基于布里渊光时域分析技术的围栏入侵检测方法的研究

发布时间：2018-06-26 23:59

本文选题：布里渊光时域分析 + 光纤应变　；参考：《电子科技大学》2017年硕士论文

【摘要】：基于布里渊光时域分析(Brillouin Optical Time Domain Analysis,BOTDA)技术的传感器具有检测距离长,测量精度高,抗外界干扰能力强等优势,而围栏入侵检测系统在周界安防领域有着广阔的应用前景,因此,研究基于BOTDA围栏入侵检测系统具有重要的现实意义。本论文通过查阅国内外文献和调研重要场所的周界安防中的围栏入侵检测技术的现状后,结合受激布里渊散射独特的优点,设计了一种基于BOTDA围栏入侵检测系统,该系统克服了传统BOTDA分布式光纤传感器测量耗时多,检测反应慢的缺点,并创新地提出了重心频率的算法,对几种围栏入侵的检测方法(以检测光纤应变为例)进行了深入研究,最后通过相关实验验证了该系统对围栏入侵检测的可行性。本论文主要研究内容如下:1.简要介绍了布里渊散射理论,分析了光纤的传感机理,重点分析了布里渊频移和布里渊光功率与光纤应变的关系,为本论文的系统设计奠定了理论基础;2.重点研究了实验传感数据处理方法和系统中的软件设计方案,介绍了均值滤波对传感信号处理的原理,分析了布里渊频移拟合与寻峰技术;接着重点分析了布里渊频移检测法和重心频率检测法的检测原理;最后简要分析了系统性能指标,包括系统信噪比、传感精度和空间分辨率,为后续的实验研究指明了方向;3.设计并搭建了基于BOTDA围栏入侵检测系统。首先利用光谱分析仪获取+1阶的边带光波构成了增益型的BOTDA系统;接着通过RS232串口通信显示界面发送指令和采集界面的初始化设置获取到了实验所需的原始光信号;然后利用VC++中的MFC模块设计程序实现了对实验数据的采集和传感信号的显示;接着运用布里渊频移检测法、重心频率检测法以及原始光信号强度检测法分别对光纤应变检测实验并对相应的检测结果进行了分析。4.对本系统性能指标做了相关测试和分析,得到本系统的传感精度为25 g,实验测定的布里渊频移应变系数为0.5983MHz/g,系统的空间分辨率为4m。最后提出了阈值法、谱分析法来对围栏入侵的检测方法,并给出了谱分析法的模拟测试实施方案和实验结果分析。上述研究结果表明,本论文设计的系统及检测方法应用于围栏入侵监测是可行的。
[Abstract]:The sensor based on Brillouin Optical time Domain Analysis (Brillouin Optical time Domain Analysis) technology has the advantages of long detection distance, high measurement precision and strong ability to resist external interference. It is of great practical significance to study the intrusion detection system based on BOTDA fence. After consulting domestic and international literature and investigating the present situation of fence intrusion detection technology in perimeter security of important sites, combining the unique advantages of stimulated Brillouin scattering, a BOTDA fence intrusion detection system is designed. The system overcomes the shortcomings of the traditional BOTDA distributed optical fiber sensor, which is time-consuming and slow to detect, and puts forward the algorithm of center of gravity frequency innovatively. In this paper, several detection methods of fence intrusion (taking fiber strain detection as an example) are studied in depth. Finally, the feasibility of the system for detecting fence intrusion is verified by relevant experiments. The main contents of this thesis are as follows: 1. The Brillouin scattering theory is introduced briefly, the sensing mechanism of optical fiber is analyzed, and the relationship between Brillouin frequency shift, Brillouin optical power and fiber strain is analyzed, which lays a theoretical foundation for the system design of this thesis. The experimental data processing method and the software design scheme of the system are studied emphatically. The principle of the mean value filter for the sensing signal processing is introduced, and the Brillouin frequency shift fitting and peak-seeking technology are analyzed. Then the detection principle of Brillouin frequency shift detection method and center of gravity frequency detection method is analyzed emphatically. Finally, the system performance indexes, including system signal-to-noise ratio, sensing precision and spatial resolution, are briefly analyzed. An intrusion detection system based on BOTDA fence is designed and built. At first, the gain BOTDA system is constructed by obtaining the first order side band light wave by the spectrum analyzer, and then the original optical signal is obtained through RS232 serial port communication display interface sending instruction and the initialization setting of the acquisition interface. Then we use MFC module in VC to design the program to collect the experimental data and display the sensing signal, and then use Brillouin frequency shift detection method. Barycenter frequency detection method and original light signal intensity detection method are used to test the strain of optical fiber, and the corresponding results are analyzed. The sensor precision is 25 g, the Brillouin frequency shift strain coefficient is 0.5983 MHz / g and the spatial resolution of the system is 4 m. Finally, the threshold method and spectral analysis method are proposed to detect the fence intrusion, and the implementation scheme and the experimental results of the spectral analysis method are given. The results show that the system and detection method designed in this paper are feasible for fence intrusion detection.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN253;TP274

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