ackermann_steering_controller: wheel_radius

[iliabaranov]

Hello all,

The documentation http://wiki.ros.org/ackermann_steering_controller states:

wheel_radius (double)
Radius of the wheels. It is expected they all have the same size. The ackermann_steering_controller will attempt to read the value from the URDF if this parameter is not specified.

Any particular reason for this? Tractors (for example) tend to have much smaller steering wheels. But even regular cars can have different wheel sizes.
Perhaps this is something I could extend/add to?

Best wishes,
Ilia B.

[bmagyar]

happy to incorporate this change, there's no strong reason for even-sized wheels

[iliabaranov]

First attempt here, I welcome feedback :)
#575