【作者】 张春丽；

【导师】 张颖；

【作者基本信息】 燕山大学 ， 测试计量技术及仪器， 2009， 硕士

【摘要】 光纤Bragg光栅(FBG)是近几年发展最为迅速的光纤无源器件之一。由于FBG对特定波长的光具有反射作用,并且其反射中心波长随着温度、应变等物理量的变化而变化,具有优良的温度和应变响应特性,所以它在传感领域有着广泛的应用前景。FBG传感器的主要优点之一是便于构成分布式传感系统,而构成分布式传感系统的关键技术之一是复用技术,包括波分复用(WDM)、时分复用(TDM)、空分复用(SDM)及它们的组合复用技术。FBG的复用技术可以减少成本和传感系统的体积。FBG分布式解调系统的检测精度决定着整个系统的精度,所以解调系统是FBG分布式传感系统的核心。本文是以分布式FBG传感解调系统的设计和应用为目的。主要研究了以下几个方面的问题:首先,在对国内外研究现状进行了深入分析的基础上,介绍了当前FBG传感技术的发展趋势及其在实际应用中需要解决的几个主要问题。其次,从理论上推导了FBG的温度和应变的传感特性以及二者的交叉敏感度。并通过实验证明了FBG传感器的中心波长与应变有良好的线性关系。具体分析了FBG分布式解调的原理及常用的解调方法,介绍了分布式系统中常用的几种复用方法,指出了分布式解调所面临的一些问题。再次,在上面分析的基础上设计了一种基于非平衡M-Z干涉解调技术的FBG分布式传感解调系统。通过对光路、电路等硬件部分的设计,利用DAQ2005数据采集卡采集数据,并用频谱分析的思想通过Lab VIEW软件进行编程,实现了3个通道同时解调。最后,设计了基于Lab VIEW的仿真信号相位差计。数据采集模块用Lab VIEW自带的信号发生模块代替,并设计添加随机噪声干扰、A/D转换量化误差等仿真条件,使得处理后的信号具有和采集实验数据的信号有相同的特性,这样就让仿真实验更具有研究价值。更多还原

【Abstract】 As one of the most rapidly developed passive fiber devices in recent years, Fiber Bragg Grating (FBG) can reflect special wavelength which changes with temperature or strain. FBG sensor is a new type of sensor, and it has excellent temperature and strain response properties which is a novel fiber photonic device with rapid development in these years and has broad and good applications in the fiber sensing field. The key technology to realize distribute measure is multiplexing, which includes Wavelength division multiplexing (WDM), Time division multiplexing (TDM), spatial division multiplexing (SDM) and the combination of any of them.The multiplexing about FBG not only reduces the cost of sensors, but also minishes the volume of the whole system. The demodulation method contributes in how the sensors work, so wavelength demodulation is one of the most important techniques to achieve a distributed FBG system.The purpose of this paper is to discuss the demodulation system design and application research of strain and temperature sensing network of the distributed FBG.Firstly, on the basis of the deep researches of domestic and overseas literatures, the mechanism of the optical fiber grating sensors and the categories of FBG were generally introduced. The development trend of FBG sensing and several questions need to be solved in the practical application were summarized.Secondly, this thesis focuses on the basic theoretical and technical researches on the optical fiber grating sensors, including coupled model theory of FBG, and the sensitivity coefficient of strain/ temperature sensor are the most important parts in this article. Then it introduces the demodulation principle of distributed FBG sensors and some methods of FBG multiplexing, sums up the demodulation solutions of distributed FBG sensors and the problems faced now.Thirdly, on the basis of above analysis, a distributed FBG sensor demodulation system based on nom-balanced M-Z interferometer demodula- tion technique was designed. The system can simultaneously realize the demodulation of three channels after the designing of optic-route, electro-circuit, the data acquisition using of DAQ2005 and programming with Lab VIEW software using spectrum analysis.Lastly, a signal simulation phase meter based on Lab VIEW is designed. It uses the signal module instead of the Data Acquisition Module, and design random noise、A / D converter quantization error and so on. It makes the signal dealt with have the same Characteristics such as Acquisition of experimental data signals, and makes the simulation experiment have more research value.更多还原