Optical Encoder-Based Feature Extract of Faulty Rolling Element Bearing Under Variable-Speed Conditions

Optical encoder-based condition monitoring of the rolling element bearing (REB) is becoming a hot topic, in which the suppression of interference components is essential for the REB fault feature extraction under variable-speed conditions, such as encoder installation error, speed fluctuation components, encoder etching, etc. To address this issue, the features of the interference components in instantaneous angular speed (IAS) signal are discussed in this study. Then, a parametric decomposition structure (PDS) is proposed to decompose parameters adaptively, which has the advantages of low-computational cost and high precision. Besides, to evaluate the richness of the faulty REB, an evaluation indicator is studied. At last, an adaptively Savitzky-Golay (SG) filter is proposed to extract fault features related to the faulty REB. Simulation and experiment results show that the proposed scheme can be used to enhance the features related to the REB, and the angular synchronous averaging and the angular cyclostationary are used to verify the particularity of the IAS signal under variable speed conditions.