Skid Type Steering

Wheel ------ (Center)------ Wheel

can anyone help me with this dilema.

If I have a simulation of a tank type vehicle with skid type steering.. where the Wheels are controlled seperately... How can I calculate the Angle and location of the Vehicle Center if for instance I turn the Left wheel one revolution... Let assume that one revolution is arbitrarily on pixel of movement on the screen. The right wheel is stationary. Therefore the Center will shift up and to the right on the pivot of the right wheel.
If I then Turn the Right Wheel 10 Revolutions while the Left turns 10 Relovutions... this would be a straight line in the currently facing direction.

I hope this makes sense and that someone can help me.

Thanks,
Eric

if left wheel moves only: right wheel is the rotation center (-> set handle)

if right wheel moves only: left wheel is the rotation center

if both wheels move, the rotation center is at the "force center" of the steering. This means sum up force * position_vec and divide the sum by the total sum of the forces. Thats the rotation center if both wheels move.