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Code Issues Releases Activity

Try a different mag nulling algorithm.

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This commit is contained in:
James Cotton 2012-07-27 13:14:18 -05:00
parent 9f00eda1b4
commit abb0caa6bd
2 changed files with 108 additions and 0 deletions
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57
flight/Modules/Sensors/sensors.c
View File

@ -48,6 +48,7 @@
#include "pios.h"
#include "attitude.h"
#include "homelocation.h"
#include "magnetometer.h"
#include "magbias.h"
#include "accels.h"
@ -424,6 +425,7 @@ static void SensorsTask(void *parameters)
*/
static void magOffsetEstimation(MagnetometerData *mag)
{
#if 0
// Constants, to possibly go into a UAVO
static const float MIN_NORM_DIFFERENCE = 50;
@ -462,6 +464,61 @@ static void magOffsetEstimation(MagnetometerData *mag)
// Store this value to compare against next update
B2[0] = B1[0]; B2[1] = B1[1]; B2[2] = B1[2];
}
#else
static uint32_t call_count = 0;
MagBiasData magBias;
MagBiasGet(&magBias);
// Remove the current estimate of the bias
mag->x -= magBias.x;
mag->y -= magBias.y;
mag->z -= magBias.z;
if((call_count++ % 5) == 0) {
HomeLocationData homeLocation;
HomeLocationGet(&homeLocation);
AttitudeActualData attitude;
AttitudeActualGet(&attitude);
const float Rxy = sqrtf(homeLocation.Be[0]*homeLocation.Be[0] + homeLocation.Be[1]*homeLocation.Be[1]);
const float Rz = homeLocation.Be[2];
const float rate = cal.MagBiasNullingRate;
float R[3][3];
float B_e[3];
float xy[2];
float delta[3];
// Get the rotation matrix
Quaternion2R(&attitude.q1, R);
// Rotate the mag into the NED frame
B_e[0] = R[0][0] * mag->x + R[1][0] * mag->y + R[2][0] * mag->z;
B_e[1] = R[0][1] * mag->x + R[1][1] * mag->y + R[2][1] * mag->z;
B_e[2] = R[0][2] * mag->x + R[1][2] * mag->y + R[2][2] * mag->z;
float cy = cosf(attitude.Yaw * M_PI / 180.0f);
float sy = sinf(attitude.Yaw * M_PI / 180.0f);
xy[0] = cy * B_e[0] + sy * B_e[1];
xy[1] = -sy * B_e[0] + cy * B_e[1];
float xy_norm = sqrtf(xy[0]*xy[0] + xy[1]*xy[1]);
delta[0] = -rate * (xy[0] / xy_norm * Rxy - xy[0]);
delta[1] = -rate * (xy[1] / xy_norm * Rxy - xy[1]);
delta[2] = -rate * (Rz - B_e[2]);
if (delta[0] == delta[0] && delta[1] == delta[1] && delta[2] == delta[2]) {
magBias.x += delta[0];
magBias.y += delta[1];
magBias.z += delta[2];
MagBiasSet(&magBias);
}
}
#endif
}
/**

51
flight/Modules/Sensors/simulated/sensors.c
View File

@ -834,6 +834,7 @@ static float rand_gauss (void) {
*/
static void magOffsetEstimation(MagnetometerData *mag)
{
#if 0
RevoCalibrationData cal;
RevoCalibrationGet(&cal);
@ -875,6 +876,56 @@ static void magOffsetEstimation(MagnetometerData *mag)
// Store this value to compare against next update
B2[0] = B1[0]; B2[1] = B1[1]; B2[2] = B1[2];
}
#else
HomeLocationData homeLocation;
HomeLocationGet(&homeLocation);
AttitudeActualData attitude;
AttitudeActualGet(&attitude);
MagBiasData magBias;
MagBiasGet(&magBias);
// Remove the current estimate of the bias
mag->x -= magBias.x;
mag->y -= magBias.y;
mag->z -= magBias.z;
const float Rxy = sqrtf(homeLocation.Be[0]*homeLocation.Be[0] + homeLocation.Be[1]*homeLocation.Be[1]);
const float Rz = homeLocation.Be[2];
const float rate = 0.01;
float R[3][3];
float B_e[3];
float xy[2];
float delta[3];
// Get the rotation matrix
Quaternion2R(&attitude.q1, R);
// Rotate the mag into the NED frame
B_e[0] = R[0][0] * mag->x + R[1][0] * mag->y + R[2][0] * mag->z;
B_e[1] = R[0][1] * mag->x + R[1][1] * mag->y + R[2][1] * mag->z;
B_e[2] = R[0][2] * mag->x + R[1][2] * mag->y + R[2][2] * mag->z;
float cy = cosf(attitude.Yaw * M_PI / 180.0f);
float sy = sinf(attitude.Yaw * M_PI / 180.0f);
xy[0] = cy * B_e[0] + sy * B_e[1];
xy[1] = -sy * B_e[0] + cy * B_e[1];
float xy_norm = sqrtf(xy[0]*xy[0] + xy[1]*xy[1]);
delta[0] = -rate * (xy[0] / xy_norm * Rxy - xy[0]);
delta[1] = -rate * (xy[1] / xy_norm * Rxy - xy[1]);
delta[2] = -rate * (Rz - B_e[2]);
magBias.x += delta[0];
magBias.y += delta[1];
magBias.z += delta[2];
MagBiasSet(&magBias);
#endif
}
/**