Units of velocity feedback in diff_drive_controller

[macstepien]

Currently velocity feedback in diff_drive_controller is expected to be in m/s. Taking into account that position feedback is in radians and velocity commands are in rad/s it seems quite odd. I think that it will be better to also use rad/s there, following change should be enough:

odometry_.updateFromVelocity(
        left_feedback_mean * left_wheel_radius * period.seconds(), right_feedback_mean * right_wheel_radius * period.seconds(), time);

[destogl]

This sounds very plausible. You can open a PR and execute tests and see what they are saying. Maybe there are frew other places where this feedback is used and should be also adjusted.

[macstepien]

I executed tests locally, but noticed that even on the current master branch diff_drive_controller tests sometimes failed. It seems that correct_initialization_using_parameters is not really deterministic or there was something wrong with my setup (it would be nice to run CI on the PR that I created). Additionally I looked into this test and it doesn't look like my change will be executed there. I also checked if any other change will be necessary, but it seems that it was the only place.