Human auditory system possesses a desirable capacity for analyzing, processing and identifying signals. Whereas different types of rolling bearing faults cause different vibration noises, a new method based on early auditory model (EA model) is proposed for the diagnosis of rolling bearing faults. Firstly, according to characteristics of mechanical vibration signal, the EA model was established by simulating the human auditory system. Secondly, sample signals were processed by the EA model to build sets of auditory spectrums, the characteristics of which were extracted with the purpose of obtaining the characteristic auditory spectrums that reflected the overall characteristics of failure states, so as to further simplify the data. At last, based on spectral correlation, it applied integrated correlation coefficient to identify fault type. Experimental results show that the method is capable of extracting and distinguishing the overall characteristics of 12 types of rolling bearing fault states (four different degrees of faults and normal state of inner race, outer race and rolling element) with almost 100 percent accuracy possesses considerable feasibility and certain potentialities in practical application.
IntroductionRolling bearings are widely used in rotating machineries, so that their states directly affect the performance of machinery equipment. In order to reduce the accidents of rotating machinery, it is necessary to realize accurate diagnosis of rolling bearing faults. At present, there are three types of characteristic extraction methods for rolling bearing faults i.e. spectrum analysis method, envelope analysis method and shock pulse method [1][2][3][4].At the work site, when different types of rolling bearings faults occur, it will produce different sounds during the process of rotating. As a result of that vibration signals and noise signals are homologous, it is able to conduct characteristic extraction and fault identification to vibration signals of bearings through the processing mechanism of human auditory system. With respect to auditory system simulation, the current auditory model in the field of auditory periphery system simulation is already mature, and its performance is comparatively close to biological experiments [5].In consideration of advantages of auditory model and the conditions of diagnosis of rolling bearing faults, this paper will introduce EA model into diagnosis of rolling bearing faults, and also design the method of fault characteristics extraction and identification in line with multiple auditory spectrum. By utilizing the data validation for bearing vibration provided by the American Case Western Reserve University, it indicates that the proposed method possesses relatively high accuracy in diagnosis of roller bearing faults.
METHOD OVERVIEWImplementation process of the proposed method is shown in Figure 1.