RTL: enable precision landing at the end of RTL, configurable by parameter

src/modules/navigator/rtl.cpp

@@ -52,6 +52,14 @@ RTL::RTL(Navigator *navigator) :
 {
 }
 
+void
+RTL::on_inactivation()
+{
+	if (_navigator->get_precland()->is_activated()) {
+		_navigator->get_precland()->on_inactivation();
+	}
+}
+
 void
 RTL::on_inactive()
 {
@@ -223,6 +231,14 @@ RTL::on_active()
 	if (_rtl_state != RTL_STATE_LANDED && is_mission_item_reached()) {
 		advance_rtl();
 		set_rtl_item();
+
+	}
+
+	if (_rtl_state == RTL_STATE_LAND && _param_rtl_pld_md.get() > 0) {
+		_navigator->get_precland()->on_active();
+
+	} else if (_navigator->get_precland()->is_activated()) {
+		_navigator->get_precland()->on_inactivation();
 	}
 }
 
@@ -389,6 +405,16 @@ RTL::set_rtl_item()
 			_mission_item.time_inside = 0.0f;
 			_mission_item.autocontinue = true;
 			_mission_item.origin = ORIGIN_ONBOARD;
+			_mission_item.land_precision = _param_rtl_pld_md.get();
+
+			if (_mission_item.land_precision == 1) {
+				_navigator->get_precland()->set_mode(PrecLandMode::Opportunistic);
+				_navigator->get_precland()->on_activation();
+
+			} else if (_mission_item.land_precision == 2) {
+				_navigator->get_precland()->set_mode(PrecLandMode::Required);
+				_navigator->get_precland()->on_activation();
+			}
 
 			mavlink_log_info(_navigator->get_mavlink_log_pub(), "RTL: land at destination");
 			break;

src/modules/navigator/rtl.h

@@ -70,6 +70,7 @@ public:
 
 	~RTL() = default;
 
+	void on_inactivation() override;
 	void on_inactive() override;
 	void on_activation() override;
 	void on_active() override;
@@ -137,6 +138,7 @@ private:
 		(ParamFloat<px4::params::RTL_LAND_DELAY>) _param_rtl_land_delay,
 		(ParamFloat<px4::params::RTL_MIN_DIST>) _param_rtl_min_dist,
 		(ParamInt<px4::params::RTL_TYPE>) _param_rtl_type,
-		(ParamInt<px4::params::RTL_CONE_ANG>) _param_rtl_cone_half_angle_deg
+		(ParamInt<px4::params::RTL_CONE_ANG>) _param_rtl_cone_half_angle_deg,
+		(ParamInt<px4::params::RTL_PLD_MD>) _param_rtl_pld_md
 	)
 };

src/modules/navigator/rtl_params.c

@@ -135,3 +135,15 @@ PARAM_DEFINE_INT32(RTL_TYPE, 0);
  * @group Return Mode
  */
 PARAM_DEFINE_INT32(RTL_CONE_ANG, 0);
+
+/**
+ * RTL precision land mode
+ *
+ * Use precision landing when doing an RTL landing phase.
+ *
+ * @value 0 No precision landing
+ * @value 1 Opportunistic precision landing
+ * @value 2 Required precision landing
+ * @group Return To Land
+ */
+PARAM_DEFINE_INT32(RTL_PLD_MD, 0);