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Code Issues Releases Activity

Add the mag offset compensation into into the simulated sensor code

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This commit is contained in:
James Cotton 2012-07-26 21:00:30 -05:00
parent 880d58e4d9
commit 9f00eda1b4
1 changed files with 62 additions and 3 deletions
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65
flight/Modules/Sensors/simulated/sensors.c
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@ -63,6 +63,7 @@
#include "gpsvelocity.h"
#include "homelocation.h"
#include "magnetometer.h"
#include "magbias.h"
#include "ratedesired.h"
#include "revocalibration.h"
@ -87,6 +88,8 @@ static void simulateModelAgnostic();
static void simulateModelQuadcopter();
static void simulateModelAirplane();
static void magOffsetEstimation(MagnetometerData *mag);
static float accel_bias[3];
static float rand_gauss();
@ -114,6 +117,7 @@ int32_t SensorsInitialize(void)
GPSPositionInitialize();
GPSVelocityInitialize();
MagnetometerInitialize();
MagBiasInitialize();
RevoCalibrationInitialize();
return 0;
@ -503,6 +507,10 @@ static void simulateModelQuadcopter()
mag.x = homeLocation.Be[0] * Rbe[0][0] + homeLocation.Be[1] * Rbe[0][1] + homeLocation.Be[2] * Rbe[0][2];
mag.y = homeLocation.Be[0] * Rbe[1][0] + homeLocation.Be[1] * Rbe[1][1] + homeLocation.Be[2] * Rbe[1][2];
mag.z = homeLocation.Be[0] * Rbe[2][0] + homeLocation.Be[1] * Rbe[2][1] + homeLocation.Be[2] * Rbe[2][2];
// Run the offset compensation algorithm from the firmware
magOffsetEstimation(&mag);
MagnetometerSet(&mag);
last_mag_time = PIOS_DELAY_GetRaw();
}
@ -779,9 +787,10 @@ static void simulateModelAirplane()
static uint32_t last_mag_time = 0;
if(PIOS_DELAY_DiffuS(last_mag_time) / 1.0e6 > MAG_PERIOD) {
MagnetometerData mag;
mag.x = homeLocation.Be[0] * Rbe[0][0] + homeLocation.Be[1] * Rbe[0][1] + homeLocation.Be[2] * Rbe[0][2];
mag.y = homeLocation.Be[0] * Rbe[1][0] + homeLocation.Be[1] * Rbe[1][1] + homeLocation.Be[2] * Rbe[1][2];
mag.z = homeLocation.Be[0] * Rbe[2][0] + homeLocation.Be[1] * Rbe[2][1] + homeLocation.Be[2] * Rbe[2][2];
mag.x = 100+homeLocation.Be[0] * Rbe[0][0] + homeLocation.Be[1] * Rbe[0][1] + homeLocation.Be[2] * Rbe[0][2];
mag.y = 100+homeLocation.Be[0] * Rbe[1][0] + homeLocation.Be[1] * Rbe[1][1] + homeLocation.Be[2] * Rbe[1][2];
mag.z = 100+homeLocation.Be[0] * Rbe[2][0] + homeLocation.Be[1] * Rbe[2][1] + homeLocation.Be[2] * Rbe[2][2];
magOffsetEstimation(&mag);
MagnetometerSet(&mag);
last_mag_time = PIOS_DELAY_GetRaw();
}
@ -818,6 +827,56 @@ static float rand_gauss (void) {
return (v1*sqrt(-2.0 * log(s) / s));
}
/**
* Perform an update of the @ref MagBias based on
* Magnetometer Offset Cancellation: Theory and Implementation,
* revisited William Premerlani, October 14, 2011
*/
static void magOffsetEstimation(MagnetometerData *mag)
{
RevoCalibrationData cal;
RevoCalibrationGet(&cal);
// Constants, to possibly go into a UAVO
static const float MIN_NORM_DIFFERENCE = 50;
static float B2[3] = {0, 0, 0};
MagBiasData magBias;
MagBiasGet(&magBias);
// Remove the current estimate of the bias
mag->x -= magBias.x;
mag->y -= magBias.y;
mag->z -= magBias.z;
// First call
if (B2[0] == 0 && B2[1] == 0 && B2[2] == 0) {
B2[0] = mag->x;
B2[1] = mag->y;
B2[2] = mag->z;
return;
}
float B1[3] = {mag->x, mag->y, mag->z};
float norm_diff = sqrtf(powf(B2[0] - B1[0],2) + powf(B2[1] - B1[1],2) + powf(B2[2] - B1[2],2));
if (norm_diff > MIN_NORM_DIFFERENCE) {
float norm_b1 = sqrtf(B1[0]*B1[0] + B1[1]*B1[1] + B1[2]*B1[2]);
float norm_b2 = sqrtf(B2[0]*B2[0] + B2[1]*B2[1] + B2[2]*B2[2]);
float scale = cal.MagBiasNullingRate * (norm_b2 - norm_b1) / norm_diff;
float b_error[3] = {(B2[0] - B1[0]) * scale, (B2[1] - B1[1]) * scale, (B2[2] - B1[2]) * scale};
magBias.x += b_error[0];
magBias.y += b_error[1];
magBias.z += b_error[2];
MagBiasSet(&magBias);
// Store this value to compare against next update
B2[0] = B1[0]; B2[1] = B1[1]; B2[2] = B1[2];
}
}
/**
* @}
* @}