(airspeed), _airspeedSub, &_airspeed);
 }
 
 bool FixedwingLandDetector::update()
@@ -117,7 +121,7 @@ bool FixedwingLandDetector::update()
 			_velocity_z_filtered = val;
 		}
 
-		_airspeed_filtered = 0.95f * _airspeed_filtered + 0.05f * _controlState.airspeed;
+		_airspeed_filtered = 0.95f * _airspeed_filtered + 0.05f * _airspeed.true_airspeed_m_s;
 
 		if (_lastTime != 0) {
 			/* a leaking integrator prevents biases from building up, but
@@ -125,6 +129,7 @@ bool FixedwingLandDetector::update()
 			 */
 			_accel_x_integral = _accel_x_integral * 0.8f + _controlState.horz_acc_mag * 0.18f;
 		}
+
 	}
 
 	// crude land detector for fixedwing
diff --git a/src/modules/land_detector/FixedwingLandDetector.h b/src/modules/land_detector/FixedwingLandDetector.h
index cce99cb9fc..32179c8698 100644
--- a/src/modules/land_detector/FixedwingLandDetector.h
+++ b/src/modules/land_detector/FixedwingLandDetector.h
@@ -46,6 +46,7 @@
 #include <uORB/topics/actuator_armed.h>
 #include <uORB/topics/parameter_update.h>
 #include <uORB/topics/vehicle_status.h>
+#include <uORB/topics/airspeed.h>
 #include <systemlib/param/param.h>
 
 class FixedwingLandDetector : public LandDetector
@@ -94,11 +95,13 @@ private:
 
 private:
 	int					_controlStateSub;	/**< notification of local position */
-	struct control_state_s			_controlState;		/**< the result from local position subscription */
 	int					_vehicleStatusSub;
 	int					_armingSub;
+	int					_airspeedSub;
+	struct control_state_s			_controlState;		/**< the result from local position subscription */
 	struct vehicle_status_s 		_vehicleStatus;
 	struct actuator_armed_s			_arming;
+	struct airspeed_s			_airspeed;
 	int 					_parameterSub;
 
 	float _velocity_xy_filtered;