Variable structure flutter control of a prototypical wing section with unsteady aerodynamics

This paper presents a variable structure control system for the realization of an aeroelastic system with unsteady aerodynamics. The aeroelastic model describes the plunge and pitch motion of a wing. Based on the sliding mode design technique, a control law for the trajectory control of the pitch angle is derived. For the synthesis of the controller, only the plunge displacement, pitch angle, control surface deflection and their derivatives are measured, and the states associated with Theodorsen's function are treated as unknown signals. In the closed-loop system, the state vector asymptotically convergers to the origin.