Robust control of gust-induced vibration of highly flexible aircraft

This paper mainly addresses the gust suppression and alleviation of highly flexible aircraft using the model predictive controller (MPC) based on linear parameter-varying (LPV) models. The dynamic behavior of highly flexible aircraft is modeled by a coupled nonlinear aeroelastic and flight dynamic formulation. Conventional trailing-edge flaps along the main wings and tails are deployed to provide the required loads for the wing vibration control and/or longitudinal flight attitude control of the slender vehicle. The coupled dynamic equations are performed with linearization and model reduction about a series of nonlinear equilibria to derive reduced-order LPV models. This work considers two quantities as the scheduling parameters in building the LPV models: the gust-induced angle of attack and the modal magnitude of wing deformation. With the reduced-order LPV model, MPC is designed to minimize the wing vibration and rigid-body motions excited by the time-domain Dryden gust perturbation. The proposed LPV modeling is capable of describing large wing deformations, and the LPV-MPC innovatively previews the scheduling parameter and gust disturbance in the prediction horizon. The closed-loop flight responses of a highly flexible aircraft with gust disturbance are presented in the numerical studies, which demonstrate the effectiveness of controlling coupled vibrations and rigid-body dynamics of such slender vehicles.