Fault Diagnosis of Rolling Bearings Based on High-order Transient-extraction Transform
The traditional time-frequency analysis method obtains the instantaneous frequency characteristics of non-stationary signals by constructing the time-frequency model of signals.However,due to the discontinuity of short-time tran-sient signals in time domain and the limitation of Heisenberg uncertainty principle,it is impossible to provide accurate time information for the short-time transient signals.In this work,aiming at the extraction of transient fault signals in rotating ma-chinery,a high-order transient extracting transform (HTET) was proposed.In this method,Taylor expansion was used to esti-mate the high-order group delay operator,which was used to replace the key parameters in the low-order time-frequency method.Through obtaining a more concentrated time-frequency representation,the accurate location of the impact character-istics formed in mechanical faults was determined.In addition,the impact component in the signal could be effectively ex-tracted and the interference of background noise was removed.Simulation analysis verified the performance of the proposed method in time-frequency feature characterization and noise suppression.The experimental analysis verified that the pro-posed method can be used for bearing fault diagnosis of artificial defects and naturally formed defects,which has practical significance for the expansion of signal processing theory and mechanical fault diagnosis.