随机共振控制及在涡街信号处理中应用研究

发布时间：2018-05-31 09:03

本文选题：随机共振 + 涡街流量计　；参考：《中国计量大学》2016年硕士论文

【摘要】：本文根据随机共振系统理论,通过数值仿真与实验结合系统研究了随机共振系统的控制方法,应用于涡街流量计的工程信号处理中。涡街流量计的信号中叠加的干扰噪声会影响测量精度,导致小流量时涡街信号的检测困难。本文针对涡街信号提出了基于随机共振的检测方法,主要完成以下工作:1、通过理论分析与数值仿真,探讨输入信号与非线性双稳系统之间关系,定量分析信号幅值与系统阈值、信号频率与克莱默斯逃逸率之间匹配关系,提出幅值和频率双重调制的系统控制方法,以调制幅值和频率为控制参数,实现信号与双稳系统的匹配。数值仿真表明该控制方式是可行和有效的,不同参数的输入信号可以通过该方法产生随机共振。2、针对涡街信号,提出基于涡街信号标准差的控制参数自适应选取方法,该方法利用涡街信号特征,通过信号标准差估计管道内流速,以此缩小控制参数的搜索范围,提高了信号与双稳系统匹配的效率。3、搭建涡街流量计实验装置,实时采集涡街流量计输出的叠加有现场噪声的旋涡波动信号,通过提出的随机共振方法对涡街信号进行处理,重点分析了小流量情况下涡街信号,处理结果表明,系统输出信号中噪声能量向涡街信号转移,有效增强了涡街信号,提高信号的信噪比,准确获取了涡街频率,实现流量测量,扩展涡街流量计测量下限。
[Abstract]:Based on the theory of stochastic resonance system, the control method of stochastic resonance system is studied by numerical simulation and experiment, which is applied to the engineering signal processing of vortex Flowmeter. The interference noise in the signal of vortex Flowmeter will affect the accuracy of measurement and make the detection of vortex signal difficult when the flow rate is small. In this paper, a detection method based on stochastic resonance for vortex signal is proposed. The following work is accomplished: 1. Through theoretical analysis and numerical simulation, the relationship between input signal and nonlinear bistable system, quantitative analysis of signal amplitude and system threshold are discussed. Based on the matching relationship between signal frequency and Kramer escape rate, a system control method of amplitude and frequency double modulation is proposed. The modulation amplitude and frequency are used as control parameters to realize the matching between signal and bistable system. Numerical simulation shows that the control method is feasible and effective, and the input signal of different parameters can generate stochastic resonance by this method. For vortex signal, an adaptive control parameter selection method based on the standard deviation of vortex signal is proposed. This method uses the characteristics of vortex street signal to estimate the velocity of flow in the pipeline through signal standard deviation, which reduces the search range of control parameters, improves the efficiency of matching signal with bistable system, and builds the experimental equipment of vortex street Flowmeter. The vortex wave signals with field noise are collected from vortex Flowmeter in real time. The vortex signals are processed by the proposed stochastic resonance method, and the vortex signals with small flow rate are analyzed emphatically. The processing results show that, The noise energy in the output signal of the system is transferred to the vortex signal, which enhances the vortex signal effectively, improves the signal-to-noise ratio of the signal, obtains the vortex frequency accurately, realizes the flow measurement, and extends the lower limit of the vortex Flowmeter measurement.
【学位授予单位】：中国计量大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH814

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