微弱信号混沌检测自跟踪扫频控制方法.PDF

31 2 Vol. 31 No. 2 2014 2 Control Theory Applications Feb. 2014 DOI: 10.7641/CTA.2014.30105 , , , (1. , 310018; 2. , 300401; 3. , 318000) : , , . , . , , , , , , . . : ; ; ; ; Duffing : TP273 : A Self-tracing-frequency control in weak signal chaotic detection ZHAO Wen-li , FAN Jian , WU Min , WANG Wan-qiang (1. School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou Zhejiang 310018 China; 2. School of Mechanical Engineering, Hebei University of Technology, Tianjin 300401 China; 3. School of Mechanical Engineering, Taizhou University, Taizhou Zhejiang 318000 China) Abstract: Chaotic detection can be applied to extract the weak sinusoidal signal submerged in noise background. However, there are few effective ways to construct the chaotic detection system for detecting a continuous frequency band signal. We elaborate two chaotic detection methods, the fixed-threshold-value method and the floating-threshold-value method, and analyze their advantages and shortcomings. On this basis, we propose the multi-frequency-band threshold- value transform method to deal with the problems existing in the above two mentioned methods, and design the self- frequency-tracing circuitry accordingly. The operation of this circuitry is validated by hardware experiments. Experimental results show that weak medium-low frequency signals can be detected from the background noise by using this method. Key words: chaos theory; signal detection; self-tracing-frequency; wea