Abstract
A symbolic-numerical approach is used to analyse the response ofa road vehicle equipped with a four-wheel steering system using a nonlinear model with a low number of DOF. A quadratic law to control the rear wheels is derived in closed-form, which shows better characteristics under steering and braking manoeuvres than its linear equivalent. The stability of the straight line motion for four-wheel steering and front-wheel steering vehicles is analysed using symbolic manipulation to characterize the stability in terms of eigenvalues computed in closed-form. This approach can provide formulas to assess dynamic stability and significantly enhance the vehicle design process. (A)