基于改进经验AM-FM解调的复杂信号瞬时特征分析方法  

Instantaneous Characteristics Analysis Method for Complicated Signals Based on Improved Empirical AM-FM Demodulation

作　　者：胡海峰[1] 胡茑庆[1] 秦国军[1] 

机构地区：[1]国防科技大学机电工程与自动化学院,湖南长沙410073

出　　处：《国防科技大学学报》2011年第2期119-124,共6页Journal of National University of Defense Technology

基　　金：国家自然科学基金资助项目(50675219);湖南省杰出青年科学基金资助项目(08JJ1088)

摘　　要：分析了Hilbert变换在计算复杂单分量信号瞬时特征时存在的不足,研究了一种称为经验AM-FM解调的信号瞬时特征计算方法,并对算法进行了改进。针对其在计算瞬时频率时易受噪声影响的不足,提出将该算法与加权平滑相位差分法相结合来抑制噪声的影响。结合经验模式分解和改进的经验AM-FM解调算法,提出了一种适合复杂多分量信号解调分析和瞬时特征计算的方法。数值仿真和实验数据验证了该改进方法的有效性。Some limitations of the Hilbert transform（HT） for computing instantaneous characteristics of complicated mono-component signals were analyzed.As an enhancement of the HT,an algorithm named empirical AM-FM（amplitude and frequency modulation） demodulation was investigated and then improved.Firstly,the weighted smoothing phase-difference method was applied to this demodulation algorithm to increase the precision of instantaneous frequency for noisy signals.Secondly,by combining the Empirical Mode Decomposition（EMD） and the improved empirical AM-FM demodulation algorithm,a method suitable for instantaneous characteristics extraction of complicated multi-component signals was proposed.The validity of the improvements was confirmed by numerical simulations and experimental signals.

关 键 词：HILBERT变换 经验AM-FM解调 改进算法 经验模式分解 瞬时频率 瞬时幅值 

分 类 号：TH114[机械工程—机械设计及理论]