Adaptive control with feedback linearization of hysteresis nonlinear aeroelasticity

The question of active flutter control of prototypical aeroelastic wing section in subsonic uncompressible flow is investigated. The dynamic equations of a two-dimensional airfoil with control surface are described in state space. Then based on Lie derivative, the partial input/output feedback linearization was obtained. Suppose that there is parametric uncertainty in the hysteresis nonlinear model, Lyapunov function was used to design an adaptive control law. The simulation results show that the unstable aeroelastic system exhibit limit circle oscillation while the closed loop system, including the adaptive control law, become stable. It should be emphasized that the control law can be used only when the internal dynamics is stable. Even if there is a hard constraint on the control input, satisfactory responses can be achieved.