/* apply_quat:
* Multiplies the point (x, y, z) by the quaternion q, storing the result in
* (*xout, *yout, *zout). This is quite a bit slower than apply_matrix_f.
* So, only use it if you only need to translate a handful of points.
* Otherwise it is much more efficient to call quat_to_matrix then use
* apply_matrix_f.
*/
void apply_quat(AL_CONST QUAT *q, float x, float y, float z, float *xout, float *yout, float *zout)
{
QUAT v;
QUAT i;
QUAT t;
ASSERT(q);
ASSERT(xout);
ASSERT(yout);
ASSERT(zout);
/* v' = q * v * q^-1 */
v.w = 0;
v.x = x;
v.y = y;
v.z = z;
/* NOTE: Rotating about a zero quaternion is undefined. This can be shown
* by the fact that the inverse of a zero quaternion is undefined
* and therefore causes an exception below.
*/
ASSERT(!((q->x == 0.0) && (q->y == 0.0) && (q->z == 0.0) && (q->w == 0.0)));
quat_inverse(q, &i);
quat_mul(&i, &v, &t);
quat_mul(&t, q, &v);
*xout = v.x;
*yout = v.y;
*zout = v.z;
}
void quat_decompose_swing_twist(const union quat *q, const union vec3 *v1, union quat *swing, union quat *twist)
{
union vec3 v2;
quat_rot_vec(&v2, v1, q);
quat_from_u2v(swing, v1, &v2, 0);
union quat swing_inverse;
quat_inverse(&swing_inverse, swing);
quat_mul(twist, &swing_inverse, q);
}
union quat *quat_conjugate(union quat *qo, union quat *rotation, union quat *new_coord_system)
{
union quat temp, inverse;
/* Convert rotation to new coordinate system */
quat_mul(&temp, new_coord_system, rotation);
quat_inverse(&inverse, new_coord_system);
quat_mul(qo, &temp, &inverse);
return qo;
}
void quat_vector3_rotate (geometry_msgs::Quaternion q, geometry_msgs::Vector3 v, geometry_msgs::Vector3 *res)
{
geometry_msgs::Quaternion vq, q_inv, qa, qb;
vq.w = 0.0; vq.x = v.x; vq.y = v.y; vq.z = v.z;
quat_inverse (q, & q_inv);
quat_product (q, vq, & qa);
quat_product (qa, q_inv, & qb);
res -> x = qb.x;
res -> y = qb.y;
res -> z = qb.z;
}
void quat_logdif(AD_Quaternion *q1, AD_Quaternion *q2, AD_Quaternion *q3)
{
AD_Quaternion inv, dif;
float len, len1, s;
quat_inverse (q1, &inv);
quat_mul (&inv, q2, &dif);
len = sqrtf (dif.x*dif.x + dif.y*dif.y + dif.z*dif.z);
s = quat_dot (q1, q2);
if (s != 0.0) len1 = atanf (len / s); else len1 = (float)(M_PI/2.0f);
if (len != 0.0) len1 /= len;
q3->w = 0.0;
q3->x = dif.x * len1;
q3->y = dif.y * len1;
q3->z = dif.z * len1;
}
/**
* 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);
}
}
