Incremental sliding mode control of aerodynamics-driven morphing adapting to rapid time-varying aerodynamic characteristics

Monoplane-Biplane Morphing (MBM) aircraft switch between monoplane and biplane configurations by deflecting their ailerons to generate the necessary aerodynamic forces. The control algorithm determines the required lift and moment based on the morphing motion and allocates these demands into the corresponding aileron deflections to regulate the morphing. However, the aerodynamic characteristics of MBM aircraft undergo rapid and significant variations during morphing, necessitating much larger aileron deflections for trim compared to conventional aircraft. These challenges are further compounded when the aircraft features an unsymmetrical trapezoidal wing, as opposed to the rectangular wing configuration examined in our previous work. The resulting aerodynamic behavior is more complex, making it difficult to establish an accurate mapping between aerodynamic forces/moments and control surface deflections. To address this trim problem, this paper proposes an approach that incorporates high-order morphing motion information into an Incremental Sliding Mode Control (ISMC) framework.