Modeling and LQR Control of a Two-Dimensional Airfoil


Shana D. Olds

Master's Thesis submitted to the Faculty of the Virginia Tech in partial fulfillment of the requirements for the degree of

Master of Science




Dr. John A. Burns

April 21, 1997
Blacksburg, Virginia


In this paper we develop a mathematical model of a two-dimensional aeroelastic airfoil. This model is used to design a flutter suppression controller. Flutter is a vibration in a wing caused by airstream energy being absorbed by the lifting surface. Flutter increases with increasing speed. For simplicity, we consider a flat plate in a two-dimensional flow. The model is developed in the frequency domain and then transformed into the time domain. The uncontrolled model is numerically simulated using MATLAB. Linear Quadratic Regulator (LQR) theory is used to design a state feedback controller. The LQR control scheme consists of using a full state feedback controller of the form u=-Kx, where K is a control gain matrix. The goal is to use LQR theory to supress flutter and to maintain stability of the closed loop system.

List of Attached Files

etd.pdf solds.pdf

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