Add a Takeoff class to handle multicopter takeoff

In a deterministic way with clear states to go through.

src/modules/mc_pos_control/CMakeLists.txt

@@ -30,6 +30,9 @@
 # POSSIBILITY OF SUCH DAMAGE.
 #
 ############################################################################
+
+add_subdirectory(Takeoff)
+
 px4_add_module(
 	MODULE modules__mc_pos_control
 	MAIN mc_pos_control
@@ -46,4 +49,5 @@ px4_add_module(
 		ecl_geo
 		WeatherVane
 		CollisionPrevention
+		Takeoff
 	)

src/modules/mc_pos_control/Takeoff/CMakeLists.txt

@@ -0,0 +1,42 @@
+############################################################################
+#
+#   Copyright (c) 2019 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(Takeoff
+	Takeoff.cpp
+)
+target_include_directories(Takeoff
+	PUBLIC
+	${CMAKE_CURRENT_SOURCE_DIR}
+)
+
+px4_add_gtest(SRC TakeoffTest.cpp LINKLIBS Takeoff)

src/modules/mc_pos_control/Takeoff/Takeoff.cpp

@@ -0,0 +1,121 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2019 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 Takeoff.cpp
+ */
+
+#include "Takeoff.hpp"
+#include <float.h>
+
+void Takeoff::updateTakeoffState(const bool armed, const bool landed, const bool want_takeoff,
+				 const float takeoff_desired_thrust, const bool skip_takeoff)
+{
+	_spoolup_time_hysteresis.set_state_and_update(armed);
+
+	switch (_takeoff_state) {
+	case TakeoffState::disarmed:
+		if (armed) {
+			_takeoff_state = TakeoffState::spoolup;
+
+		} else {
+			break;
+		}
+
+	case TakeoffState::spoolup:
+		if (_spoolup_time_hysteresis.get_state()) {
+			_takeoff_state = TakeoffState::ready_for_takeoff;
+
+		} else {
+			break;
+		}
+
+	case TakeoffState::ready_for_takeoff:
+		if (want_takeoff) {
+			_takeoff_state = TakeoffState::rampup;
+			_takeoff_ramp_thrust = 0.0f;
+
+		} else {
+			break;
+		}
+
+	case TakeoffState::rampup:
+		if (_takeoff_ramp_thrust <= takeoff_desired_thrust) {
+			_takeoff_state = TakeoffState::flight;
+
+		} else {
+			break;
+		}
+
+	case TakeoffState::flight:
+		if (landed) {
+			_takeoff_state = TakeoffState::ready_for_takeoff;
+		}
+
+		break;
+
+	default:
+		break;
+	}
+
+	if (armed && skip_takeoff) {
+		_takeoff_state = TakeoffState::flight;
+	}
+
+	// TODO: need to consider free fall here
+	if (!armed) {
+		_takeoff_state = TakeoffState::disarmed;
+	}
+}
+
+float Takeoff::updateThrustRamp(const float takeoff_desired_thrust, const float dt)
+{
+	if (_takeoff_state < TakeoffState::rampup) {
+		return 0.f;
+	}
+
+	if (_takeoff_state == TakeoffState::rampup) {
+		if (_takeoff_ramp_time > FLT_EPSILON) {
+			_takeoff_ramp_thrust += takeoff_desired_thrust * dt / _takeoff_ramp_time;
+
+		} else {
+			_takeoff_ramp_thrust = takeoff_desired_thrust;
+		}
+
+		if (_takeoff_ramp_thrust > takeoff_desired_thrust) {
+			return _takeoff_ramp_thrust;
+		}
+	}
+
+	return takeoff_desired_thrust;
+}

src/modules/mc_pos_control/Takeoff/Takeoff.hpp

@@ -0,0 +1,83 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2019 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 Takeoff.hpp
+ *
+ * A class handling all takeoff states and a smooth ramp up of the motors.
+ */
+
+#pragma once
+
+#include <systemlib/hysteresis/hysteresis.h>
+#include <drivers/drv_hrt.h>
+
+using namespace time_literals;
+
+enum class TakeoffState {
+	disarmed = 0,
+	spoolup,
+	ready_for_takeoff,
+	rampup,
+	flight
+};
+
+class Takeoff
+{
+public:
+
+	Takeoff() = default;
+	~Takeoff() = default;
+
+	/**
+	 * Update the state for the takeoff.
+	 * @param setpoint a vehicle_local_position_setpoint_s structure
+	 * @return true if setpoint has updated correctly
+	 */
+	void updateTakeoffState(const bool armed, const bool landed, const bool want_takeoff,
+				const float takeoff_desired_thrust, const bool skip_takeoff);
+	float updateThrustRamp(const float dt, const float takeoff_desired_thrust);
+
+	void setTakeoffRampTime(const float seconds) { _takeoff_ramp_time = seconds; }
+	void setSpoolupTime(const float seconds) { _spoolup_time_hysteresis.set_hysteresis_time_from(false, (hrt_abstime)(seconds * (float)1_s)); }
+	TakeoffState getTakeoffState() { return _takeoff_state; }
+
+	// TODO: make this private as soon as tasks also run while disarmed and updateTakeoffState gets called all the time
+	systemlib::Hysteresis _spoolup_time_hysteresis{false}; /**< becomes true MPC_SPOOLUP_TIME seconds after the vehicle was armed */
+
+private:
+	TakeoffState _takeoff_state = TakeoffState::disarmed;
+
+	float _takeoff_ramp_time = 0.f;
+	float _takeoff_ramp_thrust = 0.f;
+};

src/modules/mc_pos_control/Takeoff/TakeoffTest.cpp

@@ -0,0 +1,49 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2019 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.
+ *
+ ****************************************************************************/
+
+#include <gtest/gtest.h>
+#include <Takeoff.hpp>
+
+TEST(TakeoffTest, Initialization)
+{
+	Takeoff takeoff;
+	EXPECT_EQ(takeoff.getTakeoffState(), TakeoffState::disarmed);
+}
+
+// TEST(TakeoffTest, Ramp)
+// {
+// 	Takeoff takeoff;
+// 	takeoff.updateTakeoffState(true, false, true, 1.f, false);
+// 	takeoff.updateThrustRamp(1.f, 0.1f);
+// 	EXPECT_EQ(takeoff.getTakeoffState(), TakeoffState::disarmed);
+// }