Add vehicle model module for converting wheel encoder counts into body velocities

[AmeliaEScott]

Describe problem solved by the proposed feature
Wheel encoder support is being worked on here. The end result of this drive will be a uORB topic that publishes raw encoder data. This data must be converted to velocities to be used by the EKF2 module, but this is not trivial: Different rovers can have different wheel configurations and different number and placement of encoders.

Describe your preferred solution
A new module should be created which handles different rover configurations, and is easily extensible so that it can be easily updated to handle new configurations.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.

[avielm]

is there any work on this?

[dagar]

is there any work on this?

The Roboclaw driver in current PX4 publishes odometry data.

PX4-Autopilot/src/drivers/roboclaw/RoboClaw.cpp

Lines 223 to 229 in f571b29

	for (int i = 0; i < 2; i++) {
	_wheelEncoderMsg[i].timestamp = encoderTaskLastRun;
	_wheelEncoderMsg[i].encoder_position = _encoderCounts[i];
	_wheelEncoderMsg[i].speed = _motorSpeeds[i];
	_wheelEncodersAdv[i].publish(_wheelEncoderMsg[i]);

The next step is actually consuming it in the ekf2, including adding appropriate configurable physical quantities for the wheels.