摘要
小波分析作为一种优秀的时频分析方法,越来越多地应用于信号、图形处理以及故障诊断等领域。在噪声处理领域,基于小波变换的阈值函数较多,但效果不一。基于二进小波变换,在Sigmoid函数基础上,建立介于软硬阈值函数之间新的阈值函数,即通过改变新阈值函数中不同的参数,能够不同程度地逼近软硬阈值函数。从应用不同阈值函数对六种噪声信号滤波效果分析可知,采用改进的阈值函数能够使滤波后的信号在提高信噪比的同时,更接近于真实信号。
Wavelet analysis, as one of the advanced time-frequency analysis methods, has been widely used in signal and figure processing, damage detection and so on. Many threshold functions have been proposed based on wavelet transformation in noise processing, but their filtering efficiencies are quite different. In this paper, based on binary wavelet transformation and Sigmoid function, a new threshold function between soft and hard threshold functions was built. By adjusting different parameters of this function, the soft or hard threshold functions could asymptotically approached. According to the results of filtering of six different signals using different thresholds, it can be concluded that the new threshold function can raise the signal-to-noise ratio, and make the filtered signal closer to the true signal.
出处
《噪声与振动控制》
CSCD
2013年第2期117-122,127,共7页
Noise and Vibration Control
作者简介
赵晓燕（1980-），女，山东德州人，工学博士，目前从事结构健康监测及检测研究。E—mail：zhaoxiaoyan2002@yahoo．com．cn
