The Theoretical Simulation And Implementation Of Vehicle Anti-lock Braking System (ABS)

Anti-locked brake system(ABS) is a essential initiative safety gear on modern vehicle guaranteeing safety running. To reveal the mechanism and performance of ABS, this paper chooses slip-ratio based anti-locked brake system as model. After building models in Matlab/Simulink toolbox, vehicle ABS-controller is implemented by various control schemes. And it get the several test data obtained under different road conditions. These data are comparaed with the result of non-ABS-test, validating that ABS ensures excellent braking performance and steering characteristic in vehicle braking process. In the end of the article, It demonstrates the design of MSP430based ECU and control program.In the first part of this paper, history of ABS and current situation of worldwide study is introduced, as well as the essential mechanism, modern ABS layout and structure. It illustrates and analyzes some prevailing or promising ABS control schemes, such as PID, fuzzy control, Neuro-fuzzy control, etc.In the second part of paper, some key simulation models are listed as follows. Under the circumstance of Matlab or Simulink, the author establishes ABS validation model and multiple road models, sustained by dynamic analysis. PID control, fuzzy control, Neuro-fuzzy are also built for the purpose of collaborative simulation. These simulations verifies that all the control schemes above could enhance the braking performance and safety of the vehicle under various road condition. Also, by comparison of data and status of control schemes mentioned above, features, merits and drawbacks are given. According to all these characteristics proposed some improvement ideas.In the last part of this article, design procedure of core ECU and correspond circuits is demonstrated, like kernel system, wheel velocity manipulation circuit, etc. Main control program that based on PID control theory is also developed. This part also analyzes basic function unit and its realization, completes the design of ABS ECU system.