Adaptive Aeroelastic Control of a Supersonic Wing Section with Flap

Abstract

This paper concerns the adaptive control of a nonlinear 2-D wing-flap system operating in supersonic/hypersonic flight speed regimes. A number of issues related to flutter and post-flutter of 2-D supersonic lifting surfaces are addressed in this paper. Among those are: i) investigation of the implications of the non-linear unsteady aerodynamics and structural nonlinearities on the stable/unstable character of the limit cycle, and ii) study of the implications of the incorporation of control capability on both the flutter boundary and the post-flutter behavior. An output feedback control law is implemented and its performance toward suppressing flutter and limit cycle oscillations (LCOs) as well as reducing the vibrational level in the subcritical fl ight speed range is demonstrated. The control law proposed here is applicable to minimum phase systems and we provide conditions for stability of the zero dynamics. The control objective is to design a control strategy to stabilize the pitch angle while adaptively compensating for uncertainties in all the aeroelastic model parameters. It is shown that all the states of the closed-loop system are