Integrated attitude and morphing control for morphing aircrafts: A method to improve aerodynamic efficiency

This article delves into the study of a morphing aircraft characterized by symmetrically adjustable wingspan and sweep angle, proposing an innovative integrated control method for both attitude and deformation. By establishing a hierarchical structure for control tasks, this method allows the aircraft to prioritize and fulfill attitude control (high-priority task) while allocating any remaining control capability to improve aerodynamic efficiency (low-priority task), without negatively impacting the performance of the high-priority task. Firstly, considering the wingspan and sweep angle as auxiliary control variables, the incremental modeling technique is employed to approximate the nonlinear and uncertain longitudinal model of the morphing aircraft with minimal reliance on pre-existing models. Based on these incremental models, a model predictive control strategy is employed to design the attitude control law, ensuring that the aircraft's angle of attack accurately tracks a reference trajectory while satisfying to any input and state constraints. Secondly, with the goal of maximizing aerodynamic efficiency, a morphing control law is formulated. This law incorporates the dynamic consistency principle to enhance aerodynamic performance while simultaneously fulfilling attitude control requirements, thereby achieving seamless integration of attitude and morphing control. Subsequently, closed-loop stability analysis is conducted for the aforementioned control laws using the practical Lyapunov theorem. Finally, numerical simulations are carried out, demonstrating that the proposed controller exhibits robust performance, minimal model dependency, and a notable improvement in aerodynamic efficiency.