Encoder signal-based optimized Savitzky-Golay and adaptive spectrum editing for feature extraction of rolling element bearing under low-speed and variable-speed conditions.

Feature extraction of rolling element bearings (REB) under variable-speed conditions is always one of the hot and difficult points in the field of fault diagnosis. Based on the encoder signal with the advantages of low noise, and direct correlation with machine dynamics, an optimized Savitzky-Golay and adaptive spectrum editing are proposed for REB feature extraction under low-speed and variable-speed conditions. Firstly, the estimated features of the instantaneous angular speed (IAS) and interference components are studied. Secondly, based on the proposed multipoint mean ratio indicator and parametric decomposition structure, an adaptive SG filter is proposed to remove the speed trend component. Thirdly, an adaptive spectrum editing scheme with no transition band and low computational cost advantages is proposed to detect REB fault based on the combination of the cyclic dislocation scheme, the Gaussian function and the Pearson theory. Simulation and experiments are used to verify the effectiveness of the proposed scheme.