关键词: 多芯光纤光栅, 三维变形, 柔性蒙皮, 飞行器, 重构算法

Abstract:  Large-scale deformation monitoring of allomorphic aircrafts in the flight processes was a research difficulty and hot spot in the aerospace field， and the existing methods were difficult to achieve high-precision three-dimensional deformation monitoring during the flight of the aircrafts. Aiming at this problem， a flexible skin-shaped fiber reconstruction method for a variant aircraft was proposed based on optical fiber sensing to achieve deformation monitoring during flight of the aircrafts. Based on the principle of fiber grating strain sensing， the relationship between fiber strain and curvature was derived， the conversion matrix between the local coordinate system and the global coordinate system of optical fiber sensing was established， the conversion of fiber measurement point coordinates to the global coordinate system was realized， and the three-dimensional deformation reconstruction algorithm was studied based on curve fitting according to the spatial curve fitting method. At the same time， in order to reduce the measurement errors of the fiber optic sensors， the calibration tests of the fiber optic sensors were carried out to obtain the strain sensitivity of the sensors. In order to verify the effectiveness of the proposed method， the three-dimensional deformation reconstruction of flexible skin samples under different curvatures was tested experimentally. Experimental results show that the average error of the shape reconstruction method is as 3.5% and the minimum error is less than 2.1% in the deformation ranges of 0～15.38 m-1 curvature of flexible skin samples. The proposed method has a good application prospect in aerospace and other fields. 

Key words:  , multicore fiber grating, three-dimensional deformation, flexible skin, aircraft, refactoring algorithm