Jixie chuandong (Jan 2018)
Improved Dual-tree Complex Wavelet Packet Transform with Application to Fault Diagnosis
Abstract
Aiming at the defects of frequency derangement and overlap in dual-tree complex wavelet packet transform,an improved decomposition algorithm of dual-tree complex wavelet packet transform is proposed. The defect of frequency derangement is eliminated by exchanging the order of sub-nodes originated from high frequency band,and the defect of frequency overlap is overcome by designing the filter of Chebyshev which can eliminate respectively the frequencies outside the pass bands of low frequency and high frequency sub-band. A approach for gearbox fault diagnosis based on the improved dual-tree complex wavelet packet transform and spectral kurtosis is presented,vibration signals of gearbox are decomposed into various frequency band signals,the spectral kurtosis is computed to determine the parameters of band pass filter and got the optimal frequency band. The rotation frequency of fault gear is recognized according to the Hilbert envelope demodulation of the optimal frequency band. The experimental results show that the weak fault feature of gearbox submerged in strong interference can be effectively extracted,and the feasibility and effectiveness of this method are verified.
