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Stabilization: new stabilization variant based on les stabilization module, with several options for coordinate system transformation

git-svn-id: svn://svn.openpilot.org/OpenPilot/trunk@1990 ebee16cc-31ac-478f-84a7-5cbb03baadba
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corvus 2010-10-18 14:46:45 +00:00 committed by corvus
parent a0a296562f
commit 8cb04a372f
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/**
******************************************************************************
* @addtogroup OpenPilotModules OpenPilot Modules
* @{
* @addtogroup StabilizationModule Stabilization Module
* @brief Stabilization PID loops in an airframe type independent manner
* @note This object updates the @ref ActuatorDesired "Actuator Desired" based on the
* PID loops on the @ref AttitudeDesired "Attitude Desired" and @ref AttitudeActual "Attitude Actual"
* @{
*
* @file stabilization.h
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief Attitude stabilization module.
*
* @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
*/
#ifndef STABILIZATION_H
#define STABILIZATION_H
int32_t StabilizationInitialize();
#endif // STABILIZATION_H
/**
* @}
* @}
*/

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/**
******************************************************************************
* @addtogroup OpenPilotModules OpenPilot Modules
* @{
* @addtogroup StabilizationModule Stabilization Module
* @brief Stabilization PID loops in an airframe type independent manner
* @note This object updates the @ref ActuatorDesired "Actuator Desired" based on the
* PID loops on the @ref AttitudeDesired "Attitude Desired" and @ref AttitudeActual "Attitude Actual"
* @{
*
* @file stabilization.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief Attitude stabilization module.
*
* @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
*/
#include "openpilot.h"
#include "stabilization.h"
#include "stabilizationsettings.h"
#include "actuatordesired.h"
#include "attitudedesired.h"
#include "attitudeactual.h"
#include "attituderaw.h"
#include "manualcontrolcommand.h"
#include "systemsettings.h"
#include "ahrssettings.h"
// Private constants
#define MAX_QUEUE_SIZE 2
#define STACK_SIZE configMINIMAL_STACK_SIZE
#define TASK_PRIORITY (tskIDLE_PRIORITY+4)
#define FAILSAFE_TIMEOUT_MS 100
#define DEG2RAD ( M_PI / 180.0 )
// Stabilizisation variant
enum {TRANSLATE_NONE, TRANSLATE_ATTITUDE, TRANSLATE_RATES, TRANSLATE_ACTUATORS};
#define TRANSLATE_COORDS TRANSLATE_ATTITUDE
// TRANSLATE_NONE <-- no coordinate translation - old behaviour - no rotation
// TRANSLATE_ATTITUDE <-- suggestion by corvus - rotate attitude error into local reference frame
// TRANSLATE_RATES <-- rotate rate error into local reference frame
// TRANSLATE_ACTUATORS <-- rotate actuator demands into local reference frame
// WARNING: MANUALCONTROLCOMMAND_STABILIZATIONSETTINGS_RATE
// will behave differently depending on whether and when translation takes place
// "none" and "attitude" - rates will be stabilized in local reference frame
// "rates" and "actuators" - rates will be stabilized in global reference frame
enum {METHOD_ROLL, METHOD_FULL};
#define TRANSLATE_METHOD METHOD_ROLL
// WARNING: experimental feature "full" is untested!
enum {PID_RATE_ROLL, PID_RATE_PITCH, PID_RATE_YAW, PID_ROLL, PID_PITCH, PID_YAW, PID_MAX};
enum {ROLL,PITCH,YAW,MAX_AXES};
// Private types
typedef struct {
float p;
float i;
float d;
float iLim;
float iAccumulator;
float lastErr;
} pid_type;
// Private variables
static xTaskHandle taskHandle;
static StabilizationSettingsData settings;
static xQueueHandle queue;
float dT = 1;
pid_type pids[PID_MAX];
// Private functions
static void stabilizationTask(void* parameters);
static float ApplyPid(pid_type * pid, const float error);
static float bound(float val);
static void ZeroPids(void);
static void SettingsUpdatedCb(UAVObjEvent * ev);
static void calcDifference(float * values, float * reference, const uint8_t angular);
static void translateValues(float * values, float * reference);
/**
* Module initialization
*/
int32_t StabilizationInitialize()
{
// Initialize variables
// Create object queue
queue = xQueueCreate(MAX_QUEUE_SIZE, sizeof(UAVObjEvent));
// Listen for updates.
AttitudeActualConnectQueue(queue);
AttitudeRawConnectQueue(queue);
StabilizationSettingsConnectCallback(SettingsUpdatedCb);
SettingsUpdatedCb(StabilizationSettingsHandle());
// Start main task
xTaskCreate(stabilizationTask, (signed char*)"Stabilization", STACK_SIZE, NULL, TASK_PRIORITY, &taskHandle);
return 0;
}
/**
* Module task
*/
static void stabilizationTask(void* parameters)
{
portTickType lastSysTime;
portTickType thisSysTime;
UAVObjEvent ev;
ActuatorDesiredData actuatorDesired;
AttitudeDesiredData attitudeDesired;
AttitudeActualData attitudeActual;
AttitudeRawData attitudeRaw;
SystemSettingsData systemSettings;
ManualControlCommandData manualControl;
SettingsUpdatedCb((UAVObjEvent *) NULL);
// Main task loop
lastSysTime = xTaskGetTickCount();
ZeroPids();
while(1) {
// Wait until the ActuatorDesired 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);
}
// 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;
ManualControlCommandGet(&manualControl);
AttitudeDesiredGet(&attitudeDesired);
AttitudeActualGet(&attitudeActual);
AttitudeRawGet(&attitudeRaw);
SystemSettingsGet(&systemSettings);
float *manualAxis = &manualControl.Roll;
float *attitudeDesiredAxis = &attitudeDesired.Roll;
float *attitudeActualAxis = &attitudeActual.Roll;
float *actuatorDesiredAxis = &actuatorDesired.Roll;
// calculate attitude errors
calcDifference( attitudeDesiredAxis, attitudeActualAxis, 1);
#if TRANSLATE_COORDS == TRANSLATE_ATTITUDE
//Translate Attitude to local reference frame.
translateValues(attitudeDesiredAxis, attitudeActualAxis);
#endif
//Calculate desired rate
float rates[MAX_AXES]= {0,0,0};
for(int8_t ct=0; ct< MAX_AXES; ct++)
{
switch(manualControl.StabilizationSettings[ct])
{
case MANUALCONTROLCOMMAND_STABILIZATIONSETTINGS_RATE:
rates[ct] = manualAxis[ct] * settings.ManualRate[ct];
break;
case MANUALCONTROLCOMMAND_STABILIZATIONSETTINGS_ATTITUDE:
rates[ct] = ApplyPid(&pids[PID_ROLL + ct], attitudeDesiredAxis[ct]);
break;
}
if(fabs(rates[ct]) > settings.MaximumRate[ct])
{
if(rates[ct] > 0)
{
rates[ct] = settings.MaximumRate[ct];
}else
{
rates[ct] = -settings.MaximumRate[ct];
}
}
}
uint8_t shouldUpdate = 0;
ActuatorDesiredGet(&actuatorDesired);
// calculate rate errors
calcDifference( rates, attitudeRaw.gyros_filtered, 0);
#if TRANSLATE_COORDS == TRANSLATE_RATES
//Translate rate errors to local reference frame.
translateValues(rates, attitudeActualAxis);
#endif
//Calculate desired command
for(int8_t ct=0; ct< MAX_AXES; ct++)
{
switch(manualControl.StabilizationSettings[ct])
{
case MANUALCONTROLCOMMAND_STABILIZATIONSETTINGS_RATE:
case MANUALCONTROLCOMMAND_STABILIZATIONSETTINGS_ATTITUDE:
{
float command = ApplyPid(&pids[PID_RATE_ROLL + ct], rates[ct]);
actuatorDesiredAxis[ct] = bound(command);
shouldUpdate = 1;
break;
}
}
}
#if TRANSLATE_COORDS == TRANSLATE_ACTUATORS
//Translate Actuator settings to local reference frame.
translateValues(actuatorDesiredAxis,attitudeActualAxis);
#endif
// Save dT
actuatorDesired.UpdateTime = dT * 1000;
if(manualControl.FlightMode == MANUALCONTROLCOMMAND_FLIGHTMODE_MANUAL)
{
shouldUpdate = 0;
}
if(shouldUpdate)
{
actuatorDesired.Throttle = attitudeDesired.Throttle;
ActuatorDesiredSet(&actuatorDesired);
}
if(manualControl.Armed == MANUALCONTROLCOMMAND_ARMED_FALSE ||
!shouldUpdate || (attitudeDesired.Throttle < 0))
{
ZeroPids();
}
// Clear alarms
AlarmsClear(SYSTEMALARMS_ALARM_STABILIZATION);
}
}
float ApplyPid(pid_type * pid, const float err)
{
float diff = (err - pid->lastErr);
pid->lastErr = err;
pid->iAccumulator += err * pid->i * dT;
if(fabs(pid->iAccumulator) > pid->iLim) {
if(pid->iAccumulator >0) {
pid->iAccumulator = pid->iLim;
} else {
pid->iAccumulator = -pid->iLim;
}
}
return ((err * pid->p) + pid->iAccumulator + (diff * pid->d / dT));
}
static void ZeroPids(void)
{
for(int8_t ct = 0; ct < PID_MAX; ct++) {
pids[ct].iAccumulator = 0;
pids[ct].lastErr = 0;
}
}
/**
* Bound input value between limits
*/
static float bound(float val)
{
if(val < -1) {
val = -1;
} else if(val > 1) {
val = 1;
}
return val;
}
/**
* calculate difference vector
*/
static void calcDifference(float * values, float * reference, const uint8_t angular)
{
for(int8_t ct=0; ct< MAX_AXES; ct++)
{
values[ct] = values[ct] - reference[ct];
if (angular) {
if (values[ct] > 180.) values[ct] -= 360.;
if (values[ct] < -180.) values[ct] += 360.;
}
}
}
/**
* translate rotational vector into local reference frame
*/
static void translateValues(float * values, float * reference)
{
float tmp[MAX_AXES];
#if TRANSLATE_METHOD == METHOD_FULL && TRANSLATE_COORDS == TRANSLATE_ATTITUDE
// UNTESTED!!! (and also likely unnecessary since neglectible for small values)
// adjust PITCH to corect the (PITCH) difference between a YAW rotation around the
// vertical axis and a YAW rotation around the local vertical axis
// WARNING!!! This only makes sense if values[YAW] is an angle.
// Therefore it cannot work for rates and/or actuatorDemands
values[PITCH] = values[PITCH] + ( reference[PITCH] - cos( DEG2RAD * values[YAW] ) * reference[PITCH] );
#endif
// traditional translation: rotate YAW and PITCH by roll
tmp[PITCH] = cos( DEG2RAD * reference[ROLL] ) * values[PITCH]
+ sin( DEG2RAD * reference[ROLL] ) * values[YAW];
tmp[YAW] = cos( DEG2RAD * reference[ROLL] ) * values[YAW]
+ sin( DEG2RAD * reference[ROLL] ) * values[PITCH];
values[PITCH] = tmp[PITCH];
values[YAW] = tmp[YAW];
}
static void SettingsUpdatedCb(UAVObjEvent * ev)
{
memset(pids,0,sizeof (pid_type) * PID_MAX);
StabilizationSettingsGet(&settings);
float * data = settings.RollRatePI;
for(int8_t pid=0; pid < PID_MAX; pid++)
{
pids[pid].p = *data++;
pids[pid].i = *data++;
pids[pid].iLim = *data++;
}
}
/**
* @}
* @}
*/