navigator: lot's of cleanup (WIP)

1 files changed, 307 insertions, 627 deletions

diff --git a/src/modules/navigator/navigator_main.cpp b/src/modules/navigator/navigator_main.cpp
index 494266dd3..34a28aec3 100644
--- a/src/modules/navigator/navigator_main.cpp
+++ b/src/modules/navigator/navigator_main.cpp
@@ -1,10 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2013, 2014 PX4 Development Team. All rights reserved.
- *   Author: @author Lorenz Meier <lm@inf.ethz.ch>
- *           @author Jean Cyr <jean.m.cyr@gmail.com>
- *           @author Julian Oes <joes@student.ethz.ch>
- *           @author Anton Babushkin <anton.babushkin@me.com>
+ *   Copyright (c) 2013-2014 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
@@ -35,19 +31,20 @@
  *
  ****************************************************************************/
 /**
- * @file navigator_main.c
+ * @file navigator_main.cpp
  * Implementation of the main navigation state machine.
  *
- * Handles missions, geo fencing and failsafe navigation behavior.
- * Published the mission item triplet for the position controller.
+ * Handles mission items, geo fencing and failsafe navigation behavior.
+ * Published the position setpoint triplet for the position controller.
  *
  * @author Lorenz Meier <lm@inf.ethz.ch>
  * @author Jean Cyr <jean.m.cyr@gmail.com>
- * @author Julian Oes <joes@student.ethz.ch>
+ * @author Julian Oes <julian@oes.ch>
  * @author Anton Babushkin <anton.babushkin@me.com>
  */
 
 #include <nuttx/config.h>
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -58,9 +55,13 @@
 #include <poll.h>
 #include <time.h>
 #include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
 #include <drivers/device/device.h>
 #include <drivers/drv_hrt.h>
 #include <arch/board/board.h>
+
 #include <uORB/uORB.h>
 #include <uORB/topics/vehicle_global_position.h>
 #include <uORB/topics/home_position.h>
@@ -71,20 +72,19 @@
 #include <uORB/topics/mission.h>
 #include <uORB/topics/fence.h>
 #include <uORB/topics/navigation_capabilities.h>
+
 #include <systemlib/param/param.h>
 #include <systemlib/err.h>
 #include <systemlib/state_table.h>
 #include <systemlib/perf_counter.h>
 #include <systemlib/systemlib.h>
 #include <geo/geo.h>
-#include <mathlib/mathlib.h>
 #include <dataman/dataman.h>
+#include <mathlib/mathlib.h>
 #include <mavlink/mavlink_log.h>
-#include <sys/types.h>
-#include <sys/stat.h>
 
-#include "navigator_state.h"
-#include "navigator_mission.h"
+#include "mission.h"
+#include "rtl.h"
 #include "mission_feasibility_checker.h"
 #include "geofence.h"
 
@@ -130,12 +130,12 @@ public:
 	/**
 	 * Add point to geofence
 	 */
-	void add_fence_point(int argc, char *argv[]);
+	void		add_fence_point(int argc, char *argv[]);
 
 	/**
 	 * Load fence from file
 	 */
-	void load_fence_from_file(const char *filename);
+	void		load_fence_from_file(const char *filename);
 
 private:
 
@@ -154,15 +154,15 @@ private:
 	int		_control_mode_sub;		/**< vehicle control mode subscription */
 
 	orb_advert_t	_pos_sp_triplet_pub;		/**< publish position setpoint triplet */
-	orb_advert_t	_mission_result_pub;		/**< publish mission result topic */
 
-	struct vehicle_status_s				_vstatus;		/**< vehicle status */
-	struct vehicle_control_mode_s			_control_mode;		/**< vehicle control mode */
-	struct vehicle_global_position_s		_global_pos;		/**< global vehicle position */
-	struct home_position_s				_home_pos;		/**< home position for RTL */
-	struct position_setpoint_triplet_s		_pos_sp_triplet;	/**< triplet of position setpoints */
-	struct mission_result_s				_mission_result;	/**< mission result for commander/mavlink */
-	struct mission_item_s				_mission_item;		/**< current mission item */
+	vehicle_status_s				_vstatus;		/**< vehicle status */
+	vehicle_control_mode_s				_control_mode;		/**< vehicle control mode */
+	vehicle_global_position_s			_global_pos;		/**< global vehicle position */
+	home_position_s					_home_pos;		/**< home position for RTL */
+	position_setpoint_triplet_s			_pos_sp_triplet;	/**< triplet of position setpoints */
+	mission_item_s 					_mission_item;		/**< current mission item */
+
+	bool 						_mission_item_valid;
 
 	perf_counter_t	_loop_perf;			/**< loop performance counter */
 
@@ -174,56 +174,41 @@ private:
 
 	struct navigation_capabilities_s		_nav_caps;
 
-	class 		Mission				_mission;
+	Mission						_mission;
+
+	RTL 						_rtl;
 
-	bool		_mission_item_valid;		/**< current mission item valid */
-	bool		_global_pos_valid;		/**< track changes of global_position.global_valid flag */
-	bool		_reset_loiter_pos;		/**< if true then loiter position should be set to current position */
 	bool		_waypoint_position_reached;
 	bool		_waypoint_yaw_reached;
 	uint64_t	_time_first_inside_orbit;
-	bool		_need_takeoff;			/**< if need to perform vertical takeoff before going to waypoint (only for MISSION mode and VTOL vehicles) */
-	bool		_do_takeoff;			/**< vertical takeoff state, current mission item is generated by navigator (only for MISSION mode and VTOL vehicles) */
-
 	MissionFeasibilityChecker missionFeasiblityChecker;
 
-	uint64_t	_set_nav_state_timestamp;	/**< timestamp of last handled navigation state request */
-
-	bool		_pos_sp_triplet_updated;
-
-	const char *nav_states_str[NAV_STATE_MAX];
+	bool		_update_triplet;
 
 	struct {
-		float min_altitude;
 		float acceptance_radius;
 		float loiter_radius;
 		int onboard_mission_enabled;
 		float takeoff_alt;
-		float land_alt;
-		float rtl_alt;
-		float rtl_land_delay;
 	}		_parameters;			/**< local copies of parameters */
 
 	struct {
-		param_t min_altitude;
 		param_t acceptance_radius;
 		param_t loiter_radius;
 		param_t onboard_mission_enabled;
 		param_t takeoff_alt;
-		param_t land_alt;
-		param_t rtl_alt;
-		param_t rtl_land_delay;
 	}		_parameter_handles;		/**< handles for parameters */
 
 	enum Event {
 		EVENT_NONE_REQUESTED,
-		EVENT_READY_REQUESTED,
 		EVENT_LOITER_REQUESTED,
 		EVENT_MISSION_REQUESTED,
 		EVENT_RTL_REQUESTED,
-		EVENT_LAND_REQUESTED,
+		EVENT_TAKEN_OFF,
+		EVENT_LANDED,
 		EVENT_MISSION_CHANGED,
 		EVENT_HOME_POSITION_CHANGED,
+		EVENT_MISSION_ITEM_REACHED,
 		MAX_EVENT
 	};
 
@@ -232,15 +217,6 @@ private:
 	 */
 	static StateTable::Tran const myTable[NAV_STATE_MAX][MAX_EVENT];
 
-	enum RTLState {
-		RTL_STATE_NONE = 0,
-		RTL_STATE_CLIMB,
-		RTL_STATE_RETURN,
-		RTL_STATE_DESCEND
-	};
-
-	enum RTLState _rtl_state;
-
 	/**
 	 * Update our local parameter cache.
 	 */
@@ -264,7 +240,7 @@ private:
 	/**
 	 * Retrieve offboard mission.
 	 */
-	void		offboard_mission_update(bool isrotaryWing);
+	void		offboard_mission_update();
 
 	/**
 	 * Retrieve onboard mission.
@@ -296,19 +272,20 @@ private:
 	/**
 	 * Functions that are triggered when a new state is entered.
 	 */
-	void		start_none();
-	void		start_ready();
-	void		start_loiter();
-	void		start_mission();
-	void		start_rtl();
-	void		start_land();
-	void		start_land_home();
+	bool		start_none_on_ground();
+	bool		start_none_in_air();
+	bool		start_auto_on_ground();
+	bool		start_loiter();
+	bool		start_mission();
+	bool		advance_mission();
+	bool		start_rtl();
+	bool		advance_rtl();
+	bool		start_land();
 
 	/**
 	 * Fork for state transitions
 	 */
-	void		request_loiter_or_ready();
-	void		request_mission_if_available();
+	// void		request_loiter_or_ready();
 
 	/**
 	 * Guards offboard mission
@@ -333,12 +310,12 @@ private:
 	/**
 	 * Perform actions when current mission item reached.
 	 */
-	void		on_mission_item_reached();
+	// void		on_mission_item_reached();
 
 	/**
 	 * Move to next waypoint
 	 */
-	void		set_mission_item();
+	bool		set_mission_items();
 
 	/**
 	 * Switch to next RTL state
@@ -348,7 +325,7 @@ private:
 	/**
 	 * Set position setpoint for mission item
 	 */
-	void		position_setpoint_from_mission_item(position_setpoint_s *sp, mission_item_s *item);
+	void		mission_item_to_position_setpoint(const mission_item_s *item, position_setpoint_s *sp);
 
 	/**
 	 * Helper function to get a takeoff item
@@ -377,12 +354,9 @@ Navigator::Navigator() :
 
 /* state machine transition table */
 	StateTable(&myTable[0][0], NAV_STATE_MAX, MAX_EVENT),
-
 	_task_should_exit(false),
 	_navigator_task(-1),
 	_mavlink_fd(-1),
-
-/* subscriptions */
 	_global_pos_sub(-1),
 	_home_pos_sub(-1),
 	_vstatus_sub(-1),
@@ -391,53 +365,29 @@ Navigator::Navigator() :
 	_onboard_mission_sub(-1),
 	_capabilities_sub(-1),
 	_control_mode_sub(-1),
-
-/* publications */
 	_pos_sp_triplet_pub(-1),
-
-/* performance counters */
 	_loop_perf(perf_alloc(PC_ELAPSED, "navigator")),
-
 	_geofence_violation_warning_sent(false),
 	_fence_valid(false),
 	_inside_fence(true),
 	_mission(),
+	_pos_sp_triplet({}),
+	_mission_item({}),
 	_mission_item_valid(false),
-	_global_pos_valid(false),
-	_reset_loiter_pos(true),
 	_waypoint_position_reached(false),
 	_waypoint_yaw_reached(false),
 	_time_first_inside_orbit(0),
-	_need_takeoff(true),
-	_do_takeoff(false),
-	_set_nav_state_timestamp(0),
-	_pos_sp_triplet_updated(false),
-/* states */
-	_rtl_state(RTL_STATE_NONE)
+	_update_triplet(false)
 {
-	_parameter_handles.min_altitude = param_find("NAV_MIN_ALT");
 	_parameter_handles.acceptance_radius = param_find("NAV_ACCEPT_RAD");
 	_parameter_handles.loiter_radius = param_find("NAV_LOITER_RAD");
 	_parameter_handles.onboard_mission_enabled = param_find("NAV_ONB_MIS_EN");
 	_parameter_handles.takeoff_alt = param_find("NAV_TAKEOFF_ALT");
-	_parameter_handles.land_alt = param_find("NAV_LAND_ALT");
-	_parameter_handles.rtl_alt = param_find("NAV_RTL_ALT");
-	_parameter_handles.rtl_land_delay = param_find("NAV_RTL_LAND_T");
-
-	memset(&_pos_sp_triplet, 0, sizeof(struct position_setpoint_triplet_s));
-	memset(&_mission_item, 0, sizeof(struct mission_item_s));
-
-	memset(&nav_states_str, 0, sizeof(nav_states_str));
-	nav_states_str[0] = "NONE";
-	nav_states_str[1] = "READY";
-	nav_states_str[2] = "LOITER";
-	nav_states_str[3] = "MISSION";
-	nav_states_str[4] = "RTL";
-	nav_states_str[5] = "LAND";
 
 	/* Initialize state machine */
-	myState = NAV_STATE_NONE;
-	start_none();
+	myState = NAV_STATE_NONE_ON_GROUND;
+
+	start_none_on_ground();
 }
 
 Navigator::~Navigator()
@@ -472,16 +422,12 @@ Navigator::parameters_update()
 	struct parameter_update_s update;
 	orb_copy(ORB_ID(parameter_update), _params_sub, &update);
 
-	param_get(_parameter_handles.min_altitude, &(_parameters.min_altitude));
 	param_get(_parameter_handles.acceptance_radius, &(_parameters.acceptance_radius));
 	param_get(_parameter_handles.loiter_radius, &(_parameters.loiter_radius));
 	param_get(_parameter_handles.onboard_mission_enabled, &(_parameters.onboard_mission_enabled));
-	param_get(_parameter_handles.takeoff_alt, &(_parameters.takeoff_alt));
-	param_get(_parameter_handles.land_alt, &(_parameters.land_alt));
-	param_get(_parameter_handles.rtl_alt, &(_parameters.rtl_alt));
-	param_get(_parameter_handles.rtl_land_delay, &(_parameters.rtl_land_delay));
+	param_get(_parameter_handles.takeoff_alt, &(_parameters.takeoff_alt));	
 
-	_mission.set_onboard_mission_allowed((bool)_parameter_handles.onboard_mission_enabled);
+	_mission.set_onboard_mission_allowed((bool)_parameters.onboard_mission_enabled);
 
 	_geofence.updateParams();
 }
@@ -496,6 +442,8 @@ void
 Navigator::home_position_update()
 {
 	orb_copy(ORB_ID(home_position), _home_pos_sub, &_home_pos);
+
+	_rtl.set_home_position(&_home_pos);
 }
 
 void
@@ -506,7 +454,7 @@ Navigator::navigation_capabilities_update()
 
 
 void
-Navigator::offboard_mission_update(bool isrotaryWing)
+Navigator::offboard_mission_update()
 {
 	struct mission_s offboard_mission;
 
@@ -523,19 +471,17 @@ Navigator::offboard_mission_update(bool isrotaryWing)
 			dm_current = DM_KEY_WAYPOINTS_OFFBOARD_1;
 		}
 
-		missionFeasiblityChecker.checkMissionFeasible(isrotaryWing, dm_current, (size_t)offboard_mission.count, _geofence);
+		missionFeasiblityChecker.checkMissionFeasible(_vstatus.is_rotary_wing, dm_current, (size_t)offboard_mission.count, _geofence);
 
 		_mission.set_offboard_dataman_id(offboard_mission.dataman_id);
 
 		_mission.set_offboard_mission_count(offboard_mission.count);
-		_mission.set_current_offboard_mission_index(offboard_mission.current_index);
+		_mission.command_current_offboard_mission_index(offboard_mission.current_index);
 
 	} else {
 		_mission.set_offboard_mission_count(0);
-		_mission.set_current_offboard_mission_index(0);
+		_mission.command_current_offboard_mission_index(0);
 	}
-
-	_mission.publish_mission_result();
 }
 
 void
@@ -546,11 +492,11 @@ Navigator::onboard_mission_update()
 	if (orb_copy(ORB_ID(onboard_mission), _onboard_mission_sub, &onboard_mission) == OK) {
 
 		_mission.set_onboard_mission_count(onboard_mission.count);
-		_mission.set_current_onboard_mission_index(onboard_mission.current_index);
+		_mission.command_current_onboard_mission_index(onboard_mission.current_index);
 
 	} else {
 		_mission.set_onboard_mission_count(0);
-		_mission.set_current_onboard_mission_index(0);
+		_mission.command_current_onboard_mission_index(0);
 	}
 }
 
@@ -626,13 +572,13 @@ Navigator::task_main()
 	global_position_update();
 	home_position_update();
 	navigation_capabilities_update();
-	offboard_mission_update(_vstatus.is_rotary_wing);
+	offboard_mission_update();
 	onboard_mission_update();
 
 	/* rate limit position updates to 50 Hz */
 	orb_set_interval(_global_pos_sub, 20);
 
-	unsigned prevState = NAV_STATE_NONE;
+	unsigned prevState = NAV_STATE_NONE_ON_GROUND;
 	hrt_abstime mavlink_open_time = 0;
 	const hrt_abstime mavlink_open_interval = 500000;
 
@@ -690,55 +636,45 @@ Navigator::task_main()
 		if (fds[6].revents & POLLIN) {
 			vehicle_status_update();
 
-			/* evaluate state requested by commander */
-			if (_control_mode.flag_armed && _control_mode.flag_control_auto_enabled) {
-				if (_vstatus.set_nav_state_timestamp != _set_nav_state_timestamp) {
-					/* commander requested new navigation mode, try to set it */
-					switch (_vstatus.set_nav_state) {
-					case NAV_STATE_NONE:
-						/* nothing to do */
-						break;
-
-					case NAV_STATE_LOITER:
-						request_loiter_or_ready();
-						break;
-
-					case NAV_STATE_MISSION:
-						request_mission_if_available();
-						break;
-
-					case NAV_STATE_RTL:
-						if (!(_rtl_state == RTL_STATE_DESCEND &&
-							  (myState == NAV_STATE_LAND || myState == NAV_STATE_LOITER)) &&
-							_vstatus.condition_home_position_valid) {
-							dispatch(EVENT_RTL_REQUESTED);
-						}
-
-						break;
-
-					case NAV_STATE_LAND:
-						dispatch(EVENT_LAND_REQUESTED);
-
-						break;
-
-					default:
-						warnx("ERROR: Requested navigation state not supported");
-						break;
-					}
-
-				} else {
-					/* on first switch to AUTO try mission by default, if none is available fallback to loiter */
-					if (myState == NAV_STATE_NONE) {
-						request_mission_if_available();
-					}
-				}
-
-			} else {
-				/* navigator shouldn't act */
+			/* commander requested new navigation mode, forward it to state machine */
+			switch (_vstatus.set_nav_state) {
+			case NAVIGATION_STATE_NONE:
 				dispatch(EVENT_NONE_REQUESTED);
+				break;
+
+			case NAVIGATION_STATE_LOITER:
+				dispatch(EVENT_LOITER_REQUESTED);
+				break;
+
+			case NAVIGATION_STATE_MISSION:
+				dispatch(EVENT_MISSION_REQUESTED);
+				break;
+
+			case NAVIGATION_STATE_RTL:
+				/* TODO: what is this for? */
+				// if (!(_rtl_state == RTL_STATE_DESCEND &&
+				// 	  (myState == NAV_STATE_LAND || myState == NAV_STATE_LOITER)) &&
+				// 	_vstatus.condition_home_position_valid) {
+				dispatch(EVENT_RTL_REQUESTED);
+				// }
+				break;
+
+			case NAVIGATION_STATE_LAND:
+				/* TODO: add this */
+				// dispatch(EVENT_LAND_REQUESTED);
+				break;
+
+			default:
+				warnx("ERROR: Requested navigation state not supported");
+				break;
 			}
 
-			_set_nav_state_timestamp = _vstatus.set_nav_state_timestamp;
+			/* commander sets in-air/on-ground flag as well */
+			if (_vstatus.condition_landed) {
+				dispatch(EVENT_LANDED);
+			} else {
+				dispatch(EVENT_TAKEN_OFF);
+			}
 		}
 
 		/* parameters updated */
@@ -754,74 +690,49 @@ Navigator::task_main()
 
 		/* offboard mission updated */
 		if (fds[4].revents & POLLIN) {
-			offboard_mission_update(_vstatus.is_rotary_wing);
-			// XXX check if mission really changed
+			offboard_mission_update();
+			/* TODO: check if mission really changed */
 			dispatch(EVENT_MISSION_CHANGED);
 		}
 
 		/* onboard mission updated */
 		if (fds[5].revents & POLLIN) {
 			onboard_mission_update();
-			// XXX check if mission really changed
+			/* TODO: check if mission really changed */
 			dispatch(EVENT_MISSION_CHANGED);
 		}
 
 		/* home position updated */
 		if (fds[2].revents & POLLIN) {
 			home_position_update();
-			// XXX check if home position really changed
+			/* TODO check if home position really changed */
 			dispatch(EVENT_HOME_POSITION_CHANGED);
 		}
 
 		/* global position updated */
 		if (fds[1].revents & POLLIN) {
 			global_position_update();
-
-			/* publish position setpoint triplet on each position update if navigator active */
-			if (_control_mode.flag_armed && _control_mode.flag_control_auto_enabled) {
-				_pos_sp_triplet_updated = true;
-
-				if (myState == NAV_STATE_LAND && _global_pos.global_valid && !_global_pos_valid) {
-					/* got global position when landing, update setpoint */
-					start_land();
-				}
-
-				_global_pos_valid = _global_pos.global_valid;
-
-				/* check if waypoint has been reached in MISSION, RTL and LAND modes */
-				if (myState == NAV_STATE_MISSION || myState == NAV_STATE_RTL || myState == NAV_STATE_LAND) {
-					if (check_mission_item_reached()) {
-						on_mission_item_reached();
-					}
-				}
+			if (check_mission_item_reached()) {
+				dispatch(EVENT_MISSION_ITEM_REACHED);
 			}
 
 			/* Check geofence violation */
 			if (!_geofence.inside(&_global_pos)) {
-				//xxx: publish geofence violation here (or change local flag depending on which app handles the flight termination)
 
 				/* Issue a warning about the geofence violation once */
 				if (!_geofence_violation_warning_sent) {
 					mavlink_log_critical(_mavlink_fd, "#audio: Geofence violation");
 					_geofence_violation_warning_sent = true;
 				}
-
 			} else {
 				/* Reset the _geofence_violation_warning_sent field */
 				_geofence_violation_warning_sent = false;
 			}
 		}
 
-		/* publish position setpoint triplet if updated */
-		if (_pos_sp_triplet_updated) {
-			_pos_sp_triplet_updated = false;
+		if (_update_triplet ) {
 			publish_position_setpoint_triplet();
-		}
-
-		/* notify user about state changes */
-		if (myState != prevState) {
-			mavlink_log_info(_mavlink_fd, "#audio: navigation state: %s", nav_states_str[myState]);
-			prevState = myState;
+			_update_triplet = false;
 		}
 
 		perf_end(_loop_perf);
@@ -879,8 +790,12 @@ Navigator::status()
 	}
 
 	switch (myState) {
-	case NAV_STATE_NONE:
-		warnx("State: None");
+	case NAV_STATE_NONE_ON_GROUND:
+		warnx("State: None on ground");
+		break;
+
+	case NAV_STATE_NONE_IN_AIR:
+		warnx("State: None in air");
 		break;
 
 	case NAV_STATE_LOITER:
@@ -895,6 +810,10 @@ Navigator::status()
 		warnx("State: RTL");
 		break;
 
+	case NAV_STATE_LAND:
+		warnx("State: LAND");
+		break;
+
 	default:
 		warnx("State: Unknown");
 		break;
@@ -903,92 +822,119 @@ Navigator::status()
 
 StateTable::Tran const Navigator::myTable[NAV_STATE_MAX][MAX_EVENT] = {
 	{
-		/* NAV_STATE_NONE */
-		/* EVENT_NONE_REQUESTED */		{NO_ACTION, NAV_STATE_NONE},
-		/* EVENT_READY_REQUESTED */		{ACTION(&Navigator::start_ready), NAV_STATE_READY},
+		/* NAV_STATE_NONE_ON_GROUND */
+		/* EVENT_NONE_REQUESTED */		{NO_ACTION, NAV_STATE_NONE_ON_GROUND},
+		/* EVENT_LOITER_REQUESTED */		{NO_ACTION, NAV_STATE_NONE_ON_GROUND},
+		/* EVENT_MISSION_REQUESTED */		{ACTION(&Navigator::start_auto_on_ground), NAV_STATE_AUTO_ON_GROUND},
+		/* EVENT_RTL_REQUESTED */		{NO_ACTION, NAV_STATE_NONE_ON_GROUND},
+		/* EVENT_TAKEN_OFF */			{ACTION(&Navigator::start_none_in_air), NAV_STATE_NONE_IN_AIR},
+		/* EVENT_LANDED */			{NO_ACTION, NAV_STATE_NONE_ON_GROUND},
+		/* EVENT_MISSION_CHANGED */		{NO_ACTION, NAV_STATE_NONE_ON_GROUND},
+		/* EVENT_HOME_POSITION_CHANGED */	{NO_ACTION, NAV_STATE_NONE_ON_GROUND},
+		/* EVENT_MISSION_ITEM_REACHED */	{NO_ACTION, NAV_STATE_NONE_ON_GROUND},
+	},
+	{
+		/* NAV_STATE_NONE_IN_AIR */
+		/* EVENT_NONE_REQUESTED */		{NO_ACTION, NAV_STATE_NONE_IN_AIR},
 		/* EVENT_LOITER_REQUESTED */		{ACTION(&Navigator::start_loiter), NAV_STATE_LOITER},
 		/* EVENT_MISSION_REQUESTED */		{ACTION(&Navigator::start_mission), NAV_STATE_MISSION},
 		/* EVENT_RTL_REQUESTED */		{ACTION(&Navigator::start_rtl), NAV_STATE_RTL},
-		/* EVENT_LAND_REQUESTED */		{ACTION(&Navigator::start_land), NAV_STATE_LAND},
-		/* EVENT_MISSION_CHANGED */		{NO_ACTION, NAV_STATE_NONE},
-		/* EVENT_HOME_POSITION_CHANGED */	{NO_ACTION, NAV_STATE_NONE},
+		/* EVENT_TAKEN_OFF */			{NO_ACTION, NAV_STATE_NONE_IN_AIR},
+		/* EVENT_LANDED */			{ACTION(&Navigator::start_none_on_ground), NAV_STATE_NONE_ON_GROUND},
+		/* EVENT_MISSION_CHANGED */		{NO_ACTION, NAV_STATE_NONE_IN_AIR},
+		/* EVENT_HOME_POSITION_CHANGED */	{NO_ACTION, NAV_STATE_NONE_IN_AIR},
+		/* EVENT_MISSION_ITEM_REACHED */	{NO_ACTION, NAV_STATE_NONE_IN_AIR},
 	},
 	{
-		/* NAV_STATE_READY */
-		/* EVENT_NONE_REQUESTED */		{ACTION(&Navigator::start_none), NAV_STATE_NONE},
-		/* EVENT_READY_REQUESTED */		{NO_ACTION, NAV_STATE_READY},
-		/* EVENT_LOITER_REQUESTED */		{NO_ACTION, NAV_STATE_READY},
-		/* EVENT_MISSION_REQUESTED */		{ACTION(&Navigator::start_mission), NAV_STATE_MISSION},
-		/* EVENT_RTL_REQUESTED */		{NO_ACTION, NAV_STATE_READY},
-		/* EVENT_LAND_REQUESTED */		{NO_ACTION, NAV_STATE_READY},
-		/* EVENT_MISSION_CHANGED */		{NO_ACTION, NAV_STATE_READY},
-		/* EVENT_HOME_POSITION_CHANGED */	{NO_ACTION, NAV_STATE_READY},
+		/* NAV_STATE_AUTO_ON_GROUND */
+		/* EVENT_NONE_REQUESTED */		{NO_ACTION, NAV_STATE_AUTO_ON_GROUND},
+		/* EVENT_LOITER_REQUESTED */		{NO_ACTION, NAV_STATE_AUTO_ON_GROUND},
+		/* EVENT_MISSION_REQUESTED */		{NO_ACTION, NAV_STATE_AUTO_ON_GROUND},
+		/* EVENT_RTL_REQUESTED */		{NO_ACTION, NAV_STATE_AUTO_ON_GROUND},
+		/* EVENT_TAKEN_OFF */			{ACTION(&Navigator::start_mission), NAV_STATE_MISSION},
+		/* EVENT_LANDED */			{NO_ACTION, NAV_STATE_AUTO_ON_GROUND},
+		/* EVENT_MISSION_CHANGED */		{NO_ACTION, NAV_STATE_AUTO_ON_GROUND},
+		/* EVENT_HOME_POSITION_CHANGED */	{NO_ACTION, NAV_STATE_AUTO_ON_GROUND},
+		/* EVENT_MISSION_ITEM_REACHED */	{NO_ACTION, NAV_STATE_AUTO_ON_GROUND},
 	},
 	{
 		/* NAV_STATE_LOITER */
-		/* EVENT_NONE_REQUESTED */		{ACTION(&Navigator::start_none), NAV_STATE_NONE},
-		/* EVENT_READY_REQUESTED */		{NO_ACTION, NAV_STATE_LOITER},
+		/* EVENT_NONE_REQUESTED */		{ACTION(&Navigator::start_none_in_air), NAV_STATE_NONE_IN_AIR},
 		/* EVENT_LOITER_REQUESTED */		{NO_ACTION, NAV_STATE_LOITER},
 		/* EVENT_MISSION_REQUESTED */		{ACTION(&Navigator::start_mission), NAV_STATE_MISSION},
 		/* EVENT_RTL_REQUESTED */		{ACTION(&Navigator::start_rtl), NAV_STATE_RTL},
-		/* EVENT_LAND_REQUESTED */		{ACTION(&Navigator::start_land), NAV_STATE_LAND},
+		/* EVENT_TAKEN_OFF */			{NO_ACTION, NAV_STATE_LOITER},
+		/* EVENT_LANDED */			{NO_ACTION, NAV_STATE_LOITER},
 		/* EVENT_MISSION_CHANGED */		{NO_ACTION, NAV_STATE_LOITER},
 		/* EVENT_HOME_POSITION_CHANGED */	{NO_ACTION, NAV_STATE_LOITER},
+		/* EVENT_MISSION_ITEM_REACHED */	{NO_ACTION, NAV_STATE_LOITER},
 	},
 	{
 		/* NAV_STATE_MISSION */
-		/* EVENT_NONE_REQUESTED */		{ACTION(&Navigator::start_none), NAV_STATE_NONE},
-		/* EVENT_READY_REQUESTED */		{ACTION(&Navigator::start_ready), NAV_STATE_READY},
+		/* EVENT_NONE_REQUESTED */		{ACTION(&Navigator::start_none_in_air), NAV_STATE_NONE_IN_AIR},
 		/* EVENT_LOITER_REQUESTED */		{ACTION(&Navigator::start_loiter), NAV_STATE_LOITER},
 		/* EVENT_MISSION_REQUESTED */		{NO_ACTION, NAV_STATE_MISSION},
 		/* EVENT_RTL_REQUESTED */		{ACTION(&Navigator::start_rtl), NAV_STATE_RTL},
-		/* EVENT_LAND_REQUESTED */		{ACTION(&Navigator::start_land), NAV_STATE_LAND},
+		/* EVENT_TAKEN_OFF */			{NO_ACTION, NAV_STATE_MISSION},
+		/* EVENT_LANDED */			{NO_ACTION, NAV_STATE_MISSION},
 		/* EVENT_MISSION_CHANGED */		{ACTION(&Navigator::start_mission), NAV_STATE_MISSION},
 		/* EVENT_HOME_POSITION_CHANGED */	{NO_ACTION, NAV_STATE_MISSION},
+		/* EVENT_MISSION_ITEM_REACHED */	{ACTION(&Navigator::advance_mission), NAV_STATE_MISSION},
 	},
 	{
 		/* NAV_STATE_RTL */
-		/* EVENT_NONE_REQUESTED */		{ACTION(&Navigator::start_none), NAV_STATE_NONE},
-		/* EVENT_READY_REQUESTED */		{ACTION(&Navigator::start_ready), NAV_STATE_READY},
+		/* EVENT_NONE_REQUESTED */		{ACTION(&Navigator::start_none_in_air), NAV_STATE_NONE_IN_AIR},
 		/* EVENT_LOITER_REQUESTED */		{ACTION(&Navigator::start_loiter), NAV_STATE_LOITER},
 		/* EVENT_MISSION_REQUESTED */		{ACTION(&Navigator::start_mission), NAV_STATE_MISSION},
 		/* EVENT_RTL_REQUESTED */		{NO_ACTION, NAV_STATE_RTL},
-		/* EVENT_LAND_REQUESTED */		{ACTION(&Navigator::start_land_home), NAV_STATE_LAND},
+		/* EVENT_TAKEN_OFF */			{NO_ACTION, NAV_STATE_RTL},
+		/* EVENT_LANDED */			{NO_ACTION, NAV_STATE_RTL},
 		/* EVENT_MISSION_CHANGED */		{NO_ACTION, NAV_STATE_RTL},
-		/* EVENT_HOME_POSITION_CHANGED */	{ACTION(&Navigator::start_rtl), NAV_STATE_RTL},	// TODO need to reset rtl_state
+		/* EVENT_HOME_POSITION_CHANGED */	{ACTION(&Navigator::start_rtl), NAV_STATE_RTL},
+		/* EVENT_MISSION_ITEM_REACHED */	{ACTION(&Navigator::advance_rtl), NAV_STATE_RTL},
 	},
 	{
 		/* NAV_STATE_LAND */
-		/* EVENT_NONE_REQUESTED */		{ACTION(&Navigator::start_none), NAV_STATE_NONE},
-		/* EVENT_READY_REQUESTED */		{ACTION(&Navigator::start_ready), NAV_STATE_READY},
+		/* EVENT_NONE_REQUESTED */		{ACTION(&Navigator::start_none_in_air), NAV_STATE_NONE_IN_AIR},
 		/* EVENT_LOITER_REQUESTED */		{ACTION(&Navigator::start_loiter), NAV_STATE_LOITER},
 		/* EVENT_MISSION_REQUESTED */		{ACTION(&Navigator::start_mission), NAV_STATE_MISSION},
 		/* EVENT_RTL_REQUESTED */		{ACTION(&Navigator::start_rtl), NAV_STATE_RTL},
-		/* EVENT_LAND_REQUESTED */		{NO_ACTION, NAV_STATE_LAND},
+		/* EVENT_TAKEN_OFF */			{NO_ACTION, NAV_STATE_LAND},
+		/* EVENT_LANDED */			{ACTION(&Navigator::start_auto_on_ground), NAV_STATE_AUTO_ON_GROUND},
 		/* EVENT_MISSION_CHANGED */		{NO_ACTION, NAV_STATE_LAND},
 		/* EVENT_HOME_POSITION_CHANGED */	{NO_ACTION, NAV_STATE_LAND},
+		/* EVENT_MISSION_ITEM_REACHED */	{NO_ACTION, NAV_STATE_LAND},
 	},
 };
 
-void
-Navigator::start_none()
+bool
+Navigator::start_none_on_ground()
 {
 	reset_reached();
 
 	_pos_sp_triplet.previous.valid = false;
 	_pos_sp_triplet.current.valid = false;
 	_pos_sp_triplet.next.valid = false;
-	_mission_item_valid = false;
 
-	_reset_loiter_pos = true;
-	_do_takeoff = false;
-	_rtl_state = RTL_STATE_NONE;
+	_update_triplet = true;
+	return true;
+}
+
+bool
+Navigator::start_none_in_air()
+{
+	reset_reached();
+
+	_pos_sp_triplet.previous.valid = false;
+	_pos_sp_triplet.current.valid = false;
+	_pos_sp_triplet.next.valid = false;
 
-	_pos_sp_triplet_updated = true;
+	_update_triplet = true;
+	return true;
 }
 
-void
-Navigator::start_ready()
+bool
+Navigator::start_auto_on_ground()
 {
 	reset_reached();
 
@@ -998,46 +944,26 @@ Navigator::start_ready()
 
 	_pos_sp_triplet.current.type = SETPOINT_TYPE_IDLE;
 
-	_mission_item_valid = false;
-
-	_reset_loiter_pos = true;
-	_do_takeoff = false;
 
-	if (_rtl_state != RTL_STATE_DESCEND) {
-		/* reset RTL state if landed not at home */
-		_rtl_state = RTL_STATE_NONE;
-	}
+	// if (_rtl_state != RTL_STATE_DESCEND) {
+	// 	 reset RTL state if landed not at home 
+	// 	_rtl_state = RTL_STATE_NONE;
+	// }
 
-	_pos_sp_triplet_updated = true;
+	_update_triplet = true;
+	return true;
 }
 
-void
+bool
 Navigator::start_loiter()
 {
-	reset_reached();
-
-	_do_takeoff = false;
-
-	/* set loiter position if needed */
-	if (_reset_loiter_pos || !_pos_sp_triplet.current.valid) {
-		_reset_loiter_pos = false;
+	/* if no existing item available, use current position */
+	if (!(_pos_sp_triplet.current.valid && _waypoint_position_reached)) {
 
 		_pos_sp_triplet.current.lat = _global_pos.lat;
 		_pos_sp_triplet.current.lon = _global_pos.lon;
 		_pos_sp_triplet.current.yaw = NAN;	// NAN means to use current yaw
-
-		float min_alt_amsl = _parameters.min_altitude + _home_pos.alt;
-
-		/* use current altitude if above min altitude set by parameter */
-		if (_global_pos.alt < min_alt_amsl && !_vstatus.is_rotary_wing) {
-			_pos_sp_triplet.current.alt = min_alt_amsl;
-			mavlink_log_info(_mavlink_fd, "#audio: loiter %.1fm higher", (double)(min_alt_amsl - _global_pos.alt));
-
-		} else {
-			_pos_sp_triplet.current.alt = _global_pos.alt;
-			mavlink_log_info(_mavlink_fd, "#audio: loiter at current altitude");
-		}
-
+		_pos_sp_triplet.current.alt = _global_pos.alt;
 	}
 	_pos_sp_triplet.current.type = SETPOINT_TYPE_LOITER;
 	_pos_sp_triplet.current.loiter_radius = _parameters.loiter_radius;
@@ -1045,167 +971,146 @@ Navigator::start_loiter()
 	_pos_sp_triplet.previous.valid = false;
 	_pos_sp_triplet.current.valid = true;
 	_pos_sp_triplet.next.valid = false;
-	_mission_item_valid = false;
 
-	_pos_sp_triplet_updated = true;
+	mavlink_log_info(_mavlink_fd, "#audio: loiter at current altitude");
+
+	_update_triplet = true;
+	return true;	
 }
 
-void
+bool
 Navigator::start_mission()
 {
-	_need_takeoff = true;
+	/* start fresh */
+	_pos_sp_triplet.previous.valid = false;
+	_pos_sp_triplet.current.valid = false;
+	_pos_sp_triplet.next.valid = false;
 
-	set_mission_item();
+	return set_mission_items();
 }
 
-void
-Navigator::set_mission_item()
+bool
+Navigator::advance_mission()
 {
-	reset_reached();
+	/* tell mission to move by one */
+	_mission.move_to_next();
 
-	/* copy current mission to previous item */
-	memcpy(&_pos_sp_triplet.previous, &_pos_sp_triplet.current, sizeof(position_setpoint_s));
+	/* now try to set the new mission items, if it fails, it will dispatch loiter */
+	return set_mission_items();
+}
 
-	_reset_loiter_pos = true;
-	_do_takeoff = false;
+bool
+Navigator::set_mission_items()
+{
+	if (_pos_sp_triplet.current.valid) {
+		memcpy(&_pos_sp_triplet.previous, &_pos_sp_triplet.current, sizeof(position_setpoint_s));
+		_pos_sp_triplet.previous.valid = true;
+	}
 
-	int ret;
 	bool onboard;
-	unsigned index;
+	int index;
 
-	ret = _mission.get_current_mission_item(&_mission_item, &onboard, &index);
+	/* if we fail to set the current mission, continue to loiter */
+	if (!_mission.get_current_mission_item(&_mission_item, &onboard, &index)) {
 
-	if (ret == OK) {
-		_mission.report_current_offboard_mission_item();
+		dispatch(EVENT_LOITER_REQUESTED);
+		return false;
+	}
 
-		_mission_item_valid = true;
-		position_setpoint_from_mission_item(&_pos_sp_triplet.current, &_mission_item);
-
-		if (_mission_item.nav_cmd != NAV_CMD_RETURN_TO_LAUNCH &&
-		    _mission_item.nav_cmd != NAV_CMD_LOITER_TIME_LIMIT &&
-		    _mission_item.nav_cmd != NAV_CMD_LOITER_TURN_COUNT &&
-		    _mission_item.nav_cmd != NAV_CMD_LOITER_UNLIMITED) {
-			/* don't reset RTL state on RTL or LOITER items */
-			_rtl_state = RTL_STATE_NONE;
-		}
+	/* if we got an RTL mission item, switch to RTL mode and give up */
+	if (_mission_item.nav_cmd == NAV_CMD_RETURN_TO_LAUNCH) {
+		dispatch(EVENT_RTL_REQUESTED);
+		return false;
+	}
 
-		if (_vstatus.is_rotary_wing) {
-			if (_need_takeoff && (
-				    _mission_item.nav_cmd == NAV_CMD_TAKEOFF ||
-				    _mission_item.nav_cmd == NAV_CMD_WAYPOINT ||
-				    _mission_item.nav_cmd == NAV_CMD_RETURN_TO_LAUNCH ||
-				    _mission_item.nav_cmd == NAV_CMD_LOITER_TIME_LIMIT ||
-				    _mission_item.nav_cmd == NAV_CMD_LOITER_TURN_COUNT ||
-				    _mission_item.nav_cmd == NAV_CMD_LOITER_UNLIMITED
-			    )) {
-				/* do special TAKEOFF handling for VTOL */
-				_need_takeoff = false;
-
-				/* calculate desired takeoff altitude AMSL */
-				float takeoff_alt_amsl = _pos_sp_triplet.current.alt;
-
-				if (_vstatus.condition_landed) {
-					/* takeoff to at least NAV_TAKEOFF_ALT from ground if landed */
-					takeoff_alt_amsl = fmaxf(takeoff_alt_amsl, _global_pos.alt + _parameters.takeoff_alt);
-				}
+	_mission_item_valid = true;
 
-				/* check if we really need takeoff */
-				if (_vstatus.condition_landed || _global_pos.alt < takeoff_alt_amsl - _mission_item.acceptance_radius) {
-					/* force TAKEOFF if landed or waypoint altitude is more than current */
-					_do_takeoff = true;
+	/* convert the current mission item and set it valid */
+	mission_item_to_position_setpoint(&_mission_item, &_pos_sp_triplet.current);
+	_pos_sp_triplet.current.valid = true;
+	
 
-					/* move current position setpoint to next */
-					memcpy(&_pos_sp_triplet.next, &_pos_sp_triplet.current, sizeof(position_setpoint_s));
+	mission_item_s next_mission_item;
 
-					/* set current setpoint to takeoff */
+	bool last_wp = false;
+	/* now try to set the next mission item as well, if there is no more next
+	 * this means we're heading to the last waypoint */
+	if (_mission.get_next_mission_item(&next_mission_item)) {
+		/* convert the next mission item and set it valid */
+		mission_item_to_position_setpoint(&next_mission_item, &_pos_sp_triplet.next);
+		_pos_sp_triplet.next.valid = true;
+	} else {
+		last_wp = true;
+	}
 
-					_pos_sp_triplet.current.lat = _global_pos.lat;
-					_pos_sp_triplet.current.lon = _global_pos.lon;
-					_pos_sp_triplet.current.alt = takeoff_alt_amsl;
-					_pos_sp_triplet.current.yaw = NAN;
-					_pos_sp_triplet.current.type = SETPOINT_TYPE_TAKEOFF;
-				}
+	/* notify user about what happened */
+	mavlink_log_info(_mavlink_fd, "#audio: heading to %s%swaypoint %d",
+		(last_wp ? "last " : "" ), (onboard ? "onboard " : ""), index);
 
-			} else if (_mission_item.nav_cmd == NAV_CMD_LAND) {
-				/* will need takeoff after landing */
-				_need_takeoff = true;
-			}
-		}
+	_update_triplet = true;
 
-		if (_do_takeoff) {
-			mavlink_log_info(_mavlink_fd, "#audio: takeoff to %.1fm above home", (double)(_pos_sp_triplet.current.alt - _home_pos.alt));
+	reset_reached();
 
-		} else {
-			if (onboard) {
-				mavlink_log_info(_mavlink_fd, "#audio: heading to onboard WP %d", index);
+	return true;
+}
 
-			} else {
-				mavlink_log_info(_mavlink_fd, "#audio: heading to offboard WP %d", index);
-			}
-		}
+bool
+Navigator::start_rtl()
+{
+	/* TODO check if RTL was successfull, if not we have a problem and need to dispatch something */
+	if (_rtl.get_current_rtl_item(&_global_pos, &_mission_item)) {
 
-	} else {
-		/* since a mission is not advanced without WPs available, this is not supposed to happen */
-		_mission_item_valid = false;
-		_pos_sp_triplet.current.valid = false;
-		warnx("ERROR: current WP can't be set");
-	}
+		_mission_item_valid = true;
 
-	if (!_do_takeoff) {
-		mission_item_s item_next;
-		ret = _mission.get_next_mission_item(&item_next);
+		mission_item_to_position_setpoint(&_mission_item, &_pos_sp_triplet.current);
+		_pos_sp_triplet.current.valid = true;
 
-		if (ret == OK) {
-			position_setpoint_from_mission_item(&_pos_sp_triplet.next, &item_next);
+		reset_reached();
 
-		} else {
-			/* this will fail for the last WP */
-			_pos_sp_triplet.next.valid = false;
-		}
+		_update_triplet = true;
+		return true;
 	}
+	dispatch(EVENT_LOITER_REQUESTED);
 
-	_pos_sp_triplet_updated = true;
+	return false;
 }
 
-void
-Navigator::start_rtl()
+bool
+Navigator::advance_rtl()
 {
-	_do_takeoff = false;
+	/* tell mission to move by one */
+	_rtl.move_to_next();
 
-	/* decide if we need climb */
-	if (_rtl_state == RTL_STATE_NONE) {
-		if (_global_pos.alt < _home_pos.alt + _parameters.rtl_alt) {
-			_rtl_state = RTL_STATE_CLIMB;
+	/* now try to set the new mission items, if it fails, it will dispatch loiter */
+	if (_rtl.get_current_rtl_item(&_global_pos, &_mission_item)) {
 
-		} else {
-			_rtl_state = RTL_STATE_RETURN;
-		}
-	}
+		_mission_item_valid = true;
 
-	/* if switching directly to return state, reset altitude setpoint */
-	if (_rtl_state == RTL_STATE_RETURN) {
-		_mission_item.altitude_is_relative = false;
-		_mission_item.altitude = _global_pos.alt;
+		mission_item_to_position_setpoint(&_mission_item, &_pos_sp_triplet.current);
+		_pos_sp_triplet.current.valid = true;
+
+		reset_reached();
+
+		_update_triplet = true;
+		return true;
 	}
 
-	_reset_loiter_pos = true;
-	set_rtl_item();
+	dispatch(EVENT_LOITER_REQUESTED);
+	return false;
 }
 
-void
+bool
 Navigator::start_land()
 {
+	/* TODO: verify/test */
+
 	reset_reached();
 
 	/* this state can be requested by commander even if no global position available,
 	 * in his case controller must perform landing without position control */
-	_do_takeoff = false;
-	_reset_loiter_pos = true;
 
 	memcpy(&_pos_sp_triplet.previous, &_pos_sp_triplet.current, sizeof(position_setpoint_s));
 
-	_mission_item_valid = true;
-
 	_mission_item.lat = _global_pos.lat;
 	_mission_item.lon = _global_pos.lon;
 	_mission_item.altitude_is_relative = false;
@@ -1220,185 +1125,22 @@ Navigator::start_land()
 	_mission_item.autocontinue = true;
 	_mission_item.origin = ORIGIN_ONBOARD;
 
-	position_setpoint_from_mission_item(&_pos_sp_triplet.current, &_mission_item);
-
-	_pos_sp_triplet.next.valid = false;
-}
-
-void
-Navigator::start_land_home()
-{
-	reset_reached();
-
-	/* land to home position, should be called when hovering above home, from RTL state */
-	_do_takeoff = false;
-	_reset_loiter_pos = true;
-
-	memcpy(&_pos_sp_triplet.previous, &_pos_sp_triplet.current, sizeof(position_setpoint_s));
-
 	_mission_item_valid = true;
 
-	_mission_item.lat = _home_pos.lat;
-	_mission_item.lon = _home_pos.lon;
-	_mission_item.altitude_is_relative = false;
-	_mission_item.altitude = _home_pos.alt;
-	_mission_item.yaw = NAN;
-	_mission_item.loiter_radius = _parameters.loiter_radius;
-	_mission_item.loiter_direction = 1;
-	_mission_item.nav_cmd = NAV_CMD_LAND;
-	_mission_item.acceptance_radius = _parameters.acceptance_radius;
-	_mission_item.time_inside = 0.0f;
-	_mission_item.pitch_min = 0.0f;
-	_mission_item.autocontinue = true;
-	_mission_item.origin = ORIGIN_ONBOARD;
-
-	position_setpoint_from_mission_item(&_pos_sp_triplet.current, &_mission_item);
+	mission_item_to_position_setpoint(&_mission_item, &_pos_sp_triplet.current);
 
 	_pos_sp_triplet.next.valid = false;
-}
-
-void
-Navigator::set_rtl_item()
-{
-	reset_reached();
-
-	switch (_rtl_state) {
-	case RTL_STATE_CLIMB: {
-			memcpy(&_pos_sp_triplet.previous, &_pos_sp_triplet.current, sizeof(position_setpoint_s));
-
-			float climb_alt = _home_pos.alt + _parameters.rtl_alt;
-
-			if (_vstatus.condition_landed) {
-				climb_alt = fmaxf(climb_alt, _global_pos.alt + _parameters.rtl_alt);
-			}
-
-			_mission_item_valid = true;
-
-			_mission_item.lat = _global_pos.lat;
-			_mission_item.lon = _global_pos.lon;
-			_mission_item.altitude_is_relative = false;
-			_mission_item.altitude = climb_alt;
-			_mission_item.yaw = NAN;
-			_mission_item.loiter_radius = _parameters.loiter_radius;
-			_mission_item.loiter_direction = 1;
-			_mission_item.nav_cmd = NAV_CMD_TAKEOFF;
-			_mission_item.acceptance_radius = _parameters.acceptance_radius;
-			_mission_item.time_inside = 0.0f;
-			_mission_item.pitch_min = 0.0f;
-			_mission_item.autocontinue = true;
-			_mission_item.origin = ORIGIN_ONBOARD;
-
-			position_setpoint_from_mission_item(&_pos_sp_triplet.current, &_mission_item);
-
-			_pos_sp_triplet.next.valid = false;
-
-			mavlink_log_info(_mavlink_fd, "#audio: RTL: climb to %.1fm above home", (double)(climb_alt - _home_pos.alt));
-			break;
-		}
-
-	case RTL_STATE_RETURN: {
-			memcpy(&_pos_sp_triplet.previous, &_pos_sp_triplet.current, sizeof(position_setpoint_s));
-
-			_mission_item_valid = true;
-
-			_mission_item.lat = _home_pos.lat;
-			_mission_item.lon = _home_pos.lon;
-			// don't change altitude
-			if (_pos_sp_triplet.previous.valid) {
-				/* if previous setpoint is valid then use it to calculate heading to home */
-				_mission_item.yaw = get_bearing_to_next_waypoint(_pos_sp_triplet.previous.lat, _pos_sp_triplet.previous.lon, _mission_item.lat, _mission_item.lon);
-
-			} else {
-				/* else use current position */
-				_mission_item.yaw = get_bearing_to_next_waypoint(_global_pos.lat, _global_pos.lon, _mission_item.lat, _mission_item.lon);
-			}
-			_mission_item.loiter_radius = _parameters.loiter_radius;
-			_mission_item.loiter_direction = 1;
-			_mission_item.nav_cmd = NAV_CMD_WAYPOINT;
-			_mission_item.acceptance_radius = _parameters.acceptance_radius;
-			_mission_item.time_inside = 0.0f;
-			_mission_item.pitch_min = 0.0f;
-			_mission_item.autocontinue = true;
-			_mission_item.origin = ORIGIN_ONBOARD;
-
-			position_setpoint_from_mission_item(&_pos_sp_triplet.current, &_mission_item);
-
-			_pos_sp_triplet.next.valid = false;
-
-			mavlink_log_info(_mavlink_fd, "#audio: RTL: return at %.1fm above home", (double)(_mission_item.altitude - _home_pos.alt));
-			break;
-		}
-
-	case RTL_STATE_DESCEND: {
-			memcpy(&_pos_sp_triplet.previous, &_pos_sp_triplet.current, sizeof(position_setpoint_s));
-
-			_mission_item_valid = true;
-
-			_mission_item.lat = _home_pos.lat;
-			_mission_item.lon = _home_pos.lon;
-			_mission_item.altitude_is_relative = false;
-			_mission_item.altitude = _home_pos.alt + _parameters.land_alt;
-			_mission_item.yaw = NAN;
-			_mission_item.loiter_radius = _parameters.loiter_radius;
-			_mission_item.loiter_direction = 1;
-			_mission_item.nav_cmd = NAV_CMD_WAYPOINT;
-			_mission_item.acceptance_radius = _parameters.acceptance_radius;
-			_mission_item.time_inside = _parameters.rtl_land_delay < 0.0f ? 0.0f : _parameters.rtl_land_delay;
-			_mission_item.pitch_min = 0.0f;
-			_mission_item.autocontinue = _parameters.rtl_land_delay > -0.001f;
-			_mission_item.origin = ORIGIN_ONBOARD;
-
-			position_setpoint_from_mission_item(&_pos_sp_triplet.current, &_mission_item);
-
-			_pos_sp_triplet.next.valid = false;
-
-			mavlink_log_info(_mavlink_fd, "#audio: RTL: descend to %.1fm above home", (double)(_mission_item.altitude - _home_pos.alt));
-			break;
-		}
-
-	default: {
-			mavlink_log_critical(_mavlink_fd, "#audio: [navigator] error: unknown RTL state: %d", _rtl_state);
-			start_loiter();
-			break;
-		}
-	}
-
-	_pos_sp_triplet_updated = true;
-}
-
-void
-Navigator::request_loiter_or_ready()
-{
-	/* XXX workaround: no landing detector for fixedwing yet */
-	if (_vstatus.condition_landed && _vstatus.is_rotary_wing) {
-		dispatch(EVENT_READY_REQUESTED);
-
-	} else {
-		dispatch(EVENT_LOITER_REQUESTED);
-	}
-}
-
-void
-Navigator::request_mission_if_available()
-{
-	if (_mission.current_mission_available()) {
-		dispatch(EVENT_MISSION_REQUESTED);
 
-	} else {
-		request_loiter_or_ready();
-	}
+	_update_triplet = true;
+	return true;
 }
 
 void
-Navigator::position_setpoint_from_mission_item(position_setpoint_s *sp, mission_item_s *item)
+Navigator::mission_item_to_position_setpoint(const mission_item_s *item, position_setpoint_s *sp)
 {
 	sp->valid = true;
 
 	if (item->nav_cmd == NAV_CMD_RETURN_TO_LAUNCH) {
-		/* set home position for RTL item */
-		sp->lat = _home_pos.lat;
-		sp->lon = _home_pos.lon;
-		sp->alt = _home_pos.alt + _parameters.rtl_alt;
 
 		if (_pos_sp_triplet.previous.valid) {
 			/* if previous setpoint is valid then use it to calculate heading to home */
@@ -1408,9 +1150,6 @@ Navigator::position_setpoint_from_mission_item(position_setpoint_s *sp, mission_
 			/* else use current position */
 			sp->yaw = get_bearing_to_next_waypoint(_global_pos.lat, _global_pos.lon, sp->lat, sp->lon);
 		}
-		sp->loiter_radius = _parameters.loiter_radius;
-		sp->loiter_direction = 1;
-		sp->pitch_min = 0.0f;
 
 	} else {
 		sp->lat = item->lat;
@@ -1450,14 +1189,14 @@ Navigator::check_mission_item_reached()
 		return _vstatus.condition_landed;
 	}
 
-	/* XXX TODO count turns */
-	if ((_mission_item.nav_cmd == NAV_CMD_LOITER_TURN_COUNT ||
-	     _mission_item.nav_cmd == NAV_CMD_LOITER_TIME_LIMIT ||
-	     _mission_item.nav_cmd == NAV_CMD_LOITER_UNLIMITED) &&
-	    _mission_item.loiter_radius > 0.01f) {
+	/* TODO count turns */
+	// if ((_mission_item.nav_cmd == NAV_CMD_LOITER_TURN_COUNT ||
+	//      _mission_item.nav_cmd == NAV_CMD_LOITER_TIME_LIMIT ||
+	//      _mission_item.nav_cmd == NAV_CMD_LOITER_UNLIMITED) &&
+	//     _mission_item.loiter_radius > 0.01f) {
 
-		return false;
-	}
+	// 	return false;
+	// }
 
 	uint64_t now = hrt_absolute_time();
 
@@ -1475,22 +1214,19 @@ Navigator::check_mission_item_reached()
 		float dist_xy = -1.0f;
 		float dist_z = -1.0f;
 
-		/* calculate AMSL altitude for this waypoint */
-		float wp_alt_amsl = _mission_item.altitude;
+		float altitude_amsl = _mission_item.altitude_is_relative
+					? _mission_item.altitude + _home_pos.alt : _mission_item.altitude;
 
-		if (_mission_item.altitude_is_relative)
-			wp_alt_amsl += _home_pos.alt;
-
-		dist = get_distance_to_point_global_wgs84(_mission_item.lat, _mission_item.lon, wp_alt_amsl,
-				(double)_global_pos.lat, (double)_global_pos.lon, _global_pos.alt,
+		dist = get_distance_to_point_global_wgs84(_mission_item.lat, _mission_item.lon, altitude_amsl,
+				_global_pos.lat, _global_pos.lon, _global_pos.alt,
 				&dist_xy, &dist_z);
 
-		if (_do_takeoff) {
-			if (_global_pos.alt > wp_alt_amsl - acceptance_radius) {
-				/* require only altitude for takeoff */
+		if (_mission_item.nav_cmd == NAV_CMD_TAKEOFF) {
+
+			/* require only altitude for takeoff */
+			if (_global_pos.alt > altitude_amsl - acceptance_radius) {
 				_waypoint_position_reached = true;
 			}
-
 		} else {
 			if (dist >= 0.0f && dist <= acceptance_radius) {
 				_waypoint_position_reached = true;
@@ -1499,7 +1235,10 @@ Navigator::check_mission_item_reached()
 	}
 
 	if (_waypoint_position_reached && !_waypoint_yaw_reached) {
-		if (_vstatus.is_rotary_wing && !_do_takeoff && isfinite(_mission_item.yaw)) {
+		
+		/* TODO: removed takeoff, why? */
+		if (_vstatus.is_rotary_wing && isfinite(_mission_item.yaw)) {
+
 			/* check yaw if defined only for rotary wing except takeoff */
 			float yaw_err = _wrap_pi(_mission_item.yaw - _global_pos.yaw);
 
@@ -1514,24 +1253,23 @@ Navigator::check_mission_item_reached()
 
 	/* check if the current waypoint was reached */
 	if (_waypoint_position_reached && _waypoint_yaw_reached) {
+
 		if (_time_first_inside_orbit == 0) {
 			_time_first_inside_orbit = now;
 
 			if (_mission_item.time_inside > 0.01f) {
-				mavlink_log_info(_mavlink_fd, "#audio: waypoint reached, wait for %.1fs", (double)_mission_item.time_inside);
+				mavlink_log_info(_mavlink_fd, "#audio: waypoint reached, wait for %.1fs",
+					(double)_mission_item.time_inside);
 			}
 		}
 
 		/* check if the MAV was long enough inside the waypoint orbit */
 		if ((now - _time_first_inside_orbit >= (uint64_t)_mission_item.time_inside * 1e6)
 		    || _mission_item.nav_cmd == NAV_CMD_TAKEOFF) {
-			reset_reached();
 			return true;
 		}
 	}
-
 	return false;
-
 }
 
 void
@@ -1544,62 +1282,6 @@ Navigator::reset_reached()
 }
 
 void
-Navigator::on_mission_item_reached()
-{
-	if (myState == NAV_STATE_MISSION) {
-
-		_mission.report_mission_item_reached();
-
-		if (_do_takeoff) {
-			/* takeoff completed */
-			_do_takeoff = false;
-			mavlink_log_info(_mavlink_fd, "#audio: takeoff completed");
-
-		} else {
-			/* advance by one mission item */
-			_mission.move_to_next();
-		}
-
-		if (_mission.current_mission_available()) {
-			set_mission_item();
-
-		} else {
-			/* if no more mission items available then finish mission */
-			/* loiter at last waypoint */
-			_reset_loiter_pos = false;
-			mavlink_log_info(_mavlink_fd, "[navigator] mission completed");
-			request_loiter_or_ready();
-		}
-
-	} else if (myState == NAV_STATE_RTL) {
-		/* RTL completed */
-		if (_rtl_state == RTL_STATE_DESCEND) {
-			/* hovering above home position, land if needed or loiter */
-			mavlink_log_info(_mavlink_fd, "[navigator] RTL completed");
-
-			if (_mission_item.autocontinue) {
-				dispatch(EVENT_LAND_REQUESTED);
-
-			} else {
-				_reset_loiter_pos = false;
-				dispatch(EVENT_LOITER_REQUESTED);
-			}
-
-		} else {
-			/* next RTL step */
-			_rtl_state = (RTLState)(_rtl_state + 1);
-			set_rtl_item();
-		}
-
-	} else if (myState == NAV_STATE_LAND) {
-		/* landing completed */
-		mavlink_log_info(_mavlink_fd, "[navigator] landing completed");
-		dispatch(EVENT_READY_REQUESTED);
-	}
-	_mission.publish_mission_result();
-}
-
-void
 Navigator::publish_position_setpoint_triplet()
 {
 	/* update navigation state */
@@ -1607,11 +1289,9 @@ Navigator::publish_position_setpoint_triplet()
 
 	/* lazily publish the position setpoint triplet only once available */
 	if (_pos_sp_triplet_pub > 0) {
-		/* publish the position setpoint triplet */
 		orb_publish(ORB_ID(position_setpoint_triplet), _pos_sp_triplet_pub, &_pos_sp_triplet);
 
 	} else {
-		/* advertise and publish */
 		_pos_sp_triplet_pub = orb_advertise(ORB_ID(position_setpoint_triplet), &_pos_sp_triplet);
 	}
 }