Improving Performance for Nonlinear Aeroelastic Systems via Sliding Mode Controller

Nonlinear aeroelastic system for controlling the problem of flutter and limit cycle oscillatory (LCO) is proposed. The flight dynamic model describes the plunge and pitch motion of the aircraft section wing with leading and trailing edge control surfaces. Aerodynamic and structural nonlinearities interaction leads to instability phenomena such as flutter and LCO on the wing. Sliding mode control law is designed for the aeroelastic model, and its robustness toward suppressing the LCO and avoiding chatter phenomenon are shown. The results of the simulation show the improvement of the performance of the aeroelastic system. The proposed control law effectively removes the LCO problem and regulates the system states pitch and plunge to origin even under the gust disturbance and limited control surface deflection.