Adaptive output feedback control of an aeroelastic system with unstructured uncertainties

This paper presents an adaptive control system for the trajectory control a nti stabilization of an aeroelastic system with unstructured model uncertai nties using output feedback, The equations of motion of the chosen aeroelas tic system describe the plunge and pitch motion of a structurally nonlinear wing section. a single trailing-edge nap is used for the purpose of contro l, For feedback only the pitch angle or the plunge displacement is measured . Unlike the linearly parameterized adaptive systems, in this study the str ucture of model uncertainties is unknown. Adaptive control laws for the tra jectory control of the pitch angle and the plunge displacement are derived, The controller has the structure of an inverse (a feedback linearizing) ce ntral system. But the unknown function in the inverse control lan arising f rom the uncertainties in the model is compensated using its estimate constr ucted by a high-gain observer. Simulation results are presented, which show that in the closed-loop system trajectory control of the selected output ( pitch angle or plunge displacement) is accomplished and the state vector co nverges to zero. Furthermore, it is observed that stability and trajectory tracking are preserved in the presence of measurement noise.