一种增敏结构的FBG倾角传感器研究

Research of FBG tilt sensor with enhanced sensitivity structure

实现了一种增敏结构的光纤Bragg光栅(FBG)倾角传感器,在传统等强度梁结构的基础上设计一种新型凸台增敏结构,将经预拉伸后的FBG两端的光纤固定于凸台上,刻有光栅部分位于凸台之间,当传感器的倾角状态变化时,摆锤的重力分量迫使梁发生弯曲变形,FBG感知变形应变,中心波长产生漂移,根据波长的漂移情况表征倾角状态。加工制造了无凸台结构和凸台高为0.5mm、1.0mm的3种FBG倾角传感器以开展增敏效果对比,实施了量程、灵敏度、线性、重复性和蠕变等的测试。实验表明,设计的增敏结构可显著提高传感器的灵敏度,凸台高为1.0mm的传感器灵敏度提高了2.23倍,倾角的测量分辨率可达到0.005°,且在重复性、线性、蠕变等方面有着良好的测量能力,证明了基于本文增敏结构的倾角传感器的有效性和可行性。

In this paper,a new fiber Bragg grating（FBG）tilt sensor with enhanced sensitivity structure is proposed,which has a new type of convex table design based on the traditional equal-strength-beam structure.The FBG is fixed on the surface of the convex table after pre-tensing,and the grating part is between the two convex tables.When the sensor′s angle is changed,the gravity component of the pendulum forces the beam to bend,and the FBG can sense the strain.The center wavelength will shift,which can be used to characterize the state of tilt.In this paper,three kinds of fiber grating angle sensors were manufactured,whose convex tables are 0mm,0.5mm and 1mm.Their measuring range,sensitivity,linearity,repeatability and creep are compared.The experimental results show that the enhanced sensitivity structure can improve the sensitivity of the sensor significantly.The sensitivity of the sensor with 1mm convex table is 2.23 times higher than that without convex table,the resolution ratio of the tilt can reach0.005°,and it has good measurement ability in repeatability,linearity and creep.Therefore,the FBG tilt sensor with enhanced sensitivity structure has good effectiveness and feasibility.