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| DE-NOISING METHOD OF LARGE ROTATING MECHANICAL NON- STATIONARY VIBRATION SIGNAL BASED ON ENSEMBLE EMPIRICAL MODE DECOMPOSITION |
| CAO Chongfeng YANG Shixi YANG Jiangxin |
| College of Mechanical and Energy Engineering, Zhejiang University,Hangzhou,310027,China |
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Abstract Focusing on the defects of different de-noising methods in processing non-stationary vibration signal, a method based on Gausses white noise assisted empirical mode decomposition (EMD) technique which adaptively eliminates noise involved rotating machine non- non-stationary vibration signal is presented. This method is an ensembled algorithm of EMD de-noising method, which applies dyadic scales decomposition characteristics of normal distribution white noise with EMD, could effectively suppress mode mixing that occurred in analyzing non-stationary vibration signal with EMD de-noising method and obtain higher signal-to-noise ratio(SNR). Simulation numerical signal and experimental signal of rotor running state are used to test and compare the performances of the method and EMD based de-noising method and wavelet de-noising method. The results show that the EEMD based noise cancellation method presented in the paper has more effective de-noising performance, not only eliminates random noise, but suppresses intensity noise and extracts vibration intrinsic modes that reflect real physical meaning of signal.
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Received: 20 October 2008
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Corresponding Authors:
CAO Chongfeng
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2009, Vol. 28 
