蔡新举,黄盛霖,李 政,林 愈

摘 要:某电源信号是典型的非平稳、非线性信号,信号中带有各种噪声,需进行适当处理。小波变换时的频局域性好,是分析非平稳信号的有效工具之一。研究基于小波变换的阈值消噪法,借助LabVIEW平台,通过仿真试验,对软阈值和硬阈值消噪及采用不同的小波函数消噪进行了分析。应用LabVIEW对电源信号进行采集,并且对LabVIEW中调用Matlab里的小波函数进行去噪分析的程序进行研究,收到良好的效果,为进一步提高电源信号消噪处理的效果奠定了基础。

关键词:LabVIEW;小波变换;Matlab;阈值消噪

中图分类号:TN927文献标识码:A

文章编号:1004-373X(2009)20-175-03

Power Signal De-noising Based on Wavelet Analysis

CAI Xinju,HUANG Shenglin,LI Zheng,LIN Yu

(Naval Aeronautical and Astronautical University,Yantai,264001,China)

Abstract:Power signal of some equipment is typically non-stationary and nonlinear,inevitably,there are kinds of yawp which need being disposed.The time frequency character of wavelet transform is perfect,and it is an effective tool of analyzing non-stationary signal.Threshold de-noising based on wavelet transform is introduced,in virtue of LabVIEW plate,by simulating test,soft threshold de-noising is compared to hard threshold de-noising,and different wavelet function are selected for de-noising,the validity of threshold de-noising based on wavelet transform is proved in the process of power signal de-noising.The electrical power signal by data acquisition card in the LabVIEW developing environment,the wavelet function in Matlab is called to make the study of de-noising analysis.The signal de-noising process and testing platform based on wavelet analysis theory and virtual equipment is completed.This study idea could found the base of pushing the de-noising process effect of all kinds of signal.

Keywords:LabVIEW;wavelet transform;Matlab;threshold de-noising

0 引 言

在现代装备中,电源如同血液在人体中的作用,是整个装备的动力来源,高精度电源信号的需求对电源信号的消噪处理提出了更高要求。为了减少噪声的影响,需要对采集到的信号进行消噪处理。传统的消噪方法是基于傅里叶变换理论的“滤波”法,这种方法存在着保护信号局部性和抑制噪声之间的矛盾,实际的处理效果不够理想。

小波分析是近20年来逐步发展起来的数学分支,目前应用于信号处理、图像处理、语音处理、机械故障诊断、地震波分析等众多领域中。由于小波变换具有良好的时频局部化性质,且小波函数的取法是不惟一的[1]。因此,小波分析在信号的消噪中得到了广泛的应用,小波阈值法就是其中的一种。

LabVIEW(Laboratory Virtual Instrument Engineering Work bench)是由美国NI 公司(National Instruments)推出的一个功能强大而又灵活的仪器和分析软件,是一种崭新的图形化编程语言(G语言)和开发环境,其源程序完全是图形化的框图,避免了传统语言线性结构的困扰。……