NONLINEAR, ADAPTIVE CONTROL OF AN AEROELASTIC SYSTEM VIA GEOMETRIC METHODS

A nonlinear control problem for suppressing flutter in a typical wing section with torsional nonlinearity is investigated. Based on earlier results by the authors, Lie algebraic partial feedback linearization is utilized for the construction of a nominal feedback controller. An adaptive method is used to augment the partial feedback linearization to ensure the stability of the closed-loop system under the presence of uncertainties in structural parameters of the aeroelastic model. The closed-loop system is guaranteed to be stable via the application of La Salle's invariance principle. Although the adaptive controller derived in this paper is based on a simple quasi-steady aerodynamic model, numerical experiments show that it also is stable for a full unsteady aerodynamic model.

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