BOTDR分布式光纤传感系统多峰谱特征提取技术研究

发布时间：2018-05-28 15:03

本文选题：分布式光纤传感 + Brillouin散射　；参考：《燕山大学》2015年硕士论文

【摘要】：分布式光纤传感技术可以在连续空间与时间上对光纤沿路路径的被测量信息进行实时监测,具有广阔的发展前景。而基于Brillouin散射的分布式光纤传感技术因其具有测量精度高、传感距离长以及实时性好等特点,已成为光纤传感领域的主流技术。本文针对Brillouin分布式光纤传感系统在空间分辨率及测量精度方面存在的问题展开研究。具体如下:首先,本文简单阐述了光纤中散射的种类,论述了光纤中自发和受激Brillouin散射光的产生机理,研究了Brillouin散射谱参数与温度和应力变化之间的响应特性及定量关系,分析了Brillouin散射信号检测技术的分类及其特点,并对布里渊光时域反射(BOTDR)系统的主要性能进行了介绍。其次,针对多峰Brillouin散射谱中心频移高精度及多特征的提取要求,本文提出了一种新的多峰Brillouin散射谱拟合算法,即MCDM-PSO-LM算法,该算法利用多准则决策的原理与性质,准确定位了多峰Brillouin散射谱各个波峰的位置,再对各个波峰分别进行拟合,最终得到了多峰Brillouin散射谱的完整谱线,仿真分析表明该算法能够有效提高系统的空间分辨率。再次,本文介绍了D-S证据理论的基本概念及其组合规则,在此基础上提出了一种新的D-S证据理论组合规则,该规则可以对多峰Brillouin散射谱特征提取算法进行验证与优化,最终得到各个Brillouin散射谱波峰中心频移的准确值,提高了BOTDR系统的测量精度。最后,简单介绍了系统的整体结构,重点介绍了系统中的几个重要模块的参数及其在系统中的作用,得到了实验条件下的多峰Brillouin散射谱,并利用MCDM-PSO-LM算法对实验数据进行拟合,得到了非常理想的结果。
[Abstract]:Distributed optical fiber sensing technology can real-time monitor the measured information along the path of optical fiber in continuous space and time, which has a broad development prospect. The distributed optical fiber sensing technology based on Brillouin scattering has become the mainstream technology in the field of optical fiber sensing because of its high measuring precision, long sensing distance and good real-time. In this paper, the spatial resolution and measurement accuracy of Brillouin distributed optical fiber sensor system are studied. The main contents are as follows: firstly, the types of scattering in optical fiber are briefly described, the mechanism of spontaneous and stimulated Brillouin scattering light in optical fiber is discussed, and the response characteristics and quantitative relationship between the parameters of Brillouin scattering spectrum and temperature and stress changes are studied. The classification and characteristics of Brillouin scattering signal detection technology are analyzed, and the main performance of Brillouin optical time domain reflectance (BOTDR) system is introduced. Secondly, a new multi-peak Brillouin scattering spectrum fitting algorithm, that is, MCDM-PSO-LM algorithm, is proposed, which utilizes the principle and properties of multi-criteria decision making, aiming at the high accuracy of center frequency shift of multi-peak Brillouin scattering spectrum and the requirement of extracting multi-feature. The location of each peak of the multi-peak Brillouin scattering spectrum is accurately located, and each peak is fitted separately. Finally, the complete spectral lines of the multi-peak Brillouin scattering spectrum are obtained. The simulation results show that the algorithm can effectively improve the spatial resolution of the system. Thirdly, this paper introduces the basic concept of D-S evidence theory and its combination rules. On this basis, a new D-S evidence theory combination rule is proposed, which can be used to verify and optimize the multi-peak Brillouin scattering spectrum feature extraction algorithm. Finally, the accurate values of the center frequency shift of each Brillouin scattering peak are obtained, and the measurement accuracy of the BOTDR system is improved. Finally, the whole structure of the system is briefly introduced, the parameters of several important modules in the system and their functions in the system are emphatically introduced, and the multi-peak Brillouin scattering spectra under experimental conditions are obtained, and the experimental data are fitted by using the MCDM-PSO-LM algorithm. Very ideal results have been obtained.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN253

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