Calculation of vehicle_velocity_converter package covariance parameters

[meliketanrikulu]

While testing ekf with autoware universe, we saw that there was a small noise (flicker) problem in the base_link when the vehicle was stationary, and the source of the problem was related to the covariance values in the vehicle velocity converter package
we detected.The problem was solved when we set the covariance values in the vehicle velocity converter to 0. Could you share with us how you calculated these covariance values?
Considering that these values will change according to the vehicle, we think that the covariance matrix should be calculated instead of using the default value. What are your thoughts on this?

[YamatoAndo]

@kminoda Could you please answer this question?

[kminoda]

@meliketanrikulu Thank you for sharing your issue!

May I ask why you want to mitigate the small flicker in the base_link?

While testing ekf with autoware universe, we saw that there was a small noise (flicker) problem in the base_link when the vehicle was stationary, and the source of the problem was related to the covariance values in the vehicle velocity converter package we detected.

(Setting aside what is the cause of the problem,) IMHO you should approach the problem in a way other than changing the value of velocity covariance. The covariance value (0.04 & 0.01) is just a sample value, but somewhat a reasonable value as far as we have tested on our various vehicles, and it is likely that the same applies to your vehicle, too.
I believe we should deal with the flickering problem by adding some postprocessing after EKF (for example like stop_filter).

Could you share with us how you calculated these covariance values?
Considering that these values will change according to the vehicle, we think that the covariance matrix should be calculated instead of using the default value. What are your thoughts on this?

The parameter set in the config file you've shared is merely a sample value (for example in case you need a sample config file to launch the package independently for debugging). So yes, it should be (and intended to be) calibrated beforehand for each vehicle or each type of vehicle when you integrate Autoware to any of your vehicles.

FYI, TIER IV has just made it public a calibration tool for estimating the value (see here for detail).