Esempio n. 1
0
void vtol_follower_control_settings_updated(UAVObjEvent * ev,
		void *ctx, void *obj, int len)
{
	(void) ctx; (void) obj; (void) len;

	VtolPathFollowerSettingsGet(&guidanceSettings);

	// Configure the velocity control PID loops
	pid_configure(&vtol_pids[NORTH_VELOCITY],
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KP], // Kp
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KI], // Ki
		0, // Kd
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_ILIMIT]);
	pid_configure(&vtol_pids[EAST_VELOCITY],
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KP], // Kp
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KI], // Ki
		0, // Kd
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_ILIMIT]);

	// Configure the position control (velocity output) PID loops
	pid_configure(&vtol_pids[NORTH_POSITION],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KP],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KI],
		0,
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_ILIMIT]);
	pid_configure(&vtol_pids[EAST_POSITION],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KP],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KI],
		0,
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_ILIMIT]);

	// The parameters for vertical control are shared with Altitude Hold
	AltitudeHoldSettingsGet(&altitudeHoldSettings);
	pid_configure(&vtol_pids[DOWN_POSITION], altitudeHoldSettings.PositionKp, 0, 0, 0);
	pid_configure(&vtol_pids[DOWN_VELOCITY],
	              altitudeHoldSettings.VelocityKp, altitudeHoldSettings.VelocityKi,
	              0, 1);  // Note the ILimit here is 1 because we use this offset to set the throttle offset

	// Calculate the constants used in the deadband calculation
	cubic_deadband_setup(guidanceSettings.EndpointDeadbandWidth,
	    guidanceSettings.EndpointDeadbandCenterGain,
	    &vtol_end_m, &vtol_end_r);

	cubic_deadband_setup(guidanceSettings.PathDeadbandWidth,
	    guidanceSettings.PathDeadbandCenterGain,
	    &vtol_path_m, &vtol_path_r);

	// calculate the loiter time constants.
	loiter_brakealpha = expf(-(guidanceSettings.UpdatePeriod / 1000.0f) / guidanceSettings.LoiterBrakingTimeConstant);
	loiter_errordecayalpha = expf(-(guidanceSettings.UpdatePeriod / 1000.0f) / guidanceSettings.LoiterErrorDecayConstant);
}
Esempio n. 2
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void vtol_follower_control_settings_updated(UAVObjEvent * ev)
{
	VtolPathFollowerSettingsGet(&guidanceSettings);

	// Configure the velocity control PID loops
	pid_configure(&vtol_pids[NORTH_VELOCITY],
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KP], // Kp
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KI], // Ki
		0, // Kd
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_ILIMIT]);
	pid_configure(&vtol_pids[EAST_VELOCITY],
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KP], // Kp
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KI], // Ki
		0, // Kd
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_ILIMIT]);

	// Configure the position control (velocity output) PID loops
	pid_configure(&vtol_pids[NORTH_POSITION],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KP],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KI],
		0,
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_ILIMIT]);
	pid_configure(&vtol_pids[EAST_POSITION],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KP],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KI],
		0,
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_ILIMIT]);

	// The parameters for vertical control are shared with Altitude Hold
	AltitudeHoldSettingsGet(&altitudeHoldSettings);
	pid_configure(&vtol_pids[DOWN_POSITION], altitudeHoldSettings.PositionKp, 0, 0, 0);
	pid_configure(&vtol_pids[DOWN_VELOCITY],
	              altitudeHoldSettings.VelocityKp, altitudeHoldSettings.VelocityKi,
	              0, 1);  // Note the ILimit here is 1 because we use this offset to set the throttle offset

	// Calculate the constants used in the deadband calculation
	vtol_deadband_setup(guidanceSettings.EndpointDeadbandWidth,
	    guidanceSettings.EndpointDeadbandCenterGain,
	    &vtol_end_m, &vtol_end_r);

	vtol_deadband_setup(guidanceSettings.PathDeadbandWidth,
	    guidanceSettings.PathDeadbandCenterGain,
	    &vtol_path_m, &vtol_path_r);

}
Esempio n. 3
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static void SettingsUpdatedCb(UAVObjEvent * ev)
{
	VtolPathFollowerSettingsGet(&guidanceSettings);

	// Configure the velocity control PID loops
	pid_configure(&vtol_pids[NORTH_VELOCITY], 
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KP], // Kp
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KI], // Ki
		0, // Kd
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_ILIMIT]);
	pid_configure(&vtol_pids[EAST_VELOCITY], 
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KP], // Kp
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KI], // Ki
		0, // Kd
		guidanceSettings.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_ILIMIT]);
	pid_configure(&vtol_pids[DOWN_VELOCITY], 
		guidanceSettings.VerticalVelPID[VTOLPATHFOLLOWERSETTINGS_VERTICALVELPID_KP], // Kp
		guidanceSettings.VerticalVelPID[VTOLPATHFOLLOWERSETTINGS_VERTICALVELPID_KI], // Ki
		0, // Kd
		guidanceSettings.VerticalVelPID[VTOLPATHFOLLOWERSETTINGS_VERTICALVELPID_ILIMIT]);

	// Configure the position control (velocity output) PID loops
	pid_configure(&vtol_pids[NORTH_POSITION],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KP],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KI],
		0,
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_ILIMIT]);
	pid_configure(&vtol_pids[EAST_POSITION],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KP],
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KI],
		0,
		guidanceSettings.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_ILIMIT]);
	pid_configure(&vtol_pids[DOWN_POSITION],
		guidanceSettings.VerticalPosPI[VTOLPATHFOLLOWERSETTINGS_VERTICALPOSPI_KP],
		guidanceSettings.VerticalPosPI[VTOLPATHFOLLOWERSETTINGS_VERTICALPOSPI_KI],
		0,
		guidanceSettings.VerticalPosPI[VTOLPATHFOLLOWERSETTINGS_VERTICALPOSPI_ILIMIT]);


	PathDesiredGet(&pathDesired);
}
Esempio n. 4
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/**
 * Compute desired attitude from the desired velocity
 *
 * Takes in @ref NedActual which has the acceleration in the 
 * NED frame as the feedback term and then compares the 
 * @ref VelocityActual against the @ref VelocityDesired
 */
static void updateVtolDesiredAttitude()
{
	float dT = guidanceSettings.UpdatePeriod / 1000.0f;

	VelocityDesiredData velocityDesired;
	VelocityActualData velocityActual;
	StabilizationDesiredData stabDesired;
	AttitudeActualData attitudeActual;
	NedAccelData nedAccel;
	StabilizationSettingsData stabSettings;

	float northError;
	float northCommand;
	
	float eastError;
	float eastCommand;

	float downError;
	float downCommand;
		
	VtolPathFollowerSettingsGet(&guidanceSettings);
	
	VelocityActualGet(&velocityActual);
	VelocityDesiredGet(&velocityDesired);
	StabilizationDesiredGet(&stabDesired);
	VelocityDesiredGet(&velocityDesired);
	AttitudeActualGet(&attitudeActual);
	StabilizationSettingsGet(&stabSettings);
	NedAccelGet(&nedAccel);
	
	float northVel = velocityActual.North;
	float eastVel = velocityActual.East;
	float downVel = velocityActual.Down;

	// Compute desired north command from velocity error
	northError = velocityDesired.North - northVel;
	northCommand = pid_apply_antiwindup(&vtol_pids[NORTH_VELOCITY], northError, 
	    -guidanceSettings.MaxRollPitch, guidanceSettings.MaxRollPitch, dT) + velocityDesired.North * guidanceSettings.VelocityFeedforward;
	
	// Compute desired east command from velocity error
	eastError = velocityDesired.East - eastVel;
	eastCommand = pid_apply_antiwindup(&vtol_pids[NORTH_VELOCITY], eastError,
	    -guidanceSettings.MaxRollPitch, guidanceSettings.MaxRollPitch, dT) + velocityDesired.East * guidanceSettings.VelocityFeedforward;
	
	// Compute desired down command.  Using NED accel as the damping term
	downError = velocityDesired.Down - downVel;
	// Negative is critical here since throttle is negative with down
	downCommand = -pid_apply_antiwindup(&vtol_pids[DOWN_VELOCITY], downError, -1, 1, dT) +
	    nedAccel.Down * guidanceSettings.VerticalVelPID[VTOLPATHFOLLOWERSETTINGS_VERTICALVELPID_KD];

	// If this setting is zero then the throttle level available when enabled is used for hover:wq
	float used_throttle_offset = (guidanceSettings.HoverThrottle == 0) ? throttleOffset : guidanceSettings.HoverThrottle;
	stabDesired.Throttle = bound_min_max(downCommand + used_throttle_offset, 0, 1);
	
	// Project the north and east command signals into the pitch and roll based on yaw.
	// For this to behave well the craft should move similarly for 5 deg roll versus 5 deg pitch.
	// Notice the inputs are crudely bounded by the anti-winded but if both N and E were
	// saturated and the craft were at 45 degrees that would result in a value greater than
	// the limit, so apply limit again here.
	stabDesired.Pitch = bound_min_max(-northCommand * cosf(attitudeActual.Yaw * DEG2RAD) + 
				      -eastCommand * sinf(attitudeActual.Yaw * DEG2RAD),
				      -guidanceSettings.MaxRollPitch, guidanceSettings.MaxRollPitch);
	stabDesired.Roll = bound_min_max(-northCommand * sinf(attitudeActual.Yaw * DEG2RAD) + 
				     eastCommand * cosf(attitudeActual.Yaw * DEG2RAD),
				     -guidanceSettings.MaxRollPitch, guidanceSettings.MaxRollPitch);
	
	if(guidanceSettings.ThrottleControl == VTOLPATHFOLLOWERSETTINGS_THROTTLECONTROL_FALSE) {
		// For now override throttle with manual control.  Disable at your risk, quad goes to China.
		ManualControlCommandData manualControl;
		ManualControlCommandGet(&manualControl);
		stabDesired.Throttle = manualControl.Throttle;
	}
	
	stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_ROLL] = STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDEPLUS;
	stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_PITCH] = STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDEPLUS;

	float yaw;
	switch(guidanceSettings.YawMode) {
	case VTOLPATHFOLLOWERSETTINGS_YAWMODE_RATE:
		/* This is awkward.  This allows the transmitter to control the yaw while flying navigation */
		ManualControlCommandYawGet(&yaw);
		stabDesired.Yaw = stabSettings.ManualRate[STABILIZATIONSETTINGS_MANUALRATE_YAW] * yaw;      
		stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_YAW] = STABILIZATIONDESIRED_STABILIZATIONMODE_RATE;
		break;
	case VTOLPATHFOLLOWERSETTINGS_YAWMODE_AXISLOCK:
		ManualControlCommandYawGet(&yaw);
		stabDesired.Yaw = stabSettings.ManualRate[STABILIZATIONSETTINGS_MANUALRATE_YAW] * yaw;      
		stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_YAW] = STABILIZATIONDESIRED_STABILIZATIONMODE_AXISLOCK;
		break;
	case VTOLPATHFOLLOWERSETTINGS_YAWMODE_ATTITUDE:
		ManualControlCommandYawGet(&yaw);
		stabDesired.Yaw = stabSettings.YawMax * yaw;      
		stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_YAW] = STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE;
		break;
	case VTOLPATHFOLLOWERSETTINGS_YAWMODE_POI:
		stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_YAW] = STABILIZATIONDESIRED_STABILIZATIONMODE_POI;
		break;
	}
	
	StabilizationDesiredSet(&stabDesired);
}
Esempio n. 5
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/**
 * Module thread, should not return.
 */
static void vtolPathFollowerTask(void *parameters)
{
	SystemSettingsData systemSettings;
	FlightStatusData flightStatus;

	portTickType lastUpdateTime;
	
	VtolPathFollowerSettingsConnectCallback(SettingsUpdatedCb);
	PathDesiredConnectCallback(SettingsUpdatedCb);
	
	VtolPathFollowerSettingsGet(&guidanceSettings);
	PathDesiredGet(&pathDesired);
	
	// Main task loop
	lastUpdateTime = xTaskGetTickCount();
	while (1) {

		// Conditions when this runs:
		// 1. Must have VTOL type airframe
		// 2. Flight mode is PositionHold and PathDesired.Mode is Endpoint  OR
		//    FlightMode is PathPlanner and PathDesired.Mode is Endpoint or Path

		SystemSettingsGet(&systemSettings);
		if ( (systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_VTOL) &&
			(systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_QUADP) &&
			(systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_QUADX) &&
			(systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_HEXA) &&
			(systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_HEXAX) &&
			(systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_HEXACOAX) &&
			(systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_OCTO) &&
			(systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_OCTOV) &&
			(systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_OCTOCOAXP) &&
			(systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_OCTOCOAXX) &&
			(systemSettings.AirframeType != SYSTEMSETTINGS_AIRFRAMETYPE_TRI) )
		{
			AlarmsSet(SYSTEMALARMS_ALARM_PATHFOLLOWER,SYSTEMALARMS_ALARM_WARNING);
			vTaskDelay(1000);
			continue;
		}

		// Continue collecting data if not enough time
		vTaskDelayUntil(&lastUpdateTime, MS2TICKS(guidanceSettings.UpdatePeriod));

		// Convert the accels into the NED frame
		updateNedAccel();
		
		FlightStatusGet(&flightStatus);

		// Check the combinations of flightmode and pathdesired mode
		switch(flightStatus.FlightMode) {
			/* This combination of RETURNTOHOME and HOLDPOSITION looks strange but
			 * is correct.  RETURNTOHOME mode uses HOLDPOSITION with the position
			 * set to home */
			case FLIGHTSTATUS_FLIGHTMODE_RETURNTOHOME:
				if (pathDesired.Mode == PATHDESIRED_MODE_HOLDPOSITION) {
					updateEndpointVelocity();
					updateVtolDesiredAttitude();
				} else {
					AlarmsSet(SYSTEMALARMS_ALARM_PATHFOLLOWER,SYSTEMALARMS_ALARM_ERROR);
				}
				break;
			case FLIGHTSTATUS_FLIGHTMODE_POSITIONHOLD:
				if (pathDesired.Mode == PATHDESIRED_MODE_HOLDPOSITION) {
					updateEndpointVelocity();
					updateVtolDesiredAttitude();
				} else {
					AlarmsSet(SYSTEMALARMS_ALARM_PATHFOLLOWER,SYSTEMALARMS_ALARM_ERROR);
				}
				break;
			case FLIGHTSTATUS_FLIGHTMODE_PATHPLANNER:
				if (pathDesired.Mode == PATHDESIRED_MODE_FLYENDPOINT ||
					pathDesired.Mode == PATHDESIRED_MODE_HOLDPOSITION) {
					updateEndpointVelocity();
					updateVtolDesiredAttitude();
				} else if (pathDesired.Mode == PATHDESIRED_MODE_FLYVECTOR ||
					pathDesired.Mode == PATHDESIRED_MODE_FLYCIRCLELEFT ||
					pathDesired.Mode == PATHDESIRED_MODE_FLYCIRCLERIGHT) {
					updatePathVelocity();
					updateVtolDesiredAttitude();
				} else {
					AlarmsSet(SYSTEMALARMS_ALARM_PATHFOLLOWER,SYSTEMALARMS_ALARM_ERROR);
				}
				break;
			default:

				for (uint32_t i = 0; i < VTOL_PID_NUM; i++)
					pid_zero(&vtol_pids[i]);

				// Track throttle before engaging this mode.  Cheap system ident
				StabilizationDesiredData stabDesired;
				StabilizationDesiredGet(&stabDesired);
				throttleOffset = stabDesired.Throttle;

				break;
		}

		AlarmsClear(SYSTEMALARMS_ALARM_PATHFOLLOWER);

	}
}
Esempio n. 6
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/**
 * Initialise the module, called on startup
 * \returns 0 on success or -1 if initialisation failed
 */
int32_t TxPIDInitialize(void)
{
	bool module_enabled;

#ifdef MODULE_TxPID_BUILTIN
	module_enabled = true;
#else
	uint8_t module_state[MODULESETTINGS_ADMINSTATE_NUMELEM];
	ModuleSettingsAdminStateGet(module_state);
	if (module_state[MODULESETTINGS_ADMINSTATE_TXPID] == MODULESETTINGS_ADMINSTATE_ENABLED) {
		module_enabled = true;
	} else {
		module_enabled = false;
	}
#endif

	if (module_enabled) {

		TxPIDSettingsInitialize();
		AccessoryDesiredInitialize();

		UAVObjEvent ev = {
			.obj = AccessoryDesiredHandle(),
			.instId = 0,
			.event = 0,
		};
		EventPeriodicCallbackCreate(&ev, updatePIDs, SAMPLE_PERIOD_MS);

#if (TELEMETRY_UPDATE_PERIOD_MS != 0)
		// Change StabilizationSettings update rate from OnChange to periodic
		// to prevent telemetry link flooding with frequent updates in case of
		// control channel jitter.
		// Warning: saving to flash with this code active will change the
		// StabilizationSettings update rate permanently. Use Metadata via
		// browser to reset to defaults (telemetryAcked=true, OnChange).
		UAVObjMetadata metadata;
		StabilizationSettingsInitialize();
		StabilizationSettingsGetMetadata(&metadata);
		metadata.telemetryAcked = 0;
		metadata.telemetryUpdateMode = UPDATEMODE_PERIODIC;
		metadata.telemetryUpdatePeriod = TELEMETRY_UPDATE_PERIOD_MS;
		StabilizationSettingsSetMetadata(&metadata);
#endif

		return 0;
	}

	return -1;
}

MODULE_INITCALL(TxPIDInitialize, NULL);

/**
 * Update PIDs callback function
 */
static void updatePIDs(UAVObjEvent* ev)
{
	if (ev->obj != AccessoryDesiredHandle())
		return;

	TxPIDSettingsData inst;
	TxPIDSettingsGet(&inst);

	if (inst.UpdateMode == TXPIDSETTINGS_UPDATEMODE_NEVER)
		return;

	uint8_t armed;
	FlightStatusArmedGet(&armed);
	if ((inst.UpdateMode == TXPIDSETTINGS_UPDATEMODE_WHENARMED) &&
			(armed == FLIGHTSTATUS_ARMED_DISARMED))
		return;

	StabilizationSettingsData stab;
	StabilizationSettingsGet(&stab);

#ifdef UAVOBJ_INIT_vtolpathfollowersettings
	VtolPathFollowerSettingsData vtolPathFollowerSettingsData;
	// Check to make sure the settings UAVObject has been instantiated
	if (VtolPathFollowerSettingsHandle()) {
		VtolPathFollowerSettingsGet(&vtolPathFollowerSettingsData);
	}

	bool vtolPathFollowerSettingsNeedsUpdate = false;
#endif

	AccessoryDesiredData accessory;

	bool stabilizationSettingsNeedsUpdate = false;

	// Loop through every enabled instance
	for (uint8_t i = 0; i < TXPIDSETTINGS_PIDS_NUMELEM; i++) {
		if (inst.PIDs[i] != TXPIDSETTINGS_PIDS_DISABLED) {

			float value;
			if (inst.Inputs[i] == TXPIDSETTINGS_INPUTS_THROTTLE) {
				ManualControlCommandThrottleGet(&value);
				value = scale(value,
						inst.ThrottleRange[TXPIDSETTINGS_THROTTLERANGE_MIN],
						inst.ThrottleRange[TXPIDSETTINGS_THROTTLERANGE_MAX],
						inst.MinPID[i], inst.MaxPID[i]);
			} else if (AccessoryDesiredInstGet(inst.Inputs[i] - TXPIDSETTINGS_INPUTS_ACCESSORY0, &accessory) == 0) {
				value = scale(accessory.AccessoryVal, -1.0, 1.0, inst.MinPID[i], inst.MaxPID[i]);
			} else {
				continue;
			}

			switch (inst.PIDs[i]) {
			case TXPIDSETTINGS_PIDS_ROLLRATEKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollRatePID[STABILIZATIONSETTINGS_ROLLRATEPID_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLRATEKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollRatePID[STABILIZATIONSETTINGS_ROLLRATEPID_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLRATEKD:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollRatePID[STABILIZATIONSETTINGS_ROLLRATEPID_KD], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLRATEILIMIT:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollRatePID[STABILIZATIONSETTINGS_ROLLRATEPID_ILIMIT], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLATTITUDEKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollPI[STABILIZATIONSETTINGS_ROLLPI_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLATTITUDEKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollPI[STABILIZATIONSETTINGS_ROLLPI_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLATTITUDEILIMIT:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollPI[STABILIZATIONSETTINGS_ROLLPI_ILIMIT], value);
				break;
			case TXPIDSETTINGS_PIDS_PITCHRATEKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchRatePID[STABILIZATIONSETTINGS_PITCHRATEPID_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_PITCHRATEKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchRatePID[STABILIZATIONSETTINGS_PITCHRATEPID_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_PITCHRATEKD:
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchRatePID[STABILIZATIONSETTINGS_PITCHRATEPID_KD], value);
				break;
			case TXPIDSETTINGS_PIDS_PITCHRATEILIMIT:
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchRatePID[STABILIZATIONSETTINGS_PITCHRATEPID_ILIMIT], value);
				break;
			case TXPIDSETTINGS_PIDS_PITCHATTITUDEKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchPI[STABILIZATIONSETTINGS_PITCHPI_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_PITCHATTITUDEKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchPI[STABILIZATIONSETTINGS_PITCHPI_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_PITCHATTITUDEILIMIT:
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchPI[STABILIZATIONSETTINGS_PITCHPI_ILIMIT], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLPITCHRATEKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollRatePID[STABILIZATIONSETTINGS_ROLLRATEPID_KP], value);
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchRatePID[STABILIZATIONSETTINGS_PITCHRATEPID_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLPITCHRATEKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollRatePID[STABILIZATIONSETTINGS_ROLLRATEPID_KI], value);
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchRatePID[STABILIZATIONSETTINGS_PITCHRATEPID_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLPITCHRATEKD:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollRatePID[STABILIZATIONSETTINGS_ROLLRATEPID_KD], value);
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchRatePID[STABILIZATIONSETTINGS_PITCHRATEPID_KD], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLPITCHRATEILIMIT:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollRatePID[STABILIZATIONSETTINGS_ROLLRATEPID_ILIMIT], value);
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchRatePID[STABILIZATIONSETTINGS_PITCHRATEPID_ILIMIT], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLPITCHATTITUDEKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollPI[STABILIZATIONSETTINGS_ROLLPI_KP], value);
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchPI[STABILIZATIONSETTINGS_PITCHPI_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLPITCHATTITUDEKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollPI[STABILIZATIONSETTINGS_ROLLPI_KI], value);
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchPI[STABILIZATIONSETTINGS_PITCHPI_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLPITCHATTITUDEILIMIT:
				stabilizationSettingsNeedsUpdate |= update(&stab.RollPI[STABILIZATIONSETTINGS_ROLLPI_ILIMIT], value);
				stabilizationSettingsNeedsUpdate |= update(&stab.PitchPI[STABILIZATIONSETTINGS_PITCHPI_ILIMIT], value);
				break;
			case TXPIDSETTINGS_PIDS_YAWRATEKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.YawRatePID[STABILIZATIONSETTINGS_YAWRATEPID_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_YAWRATEKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.YawRatePID[STABILIZATIONSETTINGS_YAWRATEPID_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_YAWRATEKD:
				stabilizationSettingsNeedsUpdate |= update(&stab.YawRatePID[STABILIZATIONSETTINGS_YAWRATEPID_KD], value);
				break;
			case TXPIDSETTINGS_PIDS_YAWRATEILIMIT:
				stabilizationSettingsNeedsUpdate |= update(&stab.YawRatePID[STABILIZATIONSETTINGS_YAWRATEPID_ILIMIT], value);
				break;
			case TXPIDSETTINGS_PIDS_YAWATTITUDEKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.YawPI[STABILIZATIONSETTINGS_YAWPI_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_YAWATTITUDEKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.YawPI[STABILIZATIONSETTINGS_YAWPI_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_YAWATTITUDEILIMIT:
				stabilizationSettingsNeedsUpdate |= update(&stab.YawPI[STABILIZATIONSETTINGS_YAWPI_ILIMIT], value);
				break;
			case TXPIDSETTINGS_PIDS_GYROCUTOFF:
				stabilizationSettingsNeedsUpdate |= update(&stab.GyroCutoff, value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLVBARSENSITIVITY:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarSensitivity[STABILIZATIONSETTINGS_VBARSENSITIVITY_ROLL], value);
				break;
			case TXPIDSETTINGS_PIDS_PITCHVBARSENSITIVITY:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarSensitivity[STABILIZATIONSETTINGS_VBARSENSITIVITY_PITCH], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLPITCHVBARSENSITIVITY:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarSensitivity[STABILIZATIONSETTINGS_VBARSENSITIVITY_ROLL], value);
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarSensitivity[STABILIZATIONSETTINGS_VBARSENSITIVITY_PITCH], value);
				break;
			
			case TXPIDSETTINGS_PIDS_YAWVBARSENSITIVITY:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarSensitivity[STABILIZATIONSETTINGS_VBARSENSITIVITY_YAW], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLVBARKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarRollPID[STABILIZATIONSETTINGS_VBARROLLPID_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLVBARKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarRollPID[STABILIZATIONSETTINGS_VBARROLLPID_KI], value);
				break;	
			case TXPIDSETTINGS_PIDS_ROLLVBARKD:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarRollPID[STABILIZATIONSETTINGS_VBARROLLPID_KD], value);
				break;
			case TXPIDSETTINGS_PIDS_PITCHVBARKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarPitchPID[STABILIZATIONSETTINGS_VBARPITCHPID_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_PITCHVBARKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarPitchPID[STABILIZATIONSETTINGS_VBARPITCHPID_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_PITCHVBARKD:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarPitchPID[STABILIZATIONSETTINGS_VBARPITCHPID_KD], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLPITCHVBARKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarRollPID[STABILIZATIONSETTINGS_VBARROLLPID_KP], value);
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarPitchPID[STABILIZATIONSETTINGS_VBARPITCHPID_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLPITCHVBARKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarRollPID[STABILIZATIONSETTINGS_VBARROLLPID_KI], value);
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarPitchPID[STABILIZATIONSETTINGS_VBARPITCHPID_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_ROLLPITCHVBARKD:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarRollPID[STABILIZATIONSETTINGS_VBARROLLPID_KD], value);
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarPitchPID[STABILIZATIONSETTINGS_VBARPITCHPID_KD], value);
				break;
			case TXPIDSETTINGS_PIDS_YAWVBARKP:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarYawPID[STABILIZATIONSETTINGS_VBARYAWPID_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_YAWVBARKI:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarYawPID[STABILIZATIONSETTINGS_VBARYAWPID_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_YAWVBARKD:
				stabilizationSettingsNeedsUpdate |= update(&stab.VbarYawPID[STABILIZATIONSETTINGS_VBARYAWPID_KD], value);
				break;
#ifdef UAVOBJ_INIT_vtolpathfollowersettings
			case TXPIDSETTINGS_PIDS_HORIZONTALPOSKP:
				vtolPathFollowerSettingsNeedsUpdate |= update(&vtolPathFollowerSettingsData.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_HORIZONTALPOSKI:
				vtolPathFollowerSettingsNeedsUpdate |= update(&vtolPathFollowerSettingsData.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_HORIZONTALPOSILIMIT:
				vtolPathFollowerSettingsNeedsUpdate |= update(&vtolPathFollowerSettingsData.HorizontalPosPI[VTOLPATHFOLLOWERSETTINGS_HORIZONTALPOSPI_ILIMIT], value);
				break;
			case TXPIDSETTINGS_PIDS_HORIZONTALVELKP:
				vtolPathFollowerSettingsNeedsUpdate |= update(&vtolPathFollowerSettingsData.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KP], value);
				break;
			case TXPIDSETTINGS_PIDS_HORIZONTALVELKI:
				vtolPathFollowerSettingsNeedsUpdate |= update(&vtolPathFollowerSettingsData.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KI], value);
				break;
			case TXPIDSETTINGS_PIDS_HORIZONTALVELKD:
				vtolPathFollowerSettingsNeedsUpdate |= update(&vtolPathFollowerSettingsData.HorizontalVelPID[VTOLPATHFOLLOWERSETTINGS_HORIZONTALVELPID_KD], value);
				break;
#endif /* UAVOBJ_INIT_vtolpathfollowersettings */
			default:
				// Previously this would assert.  But now the
				// object may be missing and it's not worth a
				// crash.
				break;
			}
		}
	}

	// Update UAVOs, if necessary
	if (stabilizationSettingsNeedsUpdate) {
		StabilizationSettingsSet(&stab);
	}

#ifdef UAVOBJ_INIT_vtolpathfollowersettings
	if (vtolPathFollowerSettingsNeedsUpdate) {
		// Check to make sure the settings UAVObject has been instantiated
		if (VtolPathFollowerSettingsHandle()) {
			VtolPathFollowerSettingsSet(&vtolPathFollowerSettingsData);
		}
	}
#endif
}

/**
 * Scales input val from [inMin..inMax] range to [outMin..outMax].
 * If val is out of input range (inMin <= inMax), it will be bound.
 * (outMin > outMax) is ok, in that case output will be decreasing.
 *
 * \returns scaled value
 */
static float scale(float val, float inMin, float inMax, float outMin, float outMax)
{
	// bound input value
	if (val > inMax) val = inMax;
	if (val < inMin) val = inMin;

	// normalize input value to [0..1]
	if (inMax <= inMin)
		val = 0.0;
	else
		val = (val - inMin) / (inMax - inMin);

	// update output bounds
	if (outMin > outMax) {
		float t = outMin;
		outMin = outMax;
		outMax = t;
		val = 1.0f - val;
	}

	return (outMax - outMin) * val + outMin;
}

/**
 * Updates var using val if needed.
 * \returns 1 if updated, 0 otherwise
 */
static bool update(float *var, float val)
{
	if (*var != val) {
		*var = val;
		return true;
	}
	return false;
}