摘要
针对基于小波尺度谱的模极大值法提取小波脊线存在受噪声干扰影响大、高频部分频率分辨率低等缺点,提出一种基于最优重分配小波尺度谱的小波脊线提取方法。首先,优化M orlet母小波使其与信号特征成分实现最佳匹配,再对小波尺度谱进行重分配,提高尺度谱的时频聚集性;然后,对重分配尺度谱进行信号奇异值分解降噪,降低噪声干扰影响;最后,利用模极大值法提取出小波脊线,根据小波脊线与频率的关系得到信号的瞬时频率。仿真算例和实际工程应用结果表明,该方法能有效提取出强噪背景下的机械故障特征。
In order to improve the precision of wavelet ridge extracted by modulus maximum method based on scalogram,a new method for extracting wavelet ridge based on optimal reassigned wavelet scalogram is proposed.Firstly,Morlet wavelet is optimized and reassigned wavelet scalogram is utilized to improve time-frequency concentration of the scalogram.Then,singular value decomposition(SVD) de-noising is applied to the reassigned wavelet scalogram to reduce the influence of the noise.Finally,wavelet ridges are extracted by modulus maximum method and the instantaneous frequency of signal is obtained.The results of experiment and engineering application show that the proposed method is feasible and effective for extracting feature of mechanical vibration signals with low signal-tonoise ratio(SNR).
出处
《振动．测试与诊断》
EI
CSCD
北大核心
2012年第1期62-67,161,共6页
Journal of Vibration,Measurement & Diagnosis
基金
重庆市自然科学基金杰出青年基金资助项目(编号:CSTC2011JJJQ0006)
重庆市科技攻关计划资助项目(编号:CSTC2011AC3063)
重庆大学"211工程"三期建设研究生开放实验室资助项目(编号:S-0916)
关键词
小波脊线
瞬时频率
最优重分配小波尺度谱
故障诊断
wavelet ridge,instantaneous frequency,optimal reassigned wavelet scalogram,fault diagnosis
