Novel Technology for Bearing Condition Monitoring Based on the Bicoherence

摘要

Bearing defect diagnosis is traditionally done using the demodulation/enveloping technology. Diagnosis is mostly based on the spectrum of the squared envelope signal. Use of the higher order spectra (HOS) shown to have a tremendous diagnostic potential for vibration diagnosis. However, application of the HOS for bearing diagnosis is very limited. In this paper we implemented and experimentally validated a novel higher order spectra based on the envelope analysis for diagnosis of ball bearing defects at early stage of bearing damage defects. The implemented technology employs the spectral kurtosis to obtain a frequency band for the demodulation and the third order normalized spectra, i.e. the bicoherence for diagnosis of bearing fault. The high effectiveness of the diagnostics of the implemented technology has been experimentally revealed and compared with that of well-known demodulation/enveloping technology.