Refactor odometry class of steering controllers library

[christophfroehlich]

Background

The SteeringOdometry class handles forward and inverse kinematics.
This leads to code like this one, which is confusing (why should odometry be used for calculating commands).

    auto [traction_commands, steering_commands] = odometry_.get_commands(
      reference_interfaces_[0], reference_interfaces_[1], params_.open_loop,
      params_.reduce_wheel_speed_until_steering_reached);

Suggestion: Split the class in forward and inverse kinematics, maybe inheriting from a common parameter class.

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[nakul-py]

Hey @christophfroehlich
I want to work on this issue.

[christophfroehlich]

What I haven't mentioned in the first idea there: We have to deprecate the old library, because it is released into a stable distro (Jazzy) and we can't break API without notice there.

1. The easiest solution is just to rename the class SteeringOdometry (incl. namespace and filenames) to something including FK and IK, maybe just steering_kinematics. Then add an alias in the old filenames including a compile-time warning that this is deprecated, see examples for this.
2. Same can be done with splitting SteeringOdometry into two, but maybe this is not necessary if the naming is clear.

[bhagyeshagresar]

Hello @christophfroehlich and @nakul-py ! Is this issue still open for contribution?

[christophfroehlich]

The linked PR #1475 is stale, @bhagyeshagresar you are welcome to contribute. Please consider my comment above, and the comments in the linked PR. Could you maybe describe your proposal first in this issue, so we can discuss it before you start implementing it?

[bhagyeshagresar]

Hello @christophfroehlich. I was gonna follow along with your comments for the solution but let me take some time to go through it. I need to get a little more familiar with the project.

[christophfroehlich]

The simplest approach would be just to rename odometry to kinematics, which is then valid for forward kinematics (odometry calculation) and inverse kinematics (getting commands).
For deprecation, I suggest renaming the files, adding a new steering_odometry.hpp file pointing to the new header and with a compile time warning if it is used. In this file an alias for the symbols like SteeringOdometry to SteeringKinematics will do the job.