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AP_InertialSensor: use accel instance max abs offset instead of a constant value

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The calibration on LSM9DS0 was giving offsets between 4.0 and 4.2 on x-axis and
around 3.6 on y-axis. It turned out that those offsets were actually right.

The maximum absolute values of calibration offset should be a sensor
characteristic rather than a constant value for all sensors.

The constant value previously used (3.5 m/s/s for all axes) is set here as a
default maximum absolute calibration offset for every instance to keep it
working.
This commit is contained in:
Gustavo Jose de Sousa 2015-06-09 17:47:16 -03:00 committed by Andrew Tridgell
parent 623c5f0713
commit c340e072f2
4 changed files with 32 additions and 5 deletions
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19
libraries/AP_InertialSensor/AP_InertialSensor.cpp
View File

@ -301,6 +301,8 @@ AP_InertialSensor::AP_InertialSensor() :
#if INS_VIBRATION_CHECK
_accel_clip_count[i] = 0;
#endif
_accel_max_abs_offsets[i] = Vector3f(3.5f, 3.5f, 3.5f);
}
memset(_delta_velocity_valid,0,sizeof(_delta_velocity_valid));
memset(_delta_angle_valid,0,sizeof(_delta_angle_valid));
@ -578,7 +580,11 @@ bool AP_InertialSensor::calibrate_accel(AP_InertialSensor_UserInteract* interact
continue;
}
bool success = _calibrate_accel(samples[k], new_offsets[k], new_scaling[k], saved_orientation);
bool success = _calibrate_accel(samples[k],
new_offsets[k],
new_scaling[k],
_accel_max_abs_offsets[k],
saved_orientation);
interact->printf_P(PSTR("Offsets[%u]: %.2f %.2f %.2f\n"),
(unsigned)k,
@ -977,7 +983,9 @@ bool AP_InertialSensor::_check_sample_range(const Vector3f accel_sample[6], enum
// accel_scale are output from the calibration routine
// returns true if successful
bool AP_InertialSensor::_calibrate_accel(const Vector3f accel_sample[6],
Vector3f& accel_offsets, Vector3f& accel_scale,
Vector3f& accel_offsets,
Vector3f& accel_scale,
Vector3f& max_abs_offsets,
enum Rotation rotation)
{
int16_t i;
@ -1034,8 +1042,11 @@ bool AP_InertialSensor::_calibrate_accel(const Vector3f accel_sample[6],
if( accel_scale.is_nan() || fabsf(accel_scale.x-1.0f) > 0.1f || fabsf(accel_scale.y-1.0f) > 0.1f || fabsf(accel_scale.z-1.0f) > 0.1f ) {
success = false;
}
// sanity check offsets (3.5 is roughly 3/10th of a G, 5.0 is roughly half a G)
if( accel_offsets.is_nan() || fabsf(accel_offsets.x) > 3.5f || fabsf(accel_offsets.y) > 3.5f || fabsf(accel_offsets.z) > 3.5f ) {
if (accel_offsets.is_nan() ||
fabsf(accel_offsets.x) > max_abs_offsets.x ||
fabsf(accel_offsets.y) > max_abs_offsets.y ||
fabsf(accel_offsets.z) > max_abs_offsets.z) {
success = false;
}

9
libraries/AP_InertialSensor/AP_InertialSensor.h
View File

@ -248,7 +248,11 @@ private:
// original sketch available at http://rolfeschmidt.com/mathtools/skimetrics/adxl_gn_calibration.pde
// _calibrate_accel - perform low level accel calibration
bool _calibrate_accel(const Vector3f accel_sample[6], Vector3f& accel_offsets, Vector3f& accel_scale, enum Rotation r);
bool _calibrate_accel(const Vector3f accel_sample[6],
Vector3f& accel_offsets,
Vector3f& accel_scale,
Vector3f& max_abs_offsets,
enum Rotation rotation);
bool _check_sample_range(const Vector3f accel_sample[6], enum Rotation rotation,
AP_InertialSensor_UserInteract* interact);
void _calibrate_update_matrices(float dS[6], float JS[6][6], float beta[6], float data[3]);
@ -292,6 +296,9 @@ private:
AP_Vector3f _accel_offset[INS_MAX_INSTANCES];
AP_Vector3f _gyro_offset[INS_MAX_INSTANCES];
// accelerometer max absolute offsets to be used for calibration
Vector3f _accel_max_abs_offsets[INS_MAX_INSTANCES];
// temperatures for an instance if available
float _temperature[INS_MAX_INSTANCES];

6
libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
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@ -78,6 +78,12 @@ void AP_InertialSensor_Backend::_publish_accel(uint8_t instance, const Vector3f
}
}
void AP_InertialSensor_Backend::_set_accel_max_abs_offset(uint8_t instance,
const Vector3f offset)
{
_imu._accel_max_abs_offsets[instance] = offset;
}
// set accelerometer error_count
void AP_InertialSensor_Backend::_set_accel_error_count(uint8_t instance, uint32_t error_count)
{

3
libraries/AP_InertialSensor/AP_InertialSensor_Backend.h
View File

@ -73,6 +73,9 @@ protected:
// rotate accel vector, scale, offset and publish
void _publish_accel(uint8_t instance, const Vector3f &accel, bool rotate_and_correct = true);
// set accelerometer max absolute offset for calibration
void _set_accel_max_abs_offset(uint8_t instance, const Vector3f offset);
// publish a temperature value
void _publish_temperature(uint8_t instance, float temperature);