With the help of such elementary considerations it may be possible to answer questions related to the suitability of a particular direction to the steering angle on the rear axle, but will however, not help in the determination of a suitable functional relation between the steering angle on the front axle and the steering angle on the rear axle.
The following consideration, in the least, provides a theoretically meaningful control strategy for rear-axle steering: The approach towards the stability limits in relation to the driving dynamics of a motor vehicle is usually characterized by significant vehicle sideslip angles being reached very rapidly.
In these situations, the driver's reflexes are often overtaxed, since these vehicle movements along with the steering inputs required to stabilize them are not within the scope of stimulus-response mechanisms experienced by him in everyday traffic /11/.
Therefore, the objective in this case is to fully compensate the vehicle sideslip angles by means of rear-axle steering in a speed range which is of significance from the point of view of driving dynamics and thus to offer the driver a familiar steering behavior which remains virtually unchanged at the stability limit.
The basic derivation of the required functional relation between front and rear steering angles can be determined using the linearized single-track vehicle model.