This paper presents a Fiber Bragg Grating (FBG)-based torque sensor with high sensitivity and miniature size for MIS instruments and multi-finger hands. The proposed sensor design mainly consists of a torque-sensitive flexure structure and two diagonally arranged optical fibers embedded with FBG sensing elements. An improved hollow hexaform structure with flexible hinges has been utilized to design the torque-sensitive flexure with an excellent linear measurement range and a solid capacity to resist non-torsion loading. Two optical fibers with an FBG inscribed each adopt a two-point gluing configuration with a tightly stretched status, and they are arranged diagonally along the hyperboloid surface. This configuration can obtain improved sensitivity and resolution and avoid the drawbacks of FBG chirping and low repeatability. Finite element modeling (FEM)-enabled simulation has been implemented to perform design optimization for further sensor sensitivity improvement and performance investigation. The prototyped sensor has been calibrated and achieves a high resolution of 0.062N $\cdot $ mm within [−100, 100N $\cdot $ mm] and excellent linearity with a small linearity error of 0.68%. The crosstalk experiments on the bending moment of Mx and My and the axial force have been conducted to validate the anti-interference capacity on the basis of the small values of 0.47%, 0.31%, and 1.78%. The proposed design also supports convenient customization to achieve the adjustable measuring range and torque sensitivity, which has been validated by another sensor version with a resolution of 0.26 $\text{N}\cdot $ mm within [−500, 500N $\cdot $ mm].

中文翻译：

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微型光纤布拉格光栅启用的高灵敏度扭矩传感器的设计和验证

本文提出了一种基于光纤布拉格光栅 (FBG) 的扭矩传感器，具有高灵敏度和微型尺寸，适用于 MIS 仪器和多指手。所提出的传感器设计主要由一个扭矩敏感的挠性结构和两个嵌入 FBG 传感元件的对角线排列的光纤组成。改进的带有柔性铰链的空心六边形结构已被用于设计具有出色线性测量范围和抵抗非扭转载荷的坚固能力的扭矩敏感挠性件。两根内接FBG的光纤采用两点胶合结构，紧绷状态，沿双曲面对角排列。这种配置可以获得更高的灵敏度和分辨率，并避免 FBG 线性调频和低重复性的缺点。已实施支持有限元建模 (FEM) 的仿真，以执行设计优化，以进一步提高传感器灵敏度和性能调查。原型传感器已校准并达到0.062N的高分辨率 $\cdot $ 毫米 [−100, 100N 以内 $\cdot $ mm] 和出色的线性度，线性度误差很小，为 0.68%。以0.47%、0.31%、1.78%的小值为基础，对Mx和My的弯矩和轴向力进行串扰实验，验证了抗干扰能力。所提出的设计还支持方便的定制，以实现可调节的测量范围和扭矩灵敏度，这已被另一个分辨率为 0.26 的传感器版本验证 $\text{N}\cdot $ 毫米 [−500, 500N 以内 $\cdot $ 毫米]。