本文選題：超聲檢測 + 降噪��； 參考：《中國工程機(jī)械學(xué)報(bào)》2017年04期

【摘要】：針對超聲檢測信號中結(jié)構(gòu)噪聲難以去除的問題,提出了一種變分模態(tài)分解(Variational Mode Decomposition,VMD)和小波能量熵閾值(Wavelet Energy Entropy Threshold,WEET)聯(lián)合降噪的算法.分析了含噪系統(tǒng)熵增的特性以及結(jié)構(gòu)噪聲在不同時(shí)間段的分布特征,提出了用小波能量熵表征信號的含噪狀態(tài),并以小波能量熵最大子區(qū)間的小波系數(shù)參與計(jì)算各個(gè)尺度層的閾值.對仿真及實(shí)測信號進(jìn)行處理,結(jié)果表明,該方法(VMD-WEET)能很好地抑制超聲回波信號中存在的白噪聲及結(jié)構(gòu)噪聲,還原了準(zhǔn)確的波形特征,驗(yàn)證了其有效性.
[Abstract]:In order to solve the problem that structural noise is difficult to be removed in ultrasonic signal detection, a new algorithm for noise reduction is proposed, which is based on variational Mode decomposition (VMD) and wavelet Energy Entropy Energy Entropy decomposition (Wet) combined with wavelet energy entropy threshold. The characteristics of entropy increase in noisy system and the distribution of structural noise in different time periods are analyzed. The wavelet energy entropy is used to characterize the noisy state of the signal. The wavelet coefficients of the maximum sub-interval of wavelet energy entropy are used to calculate the threshold of each scale layer. The simulated and measured signals are processed. The results show that the proposed method can effectively suppress the white noise and structural noise in the ultrasonic echo signal, restore the accurate waveform features, and verify its effectiveness.
【作者單位】： 華北電力大學(xué)能源動力與機(jī)械工程學(xué)院;中國航發(fā)北京航科發(fā)動機(jī)控制系統(tǒng)科技有限公司;
【基金】：中央高�；究蒲袠I(yè)務(wù)費(fèi)資助項(xiàng)目(2014MS118)
【分類號】：TG115.285

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