FlightTaskFailure: will hover if position available, will land if velocity valid and

will land with 0.3 of hover thurst if position nor velocity is valid

src/lib/FlightTasks/CMakeLists.txt

@@ -60,6 +60,7 @@ list(APPEND flight_tasks_all
 	AutoLine
 	AutoFollowMe
 	Offboard
+	Failsafe
 	${flight_tasks_to_add}
 )
 

src/lib/FlightTasks/tasks/Failsafe/CMakeLists.txt

@@ -0,0 +1,39 @@
+############################################################################
+#
+#   Copyright (c) 2018 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.
+#
+############################################################################
+
+px4_add_library(FlightTaskFailsafe
+	FlightTaskFailsafe.cpp
+)
+
+target_link_libraries(FlightTaskFailsafe PUBLIC FlightTask)
+target_include_directories(FlightTaskFailsafe PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

src/lib/FlightTasks/tasks/Failsafe/FlightTaskFailsafe.cpp

@@ -0,0 +1,72 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2018 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 FlightTaskFailsafe.cpp
+ */
+
+#include "FlightTaskFailsafe.hpp"
+
+bool FlightTaskFailsafe::activate()
+{
+	bool ret = FlightTask::activate();
+	_position_setpoint = _position;
+	_velocity_setpoint *= 0.0f;
+	_thrust_setpoint = matrix::Vector3f(0.0f, 0.0f, -MPC_THR_HOVER.get() * 0.5f);
+	_yaw_setpoint = _yaw;
+	_yawspeed_setpoint = 0.0f;
+	return ret;
+}
+
+bool FlightTaskFailsafe::update()
+{
+	if (PX4_ISFINITE(_position(0)) && PX4_ISFINITE(_position(1))) {
+		_velocity_setpoint(0) = _velocity_setpoint(1) = 0.0f;
+		_thrust_setpoint(0) = _thrust_setpoint(1) = 0.0f;
+
+	} else if (PX4_ISFINITE(_velocity(0)) && PX4_ISFINITE(_velocity(1))) {
+		_position_setpoint(0) = _position_setpoint(1) = NAN;
+		_thrust_setpoint(0) = _thrust_setpoint(1) = NAN;
+	}
+
+	if (PX4_ISFINITE(_position(2))) {
+		_velocity_setpoint(2) = 0.0f;
+		_thrust_setpoint(2) = NAN;
+
+	} else if (PX4_ISFINITE(_velocity(2))) {
+		_position_setpoint(2) = NAN;
+		_thrust_setpoint(2) = NAN;
+	}
+
+	return true;
+
+}

src/lib/FlightTasks/tasks/Failsafe/FlightTaskFailsafe.hpp

@@ -0,0 +1,57 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2018 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 FlightTaskFailsafe.hpp
+ *
+ */
+
+#pragma once
+
+#include "FlightTask.hpp"
+
+class FlightTaskFailsafe : public FlightTask
+{
+public:
+	FlightTaskFailsafe() = default;
+
+	virtual ~FlightTaskFailsafe() = default;
+	bool update() override;
+	bool activate() override;
+
+private:
+	DEFINE_PARAMETERS_CUSTOM_PARENT(FlightTask,
+					(ParamFloat<px4::params::MPC_LAND_SPEED>) MPC_LAND_SPEED,
+					(ParamFloat<px4::params::MPC_THR_HOVER>) MPC_THR_HOVER /**< throttle value at which vehicle is at hover equilibrium */
+				       )
+};