【作者】 范典；

【导师】 姜德生； 何伟；

【作者基本信息】 武汉理工大学 ， 通信与信息系统， 2005， 硕士

【摘要】 传感器有着非常广泛的应用领域,多年来一直是研究热点。光纤光栅传感器可以工作在强电磁场、高温有腐蚀性的以及有爆炸危险性的恶劣环境中,因而比其它传感器有更广阔的应用范围。由于光纤光栅传感器采用数字式测量技术,具有精确度高、稳定性好、不易受外界各种因数的干扰等特点。但目前的光纤光栅传感技术受到系统检测容量过小的限制,不能应用于大型复杂工程的监测使用。同时,由于一个系统中光纤光栅传感探头的数量太少,使单个光纤光栅传感探头的成本太大,这也削弱了光纤光栅传感系统在市场中的竞争力,如果能够增大系统的容量,单个光纤光栅传感探头的成本就会下降,从而使光纤光栅这一先进的传感技术能够得到更广泛的应用。 本课题研制一种编码式光纤光栅传感检测系统,该系统引入多维编码光纤光栅传感复用新方法。在光纤的同一位置,制作两个或者两个以上不同波长的光纤布拉格光栅,称之为编码式光纤光栅。利用编码式光纤光栅的布拉格波长对待测对象的位置和温度、应力、应变等进行编码,当待测对象的环境参量发生变化时,与之对应的编码,即编码式光纤光栅的布拉格波长随之同时同点发生变化,借以提高传感系统的容量,实现对特定对象(如油罐、油气管道、高压变电站等)的温度以及应力、应变等的准分布式定点测量。 编码式光纤光栅能够在增加很少成本的基础上,提供与单光栅相比多数倍的信息量,不仅可以实现利用一个传感器检测多个参量,而且将编码技术引入传感领域,将编码技术与传感技术结合起来。光纤光栅传感技术具有极高的准确性和很好的长期稳定性,但光纤光栅解调设备制造成本很高,限制了光纤光栅传感技术的应用。编码式光纤光栅的制作及其在编码式光纤光栅检测系统中的应用,使其不仅能保持原有优点,而且大幅提高单个系统的检测容量,从而为市场化应用打下坚实的基础。 本文涉及到信息、电学、材料等方面,主要做了以下工作: 1.分析现有的基于光纤光栅的传感复用技术,比较各种技术的容量、串扰等系统性能; 2.设计编码式光纤光栅传感网络,包括制备编码式FBG传感阵列,适用于不同物理量测量的波长解调系统的研究,设计寻址解码程序和通过信息融合技术实现被测物理现象的重构; 3.使用金属化封装技术制备FBG传感器,并通过实验证明其优于以往的传感特性; 4.提出一种适用于高瞬态量测量的双边缘滤波波长解调系统,并通过理论和实验两方面证明其系统性能。更多还原

【Abstract】 Sensors being widely used in the world are always the research hotspot. Fiber Bragg Grating sensors can work in the area of strong electromagnetic field, high temperature, corruptive and explosive bad conditions, therefore have more applications than other sensors. It take digital measurement technology, has the characteristics of high precision, high stability, immune to environmental disturbance of all sorts of factors. However, Fiber Bragg Grating sensing technology in the present has the disadvantage of too small system capability of sensors, this limits its applications in great and complicated engineering. In the same time, that the quantity of sensors in this system is too small makes the cost per sensor too high. It impairs its contest ability in markets. If we can increase the capability of this system, the cost of a single sensor would decrease, so more areas will benefit from its use.This paper study a new kind of encoding Fiber Bragg Grating sensing system, it introduces a new dimensions encoding fiber grating sensing multiplex method, as is to fabricate two or more FBGs with different peak wavelength in the same location of the fiber, called encoding FBG. The Bragg wavelengths of the FBGs are used to encode the temperature , stress , pressure of the environment. As the environment parameters change, the codes which are the Bragg wavelengths of the FBGs accordingly change in the same time and in the same location, so as to increase the system capability, realize the measurement of temperature stress and pressure for special engineering (such as oil tank, power station, tunnel) in a way of distributing measurement.Encoding Fiber Bragg Grating with a few more cost can provide several times of information as single Fiber Bragg Grating. It not only can realize multiple parameter measurement, but also introduce encoding technology into sensing areas, combining the sensing technology and the encoding technology together. Although Fiber Bragg Grating sensing technology has high precision, high stability of long term, the cost of the demodulation equipment is very high. It limits its application. The fabrication of Encoding Fiber Bragg Grating and the implementation in the Encoding Fiber Bragg Grating sensing system makes it not only keep its advantage but also increase the capability of single system, so as to get a strong basement for market application.This paper come down to material , optics , mechanic and electrics, the contributions of this paper are:1. Analyze the existing multiple-sense technology based on FBG and compare the system capability of each technology, such as capacity, cross-talking and so on.2. Design encoding FBG sense network, including producing and preparing FBG sense array, studying wavelength demodulation system which is fit for different physical measurement, compiling decoding program and reconstructing measured physical phenomenon by multi-sensor information fusion technology.3. Use metalized encapsulation technology to prepare FBG sensor, whose sensing character is better than traditional technology testified by experiment.4. Develop double-edged wavelength demodulation system, which is fit for high-speeded shifting measure and prove the system capability in theory and experiment.更多还原