摘要
研究了Duffing振子对策动力参数与初始值敏感的一致性,基于Duffing振子在不同初值时的仿真发现,不同初值情况下,混沌振子从混沌态过渡到大尺度周期态的过渡过程存在"周混渐变"和"混周渐变"两种,并且在过渡过程中,策动力增大的方向为周期态延时增长、混沌态延时缩短的方向,提出了利用过渡态检测微弱正弦信号的方法,基于"混周渐变"过渡态的检测,能检测的最低信噪比可达-60.7 dB,实验结果表明,这种方法非常适合检测地磁扰动信号Pc2小类中的确定频率信号。
The consistency of the sensitive dependence on initial conditions and driving force parameter is re- searched. Under the difference initial conditions, Duffing oscillator is simulated. It is found that the transition process of Duffing oscillator from chaos state to the large scale period state can be divided into ＂period-to-chaos transition＂ and ＂chaos-to-period transition＂, and the greater the driving force is ,the longer the delay time of the period state ,the shorter the delay time of the chaos state is. A new method is proposed to detect weak sinusoidal signal by using the transition state. The＇lowest signal-to-noise ratio based on the transition state of ＂chaos-to-period transition＂ which can be detected is down to - 60.7 dB. Experimental result shows that the proposed method especially adapted to detect the assigned signal in subclass Pc2 of geomagnetic ultra-low-frequency （ULF） signal.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2012年第12期2857-2862,共6页
Chinese Journal of Scientific Instrument
关键词
混沌
初值
稳态
过渡态
chaos
initial value
stable state
transient state
