Feature extraction of bearing outer ring fault for encoder installation error suppression
To address the problem that the installation error in the encoder signal makes it difficult to extract the bearing outer race fault features,an error suppression scheme for encoder installation was proposed.According to the method,the envelope on the original instantaneous angular speed signal was obtained based on the encoder mounting error characteristics combined with the root mean square envelope technique.The encoder installation error components were further fitted based on the segmented stepwise approximation technique and the absolute mean difference index combined with the inverse slope correction method.The optimized envelope window length was determined adaptively by improving the energy ratio index,and the corresponding residual signal was obtained.Through the envelope spectrum of the residual signal,the fault characteristics order of the bearing outer race was obtained and the fault characteristics were revealed.Compared with the traditional cepstral pre-whitening method which suppressed periodic components,the first 3 fault characteristic orders of the outer ring of rolling bearing were clearly extracted by this method,proving that the proposed method has better suppression effect on encoder error.The effectiveness of the proposed scheme was verified by simulation and experiment.
instantaneous angular speedencoder installation errorroot mean square envelope techniquerolling element bearingfault diagnosis
NETL
NSTL
万方数据
