Research On Vehicle Fault Diagnose Based On Vibration Signal Analyzing Technique

Automobile abnormal vibration fault detection and diagnosis is inevitable in using a vehicle. Nowadays customers expect to have a car with higher standards both in riding comfort and reliability. With more and more complex structures and precision parts adopted in designing and manufacturing a car, abnormal vibration fault detection and diagnosis is becoming more and more difficult. In the paper, analysis on motor, power shaft and wheels has been completed in order to find the reason of abnormal vibration on a coach. During the analysis, two methods have been employed:traditional abnormal vibration diagnosis method and vibration&noise analysis method. Based on these methods, a software tool has been programmed in solving this kind of problem which may provide a choice of their work for maintenance man.Firstly, by analyzing the abnormal vibration source and vibration characters of the motor, power shaft and wheels, a mathematic model of rotate speed-frequency was been built. Secondly, by comparing FE calculation results and modal experiment outcome, modal parameters were obtained. Thirdly, writing software to diagnosis abnormal vibration via MATLAB GUI which could calculate rotate speed-frequency information for different parts if structure and motor parameters were given to the software. Lastly, find out the abnormal vibration source with experiment following guidelines of the traditional method. With the help of the software, by comparing the modal results and experiment outcome, an improvement project was proposed.