An effective centre frequency selection scheme based on variational mode extraction and its application to gear fault diagnosis

Abstract

The penalty factors and number of modes in variational mode decomposition (VMD) have to be set empirically. In addition, it is a challenge to select the most useful mode from the multiple mode components decomposed using this method. To solve these problems, an effective gear fault diagnosis method using variational mode extraction (VME) and envelope analysis is proposed. Due to the blindness in determining the centre frequency of the desired mode, this study proposes a method to select the centre frequency based on the maximum signal-to-noise index among the meshing frequency and its harmonics. The desired mode obtained according to the selected centre frequency has the maximum signal energy and relatively minimum noise energy. Two case studies verify that the presented approach is effective for gear fault feature extraction. Comparisons with VMD and empirical mode decomposition (EMD) further highlight the superiority of the method.