【作者】 林巧；

【导师】 吴兴坤；

【作者基本信息】 浙江大学 ， 光通信技术， 2011， 博士

【摘要】 自物联网被正式列为国家五大新兴战略性产业之一写入政府工作报告之后,传感器在国内的研究再次掀起了一股热潮。光纤传感器由于具有灵敏度高、抗电磁干扰能力强、动态范围大、防水防潮、耐腐蚀、质量轻、体积小、损耗小等优点,成为了研究的热点之一。本文提出了两种类型的光纤传感器：一种是基于光纤法布里-珀罗(Fabry-Perot, F-P)干涉的加速度计；另一种是基于光纤迈克尔逊干涉的弯曲传感器。基于光纤法布里-珀罗干涉的加速度计用固定于圆网状弹性膜片上的硅微反射镜与处理过的光纤端面构成F-P干涉腔,产生了相位差随外界加速度改变的光干涉信号。该传感器采用相位生成载波技术(Phase Generated Carrier, PGC)通过对干涉信号的调制和解调实现了对相位差的精确测定。对该加速度计样机的测试结果表明,该光纤加速度计拥有63.2 rad/g的灵敏度,160 Hz的共振频率,4μg的分辨率及接近108的动态范围。同时,本课题利用已设计好的PGC程序对由光纤带产生的迈克尔逊干涉信号进行调制解调,获得了灵敏度为43.96 rad/m-1且分辨率达0.004 m-1的新型光纤弯曲传感器。本论文从研究光纤传感器的基本理论出发,主要完成了以下几部分的内容：1.深入了解了光纤传感器的相关基础知识,包括光纤的结构、光纤传输光波的原理、光纤传感的基本原理及常用于光纤传感系统中的各种器件。研究了传感器的主要性能指标,为本论文展开光纤传感器的设计方案以及对传感器样机的测试评估奠定了理论基础。2.从加速度计的定义出发,对现有的加速度计设计原理及优缺点作了分析,总结归纳了加速度计的发展方向及趋势。3.详细阐述了各种干涉型光纤加速度计的结构设计和工作原理,提出了一种基于光纤F-P干涉的加速度计。设计了该加速度计的惯性传感结构,用工程软件CosmosWorks分析了惯性传感结构中弹性膜片在不同加速度情况下的应变情况。研究了适用于该加速度计的光干涉信号的PGC技术的实现方法。4.介绍了利用CNC(Computer Numerical Control)精密雕刻技术制作不锈钢圆网状弹性膜片的方法,并测试了惯性传感结构中微反射的位移与加速度的关系。研究了相位生成载波技术的程序算法,实现了对干涉信号精确的调制解调。实验测试了加速度计样机的各种性能,结果表面该加速度计达到了高分辨率、大动态范围的设计目标。5.阐述了几种典型的光纤弯曲传感器的基本原理和应用,提出了一种基于光纤迈克尔逊干涉的弯曲传感器。介绍了光纤带和光纤折射率匹配液动态腔的制作方法和过程,而这两个部件是光纤弯曲传感器的关键结构,是保证光纤弯曲传感器性能的前提。6.实验测试了该光纤弯曲传感器,结果表面其相对于现有的光纤弯曲传感器在分辨率上有较大的提高。更多还原

【Abstract】 Since Internet of Things was listed as one of the five emerging strategic industries written into the government work report, the researches of sensors set off a boom in the country. Because of high sensitivity, anti-electromagnetic interference capability, dynamic range, waterproof, corrosion resistance, light weight, small size and low loss, fiber sensors become one of hot researches.In this thesis, a novel fiber optic accelerometer based on Fabry-Perot interfemetetry and an optical fiber bending sensor based on Michelson interferometry are proposed.The fiber optic accelerometer utilizes a silicon micro-mirror mounted on a mesh spring elastic structure and a fiber facet to form a Fabry-Perot cavity which can generate optical interference signals as a function of acceleration. Phase generated carrier technology(PGC) was adopted to modulate the interference signals to obtain a high resolution of phase signals. Performance measurement of prototype shows it has a sensitivity of 63.2 rad/g below a resonance frequency of 160 Hz and a resolution of 4μg with a dynamic range near 108. And an optical fiber bending sensor obtains a sensitivity of 43.96 rad/m-1 and a resolution of 0.004 m-1, by utilizing PGC to modulate the Michelson interference signals generated by a fiber ribbon which is affixed onto an elastic structure,.From the study of the basic theory of fiber sensors, this thesis mainly completes contents as followings:1. Concentrated on the understanding and study of the basic concept of fiber sensors, including the structure of fiber, the theory of light transmit in fiber and the devices commonly used in fiber sensors. The main parameters ofsensors were also described. All of these provided the theoretical basis of the design of sensors, as well as prototypes testing and evaluation.2. Based on the definition of accelerometers, analyzed both the advantages and disadvantages of various accelerometers. Summarized the trends of accelerometers.3. Described the design and principle of deferent interference fiber optic accelerometers in detail. Proposed a fiber optic accelerometer based on Faby-Perot interfermetry. Design the inertial sensing system of the fiber optic accelerometer and did Strain analysis of the elastic structure of the inertial sensing system by CosmosWorks. Studied the ways to realize phase generated carrier modulation and demodulation of this accelerometer.4. Introduced how to use CNC(Computer Numerical Control) precision engraving technology to fabricate stainless steel mesh and how to implement PGC algorithm. Took tests of the accelerometer, and the results show it achieves both in high accuracy and large dynamic range.5. Described the basic theory and application of several kinds optical fiber bending sensor, and proposed an optical fiber bending sensor based on Michelson interferometry. Introduced the fabrication of the fiber ribbon and fiber index matching liquid cavity, which are the critical components in the optical bending sensor.6. Took experimental tests of the optical fiber bending sensor, measurement results show it has a resolution of 0.004 m-1 which is higher than most of bending sensors.更多还原