Support more failsafe actions on data link and RC loss

src/modules/navigator/navigator.h

@@ -266,8 +266,8 @@ private:
 
 	control::BlockParamFloat _param_loiter_radius;	/**< loiter radius for fixedwing */
 	control::BlockParamFloat _param_acceptance_radius;	/**< acceptance for takeoff */
-	control::BlockParamInt _param_datalinkloss_obc;	/**< if true: obc mode on data link loss enabled */
-	control::BlockParamInt _param_rcloss_obc;	/**< if true: obc mode on rc loss enabled */
+	control::BlockParamInt _param_datalinkloss_act;	/**< select data link loss action */
+	control::BlockParamInt _param_rcloss_act;	/**< select data link loss action */
 	
 	control::BlockParamFloat _param_cruising_speed_hover;
 	control::BlockParamFloat _param_cruising_speed_plane;

src/modules/navigator/navigator_main.cpp

@@ -153,8 +153,8 @@ Navigator::Navigator() :
 	_follow_target(this, "TAR"),
 	_param_loiter_radius(this, "LOITER_RAD"),
 	_param_acceptance_radius(this, "ACC_RAD"),
-	_param_datalinkloss_obc(this, "DLL_OBC"),
-	_param_rcloss_obc(this, "RCL_OBC"),
+	_param_datalinkloss_act(this, "DLL_ACT"),
+	_param_rcloss_act(this, "RCL_ACT"),
 	_param_cruising_speed_hover(this, "MPC_XY_CRUISE", false),
 	_param_cruising_speed_plane(this, "FW_AIRSPD_TRIM", false),
 	_mission_cruising_speed(-1.0f)
@@ -481,9 +481,13 @@ Navigator::task_main()
 				break;
 			case vehicle_status_s::NAVIGATION_STATE_AUTO_RCRECOVER:
 				_pos_sp_triplet_published_invalid_once = false;
-				if (_param_rcloss_obc.get() != 0) {
+				if (_param_rcloss_act.get() == 0) {
+					_navigation_mode = &_loiter;
+				} else if (_param_rcloss_act.get() == 2) {
+					_navigation_mode = &_land;
+				} else if (_param_rcloss_act.get() == 3) {
 					_navigation_mode = &_rcLoss;
-				} else {
+				} else { /* if == 1 or unknown, RTL */
 					_navigation_mode = &_rtl;
 				}
 				break;
@@ -507,9 +511,13 @@ Navigator::task_main()
 				/* Use complex data link loss mode only when enabled via param
 				* otherwise use rtl */
 				_pos_sp_triplet_published_invalid_once = false;
-				if (_param_datalinkloss_obc.get() != 0) {
+				if (_param_datalinkloss_act.get() == 0) {
+					_navigation_mode = &_loiter;
+				} else if (_param_datalinkloss_act.get() == 2) {
+					_navigation_mode = &_land;
+				} else if (_param_datalinkloss_act.get() == 3) {
 					_navigation_mode = &_dataLinkLoss;
-				} else {
+				} else { /* if == 1 or unknown, RTL */
 					_navigation_mode = &_rtl;
 				}
 				break;

src/modules/navigator/navigator_params.c

@@ -65,24 +65,37 @@ PARAM_DEFINE_FLOAT(NAV_LOITER_RAD, 50.0f);
 PARAM_DEFINE_FLOAT(NAV_ACC_RAD, 10.0f);
 
 /**
- * Set OBC mode for data link loss
+ * Set data link loss failsafe mode
  *
- * If set to 1 the behaviour on data link loss is set to a mode according to the Outback Challenge (OBC) rules
+ * The data link loss failsafe will only be entered after a timeout,
+ * set by a DIFFERENT parameter. If the timeout value is smaller than
+ * zero it will never be entered.
+ *
+ * @value 0 Loiter
+ * @value 1 Return to Land
+ * @value 2 Land at current position
+ * @value 3 Outback Challenge (OBC) rules
  *
- * @boolean
  * @group Mission
  */
-PARAM_DEFINE_INT32(NAV_DLL_OBC, 0);
+PARAM_DEFINE_INT32(NAV_DLL_ACT, 1);
 
 /**
- * Set OBC mode for rc loss
+ * Set RC loss failsafe mode
+ *
+ * The RC loss failsafe will only be entered after a timeout,
+ * set by a DIFFERENT parameter. If the timeout value is smaller than
+ * zero it will never be entered. If RC input checks have been disabled
+ * by setting the COM_RC_IN_MODE param it will also not be triggered.
  *
- * If set to 1 the behaviour on data link loss is set to a mode according to the Outback Challenge (OBC) rules
+ * @value 0 Loiter
+ * @value 1 Return to Land
+ * @value 2 Land at current position
+ * @value 3 Outback Challenge (OBC) rules
  *
- * @boolean
  * @group Mission
  */
-PARAM_DEFINE_INT32(NAV_RCL_OBC, 0);
+PARAM_DEFINE_INT32(NAV_RCL_ACT, 1);
 
 /**
  * Airfield home Lat