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Code Issues Releases Activity

Added a field for initial gyro bias to speed up initialization.

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This commit is contained in:
James Cotton 2011-06-23 09:35:55 -05:00
parent 28501842c3
commit 0a4bbcc12e
2 changed files with 71 additions and 60 deletions
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129
flight/Modules/Attitude/attitude.c
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@ -3,7 +3,7 @@
* @addtogroup OpenPilotModules OpenPilot Modules
* @{
* @addtogroup Attitude Copter Control Attitude Estimation
* @brief Acquires sensor data and computes attitude estimate
* @brief Acquires sensor data and computes attitude estimate
* Specifically updates the the @ref AttitudeActual "AttitudeActual" and @ref AttitudeRaw "AttitudeRaw" settings objects
* @{
*
@ -89,6 +89,7 @@ static float q[4] = {1,0,0,0};
static float R[3][3];
static int8_t rotate = 0;
static bool zero_during_arming = false;
static bool bias_correct_gyro = true;
/**
* Initialise the module, called on startup
@ -104,15 +105,15 @@ int32_t AttitudeInitialize(void)
attitude.q3 = 0;
attitude.q4 = 0;
AttitudeActualSet(&attitude);
// Create queue for passing gyro data, allow 2 back samples in case
gyro_queue = xQueueCreate(1, sizeof(float) * 4);
if(gyro_queue == NULL)
if(gyro_queue == NULL)
return -1;
PIOS_ADC_SetQueue(gyro_queue);
AttitudeSettingsConnectCallback(&settingsUpdatedCb);
// Start main task
xTaskCreate(AttitudeTask, (signed char *)"Attitude", STACK_SIZE_BYTES/4, NULL, TASK_PRIORITY, &taskHandle);
TaskMonitorAdd(TASKINFO_RUNNING_ATTITUDE, taskHandle);
@ -132,13 +133,13 @@ static void AttitudeTask(void *parameters)
PIOS_ADC_Config((PIOS_ADC_RATE / 1000.0f) * UPDATE_RATE);
// Keep flash CS pin high while talking accel
PIOS_FLASH_DISABLE;
PIOS_FLASH_DISABLE;
PIOS_ADXL345_Init();
zero_during_arming = false;
// Main task loop
while (1) {
FlightStatusData flightStatus;
FlightStatusGet(&flightStatus);
@ -150,45 +151,45 @@ static void AttitudeTask(void *parameters)
accelKi = 0.9;
yawBiasRate = 0.23;
init = 0;
}
}
else if (zero_during_arming && (flightStatus.Armed == FLIGHTSTATUS_ARMED_ARMING)) {
accelKp = 1;
accelKi = 0.9;
yawBiasRate = 0.23;
init = 0;
init = 0;
} else if (init == 0) {
settingsUpdatedCb(AttitudeSettingsHandle());
init = 1;
}
}
PIOS_WDG_UpdateFlag(PIOS_WDG_ATTITUDE);
AttitudeRawData attitudeRaw;
AttitudeRawGet(&attitudeRaw);
updateSensors(&attitudeRaw);
AttitudeRawGet(&attitudeRaw);
updateSensors(&attitudeRaw);
updateAttitude(&attitudeRaw);
AttitudeRawSet(&attitudeRaw);
AttitudeRawSet(&attitudeRaw);
}
}
static void updateSensors(AttitudeRawData * attitudeRaw)
{
static void updateSensors(AttitudeRawData * attitudeRaw)
{
struct pios_adxl345_data accel_data;
float gyro[4];
// Only wait the time for two nominal updates before setting an alarm
if(xQueueReceive(gyro_queue, (void * const) gyro, UPDATE_RATE * 2) == errQUEUE_EMPTY) {
AlarmsSet(SYSTEMALARMS_ALARM_ATTITUDE, SYSTEMALARMS_ALARM_ERROR);
return;
}
// First sample is temperature
attitudeRaw->gyros[ATTITUDERAW_GYROS_X] = -(gyro[1] - GYRO_NEUTRAL) * gyroGain;
attitudeRaw->gyros[ATTITUDERAW_GYROS_Y] = (gyro[2] - GYRO_NEUTRAL) * gyroGain;
attitudeRaw->gyros[ATTITUDERAW_GYROS_Z] = -(gyro[3] - GYRO_NEUTRAL) * gyroGain;
int32_t x = 0;
int32_t y = 0;
int32_t z = 0;
@ -203,9 +204,9 @@ static void updateSensors(AttitudeRawData * attitudeRaw)
} while ( (i < 32) && (samples_remaining > 0) );
attitudeRaw->gyrotemp[0] = samples_remaining;
attitudeRaw->gyrotemp[1] = i;
float accel[3] = {(float) x / i, (float) y / i, (float) z / i};
if(rotate) {
// TODO: rotate sensors too so stabilization is well behaved
float vec_out[3];
@ -221,68 +222,71 @@ static void updateSensors(AttitudeRawData * attitudeRaw)
attitudeRaw->accels[0] = accel[0];
attitudeRaw->accels[1] = accel[1];
attitudeRaw->accels[2] = accel[2];
}
}
// Scale accels and correct bias
attitudeRaw->accels[ATTITUDERAW_ACCELS_X] = (attitudeRaw->accels[ATTITUDERAW_ACCELS_X] - accelbias[0]) * 0.004f * 9.81f;
attitudeRaw->accels[ATTITUDERAW_ACCELS_Y] = (attitudeRaw->accels[ATTITUDERAW_ACCELS_Y] - accelbias[1]) * 0.004f * 9.81f;
attitudeRaw->accels[ATTITUDERAW_ACCELS_Z] = (attitudeRaw->accels[ATTITUDERAW_ACCELS_Z] - accelbias[2]) * 0.004f * 9.81f;
// Applying integral component here so it can be seen on the gyros and correct bias
attitudeRaw->gyros[ATTITUDERAW_GYROS_X] += gyro_correct_int[0];
attitudeRaw->gyros[ATTITUDERAW_GYROS_Y] += gyro_correct_int[1];
// Because most crafts wont get enough information from gravity to zero yaw gyro
attitudeRaw->gyros[ATTITUDERAW_GYROS_Z] += gyro_correct_int[2];
gyro_correct_int[2] += - attitudeRaw->gyros[ATTITUDERAW_GYROS_Z] * yawBiasRate;
if(bias_correct_gyro) {
// Applying integral component here so it can be seen on the gyros and correct bias
attitudeRaw->gyros[ATTITUDERAW_GYROS_X] += gyro_correct_int[0];
attitudeRaw->gyros[ATTITUDERAW_GYROS_Y] += gyro_correct_int[1];
attitudeRaw->gyros[ATTITUDERAW_GYROS_Z] += gyro_correct_int[2];
}
// Because most crafts wont get enough information from gravity to zero yaw gyro, we try
// and make it average zero (weakly)
gyro_correct_int[2] += - attitudeRaw->gyros[ATTITUDERAW_GYROS_Z] * yawBiasRate;
}
static void updateAttitude(AttitudeRawData * attitudeRaw)
{
static portTickType lastSysTime = 0;
static portTickType thisSysTime;
static float dT = 0;
thisSysTime = xTaskGetTickCount();
if(thisSysTime > lastSysTime) // reuse dt in case of wraparound
dT = (thisSysTime - lastSysTime) / portTICK_RATE_MS / 1000.0f;
lastSysTime = thisSysTime;
// Bad practice to assume structure order, but saves memory
float gyro[3];
gyro[0] = attitudeRaw->gyros[0];
gyro[1] = attitudeRaw->gyros[1];
gyro[2] = attitudeRaw->gyros[2];
{
float * accels = attitudeRaw->accels;
float grot[3];
float accel_err[3];
// Rotate gravity to body frame and cross with accels
grot[0] = -(2 * (q[1] * q[3] - q[0] * q[2]));
grot[1] = -(2 * (q[2] * q[3] + q[0] * q[1]));
grot[2] = -(q[0] * q[0] - q[1]*q[1] - q[2]*q[2] + q[3]*q[3]);
CrossProduct((const float *) accels, (const float *) grot, accel_err);
// Account for accel magnitude
// Account for accel magnitude
float accel_mag = sqrt(accels[0]*accels[0] + accels[1]*accels[1] + accels[2]*accels[2]);
accel_err[0] /= accel_mag;
accel_err[1] /= accel_mag;
accel_err[2] /= accel_mag;
// Accumulate integral of error. Scale here so that units are (rad/s) but Ki has units of s
gyro_correct_int[0] += accel_err[0] * accelKi;
gyro_correct_int[1] += accel_err[1] * accelKi;
//gyro_correct_int[2] += accel_err[2] * settings.AccelKI * dT;
// Correct rates based on error, integral component dealt with in updateSensors
gyro[0] += accel_err[0] * accelKp / dT;
gyro[1] += accel_err[1] * accelKp / dT;
gyro[2] += accel_err[2] * accelKp / dT;
}
{ // scoping variables to save memory
// Work out time derivative from INSAlgo writeup
// Also accounts for the fact that gyros are in deg/s
@ -291,28 +295,28 @@ static void updateAttitude(AttitudeRawData * attitudeRaw)
qdot[1] = (q[0] * gyro[0] - q[3] * gyro[1] + q[2] * gyro[2]) * dT * M_PI / 180 / 2;
qdot[2] = (q[3] * gyro[0] + q[0] * gyro[1] - q[1] * gyro[2]) * dT * M_PI / 180 / 2;
qdot[3] = (-q[2] * gyro[0] + q[1] * gyro[1] + q[0] * gyro[2]) * dT * M_PI / 180 / 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];
}
// Renomalize
float qmag = sqrt(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;
AttitudeActualData attitudeActual;
AttitudeActualGet(&attitudeActual);
quat_copy(q, &attitudeActual.q1);
// Convert into eueler degrees (makes assumptions about RPY order)
Quaternion2RPY(&attitudeActual.q1,&attitudeActual.Roll);
Quaternion2RPY(&attitudeActual.q1,&attitudeActual.Roll);
AttitudeActualSet(&attitudeActual);
}
@ -320,36 +324,41 @@ static void updateAttitude(AttitudeRawData * attitudeRaw)
static void settingsUpdatedCb(UAVObjEvent * objEv) {
AttitudeSettingsData attitudeSettings;
AttitudeSettingsGet(&attitudeSettings);
accelKp = attitudeSettings.AccelKp;
accelKi = attitudeSettings.AccelKi;
accelKi = attitudeSettings.AccelKi;
yawBiasRate = attitudeSettings.YawBiasRate;
gyroGain = attitudeSettings.GyroGain;
zero_during_arming = attitudeSettings.ZeroDuringArming == ATTITUDESETTINGS_ZERODURINGARMING_TRUE;
bias_correct_gyro = attitudeSettings.BiasCorrectGyro == ATTITUDESETTINGS_BIASCORRECTGYRO_TRUE;
accelbias[0] = attitudeSettings.AccelBias[ATTITUDESETTINGS_ACCELBIAS_X];
accelbias[1] = attitudeSettings.AccelBias[ATTITUDESETTINGS_ACCELBIAS_Y];
accelbias[2] = attitudeSettings.AccelBias[ATTITUDESETTINGS_ACCELBIAS_Z];
gyro_correct_int[0] = attitudeSettings.GyroBias[ATTITUDESETTINGS_GYROBIAS_X];
gyro_correct_int[1] = attitudeSettings.GyroBias[ATTITUDESETTINGS_GYROBIAS_Y];
gyro_correct_int[2] = attitudeSettings.GyroBias[ATTITUDESETTINGS_GYROBIAS_Z];
// Indicates not to expend cycles on rotation
if(attitudeSettings.BoardRotation[0] == 0 && attitudeSettings.BoardRotation[1] == 0 &&
attitudeSettings.BoardRotation[2] == 0) {
rotate = 0;
// Shouldn't be used but to be safe
float rotationQuat[4] = {1,0,0,0};
Quaternion2R(rotationQuat, R);
} else {
float rotationQuat[4];
const float rpy[3] = {attitudeSettings.BoardRotation[ATTITUDESETTINGS_BOARDROTATION_ROLL],
attitudeSettings.BoardRotation[ATTITUDESETTINGS_BOARDROTATION_PITCH],
const float rpy[3] = {attitudeSettings.BoardRotation[ATTITUDESETTINGS_BOARDROTATION_ROLL],
attitudeSettings.BoardRotation[ATTITUDESETTINGS_BOARDROTATION_PITCH],
attitudeSettings.BoardRotation[ATTITUDESETTINGS_BOARDROTATION_YAW]};
RPY2Quaternion(rpy, rotationQuat);
Quaternion2R(rotationQuat, R);
rotate = 1;
}
}
}
/**
* @}

2
shared/uavobjectdefinition/attitudesettings.xml
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@ -2,12 +2,14 @@
<object name="AttitudeSettings" singleinstance="true" settings="true">
<description>Settings for the @ref Attitude module used on CopterControl</description>
<field name="AccelBias" units="lsb" type="int16" elementnames="X,Y,Z" defaultvalue="0"/>
<field name="GyroBias" units="deg/s" type="int8" elementnames="X,Y,Z" defaultvalue="0"/>
<field name="BoardRotation" units="deg" type="int16" elementnames="Roll,Pitch,Yaw" defaultvalue="0,0,0"/>
<field name="GyroGain" units="(rad/s)/lsb" type="float" elements="1" defaultvalue="0.42"/>
<field name="AccelKp" units="channel" type="float" elements="1" defaultvalue="0.03"/>
<field name="AccelKi" units="channel" type="float" elements="1" defaultvalue="0.0001"/>
<field name="YawBiasRate" units="channel" type="float" elements="1" defaultvalue="0.000001"/>
<field name="ZeroDuringArming" units="channel" type="enum" elements="1" options="FALSE,TRUE" defaultvalue="FALSE"/>
<field name="BiasCorrectGyro" units="channel" type="enum" elements="1" options="FALSE,TRUE" defaultvalue="TRUE"/>
<access gcs="readwrite" flight="readwrite"/>
<telemetrygcs acked="true" updatemode="onchange" period="0"/>
<telemetryflight acked="true" updatemode="onchange" period="0"/>