基于直线型Sagnac的分布式光纤振动检测定位系统

发布时间：2018-06-01 03:45

本文选题：光纤传感 + 振动检测　；参考：《太原理工大学》2017年硕士论文

【摘要】：分布式光纤传感技术具有长距离、耐腐蚀、抗电磁干扰等优点,被广泛应用于周界安防、管道监测、桥梁建筑、大坝防护等领域,主要测量对象包括有振动、温度、应力等。其中振动测量在许多领域中都有广泛的应用需求,如在周界安防中,通常采用人工巡逻或者电子摄像头的方式,对外界入侵行为进行预判。然而,随着周界安防距离的增加,传统的检测手段所耗费的人力成本将显著提高,因此迫切需要一种可满足长距离周界安防预警的振动检测系统。此外管道输送领域中,所需的输送管道动辄可达成百上千公里,并且管道埋藏在距离地表数米的地下,距离的增加和地下的铺设方式使得人工巡检存在成本高、效率低以及可靠性差等弊端。分布式光纤振动检测技术则因其具备价格低、效率高、性能好等众多优点,已成为长距离安全监测的首选方案,显著节省了人工成本并提高了检测效率。本文设计了一种基于直线型Sagnac的分布式光纤振动检测定位系统,通过光纤实现对振动信号的感知、采集和显示,设计了用于振动模拟的嵌入式相位调制模块,并开发了LabVIEW上位机检测软件,实现对振动信号的实时检测与显示。同时借助振动信号频谱中的多级零频点特性,提出了一种用于系统优化的多级零频点定位算法。本文主要进行了以下方面的研究:(1)研究直线型Sagnac分布式光纤振动检测定位系统的传感机理,建立外界振动信号检测的理论模型。(2)搭建直线型Sagnac分布式光纤振动检测定位系统,分析振动检测方法与定位原理。(3)针对传统振动激励方法所存在的问题,将嵌入式技术与压电陶瓷技术相结合,设计出一种用于振动模拟的嵌入式相位调制模块,实现对传感系统的调试与标定。(4)设计出LabVIEW上位机数据采集软件,选择高速数据采集卡,设计采集卡底层驱动和用户操作界面,实现对振动信号的实时采集。(5)分析传统直线型Sagnac振动传感系统的定位理论及算法,针对传统定位算法误差较大的问题,提出将多级零频点用于定位的优化方法,并通过实验验证得出,合理使用多级零频点能够提升系统的定位精度。基于直线型Sagnac的分布式光纤振动检测定位系统,以光纤传感技术为基础,能够实时观察到整个传感链路中的振动状况,从而提升振动检测的自动化水平,并可在各类复杂环境下的长距离振动检测领域进行推广。
[Abstract]:Distributed optical fiber sensing technology has many advantages such as long distance, corrosion resistance, electromagnetic interference resistance and so on. It is widely used in perimeter security, pipeline monitoring, bridge building, dam protection and so on. The main measurement objects include vibration, temperature, stress and so on. Vibration measurement is widely used in many fields, for example, in perimeter security, manual patrol or electronic camera is usually used to pre-judge the intrusion behavior of the outside world. However, with the increase of perimeter security distance, the cost of traditional detection methods will increase significantly. Therefore, a vibration detection system is urgently needed to meet the long range perimeter security warning. In addition, in the field of pipeline transportation, the required transportation pipeline can easily reach hundreds of kilometers, and the pipeline is buried several meters underground from the surface of the earth. The increase of distance and the way of laying underground make the cost of manual inspection high. Low efficiency and poor reliability and other drawbacks. Because of its advantages of low price, high efficiency and good performance, distributed optical fiber vibration detection technology has become the first choice for long distance safety monitoring, which has significantly saved labor cost and improved detection efficiency. In this paper, a distributed optical fiber vibration detection and positioning system based on linear Sagnac is designed. The sensing, collecting and displaying of the vibration signal are realized through the optical fiber, and the embedded phase modulation module is designed for vibration simulation. The software of LabVIEW upper computer is developed to detect and display vibration signal in real time. At the same time, a multi-level zero-frequency location algorithm for system optimization is proposed by virtue of the multi-level zero frequency point characteristics in the vibration signal spectrum. This paper mainly studies the following aspects: 1) study the sensing mechanism of linear Sagnac distributed optical fiber vibration detection and positioning system, and establish the theoretical model of external vibration signal detection. Build a linear Sagnac distributed optical fiber vibration detection and positioning system. This paper analyzes the vibration detection method and positioning principle. (3) aiming at the problems existing in the traditional vibration excitation method, an embedded phase modulation module for vibration simulation is designed by combining the embedded technology with the piezoelectric ceramic technology. To realize the debugging and calibration of the sensing system. (4) to design the data acquisition software of the LabVIEW upper computer, select the high-speed data acquisition card, design the bottom driver and user interface of the data acquisition card. The localization theory and algorithm of the traditional linear Sagnac vibration sensing system are analyzed. Aiming at the problem that the error of the traditional positioning algorithm is large, the optimization method of using multi-stage zero frequency to locate the vibration signal is put forward. The experimental results show that reasonable use of multi-level zero-frequency points can improve the positioning accuracy of the system. The distributed optical fiber vibration detection and positioning system based on linear Sagnac, based on the optical fiber sensing technology, can observe the vibration status of the whole sensing link in real time, thus improving the automatic level of vibration detection. It can be popularized in the field of long distance vibration detection in various complex environments.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212;TH825

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