Design of adaptive flight control system for aircraft with center of gravity variations

Due to the center of gravity varying over a specific range, the aircraft may deviate from its known dynamics, thus bringing special problems to the attitude control system. To overcome the limitation of accurate mathematical model and poor robust performance of conventional methods, a new design approach of adaptive flight control system for aircraft with center of gravity variations was proposed. The base control law was designed based on inverse dynamics and center of gravity estimation. Then the adaptive sliding mode control module was introduced, in which the sliding mode control could guarantee the robustness and stability of closed loop system, and the adaptive module was designed to compensate model uncertainties and estimation error. The stability of closed loop was proved using Lyapunov stability theory. Simulation results demonstrate that the proposed method compensates uncertainties effectively, and its robust performance is also excellent.