随机共振在微弱周期冲击信号检测中的应用

发布时间：2018-03-11 20:42

本文选题：随机共振　切入点：微弱信号检测　出处：《天津大学》2012年硕士论文　论文类型：学位论文

【摘要】：在机械故障诊断领域中,微弱信号检测技术得到了越来越多的重视。在故障发生的早期阶段,故障的特征往往隐藏在背景噪声中,难以被察觉出来,为事故发生埋下隐患。传统的检测方法往往认为噪声是微弱信号检测中的不利因素,但随着微弱信号检测技术日趋发展成熟,人们发现在某些非线性系统中,噪声的加入反而会增加信号的信噪比,这就是随机共振现象。在过去的二十年中,随机共振理论及研究不断发展,在微弱信号检测领域有着突出的表现。本文以随机共振在机械故障检测中的应用为目的,分析了随机共振在工程应用中的局限性,并且针对这些局限性提出了解决方法,并以轴承故障信号为例,将随机共振应用于机械故障检测之中。本文的主要研究内容包括: 1.分析了随机共振理论在应用于工程实践中时可能碰到的问题,分别讨论了信号幅值、噪声强度及信号频率不满足随机共振理论中限制条件时对随机共振检测结果的影响,并逐一针对这些限制条件提出了解决方法。 2.通过实验仿真的方法,分析了随机共振中的非线性响应现象,并研究了非线性响应对随机共振在微弱信号检测中带来的影响。 3.分析了多个频率驱动信号情况下的随机共振现象,并研究了多频信号对随机共振检测效果的影响。 4.根据以上的分析,提出了随机共振前处理的概念,使得信号在经过前处理后满足随机共振现象产生的条件,以达到合理检测微弱信号的目的。 5.研究了随机共振对冲击信号的检测能力,之后分析了滚动轴承故障信号的特征,结合共振解调法,成功地提取出了淹没在强噪声中的故障特征频率,验证了随机共振在故障诊断领域中的实用性和有效性。
[Abstract]:In the field of mechanical fault diagnosis, more and more attention has been paid to the weak signal detection technology. In the early stage of the fault, the fault features are often hidden in the background noise, which is difficult to detect. Traditional detection methods often think that noise is a disadvantage factor in weak signal detection, but with the development of weak signal detection technology, it is found that in some nonlinear systems, In the past two decades, the theory and research of stochastic resonance have been developing continuously, and it has been outstanding in the field of weak signal detection. Aiming at the application of stochastic resonance in mechanical fault detection, this paper analyzes the limitations of stochastic resonance in engineering application, and puts forward a solution to these limitations, and takes the bearing fault signal as an example. Stochastic resonance is applied to mechanical fault detection. The main contents of this paper are as follows:. 1. The problems that may be encountered in the application of stochastic resonance theory in engineering practice are analyzed. The effects of signal amplitude, noise intensity and signal frequency on the detection results of stochastic resonance are discussed when the limited conditions of stochastic resonance theory are not satisfied. The solutions to these limitations are put forward one by one. 2. The phenomenon of nonlinear response in stochastic resonance is analyzed by the method of experimental simulation, and the influence of nonlinear response on the weak signal detection of stochastic resonance is studied. 3. The phenomenon of stochastic resonance in the case of multiple frequency driving signals is analyzed, and the influence of multi-frequency signal on the detection effect of stochastic resonance is studied. 4. According to the above analysis, the concept of stochastic resonance pre-processing is put forward, which makes the signal satisfy the condition of producing stochastic resonance after pre-processing, so that the weak signal can be detected reasonably. 5. The detection ability of stochastic resonance to impact signal is studied, then the characteristics of rolling bearing fault signal are analyzed, and the frequency of fault characteristic submerged in strong noise is extracted successfully by the method of resonance demodulation. The practicability and validity of stochastic resonance in fault diagnosis are verified.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH165.3

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