基于Lorenz混沌同步系统的未知频率微弱信号检测  

Unknown frequency weak signal detection based on Lorenz chaotic synchronization system

作　　者：李国正[1] 谭南林[1] 苏树强[1] 张驰[1] LI Guozheng;TAN Nanlin;SU Shuqiang;ZHANG Chi(School of Mechanical Electronic and Control Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学机械与电子控制工程学院,北京100044

出　　处：《振动与冲击》2019年第5期155-161,共7页Journal of Vibration and Shock

基　　金：中央高校基本科研业务费专项资金资助(2017RC014);国家自然科学基金(51505154; 61527812)

摘　　要：针对现有混沌类检测方法存在的不足,提出一种基于混沌同步系统测量强噪声背景下微弱信号频率值的新方法。该方法利用Lorenz混沌系统自身的初值敏感性、噪声免疫性和混沌系统的可同步性,采用驱动-响应法构建同步检测系统对微弱信号进行降噪处理,再结合多信号分类算法处理所得到的同步误差信号,最终实现微弱信号的频率测量。该方法有效解决了单Duffing振子参数设定复杂、运行状态转换时间长和状态判定困难的问题,也无需采用复杂的混沌系统阵列结构求解待测信号的频率值。仿真和实验结果表明新方法能够准确检测出微弱信号的频率,进一步完善了现有混沌类检测方法,为其应用于实际工程提供了新的思路。Aiming at shortcomings of existing chaotic detection methods,a new method based on chaotic synchronization system was proposed to measure frequency values of weak signals under strong noise background.With the proposed method,characteristics of Lorenz chaotic system,such as,sensitivity to initial values,immunity of noise and synchronism were used,and the drive-response method was adopted to construct a synchronization detection system to de- noise weak signals.Using the multi-signal classification (MUSIC) algorithm,the synchronization error signal was processed to realize frequency measurement of weak signals.It was shown that this method can effectively solve problems of single Duffing oscillator’s complex parameter setting,long operation state conversion time and difficult state determination;it does not need complex chaotic system array structure to solve frequency values of weak signals to be measured.The simulation and test results showed that the new method can correctly detect frequency values of weak signals,and further improve the existing chaotic detection methods.The results provided a new idea for application of chaotic synchronization systems in practical engineering.

关 键 词：混沌同步 MUSIC算法 DUFFING振子 频率检测 

分 类 号：TN911.23[电子电信—通信与信息系统]