差动式光纤双向扭角传感器

Fiber-optic bidirectional torsional angle sensor with differential type

设计了一种新颖的光纤扭角传感器。将两个与尼龙线绞合形成且参数完全相同的光纤段以相反的绕向缠紧在扭轴上，借助它们所产生的微弯损耗随扭角呈差动变化的关系实现检测。基于扭转理论和光纤微弯损耗理论，深入阐述了传感检测机制，并进行了数值仿真。利用PVC模拟扭轴制备了实物装置且进行了相关实验测试。结果表明：在-70—70度角的变化范围内，它能实现双向检测而且正反向响应一致，线性拟合灵敏度为0．0081dB／（m·degree）。鉴于其所具有的特点，此种传感器在扭角检测的相关领域将具有特殊的应用前景。

A new kind of fiber-optic torsional angle sensor was designed. Two same parameter fiber segments were twisted with nylon line and winded on the torsion shaft by the opposite direction, and then microbend losses of two fiber segments were a differential variation when torsional angle was changed. Based on the before-mentioned relationship, the detection function was achieved. Based on theories of torsion and fiber-optic microbend loss, its sensing mechanism was further expounded and the numerical simulation was carried out. The physical device was prepared by using PVC as torsion shaft and experimental tests were carried out. Experimental results show that the sensor could realize bidirectional detection with a consistent response and had a linear fitting sensitivity of 0. 0081 dB/（ m· degree） in the range of -70 - 70 degree angle. Due to its characteristics, the sensor will have the special application prospect in the related fields about torsional angle detection.