ABSTRACT
Four different four-wheel steering systems have been investigated using analytical methods as well as computer simulations. Combining a simple model of a vehicle and an analytical driver model, increased stability behaviour of the overall driver-vehicle system has been found for three steering systems described in literature. These steering systems, however, result in vehicles with extreme understeer behaviour. Therefore a velocity dependent steering gear has been developed. This modification enables neutral steering characteristics independent of the position of the vehicle’s center of gravity. However, this system may produce stability problems due to Increased steering sensitivity.
The influence on the driving behaviour is additionally investigated using a complex vehicle model for a standard driving manoeuvre. In this case, the general purpose multibody program MEDYNA has been used to generate the equations of motion and perform computer simulations.
