FBG形状传感器应变传递与传感性能研究

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. 08 mm. 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.