一种适用于泄流结构振动分析的信号降噪方法

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振动与冲击 ›› 2015, Vol. 34 ›› Issue (20) : 179-184.

论文

张建伟，江琦，赵瑜，朱良欢，郭佳

作者信息 +

A de-noising method for vibration signal of flood discharge structure

ZHANG Jian-wei，JIANG Qi，ZHAO Yu，ZHU Liang-huan，GUO Jia

Author information +

文章历史 +

摘要

针对低信噪比泄流结构振动信号有效信息难以提取问题，提出将小波阈值与经验模态分解(EMD)联合的信号降噪方法。利用小波阈值滤除大部分高频白噪声，降低EMD端点效应；进行EMD分解获得具有相对真实物理意义的固态模量(IMF)；通过频谱分析重构特征信息IMF获得降噪信号。构造仿真信号，将该方法与数字滤波、小波分析及EMD降噪效果进行对比。结果表明，该方法能精确滤除泄流结构的振动噪声保留信号特征信息，滤波降噪较优越。将其用于拉西瓦拱坝水弹性模型，精确分析坝体结构振动优势频率，为坝体结构的安全运行与在线监测提供基础，亦为大型泄流结构在强背景噪声下的结构有效信息提取提供捷径。

Abstract

In view of the problem that useful characteristics of flood discharge structure vibration signal with low signal to noise ratio which extracted difficultly, a novel de-noising method, which combines wavelet threshold and empirical mode decomposition (EMD), was proposed. Firstly a part of white noises were filtered out with wavelet threshold method, which can reduce the endpoint effect of EMD; then decomposing the signal with EMD, obtained a series of intrinsic mode functions (IMF) which contains real physical meaning; finally reconstructed the IMF of characteristic information to achieve the de-noised signal through spectrum analysis. Constructing the simulation signal, and comparing the filtering effect of this method with digital filter, wavelet threshold and EMD, study shows that, it is a superior de-noising method, which can filter the vibration noise of flood discharge structure accurately and retain the characteristic information. It is used in Laxiwa arch dam hydro-elastic model, analyzing the dominate frequency of dam structure precisely, which can provide the basis for safe operation and on-line monitoring of the dam structure. This proposed method can effectively solve the problem of structure information extraction for large flood discharge structure under the background with strong noise.

导出引用

张建伟，江琦，赵瑜，朱良欢，郭佳. 一种适用于泄流结构振动分析的信号降噪方法[J]. 振动与冲击, 2015, 34(20): 179-184

ZHANG Jian-wei，JIANG Qi，ZHAO Yu，ZHU Liang-huan，GUO Jia. A de-noising method for vibration signal of flood discharge structure[J]. Journal of Vibration and Shock, 2015, 34(20): 179-184

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