The Research Of Vehicle Dynamics Stability Control Based On The Fuzzy Control

While cars are driven during turning on the road with low adhesion coefficient or in high speed, the lateral force of the tyre usually attained to the physical limit and the vehicle dynamics stability will be lost because of the exoteric disturbance or cornering, so the traffic accidents frequently happen. The handling and the stability can be improved in limit cornering by using the VDC. In this paper, according to the current, research state of the VDC methods, the fuzzy control theory is applied in the research of the VDC, and it supplies the control methods for the future developments of the true system.The seven freedoms driver-vehicle closed loop system model is first built and the simulation and the proof for the model are made to provide the correct models for the VDC researches in this paper. Secondly the control strategies that can improve the vehicle dynamics stability by using single wheel braking are brought forward according to the basic theory of the VDC. Then due to nonlinear and time-varying property of the VDC system, the two control ways are adopted: one is the parameter self-turning fuzzy-PI control that utilizes the yaw rate as the only variable. The other is the fuzzy variable structure control that utilizes the yaw and the slip angel as the control variable. Moreover several typical operation modes are simulated and analyzed by using the two control ways, and the result shows that the parameter self-turning fuzzy-PI control is better than the general PID control in robustness and self-adaptability and the control way can effectively improve the VDC performance. The fuzzy variable structure control utilizes the yaw and the slip angel as the control variable, and they are the two major parameters describing the dynamics performance, so the dynamics stability should be comprehensively and reasonably controlled and it is a better control methods of vehicle dynamics stability control.