摘要
在机械故障诊断中,基于循环平稳的信号分析方法逐渐受到人们的重视,本文主要分析了谱相关函数(二阶循环平稳统计量)的解调原理,为机械设备故障诊断中的解调分析方法提供了一种新的思路。根据两信号乘积的谱相关函数等于两信号的谱相关函数在频率和循环频率域的双重卷积,推导出调幅信号的谱相关函数,由于在两个频率域的双重卷积使得谱相关函数在频率和循环频率域均具有解调功能,这样得到的双重解调信息提高了分析结果的可靠性。通过分析并仿真发现这种基于谱相关函数的解调方法还能同时对调幅和调频信号进行解调。
Cyclostationary signal processing is gradually gaining importance in the fault diagnosis of rotating machine. This paper is dedicated to analyzing the Spectral Correlation Function (SCF), which is the second-order cyclostationary statistic. The SCF for the multiplication of two wave signals is the double convolution of these of the corresponding signals, and the amplitude modulated signal can be decomposed as multiplication of two periodic signals. Therefore, the SCF of amplitude modulated signal is derived from these theories. The modulated-frequency can be obtained from the SCF of amplitude modulated signal because of the double convolution in both frequency domains. This demodulation method based on SCF is applicable to both amplitude modulated and frequency modulated signals, and may serve as a guideline for demodulation analysis in machine fault analysis.
出处
《机械科学与技术》
CSCD
北大核心
2005年第7期771-774,共4页
Mechanical Science and Technology for Aerospace Engineering
基金
国家自然科学基金项目(50175068)资助
关键词
循环平稳
谱相关函数
解调
Cyclostationarity
Spectral correlation function
Demodulation
