Handling And Stability Analysis And Simulation Of Fuzzy Control Research Of 4ws Vehicle

4WS (four wheel steering) is a new technology in vehicle systems. Compared with the current 2WS (two wheel steering),4WS has such advantages:when the vehicle turns at low velocity, it provides more smaller steering radius and improves the flexibility; when the vehicle turns at high speed, it improves the operation stability.Firstly, The 2DOF FWS vehicle model is built up,2DOF 4WS vehicle model also are built up. the two degrees of freedom four-wheel steering model applied front and rear wheel proportional control,the Yaw angular velocity and rear wheel proportional control and 2WS automobile were comparative analyzed.Secondly, through the learning ADAMS, The ADAMS/CAR internal module and the basis of known structural parameters of four-wheel steering cars revision, established the front suspension, rear suspension and steering system and Tire model, thus establishing the final 4WS virtual prototype model cars.Thirdly, In the virtual prototype model based on,4WS in the corner and step-sine circumstances transient response characteristics of the simulation test, using steady-state analysis of the Rotary test of the steady-state of 4WS.finally,analysis 4WS handling and stability to outside crosswind interferenceLastly, the sideslip angle feedback control fuzzy controller and the yaw velocity of vehicle feedback control fuzzy controller are designed. Three kinds of fuzzy control methods-sideslip feedback control, yaw velocity of vehicle control and sideslip and yaw velocity united feedback control are studied in this thesis, and compared proportional control of the ideal model. The results show that these three kinds of control methods can improve Manipulate stability of vehicle.