多芯光纤光栅形状传感性能与重构误差研究  

Research on shape sensing performance and reconstruction error of multi-core fiber grating

作　　者：周勇[1] 胡文彬[1] 程普 叶泓蕤 郭东来 杨明红[1] Zhou Yong;Hu Wenbin;Cheng Pu;Ye Hongrui;Guo Donglai;Yang Minghong(National Engineering Research Center for Optical Fiber Sensing Technology and Network,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学光纤传感技术与网络国家工程研究中心,湖北武汉430070

出　　处：《红外与激光工程》2023年第3期273-281,共9页Infrared and Laser Engineering

基　　金：湖北省技术创新专项重大项目(2018AAA016)。

摘　　要：多芯光纤光栅形状传感技术利用空分复用以及应变监测的优势,结合不同的栅点布设方案,实现待测对象的连续曲率和形状传感。首先介绍了多芯光纤光栅曲率和挠率传感原理,提出采用齐次矩阵变换的三维重构算法实现光纤的三维形状重构。为了探究不同光栅密度对实验精度的影响,利用算法编程模拟了不同光栅间距下的三维形状重构精度,依据模拟仿真的结果,建立了不同光栅间距与三维重构误差之间的关系。三维形状传感实验使用光栅间距为10 cm和5 cm的七芯光纤光栅串。实验结果表明,最大误差出现在尾点处,分别为2.56 cm和1.15 cm,占全长的3.2%和1.4%,平均误差为1.32 cm和0.62 cm,占全长的1.7%和0.8%。实验结果与仿真值比较接近,说明可以依据仿真结果对不同光栅间距下的三维形状误差进行预测。结合具体的应用场景合理配置测点资源,在较低的成本范围内实现高性能的检测。Objective At present,shape sensing technology based on multi-core fiber grating is mainly divided into two categories,one is the optical frequency domain reflectometry(OFDR)demodulation technology based on the all-same weak grating.The other is multi-core grating or integrated grating shape sensing technology based on wavelength demodulation mode,and the multi-core grating array sensing system based on wavelength demodulation mode has the advantages of small size,high signal-to-noise ratio,fast acquisition speed and high real-time demodulation.In view of the diverse shape sensing needs in the actual application,the multi-core grating array multi-core sensing system using wavelength demodulation can be flexibly configured according to the actual needs of the number and spacing of the grating,which can realize the shape monitoring of the measured object with more flexible sensing distance and more diverse shape change span,which has a wider application prospect.However,because the multi-core grating measurement point cannot be continuously in space,the shape of the blank grating area between the measurement points cannot be obtained,and there is a blind zone of the measurement point.In practical applications,in order to improve the accuracy of shape sensing,it is necessary to study the shape deformation characteristics of the object to be measured,and design a reasonable grating distribution configuration scheme under the premise of taking into account the measurable key points and the full range of measurable areas to be measured.Methods Based on the strain sensing characteristics of seven-core fiber gratings,this paper adopts a three-dimensional shape reconstruction method based on homogeneous transformation matrix to reconstruct the shape of two seven-core fiber gratings with different grating spacing,solve the curvature and torsion of the region where the grating measurement point is located by the relative change value of the wavelength of the grating point,and obtain the curvature and torsion of the blank gra

关 键 词：光纤形状传感 多芯光纤 布拉格光栅 数值模拟 光栅间距 

分 类 号：TN253[电子电信—物理电子学]