余明慧 - 201307005 - 基于分布式光纤传感的周界警戒系统关键(3)

Abstract

Abstract

With the development of the society and the progress of science ,a large number of social wealth, heavily military and the important facilities are need security products for effective prevention to ensure their safety. Although, traditional security alarm system has achieve a certain security defense effect, but there are some technical defects. Optical fiber perimeter alarm system based on distributed optical fiber sensing can recognise timely, and has the function of long-distance monitoring, precise positioning, and low rate of false positives ect.Whitch can overcome the shortcoming of traditional perimeter security system. Therefore, it has extensive application prospect in the civil and military, and become a hot spot of research at home and abroad.

In this paper, based on the study of distributed optical fiber sensing intrusion technology, the main research contents are as follows:

First, this paper expounds the basic principle and composition of distributed optical fiber perimeter alarm system, puts forward the system of sensor type, working band, positioning accuracy and positioning relative error and other technical indicators. Studied tkey technologies of system,such as:the distributed optical fiber sensing technology, localization algorithm, pattern recognition technology, signal demodulation technology, system detection range. And clear mainly two key techniques of this topic research: pattern recognition technology and positioning algorithm.

Secondly, distributed optical fiber sensing systems are analyzed with the method of time domain. Analyzed the invasion of external artificial interference, breeze and drizzle interference, small animals climb interference, cyclical weaker mechanical interference of typical response characteristics of these four types , and using Labview software simulation to verifying.

Then, the paper discusses several distributed sensor positioning methods based on the interference principle.This paper studies the measuring principle of cross-correlation method to measuring time delay.Advanced the time delay estimation algorithm to make signal peak even more prominent, so that time lag will more accurate.

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武汉工程大学硕士学位论文

Finally, according to the design index choosing ASE light source module, the G652D

sensing optical fiber, the LSM - PIN photodetector, the 2 x 2 fiber coupler, PCI8521 data acquisition card to complete the design of the system. Using Labview software to simulat the system under the condition of invasions in different position, the results meet the requirements of system design .

The research and the design of optical fiber alert system has its theoretical innovation and guidance to engineering practice.

Keywords: Distributed optical fiber sensor; Perimeter alarm;Pattern recognise; Position technology; The system overall design

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目 录

目 录

摘 要 ....................................................... I Abstract ................................................... III 目 录 ........................................................ V 第1章 绪 论 ................................................. 1

1.1研究背景及意义 ....................................... 1 1.2周界警戒系统国内外研究现状 ........................... 2

1.2.1传统周界警界系统及性能对比 ..................... 2 1.2.2光纤周界警戒系统国内外研究现状 ................. 4 1.2.3光纤周界警戒系统发展趋势 ....................... 6 1.3论文主要内容安排 ..................................... 8 第2章 系统原理、组成及关键技术 .............................. 9

2.1系统基本原理 ......................................... 9 2.2系统组成及特点 ...................................... 11

2.2.1系统组成 ...................................... 11 2.2.2主要模块功能 .................................. 11 2.2.3系统特点 ...................................... 12 2.3系统主要关键技术 .................................... 12

2.3.1分布式光纤传感技术 ............................ 13 2.3.2模式识别技术 .................................. 17 2.3.3定位技术 ...................................... 19 2.3.4信号解调技术 .................................. 19 2.3.5系统探测距离技术 .............................. 20 2.4本章小结 ............................................ 21 第3章 数据采集与模式识别技术研究 ........................... 23

3.1 LabVIEW介绍 ........................................ 23 3.2数据的采集 .......................................... 23

3.2.1数据采集卡原理 ................................ 23 3.2.2 数据采集模块程序 .............................. 24 3.3典型干扰信号的响应特征 .............................. 26 3.4信号模式识别程序设计 ................................ 28

3.4.1作用力的平均幅度VI ............................ 28 3.4.2自相关VI ...................................... 28 3.4.3最大最小能量比值VI ............................ 30 3.4.4峰值统计VI .................................... 31

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武汉工程大学硕士学位论文

3.5仿真结果与分析 ...................................... 31 3.6本章小结 ............................................ 34 第4章 定位技术研究 ......................................... 35

4.1干涉型分布式光纤传感系统定位技术研究 ................ 35

4.1.1基于萨格奈克干涉原理的定位技术 ................ 35 4.1.2基于双波长萨格奈克干涉原理的定位技术 ........... 36 4.1.3基于双马赫-泽德干涉原理的定位技术.............. 37 4.1.4基于萨格奈克/马赫-曾德尔干涉原理的定位技术 ..... 37 4.1.5各种定位技术优缺点对比 ........................ 38 4.2基于双马赫-泽德干涉原理的定位系统 ................... 39

4.2.1定位系统等效光路图 ............................ 39 4.2.2定位计算 ...................................... 40 4.3时间延迟算法 ........................................ 41

4.3.1特征点时延算法 ............ …… 此处隐藏：4864字，全部文档内容请下载后查看。喜欢就下载吧 ……