This estimate doesn't converge to the true yaw but can be used as a
more consistent but drifting heading source.
It can be used by a setpoint generator to adjust its heading setpoint
while the true yaw estimate is converging in order to keep a constant
course over ground.
- when GNSS is used require low mag heading innovations during
horizontal acceleration (yaw observable) to validate the mag
- only fuse mag heading just enough to constrain the yaw estimate
variance to a sane value. Leave enough uncertainty to allow for a
correction when the yaw is observable through GNSS fusion
- split mag_3d into new standalone mag fusion and mag fusion allowed to update all states (full mag_3d)
- new dedicated control logic for mag/mag_3d fusion and standalone mag heading fusion
- if WMM available use for mag_I and mag_B init
- mag states reset if external yaw reset (yaw estimator, GPS yaw, etc)
- mag reset if declination changed (eliminate _mag_yaw_reset_req)
- mag fusion (but not mag_hdg or mag_3d) can be active during gps_yaw or ev_yaw (if yaw aligned north)
Co-authored-by: bresch <brescianimathieu@gmail.com>
* ekf2-test: remove outdated codegen comparison
The definition of states changed so the comparison with the old
derivation cannot work anymore.
---------
Co-authored-by: bresch <brescianimathieu@gmail.com>
This can be useful if using a full EV + GNSS setup and you start indoors, then fly outside. Once GPS is good and the only missing requirement is yaw alignment the yaw estimator reset is performed and EV yaw will automatically stop itself.
There is no reason to contrsain the position uncertainty, estpecially
when flying with velocitiy aiding only.
Note that all the variances are already contrained to sane values at the
end of the covariance prediction
- set vision attitude error filter uninitialized if vision data stops
- ev error filter is only compiled when ev config is selected
Co-authored-by: bresch <brescianimathieu@gmail.com>
There is some actual changes because the earth mag field states are now
reset using the WMM when available. In the replay log, the measured mag
field does not match the WMM and this is why there is a large diff. It
is however more correct now than before.
- since last_us is set to 0 every time the bias is not observable, the
total time was also reset -> needed 30 consecutive seconds in mag 3D
to be declared "stable"
- after landing, the mag_aligned_in_flight flag is reset. Using this for
bias validity makes it invalid before we have a chance to save it to
the calibration.
Opt flow raw innovations can be really large on ground due to the small
distance to the ground (vel = flow / dist). To make the pre-flight check
more meaningful, scale it with the current distance.
bresch