Nonlinear Model Reduction for Aeroelastic Control of Flexible Aircraft Described by Large Finite-Element Models

Abstract

We describe a reduced-modal approach to modelling the nonlinear aeroservoelastic response of a flexible air vehicle, in which the geometrically-nonlinear structural response is characterised by a modal intrinsic form of the equations of motion. We use modal projections of sectional inertial velocities and stress resultants as primary degrees of freedom with the modes obtained from a condensation process by which a large aeroelastic model of the full vehicle is reduced into a nonlinear beam-type modal description. The 2-D aerodynamic model and any additional forces are subsequently projected onto the same set of modes, finally resulting in a set of equations with no nonlinear couplings of order higher than two. We validate this approach using a flying-wing configuration for which published data are available.

Aeroelastic and Trajectory Control of High Altitude Long Endurance Aircraft

“…In this section, we give a brief introduction on the very flexible flying wing model and its reduced-order description based on [5,28].…”

“…Aeroelastic control of this flying wing has been investigated in [28]. We now further enhance its performance in conjunction with the design of trajectory control.…”

Model-Predictive Control of Flexible Aircraft Dynamics using Nonlinear Reduced-Order Models

“…The details regarding the derivation of this coupled system can be found in, 2 and results in an aeroelastic system that is written aṡ…”

Loop-Separation Control for Very Flexible Aircraft

“…Numerical results showed that both the full state and the reduced-order controller were capable of stabilizing the nonlinear full model of the aircraft. Simpson et al [17] and Wang et al [18] took advantage of ROMs to design a controller for gust alleviation. A robust control approach showed a reduction of the maximum root wing bending.…”