Improved CST Method for Shape Perception of Flexible Variable-Camber Wings

The shape perception and parametric description are prerequisites for the optimization and control of flexible camber-morphing wing surfaces, while traditional Class function/Shape function Transformation (CST) methods are difficult to meet the demand for accurate description of large-scale trailing-edge camber variation. To address this issue, this paper conducts a study on shape perception and high-precision parametric description for wings with fixed leading edge and large trailing-edge camber deformation. A three-segment variable-camber morphing wing configuration is proposed, which adopts concave hexagonal cells combined with sliding skin. And, a segmented CST difference fitting method with C1 continuity constraint is proposed to achieve low-dimensional and high-precision description of complex wing surfaces. Furthermore, a distributed sensing system composed of strain sensor arrays, laser sensor arrays, IMU, and linear displacement sensor is established to achieve shape perception under both static and dynamic wing conditions. Experimental results show that compared with the conventional CST method, the accuracy of the proposed parametric description method has been improved by one order of magnitude, and its representation of large trailing-edge deformation variable-camber wings satisfies the typical wind-tunnel tolerance. The shape sensing system effectively validates the feasibility of real-time application of the proposed method.