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LibrePilot/flight/Modules/Attitude/attitude.c

632 lines
19 KiB
C

/**
******************************************************************************
* @addtogroup OpenPilotModules OpenPilot Modules
* @{
* @addtogroup Attitude Copter Control Attitude Estimation
* @brief Acquires sensor data and computes attitude estimate
* Specifically updates the the @ref AttitudeActual "AttitudeActual" and @ref AttitudeRaw "AttitudeRaw" settings objects
* @{
*
* @file attitude.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief Module to handle all comms to the AHRS on a periodic basis.
*
* @see The GNU Public License (GPL) Version 3
*
******************************************************************************/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* Input objects: None, takes sensor data via pios
* Output objects: @ref AttitudeRaw @ref AttitudeActual
*
* This module computes an attitude estimate from the sensor data
*
* The module executes in its own thread.
*
* UAVObjects are automatically generated by the UAVObjectGenerator from
* the object definition XML file.
*
* Modules have no API, all communication to other modules is done through UAVObjects.
* However modules may use the API exposed by shared libraries.
* See the OpenPilot wiki for more details.
* http://www.openpilot.org/OpenPilot_Application_Architecture
*
*/
#include "pios.h"
#include "attitude.h"
#include "gyros.h"
#include "accels.h"
#include "attitudeactual.h"
#include "attitudesettings.h"
#include "flightstatus.h"
#include "manualcontrolcommand.h"
#include "CoordinateConversions.h"
#include <pios_board_info.h>
// Private constants
#define STACK_SIZE_BYTES 540
#define TASK_PRIORITY (tskIDLE_PRIORITY+3)
#define SENSOR_PERIOD 4
#define UPDATE_RATE 25.0f
#define GYRO_NEUTRAL 1665
#define PI_MOD(x) (fmod(x + M_PI, M_PI * 2) - M_PI)
// Private types
// Private variables
static xTaskHandle taskHandle;
// Private functions
static void AttitudeTask(void *parameters);
static float gyro_correct_int[3] = {0,0,0};
static xQueueHandle gyro_queue;
static int32_t updateSensors(AccelsData *, GyrosData *);
static int32_t updateSensorsCC3D(AccelsData * accelsData, GyrosData * gyrosData);
static void updateAttitude(AccelsData *, GyrosData *);
static void settingsUpdatedCb(UAVObjEvent * objEv);
static float accelKi = 0;
static float accelKp = 0;
static float accel_alpha = 0;
static bool accel_filter_enabled = false;
static float accels_filtered[3];
static float grot_filtered[3];
static float yawBiasRate = 0;
static float gyroGain = 0.42;
static int16_t accelbias[3];
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;
// For running trim flights
static volatile bool trim_requested = false;
static volatile int32_t trim_accels[3];
static volatile int32_t trim_samples;
int32_t const MAX_TRIM_FLIGHT_SAMPLES = 65535;
#define GRAV 9.81f
#define ACCEL_SCALE (GRAV * 0.004f)
/* 0.004f is gravity / LSB */
/**
* Initialise the module, called on startup
* \returns 0 on success or -1 if initialisation failed
*/
int32_t AttitudeStart(void)
{
// Start main task
xTaskCreate(AttitudeTask, (signed char *)"Attitude", STACK_SIZE_BYTES/4, NULL, TASK_PRIORITY, &taskHandle);
TaskMonitorAdd(TASKINFO_RUNNING_ATTITUDE, taskHandle);
PIOS_WDG_RegisterFlag(PIOS_WDG_ATTITUDE);
return 0;
}
/**
* Initialise the module, called on startup
* \returns 0 on success or -1 if initialisation failed
*/
int32_t AttitudeInitialize(void)
{
AttitudeActualInitialize();
AttitudeSettingsInitialize();
AccelsInitialize();
GyrosInitialize();
// Initialize quaternion
AttitudeActualData attitude;
AttitudeActualGet(&attitude);
attitude.q1 = 1;
attitude.q2 = 0;
attitude.q3 = 0;
attitude.q4 = 0;
AttitudeActualSet(&attitude);
// Cannot trust the values to init right above if BL runs
gyro_correct_int[0] = 0;
gyro_correct_int[1] = 0;
gyro_correct_int[2] = 0;
q[0] = 1;
q[1] = 0;
q[2] = 0;
q[3] = 0;
for(uint8_t i = 0; i < 3; i++)
for(uint8_t j = 0; j < 3; j++)
R[i][j] = 0;
trim_requested = false;
AttitudeSettingsConnectCallback(&settingsUpdatedCb);
return 0;
}
MODULE_INITCALL(AttitudeInitialize, AttitudeStart)
/**
* Module thread, should not return.
*/
int32_t accel_test;
int32_t gyro_test;
static void AttitudeTask(void *parameters)
{
uint8_t init = 0;
AlarmsClear(SYSTEMALARMS_ALARM_ATTITUDE);
// Set critical error and wait until the accel is producing data
while(PIOS_ADXL345_FifoElements() == 0) {
AlarmsSet(SYSTEMALARMS_ALARM_ATTITUDE, SYSTEMALARMS_ALARM_CRITICAL);
PIOS_WDG_UpdateFlag(PIOS_WDG_ATTITUDE);
}
const struct pios_board_info * bdinfo = &pios_board_info_blob;
bool cc3d = bdinfo->board_rev == 0x02;
if(cc3d) {
#if defined(PIOS_INCLUDE_MPU6000)
gyro_test = PIOS_MPU6000_Test();
#endif
} else {
#if defined(PIOS_INCLUDE_ADXL345)
accel_test = PIOS_ADXL345_Test();
#endif
#if defined(PIOS_INCLUDE_ADC)
// Create queue for passing gyro data, allow 2 back samples in case
gyro_queue = xQueueCreate(1, sizeof(float) * 4);
PIOS_Assert(gyro_queue != NULL);
PIOS_ADC_SetQueue(gyro_queue);
PIOS_ADC_Config((PIOS_ADC_RATE / 1000.0f) * UPDATE_RATE);
#endif
}
// Force settings update to make sure rotation loaded
settingsUpdatedCb(AttitudeSettingsHandle());
// Main task loop
while (1) {
FlightStatusData flightStatus;
FlightStatusGet(&flightStatus);
if((xTaskGetTickCount() < 7000) && (xTaskGetTickCount() > 1000)) {
// For first 7 seconds use accels to get gyro bias
accelKp = 1;
accelKi = 0.9;
yawBiasRate = 0.23;
accel_filter_enabled = false;
init = 0;
}
else if (zero_during_arming && (flightStatus.Armed == FLIGHTSTATUS_ARMED_ARMING)) {
accelKp = 1;
accelKi = 0.9;
yawBiasRate = 0.23;
accel_filter_enabled = false;
init = 0;
} else if (init == 0) {
// Reload settings (all the rates)
AttitudeSettingsAccelKiGet(&accelKi);
AttitudeSettingsAccelKpGet(&accelKp);
AttitudeSettingsYawBiasRateGet(&yawBiasRate);
if (accel_alpha > 0.0f)
accel_filter_enabled = true;
init = 1;
}
PIOS_WDG_UpdateFlag(PIOS_WDG_ATTITUDE);
AccelsData accels;
GyrosData gyros;
int32_t retval = 0;
if (cc3d)
retval = updateSensorsCC3D(&accels, &gyros);
else
retval = updateSensors(&accels, &gyros);
// Only update attitude when sensor data is good
if (retval != 0)
AlarmsSet(SYSTEMALARMS_ALARM_ATTITUDE, SYSTEMALARMS_ALARM_ERROR);
else {
// Do not update attitude data in simulation mode
if (!AttitudeActualReadOnly())
updateAttitude(&accels, &gyros);
AlarmsClear(SYSTEMALARMS_ALARM_ATTITUDE);
}
}
}
float gyros_passed[3];
/**
* Get an update from the sensors
* @param[in] attitudeRaw Populate the UAVO instead of saving right here
* @return 0 if successfull, -1 if not
*/
static int32_t updateSensors(AccelsData * accels, GyrosData * gyros)
{
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 -1;
}
// Do not read raw sensor data in simulation mode
if (GyrosReadOnly() || AccelsReadOnly())
return 0;
// No accel data available
if(PIOS_ADXL345_FifoElements() == 0)
return -1;
// First sample is temperature
gyros->x = -(gyro[1] - GYRO_NEUTRAL) * gyroGain;
gyros->y = (gyro[2] - GYRO_NEUTRAL) * gyroGain;
gyros->z = -(gyro[3] - GYRO_NEUTRAL) * gyroGain;
int32_t x = 0;
int32_t y = 0;
int32_t z = 0;
uint8_t i = 0;
uint8_t samples_remaining;
do {
i++;
samples_remaining = PIOS_ADXL345_Read(&accel_data);
x += accel_data.x;
y += -accel_data.y;
z += -accel_data.z;
} while ( (i < 32) && (samples_remaining > 0) );
gyros->temperature = samples_remaining;
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];
rot_mult(R, accel, vec_out);
accels->x = vec_out[0];
accels->y = vec_out[1];
accels->z = vec_out[2];
rot_mult(R, &gyros->x, vec_out);
gyros->x = vec_out[0];
gyros->y = vec_out[1];
gyros->z = vec_out[2];
} else {
accels->x = accel[0];
accels->y = accel[1];
accels->z = accel[2];
}
if (trim_requested) {
if (trim_samples >= MAX_TRIM_FLIGHT_SAMPLES) {
trim_requested = false;
} else {
uint8_t armed;
float throttle;
FlightStatusArmedGet(&armed);
ManualControlCommandThrottleGet(&throttle); // Until flight status indicates airborne
if ((armed == FLIGHTSTATUS_ARMED_ARMED) && (throttle > 0)) {
trim_samples++;
// Store the digitally scaled version since that is what we use for bias
trim_accels[0] += accels->x;
trim_accels[1] += accels->y;
trim_accels[2] += accels->z;
}
}
}
// Scale accels and correct bias
accels->x = (accels->x - accelbias[0]) * ACCEL_SCALE;
accels->y = (accels->y - accelbias[1]) * ACCEL_SCALE;
accels->z = (accels->z - accelbias[2]) * ACCEL_SCALE;
if(bias_correct_gyro) {
// Applying integral component here so it can be seen on the gyros and correct bias
gyros->x += gyro_correct_int[0];
gyros->y += gyro_correct_int[1];
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] += - gyros->z * yawBiasRate;
GyrosSet(gyros);
AccelsSet(accels);
return 0;
}
/**
* Get an update from the sensors
* @param[in] attitudeRaw Populate the UAVO instead of saving right here
* @return 0 if successfull, -1 if not
*/
struct pios_mpu6000_data mpu6000_data;
static int32_t updateSensorsCC3D(AccelsData * accelsData, GyrosData * gyrosData)
{
float accels[3], gyros[3];
#if defined(PIOS_INCLUDE_MPU6000)
xQueueHandle queue = PIOS_MPU6000_GetQueue();
if(xQueueReceive(queue, (void *) &mpu6000_data, SENSOR_PERIOD) == errQUEUE_EMPTY)
return -1; // Error, no data
// Do not read raw sensor data in simulation mode
if (GyrosReadOnly() || AccelsReadOnly())
return 0;
gyros[0] = -mpu6000_data.gyro_y * PIOS_MPU6000_GetScale();
gyros[1] = -mpu6000_data.gyro_x * PIOS_MPU6000_GetScale();
gyros[2] = -mpu6000_data.gyro_z * PIOS_MPU6000_GetScale();
accels[0] = -mpu6000_data.accel_y * PIOS_MPU6000_GetAccelScale();
accels[1] = -mpu6000_data.accel_x * PIOS_MPU6000_GetAccelScale();
accels[2] = -mpu6000_data.accel_z * PIOS_MPU6000_GetAccelScale();
gyrosData->temperature = 35.0f + ((float) mpu6000_data.temperature + 512.0f) / 340.0f;
accelsData->temperature = 35.0f + ((float) mpu6000_data.temperature + 512.0f) / 340.0f;
#endif
if(rotate) {
// TODO: rotate sensors too so stabilization is well behaved
float vec_out[3];
rot_mult(R, accels, vec_out);
accels[0] = vec_out[0];
accels[1] = vec_out[1];
accels[2] = vec_out[2];
rot_mult(R, gyros, vec_out);
gyros[0] = vec_out[0];
gyros[1] = vec_out[1];
gyros[2] = vec_out[2];
}
accelsData->x = accels[0] - accelbias[0] * ACCEL_SCALE; // Applying arbitrary scale here to match CC v1
accelsData->y = accels[1] - accelbias[1] * ACCEL_SCALE;
accelsData->z = accels[2] - accelbias[2] * ACCEL_SCALE;
gyrosData->x = gyros[0];
gyrosData->y = gyros[1];
gyrosData->z = gyros[2];
if(bias_correct_gyro) {
// Applying integral component here so it can be seen on the gyros and correct bias
gyrosData->x += gyro_correct_int[0];
gyrosData->y += gyro_correct_int[1];
gyrosData->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] += - gyrosData->z * yawBiasRate;
GyrosSet(gyrosData);
AccelsSet(accelsData);
return 0;
}
static inline void apply_accel_filter(const float *raw, float *filtered)
{
if (accel_filter_enabled) {
filtered[0] = filtered[0] * accel_alpha + raw[0] * (1 - accel_alpha);
filtered[1] = filtered[1] * accel_alpha + raw[1] * (1 - accel_alpha);
filtered[2] = filtered[2] * accel_alpha + raw[2] * (1 - accel_alpha);
} else {
filtered[0] = raw[0];
filtered[1] = raw[1];
filtered[2] = raw[2];
}
}
static void updateAttitude(AccelsData * accelsData, GyrosData * gyrosData)
{
float dT;
portTickType thisSysTime = xTaskGetTickCount();
static portTickType lastSysTime = 0;
dT = (thisSysTime == lastSysTime) ? 0.001 : (portMAX_DELAY & (thisSysTime - lastSysTime)) / portTICK_RATE_MS / 1000.0f;
lastSysTime = thisSysTime;
// Bad practice to assume structure order, but saves memory
float * gyros = &gyrosData->x;
float * accels = &accelsData->x;
float grot[3];
float accel_err[3];
// Apply smoothing to accel values, to reduce vibration noise before main calculations.
apply_accel_filter(accels, accels_filtered);
// Rotate gravity unit vector to body frame, filter 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]);
apply_accel_filter(grot, grot_filtered);
CrossProduct((const float *)accels_filtered, (const float *)grot_filtered, accel_err);
// Account for accel magnitude
float accel_mag = sqrtf(accels_filtered[0]*accels_filtered[0] + accels_filtered[1]*accels_filtered[1] + accels_filtered[2]*accels_filtered[2]);
if (accel_mag < 1.0e-3f)
return;
// Account for filtered gravity vector magnitude
float grot_mag;
if (accel_filter_enabled)
grot_mag = sqrtf(grot_filtered[0]*grot_filtered[0] + grot_filtered[1]*grot_filtered[1] + grot_filtered[2]*grot_filtered[2]);
else
grot_mag = 1.0f;
if (grot_mag < 1.0e-3f)
return;
accel_err[0] /= (accel_mag*grot_mag);
accel_err[1] /= (accel_mag*grot_mag);
accel_err[2] /= (accel_mag*grot_mag);
// Accumulate integral of error. Scale here so that units are (deg/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] * accelKi;
// Correct rates based on error, integral component dealt with in updateSensors
gyros[0] += accel_err[0] * accelKp / dT;
gyros[1] += accel_err[1] * accelKp / dT;
gyros[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
float qdot[4];
qdot[0] = (-q[1] * gyros[0] - q[2] * gyros[1] - q[3] * gyros[2]) * dT * M_PI / 180 / 2;
qdot[1] = (q[0] * gyros[0] - q[3] * gyros[1] + q[2] * gyros[2]) * dT * M_PI / 180 / 2;
qdot[2] = (q[3] * gyros[0] + q[0] * gyros[1] - q[1] * gyros[2]) * dT * M_PI / 180 / 2;
qdot[3] = (-q[2] * gyros[0] + q[1] * gyros[1] + q[0] * gyros[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];
if(q[0] < 0) {
q[0] = -q[0];
q[1] = -q[1];
q[2] = -q[2];
q[3] = -q[3];
}
}
// Renomalize
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 quaternion has become inappropriately short or is nan reinit.
// THIS SHOULD NEVER ACTUALLY HAPPEN
if((fabs(qmag) < 1e-3) || (qmag != qmag)) {
q[0] = 1;
q[1] = 0;
q[2] = 0;
q[3] = 0;
}
AttitudeActualData attitudeActual;
AttitudeActualGet(&attitudeActual);
quat_copy(q, &attitudeActual.q1);
// Convert into eueler degrees (makes assumptions about RPY order)
Quaternion2RPY(&attitudeActual.q1,&attitudeActual.Roll);
AttitudeActualSet(&attitudeActual);
}
static void settingsUpdatedCb(UAVObjEvent * objEv) {
AttitudeSettingsData attitudeSettings;
AttitudeSettingsGet(&attitudeSettings);
accelKp = attitudeSettings.AccelKp;
accelKi = attitudeSettings.AccelKi;
yawBiasRate = attitudeSettings.YawBiasRate;
gyroGain = attitudeSettings.GyroGain;
// Calculate accel filter alpha, in the same way as for gyro data in stabilization module.
const float fakeDt = 0.0025;
if (attitudeSettings.AccelTau < 0.0001) {
accel_alpha = 0; // not trusting this to resolve to 0
accel_filter_enabled = false;
} else {
accel_alpha = expf(-fakeDt / attitudeSettings.AccelTau);
accel_filter_enabled = true;
}
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] / 100.0f;
gyro_correct_int[1] = attitudeSettings.GyroBias[ATTITUDESETTINGS_GYROBIAS_Y] / 100.0f;
gyro_correct_int[2] = attitudeSettings.GyroBias[ATTITUDESETTINGS_GYROBIAS_Z] / 100.0f;
// 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],
attitudeSettings.BoardRotation[ATTITUDESETTINGS_BOARDROTATION_YAW]};
RPY2Quaternion(rpy, rotationQuat);
Quaternion2R(rotationQuat, R);
rotate = 1;
}
if (attitudeSettings.TrimFlight == ATTITUDESETTINGS_TRIMFLIGHT_START) {
trim_accels[0] = 0;
trim_accels[1] = 0;
trim_accels[2] = 0;
trim_samples = 0;
trim_requested = true;
} else if (attitudeSettings.TrimFlight == ATTITUDESETTINGS_TRIMFLIGHT_LOAD) {
trim_requested = false;
attitudeSettings.AccelBias[ATTITUDESETTINGS_ACCELBIAS_X] = trim_accels[0] / trim_samples;
attitudeSettings.AccelBias[ATTITUDESETTINGS_ACCELBIAS_Y] = trim_accels[1] / trim_samples;
// Z should average -grav
attitudeSettings.AccelBias[ATTITUDESETTINGS_ACCELBIAS_Z] = trim_accels[2] / trim_samples + GRAV / ACCEL_SCALE;
attitudeSettings.TrimFlight = ATTITUDESETTINGS_TRIMFLIGHT_NORMAL;
AttitudeSettingsSet(&attitudeSettings);
} else
trim_requested = false;
}
/**
* @}
* @}
*/