commander: require only valid velocity for EASY mode, allows flying with FLOW and no GPS

src/modules/commander/commander.cpp

@@ -853,6 +853,7 @@ int commander_thread_main(int argc, char *argv[])
 		/* update condition_local_position_valid and condition_local_altitude_valid */
 		check_valid(local_position.timestamp, POSITION_TIMEOUT, local_position.xy_valid, &(status.condition_local_position_valid), &status_changed);
 		check_valid(local_position.timestamp, POSITION_TIMEOUT, local_position.z_valid, &(status.condition_local_altitude_valid), &status_changed);
+		check_valid(local_position.timestamp, POSITION_TIMEOUT, local_position.v_xy_valid, &(status.condition_local_velocity_valid), &status_changed);
 
 		if (status.condition_local_altitude_valid) {
 			if (status.condition_landed != local_position.landed) {

src/modules/commander/state_machine_helper.cpp

@@ -238,9 +238,8 @@ main_state_transition(struct vehicle_status_s *current_state, main_state_t new_m
 
 		case MAIN_STATE_EASY:
 
-			/* need at minimum local position estimate */
-			if (current_state->condition_local_position_valid ||
-				current_state->condition_global_position_valid) {
+			/* need at minimum local velocity estimate */
+			if (current_state->condition_local_velocity_valid) {
 				ret = TRANSITION_CHANGED;
 			}
 

src/modules/uORB/topics/vehicle_status.h

@@ -201,6 +201,7 @@ struct vehicle_status_s
 	bool condition_home_position_valid;		/**< indicates a valid home position (a valid home position is not always a valid launch) */
 	bool condition_local_position_valid;
 	bool condition_local_altitude_valid;
+	bool condition_local_velocity_valid;
 	bool condition_airspeed_valid;			/**< set to true by the commander app if there is a valid airspeed measurement available */
 	bool condition_landed;					/**< true if vehicle is landed, always true if disarmed */