예제 #1
0
파일: sensors.c 프로젝트: Gussy/TauLabs
static void simulateModelAgnostic()
{
	float Rbe[3][3];
	float q[4];

	// Simulate accels based on current attitude
	AttitudeActualData attitudeActual;
	AttitudeActualGet(&attitudeActual);
	q[0] = attitudeActual.q1;
	q[1] = attitudeActual.q2;
	q[2] = attitudeActual.q3;
	q[3] = attitudeActual.q4;
	Quaternion2R(q,Rbe);

	AccelsData accelsData; // Skip get as we set all the fields
	accelsData.x = -GRAVITY * Rbe[0][2];
	accelsData.y = -GRAVITY * Rbe[1][2];
	accelsData.z = -GRAVITY * Rbe[2][2];
	accelsData.temperature = 30;
	AccelsSet(&accelsData);

	RateDesiredData rateDesired;
	RateDesiredGet(&rateDesired);

	GyrosData gyrosData; // Skip get as we set all the fields
	gyrosData.x = rateDesired.Roll + rand_gauss();
	gyrosData.y = rateDesired.Pitch + rand_gauss();
	gyrosData.z = rateDesired.Yaw + rand_gauss();

	// Apply bias correction to the gyros
	GyrosBiasData gyrosBias;
	GyrosBiasGet(&gyrosBias);
	gyrosData.x += gyrosBias.x;
	gyrosData.y += gyrosBias.y;
	gyrosData.z += gyrosBias.z;

	GyrosSet(&gyrosData);

	BaroAltitudeData baroAltitude;
	BaroAltitudeGet(&baroAltitude);
	baroAltitude.Altitude = 1;
	BaroAltitudeSet(&baroAltitude);

	GPSPositionData gpsPosition;
	GPSPositionGet(&gpsPosition);
	gpsPosition.Latitude = 0;
	gpsPosition.Longitude = 0;
	gpsPosition.Altitude = 0;
	GPSPositionSet(&gpsPosition);

	// Because most crafts wont get enough information from gravity to zero yaw gyro, we try
	// and make it average zero (weakly)
	MagnetometerData mag;
	mag.x = 400;
	mag.y = 0;
	mag.z = 800;
	MagnetometerSet(&mag);
}
예제 #2
0
/**
 * Module task
 */
static void stabilizationTask(void* parameters)
{
	portTickType lastSysTime;
	portTickType thisSysTime;
	UAVObjEvent ev;


	ActuatorDesiredData actuatorDesired;
	StabilizationDesiredData stabDesired;
	RateDesiredData rateDesired;
	AttitudeActualData attitudeActual;
	AttitudeRawData attitudeRaw;
	SystemSettingsData systemSettings;
	FlightStatusData flightStatus;

	SettingsUpdatedCb((UAVObjEvent *) NULL);

	// Main task loop
	lastSysTime = xTaskGetTickCount();
	ZeroPids();
	while(1) {
		PIOS_WDG_UpdateFlag(PIOS_WDG_STABILIZATION);

		// Wait until the AttitudeRaw object is updated, if a timeout then go to failsafe
		if ( xQueueReceive(queue, &ev, FAILSAFE_TIMEOUT_MS / portTICK_RATE_MS) != pdTRUE )
		{
			AlarmsSet(SYSTEMALARMS_ALARM_STABILIZATION,SYSTEMALARMS_ALARM_WARNING);
			continue;
		}

		// Check how long since last update
		thisSysTime = xTaskGetTickCount();
		if(thisSysTime > lastSysTime) // reuse dt in case of wraparound
			dT = (thisSysTime - lastSysTime) / portTICK_RATE_MS / 1000.0f;
		lastSysTime = thisSysTime;

		FlightStatusGet(&flightStatus);
		StabilizationDesiredGet(&stabDesired);
		AttitudeActualGet(&attitudeActual);
		AttitudeRawGet(&attitudeRaw);
		RateDesiredGet(&rateDesired);
		SystemSettingsGet(&systemSettings);

#if defined(PIOS_QUATERNION_STABILIZATION)
		// Quaternion calculation of error in each axis.  Uses more memory.
		float rpy_desired[3];
		float q_desired[4];
		float q_error[4];
		float local_error[3];

		// Essentially zero errors for anything in rate or none
		if(stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_ROLL] == STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE)
			rpy_desired[0] = stabDesired.Roll;
		else
			rpy_desired[0] = attitudeActual.Roll;

		if(stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_PITCH] == STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE)
			rpy_desired[1] = stabDesired.Pitch;
		else
			rpy_desired[1] = attitudeActual.Pitch;

		if(stabDesired.StabilizationMode[STABILIZATIONDESIRED_STABILIZATIONMODE_YAW] == STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE)
			rpy_desired[2] = stabDesired.Yaw;
		else
			rpy_desired[2] = attitudeActual.Yaw;

		RPY2Quaternion(rpy_desired, q_desired);
		quat_inverse(q_desired);
		quat_mult(q_desired, &attitudeActual.q1, q_error);
		quat_inverse(q_error);
		Quaternion2RPY(q_error, local_error);

#else
		// Simpler algorithm for CC, less memory
		float local_error[3] = {stabDesired.Roll - attitudeActual.Roll,
			stabDesired.Pitch - attitudeActual.Pitch,
			stabDesired.Yaw - attitudeActual.Yaw};
		local_error[2] = fmod(local_error[2] + 180, 360) - 180;
#endif


		for(uint8_t i = 0; i < MAX_AXES; i++) {
			gyro_filtered[i] = gyro_filtered[i] * gyro_alpha + attitudeRaw.gyros[i] * (1 - gyro_alpha);
		}

		float *attitudeDesiredAxis = &stabDesired.Roll;
		float *actuatorDesiredAxis = &actuatorDesired.Roll;
		float *rateDesiredAxis = &rateDesired.Roll;

		//Calculate desired rate
		for(uint8_t i=0; i< MAX_AXES; i++)
		{
			switch(stabDesired.StabilizationMode[i])
			{
				case STABILIZATIONDESIRED_STABILIZATIONMODE_RATE:
					rateDesiredAxis[i] = attitudeDesiredAxis[i];
					axis_lock_accum[i] = 0;
					break;

				case STABILIZATIONDESIRED_STABILIZATIONMODE_WEAKLEVELING:
				{
					float weak_leveling = local_error[i] * weak_leveling_kp;

					if(weak_leveling > weak_leveling_max)
						weak_leveling = weak_leveling_max;
					if(weak_leveling < -weak_leveling_max)
						weak_leveling = -weak_leveling_max;

					rateDesiredAxis[i] = attitudeDesiredAxis[i] + weak_leveling;

					axis_lock_accum[i] = 0;
					break;
				}
				case STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE:
					rateDesiredAxis[i] = ApplyPid(&pids[PID_ROLL + i], local_error[i]);
					axis_lock_accum[i] = 0;
					break;

				case STABILIZATIONDESIRED_STABILIZATIONMODE_AXISLOCK:
					if(fabs(attitudeDesiredAxis[i]) > max_axislock_rate) {
						// While getting strong commands act like rate mode
						rateDesiredAxis[i] = attitudeDesiredAxis[i];
						axis_lock_accum[i] = 0;
					} else {
						// For weaker commands or no command simply attitude lock (almost) on no gyro change
						axis_lock_accum[i] += (attitudeDesiredAxis[i] - gyro_filtered[i]) * dT;
						if(axis_lock_accum[i] > max_axis_lock)
							axis_lock_accum[i] = max_axis_lock;
						else if(axis_lock_accum[i] < -max_axis_lock)
							axis_lock_accum[i] = -max_axis_lock;

						rateDesiredAxis[i] = ApplyPid(&pids[PID_ROLL + i], axis_lock_accum[i]);
					}
					break;
			}
		}

		uint8_t shouldUpdate = 1;
		RateDesiredSet(&rateDesired);
		ActuatorDesiredGet(&actuatorDesired);
		//Calculate desired command
		for(int8_t ct=0; ct< MAX_AXES; ct++)
		{
			if(rateDesiredAxis[ct] > settings.MaximumRate[ct])
				rateDesiredAxis[ct] = settings.MaximumRate[ct];
			else if(rateDesiredAxis[ct] < -settings.MaximumRate[ct])
				rateDesiredAxis[ct] = -settings.MaximumRate[ct];

			switch(stabDesired.StabilizationMode[ct])
			{
				case STABILIZATIONDESIRED_STABILIZATIONMODE_RATE:
				case STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE:
				case STABILIZATIONDESIRED_STABILIZATIONMODE_AXISLOCK:
				case STABILIZATIONDESIRED_STABILIZATIONMODE_WEAKLEVELING:
				{
					float command = ApplyPid(&pids[PID_RATE_ROLL + ct],  rateDesiredAxis[ct] - gyro_filtered[ct]);
					actuatorDesiredAxis[ct] = bound(command);
					break;
				}
				case STABILIZATIONDESIRED_STABILIZATIONMODE_NONE:
					switch (ct)
				{
					case ROLL:
						actuatorDesiredAxis[ct] = bound(attitudeDesiredAxis[ct]);
						shouldUpdate = 1;
						break;
					case PITCH:
						actuatorDesiredAxis[ct] = bound(attitudeDesiredAxis[ct]);
						shouldUpdate = 1;
						break;
					case YAW:
						actuatorDesiredAxis[ct] = bound(attitudeDesiredAxis[ct]);
						shouldUpdate = 1;
						break;
				}
					break;

			}
		}

		// Save dT
		actuatorDesired.UpdateTime = dT * 1000;

		if(PARSE_FLIGHT_MODE(flightStatus.FlightMode) == FLIGHTMODE_MANUAL)
			shouldUpdate = 0;

		if(shouldUpdate)
		{
			actuatorDesired.Throttle = stabDesired.Throttle;
			if(dT > 15)
				actuatorDesired.NumLongUpdates++;
			ActuatorDesiredSet(&actuatorDesired);
		}

		if(flightStatus.Armed != FLIGHTSTATUS_ARMED_ARMED ||
		   (lowThrottleZeroIntegral && stabDesired.Throttle < 0) ||
		   !shouldUpdate)
		{
			ZeroPids();
		}


		// Clear alarms
		AlarmsClear(SYSTEMALARMS_ALARM_STABILIZATION);
	}
}
예제 #3
0
/**
 * WARNING! This callback executes with critical flight control priority every
 * time a gyroscope update happens do NOT put any time consuming calculations
 * in this loop unless they really have to execute with every gyro update
 */
static void stabilizationInnerloopTask()
{
    // watchdog and error handling
    {
#ifdef PIOS_INCLUDE_WDG
        PIOS_WDG_UpdateFlag(PIOS_WDG_STABILIZATION);
#endif
        bool warn  = false;
        bool error = false;
        bool crit  = false;
        // check if outer loop keeps executing
        if (stabSettings.monitor.rateupdates > -64) {
            stabSettings.monitor.rateupdates--;
        }
        if (stabSettings.monitor.rateupdates < -(2 * OUTERLOOP_SKIPCOUNT)) {
            // warning if rate loop skipped more than 2 execution
            warn = true;
        }
        if (stabSettings.monitor.rateupdates < -(4 * OUTERLOOP_SKIPCOUNT)) {
            // critical if rate loop skipped more than 4 executions
            crit = true;
        }
        // check if gyro keeps updating
        if (stabSettings.monitor.gyroupdates < 1) {
            // error if gyro didn't update at all!
            error = true;
        }
        if (stabSettings.monitor.gyroupdates > 1) {
            // warning if we missed a gyro update
            warn = true;
        }
        if (stabSettings.monitor.gyroupdates > 3) {
            // critical if we missed 3 gyro updates
            crit = true;
        }
        stabSettings.monitor.gyroupdates = 0;

        if (crit) {
            AlarmsSet(SYSTEMALARMS_ALARM_STABILIZATION, SYSTEMALARMS_ALARM_CRITICAL);
        } else if (error) {
            AlarmsSet(SYSTEMALARMS_ALARM_STABILIZATION, SYSTEMALARMS_ALARM_ERROR);
        } else if (warn) {
            AlarmsSet(SYSTEMALARMS_ALARM_STABILIZATION, SYSTEMALARMS_ALARM_WARNING);
        } else {
            AlarmsClear(SYSTEMALARMS_ALARM_STABILIZATION);
        }
    }


    RateDesiredData rateDesired;
    ActuatorDesiredData actuator;
    StabilizationStatusInnerLoopData enabled;
    FlightStatusControlChainData cchain;

    RateDesiredGet(&rateDesired);
    ActuatorDesiredGet(&actuator);
    StabilizationStatusInnerLoopGet(&enabled);
    FlightStatusControlChainGet(&cchain);
    float *rate = &rateDesired.Roll;
    float *actuatorDesiredAxis = &actuator.Roll;
    int t;
    float dT;
    dT = PIOS_DELTATIME_GetAverageSeconds(&timeval);

    for (t = 0; t < AXES; t++) {
        bool reinit = (cast_struct_to_array(enabled, enabled.Roll)[t] != previous_mode[t]);
        previous_mode[t] = cast_struct_to_array(enabled, enabled.Roll)[t];

        if (t < STABILIZATIONSTATUS_INNERLOOP_THRUST) {
            if (reinit) {
                stabSettings.innerPids[t].iAccumulator = 0;
            }
            switch (cast_struct_to_array(enabled, enabled.Roll)[t]) {
            case STABILIZATIONSTATUS_INNERLOOP_VIRTUALFLYBAR:
                stabilization_virtual_flybar(gyro_filtered[t], rate[t], &actuatorDesiredAxis[t], dT, reinit, t, &stabSettings.settings);
                break;
            case STABILIZATIONSTATUS_INNERLOOP_RELAYTUNING:
                rate[t] = boundf(rate[t],
                                 -cast_struct_to_array(stabSettings.stabBank.MaximumRate, stabSettings.stabBank.MaximumRate.Roll)[t],
                                 cast_struct_to_array(stabSettings.stabBank.MaximumRate, stabSettings.stabBank.MaximumRate.Roll)[t]
                                 );
                stabilization_relay_rate(rate[t] - gyro_filtered[t], &actuatorDesiredAxis[t], t, reinit);
                break;
            case STABILIZATIONSTATUS_INNERLOOP_AXISLOCK:
                if (fabsf(rate[t]) > stabSettings.settings.MaxAxisLockRate) {
                    // While getting strong commands act like rate mode
                    axis_lock_accum[t] = 0;
                } else {
                    // For weaker commands or no command simply attitude lock (almost) on no gyro change
                    axis_lock_accum[t] += (rate[t] - gyro_filtered[t]) * dT;
                    axis_lock_accum[t]  = boundf(axis_lock_accum[t], -stabSettings.settings.MaxAxisLock, stabSettings.settings.MaxAxisLock);
                    rate[t] = axis_lock_accum[t] * stabSettings.settings.AxisLockKp;
                }
            // IMPORTANT: deliberately no "break;" here, execution continues with regular RATE control loop to avoid code duplication!
            // keep order as it is, RATE must follow!
            case STABILIZATIONSTATUS_INNERLOOP_RATE:
                // limit rate to maximum configured limits (once here instead of 5 times in outer loop)
                rate[t] = boundf(rate[t],
                                 -cast_struct_to_array(stabSettings.stabBank.MaximumRate, stabSettings.stabBank.MaximumRate.Roll)[t],
                                 cast_struct_to_array(stabSettings.stabBank.MaximumRate, stabSettings.stabBank.MaximumRate.Roll)[t]
                                 );
                actuatorDesiredAxis[t] = pid_apply_setpoint(&stabSettings.innerPids[t], speedScaleFactor, rate[t], gyro_filtered[t], dT);
                break;
            case STABILIZATIONSTATUS_INNERLOOP_DIRECT:
            default:
                actuatorDesiredAxis[t] = rate[t];
                break;
            }
        } else {
            switch (cast_struct_to_array(enabled, enabled.Roll)[t]) {
            case STABILIZATIONSTATUS_INNERLOOP_CRUISECONTROL:
                actuatorDesiredAxis[t] = cruisecontrol_apply_factor(rate[t]);
                break;
            case STABILIZATIONSTATUS_INNERLOOP_DIRECT:
            default:
                actuatorDesiredAxis[t] = rate[t];
                break;
            }
        }

        actuatorDesiredAxis[t] = boundf(actuatorDesiredAxis[t], -1.0f, 1.0f);
    }

    actuator.UpdateTime = dT * 1000;

    if (cchain.Stabilization == FLIGHTSTATUS_CONTROLCHAIN_TRUE) {
        ActuatorDesiredSet(&actuator);
    } else {
        // Force all axes to reinitialize when engaged
        for (t = 0; t < AXES; t++) {
            previous_mode[t] = 255;
        }
    }
    {
        uint8_t armed;
        FlightStatusArmedGet(&armed);
        float throttleDesired;
        ManualControlCommandThrottleGet(&throttleDesired);
        if (armed != FLIGHTSTATUS_ARMED_ARMED ||
            ((stabSettings.settings.LowThrottleZeroIntegral == STABILIZATIONSETTINGS_LOWTHROTTLEZEROINTEGRAL_TRUE) && throttleDesired < 0)) {
            // Force all axes to reinitialize when engaged
            for (t = 0; t < AXES; t++) {
                previous_mode[t] = 255;
            }
        }
    }
    PIOS_CALLBACKSCHEDULER_Schedule(callbackHandle, FAILSAFE_TIMEOUT_MS, CALLBACK_UPDATEMODE_LATER);
}
예제 #4
0
파일: sensors.c 프로젝트: Gussy/TauLabs
/**
 * This method performs a simple simulation of a car
 * 
 * It takes in the ActuatorDesired command to rotate the aircraft and performs
 * a simple kinetic model where the throttle increases the energy and drag decreases
 * it.  Changing altitude moves energy from kinetic to potential.
 *
 * 1. Update attitude based on ActuatorDesired
 * 2. Update position based on velocity
 */
static void simulateModelCar()
{
	static double pos[3] = {0,0,0};
	static double vel[3] = {0,0,0};
	static double ned_accel[3] = {0,0,0};
	static float q[4] = {1,0,0,0};
	static float rpy[3] = {0,0,0}; // Low pass filtered actuator
	static float baro_offset = 0.0f;
	float Rbe[3][3];
	
	const float ACTUATOR_ALPHA = 0.8;
	const float MAX_THRUST = 9.81 * 0.5;
	const float K_FRICTION = 0.2;
	const float GPS_PERIOD = 0.1;
	const float MAG_PERIOD = 1.0 / 75.0;
	const float BARO_PERIOD = 1.0 / 20.0;
	
	static uint32_t last_time;
	
	float dT = (PIOS_DELAY_DiffuS(last_time) / 1e6);
	if(dT < 1e-3)
		dT = 2e-3;
	last_time = PIOS_DELAY_GetRaw();
	
	FlightStatusData flightStatus;
	FlightStatusGet(&flightStatus);
	ActuatorDesiredData actuatorDesired;
	ActuatorDesiredGet(&actuatorDesired);
	
	float thrust = (flightStatus.Armed == FLIGHTSTATUS_ARMED_ARMED) ? actuatorDesired.Throttle * MAX_THRUST : 0;
	if (thrust < 0)
		thrust = 0;
	
	if (thrust != thrust)
		thrust = 0;
	
	//	float control_scaling = thrust * thrustToDegs;
	//	// In rad/s
	//	rpy[0] = control_scaling * actuatorDesired.Roll * (1 - ACTUATOR_ALPHA) + rpy[0] * ACTUATOR_ALPHA;
	//	rpy[1] = control_scaling * actuatorDesired.Pitch * (1 - ACTUATOR_ALPHA) + rpy[1] * ACTUATOR_ALPHA;
	//	rpy[2] = control_scaling * actuatorDesired.Yaw * (1 - ACTUATOR_ALPHA) + rpy[2] * ACTUATOR_ALPHA;
	//	
	//	GyrosData gyrosData; // Skip get as we set all the fields
	//	gyrosData.x = rpy[0] * 180 / M_PI + rand_gauss();
	//	gyrosData.y = rpy[1] * 180 / M_PI + rand_gauss();
	//	gyrosData.z = rpy[2] * 180 / M_PI + rand_gauss();
	
	/**** 1. Update attitude ****/
	RateDesiredData rateDesired;
	RateDesiredGet(&rateDesired);
	
	// Need to get roll angle for easy cross coupling
	AttitudeActualData attitudeActual;
	AttitudeActualGet(&attitudeActual);

	rpy[0] = 0; // cannot roll
	rpy[1] = 0; // cannot pitch
	rpy[2] = (flightStatus.Armed == FLIGHTSTATUS_ARMED_ARMED) * rateDesired.Yaw * (1 - ACTUATOR_ALPHA) + rpy[2] * ACTUATOR_ALPHA;
	

	GyrosData gyrosData; // Skip get as we set all the fields
	gyrosData.x = rpy[0] + rand_gauss();
	gyrosData.y = rpy[1] + rand_gauss();
	gyrosData.z = rpy[2] + rand_gauss();
	GyrosSet(&gyrosData);
	
	// Predict the attitude forward in time
	float qdot[4];
	qdot[0] = (-q[1] * rpy[0] - q[2] * rpy[1] - q[3] * rpy[2]) * dT * DEG2RAD / 2;
	qdot[1] = (q[0] * rpy[0] - q[3] * rpy[1] + q[2] * rpy[2]) * dT * DEG2RAD / 2;
	qdot[2] = (q[3] * rpy[0] + q[0] * rpy[1] - q[1] * rpy[2]) * dT * DEG2RAD / 2;
	qdot[3] = (-q[2] * rpy[0] + q[1] * rpy[1] + q[0] * rpy[2]) * dT * DEG2RAD / 2;
	
	// Take a time step
	q[0] = q[0] + qdot[0];
	q[1] = q[1] + qdot[1];
	q[2] = q[2] + qdot[2];
	q[3] = q[3] + qdot[3];
	
	float qmag = sqrtf(q[0]*q[0] + q[1]*q[1] + q[2]*q[2] + q[3]*q[3]);
	q[0] = q[0] / qmag;
	q[1] = q[1] / qmag;
	q[2] = q[2] / qmag;
	q[3] = q[3] / qmag;
	
	if(overideAttitude){
		AttitudeActualData attitudeActual;
		AttitudeActualGet(&attitudeActual);
		attitudeActual.q1 = q[0];
		attitudeActual.q2 = q[1];
		attitudeActual.q3 = q[2];
		attitudeActual.q4 = q[3];
		AttitudeActualSet(&attitudeActual);
	}
	
	/**** 2. Update position based on velocity ****/
	// Rbe takes a vector from body to earth.  If we take (1,0,0)^T through this and then dot with airspeed
	// we get forward airspeed		
	Quaternion2R(q,Rbe);

	double groundspeed[3] = {vel[0], vel[1], vel[2] };
	double forwardSpeed = Rbe[0][0] * groundspeed[0] + Rbe[0][1] * groundspeed[1] + Rbe[0][2] * groundspeed[2];
	double sidewaysSpeed = Rbe[1][0] * groundspeed[0] + Rbe[1][1] * groundspeed[1] + Rbe[1][2] * groundspeed[2];

	/* Compute aerodynamic forces in body referenced frame.  Later use more sophisticated equations  */
	/* TODO: This should become more accurate.  Use the force equations to calculate lift from the   */
	/* various surfaces based on AoA and airspeed.  From that compute torques and forces.  For later */
	double forces[3]; // X, Y, Z
	forces[0] = thrust - forwardSpeed * K_FRICTION;         // Friction is applied in all directions in NED
	forces[1] = 0 - sidewaysSpeed * K_FRICTION * 100;      // No side slip
	forces[2] = 0;
	
	// Negate force[2] as NED defines down as possitive, aircraft convention is Z up is positive (?)
	ned_accel[0] = forces[0] * Rbe[0][0] + forces[1] * Rbe[1][0] - forces[2] * Rbe[2][0];
	ned_accel[1] = forces[0] * Rbe[0][1] + forces[1] * Rbe[1][1] - forces[2] * Rbe[2][1];
	ned_accel[2] = 0;

	// Apply acceleration based on velocity
	ned_accel[0] -= K_FRICTION * (vel[0]);
	ned_accel[1] -= K_FRICTION * (vel[1]);
	
	// Predict the velocity forward in time
	vel[0] = vel[0] + ned_accel[0] * dT;
	vel[1] = vel[1] + ned_accel[1] * dT;
	vel[2] = vel[2] + ned_accel[2] * dT;
	
	// Predict the position forward in time
	pos[0] = pos[0] + vel[0] * dT;
	pos[1] = pos[1] + vel[1] * dT;
	pos[2] = pos[2] + vel[2] * dT;
	
	// Simulate hitting ground
	if(pos[2] > 0) {
		pos[2] = 0;
		vel[2] = 0;
		ned_accel[2] = 0;
	}
	
	// Sensor feels gravity (when not acceleration in ned frame e.g. ned_accel[2] = 0)
	ned_accel[2] -= GRAVITY;
	
	// Transform the accels back in to body frame
	AccelsData accelsData; // Skip get as we set all the fields
	accelsData.x = ned_accel[0] * Rbe[0][0] + ned_accel[1] * Rbe[0][1] + ned_accel[2] * Rbe[0][2] + accel_bias[0];
	accelsData.y = ned_accel[0] * Rbe[1][0] + ned_accel[1] * Rbe[1][1] + ned_accel[2] * Rbe[1][2] + accel_bias[1];
	accelsData.z = ned_accel[0] * Rbe[2][0] + ned_accel[1] * Rbe[2][1] + ned_accel[2] * Rbe[2][2] + accel_bias[2];
	accelsData.temperature = 30;
	AccelsSet(&accelsData);
	
	if(baro_offset == 0) {
		// Hacky initialization
		baro_offset = 50;// * rand_gauss();
	} else {
		// Very small drift process
		baro_offset += rand_gauss() / 100;
	}
	// Update baro periodically	
	static uint32_t last_baro_time = 0;
	if(PIOS_DELAY_DiffuS(last_baro_time) / 1.0e6 > BARO_PERIOD) {
		BaroAltitudeData baroAltitude;
		BaroAltitudeGet(&baroAltitude);
		baroAltitude.Altitude = -pos[2] + baro_offset;
		BaroAltitudeSet(&baroAltitude);
		last_baro_time = PIOS_DELAY_GetRaw();
	}
	
	HomeLocationData homeLocation;
	HomeLocationGet(&homeLocation);
	
	static float gps_vel_drift[3] = {0,0,0};
	gps_vel_drift[0] = gps_vel_drift[0] * 0.65 + rand_gauss() / 5.0;
	gps_vel_drift[1] = gps_vel_drift[1] * 0.65 + rand_gauss() / 5.0;
	gps_vel_drift[2] = gps_vel_drift[2] * 0.65 + rand_gauss() / 5.0;
	
	// Update GPS periodically	
	static uint32_t last_gps_time = 0;
	if(PIOS_DELAY_DiffuS(last_gps_time) / 1.0e6 > GPS_PERIOD) {
		// Use double precision here as simulating what GPS produces
		double T[3];
		T[0] = homeLocation.Altitude+6.378137E6f * DEG2RAD;
		T[1] = cosf(homeLocation.Latitude / 10e6 * DEG2RAD)*(homeLocation.Altitude+6.378137E6) * DEG2RAD;
		T[2] = -1.0;
		
		static float gps_drift[3] = {0,0,0};
		gps_drift[0] = gps_drift[0] * 0.95 + rand_gauss() / 10.0;
		gps_drift[1] = gps_drift[1] * 0.95 + rand_gauss() / 10.0;
		gps_drift[2] = gps_drift[2] * 0.95 + rand_gauss() / 10.0;
		
		GPSPositionData gpsPosition;
		GPSPositionGet(&gpsPosition);
		gpsPosition.Latitude = homeLocation.Latitude + ((pos[0] + gps_drift[0]) / T[0] * 10.0e6);
		gpsPosition.Longitude = homeLocation.Longitude + ((pos[1] + gps_drift[1])/ T[1] * 10.0e6);
		gpsPosition.Altitude = homeLocation.Altitude + ((pos[2] + gps_drift[2]) / T[2]);
		gpsPosition.Groundspeed = sqrtf(pow(vel[0] + gps_vel_drift[0],2) + pow(vel[1] + gps_vel_drift[1],2));
		gpsPosition.Heading = 180 / M_PI * atan2f(vel[1] + gps_vel_drift[1],vel[0] + gps_vel_drift[0]);
		gpsPosition.Satellites = 7;
		gpsPosition.PDOP = 1;
		GPSPositionSet(&gpsPosition);
		last_gps_time = PIOS_DELAY_GetRaw();
	}
	
	// Update GPS Velocity measurements
	static uint32_t last_gps_vel_time = 1000; // Delay by a millisecond
	if(PIOS_DELAY_DiffuS(last_gps_vel_time) / 1.0e6 > GPS_PERIOD) {
		GPSVelocityData gpsVelocity;
		GPSVelocityGet(&gpsVelocity);
		gpsVelocity.North = vel[0] + gps_vel_drift[0];
		gpsVelocity.East = vel[1] + gps_vel_drift[1];
		gpsVelocity.Down = vel[2] + gps_vel_drift[2];
		GPSVelocitySet(&gpsVelocity);
		last_gps_vel_time = PIOS_DELAY_GetRaw();
	}
	
	// Update mag periodically
	static uint32_t last_mag_time = 0;
	if(PIOS_DELAY_DiffuS(last_mag_time) / 1.0e6 > MAG_PERIOD) {
		MagnetometerData mag;
		mag.x = 100+homeLocation.Be[0] * Rbe[0][0] + homeLocation.Be[1] * Rbe[0][1] + homeLocation.Be[2] * Rbe[0][2];
		mag.y = 100+homeLocation.Be[0] * Rbe[1][0] + homeLocation.Be[1] * Rbe[1][1] + homeLocation.Be[2] * Rbe[1][2];
		mag.z = 100+homeLocation.Be[0] * Rbe[2][0] + homeLocation.Be[1] * Rbe[2][1] + homeLocation.Be[2] * Rbe[2][2];
		magOffsetEstimation(&mag);
		MagnetometerSet(&mag);
		last_mag_time = PIOS_DELAY_GetRaw();
	}
	
	AttitudeSimulatedData attitudeSimulated;
	AttitudeSimulatedGet(&attitudeSimulated);
	attitudeSimulated.q1 = q[0];
	attitudeSimulated.q2 = q[1];
	attitudeSimulated.q3 = q[2];
	attitudeSimulated.q4 = q[3];
	Quaternion2RPY(q,&attitudeSimulated.Roll);
	attitudeSimulated.Position[0] = pos[0];
	attitudeSimulated.Position[1] = pos[1];
	attitudeSimulated.Position[2] = pos[2];
	attitudeSimulated.Velocity[0] = vel[0];
	attitudeSimulated.Velocity[1] = vel[1];
	attitudeSimulated.Velocity[2] = vel[2];
	AttitudeSimulatedSet(&attitudeSimulated);
}
예제 #5
0
파일: sensors.c 프로젝트: Gussy/TauLabs
static void simulateModelQuadcopter()
{
	static double pos[3] = {0,0,0};
	static double vel[3] = {0,0,0};
	static double ned_accel[3] = {0,0,0};
	static float q[4] = {1,0,0,0};
	static float rpy[3] = {0,0,0}; // Low pass filtered actuator
	static float baro_offset = 0.0f;
	static float temperature = 20;
	float Rbe[3][3];
	
	const float ACTUATOR_ALPHA = 0.8;
	const float MAX_THRUST = GRAVITY * 2;
	const float K_FRICTION = 1;
	const float GPS_PERIOD = 0.1;
	const float MAG_PERIOD = 1.0 / 75.0;
	const float BARO_PERIOD = 1.0 / 20.0;
	
	static uint32_t last_time;
	
	float dT = (PIOS_DELAY_DiffuS(last_time) / 1e6);
	if(dT < 1e-3)
		dT = 2e-3;
	last_time = PIOS_DELAY_GetRaw();
	
	FlightStatusData flightStatus;
	FlightStatusGet(&flightStatus);
	ActuatorDesiredData actuatorDesired;
	ActuatorDesiredGet(&actuatorDesired);

	float thrust = (flightStatus.Armed == FLIGHTSTATUS_ARMED_ARMED) ? actuatorDesired.Throttle * MAX_THRUST : 0;
	if (thrust < 0)
		thrust = 0;
	
	if (thrust != thrust)
		thrust = 0;
	
//	float control_scaling = thrust * thrustToDegs;
//	// In rad/s
//	rpy[0] = control_scaling * actuatorDesired.Roll * (1 - ACTUATOR_ALPHA) + rpy[0] * ACTUATOR_ALPHA;
//	rpy[1] = control_scaling * actuatorDesired.Pitch * (1 - ACTUATOR_ALPHA) + rpy[1] * ACTUATOR_ALPHA;
//	rpy[2] = control_scaling * actuatorDesired.Yaw * (1 - ACTUATOR_ALPHA) + rpy[2] * ACTUATOR_ALPHA;
//	
//	GyrosData gyrosData; // Skip get as we set all the fields
//	gyrosData.x = rpy[0] * 180 / M_PI + rand_gauss();
//	gyrosData.y = rpy[1] * 180 / M_PI + rand_gauss();
//	gyrosData.z = rpy[2] * 180 / M_PI + rand_gauss();
	
	RateDesiredData rateDesired;
	RateDesiredGet(&rateDesired);
	
	rpy[0] = (flightStatus.Armed == FLIGHTSTATUS_ARMED_ARMED) * rateDesired.Roll * (1 - ACTUATOR_ALPHA) + rpy[0] * ACTUATOR_ALPHA;
	rpy[1] = (flightStatus.Armed == FLIGHTSTATUS_ARMED_ARMED) * rateDesired.Pitch * (1 - ACTUATOR_ALPHA) + rpy[1] * ACTUATOR_ALPHA;
	rpy[2] = (flightStatus.Armed == FLIGHTSTATUS_ARMED_ARMED) * rateDesired.Yaw * (1 - ACTUATOR_ALPHA) + rpy[2] * ACTUATOR_ALPHA;
	

	temperature = 20;
	GyrosData gyrosData; // Skip get as we set all the fields
	gyrosData.x = rpy[0] + rand_gauss() + (temperature - 20) * 1 + powf(temperature - 20,2) * 0.11; // - powf(temperature - 20,3) * 0.05;;
	gyrosData.y = rpy[1] + rand_gauss() + (temperature - 20) * 1 + powf(temperature - 20,2) * 0.11;;
	gyrosData.z = rpy[2] + rand_gauss() + (temperature - 20) * 1 + powf(temperature - 20,2) * 0.11;;
	gyrosData.temperature = temperature;
	GyrosSet(&gyrosData);
	
	// Predict the attitude forward in time
	float qdot[4];
	qdot[0] = (-q[1] * rpy[0] - q[2] * rpy[1] - q[3] * rpy[2]) * dT * DEG2RAD / 2;
	qdot[1] = (q[0] * rpy[0] - q[3] * rpy[1] + q[2] * rpy[2]) * dT * DEG2RAD / 2;
	qdot[2] = (q[3] * rpy[0] + q[0] * rpy[1] - q[1] * rpy[2]) * dT * DEG2RAD / 2;
	qdot[3] = (-q[2] * rpy[0] + q[1] * rpy[1] + q[0] * rpy[2]) * dT * DEG2RAD / 2;
	
	// Take a time step
	q[0] = q[0] + qdot[0];
	q[1] = q[1] + qdot[1];
	q[2] = q[2] + qdot[2];
	q[3] = q[3] + qdot[3];
	
	float qmag = sqrtf(q[0]*q[0] + q[1]*q[1] + q[2]*q[2] + q[3]*q[3]);
	q[0] = q[0] / qmag;
	q[1] = q[1] / qmag;
	q[2] = q[2] / qmag;
	q[3] = q[3] / qmag;
	
	if(overideAttitude){
		AttitudeActualData attitudeActual;
		AttitudeActualGet(&attitudeActual);
		attitudeActual.q1 = q[0];
		attitudeActual.q2 = q[1];
		attitudeActual.q3 = q[2];
		attitudeActual.q4 = q[3];
		AttitudeActualSet(&attitudeActual);
	}
	
	static float wind[3] = {0,0,0};
	wind[0] = wind[0] * 0.95 + rand_gauss() / 10.0;
	wind[1] = wind[1] * 0.95 + rand_gauss() / 10.0;
	wind[2] = wind[2] * 0.95 + rand_gauss() / 10.0;
	
	Quaternion2R(q,Rbe);
	// Make thrust negative as down is positive
	ned_accel[0] = -thrust * Rbe[2][0];
	ned_accel[1] = -thrust * Rbe[2][1];
	// Gravity causes acceleration of 9.81 in the down direction
	ned_accel[2] = -thrust * Rbe[2][2] + GRAVITY;
	
	// Apply acceleration based on velocity
	ned_accel[0] -= K_FRICTION * (vel[0] - wind[0]);
	ned_accel[1] -= K_FRICTION * (vel[1] - wind[1]);
	ned_accel[2] -= K_FRICTION * (vel[2] - wind[2]);

	// Predict the velocity forward in time
	vel[0] = vel[0] + ned_accel[0] * dT;
	vel[1] = vel[1] + ned_accel[1] * dT;
	vel[2] = vel[2] + ned_accel[2] * dT;

	// Predict the position forward in time
	pos[0] = pos[0] + vel[0] * dT;
	pos[1] = pos[1] + vel[1] * dT;
	pos[2] = pos[2] + vel[2] * dT;

	// Simulate hitting ground
	if(pos[2] > 0) {
		pos[2] = 0;
		vel[2] = 0;
		ned_accel[2] = 0;
	}
		
	// Sensor feels gravity (when not acceleration in ned frame e.g. ned_accel[2] = 0)
	ned_accel[2] -= 9.81;
	
	// Transform the accels back in to body frame
	AccelsData accelsData; // Skip get as we set all the fields
	accelsData.x = ned_accel[0] * Rbe[0][0] + ned_accel[1] * Rbe[0][1] + ned_accel[2] * Rbe[0][2] + accel_bias[0];
	accelsData.y = ned_accel[0] * Rbe[1][0] + ned_accel[1] * Rbe[1][1] + ned_accel[2] * Rbe[1][2] + accel_bias[1];
	accelsData.z = ned_accel[0] * Rbe[2][0] + ned_accel[1] * Rbe[2][1] + ned_accel[2] * Rbe[2][2] + accel_bias[2];
	accelsData.temperature = 30;
	AccelsSet(&accelsData);

	if(baro_offset == 0) {
		// Hacky initialization
		baro_offset = 50;// * rand_gauss();
	} else {
		// Very small drift process
		baro_offset += rand_gauss() / 100;
	}
	// Update baro periodically	
	static uint32_t last_baro_time = 0;
	if(PIOS_DELAY_DiffuS(last_baro_time) / 1.0e6 > BARO_PERIOD) {
		BaroAltitudeData baroAltitude;
		BaroAltitudeGet(&baroAltitude);
		baroAltitude.Altitude = -pos[2] + baro_offset;
		BaroAltitudeSet(&baroAltitude);
		last_baro_time = PIOS_DELAY_GetRaw();
	}
	
	HomeLocationData homeLocation;
	HomeLocationGet(&homeLocation);

	static float gps_vel_drift[3] = {0,0,0};
	gps_vel_drift[0] = gps_vel_drift[0] * 0.65 + rand_gauss() / 5.0;
	gps_vel_drift[1] = gps_vel_drift[1] * 0.65 + rand_gauss() / 5.0;
	gps_vel_drift[2] = gps_vel_drift[2] * 0.65 + rand_gauss() / 5.0;

	// Update GPS periodically	
	static uint32_t last_gps_time = 0;
	if(PIOS_DELAY_DiffuS(last_gps_time) / 1.0e6 > GPS_PERIOD) {
		// Use double precision here as simulating what GPS produces
		double T[3];
		T[0] = homeLocation.Altitude+6.378137E6f * DEG2RAD;
		T[1] = cosf(homeLocation.Latitude / 10e6 * DEG2RAD)*(homeLocation.Altitude+6.378137E6) * DEG2RAD;
		T[2] = -1.0;
		
		static float gps_drift[3] = {0,0,0};
		gps_drift[0] = gps_drift[0] * 0.95 + rand_gauss() / 10.0;
		gps_drift[1] = gps_drift[1] * 0.95 + rand_gauss() / 10.0;
		gps_drift[2] = gps_drift[2] * 0.95 + rand_gauss() / 10.0;

		GPSPositionData gpsPosition;
		GPSPositionGet(&gpsPosition);
		gpsPosition.Latitude = homeLocation.Latitude + ((pos[0] + gps_drift[0]) / T[0] * 10.0e6);
		gpsPosition.Longitude = homeLocation.Longitude + ((pos[1] + gps_drift[1])/ T[1] * 10.0e6);
		gpsPosition.Altitude = homeLocation.Altitude + ((pos[2] + gps_drift[2]) / T[2]);
		gpsPosition.Groundspeed = sqrtf(pow(vel[0] + gps_vel_drift[0],2) + pow(vel[1] + gps_vel_drift[1],2));
		gpsPosition.Heading = 180 / M_PI * atan2f(vel[1] + gps_vel_drift[1],vel[0] + gps_vel_drift[0]);
		gpsPosition.Satellites = 7;
		gpsPosition.PDOP = 1;
		gpsPosition.Status = GPSPOSITION_STATUS_FIX3D;
		GPSPositionSet(&gpsPosition);
		last_gps_time = PIOS_DELAY_GetRaw();
	}
	
	// Update GPS Velocity measurements
	static uint32_t last_gps_vel_time = 1000; // Delay by a millisecond
	if(PIOS_DELAY_DiffuS(last_gps_vel_time) / 1.0e6 > GPS_PERIOD) {
		GPSVelocityData gpsVelocity;
		GPSVelocityGet(&gpsVelocity);
		gpsVelocity.North = vel[0] + gps_vel_drift[0];
		gpsVelocity.East = vel[1] + gps_vel_drift[1];
		gpsVelocity.Down = vel[2] + gps_vel_drift[2];
		GPSVelocitySet(&gpsVelocity);
		last_gps_vel_time = PIOS_DELAY_GetRaw();
	}

	// Update mag periodically
	static uint32_t last_mag_time = 0;
	if(PIOS_DELAY_DiffuS(last_mag_time) / 1.0e6 > MAG_PERIOD) {
		MagnetometerData mag;
		mag.x = homeLocation.Be[0] * Rbe[0][0] + homeLocation.Be[1] * Rbe[0][1] + homeLocation.Be[2] * Rbe[0][2];
		mag.y = homeLocation.Be[0] * Rbe[1][0] + homeLocation.Be[1] * Rbe[1][1] + homeLocation.Be[2] * Rbe[1][2];
		mag.z = homeLocation.Be[0] * Rbe[2][0] + homeLocation.Be[1] * Rbe[2][1] + homeLocation.Be[2] * Rbe[2][2];

		// Run the offset compensation algorithm from the firmware
		magOffsetEstimation(&mag);

		MagnetometerSet(&mag);
		last_mag_time = PIOS_DELAY_GetRaw();
	}
	
	AttitudeSimulatedData attitudeSimulated;
	AttitudeSimulatedGet(&attitudeSimulated);
	attitudeSimulated.q1 = q[0];
	attitudeSimulated.q2 = q[1];
	attitudeSimulated.q3 = q[2];
	attitudeSimulated.q4 = q[3];
	Quaternion2RPY(q,&attitudeSimulated.Roll);
	attitudeSimulated.Position[0] = pos[0];
	attitudeSimulated.Position[1] = pos[1];
	attitudeSimulated.Position[2] = pos[2];
	attitudeSimulated.Velocity[0] = vel[0];
	attitudeSimulated.Velocity[1] = vel[1];
	attitudeSimulated.Velocity[2] = vel[2];
	AttitudeSimulatedSet(&attitudeSimulated);
}
예제 #6
0
/**
 * Module task
 */
static void stabilizationTask(void* parameters)
{
	UAVObjEvent ev;
	
	uint32_t timeval = PIOS_DELAY_GetRaw();
	
	ActuatorDesiredData actuatorDesired;
	StabilizationDesiredData stabDesired;
	RateDesiredData rateDesired;
	AttitudeActualData attitudeActual;
	GyrosData gyrosData;
	FlightStatusData flightStatus;

	float *stabDesiredAxis = &stabDesired.Roll;
	float *actuatorDesiredAxis = &actuatorDesired.Roll;
	float *rateDesiredAxis = &rateDesired.Roll;
	float horizonRateFraction = 0.0f;

	// Force refresh of all settings immediately before entering main task loop
	SettingsUpdatedCb((UAVObjEvent *) NULL);
	
	// Settings for system identification
	uint32_t iteration = 0;
	const uint32_t SYSTEM_IDENT_PERIOD = 75;
	uint32_t system_ident_timeval = PIOS_DELAY_GetRaw();

	float dT_filtered = 0;

	// Main task loop
	zero_pids();
	while(1) {
		iteration++;

		PIOS_WDG_UpdateFlag(PIOS_WDG_STABILIZATION);
		
		// Wait until the AttitudeRaw object is updated, if a timeout then go to failsafe
		if (PIOS_Queue_Receive(queue, &ev, FAILSAFE_TIMEOUT_MS) != true)
		{
			AlarmsSet(SYSTEMALARMS_ALARM_STABILIZATION,SYSTEMALARMS_ALARM_WARNING);
			continue;
		}
		
		calculate_pids();

		float dT = PIOS_DELAY_DiffuS(timeval) * 1.0e-6f;
		timeval = PIOS_DELAY_GetRaw();
		
		// exponential moving averaging (EMA) of dT to reduce jitter; ~200points
		// to have more or less equivalent noise reduction to a normal N point moving averaging:  alpha = 2 / (N + 1)
		// run it only at the beginning for the first samples, to reduce CPU load, and the value should converge to a constant value

		if (iteration < 100) {
			dT_filtered = dT;
		} else if (iteration < 2000) {
			dT_filtered = 0.01f * dT + (1.0f - 0.01f) * dT_filtered;
		} else if (iteration == 2000) {
			gyro_filter_updated = true;
		}

		if (gyro_filter_updated) {
			if (settings.GyroCutoff < 1.0f) {
				gyro_alpha = 0;
			} else {
				gyro_alpha = expf(-2.0f * (float)(M_PI) *
						settings.GyroCutoff * dT_filtered);
			}

			// Compute time constant for vbar decay term
			if (settings.VbarTau < 0.001f) {
				vbar_decay = 0;
			} else {
				vbar_decay = expf(-dT_filtered / settings.VbarTau);
			}

			gyro_filter_updated = false;
		}

		FlightStatusGet(&flightStatus);
		StabilizationDesiredGet(&stabDesired);
		AttitudeActualGet(&attitudeActual);
		GyrosGet(&gyrosData);
		ActuatorDesiredGet(&actuatorDesired);
#if defined(RATEDESIRED_DIAGNOSTICS)
		RateDesiredGet(&rateDesired);
#endif

		struct TrimmedAttitudeSetpoint {
			float Roll;
			float Pitch;
			float Yaw;
		} trimmedAttitudeSetpoint;
		
		// Mux in level trim values, and saturate the trimmed attitude setpoint.
		trimmedAttitudeSetpoint.Roll = bound_min_max(
			stabDesired.Roll + trimAngles.Roll,
			-settings.RollMax + trimAngles.Roll,
			 settings.RollMax + trimAngles.Roll);
		trimmedAttitudeSetpoint.Pitch = bound_min_max(
			stabDesired.Pitch + trimAngles.Pitch,
			-settings.PitchMax + trimAngles.Pitch,
			 settings.PitchMax + trimAngles.Pitch);
		trimmedAttitudeSetpoint.Yaw = stabDesired.Yaw;

		// For horizon mode we need to compute the desire attitude from an unscaled value and apply the
		// trim offset. Also track the stick with the most deflection to choose rate blending.
		horizonRateFraction = 0.0f;
		if (stabDesired.StabilizationMode[ROLL] == STABILIZATIONDESIRED_STABILIZATIONMODE_HORIZON) {
			trimmedAttitudeSetpoint.Roll = bound_min_max(
				stabDesired.Roll * settings.RollMax + trimAngles.Roll,
				-settings.RollMax + trimAngles.Roll,
				 settings.RollMax + trimAngles.Roll);
			horizonRateFraction = fabsf(stabDesired.Roll);
		}
		if (stabDesired.StabilizationMode[PITCH] == STABILIZATIONDESIRED_STABILIZATIONMODE_HORIZON) {
			trimmedAttitudeSetpoint.Pitch = bound_min_max(
				stabDesired.Pitch * settings.PitchMax + trimAngles.Pitch,
				-settings.PitchMax + trimAngles.Pitch,
				 settings.PitchMax + trimAngles.Pitch);
			horizonRateFraction = MAX(horizonRateFraction, fabsf(stabDesired.Pitch));
		}
		if (stabDesired.StabilizationMode[YAW] == STABILIZATIONDESIRED_STABILIZATIONMODE_HORIZON) {
			trimmedAttitudeSetpoint.Yaw = stabDesired.Yaw * settings.YawMax;
			horizonRateFraction = MAX(horizonRateFraction, fabsf(stabDesired.Yaw));
		}

		// For weak leveling mode the attitude setpoint is the trim value (drifts back towards "0")
		if (stabDesired.StabilizationMode[ROLL] == STABILIZATIONDESIRED_STABILIZATIONMODE_WEAKLEVELING) {
			trimmedAttitudeSetpoint.Roll = trimAngles.Roll;
		}
		if (stabDesired.StabilizationMode[PITCH] == STABILIZATIONDESIRED_STABILIZATIONMODE_WEAKLEVELING) {
			trimmedAttitudeSetpoint.Pitch = trimAngles.Pitch;
		}
		if (stabDesired.StabilizationMode[YAW] == STABILIZATIONDESIRED_STABILIZATIONMODE_WEAKLEVELING) {
			trimmedAttitudeSetpoint.Yaw = 0;
		}

		// Note we divide by the maximum limit here so the fraction ranges from 0 to 1 depending on
		// how much is requested.
		horizonRateFraction = bound_sym(horizonRateFraction, HORIZON_MODE_MAX_BLEND) / HORIZON_MODE_MAX_BLEND;

		// Calculate the errors in each axis. The local error is used in the following modes:
		//  ATTITUDE, HORIZON, WEAKLEVELING
		float local_attitude_error[3];
		local_attitude_error[0] = trimmedAttitudeSetpoint.Roll - attitudeActual.Roll;
		local_attitude_error[1] = trimmedAttitudeSetpoint.Pitch - attitudeActual.Pitch;
		local_attitude_error[2] = trimmedAttitudeSetpoint.Yaw - attitudeActual.Yaw;
		
		// Wrap yaw error to [-180,180]
		local_attitude_error[2] = circular_modulus_deg(local_attitude_error[2]);

		static float gyro_filtered[3];
		gyro_filtered[0] = gyro_filtered[0] * gyro_alpha + gyrosData.x * (1 - gyro_alpha);
		gyro_filtered[1] = gyro_filtered[1] * gyro_alpha + gyrosData.y * (1 - gyro_alpha);
		gyro_filtered[2] = gyro_filtered[2] * gyro_alpha + gyrosData.z * (1 - gyro_alpha);

		// A flag to track which stabilization mode each axis is in
		static uint8_t previous_mode[MAX_AXES] = {255,255,255};
		bool error = false;

		//Run the selected stabilization algorithm on each axis:
		for(uint8_t i=0; i< MAX_AXES; i++)
		{
			// Check whether this axis mode needs to be reinitialized
			bool reinit = (stabDesired.StabilizationMode[i] != previous_mode[i]);
			// The unscaled input (-1,1)
			float *raw_input = &stabDesired.Roll;
			previous_mode[i] = stabDesired.StabilizationMode[i];
			// Apply the selected control law
			switch(stabDesired.StabilizationMode[i])
			{
				case STABILIZATIONDESIRED_STABILIZATIONMODE_RATE:
					if(reinit)
						pids[PID_GROUP_RATE + i].iAccumulator = 0;

					// Store to rate desired variable for storing to UAVO
					rateDesiredAxis[i] = bound_sym(stabDesiredAxis[i], settings.ManualRate[i]);

					// Compute the inner loop
					actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_GROUP_RATE + i],  rateDesiredAxis[i],  gyro_filtered[i], dT);
					actuatorDesiredAxis[i] = bound_sym(actuatorDesiredAxis[i],1.0f);

					break;

			case STABILIZATIONDESIRED_STABILIZATIONMODE_ACROPLUS:
					// this implementation is based on the Openpilot/Librepilot Acro+ flightmode
					// and our existing rate & MWRate flightmodes
					if(reinit)
							pids[PID_GROUP_RATE + i].iAccumulator = 0;

					// The factor for gyro suppression / mixing raw stick input into the output; scaled by raw stick input
					float factor = fabsf(raw_input[i]) * settings.AcroInsanityFactor / 100;

					// Store to rate desired variable for storing to UAVO
					rateDesiredAxis[i] = bound_sym(raw_input[i] * settings.ManualRate[i], settings.ManualRate[i]);

					// Zero integral for aggressive maneuvers, like it is done for MWRate
					if ((i < 2 && fabsf(gyro_filtered[i]) > 150.0f) ||
											(i == 0 && fabsf(raw_input[i]) > 0.2f)) {
							pids[PID_GROUP_RATE + i].iAccumulator = 0;
							pids[PID_GROUP_RATE + i].i = 0;
							}

					// Compute the inner loop
					actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_GROUP_RATE + i], rateDesiredAxis[i], gyro_filtered[i], dT);
					actuatorDesiredAxis[i] = factor * raw_input[i] + (1.0f - factor) * actuatorDesiredAxis[i];
					actuatorDesiredAxis[i] = bound_sym(actuatorDesiredAxis[i], 1.0f);

					break;
			case STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE:
					if(reinit) {
						pids[PID_GROUP_ATT + i].iAccumulator = 0;
						pids[PID_GROUP_RATE + i].iAccumulator = 0;
					}

					// Compute the outer loop
					rateDesiredAxis[i] = pid_apply(&pids[PID_GROUP_ATT + i], local_attitude_error[i], dT);
					rateDesiredAxis[i] = bound_sym(rateDesiredAxis[i], settings.MaximumRate[i]);

					// Compute the inner loop
					actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_GROUP_RATE + i],  rateDesiredAxis[i],  gyro_filtered[i], dT);
					actuatorDesiredAxis[i] = bound_sym(actuatorDesiredAxis[i],1.0f);

					break;

				case STABILIZATIONDESIRED_STABILIZATIONMODE_VIRTUALBAR:
					// Store for debugging output
					rateDesiredAxis[i] = stabDesiredAxis[i];

					// Run a virtual flybar stabilization algorithm on this axis
					stabilization_virtual_flybar(gyro_filtered[i], rateDesiredAxis[i], &actuatorDesiredAxis[i], dT, reinit, i, &pids[PID_GROUP_VBAR + i], &settings);

					break;
				case STABILIZATIONDESIRED_STABILIZATIONMODE_WEAKLEVELING:
				{
					if (reinit)
						pids[PID_GROUP_RATE + i].iAccumulator = 0;

					float weak_leveling = local_attitude_error[i] * weak_leveling_kp;
					weak_leveling = bound_sym(weak_leveling, weak_leveling_max);

					// Compute desired rate as input biased towards leveling
					rateDesiredAxis[i] = stabDesiredAxis[i] + weak_leveling;
					actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_GROUP_RATE + i],  rateDesiredAxis[i],  gyro_filtered[i], dT);
					actuatorDesiredAxis[i] = bound_sym(actuatorDesiredAxis[i],1.0f);

					break;
				}
				case STABILIZATIONDESIRED_STABILIZATIONMODE_AXISLOCK:
					if (reinit)
						pids[PID_GROUP_RATE + i].iAccumulator = 0;

					if (fabsf(stabDesiredAxis[i]) > max_axislock_rate) {
						// While getting strong commands act like rate mode
						rateDesiredAxis[i] = bound_sym(stabDesiredAxis[i], settings.ManualRate[i]);

						// Reset accumulator
						axis_lock_accum[i] = 0;
					} else {
						// For weaker commands or no command simply lock (almost) on no gyro change
						axis_lock_accum[i] += (stabDesiredAxis[i] - gyro_filtered[i]) * dT;
						axis_lock_accum[i] = bound_sym(axis_lock_accum[i], max_axis_lock);

						// Compute the inner loop
						float tmpRateDesired = pid_apply(&pids[PID_GROUP_ATT + i], axis_lock_accum[i], dT);
						rateDesiredAxis[i] = bound_sym(tmpRateDesired, settings.MaximumRate[i]);
					}

					actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_GROUP_RATE + i],  rateDesiredAxis[i],  gyro_filtered[i], dT);
					actuatorDesiredAxis[i] = bound_sym(actuatorDesiredAxis[i],1.0f);

					break;

				case STABILIZATIONDESIRED_STABILIZATIONMODE_HORIZON:
					if(reinit) {
						pids[PID_GROUP_RATE + i].iAccumulator = 0;
					}

					// Do not allow outer loop integral to wind up in this mode since the controller
					// is often disengaged.
					pids[PID_GROUP_ATT + i].iAccumulator = 0;

					// Compute the outer loop for the attitude control
					float rateDesiredAttitude = pid_apply(&pids[PID_GROUP_ATT + i], local_attitude_error[i], dT);
					// Compute the desire rate for a rate control
					float rateDesiredRate = raw_input[i] * settings.ManualRate[i];

					// Blend from one rate to another. The maximum of all stick positions is used for the
					// amount so that when one axis goes completely to rate the other one does too. This
					// prevents doing flips while one axis tries to stay in attitude mode.
					rateDesiredAxis[i] = rateDesiredAttitude * (1.0f-horizonRateFraction) + rateDesiredRate * horizonRateFraction;
					rateDesiredAxis[i] = bound_sym(rateDesiredAxis[i], settings.ManualRate[i]);

					// Compute the inner loop
					actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_GROUP_RATE + i],  rateDesiredAxis[i],  gyro_filtered[i], dT);
					actuatorDesiredAxis[i] = bound_sym(actuatorDesiredAxis[i],1.0f);

					break;

				case STABILIZATIONDESIRED_STABILIZATIONMODE_MWRATE:
				{
					if(reinit) {
						pids[PID_GROUP_MWR + i].iAccumulator = 0;
					}

					/*
					 Conversion from MultiWii PID settings to our units.
						Kp = Kp_mw * 4 / 80 / 500
						Kd = Kd_mw * looptime * 1e-6 * 4 * 3 / 32 / 500
						Ki = Ki_mw * 4 / 125 / 64 / (looptime * 1e-6) / 500

						These values will just be approximate and should help
						you get started.
					*/

					// The unscaled input (-1,1) - note in MW this is from (-500,500)
					float *raw_input = &stabDesired.Roll;

					// dynamic PIDs are scaled both by throttle and stick position
					float scale = (i == 0 || i == 1) ? mwrate_settings.RollPitchRate : mwrate_settings.YawRate;
					float pid_scale = (100.0f - scale * fabsf(raw_input[i])) / 100.0f;
					float dynP8 = pids[PID_GROUP_MWR + i].p * pid_scale;
					float dynD8 = pids[PID_GROUP_MWR + i].d * pid_scale;
					// these terms are used by the integral loop this proportional term is scaled by throttle (this is different than MW
					// that does not apply scale 
					float cfgP8 = pids[PID_GROUP_MWR + i].p;
					float cfgI8 = pids[PID_GROUP_MWR + i].i;

					// Dynamically adjust PID settings
					struct pid mw_pid;
					mw_pid.p = 0;      // use zero Kp here because of strange setpoint. applied later.
					mw_pid.d = dynD8;
					mw_pid.i = cfgI8;
					mw_pid.iLim = pids[PID_GROUP_MWR + i].iLim;
					mw_pid.iAccumulator = pids[PID_GROUP_MWR + i].iAccumulator;
					mw_pid.lastErr = pids[PID_GROUP_MWR + i].lastErr;
					mw_pid.lastDer = pids[PID_GROUP_MWR + i].lastDer;

					// Zero integral for aggressive maneuvers
 					if ((i < 2 && fabsf(gyro_filtered[i]) > 150.0f) ||
 					    (i == 0 && fabsf(raw_input[i]) > 0.2f)) {
						mw_pid.iAccumulator = 0;
						mw_pid.i = 0;
					}

					// Apply controller as if we want zero change, then add stick input afterwards
					actuatorDesiredAxis[i] = pid_apply_setpoint(&mw_pid,  raw_input[i] / cfgP8,  gyro_filtered[i], dT);
					actuatorDesiredAxis[i] += raw_input[i];             // apply input
					actuatorDesiredAxis[i] -= dynP8 * gyro_filtered[i]; // apply Kp term
					actuatorDesiredAxis[i] = bound_sym(actuatorDesiredAxis[i],1.0f);

					// Store PID accumulators for next cycle
					pids[PID_GROUP_MWR + i].iAccumulator = mw_pid.iAccumulator;
					pids[PID_GROUP_MWR + i].lastErr = mw_pid.lastErr;
					pids[PID_GROUP_MWR + i].lastDer = mw_pid.lastDer;
				}
					break;
				case STABILIZATIONDESIRED_STABILIZATIONMODE_SYSTEMIDENT:
					if(reinit) {
						pids[PID_GROUP_ATT + i].iAccumulator = 0;
						pids[PID_GROUP_RATE + i].iAccumulator = 0;
					}

					static uint32_t ident_iteration = 0;
					static float ident_offsets[3] = {0};

					if (PIOS_DELAY_DiffuS(system_ident_timeval) / 1000.0f > SYSTEM_IDENT_PERIOD && SystemIdentHandle()) {
						ident_iteration++;
						system_ident_timeval = PIOS_DELAY_GetRaw();

						SystemIdentData systemIdent;
						SystemIdentGet(&systemIdent);

						const float SCALE_BIAS = 7.1f;
						float roll_scale = expf(SCALE_BIAS - systemIdent.Beta[SYSTEMIDENT_BETA_ROLL]);
						float pitch_scale = expf(SCALE_BIAS - systemIdent.Beta[SYSTEMIDENT_BETA_PITCH]);
						float yaw_scale = expf(SCALE_BIAS - systemIdent.Beta[SYSTEMIDENT_BETA_YAW]);

						if (roll_scale > 0.25f)
							roll_scale = 0.25f;
						if (pitch_scale > 0.25f)
							pitch_scale = 0.25f;
						if (yaw_scale > 0.25f)
							yaw_scale = 0.2f;

						switch(ident_iteration & 0x07) {
							case 0:
								ident_offsets[0] = 0;
								ident_offsets[1] = 0;
								ident_offsets[2] = yaw_scale;
								break;
							case 1:
								ident_offsets[0] = roll_scale;
								ident_offsets[1] = 0;
								ident_offsets[2] = 0;
								break;
							case 2:
								ident_offsets[0] = 0;
								ident_offsets[1] = 0;
								ident_offsets[2] = -yaw_scale;
								break;
							case 3:
								ident_offsets[0] = -roll_scale;
								ident_offsets[1] = 0;
								ident_offsets[2] = 0;
								break;
							case 4:
								ident_offsets[0] = 0;
								ident_offsets[1] = 0;
								ident_offsets[2] = yaw_scale;
								break;
							case 5:
								ident_offsets[0] = 0;
								ident_offsets[1] = pitch_scale;
								ident_offsets[2] = 0;
								break;
							case 6:
								ident_offsets[0] = 0;
								ident_offsets[1] = 0;
								ident_offsets[2] = -yaw_scale;
								break;
							case 7:
								ident_offsets[0] = 0;
								ident_offsets[1] = -pitch_scale;
								ident_offsets[2] = 0;
								break;
						}
					}

					if (i == ROLL || i == PITCH) {
						// Compute the outer loop
						rateDesiredAxis[i] = pid_apply(&pids[PID_GROUP_ATT + i], local_attitude_error[i], dT);
						rateDesiredAxis[i] = bound_sym(rateDesiredAxis[i], settings.MaximumRate[i]);

						// Compute the inner loop
						actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_GROUP_RATE + i],  rateDesiredAxis[i],  gyro_filtered[i], dT);
						actuatorDesiredAxis[i] += ident_offsets[i];
						actuatorDesiredAxis[i] = bound_sym(actuatorDesiredAxis[i],1.0f);
					} else {
						// Get the desired rate. yaw is always in rate mode in system ident.
						rateDesiredAxis[i] = bound_sym(stabDesiredAxis[i], settings.ManualRate[i]);

						// Compute the inner loop only for yaw
						actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_GROUP_RATE + i],  rateDesiredAxis[i],  gyro_filtered[i], dT);
						actuatorDesiredAxis[i] += ident_offsets[i];
						actuatorDesiredAxis[i] = bound_sym(actuatorDesiredAxis[i],1.0f);						
					}

					break;

				case STABILIZATIONDESIRED_STABILIZATIONMODE_COORDINATEDFLIGHT:
					switch (i) {
						case YAW:
							if (reinit) {
								pids[PID_COORDINATED_FLIGHT_YAW].iAccumulator = 0;
								pids[PID_RATE_YAW].iAccumulator = 0;
								axis_lock_accum[YAW] = 0;
							}

							//If we are not in roll attitude mode, trigger an error
							if (stabDesired.StabilizationMode[ROLL] != STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE)
							{
								error = true;
								break ;
							}

							if (fabsf(stabDesired.Yaw) < COORDINATED_FLIGHT_MAX_YAW_THRESHOLD) { //If yaw is within the deadband...
								if (fabsf(stabDesired.Roll) > COORDINATED_FLIGHT_MIN_ROLL_THRESHOLD) { // We're requesting more roll than the threshold
									float accelsDataY;
									AccelsyGet(&accelsDataY);

									//Reset integral if we have changed roll to opposite direction from rudder. This implies that we have changed desired turning direction.
									if ((stabDesired.Roll > 0 && actuatorDesiredAxis[YAW] < 0) ||
											(stabDesired.Roll < 0 && actuatorDesiredAxis[YAW] > 0)){
										pids[PID_COORDINATED_FLIGHT_YAW].iAccumulator = 0;
									}

									// Coordinate flight can simply be seen as ensuring that there is no lateral acceleration in the
									// body frame. As such, we use the (noisy) accelerometer data as our measurement. Ideally, at
									// some point in the future we will estimate acceleration and then we can use the estimated value
									// instead of the measured value.
									float errorSlip = -accelsDataY;

									float command = pid_apply(&pids[PID_COORDINATED_FLIGHT_YAW], errorSlip, dT);
									actuatorDesiredAxis[YAW] = bound_sym(command ,1.0);

									// Reset axis-lock integrals
									pids[PID_RATE_YAW].iAccumulator = 0;
									axis_lock_accum[YAW] = 0;
								} else if (fabsf(stabDesired.Roll) <= COORDINATED_FLIGHT_MIN_ROLL_THRESHOLD) { // We're requesting less roll than the threshold
									// Axis lock on no gyro change
									axis_lock_accum[YAW] += (0 - gyro_filtered[YAW]) * dT;

									rateDesiredAxis[YAW] = pid_apply(&pids[PID_ATT_YAW], axis_lock_accum[YAW], dT);
									rateDesiredAxis[YAW] = bound_sym(rateDesiredAxis[YAW], settings.MaximumRate[YAW]);

									actuatorDesiredAxis[YAW] = pid_apply_setpoint(&pids[PID_RATE_YAW],  rateDesiredAxis[YAW],  gyro_filtered[YAW], dT);
									actuatorDesiredAxis[YAW] = bound_sym(actuatorDesiredAxis[YAW],1.0f);

									// Reset coordinated-flight integral
									pids[PID_COORDINATED_FLIGHT_YAW].iAccumulator = 0;
								}
							} else { //... yaw is outside the deadband. Pass the manual input directly to the actuator.
								actuatorDesiredAxis[YAW] = bound_sym(stabDesiredAxis[YAW], 1.0);

								// Reset all integrals
								pids[PID_COORDINATED_FLIGHT_YAW].iAccumulator = 0;
								pids[PID_RATE_YAW].iAccumulator = 0;
								axis_lock_accum[YAW] = 0;
							}
							break;
						case ROLL:
						case PITCH:
						default:
							//Coordinated Flight has no effect in these modes. Trigger a configuration error.
							error = true;
							break;
					}

					break;

				case STABILIZATIONDESIRED_STABILIZATIONMODE_POI:
					// The sanity check enforces this is only selectable for Yaw
					// for a gimbal you can select pitch too.
					if(reinit) {
						pids[PID_GROUP_ATT + i].iAccumulator = 0;
						pids[PID_GROUP_RATE + i].iAccumulator = 0;
					}

					float error;
					float angle;
					if (CameraDesiredHandle()) {
						switch(i) {
						case PITCH:
							CameraDesiredDeclinationGet(&angle);
							error = circular_modulus_deg(angle - attitudeActual.Pitch);
							break;
						case ROLL:
						{
							uint8_t roll_fraction = 0;
#ifdef GIMBAL
							if (BrushlessGimbalSettingsHandle()) {
								BrushlessGimbalSettingsRollFractionGet(&roll_fraction);
							}
#endif /* GIMBAL */

							// For ROLL POI mode we track the FC roll angle (scaled) to
							// allow keeping some motion
							CameraDesiredRollGet(&angle);
							angle *= roll_fraction / 100.0f;
							error = circular_modulus_deg(angle - attitudeActual.Roll);
						}
							break;
						case YAW:
							CameraDesiredBearingGet(&angle);
							error = circular_modulus_deg(angle - attitudeActual.Yaw);
							break;
						default:
							error = true;
						}
					} else
						error = true;

					// Compute the outer loop
					rateDesiredAxis[i] = pid_apply(&pids[PID_GROUP_ATT + i], error, dT);
					rateDesiredAxis[i] = bound_sym(rateDesiredAxis[i], settings.PoiMaximumRate[i]);

					// Compute the inner loop
					actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_GROUP_RATE + i],  rateDesiredAxis[i],  gyro_filtered[i], dT);
					actuatorDesiredAxis[i] = bound_sym(actuatorDesiredAxis[i],1.0f);

					break;
				case STABILIZATIONDESIRED_STABILIZATIONMODE_NONE:
					actuatorDesiredAxis[i] = bound_sym(stabDesiredAxis[i],1.0f);
					break;
				default:
					error = true;
					break;
			}
		}

		if (settings.VbarPiroComp == STABILIZATIONSETTINGS_VBARPIROCOMP_TRUE)
			stabilization_virtual_flybar_pirocomp(gyro_filtered[2], dT);

#if defined(RATEDESIRED_DIAGNOSTICS)
		RateDesiredSet(&rateDesired);
#endif

		// Save dT
		actuatorDesired.UpdateTime = dT * 1000;
		actuatorDesired.Throttle = stabDesired.Throttle;

		if(flightStatus.FlightMode != FLIGHTSTATUS_FLIGHTMODE_MANUAL) {
			ActuatorDesiredSet(&actuatorDesired);
		} else {
			// Force all axes to reinitialize when engaged
			for(uint8_t i=0; i< MAX_AXES; i++)
				previous_mode[i] = 255;
		}

		if(flightStatus.Armed != FLIGHTSTATUS_ARMED_ARMED ||
		   (lowThrottleZeroIntegral && stabDesired.Throttle < 0))
		{
			// Force all axes to reinitialize when engaged
			for(uint8_t i=0; i< MAX_AXES; i++)
				previous_mode[i] = 255;
		}

		// Clear or set alarms.  Done like this to prevent toggling each cycle
		// and hammering system alarms
		if (error)
			AlarmsSet(SYSTEMALARMS_ALARM_STABILIZATION,SYSTEMALARMS_ALARM_ERROR);
		else
			AlarmsClear(SYSTEMALARMS_ALARM_STABILIZATION);
	}
}