光纤传感网络中微弱光信号的检测

发布时间：2018-05-27 04:16

本文选题：光纤传感 + 光电探测　；参考：《北京交通大学》2017年硕士论文

【摘要】：光纤传感网络广泛地应用在我们的日常生活当中,在重大工程健康检测、航空航天、安防等领域起着重要的作用。可是由于传感类型繁多,网络庞杂,需要的维护检测成本高,尤其专门的检测设备动辄几十万以上,且存在设备操作复杂、界面不友好、体型庞大、不能移动测量、功能单一等问题,给传感网络的问题定位、排查故障线路等带来诸多问题。基于以上困境,本文对现存的传感网络进行深入研究,研究了光纤传感网络的相关理论和技术特点,区别传感网络的适用测试范围。重点研究了光纤传感网络的光信号接收检测,致力于研究制作出能够检测微弱信号的光电探测器,并使探测器便于携带,易于升级和扩展应用,与其他外设设备组合使用,降低接收成本且能保证探测的可靠性。为了提高便携性,可扩展性,结合市场广泛存在的智能手机作为探测器的后续转换显示设备,将探测器结合手机作为便携式的仪器仪表,用于光纤传感网络微弱信号的检测。本文主要内容及成果有:1、详细论述了便于与手机结合的光电探测模块的设计过程,具体内容包括:探测器的设计原理、光电探测器与手机的接口电路的设计、器件选型、噪声分析、仿真、原理图和印制板图设计、焊接电路板、实验验证等。创新点为:(1)将光探测器检转换的后的电压信号再经电压/频率(V/F)转换的方式输出到手机,结合手机上安装的APP和其自身音频转换模块进行后续处理,并在手机屏幕上显示测量结果。(2)为了扩大检测范围,实现微弱光信号的检查,给探测器增加了自动切换档位的功能。基于此思想,在第二章中设计了一款可以检测低频微弱信号的便携式光功率计,它可应用于光纤传感网络的功率测试。2、在光纤传感系统中,使用的更多的是动态信号的检测,针对动态信号的特点,同样是结合智能手机作为接收终端,设计了一款可以探测动态信号的光电探测器,设计过程包括:原理分析、仿真确定相关参数、原理图和印制板图设计、光电探测器与手机的接口电路的设计和焊接调试。在深入分析光缆识别系统相关原理后,使用该探测器,结合手机制作了一个便携式的光缆识别仪,可用于光缆中不同线路的排查工作。此外,还深入分析了相干检测的原理及相关系统结构,研究如何进一步提升探测的灵敏度。
[Abstract]:Fiber optic sensor network (FSNs) is widely used in our daily life and plays an important role in major engineering health detection, aerospace, security and other fields. However, because of the variety of sensor types, the complex network, the high cost of maintenance and detection, especially the specialized testing equipment, which can easily be used more than several hundred thousand, and the existence of complex equipment operation, unfriendly interface, large size, unable to move measurement, The problem of single function brings many problems to the problem location of sensor network and troubleshooting of fault line. Based on the above difficulties, the existing sensor networks are studied in this paper, the relevant theory and technical characteristics of optical fiber sensor networks are studied, and the applicable testing range of the sensor networks is distinguished. In this paper, the optical signal receiving and detection of optical fiber sensor network is studied emphatically, and the photoelectric detector which can detect weak signal is researched and manufactured, which makes the detector portable, easy to upgrade and expand application, and used in combination with other peripheral equipments. Reduce the cost of receiving and ensure the reliability of detection. In order to improve portability and expansibility, the detector combined with mobile phone is used as portable instrument to detect weak signal in optical fiber sensor network. The main contents and achievements of this paper are as follows: 1. The design process of photoelectric detection module, which is convenient to combine with mobile phone, is discussed in detail, including: the design principle of detector, the design of interface circuit between photodetector and mobile phone, the selection of devices, Noise analysis, simulation, schematic and PCB design, welding circuit board, experimental verification, etc. The innovation point is: 1) output the voltage signal after the photodetector has been checked and converted to the mobile phone through the voltage / frequency V / F conversion mode, combined with the APP installed on the mobile phone and its own audio conversion module for follow-up processing. In order to expand the detection range and realize the detection of weak optical signals, the detector is added the function of automatically switching gears. Based on this idea, a portable optical power meter which can detect low frequency weak signals is designed in the second chapter. It can be applied to the power test of optical fiber sensor network. In the optical fiber sensing system, the detection of dynamic signals is more often used. According to the characteristics of dynamic signal, a photoelectric detector which can detect the dynamic signal is designed, which is also combined with the smart phone as the receiving terminal. The design process includes: principle analysis, simulation and determination of relevant parameters. Schematic diagram and PCB design, optoelectronic detector and mobile phone interface circuit design and welding debugging. After deeply analyzing the related principle of optical cable identification system, a portable optical cable recognition instrument is made by using the detector combined with mobile phone, which can be used to check and check different lines in optical fiber cable. In addition, the principle of coherent detection and the related system structure are analyzed, and how to improve the sensitivity of detection is studied.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN911.23;TN929.11;TP212.9

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