Study And Simulation On Automotive Anti-Lock Braking System Based On AMESim

With the development of the automobile industry of our country, , it is inevitable to proceed independent development of automotive key parts and the safety in braking has been brought into focus. Anti-lock braking system associate with the safety in braking, also seriously restrict the development of ESP and the independent development of the entire vehicle. Basing on the study of the main methods applied in ABS, a new and practical strategy was adopted, the self-optimizing control strategy which provided a new approach to the research of ABS.Precise master brake cylinder model, wheel brake cylinder model, hydraulic control unit(HCU) of ABS model were established utilizing the hydraulic modeling advantages of the AMESim software. Vehicle dynamic model and tyre model were established in Matlab/Simulink.Firstly, A single-wheel model of ABS with PID controller was established, using PWM signal control the high-speed switch valves of the HCU, and got a ideal control result. Basing on the analyse of the ideal control result, the deeply study of the self-optimizing control theory and the principle of ABS, according to the principle of successive measurement and successive comprehension of self-optimizing control theory, adopted the heuristic step combined with the adjusting step, applied self-optimizing control theory to the ABS control and established the control strategy model using stateflow finite state machine. The single-wheel self-optimizing ABS model was established using AMESim combined with Matlab/Simulink, considering the longitudinal load transfer, two-wheel-two-channel ABS model was established, also considering the longitudinal load transfer, the lateral load transfer and the brake performance on bisectional roads, four-wheel-four-channel ABS model was established. The simulation experiments on dry road surface, wet road surface, icy road surface, docking roads and bisectional roads were carried out using AMESim Matlab/Simulink interface and obtained better simulation results.It can be certified through the simulation experiment results that self-optimizing ABS can avoid the wheel locked on any road surface, realize the road self-identification function, regulate the brake torque intelligently according to the change of the road surface, search the optimal point of the slip ratio and maintain the system working around the optimal point making full use the adhesion ability of the road surface and increase the brake performance. Therefore self-optimizing ABS possess practical value and deserve further study.