- a growing number of samples come into the backend with the time
already delayed (sensor's interrupt setting timestamp sample)
- if the incoming timestamp is already delayed then the new data checks
(relative to latest IMU) can be slightly wrong
- handle almost all timestamps and checks on delayed time horizon,
except for explicit checks of new samples
- isRecent() and isTimedOut() helpers use delayed time
- add new isNewestSampleRecent() used for checking the incoming
timestamp of the incoming (adjusted) data
Also remove the legacy "range aid" than can be achieved by setting the
height reference to range finder and the range finder control parameter
to "conditional".
Conditional range aiding cal also be set when the height reference isn't
the range finder. This prevents the ratchetting effect due to switching
between references.
Instead of having a single height source fused into the EKF and the
other ones "waiting" for a failure or the primary sensor, fuse all
sources in EKF2 at the same time. To prevent the sources from fighting against each
other, the "primary" source is set as reference and the other ones are
running a bias estimator in order to make all the secondary height
sources converge to the primary one.
If the reference isn't available, another one is automatically selected
from a priority list. This secondary reference keeps its current bias
estimate but stops updating it in order to be the new reference as close
as possible to the primary one.
- move vehicle at reset detection ekf2 -> land_detector
- ekf_unit: reduce init period
- Fake fusion is when at rest is quite strong and makes the variance reduce rapidly. Reduce the amount of time we wait before checking if the variances are still large enough.
- ekf_unit: reduce minimum vel/pos variance required after init
- Fake pos fusion has a low observation noise, making the vel/pos variances reduce quickly.
Co-authored-by:: bresch <brescianimathieu@gmail.com>
- introduces new parameter EKF2_PREDICT_US to configure the filter
update period in microseconds
- actual filter update period will be an integer multiple of IMU
Daniel Agar