解调分析中差频现象的理论分析及细化解调/频谱分析集成算法  

Difference Frequency Effect in Demodulation and an Integrative Algorithm for Zoom Demodulation/Spectrum Analysis

作　　者：朱利民[1] 熊有伦[1] 

机构地区：[1]华中科技大学机械学院机械电子信息工程系,武汉430074

出　　处：《振动工程学报》2001年第4期409-413,共5页Journal of Vibration Engineering

基　　金：国家"九五"攀登计划资助项目 (编号 :PD95 2 190 3)

摘　　要：应用泰勒级数展开方法研究了解调分析中的差频现象 ,指出信号解调前必须滤除与调制信息无关的加性频率成分。为方便实际应用 ,提出了细化解调 /频谱分析集成算法 ,算法中两种信号分析方法均由带通滤波、Hibert变换和重抽样三个步骤组成 ,算法实现时将这三个步骤集成在一个复解析带通滤波过程之中 ,具有很高的计算效率 。Demodulation is a widely used signal processing method for machine fault diagnosis. By using Taylor series expansion, the difference frequency effect in demodulation is theoretically analyzed. It is suggested that the technique of demodulation should be combined with that of band-pass filtering, then an integrative algorithm for zoom demodulation and spectrum analysis is proposed, which is of great benefit to software realization and engineering application. The flows of the two signal processing methods, in the integrative algorithm, are both composed of three steps, i.e., band-pass filtering, Hilbert transform and resampling. The three operations are integrated into a single analytical band-pass filtering procedure. Therefore the presented algorithm has high computational efficiency, and its effectiveness is verified by the treatment of synthetic signal.

关 键 词：信号处理 频谱 解调分析 差频 集成算法 滤通波 机械故障诊断 

分 类 号：TH17[机械工程—机械制造及自动化] TN911.7[电子电信—通信与信息系统]