car dynamic steering system

ahhm208

Hi,
I have these equations which represent the car steering angles and velocity, but I could not understand how do the operate.They are used for continus turning motion without keeping track of the car angle Beta. I would like some hints if any body is familiar with them or have any other similar equations or references:

PSI=arcsin( (v/d)*sin(Tyre Angle) );
course=Beta+PSI;
Gamma=Tyre Angle+course;

B=L*cos(Beta)+v*cos(Gamma)-L*cos(course);
C=cos(course);

rear velocity=B/C;

where
L : length between tyres.
Beta: is the slip angle( car angle)
PSI:is the angle below of Beta