“…This algorithm is superior to the traditional VMD method and further extends the application of VMD for compound fault diagnosis. Many scholars have also applied neural networks for fault diagnosis [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ], and the improved algorithms have shown good results. In addition, there are also many decomposition methods based on signal processing, including local mean decomposition [ 36 , 37 , 38 , 39 , 40 ], Fourier decomposition [ 41 ], and other methods, which are widely used in gearbox fault diagnosis.…”