噪声非线性效应的增强与弱涡街信号检测方法

摘要

噪声与非线性势场相互作用产生的效应能够助长微弱信号。针对小流量产生的涡街信号较弱而难以检测的问题，从增强噪声非线性效应的角度出发，比较了不同非线性形式势函数下的噪声效应，构造了对称抛物线势函数。理论分析和数值仿真结果表明具有对称抛物线势函数的系统输出有较高的信噪比。提出了一种利用对称抛物线系统增强噪声效应的检测弱涡街信号方法，实测弱涡街信号检测结果表明该方法能有效获取小流量涡街信号的特征频率。%The effects generated by interaction of noise and nonlinear potential field can enhance weak signals. Aiming at the problem that weak vortex signals generated by low flowrate were difficult to detect,from the viewpoint of enhancing noise nonlinear effects,the noise effects of different nonlinear potential functions were compared,a symmetric parabolic potential function was constructed.The theoretical analysis and numerical simulation indicated that a system with the symmetric parabolic potential function has a higher SNR.A method to detect weak vortex signals was proposed with a symmetric parabolic system to enhance noise effects.The detection results of real vortex signals indicated that this method can effectively get characteristic frequencies of low flow-rate vortex signals.