【作者】 袁军国；

【导师】 刘德明；

【作者基本信息】 华中科技大学 ， 光学工程， 2006， 博士

【摘要】 光纤传感器经历了近20年的发展,取得了引人注目的成就,在军事,工业,科研等领域发挥了巨大的作用。其具备了灵敏度高、动态范围大、不受电磁干扰等突出的优点。在包括强度、频率、波长、偏振调制等多种光纤传感形式当中,相位调制型具有最高的灵敏度,而分布式干涉型光纤振动传感器则可以实现连续高精度定位传感,具备广阔的应用前景。本论文从应用的角度对分布式干涉型光纤振动传感器技术中的一些基础问题进行研究了探讨。论文由以下6个部分组成:(1)管道检测技术的现状与发展趋势。(2)不同分布式光纤传感之间的原理对比以及理论分析。(3)干涉型分布式光纤振动传感器中光源的驱动设计。(4)从理论和实验两个方面对分布式干涉型光纤振动传感器的信号解调处理进行分析和探讨。(5)分布式光纤传感器信号检测以及数据采集系统的研究。(6)结束语。论文的第一部分是在参阅其他文献的基础上,对管道检测技术的现状和发展趋势作一个一般性的总结。论文的第二部分对分布式光纤传感器的原理分析作一简单的说明后,重点研究了分布式干涉型光纤振动传感器中的一些关键技术问题。论文的第三部分从分布式干涉型光纤振动传感器对光源的要求出发,采用了高稳定度的恒温控制以及功率稳恒控制方法,通过高信噪比的运算放大器,半导体制冷器,设计了一种激光电源驱动系统,并进行了理论分析和实验验证。结果表明,本系统不仅结构简单,而且温度控制稳定、准确度高。可使半导体激光器的输出波长保持稳定,保证了干涉型光纤传感器的测量准确度。论文的第四部分从理论上推导分析干涉型光纤振动传感器信号调制和解调原理。指出解调的必要性和目前常用的解调方法,设计信号解调方案,根据实验说明3×3耦合器解调方法的特点。由此分别介绍讨论了Labview软件相位解调的方法和效果。论文的第五部分着重研究讨论数据处理系统的实现方法,给出了以高性能数字信号处理器(DSP)、可编程逻辑器件(CPLD)和USB2.0接口为基础的硬件实现框架,并详细介绍了硬件实现的各个组成部分,包括芯片选用、电路连接和软件编程等,以此硬件平台为基础,实现了输出光功率检测子系统的数据处理。在论文的最后,根据实验结果及相应的理论分析,对整个研究作了一简单的总结。更多还原

【Abstract】 Optical fibre sensing technology has been expanding rapidly in the latest decades, and is playing an important role in the area of military, industry and scientific research. It possessed the outstanding advantages based on its high sensitivity, widely dynamic range and immunity to electromagnetic interference. In various kinds of fiber sensor including intensity, frequency, wavelength and polarization modulation, the optical fiber interferometer sensor had the most sensitive. Moreover, the distributed optical fiber interferometer vibration sensor could achieve continuous and high sensitive detecting and locating of the vibration signals, so it has the broad application prospect. This paper conducted research and discussion on several fundmental problems of optical fibre sensing. The paper is composed of 7 parts as listed below:(1) Introduction.(2) The status and trends of real-time monitoring system for pipeline leakage. The simple explanation of distributed optical fiber sensor.(3) The design for accurately controlling output and frequency of the laser diode was invented in interferometic optical fibre sensing.(4) The modulation and demodulation theory of the optical fiber interferometer sensor had been deduced through theoretical and experimental analysis.(5) Research on detection and signal processing system of optical fiber sensor.(6) Conclusion.In the first part, the project was introduced simply from background and task. In the second part, on the basis of referneces, the author gave an overview of status and trends of real-time monitoring system for pipeline leakage. In the third part, after a simple explanation of Optical fiber sensor, emphasis was given on research of important technology of distributed optical fiber interferometer sensor. In the fourth part, through theoretical and experimental analysis, the operation amplifier with high S/N, and a semiconductor cooler were used. A laser power driving system was invented. The experimental data indicate the method is not only simple, but also highly accurate and stable in terms of temperature control. The application maintains the output wavelength of the laser diode at a constant level and assures the measure accuracy in optical fiber interferometer sensor (OFIS). In the fifth part of the paper, the modulation and demodulation theory of the optical fiber interferometer sensor had been deduced and analyzed. Designed the scheme of signal demodulation, and illuminated the characteristic of 3×3 couplers demodulation method by this experiment. Introduced and discussed the effects of the phase demodulation methods using the Labview software. In the sixth part, the author had paid much concern on the hardware realization of the data processing system, which consists of high performance DSP chips, CPLD and USB2.0 interface. Also, each part of the realization is introduced particularly, including chip choosing, circuit connecting and the software program. On the basis of the hardware platform, the author realized signal processing of the child system of output optical power detection. At the end of this paper, a roughly conclusion was given based on the experimental result and corresponding theoretical analysis.更多还原