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Create a sine lookup table that is cached in flash and make relay tuning start

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ot use this.
This commit is contained in:
James Cotton 2012-08-02 01:53:55 -05:00
parent 924c91ce1e
commit aae0e562c6
6 changed files with 143 additions and 45 deletions
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2
flight/CopterControl/Makefile
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@ -268,6 +268,7 @@ SRC += $(PIOSCOMMON)/printf-stdarg.c
## Libraries for flight calculations
SRC += $(FLIGHTLIB)/fifo_buffer.c
SRC += $(FLIGHTLIB)/CoordinateConversions.c
SRC += $(FLIGHTLIB)/math/sin_lookup.c
SRC += $(FLIGHTLIB)/taskmonitor.c
## CMSIS for STM32
@ -369,6 +370,7 @@ EXTRAINCDIRS += $(OPUAVSYNTHDIR)
EXTRAINCDIRS += $(PIOS)
EXTRAINCDIRS += $(PIOSINC)
EXTRAINCDIRS += $(FLIGHTLIBINC)
EXTRAINCDIRS += $(FLIGHTLIB)/math
EXTRAINCDIRS += $(PIOSSTM32F10X)
EXTRAINCDIRS += $(PIOSCOMMON)
EXTRAINCDIRS += $(PIOSBOARDS)

99
flight/Libraries/math/sin_lookup.c Normal file
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@ -0,0 +1,99 @@
/**
******************************************************************************
* @addtogroup OpenPilot Math Utilities
* @{
* @addtogroup Sine and cosine methods that use a cached lookup table
* @{
*
* @file sin_lookup.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
* @brief Sine lookup table from flash with 1 degree resolution
*
* @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 "math.h"
#include "stdint.h"
// This is a precomputed sin lookup table over 90 degrees that
const float sin_table[] = {
0.000000f,0.017452f,0.034899f,0.052336f,0.069756f,0.087156f,0.104528f,0.121869f,0.139173f,0.156434f,
0.173648f,0.190809f,0.207912f,0.224951f,0.241922f,0.258819f,0.275637f,0.292372f,0.309017f,0.325568f,
0.342020f,0.358368f,0.374607f,0.390731f,0.406737f,0.422618f,0.438371f,0.453990f,0.469472f,0.484810f,
0.500000f,0.515038f,0.529919f,0.544639f,0.559193f,0.573576f,0.587785f,0.601815f,0.615661f,0.629320f,
0.642788f,0.656059f,0.669131f,0.681998f,0.694658f,0.707107f,0.719340f,0.731354f,0.743145f,0.754710f,
0.766044f,0.777146f,0.788011f,0.798636f,0.809017f,0.819152f,0.829038f,0.838671f,0.848048f,0.857167f,
0.866025f,0.874620f,0.882948f,0.891007f,0.898794f,0.906308f,0.913545f,0.920505f,0.927184f,0.933580f,
0.939693f,0.945519f,0.951057f,0.956305f,0.961262f,0.965926f,0.970296f,0.974370f,0.978148f,0.981627f,
0.984808f,0.987688f,0.990268f,0.992546f,0.994522f,0.996195f,0.997564f,0.998630f,0.999391f,0.999848f
};
/**
* Use the lookup table to return sine(angle) where angle is in radians
* to save flash this cheats and uses trig functions to only save
* 90 values
* @param[in] angle Angle in degrees
* @returns sin(angle)
*/
float sin_lookup_deg(float angle)
{
int i_ang = ((int32_t) angle) % 360;
if(i_ang > 270) // for 270 to 360 deg
return -sin_table[360 - i_ang];
else if (i_ang > 180) // for 180 to 270 deg
return -sin_table[i_ang - 180];
else if (i_ang > 90) // for 90 to 170 deg
return sin_table[180 - i_ang];
else // for 0 to 90 deg
return sin_table[i_ang];
return 0;
}
/**
* Get cos(angle) using the sine lookup table
* @param[in] angle Angle in degrees
* @returns cos(angle)
*/
float cos_lookup_deg(float angle)
{
return sin_lookup_deg(angle + 90);
}
/**
* Use the lookup table to return sine(angle) where angle is in radians
* @param[in] angle Angle in radians
* @returns sin(angle)
*/
float sin_lookup_rad(float angle)
{
int degrees = angle * 180.0f / M_PI;
return sin_lookup_deg(degrees);
}
/**
* Use the lookup table to return sine(angle) where angle is in radians
* @param[in] angle Angle in radians
* @returns cos(angle)
*/
float cos_lookup_rad(float angle)
{
int degrees = angle * 180.0f / M_PI;
return cos_lookup_deg(degrees);
}

39
flight/Libraries/math/sin_lookup.h Normal file
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@ -0,0 +1,39 @@
/**
******************************************************************************
* @addtogroup OpenPilot Math Utilities
* @{
* @addtogroup Sine and cosine methods that use a cached lookup table
* @{
*
* @file sin_lookup.h
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
* @brief Sine lookup table from flash with 1 degree resolution
*
* @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 SIN_LOOKUP_H
#define SIN_LOOKUP_H
float sin_lookup_deg(float angle);
float cos_lookup_deg(float angle);
float sin_lookup_rad(float angle);
float cos_lookup_rad(float angle);
#endif

1
flight/Modules/Stabilization/inc/relay_tuning.h
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@ -34,7 +34,6 @@
#ifndef RELAY_TUNING_H
#define RELAY_TUNING_H
int stabilization_relay_init();
int stabilization_relay_rate(float err, float *output, int axis, bool reinit);
#endif

44
flight/Modules/Stabilization/relay_tuning.c
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@ -32,40 +32,15 @@
*/
#include "openpilot.h"
#include "stabilization.h"
#include "stabilizationsettings.h"
#include "actuatordesired.h"
#include "ratedesired.h"
#include "relaytuning.h"
#include "relaytuningsettings.h"
#include "stabilizationdesired.h"
#include "attitudeactual.h"
#include "gyros.h"
#include "flightstatus.h"
#include "manualcontrol.h" // Just to get a macro
#include "CoordinateConversions.h"
#include "sin_lookup.h"
//! Private variables
static float *sin_lookup; // TODO: Move this to flash
static const int SIN_RESOLUTION = 180;
//! Private methods
static float sin_l(int angle);
#define MAX_AXES 3
int stabilization_relay_init()
{
sin_lookup = (float *) pvPortMalloc(sizeof(float) * SIN_RESOLUTION);
if (sin_lookup == NULL)
return -1;
for(uint32_t i = 0; i < 180; i++)
sin_lookup[i] = sinf((float)i * 2 * M_PI / 360.0f);
return 0;
}
/**
* Apply a step function for the stabilization controller and monitor the
* result
@ -129,8 +104,8 @@ int stabilization_relay_rate(float error, float *output, int axis, bool reinit)
uint32_t phase = 360 * dT / relay.Period[axis];
if(phase >= 360)
phase = 1;
accum_sin += sin_l(phase) * error;
accum_cos += sin_l(phase + 90) * error;
accum_sin += sin_lookup_deg(phase) * error;
accum_cos += sin_lookup_deg(phase + 90) * error;
accumulated ++;
// Make sure we've had enough time since last transition then check for a change in the output
@ -164,16 +139,3 @@ int stabilization_relay_rate(float error, float *output, int axis, bool reinit)
}
/**
* Uses the lookup table to calculate sine (angle is in degrees)
* @param[in] angle in degrees
* @returns sin(angle)
*/
static float sin_l(int angle) {
angle = angle % 360;
if (angle > 180)
return - sin_lookup[angle-180];
else
return sin_lookup[angle];
}

3
flight/Modules/Stabilization/stabilization.c
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@ -110,9 +110,6 @@ int32_t StabilizationStart()
// Create object queue
queue = xQueueCreate(MAX_QUEUE_SIZE, sizeof(UAVObjEvent));
// This prepares this optional algorithm
stabilization_relay_init();
// Listen for updates.
// AttitudeActualConnectQueue(queue);
GyrosConnectQueue(queue);