将两个单一双稳系统经非线性耦合而成耦合双稳系统,其中一双稳系统为被控系统,受到弱输入周期信号作用;另一双稳系统为控制系统,受到控制信号的作用.分析控制信号作用下的耦合双稳系统的双共振特性,当控制信号频率两倍于弱输入周期信号频率时,耦合双稳系统中发生控制系统中的共振与被控系统的随机共振.提出基于双共振的随机共振增强方法,并设计耦合双稳系统双共振硬件电路,电路系统试验结果证实了耦合双稳系统中存在着双共振,且能有效增强被控系统中的随机共振.将该双共振电路系统应用于实际轴承故障信号检测中,系统输出功率谱在特征频率处的谱值大幅增强,可准确检测出强噪声背景中的微弱轴承故障信号,为基于随机共振原理的信号检测电路设计提供一种新方案,具有良好的应用前景.
The coupled bistable system is composed of two single bistable systems by means of nonlinear coupling.One of the bistable systems is controlled system which is subjected by the weak periodic signal,and the other is controlling system which is under the action of control signal.The dual-resonance characteristics of coupled bistable system under the controlling signal action were analyzed.When the frequency of control signal is twice of the weak periodic signal's frequency,the coupled bistable system can exist resonance in controlling system and stochastic resonance in controlled system,and a method based on dual-resonance to enhance stochastic resonance is proposed.A coupled bistable system hardware circuit system was designed based on dual-resonance.Experimental results confirm that there exists dual-resonance in coupled bistable system and the dual-resonance can enhance stochastic resonance greatly.Put the hardware circuit system into the detection of bearing fault signal,the power spectrum of coupling systems' output at the eigen frequency increase greatly,and it can detect weak signal of bearing fault effectively.A novel solution to detect the weak signal Based on the principle of stochastic resonance is provided,and it has a good application prospect.