Research On Fuzzy Control Of ABS Based On Co-simulation

In recent years, with the rapid development of the domestic auto industry, the soaring automobile quantities and worse traffic condition request better braking performance of vehicles. As the most widely used and most successful electronic assistant device in the automobile, Anti-locked Braking System is proved able to prevent wheels from braking, thus the braking performance is improved.Firstly the force between the wheels and the ground during the Braking process is analyzed in this paper, and the influence between slip ratio and the brake performance is clarified too, and then prompt the structure and operating principle of ABS. An idea of applying fuzzy control to the ABS is proposed base on comparing advantages and disadvantages of several kinds of control algorithm of ABS, then analysis and prove it by co-simulation.As for the single wheel model frequently used for ABS research is too simple, a more accurate dynamical model is built in Adams/Car, included subsystems as front and rear suspension, steer system, brake system and powertrain. etc, and the elasticity of flexible components,such as tires, springs and bushes is taken in account in this model, the brake system model is modified so it can receive the control signal and work as ABS system.A fuzzy controller for ABS is developed by the fuzzy toolbox of Matlab base on study related theory of fuzzy control. The fuzzy controller and the dynamical model are contacted through Adams/Controls, and the whole control model is built in Matlab/Simulink, then the brake process is analyzed by simulation.An evaluation criterion is formulated refer the National Standards about the performance of ABS and several subjects is concerned. The model is simulated on two different roads because the vehicle brake on various kinds of road, and a high adhesion road and an opposite adhesion road are designed.The result show that the brake performance of the vehicle is promoted on both kinds of roads after the fuzzy control is used in the ABS. A frequently-used logic moedl is designed and simulated in the same condition for a more comprehensive evaluation, after simulating in the same condition and dynamical model, comparing the results of the two control algorithms, we come to a conclusion that the fuzzy control is more stable and better robustness.