Model-based Fault Prediction And Simulation For ABS/ASR System

The ABS (Anti-lock Braking System) is an important safety device in modern vehicles. TheABS improves the performance of braking stability and braking distances of vehicles. The ASR(Acceleration Slip Regulation) is the force control system for getting the optimal driving force atthe starting acceleration period of vechile. The ASR prevents the driving force from exceedingthe adhesion force of tire and road surface, which could cause the wheel slippage.The capabilities of ABS/ASR system affects the safety performance of vehicles directly. Inorder to guarantee the reliability and speedy maintenance, it is important to improve the faultdiagnosis capability of the ABS/ASR system. This paper presents a Matlab/Simulinkmodel-based method of automobile ABS/ASR system for fault diagnosis simulation.Firstly, this paper presents the ABS/ASR system control strategy and simulation models.Secondly the theoretical formulas and Simulink models of all the increasing, holding anddecreasing periods of the ABS/ASR system hydraulic adjustment device are carrid out. Thirdly,the failures such as hydraulic oil leak, valve clamping and piston pump performance failures aregoing to be joined in the the typical ABS/ASR hydraulic system. And then, ABS/ASR hydraulicsystem’s Simulink model and simulation analysis are focused on. Finally, it is easy to obtain thefailure simulation graph by the above simulation diagram characteristics of the ABS/ASRhydraulic system.Afterwards, two classic faults in the wheel speed sensors, which are lost tooth and too muchgap between the sensor head and the gear ring, are analysised. The results of the signalcharacteristics of these failures’ occurrence are found. Finally, the dSPACE ControlDesksoftware raising with Simulink model is intoduced in this thesis, espcially the benefits ofintuitive and convenience. This thesis paves the way for future hardware-in-the-loop simulation.