A non-linear dynamic approach to the motion of four-wheel-steering vehicles under various operation conditions

Abstract

This research aims to analyse systematically the non-linear dynamic behaviour of four-wheel-steering (4WS) vehicles. A practical non-linear dynamic model of multiple degrees of freedom for 4WS vehicles is established. The non-linear model presented is shown to be feasible for the vehicles under normal and the other operation manoeuvres. Compared with those of documented investigations, this model may be employed to analyse the motions of the vehicle and motions of the vehicle wheels in turning and braking processes together with the consideration of the effects of air drag and wind. Numerical simulation for the motion of the 4WS vehicles under various operation manoeuvres is performed with the model established. Comparison of the behaviours of 4WS and two-wheel-steering vehicles is also presented with respect to the inputs on the steering system, the manoeuvrability, the stability, and the relationship between the steering phase and vehicle speed.