“…Short-time Fourier transform (STFT) method (Khodja, Aimer, Boudinar, Benouzza, & Bendiabdellah, 2019;Li, Zhang, Qin, & Sun, 2018) is limited by the window function and has no universality. Wavelet transform method (Guo & Xiao, 2017; CONTACT Jie Ma mjbeijing@163.com Ma, Zhang, Fan, & Wang, 2019;Xu, Tian, Zhang, & Ma, 2019) needs to select an appropriate wavelet base for the fault diagnosis of rolling bearing, and the parameters are pre-set by prior knowledge, where the quality of the parameter selection often has a great impact on the results. The Mahalanobis distance is based on the distribution of features throughout the space as a basis for discrimination, but the sample classification effect is not good under strong noise (Ji, Huang, & Zhou, 2019).…”