This article addresses the analysis and design of a high-resolution and temperature-insensitive inclination sensor using fiber Bragg grating (FBG). The sensor uses a pendulum-based structure with FBG attached to its cantilever arm. Initially, strain analysis of the proposed inclination sensor is carried out using the finite-element method (FEM) to optimize the structure and materials for its fabrication. Experimental analysis is carried out on the inclination sensors by varying the inclination angle, and its results are compared with the FEM-based results. The shift in Bragg wavelength of FBG due to the generated strain at the cantilever arm is observed on optical interrogator. To measure the subpicometer wavelength shift with enhanced resolution and lower uncertainty, eigen decomposition of the reflection spectrum using Karhunen–Loève transform (KLT) is implemented. The range of measurement of tilt angle is found to be 0°–3° with a resolution of 0.0008°. The satisfactory linearity of the measured angle versus true angle, excellent repeatability, and very high resolution validates the feasibility of the proposed inclination sensor.

中文翻译：

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使用反射光谱特征分解的高分辨率基于 FBG 的倾角传感器

本文介绍了使用光纤布拉格光栅 (FBG) 的高分辨率和温度不敏感倾角传感器的分析和设计。该传感器使用基于摆锤的结构，其悬臂上附有 FBG。最初，使用有限元方法 (FEM) 对所提出的倾角传感器进行应变分析，以优化其制造的结构和材料。通过改变倾角对倾角传感器进行实验分析，并将其结果与基于有限元法的结果进行比较。在光学询问器上观察到由于悬臂上产生的应变引起的 FBG 布拉格波长的偏移。为了以更高的分辨率和更低的不确定性测量亚皮米波长偏移，使用 Karhunen-Loève 变换 (KLT) 实现反射光谱的特征分解。发现倾斜角的测量范围为0°–3°，分辨率为0.0008°。测量角度与真实角度的令人满意的线性度、出色的重复性和非常高的分辨率验证了所提出的倾角传感器的可行性。