3D shape sensing of flexible morphing wing using fiber Bragg grating sensing method

The 3D shape sensing of flexible morphing wing using fiber Bragg grating (FBG) sensors is presented in this paper. A morphing wing prototype with polyimide thin film skin is constructed, and forty-eight FBG sensors are glued on the skin surface. The calibration experiments of the FBG sensors are conducted to ensure relative accurate conversion between Bragg wavelength shift (BWS) and bending curvature of the polyimide skin. The relation of the BWS values with the airfoil profiles are analyzed. The bending curvatures of the polyimide skin are calculated. The 3D shapes of the polyimide skin at different airfoil profiles are reconstructed. The 3D precise visual measurements are conducted using a digital photogrammetry system, and then the correctness of the shape reconstruction results are verified. The results prove that the maximum error between the 3D visual and FBG measurements is less than 5%, the FBG sensing method is effective for the shape sensing of flexible morphing wing with polyimide skin.