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Shao Junpeng
Jia Huijuan
Department of Mechanical Engineering,
Harbin University of Science
and Technology,
Harbin 150080, China |
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FEATURE EXTRACTION OF
VIBRATION SIGNALS BASED ON
WAVELET PACKET TRANSFORM
Abstract: A method is proposed for the analysis of vibration signals from components of rotating machines, based on the wavelet packet transformation (WPT) and the underlying physical concepts of modulation mechanism. The method provides a finer analysis and better time-frequency localization capabilities than any other analysis methods. Both details and approximations are split into finer components and result in better-localized frequency ranges corresponding to each node of a wavelet packet tree. For the purpose of feature extraction, a hard threshold is given and the energy of the coefficients above the threshold is used, as a criterion for the selection of the best vector. The feature extraction of a vibration signal is accomplished by computing the reconstruction signal and its spectrum. When applied to a rolling bear vibration signal feature extraction, the proposed method can lead to be very effective.
Key words:
Wavelet packet transform Feature extraction Vibration signal |