| With the increase of expressway in our country, It is important to study the handling and stability of high-speedautomobile. Four-wheel-steering (4WS) as an advanced of active chassis control, which approaches to improving vehicle handling and stability, especially in the medium and high speed.Work principle and merit of 4WS system are summarized, and control strategies and development trends of 4WS system are described.From the simulation point of view, shortages of what has been studied on 4WS and the importance of co-simulation are pointed out. In order to create 4WS model, the design procedures of digital model based on virtual prototype technology are studied. This study reviews the methods utilized in ADAMS, including coordinate choice, the system equation constructions and solutions.The critical steps how to create subsystems in ADAMS/Car template and the descriptions of communicator in the ADAMS/Car researched. Then, a new 4WS vehicle model is set up means revamping a'FWS (Front-wheel-steering).The new model includes suspension system, steering system, nonlinear tire model and Car body etc.A fuzzy adaptive PID controller (FAPID) and its design method are presented in this paper. The fuzzy PID controller is designed in two steps which are relatively independent:The method of designing fuzzy PID controller is easy and it can be applied conveniently in engineering. Simulation results show that the robustperformance of fuzzy PID control 4WS is better,overshoot is smaller,ability of rejecting disturbance is larger than no control system. It resolves the conflict between response speed and smaller overshoot.Doing co-simulation based on ADAMS,Matlab/Simulink,control method is fuzzy PID, system.The response curves of evaluating handling stability obtained according to co-simulation results of step steering maneuvers. It offers a convenient method for studying the movement of 4WS, single lane change maneuvers. It provides theoretical basis for developing 4WS physical vehicle rapidly.
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