The Research On ABS Simulation Based On Fuzzy Control

Anti-lock braking system is an important device to improve the active safety of vehicle. Today with the improved development of the vehicle, ABS is applied wider and wider. The ABS automatically controls the brake torque of each wheel to prevent it from getting locked in the process of braking. This is important to improve the stability, steerablity and brake efficiency of the vehicle during braking and maintain the safety to the driver and passengers.First of all , the theory of ABS was expounded which include working theory ,structure and primary control strategies(threshold control, PID control, sliding mode control, fuzzy control) at present. Then ABS braking performance evaluation method was introduced.As for the vehicle models which were built in ABS research field to be simple presently, the research on Anti-lock braking system based on multi-body dynamics and intelligent control theory were presented in this paper. A multi-body vehicle dynamic model was built by ADAMS/CAR, the model included front and rear suspension system, engine system, steering system, antiroll system, brake system and vehicle body model. The multi-body model also considered the nonlinear characteristics of the tire ,bushing, spring and damper and can accurately express the dynamics performance of the vehicle.In addition, a fuzzy control model of ABS was built by Matlab fuzzy toolbox, and the ABS control model was built in the Matlab/Simulink. The mechanical model and the contrl model were integrated and co-simulated by the interface of ADAMS/Control, the simulation conditions were decided according to the ABS performance requirements of GB(13594-92), the results of simulation were compared with the results of braking without ABS. At last, another control method--threshold control model was built, and the simulation results of the two control strategies were compared. The analysis results showed the advantage of vehicle ABS based on fuzzy control and indicated fuzzy control has better stability and robustness.