Multifidelity Control of Aeroelastic Systems: an Immersion and Invariance Approach

This paper deals with the active suppression of aerodynamically driven limit-cycle flutters. Because of the significant dependence of such outcomes upon flight conditions, an adaptive solution is selected. The related task is accomplished through an immersion and invariance controller coupled to a sliding-mode observer. To simplify its tuning while satisfying robust stability conditions, the design of the controller includes attenuating linear filters. The effect of using different fidelity approximations for the aerodynamic subsystem is verified on three different test cases, adopting reduced-order models to design their controllers, including the dynamics of sensors and saturating actuators. The resulting active systems are subsequently verified against diverse nonlinear high-fidelity aerodynamics, flight conditions, and structural parameters.