multicopter manual attitude control: Leave some margin for yaw control

src/modules/mc_att_control/mc_att_control_main.cpp

@@ -97,6 +97,7 @@ extern "C" __EXPORT int mc_att_control_main(int argc, char *argv[]);
 #define YAW_DEADZONE	0.05f
 #define MIN_TAKEOFF_THRUST    0.2f
 #define RATES_I_LIMIT	0.3f
+#define MANUAL_THROTTLE_MAX_MULTICOPTER	0.9f
 
 class MulticopterAttitudeControl
 {
@@ -831,7 +832,7 @@ MulticopterAttitudeControl::task_main()
 				if (_v_control_mode.flag_control_manual_enabled) {
 					/* manual rates control - ACRO mode */
 					_rates_sp = math::Vector<3>(_manual_control_sp.y, -_manual_control_sp.x, _manual_control_sp.r).emult(_params.acro_rate_max);
-					_thrust_sp = _manual_control_sp.z;
+					_thrust_sp = math::min(_manual_control_sp.z, MANUAL_THROTTLE_MAX_MULTICOPTER);
 
 					/* publish attitude rates setpoint */
 					_v_rates_sp.roll = _rates_sp(0);

src/modules/mc_pos_control/mc_pos_control_main.cpp

@@ -83,6 +83,7 @@
 #define TILT_COS_MAX	0.7f
 #define SIGMA			0.000001f
 #define MIN_DIST		0.01f
+#define MANUAL_THROTTLE_MAX_MULTICOPTER	0.9f
 
 /**
  * Multicopter position control app start / stop handling function
@@ -1387,7 +1388,7 @@ MulticopterPositionControl::task_main()
 
 			//Control climb rate directly if no aiding altitude controller is active
 			if(!_control_mode.flag_control_climb_rate_enabled) {
-				_att_sp.thrust = _manual.z;
+				_att_sp.thrust = math::min(_manual.z, MANUAL_THROTTLE_MAX_MULTICOPTER);
 			}
 
 			//Construct attitude setpoint rotation matrix