Research On The Detection Method Of The Vehicle Hub Bearing Unit And System Development Based On Danger Theory

The hub bearing unit is one kind of rolling bearing. It is one of important parts ofbearing and power transmission in a vehicle. So, its life and performance is directlyrelated to the safety, stability and comfort of a vehicle. Along with the integration andcomplexity of vehicle hub bearing unit, the fault behavior of bearing shows thecharacteristic of correlation, complexity, uncertainty and etc. Thus, the noise andvibration signals of a vehicle hub bearing unit show the intensive feature of nonlinear,which makes it be more difficult to detect its fault diagnosis. According to somecorrelative studies, the domestic vehicle hub bearing manufacturers lack thecorresponding technology for performance test. Thus, it is good for theorydevelopment and real engineering practice to do research on the detection method of avehicle hub bearing unit and system development.In this paper, we first review the researches on the detection system andperformance test technology of a vehicle hub bearing unit in domestic and overseas.Then, some current main intelligent fault detection methods for mechanical systemare analyzed, and their advantages and disadvantages are summarized.Then, according to the biological immune mechanism, we studied themainstream theory in artificial immune system in order to solve the problem in faultdetection effectively, improve the accuracy, intelligentization and practicability ofdetection. The problem of the self-nonself theory is analyzed and the fundamental ofDanger Theory is extensively introduced. Afterwards, based on the wavelet packettechnology, a fault diagnosis approach to vehicle hub bearing unit based on DangerTheory is proposed. During the new approach, the definition of status feature vectorof a hub bearing unit, antigen, antibody and calculation of affinity are given; thedanger zone is constructed; three kinds of signals in the Danger Theory are defined.This approach has a higher fault detection rate and lower misjudge rate. Thestimulation shows the effectiveness of the proposed approach.Besides the theoretical research, this paper also addresses the development of testsoftware and test bench. The fault diagnosis system software for vehicle hub bearingunit is designed by Visual Basic. Then, the test bench for vehicle hub bearing unit isdesigned. The test about temperature rise, grease leakage, anti saline mud can beaccomplished using the designed test bench in this paper at lower cost and higher efficiency.Finally, the actual data got from testing site is used to verify the certainapplication value of the proposed approach.