Airspeed selector: remove ASPD_STALL and replace by FW_AIRSPD_STALL

Signed-off-by: Silvan Fuhrer <silvan@auterion.com>

ROMFS/px4fmu_common/init.d-posix/airframes/17001_tf-g1

@@ -14,7 +14,8 @@
 
 param set-default EKF2_ARSP_THR 8
 param set-default EKF2_FUSE_BETA 1
-param set-default ASPD_STALL 10.0
+
+param set-default FW_AIRSPD_STALL 8
 
 param set-default FW_P_RMAX_NEG 20.0
 param set-default FW_P_RMAX_POS 60.0

src/modules/airspeed_selector/airspeed_selector_main.cpp

@@ -170,8 +170,7 @@ private:
 		(ParamFloat<px4::params::ASPD_FS_INNOV>) _tas_innov_threshold, /**< innovation check threshold */
 		(ParamFloat<px4::params::ASPD_FS_INTEG>) _tas_innov_integ_threshold, /**< innovation check integrator threshold */
 		(ParamInt<px4::params::ASPD_FS_T_STOP>) _checks_fail_delay, /**< delay to declare airspeed invalid */
-		(ParamInt<px4::params::ASPD_FS_T_START>) _checks_clear_delay, /**<  delay to declare airspeed valid again */
+		(ParamInt<px4::params::ASPD_FS_T_START>) _checks_clear_delay /**<  delay to declare airspeed valid again */
-		(ParamFloat<px4::params::ASPD_STALL>) _airspeed_stall /**<  stall speed*/
 	)
 
 	void 		init(); 	/**< initialization of the airspeed validator instances */
@@ -295,8 +294,6 @@ AirspeedModule::Run()
 		update_params();
 	}
 
-
-
 	bool armed = (_vehicle_status.arming_state == vehicle_status_s::ARMING_STATE_ARMED);
 
 	// check for new connected airspeed sensors as long as we're disarmed
@@ -348,8 +345,11 @@ AirspeedModule::Run()
 				input_data.airspeed_timestamp = airspeed_raw.timestamp;
 				input_data.air_temperature_celsius = airspeed_raw.air_temperature_celsius;
 
+				float airspeed_stall = 7.0f;
+				param_get(param_find("FW_AIRSPD_STALL"), &airspeed_stall);
+
 				// takeoff situation is active from start till one of the sensors' IAS or groundspeed_CAS is above stall speed
-				if (airspeed_raw.indicated_airspeed_m_s > _airspeed_stall.get() || _ground_minus_wind_CAS > _airspeed_stall.get()) {
+				if (airspeed_raw.indicated_airspeed_m_s > airspeed_stall || _ground_minus_wind_CAS > airspeed_stall) {
 					_in_takeoff_situation = false;
 				}
 
@@ -386,6 +386,9 @@ void AirspeedModule::update_params()
 {
 	updateParams();
 
+	float airspeed_stall = 7.0f;
+	param_get(param_find("FW_AIRSPD_STALL"), &airspeed_stall);
+
 	_wind_estimator_sideslip.set_wind_p_noise(_param_west_w_p_noise.get());
 	_wind_estimator_sideslip.set_tas_scale_p_noise(_param_west_sc_p_noise.get());
 	_wind_estimator_sideslip.set_tas_noise(_param_west_tas_noise.get());
@@ -410,7 +413,7 @@ void AirspeedModule::update_params()
 		_airspeed_validator[i].set_tas_innov_integ_threshold(_tas_innov_integ_threshold.get());
 		_airspeed_validator[i].set_checks_fail_delay(_checks_fail_delay.get());
 		_airspeed_validator[i].set_checks_clear_delay(_checks_clear_delay.get());
-		_airspeed_validator[i].set_airspeed_stall(_airspeed_stall.get());
+		_airspeed_validator[i].set_airspeed_stall(airspeed_stall);
 	}
 
 	// if the airspeed scale estimation is enabled and the airspeed is valid,

src/modules/airspeed_selector/airspeed_selector_params.c

@@ -184,15 +184,3 @@ PARAM_DEFINE_INT32(ASPD_FS_T_STOP, 2);
  * @max 1000
  */
 PARAM_DEFINE_INT32(ASPD_FS_T_START, -1);
-
-/**
- * Airspeed fault detection stall airspeed
- *
- * This is the minimum indicated airspeed at which the wing can produce 1g of lift.
- * It is used by the airspeed sensor fault detection and failsafe calculation to detect a
- * significant airspeed low measurement error condition and should be set based on flight test for reliable operation.
- *
- * @group Airspeed Validator
- * @unit m/s
- */
-PARAM_DEFINE_FLOAT(ASPD_STALL, 10.0f);

src/modules/commander/Arming/PreFlightCheck/PreFlightCheck.cpp

@@ -184,10 +184,10 @@ bool PreFlightCheck::preflightCheck(orb_advert_t *mavlink_log_pub, vehicle_statu
 		int32_t max_airspeed_check_en = 0;
 		param_get(param_find("COM_ARM_ARSP_EN"), &max_airspeed_check_en);
 
-		float airspeed_stall = 10.0f;
+		float airspeed_trim = 10.0f;
-		param_get(param_find("ASPD_STALL"), &airspeed_stall);
+		param_get(param_find("FW_AIRSPD_TRIM"), &airspeed_trim);
 
-		const float arming_max_airspeed_allowed = airspeed_stall / 2.0f; // set to half of stall speed
+		const float arming_max_airspeed_allowed = airspeed_trim / 2.0f; // set to half of trim airspeed
 
 		if (!airspeedCheck(mavlink_log_pub, status, optional, report_failures, prearm, (bool)max_airspeed_check_en,
 				   arming_max_airspeed_allowed)

src/modules/commander/commander_params.c

@@ -989,7 +989,7 @@ PARAM_DEFINE_FLOAT(COM_LKDOWN_TKO, 3.0f);
 /**
 * Enable preflight check for maximal allowed airspeed when arming.
 *
-* Deny arming if the current airspeed measurement is greater than half the stall speed (ASPD_STALL).
+* Deny arming if the current airspeed measurement is greater than half the cruise airspeed (FW_AIRSPD_TRIM).
 * Excessive airspeed measurements on ground are either caused by wind or bad airspeed calibration.
 *
 * @group Commander

src/modules/fw_att_control/FixedwingAttitudeControl.cpp

@@ -245,7 +245,7 @@ float FixedwingAttitudeControl::get_airspeed_and_update_scaling()
 		// than the minimum airspeed
 		if (_vehicle_status.is_vtol && _vehicle_status.vehicle_type == vehicle_status_s::VEHICLE_TYPE_ROTARY_WING
 		    && !_vehicle_status.in_transition_mode) {
-			airspeed = _param_fw_airspd_min.get();
+			airspeed = _param_fw_airspd_stall.get();
 		}
 	}
 
@@ -256,7 +256,7 @@ float FixedwingAttitudeControl::get_airspeed_and_update_scaling()
 	 *
 	 * Forcing the scaling to this value allows reasonable handheld tests.
 	 */
-	const float airspeed_constrained = constrain(constrain(airspeed, _param_fw_airspd_min.get(),
+	const float airspeed_constrained = constrain(constrain(airspeed, _param_fw_airspd_stall.get(),
 					   _param_fw_airspd_max.get()), 0.1f, 1000.0f);
 
 	_airspeed_scaling = (_param_fw_arsp_scale_en.get()) ? (_param_fw_airspd_trim.get() / airspeed_constrained) : 1.0f;
@@ -427,7 +427,7 @@ void FixedwingAttitudeControl::Run()
 			control_input.roll_setpoint = _att_sp.roll_body;
 			control_input.pitch_setpoint = _att_sp.pitch_body;
 			control_input.yaw_setpoint = _att_sp.yaw_body;
-			control_input.airspeed_min = _param_fw_airspd_min.get();
+			control_input.airspeed_min = _param_fw_airspd_stall.get();
 			control_input.airspeed_max = _param_fw_airspd_max.get();
 			control_input.airspeed = airspeed;
 			control_input.scaler = _airspeed_scaling;
@@ -436,11 +436,11 @@ void FixedwingAttitudeControl::Run()
 			if (wheel_control) {
 				_local_pos_sub.update(&_local_pos);
 
-				/* Use min airspeed to calculate ground speed scaling region.
+				/* Use stall airspeed to calculate ground speed scaling region.
 				* Don't scale below gspd_scaling_trim
 				*/
 				float groundspeed = sqrtf(_local_pos.vx * _local_pos.vx + _local_pos.vy * _local_pos.vy);
-				float gspd_scaling_trim = (_param_fw_airspd_min.get() * 0.6f);
+				float gspd_scaling_trim = (_param_fw_airspd_stall.get());
 
 				control_input.groundspeed = groundspeed;
 
@@ -477,11 +477,11 @@ void FixedwingAttitudeControl::Run()
 			float trim_yaw = _param_trim_yaw.get();
 
 			if (airspeed < _param_fw_airspd_trim.get()) {
-				trim_roll += gradual(airspeed, _param_fw_airspd_min.get(), _param_fw_airspd_trim.get(), _param_fw_dtrim_r_vmin.get(),
+				trim_roll += gradual(airspeed, _param_fw_airspd_stall.get(), _param_fw_airspd_trim.get(), _param_fw_dtrim_r_vmin.get(),
 						     0.0f);
-				trim_pitch += gradual(airspeed, _param_fw_airspd_min.get(), _param_fw_airspd_trim.get(), _param_fw_dtrim_p_vmin.get(),
+				trim_pitch += gradual(airspeed, _param_fw_airspd_stall.get(), _param_fw_airspd_trim.get(), _param_fw_dtrim_p_vmin.get(),
 						      0.0f);
-				trim_yaw += gradual(airspeed, _param_fw_airspd_min.get(), _param_fw_airspd_trim.get(), _param_fw_dtrim_y_vmin.get(),
+				trim_yaw += gradual(airspeed, _param_fw_airspd_stall.get(), _param_fw_airspd_trim.get(), _param_fw_dtrim_y_vmin.get(),
 						    0.0f);
 
 			} else {

src/modules/fw_att_control/FixedwingAttitudeControl.hpp

@@ -147,7 +147,7 @@ private:
 		(ParamFloat<px4::params::FW_ACRO_Z_MAX>) _param_fw_acro_z_max,
 
 		(ParamFloat<px4::params::FW_AIRSPD_MAX>) _param_fw_airspd_max,
-		(ParamFloat<px4::params::FW_AIRSPD_MIN>) _param_fw_airspd_min,
+		(ParamFloat<px4::params::FW_AIRSPD_STALL>) _param_fw_airspd_stall,
 		(ParamFloat<px4::params::FW_AIRSPD_TRIM>) _param_fw_airspd_trim,
 		(ParamInt<px4::params::FW_ARSP_MODE>) _param_fw_arsp_mode,
 

src/modules/fw_pos_control_l1/fw_pos_control_l1_params.c

@@ -433,7 +433,8 @@ PARAM_DEFINE_FLOAT(FW_LND_THRTC_SC, 1.0f);
 /**
  * Minimum Airspeed (CAS)
  *
- * If the CAS (calibrated airspeed) falls below this value, the TECS controller will try to
+ * The minimal airspeed (calibrated airspeed) the user is able to command.
+ * Further, if the airspeed falls below this value, the TECS controller will try to
  * increase airspeed more aggressively.
  *
  * @unit m/s
@@ -476,6 +477,22 @@ PARAM_DEFINE_FLOAT(FW_AIRSPD_MAX, 20.0f);
  */
 PARAM_DEFINE_FLOAT(FW_AIRSPD_TRIM, 15.0f);
 
+/**
+ * Stall Airspeed (CAS)
+ *
+ * The stall airspeed (calibrated airspeed) of the vehicle.
+ * It is used for airspeed sensor failure detection and for the control
+ * surface scaling airspeed limits.
+ *
+ * @unit m/s
+ * @min 0.5
+ * @max 40
+ * @decimal 1
+ * @increment 0.5
+ * @group FW TECS
+ */
+PARAM_DEFINE_FLOAT(FW_AIRSPD_STALL, 7.0f);
+
 /**
  * Maximum climb rate
  *