信号瞬时频率直接计算法与Hilbert变换及Teager能量法比较  

Comparison of Instantaneous Frequency Directed Computing Method and Hilbert Transform and Teager Energy Method

作　　者：任达千[1,2] 杨世锡[1] 吴昭同[1] 严拱标[1] 孟庆波[2] 

机构地区：[1]浙江大学机械工程学系,杭州310027 [2]浙江机电职业技术学院,杭州310053

出　　处：《机械工程学报》2013年第9期42-48,共7页Journal of Mechanical Engineering

基　　金：国家高技术研究发展计划(863计划;2007AA04Z424);浙江省自然科学基金(Y1110582);浙江机电职业技术学院孵化基金(04090341)资助

摘　　要：针对Hilbert变换求取信号瞬时频率时会出现没有物理意义的负频率现象,研究基于局域均值分解的瞬时频率直接计算方法。给出相位展开分段计算方法的详细计算步骤。直接法与直接正交法进行了比较,直接法和直接正交法在数学上相等,计算结果相同,可以认为是同一种方法。直接法也与Hilbert变换、Teager能量方法进行比较。仿真和试验结果表明,直接法计算结果能很好地反映信号的相位调制现象,没有明显的端点效应,不会出现负频率现象。直接法应用于旋转机械振动信号的分析,取得良好效果。In order to resolve the no physical meaning negative frequency phenomena in Hilbert transform, the instantaneous frequency directed calculation method based on the local mean decomposition is researched. The steps of phase unwrap is presented. The direct method is compared with the direct quadrature. Because direct method and direct quadrature are equal in mathematics and have the same calculating result, direct method and direct quadrature can be thought as the same method. Direct method is also compared with the Hilbert transform, Teager energy method. Simulation and experimental results show that the direct method well reflects the signal phase modulation phenomenon, there is no obvious boundary distortion, and the instantaneous frequency is always positive. The direct method is applied in the analysis of rotating machinery vibration signals and a good result is achieved.

关 键 词：瞬时频率 局域均值分解 直接法 故障诊断 HILBERT变换 Teager能量法 

分 类 号：TH113[机械工程—机械设计及理论] TB533[理学—物理]