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本文建立了分数阶可停振动系统,其可停振动状态的改变对周期策动力敏感,对零均值随机微小扰动不敏感,这事实上为周期未知微弱信号检测提供了一种新的高效检测方法和判别标准.与现有的利用混沌系统的大尺度周期状态变化检测周期未知弱信号的方法需逐一尝试设置不同频率内置信号以便期望与待检周期信号发生共振不同,利用分数阶可停振动系统的可停振动状态变化检测周期未知微弱信号的方法,除了同样具有因为状态变化对周期信号的敏感性而能够实现极低检测门限的特点外,还具有混沌系统信号检测所不具有的优点:1)无需预先估计待检信号的周期;2)无需计算系统状态的临界阈值;3)可停振动状态可由本文设计的指数波动函数可靠地进行判断;4)通过系统微分阶数的变化,将检测系统层次化,从而可得到比整数阶检测系统更低的检测门限,特别是在色噪声环境下,通过选取合适的微分阶数,基于分数阶可停振动系统的微弱周期信号检测法能够大幅度的降低检测门限,在本文的仿真试验中,检测门限可达–182dB.
In this paper, we set up a fractional stop-and-stop system that is sensitive to periodic motive forces and insensitive to random small perturbations of zero mean, which in fact provides a new and efficient method for detecting weak signals with unknown periods And discriminant criterion.Compared with existing methods of detecting periodic unknown weak signals by using large-scale periodic state changes of chaotic systems, it is necessary to set different frequency built-in signals one by one in order to expect different resonance with the signal to be detected, In addition to the same characteristics of low detection threshold due to the sensitivity to periodic signals due to state changes, it also has the advantages of not having chaotic system signal detection: 1 ) No need to pre-estimate the period of the signal to be seized; 2) There is no need to calculate the critical threshold of the system state; 3) The state of the stopable vibration can be reliably judged by the exponential fluctuation function designed in this paper; 4) System-level, which can be lower than the integer order detection system detection threshold, especially in color noises In the acoustic environment, the weak periodic signal detection method based on fractional order stopping vibration system can greatly reduce the detection threshold by selecting the appropriate differential order. In the simulation experiment, the detection threshold can reach -182dB.