The Research Of Four Wheel Steering Vehicle Based On ADAMS Simulation

Fractional calculus theory is the hot topics in recent years. The main work of this paper is designing a new control strategy for the four wheel steering car on the basis of fractional calculus theory, simulating the virtual dynamic model in ADAMS, and evaluating the control strategy influence on handling stability, specifics are as follows.An outline of the dynamic emulate software ADAMS and mathematical software MATLAB/Simulink is presented, and the theoretical principle of the ADAMS is introduced specially4WS mathematical model with two Degree of Freedom is built, three type of the tire model is present, and the physical significance of the parametric in the model is illustratedA virtual dynamic model of 4WS vehicle is built in the ADAMS based on Car Module which is specially designed for car simulation. The virtual model consists of vehicle body subsystem, suspension subsystem, tire subsystem, and steering subsystem. And the control algorithm is set in the control toolbox to control the rear wheel, make it turn as we designed.The concept of fractional calculus and genetic algorithm were introduced, and proposed a new 4WS vehicle control strategy(based on reference model yaw-rate tracking)which contain fractional PID control in controller, at last get the parameter of PID through the genetic algorithmAccording to road vehicle ISO test standard, studies transient state and steady state response characteristics of the car with the 4 wheel steering control method.The results indicate that reference model yaw rate tracking control strategy could improve the handling stability of the vehical, and the control system has good robustness.