【摘要】：針對(duì)雙激光位移傳感器測(cè)量大型殼段厚度過程中噪聲對(duì)檢測(cè)精度的影響,提出利用變分模態(tài)分解來實(shí)現(xiàn)對(duì)厚度信號(hào)的自適應(yīng)去噪,利用相鄰固有模態(tài)函數(shù)之間的離散Hellinger距離來獲取最佳的模態(tài)數(shù)。該方法將變分模態(tài)分解算法引入到激光信號(hào)的自適應(yīng)濾波過程中,分析并改進(jìn)了變分模態(tài)分解算法的過分解、欠分解以及能量泄露的問題。然后,對(duì)改進(jìn)的變分模態(tài)分解與希伯特振動(dòng)分解和自適應(yīng)噪聲總體集合經(jīng)驗(yàn)?zāi)B(tài)分解進(jìn)行性能對(duì)比,提出了固有模態(tài)函數(shù)的相對(duì)瞬時(shí)能量概率的概念。最后,結(jié)合離散Hellinger概率分布距離理論判斷固有模態(tài)之間的信噪分界點(diǎn),實(shí)現(xiàn)了對(duì)信號(hào)的重構(gòu)及濾波處理。仿真和實(shí)驗(yàn)結(jié)果表明,該方法對(duì)殼段厚度信號(hào)處理的信噪比為39.27dB,比自適應(yīng)噪聲總體集合經(jīng)驗(yàn)?zāi)B(tài)分解方法提高了10dB,具有良好的自適應(yīng)性,無需先驗(yàn)條件便能快速有效地識(shí)別并分離激光信號(hào)中的噪聲成分。
[Abstract]:In view of the effect of noise on the detection accuracy in the process of measuring the thickness of a large shell with a double laser displacement sensor, a variational mode decomposition (VMD) is proposed to realize the adaptive de-noising of the thickness signal. The optimal modal number is obtained by using the discrete Hellinger distance between adjacent inherent modal functions. In this method, the variational mode decomposition algorithm is introduced into the adaptive filtering process of laser signal, and the overdecomposition, underdecomposition and energy leakage of the variational mode decomposition algorithm are analyzed and improved. Then, the concept of relative instantaneous energy probability of inherent mode function is proposed by comparing the performance of improved variational mode decomposition with Hilbert vibration decomposition and adaptive noise set empirical mode decomposition. Finally, combining the discrete Hellinger probability distribution distance theory to judge the signal-noise boundary point between the natural modes, the signal reconstruction and filter processing are realized. The simulation and experimental results show that the SNR of this method is 39.27 dB for the shell thickness signal processing, which is 10 dB higher than the adaptive noise set empirical mode decomposition method. The noise components in laser signals can be quickly and effectively identified and separated without prior conditions.
【作者單位】： 哈爾濱工業(yè)大學(xué)電氣及自動(dòng)化學(xué)院;
【基金】：國家自然科學(xué)基金資助項(xiàng)目(No.61108073) 上海航天科技創(chuàng)新項(xiàng)目(No.SAST2015029)
【分類號(hào)】：TN249;V475.1
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本文編號(hào)：2276743