set actuator commands to zero if vehicle status is still unknown

src/modules/simulator/simulator_mavlink.cpp

@@ -64,7 +64,7 @@ static socklen_t _addrlen = sizeof(_srcaddr);
 using namespace simulator;
 
 void Simulator::pack_actuator_message(mavlink_hil_controls_t &actuator_msg) {
-	float out[8];
+	float out[8] = {};
 
 	const float pwm_center = (PWM_HIGHEST_MAX + PWM_LOWEST_MIN) / 2;
 
@@ -95,6 +95,12 @@ void Simulator::pack_actuator_message(mavlink_hil_controls_t &actuator_msg) {
 		}
 	}
 
+	// if vehicle status has not yet been updated, set actuator commands to zero
+	// this is to prevent the simulation getting into a bad state
+	if (_vehicle_status.timestamp == 0) {
+		memset(out, 0, sizeof(out));
+	}
+
 	actuator_msg.time_usec = hrt_absolute_time();
 	actuator_msg.roll_ailerons = out[0];
 	actuator_msg.pitch_elevator = _vehicle_status.is_rotary_wing ? out[1] : -out[1];