基于EEMD和Choi-Williams分布的侵彻加速度信号时频分析  

Penetration Acceleration Signals Time-Frequency Analysis Base on EEMD and Choi-Williams Distribution

作　　者：郝慧艳[1,2,3] 孙运强 李晓峰[3] 刘明杰[3] 

机构地区：[1]中北大学电子测试技术国家重点实验室,山西太原030051 [2]中北大学仪器科学与动态测试教育部重点实验室,山西太原030051 [3]北京理工大学机电学院,北京100081

出　　处：《中北大学学报（自然科学版）》2012年第5期547-551,567,共6页Journal of North University of China(Natural Science Edition)

基　　金：仪器科学与动态测试教育部重点实验室青年基金资助项目(2011);山西省青年科技研究基金资助项目(2012021013-5)

摘　　要：提出了一种基于总体经验模态分解(Ensemble Empirical Mode Decomposition,EEMD)和Choi-Williams分布联合的时频分析算法,该算法采用EEMD算法将信号从频域上分离为若干个固有模态函数之和,再对各分量进行Choi-Williams分布,得到了信号的时频分布特征,有效地消除了信号内部各模态函数之间时频分布的交叉项,从而挖掘信号的本质及相关特征.通过对实测侵彻两层厚度不同的混凝土靶板的加速度信号,采用EEMD和Choi-Williams分布联合时频分析,得出弹体激发的振动模态和靶厚以及着靶速度有关.A time-frequency joint algorithm based on EEMD(Ensemble Empirical Mode Decomposition) and Choi-Williams distribution was put forward. The algorithm decomposed signals into a aggregation of several Intrinsic Mode Functions in the frequency domain adopting the EEMD algorithm.Then processed the components with the Choi-Williams distribution and the time-frequency distribution characteristics of signals could be obtained.The algorithm could eliminate the cross terms of the IMF within the signal and get the nature correlative characteristics of the signal.Through the joint time-frequency analysis of acceleration signals which is measured in Penetration of two concrete targets of different thickness using EEMD and Choi-Williams distribution,the conclusion that the stimulated vibration modes of the projectile are related with the thickness of target and the speed when the projectile contacts with the target.

关 键 词：Choi-Williams分布 EEMD 侵彻加速度信号 时频分析 

分 类 号：TN911.6[电子电信—通信与信息系统]