* ekf_control: Inhibit mag fusion when field magnitude is large
Move mag inhibition check in separate function
* ekf_control: pull out of functionalities out of controlMagFusion
- yaw abd mag bias observability checks
- mag 3D conditions
- load mag covariances
- set and clear mag control modes
* ekf_control: refactor mag heading/3D start/stop.
Move mag declination, mag 3d and mag heading fusion out of the main function
* ekf_control: extract mag yaw reset and mag declination fusion requirements
* ekf_control: use WMM in isStronMagneticField for mag fusion inhibition
- Correct units of WMM strength table
* ekf_control: extract mag_state_only functionality of AUTOFW (VTOL custom)
Also split inAirYawReset from onGroundYawReset
* ekf_control: extract mag automatic selection
- transform if-else into switch-case for parameter fusion type selection
* ekf_control: extract run3DMagAndDeclFusion, reorganize functions, fix
flag naming in Test script
* ekf_control: do not run mag fusion if tilt is not aligned.
Reset some variables on ground even if mag fusion is not running yet. It
could be that it runs later so we need to make sure that those variables
are properly set.
* ekf_control: move controlMagFusion and related functions to mag_control.cpp
* ekf control: check for validity of mag strength from WMM and falls back
to average earth mag field with larger gate if not valid
* ekf control: remove evyaw check for mag inhibition
* ekf control: change nested ternary operator into if-else if
* Ekf: create AlphaFilter template class for simple low-pass filtering
0.1/0.9 type low-pass filters are commonly used to smooth data, this
class is meant to abstract the computation of this filter
* ekf control: reset heading using mag_lpf data to avoid resetting on an outlier
fixes ecl issue #525
* ekf control: replace mag_states_only flag with mag_field_disturbed and
add parameter to enable or disable mag field strength check
* ekf control: remove AUTOFW mag fusion type as not needed This was implemented for VTOL but did not solve the problem and should not be used anymore
* ekf control: use start/stop mag functions everywhere instead of setting the flag
* ekf control: Run mag fusion depending on yaw_align instead of tilt_align
as there is no reason to fuse mag when the ekf isn't aligned
* AlphaFilter: add test for float and Vector3f
The quaternion to inverse rotation matrix function has been updated so that the rotation it produces is the inverse to that produced by the matrix library and the the inverse of the quaternion is uses. This function is now used to directly calculate an inverse rotation matrix rather than calculating the forward rotation and then transposing it.
- calculate a theoretical value based on the knowledge of the direction
and strength of the magnetic field vector and X/Y sensor measurements
- needs knowledge about location on earth to work
Fusion with large initial magnetometer biases errors can result in the the NE earth field states reducing in magnitude and effectively flipping sign.
EKF: Move declination state limiting into a separate function
EKF: Limit NE mag states after each 3-axis mag fusion
EKF: Fix bug in mag field strength look-up scale factor
Ensures that each time the earth field covariance and variance data is reset, that the off-diagonal elements containing earth field declination angle certainty is restored.
Moves calculation only required for mag heading fusion into the if (_control_status.flags.mag_hdg) branch
When using EV yaw, the observed yaw angle is calculated directly from the EV quaternions using derived expressions from references in code comments.
Everywhere where KHP is used, it is first completely reset, thus making
it unnecessary to keep it as a class member.
This saves 2.3KB RAM.
Stack sizes don't need changing, since there is already a function
Ekf::predictCovariance(), which needs around 3KB of stack and is called
close to where the fuse* functions are called.
Perform the innovation consistency check on all axes first and exit if any axis fails. Reduces the likelihood of bad magnetometer data corrupting the attitude estimates.
The code fragments for the magnetometer fusion have been refreshed from the auto-coder.
Explicit floating point types used for constants.
The 3x24 observation Jacobian has been replaced with a 1x24 that is updated each axis iteration to save memory.
The covariance was not being updated with the observation from one axis before the innovation variance was calculated for the next axis. This results in greater weighting on measurements for subsequent axes.
