Abstract: Fast
wavelet multi-resolution analysis (wavelet MRA) provides a
effective tool for analyzing and canceling disturbing components
in original signal. Because of its exponential frequency axis,
the method isn't suitable for extracting harmonic components.
The modified exponential time-frequency distribution (MED) overcomes
the problems of Wigner distribution (WD), can suppress cross-terms
and cancel noise further more. MED provides high resolution in
both time and frequency domains, so it can make out weak period
impulse components from signal with mighty harmonic components.
According to the "time" behavior, together with "frequency" behavior
in one figure, the essential structure of a signal is revealed
clearly. According to the analysis of algorithm and fault
diagnosis example, the joint of wavelet MRA and MED is a
powerful tool for fault diagnosis.
Key words: Wavelet multi-resolution analysis Denoising Modified exponential distribution Fault diagnosis
Manuscript received on
June 27, 2000; revised manuscript November 20, 2000
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