【作者】 刁春暖；

【导师】 赵立民；

【作者基本信息】 沈阳工业大学 ， 检测技术与自动化装置， 2008， 硕士

【摘要】 光纤布喇格(Bragg)光栅(FBG)是国际上新兴的一种在光纤通讯、光纤传感等光电子处理领域有着广泛应用前景的基础性光纤器件。当前FBG的制作与应用研究成为世界各国光纤技术研究的热点和重点。作为传感元件,光纤光栅将被感测信息转化为其反射波长的移动,即波长编码,因而不受光源功率波动和系统损耗的影响,另外,光纤光栅具有可靠性好、抗电磁干扰、抗腐蚀等特点,易于将多个光纤光栅串联在一根光纤上构成光纤光栅阵列,实现分布式传感,这是其他传感元件所不及的。FBG传感器的关键就在于精确的检测布喇格反射波长的微小移动,即对波长编码信号进行解调,利用高精度的光谱分析仪可以达到这一目的,但由于其体积庞大,价格昂贵,很难用于实际应用中。开发出高精度、低成本的FBG解调器是将FBG传感器产业化的关键。目前国内不少部门和研究单位对其解调技术进行了很多研究,但是大多数处于实验室研究阶段,离实用化,工程化,产品化的标准还有相当距离。本文提出了一种基于匹配光纤光栅扫描滤波解调的光纤光栅解调方案,利用单片机控制步进电机对匹配光栅施加压力和拉力从而与传感光栅匹配,达到对温度、应变等传感信号的解调。具体的研究内容如下:介绍了光纤光栅的基本机理,主要特性,系统研究了光纤光栅传感原理。对现有的光纤光栅解调方案进行了分析和比较,提出了新的解调方案:即采用基于悬臂梁的匹配法光纤光栅解调系统来对传感信号进行解调。对构成解调系统的硬件和软件进行了设计和分析。并应用此方案完成了应力传感解调实验,就实验结果进行处理和分析,验证所提出的光纤光栅解调方案的可行性,并在实验结果的基础上总结本系统的优缺点,并提出了改进意见。更多还原

【Abstract】 Fiber Bragg Grating (FBG) is a kind of fiber optic device which is expected to be of great prospect of application in fiber communication. Nowadays the manufacturing and application research on FBG has gone into a popular field of the fiber optics technology. As sensor, FBG can be immune from light source disturbance and system loss by transforming sensing information into its reflecting wavelength shift. Besides, FBG is very reliable and also immune from electromagnetic signals and corruption .Many FBGs can be put together on a single fiber to construct a FBG network to build a distributed sensing system. Such a system has shown the unexampled merit shift of Bragg reflecting wavelength precisely, and this is called demodulating of the coded wavelength signals. Though, the OSA can be used to do the measurement, it can not be applied to practical industry situation because of its huge-size and high-cost. Therefore, developing high-resolution and low-cost FBG demodulator is the key issue when it comes to FBG sensors industrializations. Although a large number of researchers in domestic research units have been done a lot of research and investigations on the demodulation of FBG sensor, most of the requirements of mass practical industrial productions.A new FBG demodulation scheme based on tuning matching fiber grating to interrogate the sensing grating is proposed in this paper. To achieve the demodulation of temperature and strain sensing signals, matching FBG’s wavelength is changed by step motor which controlled by computer. Our main research work is as follows:The basic mechanism and main characteristic of fiber bragg grating are introduced. Fiber bragg grating sensor principle is researched in system. Compare and analyze fiber bragg grating demodulate programs in hand. In according with the problem in fiber bragg grating sensor practical application bring up new demodulate program: use matching fiber bragg grating demodulate program on the basis of cantilever demodulate sensor signal. Design and analyze the computer hardware of demodulate system. Using this program have finished physics stress sense demodulate experiment, analyse the result of experimentation, to test and verify the feasibility of fiber bragg grating demodulate program. Base on the result of experiment to sum up the advantage and disadvantage of this system and propose the improving method.更多还原