Moved multirotor controllers

15 files changed, 2278 insertions, 0 deletions

diff --git a/src/modules/multirotor_att_control/module.mk b/src/modules/multirotor_att_control/module.mk
new file mode 100755
index 000000000..2fd52c162
--- /dev/null
+++ b/src/modules/multirotor_att_control/module.mk
@@ -0,0 +1,42 @@
+############################################################################
+#
+#   Copyright (c) 2012, 2013 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.
+#
+############################################################################
+
+#
+# Makefile to build the multirotor attitude controller
+#
+
+MODULE_COMMAND	= multirotor_att_control
+
+SRCS		= multirotor_att_control_main.c \
+		  multirotor_attitude_control.c \
+		  multirotor_rate_control.c
diff --git a/src/modules/multirotor_att_control/multirotor_att_control_main.c b/src/modules/multirotor_att_control/multirotor_att_control_main.c
new file mode 100644
index 000000000..d94c0a69c
--- /dev/null
+++ b/src/modules/multirotor_att_control/multirotor_att_control_main.c
@@ -0,0 +1,485 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+ *   Author: Lorenz Meier <lm@inf.ethz.ch>
+ *
+ * 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 multirotor_att_control_main.c
+ *
+ * Implementation of multirotor attitude control main loop.
+ *
+ * @author Lorenz Meier <lm@inf.ethz.ch>
+ */
+
+#include <nuttx/config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <debug.h>
+#include <getopt.h>
+#include <time.h>
+#include <math.h>
+#include <poll.h>
+#include <sys/prctl.h>
+#include <drivers/drv_hrt.h>
+#include <uORB/uORB.h>
+#include <drivers/drv_gyro.h>
+#include <uORB/topics/vehicle_status.h>
+#include <uORB/topics/vehicle_attitude.h>
+#include <uORB/topics/vehicle_attitude_setpoint.h>
+#include <uORB/topics/manual_control_setpoint.h>
+#include <uORB/topics/offboard_control_setpoint.h>
+#include <uORB/topics/vehicle_rates_setpoint.h>
+#include <uORB/topics/sensor_combined.h>
+#include <uORB/topics/actuator_controls.h>
+#include <uORB/topics/parameter_update.h>
+
+#include <systemlib/perf_counter.h>
+#include <systemlib/systemlib.h>
+#include <systemlib/param/param.h>
+
+#include "multirotor_attitude_control.h"
+#include "multirotor_rate_control.h"
+
+PARAM_DEFINE_FLOAT(MC_RCLOSS_THR, 0.0f); // This defines the throttle when the RC signal is lost.
+
+__EXPORT int multirotor_att_control_main(int argc, char *argv[]);
+
+static bool thread_should_exit;
+static int mc_task;
+static bool motor_test_mode = false;
+
+static orb_advert_t actuator_pub;
+
+static struct vehicle_status_s state;
+
+static int
+mc_thread_main(int argc, char *argv[])
+{
+	/* declare and safely initialize all structs */
+	memset(&state, 0, sizeof(state));
+	struct vehicle_attitude_s att;
+	memset(&att, 0, sizeof(att));
+	struct vehicle_attitude_setpoint_s att_sp;
+	memset(&att_sp, 0, sizeof(att_sp));
+	struct manual_control_setpoint_s manual;
+	memset(&manual, 0, sizeof(manual));
+	struct sensor_combined_s raw;
+	memset(&raw, 0, sizeof(raw));
+	struct offboard_control_setpoint_s offboard_sp;
+	memset(&offboard_sp, 0, sizeof(offboard_sp));
+	struct vehicle_rates_setpoint_s rates_sp;
+	memset(&rates_sp, 0, sizeof(rates_sp));
+
+	struct actuator_controls_s actuators;
+	memset(&actuators, 0, sizeof(actuators));
+
+	/* subscribe to attitude, motor setpoints and system state */
+	int att_sub = orb_subscribe(ORB_ID(vehicle_attitude));
+	int param_sub = orb_subscribe(ORB_ID(parameter_update));
+	int att_setpoint_sub = orb_subscribe(ORB_ID(vehicle_attitude_setpoint));
+	int setpoint_sub = orb_subscribe(ORB_ID(offboard_control_setpoint));
+	int state_sub = orb_subscribe(ORB_ID(vehicle_status));
+	int manual_sub = orb_subscribe(ORB_ID(manual_control_setpoint));
+	int sensor_sub = orb_subscribe(ORB_ID(sensor_combined));
+
+	/*
+	 * Do not rate-limit the loop to prevent aliasing
+	 * if rate-limiting would be desired later, the line below would
+	 * enable it.
+	 *
+	 * rate-limit the attitude subscription to 200Hz to pace our loop
+	 * orb_set_interval(att_sub, 5);
+	 */
+	struct pollfd fds[2] = {
+		{ .fd = att_sub, .events = POLLIN },
+		{ .fd = param_sub, .events = POLLIN }
+	};
+
+	/* publish actuator controls */
+	for (unsigned i = 0; i < NUM_ACTUATOR_CONTROLS; i++) {
+		actuators.control[i] = 0.0f;
+	}
+
+	actuator_pub = orb_advertise(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, &actuators);
+	orb_advert_t att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &att_sp);
+	orb_advert_t rates_sp_pub = orb_advertise(ORB_ID(vehicle_rates_setpoint), &rates_sp);
+	int rates_sp_sub = orb_subscribe(ORB_ID(vehicle_rates_setpoint));
+
+	/* register the perf counter */
+	perf_counter_t mc_loop_perf = perf_alloc(PC_ELAPSED, "multirotor_att_control_runtime");
+	perf_counter_t mc_interval_perf = perf_alloc(PC_INTERVAL, "multirotor_att_control_interval");
+	perf_counter_t mc_err_perf = perf_alloc(PC_COUNT, "multirotor_att_control_err");
+
+	/* welcome user */
+	printf("[multirotor_att_control] starting\n");
+
+	/* store last control mode to detect mode switches */
+	bool flag_control_manual_enabled = false;
+	bool flag_control_attitude_enabled = false;
+	bool flag_system_armed = false;
+
+	/* store if yaw position or yaw speed has been changed */
+	bool control_yaw_position = true;
+
+	/* store if we stopped a yaw movement */
+	bool first_time_after_yaw_speed_control = true;
+
+	/* prepare the handle for the failsafe throttle */
+	param_t failsafe_throttle_handle = param_find("MC_RCLOSS_THR");
+	float failsafe_throttle = 0.0f;
+
+
+	while (!thread_should_exit) {
+
+		/* wait for a sensor update, check for exit condition every 500 ms */
+		int ret = poll(fds, 2, 500);
+
+		if (ret < 0) {
+			/* poll error, count it in perf */
+			perf_count(mc_err_perf);
+
+		} else if (ret == 0) {
+			/* no return value, ignore */
+		} else {
+
+			/* only update parameters if they changed */
+			if (fds[1].revents & POLLIN) {
+				/* read from param to clear updated flag */
+				struct parameter_update_s update;
+				orb_copy(ORB_ID(parameter_update), param_sub, &update);
+
+				/* update parameters */
+				// XXX no params here yet
+			}
+
+			/* only run controller if attitude changed */
+			if (fds[0].revents & POLLIN) {
+
+				perf_begin(mc_loop_perf);
+
+				/* get a local copy of system state */
+				bool updated;
+				orb_check(state_sub, &updated);
+
+				if (updated) {
+					orb_copy(ORB_ID(vehicle_status), state_sub, &state);
+				}
+
+				/* get a local copy of manual setpoint */
+				orb_copy(ORB_ID(manual_control_setpoint), manual_sub, &manual);
+				/* get a local copy of attitude */
+				orb_copy(ORB_ID(vehicle_attitude), att_sub, &att);
+				/* get a local copy of attitude setpoint */
+				orb_copy(ORB_ID(vehicle_attitude_setpoint), att_setpoint_sub, &att_sp);
+				/* get a local copy of rates setpoint */
+				orb_check(setpoint_sub, &updated);
+
+				if (updated) {
+					orb_copy(ORB_ID(offboard_control_setpoint), setpoint_sub, &offboard_sp);
+				}
+
+				/* get a local copy of the current sensor values */
+				orb_copy(ORB_ID(sensor_combined), sensor_sub, &raw);
+
+
+				/** STEP 1: Define which input is the dominating control input */
+				if (state.flag_control_offboard_enabled) {
+					/* offboard inputs */
+					if (offboard_sp.mode == OFFBOARD_CONTROL_MODE_DIRECT_RATES) {
+						rates_sp.roll = offboard_sp.p1;
+						rates_sp.pitch = offboard_sp.p2;
+						rates_sp.yaw = offboard_sp.p3;
+						rates_sp.thrust = offboard_sp.p4;
+//						printf("thrust_rate=%8.4f\n",offboard_sp.p4);
+						rates_sp.timestamp = hrt_absolute_time();
+						orb_publish(ORB_ID(vehicle_rates_setpoint), rates_sp_pub, &rates_sp);
+
+					} else if (offboard_sp.mode == OFFBOARD_CONTROL_MODE_DIRECT_ATTITUDE) {
+						att_sp.roll_body = offboard_sp.p1;
+						att_sp.pitch_body = offboard_sp.p2;
+						att_sp.yaw_body = offboard_sp.p3;
+						att_sp.thrust = offboard_sp.p4;
+//						printf("thrust_att=%8.4f\n",offboard_sp.p4);
+						att_sp.timestamp = hrt_absolute_time();
+						/* STEP 2: publish the result to the vehicle actuators */
+						orb_publish(ORB_ID(vehicle_attitude_setpoint), att_sp_pub, &att_sp);
+					}
+
+
+				} else if (state.flag_control_manual_enabled) {
+
+					if (state.flag_control_attitude_enabled) {
+
+						/* initialize to current yaw if switching to manual or att control */
+						if (state.flag_control_attitude_enabled != flag_control_attitude_enabled ||
+						    state.flag_control_manual_enabled != flag_control_manual_enabled ||
+						    state.flag_system_armed != flag_system_armed) {
+							att_sp.yaw_body = att.yaw;
+						}
+
+						static bool rc_loss_first_time = true;
+
+						/* if the RC signal is lost, try to stay level and go slowly back down to ground */
+						if (state.rc_signal_lost) {
+							/* the failsafe throttle is stored as a parameter, as it depends on the copter and the payload */
+							param_get(failsafe_throttle_handle, &failsafe_throttle);
+							att_sp.roll_body = 0.0f;
+							att_sp.pitch_body = 0.0f;
+
+							/*
+							 * Only go to failsafe throttle if last known throttle was
+							 * high enough to create some lift to make hovering state likely.
+							 *
+							 * This is to prevent that someone landing, but not disarming his
+							 * multicopter (throttle = 0) does not make it jump up in the air
+							 * if shutting down his remote.
+							 */
+							if (isfinite(manual.throttle) && manual.throttle > 0.2f) {
+								att_sp.thrust = failsafe_throttle;
+
+							} else {
+								att_sp.thrust = 0.0f;
+							}
+
+							/* keep current yaw, do not attempt to go to north orientation,
+							 * since if the pilot regains RC control, he will be lost regarding
+							 * the current orientation.
+							 */
+							if (rc_loss_first_time)
+								att_sp.yaw_body = att.yaw;
+
+							rc_loss_first_time = false;
+
+						} else {
+							rc_loss_first_time = true;
+
+							att_sp.roll_body = manual.roll;
+							att_sp.pitch_body = manual.pitch;
+
+							/* set attitude if arming */
+							if (!flag_control_attitude_enabled && state.flag_system_armed) {
+								att_sp.yaw_body = att.yaw;
+							}
+
+							/* act if stabilization is active or if the (nonsense) direct pass through mode is set */
+							if (state.manual_control_mode == VEHICLE_MANUAL_CONTROL_MODE_SAS ||
+							    state.manual_control_mode == VEHICLE_MANUAL_CONTROL_MODE_DIRECT) {
+
+								if (state.manual_sas_mode == VEHICLE_MANUAL_SAS_MODE_ROLL_PITCH_ABS_YAW_RATE) {
+									rates_sp.yaw = manual.yaw;
+									control_yaw_position = false;
+
+								} else {
+									/*
+									 * This mode SHOULD be the default mode, which is:
+									 * VEHICLE_MANUAL_SAS_MODE_ROLL_PITCH_ABS_YAW_ABS
+									 *
+									 * However, we fall back to this setting for all other (nonsense)
+									 * settings as well.
+									 */
+
+									/* only move setpoint if manual input is != 0 */
+									if ((manual.yaw < -0.01f || 0.01f < manual.yaw) && manual.throttle > 0.3f) {
+										rates_sp.yaw = manual.yaw;
+										control_yaw_position = false;
+										first_time_after_yaw_speed_control = true;
+
+									} else {
+										if (first_time_after_yaw_speed_control) {
+											att_sp.yaw_body = att.yaw;
+											first_time_after_yaw_speed_control = false;
+										}
+
+										control_yaw_position = true;
+									}
+								}
+							}
+
+							att_sp.thrust = manual.throttle;
+							att_sp.timestamp = hrt_absolute_time();
+						}
+
+						/* STEP 2: publish the controller output */
+						orb_publish(ORB_ID(vehicle_attitude_setpoint), att_sp_pub, &att_sp);
+
+						if (motor_test_mode) {
+							printf("testmode");
+							att_sp.roll_body = 0.0f;
+							att_sp.pitch_body = 0.0f;
+							att_sp.yaw_body = 0.0f;
+							att_sp.thrust = 0.1f;
+							att_sp.timestamp = hrt_absolute_time();
+							/* STEP 2: publish the result to the vehicle actuators */
+							orb_publish(ORB_ID(vehicle_attitude_setpoint), att_sp_pub, &att_sp);
+						}
+
+					} else {
+						/* manual rate inputs, from RC control or joystick */
+						if (state.flag_control_rates_enabled &&
+						    state.manual_control_mode == VEHICLE_MANUAL_CONTROL_MODE_RATES) {
+							rates_sp.roll = manual.roll;
+
+							rates_sp.pitch = manual.pitch;
+							rates_sp.yaw = manual.yaw;
+							rates_sp.thrust = manual.throttle;
+							rates_sp.timestamp = hrt_absolute_time();
+						}
+					}
+
+				}
+
+				/** STEP 3: Identify the controller setup to run and set up the inputs correctly */
+				if (state.flag_control_attitude_enabled) {
+					multirotor_control_attitude(&att_sp, &att, &rates_sp, control_yaw_position);
+
+					orb_publish(ORB_ID(vehicle_rates_setpoint), rates_sp_pub, &rates_sp);
+				}
+
+				/* measure in what intervals the controller runs */
+				perf_count(mc_interval_perf);
+
+				float gyro[3];
+
+				/* get current rate setpoint */
+				bool rates_sp_valid = false;
+				orb_check(rates_sp_sub, &rates_sp_valid);
+
+				if (rates_sp_valid) {
+					orb_copy(ORB_ID(vehicle_rates_setpoint), rates_sp_sub, &rates_sp);
+				}
+
+				/* apply controller */
+				gyro[0] = att.rollspeed;
+				gyro[1] = att.pitchspeed;
+				gyro[2] = att.yawspeed;
+
+				multirotor_control_rates(&rates_sp, gyro, &actuators);
+				orb_publish(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, actuator_pub, &actuators);
+
+				/* update state */
+				flag_control_attitude_enabled = state.flag_control_attitude_enabled;
+				flag_control_manual_enabled = state.flag_control_manual_enabled;
+				flag_system_armed = state.flag_system_armed;
+
+				perf_end(mc_loop_perf);
+			} /* end of poll call for attitude updates */
+		} /* end of poll return value check */
+	}
+
+	printf("[multirotor att control] stopping, disarming motors.\n");
+
+	/* kill all outputs */
+	for (unsigned i = 0; i < NUM_ACTUATOR_CONTROLS; i++)
+		actuators.control[i] = 0.0f;
+
+	orb_publish(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, actuator_pub, &actuators);
+
+
+	close(att_sub);
+	close(state_sub);
+	close(manual_sub);
+	close(actuator_pub);
+	close(att_sp_pub);
+
+	perf_print_counter(mc_loop_perf);
+	perf_free(mc_loop_perf);
+
+	fflush(stdout);
+	exit(0);
+}
+
+static void
+usage(const char *reason)
+{
+	if (reason)
+		fprintf(stderr, "%s\n", reason);
+
+	fprintf(stderr, "usage: multirotor_att_control [-m <mode>] [-t] {start|status|stop}\n");
+	fprintf(stderr, "    <mode> is 'rates' or 'attitude'\n");
+	fprintf(stderr, "    -t enables motor test mode with 10%% thrust\n");
+	exit(1);
+}
+
+int multirotor_att_control_main(int argc, char *argv[])
+{
+	int	ch;
+	unsigned int optioncount = 0;
+
+	while ((ch = getopt(argc, argv, "tm:")) != EOF) {
+		switch (ch) {
+		case 't':
+			motor_test_mode = true;
+			optioncount += 1;
+			break;
+
+		case ':':
+			usage("missing parameter");
+			break;
+
+		default:
+			fprintf(stderr, "option: -%c\n", ch);
+			usage("unrecognized option");
+			break;
+		}
+	}
+
+	argc -= optioncount;
+	//argv += optioncount;
+
+	if (argc < 1)
+		usage("missing command");
+
+	if (!strcmp(argv[1 + optioncount], "start")) {
+
+		thread_should_exit = false;
+		mc_task = task_spawn("multirotor_att_control",
+				     SCHED_DEFAULT,
+				     SCHED_PRIORITY_MAX - 15,
+				     2048,
+				     mc_thread_main,
+				     NULL);
+		exit(0);
+	}
+
+	if (!strcmp(argv[1 + optioncount], "stop")) {
+		thread_should_exit = true;
+		exit(0);
+	}
+
+	usage("unrecognized command");
+	exit(1);
+}
diff --git a/src/modules/multirotor_att_control/multirotor_attitude_control.c b/src/modules/multirotor_att_control/multirotor_attitude_control.c
new file mode 100644
index 000000000..76dbb36d3
--- /dev/null
+++ b/src/modules/multirotor_att_control/multirotor_attitude_control.c
@@ -0,0 +1,249 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2008-2012 PX4 Development Team. All rights reserved.
+ *   Author: @author Thomas Gubler <thomasgubler@student.ethz.ch>
+ *           @author Julian Oes <joes@student.ethz.ch>
+ *           @author Laurens Mackay <mackayl@student.ethz.ch>
+ *           @author Tobias Naegeli <naegelit@student.ethz.ch>
+ *           @author Martin Rutschmann <rutmarti@student.ethz.ch>
+ *           @author Lorenz Meier <lm@inf.ethz.ch>
+ *
+ * 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 multirotor_attitude_control.c
+ * Implementation of attitude controller
+ */
+
+#include "multirotor_attitude_control.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <float.h>
+#include <math.h>
+#include <systemlib/pid/pid.h>
+#include <systemlib/param/param.h>
+#include <drivers/drv_hrt.h>
+
+PARAM_DEFINE_FLOAT(MC_YAWPOS_P, 0.3f);
+PARAM_DEFINE_FLOAT(MC_YAWPOS_I, 0.15f);
+PARAM_DEFINE_FLOAT(MC_YAWPOS_D, 0.0f);
+//PARAM_DEFINE_FLOAT(MC_YAWPOS_AWU, 1.0f);
+//PARAM_DEFINE_FLOAT(MC_YAWPOS_LIM, 3.0f);
+
+PARAM_DEFINE_FLOAT(MC_ATT_P, 0.2f);
+PARAM_DEFINE_FLOAT(MC_ATT_I, 0.0f);
+PARAM_DEFINE_FLOAT(MC_ATT_D, 0.05f);
+//PARAM_DEFINE_FLOAT(MC_ATT_AWU, 0.05f);
+//PARAM_DEFINE_FLOAT(MC_ATT_LIM, 0.4f);
+
+//PARAM_DEFINE_FLOAT(MC_ATT_XOFF, 0.0f);
+//PARAM_DEFINE_FLOAT(MC_ATT_YOFF, 0.0f);
+
+struct mc_att_control_params {
+	float yaw_p;
+	float yaw_i;
+	float yaw_d;
+	//float yaw_awu;
+	//float yaw_lim;
+
+	float att_p;
+	float att_i;
+	float att_d;
+	//float att_awu;
+	//float att_lim;
+
+	//float att_xoff;
+	//float att_yoff;
+};
+
+struct mc_att_control_param_handles {
+	param_t yaw_p;
+	param_t yaw_i;
+	param_t yaw_d;
+	//param_t yaw_awu;
+	//param_t yaw_lim;
+
+	param_t att_p;
+	param_t att_i;
+	param_t att_d;
+	//param_t att_awu;
+	//param_t att_lim;
+
+	//param_t att_xoff;
+	//param_t att_yoff;
+};
+
+/**
+ * Initialize all parameter handles and values
+ *
+ */
+static int parameters_init(struct mc_att_control_param_handles *h);
+
+/**
+ * Update all parameters
+ *
+ */
+static int parameters_update(const struct mc_att_control_param_handles *h, struct mc_att_control_params *p);
+
+
+static int parameters_init(struct mc_att_control_param_handles *h)
+{
+	/* PID parameters */
+	h->yaw_p 	=	param_find("MC_YAWPOS_P");
+	h->yaw_i 	=	param_find("MC_YAWPOS_I");
+	h->yaw_d 	=	param_find("MC_YAWPOS_D");
+	//h->yaw_awu 	=	param_find("MC_YAWPOS_AWU");
+	//h->yaw_lim 	=	param_find("MC_YAWPOS_LIM");
+
+	h->att_p 	= 	param_find("MC_ATT_P");
+	h->att_i 	= 	param_find("MC_ATT_I");
+	h->att_d 	= 	param_find("MC_ATT_D");
+	//h->att_awu 	= 	param_find("MC_ATT_AWU");
+	//h->att_lim 	= 	param_find("MC_ATT_LIM");
+
+	//h->att_xoff 	= 	param_find("MC_ATT_XOFF");
+	//h->att_yoff 	= 	param_find("MC_ATT_YOFF");
+
+	return OK;
+}
+
+static int parameters_update(const struct mc_att_control_param_handles *h, struct mc_att_control_params *p)
+{
+	param_get(h->yaw_p, &(p->yaw_p));
+	param_get(h->yaw_i, &(p->yaw_i));
+	param_get(h->yaw_d, &(p->yaw_d));
+	//param_get(h->yaw_awu, &(p->yaw_awu));
+	//param_get(h->yaw_lim, &(p->yaw_lim));
+
+	param_get(h->att_p, &(p->att_p));
+	param_get(h->att_i, &(p->att_i));
+	param_get(h->att_d, &(p->att_d));
+	//param_get(h->att_awu, &(p->att_awu));
+	//param_get(h->att_lim, &(p->att_lim));
+
+	//param_get(h->att_xoff, &(p->att_xoff));
+	//param_get(h->att_yoff, &(p->att_yoff));
+
+	return OK;
+}
+
+void multirotor_control_attitude(const struct vehicle_attitude_setpoint_s *att_sp,
+				 const struct vehicle_attitude_s *att, struct vehicle_rates_setpoint_s *rates_sp, bool control_yaw_position)
+{
+	static uint64_t last_run = 0;
+	static uint64_t last_input = 0;
+	float deltaT = (hrt_absolute_time() - last_run) / 1000000.0f;
+	float dT_input = (hrt_absolute_time() - last_input) / 1000000.0f;
+	last_run = hrt_absolute_time();
+
+	if (last_input != att_sp->timestamp) {
+		last_input = att_sp->timestamp;
+	}
+
+	static int sensor_delay;
+	sensor_delay = hrt_absolute_time() - att->timestamp;
+
+	static int motor_skip_counter = 0;
+
+	static PID_t pitch_controller;
+	static PID_t roll_controller;
+
+	static struct mc_att_control_params p;
+	static struct mc_att_control_param_handles h;
+
+	static bool initialized = false;
+
+	static float yaw_error;
+
+	/* initialize the pid controllers when the function is called for the first time */
+	if (initialized == false) {
+		parameters_init(&h);
+		parameters_update(&h, &p);
+
+		pid_init(&pitch_controller, p.att_p, p.att_i, p.att_d, 1000.0f,
+			 1000.0f, PID_MODE_DERIVATIV_SET);
+		pid_init(&roll_controller, p.att_p, p.att_i, p.att_d, 1000.0f,
+			 1000.0f, PID_MODE_DERIVATIV_SET);
+
+		initialized = true;
+	}
+
+	/* load new parameters with lower rate */
+	if (motor_skip_counter % 500 == 0) {
+		/* update parameters from storage */
+		parameters_update(&h, &p);
+
+		/* apply parameters */
+		pid_set_parameters(&pitch_controller, p.att_p, p.att_i, p.att_d, 1000.0f, 1000.0f);
+		pid_set_parameters(&roll_controller, p.att_p, p.att_i, p.att_d, 1000.0f, 1000.0f);
+	}
+
+	/* reset integral if on ground */
+	if (att_sp->thrust < 0.1f) {
+		pid_reset_integral(&pitch_controller);
+		pid_reset_integral(&roll_controller);
+	}
+
+
+	/* calculate current control outputs */
+
+	/* control pitch (forward) output */
+	rates_sp->pitch = pid_calculate(&pitch_controller, att_sp->pitch_body ,
+					att->pitch, att->pitchspeed, deltaT);
+
+	/* control roll (left/right) output */
+	rates_sp->roll = pid_calculate(&roll_controller, att_sp->roll_body ,
+				       att->roll, att->rollspeed, deltaT);
+
+	if (control_yaw_position) {
+		/* control yaw rate */
+
+		/* positive error: rotate to right, negative error, rotate to left (NED frame) */
+		// yaw_error = _wrap_pi(att_sp->yaw_body - att->yaw);
+
+		yaw_error = att_sp->yaw_body - att->yaw;
+
+		if (yaw_error > M_PI_F) {
+			yaw_error -= M_TWOPI_F;
+
+		} else if (yaw_error < -M_PI_F) {
+			yaw_error += M_TWOPI_F;
+		}
+
+		rates_sp->yaw = p.yaw_p * (yaw_error) - (p.yaw_d * att->yawspeed);
+	}
+
+	rates_sp->thrust = att_sp->thrust;
+
+	motor_skip_counter++;
+}
diff --git a/src/modules/multirotor_att_control/multirotor_attitude_control.h b/src/modules/multirotor_att_control/multirotor_attitude_control.h
new file mode 100644
index 000000000..2cf83e443
--- /dev/null
+++ b/src/modules/multirotor_att_control/multirotor_attitude_control.h
@@ -0,0 +1,57 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+ *   Author: @author Thomas Gubler <thomasgubler@student.ethz.ch>
+ *           @author Julian Oes <joes@student.ethz.ch>
+ *           @author Laurens Mackay <mackayl@student.ethz.ch>
+ *           @author Tobias Naegeli <naegelit@student.ethz.ch>
+ *           @author Martin Rutschmann <rutmarti@student.ethz.ch>
+ *           @author Lorenz Meier <lm@inf.ethz.ch>
+ *
+ * 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 multirotor_attitude_control.h
+ * Attitude control for multi rotors.
+ */
+
+#ifndef MULTIROTOR_ATTITUDE_CONTROL_H_
+#define MULTIROTOR_ATTITUDE_CONTROL_H_
+
+#include <uORB/uORB.h>
+#include <uORB/topics/vehicle_attitude.h>
+#include <uORB/topics/vehicle_attitude_setpoint.h>
+#include <uORB/topics/vehicle_rates_setpoint.h>
+#include <uORB/topics/actuator_controls.h>
+
+void multirotor_control_attitude(const struct vehicle_attitude_setpoint_s *att_sp,
+				 const struct vehicle_attitude_s *att, struct vehicle_rates_setpoint_s *rates_sp, bool control_yaw_position);
+
+#endif /* MULTIROTOR_ATTITUDE_CONTROL_H_ */
diff --git a/src/modules/multirotor_att_control/multirotor_rate_control.c b/src/modules/multirotor_att_control/multirotor_rate_control.c
new file mode 100644
index 000000000..deba1ac03
--- /dev/null
+++ b/src/modules/multirotor_att_control/multirotor_rate_control.c
@@ -0,0 +1,230 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+ *   Author: Tobias Naegeli <naegelit@student.ethz.ch>
+ *           Lorenz Meier <lm@inf.ethz.ch>
+ *
+ * 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 multirotor_rate_control.c
+ *
+ * Implementation of rate controller
+ *
+ * @author Tobias Naegeli <naegelit@student.ethz.ch>
+ * @author Lorenz Meier <lm@inf.ethz.ch>
+ */
+
+#include "multirotor_rate_control.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <float.h>
+#include <math.h>
+#include <systemlib/pid/pid.h>
+#include <systemlib/param/param.h>
+#include <systemlib/err.h>
+#include <drivers/drv_hrt.h>
+
+PARAM_DEFINE_FLOAT(MC_YAWRATE_P, 0.0f); /* same on Flamewheel */
+PARAM_DEFINE_FLOAT(MC_YAWRATE_D, 0.0f);
+PARAM_DEFINE_FLOAT(MC_YAWRATE_I, 0.0f);
+//PARAM_DEFINE_FLOAT(MC_YAWRATE_AWU, 0.0f);
+//PARAM_DEFINE_FLOAT(MC_YAWRATE_LIM, 1.0f);
+
+PARAM_DEFINE_FLOAT(MC_ATTRATE_P, 0.0f); /* 0.15 F405 Flamewheel */
+PARAM_DEFINE_FLOAT(MC_ATTRATE_D, 0.0f);
+PARAM_DEFINE_FLOAT(MC_ATTRATE_I, 0.0f);
+//PARAM_DEFINE_FLOAT(MC_ATTRATE_AWU, 0.05f);
+//PARAM_DEFINE_FLOAT(MC_ATTRATE_LIM, 1.0f);	/**< roughly < 500 deg/s limit */
+
+struct mc_rate_control_params {
+
+	float yawrate_p;
+	float yawrate_d;
+	float yawrate_i;
+	//float yawrate_awu;
+	//float yawrate_lim;
+
+	float attrate_p;
+	float attrate_d;
+	float attrate_i;
+	//float attrate_awu;
+	//float attrate_lim;
+
+	float rate_lim;
+};
+
+struct mc_rate_control_param_handles {
+
+	param_t yawrate_p;
+	param_t yawrate_i;
+	param_t yawrate_d;
+	//param_t yawrate_awu;
+	//param_t yawrate_lim;
+
+	param_t attrate_p;
+	param_t attrate_i;
+	param_t attrate_d;
+	//param_t attrate_awu;
+	//param_t attrate_lim;
+};
+
+/**
+ * Initialize all parameter handles and values
+ *
+ */
+static int parameters_init(struct mc_rate_control_param_handles *h);
+
+/**
+ * Update all parameters
+ *
+ */
+static int parameters_update(const struct mc_rate_control_param_handles *h, struct mc_rate_control_params *p);
+
+
+static int parameters_init(struct mc_rate_control_param_handles *h)
+{
+	/* PID parameters */
+	h->yawrate_p 	=	param_find("MC_YAWRATE_P");
+	h->yawrate_i 	=	param_find("MC_YAWRATE_I");
+	h->yawrate_d 	=	param_find("MC_YAWRATE_D");
+	//h->yawrate_awu 	=	param_find("MC_YAWRATE_AWU");
+	//h->yawrate_lim 	=	param_find("MC_YAWRATE_LIM");
+
+	h->attrate_p 	= 	param_find("MC_ATTRATE_P");
+	h->attrate_i 	= 	param_find("MC_ATTRATE_I");
+	h->attrate_d 	= 	param_find("MC_ATTRATE_D");
+	//h->attrate_awu 	= 	param_find("MC_ATTRATE_AWU");
+	//h->attrate_lim 	= 	param_find("MC_ATTRATE_LIM");
+
+	return OK;
+}
+
+static int parameters_update(const struct mc_rate_control_param_handles *h, struct mc_rate_control_params *p)
+{
+	param_get(h->yawrate_p, &(p->yawrate_p));
+	param_get(h->yawrate_i, &(p->yawrate_i));
+	param_get(h->yawrate_d, &(p->yawrate_d));
+	//param_get(h->yawrate_awu, &(p->yawrate_awu));
+	//param_get(h->yawrate_lim, &(p->yawrate_lim));
+
+	param_get(h->attrate_p, &(p->attrate_p));
+	param_get(h->attrate_i, &(p->attrate_i));
+	param_get(h->attrate_d, &(p->attrate_d));
+	//param_get(h->attrate_awu, &(p->attrate_awu));
+	//param_get(h->attrate_lim, &(p->attrate_lim));
+
+	return OK;
+}
+
+void multirotor_control_rates(const struct vehicle_rates_setpoint_s *rate_sp,
+			      const float rates[], struct actuator_controls_s *actuators)
+{
+	static float roll_control_last  = 0;
+	static float pitch_control_last = 0;
+	static uint64_t last_run = 0;
+	const float deltaT = (hrt_absolute_time() - last_run) / 1000000.0f;
+	static uint64_t last_input = 0;
+
+	float dT_input = (hrt_absolute_time() - last_input) / 1000000.0f;
+
+	if (last_input != rate_sp->timestamp) {
+		last_input = rate_sp->timestamp;
+	}
+
+	last_run = hrt_absolute_time();
+
+	static int motor_skip_counter = 0;
+
+	static struct mc_rate_control_params p;
+	static struct mc_rate_control_param_handles h;
+
+	static bool initialized = false;
+
+	/* initialize the pid controllers when the function is called for the first time */
+	if (initialized == false) {
+		parameters_init(&h);
+		parameters_update(&h, &p);
+		initialized = true;
+	}
+
+	/* load new parameters with lower rate */
+	if (motor_skip_counter % 2500 == 0) {
+		/* update parameters from storage */
+		parameters_update(&h, &p);
+		// warnx("rate ctrl: p.yawrate_p: %8.4f, loop: %d Hz, input: %d Hz",
+		// 	(double)p.yawrate_p, (int)(1.0f/deltaT), (int)(1.0f/dT_input));
+	}
+
+	/* calculate current control outputs */
+
+	/* control pitch (forward) output */
+	float pitch_control = p.attrate_p * (rate_sp->pitch - rates[1]) - (p.attrate_d * pitch_control_last);
+
+	/* increase resilience to faulty control inputs */
+	if (isfinite(pitch_control)) {
+		pitch_control_last = pitch_control;
+
+	} else {
+		pitch_control = 0.0f;
+		warnx("rej. NaN ctrl pitch");
+	}
+
+	/* control roll (left/right) output */
+	float roll_control = p.attrate_p * (rate_sp->roll - rates[0]) - (p.attrate_d * roll_control_last);
+
+	/* increase resilience to faulty control inputs */
+	if (isfinite(roll_control)) {
+		roll_control_last = roll_control;
+
+	} else {
+		roll_control = 0.0f;
+		warnx("rej. NaN ctrl roll");
+	}
+
+	/* control yaw rate */
+	float yaw_rate_control = p.yawrate_p * (rate_sp->yaw - rates[2]);
+
+	/* increase resilience to faulty control inputs */
+	if (!isfinite(yaw_rate_control)) {
+		yaw_rate_control = 0.0f;
+		warnx("rej. NaN ctrl yaw");
+	}
+
+	actuators->control[0] = roll_control;
+	actuators->control[1] = pitch_control;
+	actuators->control[2] = yaw_rate_control;
+	actuators->control[3] = rate_sp->thrust;
+
+	motor_skip_counter++;
+}
diff --git a/src/modules/multirotor_att_control/multirotor_rate_control.h b/src/modules/multirotor_att_control/multirotor_rate_control.h
new file mode 100644
index 000000000..03dec317a
--- /dev/null
+++ b/src/modules/multirotor_att_control/multirotor_rate_control.h
@@ -0,0 +1,56 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+ *   Author: @author Thomas Gubler <thomasgubler@student.ethz.ch>
+ *           @author Julian Oes <joes@student.ethz.ch>
+ *           @author Laurens Mackay <mackayl@student.ethz.ch>
+ *           @author Tobias Naegeli <naegelit@student.ethz.ch>
+ *           @author Martin Rutschmann <rutmarti@student.ethz.ch>
+ *           @author Lorenz Meier <lm@inf.ethz.ch>
+ *
+ * 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 multirotor_attitude_control.h
+ * Attitude control for multi rotors.
+ */
+
+#ifndef MULTIROTOR_RATE_CONTROL_H_
+#define MULTIROTOR_RATE_CONTROL_H_
+
+#include <uORB/uORB.h>
+#include <uORB/topics/vehicle_attitude.h>
+#include <uORB/topics/vehicle_rates_setpoint.h>
+#include <uORB/topics/actuator_controls.h>
+
+void multirotor_control_rates(const struct vehicle_rates_setpoint_s *rate_sp,
+			      const float rates[], struct actuator_controls_s *actuators);
+
+#endif /* MULTIROTOR_RATE_CONTROL_H_ */
diff --git a/src/modules/multirotor_pos_control/module.mk b/src/modules/multirotor_pos_control/module.mk
new file mode 100644
index 000000000..d04847745
--- /dev/null
+++ b/src/modules/multirotor_pos_control/module.mk
@@ -0,0 +1,41 @@
+############################################################################
+#
+#   Copyright (c) 2012, 2013 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.
+#
+############################################################################
+
+#
+# Build multirotor position control
+#
+
+MODULE_COMMAND	= multirotor_pos_control
+
+SRCS		= multirotor_pos_control.c \
+		  multirotor_pos_control_params.c
diff --git a/src/modules/multirotor_pos_control/multirotor_pos_control.c b/src/modules/multirotor_pos_control/multirotor_pos_control.c
new file mode 100644
index 000000000..7b8d83aa8
--- /dev/null
+++ b/src/modules/multirotor_pos_control/multirotor_pos_control.c
@@ -0,0 +1,238 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2008-2012 PX4 Development Team. All rights reserved.
+ *   Author: Lorenz Meier <lm@inf.ethz.ch>
+ *
+ * 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 multirotor_pos_control.c
+ *
+ * Skeleton for multirotor position controller
+ */
+
+#include <nuttx/config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <debug.h>
+#include <termios.h>
+#include <time.h>
+#include <sys/prctl.h>
+#include <drivers/drv_hrt.h>
+#include <uORB/uORB.h>
+#include <uORB/topics/vehicle_status.h>
+#include <uORB/topics/vehicle_attitude.h>
+#include <uORB/topics/manual_control_setpoint.h>
+#include <uORB/topics/vehicle_attitude_setpoint.h>
+#include <uORB/topics/vehicle_local_position_setpoint.h>
+#include <uORB/topics/vehicle_vicon_position.h>
+#include <systemlib/systemlib.h>
+
+#include "multirotor_pos_control_params.h"
+
+
+static bool thread_should_exit = false;		/**< Deamon exit flag */
+static bool thread_running = false;		/**< Deamon status flag */
+static int deamon_task;				/**< Handle of deamon task / thread */
+
+__EXPORT int multirotor_pos_control_main(int argc, char *argv[]);
+
+/**
+ * Mainloop of position controller.
+ */
+static int multirotor_pos_control_thread_main(int argc, char *argv[]);
+
+/**
+ * Print the correct usage.
+ */
+static void usage(const char *reason);
+
+static void
+usage(const char *reason)
+{
+	if (reason)
+		fprintf(stderr, "%s\n", reason);
+	fprintf(stderr, "usage: deamon {start|stop|status} [-p <additional params>]\n\n");
+	exit(1);
+}
+
+/**
+ * The deamon app only briefly exists to start
+ * the background job. The stack size assigned in the
+ * Makefile does only apply to this management task.
+ * 
+ * The actual stack size should be set in the call
+ * to task_spawn().
+ */
+int multirotor_pos_control_main(int argc, char *argv[])
+{
+	if (argc < 1)
+		usage("missing command");
+
+	if (!strcmp(argv[1], "start")) {
+
+		if (thread_running) {
+			printf("multirotor pos control already running\n");
+			/* this is not an error */
+			exit(0);
+		}
+
+		thread_should_exit = false;
+		deamon_task = task_spawn("multirotor pos control",
+					 SCHED_DEFAULT,
+					 SCHED_PRIORITY_MAX - 60,
+					 4096,
+					 multirotor_pos_control_thread_main,
+					 (argv) ? (const char **)&argv[2] : (const char **)NULL);
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "stop")) {
+		thread_should_exit = true;
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "status")) {
+		if (thread_running) {
+			printf("\tmultirotor pos control app is running\n");
+		} else {
+			printf("\tmultirotor pos control app not started\n");
+		}
+		exit(0);
+	}
+
+	usage("unrecognized command");
+	exit(1);
+}
+
+static int
+multirotor_pos_control_thread_main(int argc, char *argv[])
+{
+	/* welcome user */
+	printf("[multirotor pos control] Control started, taking over position control\n");
+
+	/* structures */
+	struct vehicle_status_s state;
+	struct vehicle_attitude_s att;
+	//struct vehicle_global_position_setpoint_s global_pos_sp;
+	struct vehicle_local_position_setpoint_s local_pos_sp;
+	struct vehicle_vicon_position_s local_pos;
+	struct manual_control_setpoint_s manual;
+	struct vehicle_attitude_setpoint_s att_sp;
+
+	/* subscribe to attitude, motor setpoints and system state */
+	int att_sub = orb_subscribe(ORB_ID(vehicle_attitude));
+	int state_sub = orb_subscribe(ORB_ID(vehicle_status));
+	int manual_sub = orb_subscribe(ORB_ID(manual_control_setpoint));
+	int local_pos_sub = orb_subscribe(ORB_ID(vehicle_vicon_position));
+	//int global_pos_sp_sub = orb_subscribe(ORB_ID(vehicle_global_position_setpoint));
+	int local_pos_sp_sub = orb_subscribe(ORB_ID(vehicle_local_position_setpoint));
+
+	/* publish attitude setpoint */
+	orb_advert_t att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &att_sp);
+
+	thread_running = true;
+
+	int loopcounter = 0;
+
+	struct multirotor_position_control_params p;
+	struct multirotor_position_control_param_handles h;
+	parameters_init(&h);
+	parameters_update(&h, &p);
+
+
+	while (1) {
+		/* get a local copy of the vehicle state */
+		orb_copy(ORB_ID(vehicle_status), state_sub, &state);
+		/* get a local copy of manual setpoint */
+		orb_copy(ORB_ID(manual_control_setpoint), manual_sub, &manual);
+		/* get a local copy of attitude */
+		orb_copy(ORB_ID(vehicle_attitude), att_sub, &att);
+		/* get a local copy of local position */
+		orb_copy(ORB_ID(vehicle_vicon_position), local_pos_sub, &local_pos);
+		/* get a local copy of local position setpoint */
+		orb_copy(ORB_ID(vehicle_local_position_setpoint), local_pos_sp_sub, &local_pos_sp);
+
+		if (loopcounter == 500) {
+			parameters_update(&h, &p);
+			loopcounter = 0;
+		}
+
+		// if (state.state_machine == SYSTEM_STATE_AUTO) {
+			
+			// XXX IMPLEMENT POSITION CONTROL HERE
+
+			float dT = 1.0f / 50.0f;
+
+			float x_setpoint = 0.0f;
+
+			// XXX enable switching between Vicon and local position estimate
+			/* local pos is the Vicon position */
+
+			// XXX just an example, lacks rotation around world-body transformation
+			att_sp.pitch_body = (local_pos.x - x_setpoint) * p.p;
+			att_sp.roll_body = 0.0f;
+			att_sp.yaw_body = 0.0f;
+			att_sp.thrust = 0.3f;
+			att_sp.timestamp = hrt_absolute_time();
+
+			/* publish new attitude setpoint */
+			orb_publish(ORB_ID(vehicle_attitude_setpoint), att_sp_pub, &att_sp);
+		// } else if (state.state_machine == SYSTEM_STATE_STABILIZED) {
+			/* set setpoint to current position */
+			// XXX select pos reset channel on remote
+			/* reset setpoint to current position  (position hold) */
+			// if (1 == 2) {
+			// 	local_pos_sp.x = local_pos.x;
+			// 	local_pos_sp.y = local_pos.y;
+			// 	local_pos_sp.z = local_pos.z;
+			// 	local_pos_sp.yaw = att.yaw;
+			// }
+		// }
+
+		/* run at approximately 50 Hz */
+		usleep(20000);
+		loopcounter++;
+
+	}
+
+	printf("[multirotor pos control] ending now...\n");
+
+	thread_running = false;
+
+	fflush(stdout);
+	return 0;
+}
+
diff --git a/src/modules/multirotor_pos_control/multirotor_pos_control_params.c b/src/modules/multirotor_pos_control/multirotor_pos_control_params.c
new file mode 100644
index 000000000..6b73dc405
--- /dev/null
+++ b/src/modules/multirotor_pos_control/multirotor_pos_control_params.c
@@ -0,0 +1,62 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+ *   Author: Tobias Naegeli <naegelit@student.ethz.ch>
+ *           Lorenz Meier <lm@inf.ethz.ch>
+ *
+ * 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 multirotor_position_control_params.c
+ * 
+ * Parameters for EKF filter
+ */
+
+#include "multirotor_pos_control_params.h"
+
+/* Extended Kalman Filter covariances */
+
+/* controller parameters */
+PARAM_DEFINE_FLOAT(MC_POS_P, 0.2f);
+
+int parameters_init(struct multirotor_position_control_param_handles *h)
+{
+	/* PID parameters */
+	h->p 	=	param_find("MC_POS_P");
+
+	return OK;
+}
+
+int parameters_update(const struct multirotor_position_control_param_handles *h, struct multirotor_position_control_params *p)
+{
+	param_get(h->p, &(p->p));
+
+	return OK;
+}
diff --git a/src/modules/multirotor_pos_control/multirotor_pos_control_params.h b/src/modules/multirotor_pos_control/multirotor_pos_control_params.h
new file mode 100644
index 000000000..274f6c22a
--- /dev/null
+++ b/src/modules/multirotor_pos_control/multirotor_pos_control_params.h
@@ -0,0 +1,66 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+ *   Author: Tobias Naegeli <naegelit@student.ethz.ch>
+ *           Lorenz Meier <lm@inf.ethz.ch>
+ *
+ * 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 multirotor_position_control_params.h
+ * 
+ * Parameters for position controller
+ */
+
+#include <systemlib/param/param.h>
+
+struct multirotor_position_control_params {
+	float p;
+	float i;
+	float d;
+};
+
+struct multirotor_position_control_param_handles {
+	param_t p;
+	param_t i;
+	param_t d;
+};
+
+/**
+ * Initialize all parameter handles and values
+ *
+ */
+int parameters_init(struct multirotor_position_control_param_handles *h);
+
+/**
+ * Update all parameters
+ *
+ */
+int parameters_update(const struct multirotor_position_control_param_handles *h, struct multirotor_position_control_params *p);
diff --git a/src/modules/multirotor_pos_control/position_control.c b/src/modules/multirotor_pos_control/position_control.c
new file mode 100644
index 000000000..9c53a5bf6
--- /dev/null
+++ b/src/modules/multirotor_pos_control/position_control.c
@@ -0,0 +1,235 @@
+// /****************************************************************************
+//  *
+//  *   Copyright (C) 2008-2012 PX4 Development Team. All rights reserved.
+//  *   Author: @author Lorenz Meier <lm@inf.ethz.ch>
+//  *           @author Laurens Mackay <mackayl@student.ethz.ch>
+//  *           @author Tobias Naegeli <naegelit@student.ethz.ch>
+//  *           @author Martin Rutschmann <rutmarti@student.ethz.ch>
+//  *
+//  * 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 multirotor_position_control.c
+//  * Implementation of the position control for a multirotor VTOL
+//  */
+
+// #include <stdio.h>
+// #include <stdlib.h>
+// #include <stdio.h>
+// #include <stdint.h>
+// #include <math.h>
+// #include <stdbool.h>
+// #include <float.h>
+// #include <systemlib/pid/pid.h>
+
+// #include "multirotor_position_control.h"
+
+// void control_multirotor_position(const struct vehicle_state_s *vstatus, const struct vehicle_manual_control_s *manual,
+//  const struct vehicle_attitude_s *att, const struct vehicle_local_position_s *local_pos,
+//  const struct vehicle_local_position_setpoint_s *local_pos_sp, struct vehicle_attitude_setpoint_s *att_sp)
+// {
+// 	static PID_t distance_controller;
+
+// 	static int read_ret;
+// 	static global_data_position_t position_estimated;
+
+// 	static uint16_t counter;
+
+// 	static bool initialized;
+// 	static uint16_t pm_counter;
+
+// 	static float lat_next;
+// 	static float lon_next;
+
+// 	static float pitch_current;
+
+// 	static float thrust_total;
+
+
+// 	if (initialized == false) {
+
+// 		pid_init(&distance_controller,
+// 			 global_data_parameter_storage->pm.param_values[PARAM_PID_POS_P],
+// 			 global_data_parameter_storage->pm.param_values[PARAM_PID_POS_I],
+// 			 global_data_parameter_storage->pm.param_values[PARAM_PID_POS_D],
+// 			 global_data_parameter_storage->pm.param_values[PARAM_PID_POS_AWU],
+// 			 PID_MODE_DERIVATIV_CALC, 150);//150
+
+// //		pid_pos_lim = global_data_parameter_storage->pm.param_values[PARAM_PID_POS_LIM];
+// //		pid_pos_z_lim = global_data_parameter_storage->pm.param_values[PARAM_PID_POS_Z_LIM];
+
+// 		thrust_total = 0.0f;
+
+// 		/* Position initialization */
+// 		/* Wait for new position estimate */
+// 		do {
+// 			read_ret = read_lock_position(&position_estimated);
+// 		} while (read_ret != 0);
+
+// 		lat_next = position_estimated.lat;
+// 		lon_next = position_estimated.lon;
+
+// 		/* attitude initialization */
+// 		global_data_lock(&global_data_attitude->access_conf);
+// 		pitch_current = global_data_attitude->pitch;
+// 		global_data_unlock(&global_data_attitude->access_conf);
+
+// 		initialized = true;
+// 	}
+
+// 	/* load new parameters with 10Hz */
+// 	if (counter % 50 == 0) {
+// 		if (global_data_trylock(&global_data_parameter_storage->access_conf) == 0) {
+// 			/* check whether new parameters are available */
+// 			if (global_data_parameter_storage->counter > pm_counter) {
+// 				pid_set_parameters(&distance_controller,
+// 						   global_data_parameter_storage->pm.param_values[PARAM_PID_POS_P],
+// 						   global_data_parameter_storage->pm.param_values[PARAM_PID_POS_I],
+// 						   global_data_parameter_storage->pm.param_values[PARAM_PID_POS_D],
+// 						   global_data_parameter_storage->pm.param_values[PARAM_PID_POS_AWU]);
+
+// //
+// //				pid_pos_lim = global_data_parameter_storage->pm.param_values[PARAM_PID_POS_LIM];
+// //				pid_pos_z_lim = global_data_parameter_storage->pm.param_values[PARAM_PID_POS_Z_LIM];
+
+// 				pm_counter = global_data_parameter_storage->counter;
+// 				printf("Position controller changed pid parameters\n");
+// 			}
+// 		}
+
+// 		global_data_unlock(&global_data_parameter_storage->access_conf);
+// 	}
+
+
+// 	/* Wait for new position estimate */
+// 	do {
+// 		read_ret = read_lock_position(&position_estimated);
+// 	} while (read_ret != 0);
+
+// 	/* Get next waypoint */ //TODO: add local copy
+
+// 	if (0 == global_data_trylock(&global_data_position_setpoint->access_conf)) {
+// 		lat_next = global_data_position_setpoint->x;
+// 		lon_next = global_data_position_setpoint->y;
+// 		global_data_unlock(&global_data_position_setpoint->access_conf);
+// 	}
+
+// 	/* Get distance to waypoint */
+// 	float distance_to_waypoint = get_distance_to_next_waypoint(position_estimated.lat , position_estimated.lon, lat_next, lon_next);
+// //	if(counter % 5 == 0)
+// //		printf("distance_to_waypoint: %.4f\n", distance_to_waypoint);
+
+// 	/* Get bearing to waypoint (direction on earth surface to next waypoint) */
+// 	float bearing = get_bearing_to_next_waypoint(position_estimated.lat, position_estimated.lon, lat_next, lon_next);
+
+// 	if (counter % 5 == 0)
+// 		printf("bearing: %.4f\n", bearing);
+
+// 	/* Calculate speed in direction of bearing (needed for controller) */
+// 	float speed_norm = sqrtf(position_estimated.vx  * position_estimated.vx + position_estimated.vy * position_estimated.vy);
+// //	if(counter % 5 == 0)
+// //		printf("speed_norm: %.4f\n", speed_norm);
+// 	float speed_to_waypoint = 0; //(position_estimated.vx * cosf(bearing) + position_estimated.vy * sinf(bearing))/speed_norm; //FIXME, TODO: re-enable this once we have a full estimate of the speed, then we can do a PID for the distance controller
+
+// 	/* Control Thrust in bearing direction  */
+// 	float horizontal_thrust = -pid_calculate(&distance_controller, 0, distance_to_waypoint, speed_to_waypoint,
+// 				  CONTROL_PID_POSITION_INTERVAL); //TODO: maybe this "-" sign is an error somewhere else
+
+// //	if(counter % 5 == 0)
+// //		printf("horizontal thrust: %.4f\n", horizontal_thrust);
+
+// 	/* Get total thrust (from remote for now) */
+// 	if (0 == global_data_trylock(&global_data_rc_channels->access_conf)) {
+// 		thrust_total = (float)global_data_rc_channels->chan[THROTTLE].scale; 												//TODO: how should we use the RC_CHANNELS_FUNCTION enum?
+// 		global_data_unlock(&global_data_rc_channels->access_conf);
+// 	}
+
+// 	const float max_gas = 500.0f;
+// 	thrust_total *= max_gas / 20000.0f; //TODO: check this
+// 	thrust_total += max_gas / 2.0f;
+
+
+// 	if (horizontal_thrust > thrust_total) {
+// 		horizontal_thrust = thrust_total;
+
+// 	} else if (horizontal_thrust < -thrust_total) {
+// 		horizontal_thrust = -thrust_total;
+// 	}
+
+
+
+// 	//TODO: maybe we want to add a speed controller later...
+
+// 	/* Calclulate thrust in east and north direction */
+// 	float thrust_north = cosf(bearing) * horizontal_thrust;
+// 	float thrust_east = sinf(bearing) * horizontal_thrust;
+
+// 	if (counter % 10 == 0) {
+// 		printf("thrust north: %.4f\n", thrust_north);
+// 		printf("thrust east: %.4f\n", thrust_east);
+// 		fflush(stdout);
+// 	}
+
+// 	/* Get current attitude */
+// 	if (0 == global_data_trylock(&global_data_attitude->access_conf)) {
+// 		pitch_current = global_data_attitude->pitch;
+// 		global_data_unlock(&global_data_attitude->access_conf);
+// 	}
+
+// 	/* Get desired pitch & roll */
+// 	float pitch_desired = 0.0f;
+// 	float roll_desired = 0.0f;
+
+// 	if (thrust_total != 0) {
+// 		float pitch_fraction = -thrust_north / thrust_total;
+// 		float roll_fraction = thrust_east / (cosf(pitch_current) * thrust_total);
+
+// 		if (roll_fraction < -1) {
+// 			roll_fraction = -1;
+
+// 		} else if (roll_fraction > 1) {
+// 			roll_fraction = 1;
+// 		}
+
+// //		if(counter % 5 == 0)
+// //		{
+// //			printf("pitch_fraction: %.4f, roll_fraction: %.4f\n",pitch_fraction, roll_fraction);
+// //			fflush(stdout);
+// //		}
+
+// 		pitch_desired = asinf(pitch_fraction);
+// 		roll_desired = asinf(roll_fraction);
+// 	}
+
+// 	att_sp.roll = roll_desired;
+// 	att_sp.pitch = pitch_desired;
+
+// 	counter++;
+// }
diff --git a/src/modules/multirotor_pos_control/position_control.h b/src/modules/multirotor_pos_control/position_control.h
new file mode 100644
index 000000000..2144ebc34
--- /dev/null
+++ b/src/modules/multirotor_pos_control/position_control.h
@@ -0,0 +1,50 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2008-2012 PX4 Development Team. All rights reserved.
+ *   Author: @author Lorenz Meier <lm@inf.ethz.ch>
+ *           @author Laurens Mackay <mackayl@student.ethz.ch>
+ *           @author Tobias Naegeli <naegelit@student.ethz.ch>
+ *           @author Martin Rutschmann <rutmarti@student.ethz.ch>
+ *
+ * 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 multirotor_position_control.h
+ * Definition of the position control for a multirotor VTOL
+ */
+
+// #ifndef POSITION_CONTROL_H_
+// #define POSITION_CONTROL_H_
+
+// void control_multirotor_position(const struct vehicle_state_s *vstatus, const struct vehicle_manual_control_s *manual,
+//  const struct vehicle_attitude_s *att, const struct vehicle_local_position_s *local_pos,
+//  const struct vehicle_local_position_setpoint_s *local_pos_sp, struct vehicle_attitude_setpoint_s *att_sp);
+
+// #endif /* POSITION_CONTROL_H_ */
diff --git a/src/modules/position_estimator/.context b/src/modules/position_estimator/.context
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/src/modules/position_estimator/.context
diff --git a/src/modules/position_estimator/module.mk b/src/modules/position_estimator/module.mk
new file mode 100644
index 000000000..f64095d9d
--- /dev/null
+++ b/src/modules/position_estimator/module.mk
@@ -0,0 +1,44 @@
+############################################################################
+#
+#   Copyright (c) 2012, 2013 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.
+#
+############################################################################
+
+#
+# Makefile to build the position estimator
+#
+
+MODULE_COMMAND		= position_estimator
+
+# XXX this should be converted to a deamon, its a pretty bad example app
+MODULE_PRIORITY	 	= SCHED_PRIORITY_DEFAULT
+MODULE_STACKSIZE	= 4096
+
+SRCS		 	= position_estimator_main.c
diff --git a/src/modules/position_estimator/position_estimator_main.c b/src/modules/position_estimator/position_estimator_main.c
new file mode 100644
index 000000000..e84945299
--- /dev/null
+++ b/src/modules/position_estimator/position_estimator_main.c
@@ -0,0 +1,423 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2008-2012 PX4 Development Team. All rights reserved.
+ *   Author: Tobias Naegeli <naegelit@student.ethz.ch>
+ *			 Thomas Gubler <thomasgubler@student.ethz.ch>
+ *           Julian Oes <joes@student.ethz.ch>
+ *           Lorenz Meier <lm@inf.ethz.ch>
+ *
+ * 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 position_estimator_main.c
+ * Model-identification based position estimator for multirotors
+ */
+
+#include <nuttx/config.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <fcntl.h>
+#include <float.h>
+#include <nuttx/sched.h>
+#include <sys/prctl.h>
+#include <termios.h>
+#include <errno.h>
+#include <limits.h>
+#include <math.h>
+#include <uORB/uORB.h>
+#include <uORB/topics/vehicle_status.h>
+#include <uORB/topics/vehicle_attitude.h>
+#include <uORB/topics/vehicle_gps_position.h>
+#include <uORB/topics/vehicle_global_position.h>
+#include <uORB/topics/vehicle_local_position.h>
+#include <poll.h>
+
+#define N_STATES 6
+#define ERROR_COVARIANCE_INIT 3
+#define R_EARTH 6371000.0
+
+#define PROJECTION_INITIALIZE_COUNTER_LIMIT 5000
+#define REPROJECTION_COUNTER_LIMIT 125
+
+__EXPORT int position_estimator_main(int argc, char *argv[]);
+
+static uint16_t position_estimator_counter_position_information;
+
+/* values for map projection */
+static double phi_1;
+static double sin_phi_1;
+static double cos_phi_1;
+static double lambda_0;
+static double scale;
+
+/**
+ * Initializes the map transformation.
+ *
+ * Initializes the transformation between the geographic coordinate system and the azimuthal equidistant plane
+ * @param lat in degrees (47.1234567°, not 471234567°)
+ * @param lon in degrees (8.1234567°, not 81234567°)
+ */
+static void map_projection_init(double lat_0, double lon_0) //lat_0, lon_0 are expected to be in correct format: -> 47.1234567 and not 471234567
+{
+	/* notation and formulas according to: http://mathworld.wolfram.com/AzimuthalEquidistantProjection.html */
+	phi_1 = lat_0 / 180.0 * M_PI;
+	lambda_0 = lon_0 / 180.0 * M_PI;
+
+	sin_phi_1 = sin(phi_1);
+	cos_phi_1 = cos(phi_1);
+
+	/* calculate local scale by using the relation of true distance and the distance on plane */ //TODO: this is a quick solution, there are probably easier ways to determine the scale
+
+	/* 1) calculate true distance d on sphere to a point: http://www.movable-type.co.uk/scripts/latlong.html */
+	const double r_earth = 6371000;
+
+	double lat1 = phi_1;
+	double lon1 = lambda_0;
+
+	double lat2 = phi_1 + 0.5 / 180 * M_PI;
+	double lon2 = lambda_0 + 0.5 / 180 * M_PI;
+	double sin_lat_2 = sin(lat2);
+	double cos_lat_2 = cos(lat2);
+	double d = acos(sin(lat1) * sin_lat_2 + cos(lat1) * cos_lat_2 * cos(lon2 - lon1)) * r_earth;
+
+	/* 2) calculate distance rho on plane */
+	double k_bar = 0;
+	double c =  acos(sin_phi_1 * sin_lat_2 + cos_phi_1 * cos_lat_2 * cos(lon2 - lambda_0));
+
+	if (0 != c)
+		k_bar = c / sin(c);
+
+	double x2 = k_bar * (cos_lat_2 * sin(lon2 - lambda_0)); //Projection of point 2 on plane
+	double y2 = k_bar * ((cos_phi_1 * sin_lat_2 - sin_phi_1 * cos_lat_2 * cos(lon2 - lambda_0)));
+	double rho = sqrt(pow(x2, 2) + pow(y2, 2));
+
+	scale = d / rho;
+
+}
+
+/**
+ * Transforms a point in the geographic coordinate system to the local azimuthal equidistant plane
+ * @param x north
+ * @param y east
+ * @param lat in degrees (47.1234567°, not 471234567°)
+ * @param lon in degrees (8.1234567°, not 81234567°)
+ */
+static void map_projection_project(double lat, double lon, float *x, float *y)
+{
+	/* notation and formulas accoring to: http://mathworld.wolfram.com/AzimuthalEquidistantProjection.html */
+	double phi = lat / 180.0 * M_PI;
+	double lambda = lon / 180.0 * M_PI;
+
+	double sin_phi = sin(phi);
+	double cos_phi = cos(phi);
+
+	double k_bar = 0;
+	/* using small angle approximation (formula in comment is without aproximation) */
+	double c =  acos(sin_phi_1 * sin_phi + cos_phi_1 * cos_phi * (1 - pow((lambda - lambda_0), 2) / 2)); //double c =  acos( sin_phi_1 * sin_phi + cos_phi_1 * cos_phi * cos(lambda - lambda_0) );
+
+	if (0 != c)
+		k_bar = c / sin(c);
+
+	/* using small angle approximation (formula in comment is without aproximation) */
+	*y = k_bar * (cos_phi * (lambda - lambda_0)) * scale;//*y = k_bar * (cos_phi * sin(lambda - lambda_0)) * scale;
+	*x = k_bar * ((cos_phi_1 * sin_phi - sin_phi_1 * cos_phi * (1 - pow((lambda - lambda_0), 2) / 2))) * scale; //	*x = k_bar * ((cos_phi_1 * sin_phi - sin_phi_1 * cos_phi * cos(lambda - lambda_0))) * scale;
+
+//	printf("%phi_1=%.10f, lambda_0 =%.10f\n", phi_1, lambda_0);
+}
+
+/**
+ * Transforms a point in the local azimuthal equidistant plane to the geographic coordinate system
+ *
+ * @param x north
+ * @param y east
+ * @param lat in degrees (47.1234567°, not 471234567°)
+ * @param lon in degrees (8.1234567°, not 81234567°)
+ */
+static void map_projection_reproject(float x, float y, double *lat, double *lon)
+{
+	/* notation and formulas accoring to: http://mathworld.wolfram.com/AzimuthalEquidistantProjection.html */
+
+	double x_descaled = x / scale;
+	double y_descaled = y / scale;
+
+	double c = sqrt(pow(x_descaled, 2) + pow(y_descaled, 2));
+	double sin_c = sin(c);
+	double cos_c = cos(c);
+
+	double lat_sphere = 0;
+
+	if (c != 0)
+		lat_sphere = asin(cos_c * sin_phi_1 + (x_descaled * sin_c * cos_phi_1) / c);
+	else
+		lat_sphere = asin(cos_c * sin_phi_1);
+
+//	printf("lat_sphere = %.10f\n",lat_sphere);
+
+	double lon_sphere = 0;
+
+	if (phi_1  == M_PI / 2) {
+		//using small angle approximation (formula in comment is without aproximation)
+		lon_sphere = (lambda_0 - y_descaled / x_descaled); //lon_sphere = (lambda_0 + atan2(-y_descaled, x_descaled));
+
+	} else if (phi_1 == -M_PI / 2) {
+		//using small angle approximation (formula in comment is without aproximation)
+		lon_sphere = (lambda_0 + y_descaled / x_descaled); //lon_sphere = (lambda_0 + atan2(y_descaled, x_descaled));
+
+	} else {
+
+		lon_sphere = (lambda_0 + atan2(y_descaled * sin_c , c * cos_phi_1 * cos_c - x_descaled * sin_phi_1 * sin_c));
+		//using small angle approximation
+//    	double denominator = (c * cos_phi_1 * cos_c - x_descaled * sin_phi_1 * sin_c);
+//    	if(denominator != 0)
+//    	{
+//    		lon_sphere = (lambda_0 + (y_descaled * sin_c) / denominator);
+//    	}
+//    	else
+//    	{
+//    	...
+//    	}
+	}
+
+//	printf("lon_sphere = %.10f\n",lon_sphere);
+
+	*lat = lat_sphere * 180.0 / M_PI;
+	*lon = lon_sphere * 180.0 / M_PI;
+
+}
+
+/****************************************************************************
+ * main
+ ****************************************************************************/
+
+int position_estimator_main(int argc, char *argv[])
+{
+
+	/* welcome user */
+	printf("[multirotor position_estimator] started\n");
+
+	/* initialize values */
+	static float u[2] = {0, 0};
+	static float z[3] = {0, 0, 0};
+	static float xapo[N_STATES] = {0, 0, 0, 0, 0, 0};
+	static float Papo[N_STATES * N_STATES] = {ERROR_COVARIANCE_INIT, 0, 0, 0, 0, 0,
+			ERROR_COVARIANCE_INIT, 0, 0, 0, 0, 0,
+			ERROR_COVARIANCE_INIT, 0, 0, 0, 0, 0,
+			ERROR_COVARIANCE_INIT, 0, 0, 0, 0, 0,
+			ERROR_COVARIANCE_INIT, 0, 0, 0, 0, 0,
+			ERROR_COVARIANCE_INIT, 0, 0, 0, 0, 0
+						 };
+
+	static float xapo1[N_STATES];
+	static float Papo1[36];
+
+	static float gps_covariance[3] = {0.0f, 0.0f, 0.0f};
+
+	static uint16_t counter = 0;
+	position_estimator_counter_position_information = 0;
+
+	uint8_t predict_only = 1;
+
+	bool gps_valid = false;
+
+	bool new_initialization = true;
+
+	static double lat_current = 0.0d;//[°]] --> 47.0
+	static double lon_current = 0.0d; //[°]] -->8.5
+	float alt_current = 0.0f;
+
+
+	//TODO: handle flight without gps but with estimator
+
+	/* subscribe to vehicle status, attitude, gps */
+	struct vehicle_gps_position_s gps;
+	gps.fix_type = 0;
+	struct vehicle_status_s vstatus;
+	struct vehicle_attitude_s att;
+
+	int vehicle_gps_sub = orb_subscribe(ORB_ID(vehicle_gps_position));
+	int vehicle_status_sub = orb_subscribe(ORB_ID(vehicle_status));
+
+	/* subscribe to attitude at 100 Hz */
+	int vehicle_attitude_sub = orb_subscribe(ORB_ID(vehicle_attitude));
+
+	/* wait until gps signal turns valid, only then can we initialize the projection */
+	while (gps.fix_type < 3) {
+		struct pollfd fds[1] = { {.fd = vehicle_gps_sub, .events = POLLIN} };
+
+		/* wait for GPS updates, BUT READ VEHICLE STATUS (!)
+		 * this choice is critical, since the vehicle status might not
+		 * actually change, if this app is started after GPS lock was
+		 * aquired.
+		 */
+		if (poll(fds, 1, 5000)) {
+			/* Wait for the GPS update to propagate (we have some time) */
+			usleep(5000);
+			/* Read wether the vehicle status changed */
+			orb_copy(ORB_ID(vehicle_gps_position), vehicle_gps_sub, &gps);
+			gps_valid = (gps.fix_type > 2);
+		}
+	}
+
+	/* get gps value for first initialization */
+	orb_copy(ORB_ID(vehicle_gps_position), vehicle_gps_sub, &gps);
+	lat_current = ((double)(gps.lat)) * 1e-7;
+	lon_current = ((double)(gps.lon)) * 1e-7;
+	alt_current = gps.alt * 1e-3;
+
+	/* initialize coordinates */
+	map_projection_init(lat_current, lon_current);
+
+	/* publish global position messages only after first GPS message */
+	struct vehicle_local_position_s local_pos = {
+		.x = 0,
+		.y = 0,
+		.z = 0
+	};
+	orb_advert_t local_pos_pub = orb_advertise(ORB_ID(vehicle_local_position), &local_pos);
+
+	printf("[multirotor position estimator] initialized projection with: lat: %.10f,  lon:%.10f\n", lat_current, lon_current);
+
+	while (1) {
+
+		/*This runs at the rate of the sensors, if we have also a new gps update this is used in the position_estimator function */
+		struct pollfd fds[1] = { {.fd = vehicle_attitude_sub, .events = POLLIN} };
+
+		if (poll(fds, 1, 5000) <= 0) {
+			/* error / timeout */
+		} else {
+
+			orb_copy(ORB_ID(vehicle_attitude), vehicle_attitude_sub, &att);
+			/* got attitude, updating pos as well */
+			orb_copy(ORB_ID(vehicle_gps_position), vehicle_gps_sub, &gps);
+			orb_copy(ORB_ID(vehicle_status), vehicle_status_sub, &vstatus);
+
+			/*copy attitude */
+			u[0] = att.roll;
+			u[1] = att.pitch;
+
+			/* initialize map projection with the last estimate (not at full rate) */
+			if (gps.fix_type > 2) {
+				/* Project gps lat lon (Geographic coordinate system) to plane*/
+				map_projection_project(((double)(gps.lat)) * 1e-7, ((double)(gps.lon)) * 1e-7, &(z[0]), &(z[1]));
+
+				local_pos.x = z[0];
+				local_pos.y = z[1];
+				/* negative offset from initialization altitude */
+				local_pos.z = alt_current - (gps.alt) * 1e-3;
+
+
+				orb_publish(ORB_ID(vehicle_local_position), local_pos_pub, &local_pos);
+			}
+
+
+			// 	gps_covariance[0] = gps.eph; //TODO: needs scaling
+			// 	gps_covariance[1] = gps.eph;
+			// 	gps_covariance[2] = gps.epv;
+
+			// } else {
+			// 	/* we can not use the gps signal (it is of low quality) */
+			// 	predict_only = 1;
+			// }
+
+			// //		predict_only = 0;																//TODO: only for testing, removeme, XXX
+			// //		z[0] = sinf(((float)counter)/180.0f*3.14159265f);								//TODO: only for testing, removeme, XXX
+			// //		usleep(100000);																	//TODO: only for testing, removeme, XXX
+
+
+			// /*Get new estimation (this is calculated in the plane) */
+			// //TODO: if new_initialization == true: use 0,0,0, else use xapo
+			// if (true == new_initialization) {																								//TODO,XXX: uncomment!
+			// 	xapo[0] = 0; //we have a new plane initialization. the current estimate is in the center of the plane
+			// 	xapo[2] = 0;
+			// 	xapo[4] = 0;
+			// 	position_estimator(u, z, xapo, Papo, gps_covariance, predict_only, xapo1, Papo1);
+
+			// } else {
+			// 	position_estimator(u, z, xapo, Papo, gps_covariance, predict_only, xapo1, Papo1);
+			// }
+
+
+
+			// /* Copy values from xapo1 to xapo */
+			// int i;
+
+			// for (i = 0; i < N_STATES; i++) {
+			// 	xapo[i] = xapo1[i];
+			// }
+
+			// if ((counter % REPROJECTION_COUNTER_LIMIT == 0) || (counter % (PROJECTION_INITIALIZE_COUNTER_LIMIT - 1) == 0)) {
+			// 	/* Reproject from plane to geographic coordinate system */
+			// 	//		map_projection_reproject(xapo1[0], xapo1[2], map_scale, phi_1, lambda_0, &lat_current, &lon_current) //TODO,XXX: uncomment!
+			// 	map_projection_reproject(z[0], z[1], &lat_current, &lon_current); //do not use estimator for projection testing, removeme
+			// 	//		//DEBUG
+			// 	//			if(counter%500 == 0)
+			// 	//			{
+			// 	//				printf("phi_1: %.10f\n", phi_1);
+			// 	//				printf("lambda_0: %.10f\n", lambda_0);
+			// 	//				printf("lat_estimated: %.10f\n", lat_current);
+			// 	//				printf("lon_estimated: %.10f\n", lon_current);
+			// 	//				printf("z[0]=%.10f, z[1]=%.10f, z[2]=%f\n", z[0], z[1], z[2]);
+			// 	//				fflush(stdout);
+			// 	//
+			// 	//			}
+
+			// 	//			if(!isnan(lat_current) && !isnan(lon_current))// && !isnan(xapo1[4]) && !isnan(xapo1[1]) && !isnan(xapo1[3]) && !isnan(xapo1[5]))
+			// 	//			{
+			// 	/* send out */
+
+			// 	global_pos.lat = lat_current;
+			// 	global_pos.lon = lon_current;
+			// 	global_pos.alt = xapo1[4];
+			// 	global_pos.vx = xapo1[1];
+			// 	global_pos.vy = xapo1[3];
+			// 	global_pos.vz = xapo1[5];
+
+				/* publish current estimate */
+				// orb_publish(ORB_ID(vehicle_global_position), global_pos_pub, &global_pos);
+				//			}
+				//			else
+				//			{
+				//				printf("[position estimator] ERROR: nan values, lat_current=%.4f, lon_current=%.4f, z[0]=%.4f z[1]=%.4f\n", lat_current, lon_current, z[0], z[1]);
+				//				fflush(stdout);
+				//			}
+
+			// }
+
+			counter++;
+		}
+
+	}
+
+	return 0;
+}
+
+