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Abstract: A
methodology for the design of a general comb filter is proposed, and it
is demonstrated that the traditional time domain averaging is just a
special case of the general comb filtering. On this basis, a novel
signal analysis technique capable of extracting the periodic waveform
with inexactly known period from noisy discrete-time observations is
presented. Firstly the region that the signal fundamental frequency may
lie in is finely discretized, resulting in an array of candidates of the
fundamental frequency estimate. Then the contaminated signal is
independently cleaned by an array of comb filters, each with a candidate
of the fundamental frequency estimate as the reference frequency.
Finally the obtained series of filtered signals are depicted as a gray
image, and the interested waveforms are picked up for further analysis.
The validity of the approach is confirmed by analyzing the synthetic
signal and the vibration signal produced by multiple point defects in a
rolling element bearing.
Key
words: Signal
processing Comb filter Array Periodic waveform Fault diagnosis
CLC No: TN911.72
TP206
国家自然科学基金(50475022)、国家973重点基础研究计划(2005CB724103)和上海市青年科技启明星计划(04QMX1415)资助项目. Received 20050528,
received in revised form 20051225
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