Research On The Vacuum Auxiliary Braking System Of Automobile

With the rapid development of automobile research and technology, people are more and more high requirement for automobile power performance and comfort at the same time, with continuously increasing concern about the safety of cars. Among them, the braking safety is particularly important, because good braking performance is the basic guarantee of car safety driving. At present, the commonly used automobile braking is to install a mechanical friction brake on the wheel, But frequent braking for a long time can make the brake drum(disc) and friction lining(brake lining) overheat, which can increase the wear of the friction and shorten its service life. Many advanced electronic control braking system are used, such as anti-lock braking system(ABS), electronic braking system(EBS) and acceleration slip regulation(ASR), which greatly improve the reliability of the friction braking system within the effective range, but are not much helpful for the temperature and wear of the brake. To solve these problems, a feasible solution is to install the auxiliary braking device. A new auxiliary braking system is studied in this paper, which is used to shorten the braking distance of the automobile in the case of emergency braking by using the principle of vacuum adsorption technology. The main work of this thesis is as follows:First, through the analysis and study of a large number of real vehicle braking condition data(including the opening of the brake pedal, the brake pedal opening rate, brake pedal force, braking deceleration), the braking intentions are classified and characterized.Second, identifying the driver’s braking intention by using Matlab to build the fuzzy identification model.Third, the Simulink simulation model is set up by using established fuzzy identifier. By collecting the real automobile braking data, offline verification is carried out for the identify effect of fuzzy identifier.Fourth, the Simulink simulation programs of the the established driver’s braking intention identification model automatically generate C language code which is suitable for Freescale microcontroller of vacuum auxiliary braking system controller.Fifth, the structure of vacuum auxiliary braking system is improved to reduce the leakage rate, leakage time and increase its vacuum degree, so as to improve the fit degree of the braking sucker and the ground, and increase the friction force between the rubber of brake sucker with the ground in the opposite direction of automobile which can provide sufficient auxiliary braking force for the automobile.