Method Of Wear Life Prediction And Failure Warning For Automobile Brake Pad

Brake pad is an important part of automobile brake pair.Due to brake friction and the friction heat generated,surface materials will be continuously consumed and brake pad will wear out gradually.When the brake pad is overworn,it will affect the braking performance,which is very unfavorable for driving safety.Premature maintenance and replacement result in the waste of resources.Therefore,it is necessary to carry out wear life prediction and failure warning for automobile brake pad based on its wear law,which can not only effectively prevent braking accidents,but also give full play to the working life of brake pad.It will provide great theoretical value and practical significance for instructing the maintenance and replacement and improving operational reliability of brakes.In this thesis,automotive brake pad was selected as the research object.Wear test under different braking conditions was carried out.Influence laws of brake conditions on the wear performance of brake pad were explored,and wear loss prediction based on wear laws was studied,and then method of wear life prediction and failure warning for brake pad was investigated.Firstly,mechanical hardware,and measurement and control system of brake simulation test bench were designed and built.Meanwhile,wear loss measurement method of automobile brake pad and brake simulation wear test plan were designed.Secondly,wear test of brake pad under different braking conditions was carried out,and the change laws of brake pad wear under different initial braking speed and braking pressure were mainly studied and analyzed.It was found that wear loss rises slightly but does not change significantly with the increase of brake pressure.With the increase of the initial brake speed,the frequency and duration of the friction between brake pair will increase,and wear loss will increase significantly,especially when the initial braking speed is large.The wear law of brake pad at different frictional surface temperatures was studied by changing the braking interval time.It was found that wear loss was more affected by the combined effects of other braking conditions parameters,such as the initial braking speed,than frictional surface temperature alone.Accordingly,the initial weights and thresholds of BP neural network were optimized by genetic algorithm.The wear loss prediction model of brake pad based on braking conditions was constructed using the test data as a sample.Simulation results showed that GA-BP neural network optimized by genetic algorithm had faster convergence speed and prediction accuracy than BP neural network.Furthermore,verification test of wear loss prediction of brake pad was conducted,and results showed that wear loss prediction model established by GA-BP neural network could basically realize the accurate prediction of brake pad wear under different braking conditions.Finally,the significance of predicting the dynamic life of brake pad was put forward.Based on the established wear loss prediction model,wear life of brake pad under a typical braking condition was used as an example to illustrate the application of the wear loss prediction model in the wear life prediction.Furthermore,online learning model of mileage and wear loss was discussed,and the monitoring and selection methods of mileage and braking conditions parameters were analyzed.And overall structure of wear life prediction and failure warning system of automobile brake pad was designed.