Theta-D Controller-Filter for Aeroelastic Flutter Suppression

Alternative Title

θ-D controller-filter for aeroelastic flutter suppression


A new suboptimal nonlinear filter-based feedback control technique for the suppression of aeroelastic flutter is presented in this study. Novelty of this work lies in utilizing a new technique, called the theta-D method for both the controller and the filter formulations. The theta-D method is synthesized by adding perturbations to a typical optimal control formulation with a quadratic cost function. The controller expressions are obtained by getting an approximate solution to the Hamilton-Jacobi-Bellman (HJB) equation. In many applications, an estimation technique is needed for use in the controller feedback since all the system states are usually not available for measurements. By using the dual nature of controllers and filters, a steady state theta-D filter expression is used for the filter dynamics. A controller using this new method has been designed to suppress the aeroelastic flutter of an airfoil using a filter-based feedback design. Simulation results show that the theta-D filter based controller successfully suppresses any aeroelastic flutter over a range of initial conditions and parameter variations.

Meeting Name

AIAA Atmospheric Flight Mechanics Conference and Exhibit (2004: Aug. 16-19, Providence, RI)


Mechanical and Aerospace Engineering

Keywords and Phrases

Bellman Theory; Hamilton-Jacobi Equation; Perturbation Theory; Control Systems Design; Feedback Control; Nonlinear Filters; Optimal Control; Vibration Damping

Document Type

Article - Conference proceedings

Document Version


File Type





© 2004 American Institute of Aeronautics and Astronautics (AIAA), All rights reserved.

Publication Date

19 Aug 2004

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