基于Wigner-Ville分布与小波尺度谱融合的时频特征提取方法  

Time-frequency feature extraction based on fusion of Wigner-Ville distribution and wavelet scalogram

作　　者：龚海健[1] 黄伟国[1] 赵凯[1] 李双[1] 朱忠奎[1] 

机构地区：[1]苏州大学城市轨道交通学院,苏州215021

出　　处：《振动与冲击》2011年第12期35-38,共4页Journal of Vibration and Shock

基　　金：国家自然科学基金资助项目(50905121);江苏省自然科学基金资助项目(BK2010225)

摘　　要：时频分布提供了信号特征在时间域和频率域的联合分部信息。作为两种典型的时频分布表示方法,Wigner-Ville分布(WVD)和尺度谱都存在的缺陷,体现在WVD存在严重的交叉项,尺度谱时频聚集性差。在WVD和尺度谱的基础上提出一种以消除交叉项和保持高分辨率为目的的时频特征融合算法。仿真分析验证了该算法能够有效抑制交叉项,可以很好地保持时频分辨率,且抑制了弱噪声对于时频特征的干扰。通过仿真信号的分析将该算法与Cohen类时频分析方法进行比较,验证了其在时频特征表示方面的优越性。将时频融合算法应用于轴承振动信号的时频表示,结果表明该方法能基本消除时频特征表示中的交叉项且保持了较高的时频分辨率,验证了算法在信号特征表示方面的有效性。Time-frequency distribution provides signal joint features in time and frequency domains. Wigner-Ville distribution （WVD） and wavelet scalogram, as two methods of time-frequency analysis, both have inherent defects, because Wigner-Ville distribution suffers from severe interference terms, while wavelet scalogram has low time-frequency concentration. A time-frequency fusion algorithm based on Wigner-Ville distribution and wavelet scalogram was proposed here aiming at eliminating interference terms and keeping good resolution. Simulation study showed that the time- frequency fusion algorithm is effective in suppressing the interference terms while it keeps high resolution in time and frequency plane, and it also inhibits the disturbance of weak noise. The comparison of the proposed method with Cohen＇s idea of time-frequency analysis reveals that the fusion algorithm is superior. Applied in time-frequency representation of bearing vibration signals, the fusion algorithm eliminated interference terms of time-frequency feature representation and kept good time-frequency aggregation, it was shown that the proposed fusion algorithm is effective in time-frequency feature extraction.

关 键 词：WVD 尺度谱 交叉项 分辨率 融合 

分 类 号：TN911.7[电子电信—通信与信息系统]