FBG形状传感器应变传递与传感性能研究

Research on Strain Transmission and Sensing Performance of FBG Shape Sensor

摘要:

为提高光纤布拉格光栅(FBG)形状传感器的形状重建精度,减小光栅点的重建位置误差,设计了一种FBG传感元件结构。通过建立传感元件应变传递力学模型,推导出平均应变传递率表达式,并结合传感元件有限元仿真模型,分析了相关结构参数对传感元件应变传递率的影响,将有限元仿真与理论计算结果进行对比,验证了理论模型的有效性。进而分析了应变传递率对传感系统形状重建精度的影响,得出当光栅点应变传递率保持在90%以上时,光栅点的重建位置误差将保持在0.08mm内。该研究表明,通过合理控制影响参数,可有效提高传感元件应变传递效率,减小传感系统形状重建位置误差,从而提高光纤形状传感器的形状重建定位精度。

Abstract:

In order to improve the shape reconstruction accuracy of fiber Bragg grate (FBG) shape sensor and reduce the reconstruction position error of the grating points, a FBG sensing element structure was designed in this paper. By establishing the strain transfer mechanics model of the sensing element, the expression of the average strain transfer rate was derived. And by combining with the finite element simulation model of the sensing element, the influence of the relevant structural parameters on the strain transfer rate of the sensing element was analyzed. The finite element simulation and theoretical calculation results were compared to verify the validity of the theoretical model. Furthermore, the effect of strain transfer rate on the shape reconstruction accuracy of the sensing system was analyzed, and it was concluded that when the strain transfer rate of the grating points remains above 90%, the reconstruction position error of the grating points will remain within 0.08mm. The study shows that by reasonably controlling the influencing parameters, the strain transmission efficiency of the sensing element can be effectively improved, and the position error of the shape reconstruction of the sensing system can be reduced, thus the positioning accuracy of the shape reconstruction of the optical fiber shape sensor will be improved.