Generalized S transform and its application in mechanical fault diagnosis

The generalized S transform (GST), which inherits the idea of multi-resolution analysis from wavelet transform, is a lossless and linear transform, its time-frequency resolution is concerned with the frequency of signal. Based on these excellent features of GST, here, the GST is introduced into the mechanical fault diagnosis. A new fault diagnosis method based on the generalized S transform is proposed. The proposed method is compared with the other time-frequency analysis method, such as short time Fourier transform, wavelet transform and standard S transform. The simulation results show that the proposed method has obvious advantage. GST has a higher time-frequency resolution than the other time-frequency analysis, and can clearly reflect the characteristic frequency of mechanical fault. Finally, the proposed method has been successfully applied to the fault identification of rolling bearing and rub-impact fault with different degree of severity. The experiment results show that the proposed method is very effective. This method can accurately reveal the frequent structure of the rolling bearing fault, and discern rub-impact fault with the different degree of severity. The proposed method provides a new fault recognition method for the fault diagnosis of rolling bearing and rub-impact fault with the different degree of severity.