Ability to disable airspeed scaling (#14334)

src/modules/fw_att_control/FixedwingAttitudeControl.cpp

@@ -263,7 +263,8 @@ float FixedwingAttitudeControl::get_airspeed_and_update_scaling()
 	 * Forcing the scaling to this value allows reasonable handheld tests.
 	 */
 	const float airspeed_constrained = constrain(airspeed, _param_fw_airspd_min.get(), _param_fw_airspd_max.get());
-	_airspeed_scaling = _param_fw_airspd_trim.get() / airspeed_constrained;
+
+	_airspeed_scaling = (_param_fw_arsp_scale_en.get()) ? (_param_fw_airspd_trim.get() / airspeed_constrained) : 1.0f;
 
 	return airspeed;
 }

src/modules/fw_att_control/FixedwingAttitudeControl.hpp

@@ -149,6 +149,8 @@ private:
 		(ParamFloat<px4::params::FW_AIRSPD_TRIM>) _param_fw_airspd_trim,
 		(ParamInt<px4::params::FW_ARSP_MODE>) _param_fw_arsp_mode,
 
+		(ParamInt<px4::params::FW_ARSP_SCALE_EN>) _param_fw_arsp_scale_en,
+
 		(ParamBool<px4::params::FW_BAT_SCALE_EN>) _param_fw_bat_scale_en,
 
 		(ParamFloat<px4::params::FW_DTRIM_P_FLPS>) _param_fw_dtrim_p_flps,

src/modules/fw_att_control/fw_att_control_params.c

@@ -537,6 +537,21 @@ PARAM_DEFINE_FLOAT(FW_FLAPERON_SCL, 0.0f);
  */
 PARAM_DEFINE_INT32(FW_ARSP_MODE, 0);
 
+/**
+ * Enable airspeed scaling
+ *
+ * This enables a logic that automatically adjusts the output of the rate controller to take
+ * into account the real torque produced by an aerodynamic control surface given
+ * the current deviation from the trim airspeed (FW_AIRSPD_TRIM).
+ *
+ * Enable when using aerodynamic control surfaces (e.g.: plane)
+ * Disable when using rotor wings (e.g.: autogyro)
+ *
+ * @boolean
+ * @group FW Attitude Control
+ */
+PARAM_DEFINE_INT32(FW_ARSP_SCALE_EN, 1);
+
 /**
  * Manual roll scale
  *