Chen系统在微弱信号检测中的应用

Application of Chen's system to detecting weak harmonic signals

微弱谐波信号的灵敏检测具有重要的实际应用意义,本文利用受控Chen系统来实现强噪声背景下的这种检测.因动力系统可分解为慢变系统与快变系统的叠加,这里用平均法对检测系统进行处理得到慢变系统,并获取使系统由周期轨道突变为稳定平衡点的检测参数临界值.通过调节检测参数,观测系统状态变量的变化可判断待测信号是否存在.仿真结果表明,此方法可以准确检测出强噪声背景下的微弱谐波信号.与目前其他基于混沌振子的检测方法相比,该方案对噪声具有更强的免疫性,而且可通过理论分析得出检测参数阈值的准确范围,有利于在相关领域推广应用.

The detection of weak harmonic signals has important practical value. In this paper, the detection of weak harmonic signals in strong noise is realized with the controlled Chen＇s system. Dynamics can be divided into slowly varying dynamics and fast varying dynamics, so a slowly varying dynamics is obtained by an averaging method. The critical values of detection parameters are determined, which lead to a sudden change of system dynamical behavior from periodic orbit to stable equilibrium point. Weak harmonic signals can be detected by adjusting the detection parameters and observing the change of system variables. Simulation results show that weak harmonic signals in strong noise can be detected accurately with this system. Compared with existing detection methods with chaotic oscillator, this method is of stronger immunity to noise, and the accurate range of parameter threshold can be obtained through theoretical analysis, which enables its popularization and application in relevant fields.