Why does max steering angle exceed its max value?

Question

Hi,

When i set max steer angle to some value, while ackerman model is enabled, steering exceeds its max value. Can you please help me to understand why it does so?

Thanks in advance.

Answer 1

When Ackerman is enabled and the Ackerman Reference is set (the recommended default position is at the center of the rear axle) then the wheel in the inside of a turn steers a bit more and the wheel in the outside steers a bit less than the defined maximum steer angle. This solves the problem of the front wheels needing to trace out circles of different radii. More information:

https://en.wikipedia.org/wiki/Ackermann_steering_geometry

If you need to use Ackerman with a strict maximum angle you should reduce the configured maximum steer angle until the resulting maximum angle matches your value.