摘要
根据小波域阈值滤波的降噪特性,把改进的阈值函数方法和平移不变小波变换相结合,提出一种改进阈值法的小波去噪方法。所提方法和包络分析相结合,能够较好地解决由于随机噪声干扰而造成提取的包络信号轮廓信息粗糙的问题,改善包络提取精度。实现方法是先将改进阈值法的小波去噪方法作为包络分析的前置处理手段,再对信号进行包络提取和包络细化谱分析,获得突变特征频率。仿真结果表明,该方法可以有效的抑制噪声,能够较准确地提取信号包络和突变特征频率。
According to the noise reduction feature of wavelet threshold filtering,improved threshold function method and translation invariance wavelet transform were combined.So a wavelet denoising method of improved threshold was used.The combination of proposed method and envelopment analysis,could be better able to solve the problem of extracting the envelope signal that has rough outline caused by random noise interference,and could improve the accuracy of envelope extraction.The implementation was that,first,the wavelet de-noising method of improved threshold was used as pre-processing means of envelopment analysis.Then,the signal envelope was extracted and the envelope spectrum was refined,in order to obtain mutation characteristic frequency.Experimental results show that this method can suppress noise effective,and more accurately extract the signal envelope and the mutation characteristic frequency.
出处
《电力科学与工程》
2010年第6期6-10,43,共6页
Electric Power Science and Engineering
关键词
小波变换
阈值去噪
包络分析
包络提取
细化谱分析
wavelet
threshold denoising
envelopment analysis
envelope extraction
refine spectrum analysis
