• CN: 11-2187/TH
  • ISSN: 0577-6686

›› 2006, Vol. 42 ›› Issue (10): 151-155.

• Article • Previous Articles     Next Articles

OPTIMAL ENVELOPE DEMODULATION METHOD BASED ON ADAPTIVE COMPLEX SHIFTED MORLET WAVELET IN BEARING DIAGNOSIS

LIANG Lin;XU Guanghua   

  1. School of Mechanical Engineering, Xi’an Jiaotong University The State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University
  • Published:2006-10-15

Abstract: Due to the demodulation performance of traditional envelope demodulation methods depend strongly on a number of parameters selected by experience of the user, so an adaptive wavelet-based envelope method derived from complex shifted Morlet wavelet is proposed to overcome this shortcoming. The complex shifted Morlet wavelet family is adopted to extract fault features based on the fact that the bearing defect can excites vibration at specific impact component. Meanwhile, based on the optimal principle of maximal kurtosis of coefficient waveform, the shape parameters of Morlet wavelet, which include center frequency and envelope factor, can be adjusted adaptively to match with the impact component. Thereby, the optimization envelope can be constructed effectively. Experimental results and industrial measurement analysis show that the new approach, compared with the common complex shifted wavelet transform, could effectively extract the weak fault feature with the optimal matching of waveform, and is suitable to extract the incipient fault feature for rolling bearing.

Key words: Complex shifted Morlet wavelet, Continuous wavelet transform, Fault diagnosis, nvelope demodulation

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