EKF: Ensure yaw gets reset when declination is set

This commit is contained in:
Paul Riseborough
2018-11-15 07:16:31 +11:00
committed by Paul Riseborough
parent 68a3cbc368
commit 4657a9cd21
4 changed files with 53 additions and 39 deletions
+43 -39
View File
@@ -545,6 +545,11 @@ bool Ekf::realignYawGPS()
// Reset heading and magnetic field states
bool Ekf::resetMagHeading(Vector3f &mag_init)
{
// don't reseet twice on the same frame
if (_imu_sample_delayed.time_us == _flt_mag_align_start_time) {
return true;
}
if (_params.mag_fusion_type >= MAG_FUSE_TYPE_NONE) {
// do not use the magnetomer and deactivate magnetic field states
zeroRows(P, 16, 21);
@@ -701,51 +706,50 @@ bool Ekf::resetMagHeading(Vector3f &mag_init)
delta_ang_error(1) = scalar * q_error(2);
delta_ang_error(2) = scalar * q_error(3);
// update quaternion states
_state.quat_nominal = quat_after_reset;
// update the quaternion state estimates and corresponding covariances only if the change in angle has been large
// record the state change
_state_reset_status.quat_change = q_error;
// update transformation matrix from body to world frame using the current estimate
_R_to_earth = quat_to_invrotmat(_state.quat_nominal);
// reset the rotation from the EV to EKF frame of reference if it is being used
if ((_params.fusion_mode & MASK_ROTATE_EV) && (_params.fusion_mode & MASK_USE_EVPOS) && !_control_status.flags.ev_yaw) {
resetExtVisRotMat();
}
// update the yaw angle variance using the variance of the measurement
if (!_control_status.flags.ev_yaw) {
// using error estimate from external vision data
angle_err_var_vec(2) = sq(fmaxf(_ev_sample_delayed.angErr, 1.0e-2f));
} else if (_params.mag_fusion_type <= MAG_FUSE_TYPE_AUTOFW) {
// using magnetic heading tuning parameter
angle_err_var_vec(2) = sq(fmaxf(_params.mag_heading_noise, 1.0e-2f));
}
// update the covariances only if the change in angle has been large to avoid unnecessary
// manipulation of the covariance matrix that can temporarily reduce filter performance
if (delta_ang_error.norm() > math::radians(15.0f)) {
// update quaternion states
_state.quat_nominal = quat_after_reset;
// record the state change
_state_reset_status.quat_change = q_error;
// update transformation matrix from body to world frame using the current estimate
_R_to_earth = quat_to_invrotmat(_state.quat_nominal);
// reset the rotation from the EV to EKF frame of reference if it is being used
if ((_params.fusion_mode & MASK_ROTATE_EV) && (_params.fusion_mode & MASK_USE_EVPOS) && !_control_status.flags.ev_yaw) {
resetExtVisRotMat();
}
// update the yaw angle variance using the variance of the measurement
if (!_control_status.flags.ev_yaw) {
// using error estimate from external vision data
angle_err_var_vec(2) = sq(fmaxf(_ev_sample_delayed.angErr, 1.0e-2f));
} else if (_params.mag_fusion_type <= MAG_FUSE_TYPE_AUTOFW) {
// using magnetic heading tuning parameter
angle_err_var_vec(2) = sq(fmaxf(_params.mag_heading_noise, 1.0e-2f));
}
// reset the quaternion covariances using the rotation vector variances
initialiseQuatCovariances(angle_err_var_vec);
// add the reset amount to the output observer buffered data
for (uint8_t i = 0; i < _output_buffer.get_length(); i++) {
// Note q1 *= q2 is equivalent to q1 = q2 * q1
_output_buffer[i].quat_nominal *= _state_reset_status.quat_change;
}
// apply the change in attitude quaternion to our newest quaternion estimate
// which was already taken out from the output buffer
_output_new.quat_nominal = _state_reset_status.quat_change * _output_new.quat_nominal;
// capture the reset event
_state_reset_status.quat_counter++;
}
// add the reset amount to the output observer buffered data
for (uint8_t i = 0; i < _output_buffer.get_length(); i++) {
// Note q1 *= q2 is equivalent to q1 = q2 * q1
_output_buffer[i].quat_nominal *= _state_reset_status.quat_change;
}
// apply the change in attitude quaternion to our newest quaternion estimate
// which was already taken out from the output buffer
_output_new.quat_nominal = _state_reset_status.quat_change * _output_new.quat_nominal;
// capture the reset event
_state_reset_status.quat_counter++;
return true;
}