Simulation on Steering Stability of 4WS Tractor Semi-trailer

Based on the analysis of the steering performance, the objective of this paper is to present evidence for the tractor adopted the four-wheel steering (4WS) which can improve the handling and stability of tractor semi-trailer. The simplified single track model with 3 DOF for 4WS tractor semi-trailer has been constructed for dynamic simulation through time-domain response on the two states of small angle turning and straight driving. The analysis and simulations with Matlab show that this strategy can keep the vehicle yaw rate in a small scale. The comparisons are done with the front-wheel steering (FWS) and the 4WS for vehicle combination, the results verify that the 4WS has good effect on improving the high-speed stability and low-speed maneuverability of tractor semi-trailer.