Incipient fault feature extraction using lifting scheme packet

To identify incipient fault feature of gearbox weak signal, a new method to design lifting scheme packet is developed. This method is based on lifting scheme, the decomposition procedure and reconstruction procedure algorithms of lifting scheme packet are constructed, and the signal at each frequency band is reconstructed to identify incipient fault feature in time domain. The lifting scheme packet operators which lock on the local statistics of decomposition signal are calculated. Both lifting scheme packet and traditional wavelet packet are applied to analyze the rub fault vibration signal of a gearbox, lifting scheme packet desirably identifies demodulation waveform and periodic impulses, and the results confirm that lifting scheme packet outperforms traditional wavelet packet method.