Spatial shape reconstruction using orthogonal fiber Bragg grating sensor array

With distributed orthogonal fiber Bragg grating (FBG) sensor arrays used as modular detection units, an implementation method for deformation detection and spatial shape reconstruction of a frame model structure was proposed in this paper. After brief introduction of curvature detection principle of FBG sensor, the design, fabrication and encapsulation of the FBG modular detection unit were illustrated detailedly. Every unit was composed of four optical fibers, each containing an array of FBG strain sensors. In addition, the method and procedure of the reconstruction algorithm of three dimensional spatial curve based on orthogonal curvature were also described in detail, as well as discrete curvature continuity method. The constructed algorithm was applied to reconstruction the vibration deformation of the experimental frame model, in which four FBG modular detection units were embedded. Afterward, experimental test and verification were performed for static bending and dynamic excitation of the frame model structure, using the developed experiment system. And experimental results verified the feasibility and effectiveness of deformation detection and spatial shape reconstruction based on orthogonal FBG sensor array. Moreover, the results indicated that the proposed method can provide useful research thinking for the further study of active monitoring of flexible space structures.