Tools and Methods Toward the Advancement of Flight Control for Flexible Aircraft

Abstract

Flight control of a flexible aircraft is a challenge that has become increasingly relevant over the last several decades. For the large twin-aisle commercial aircraft of today, automatic flight control systems are tasked not only with the traditional obligations of safe and stable flight with agreeable handling qualities for pilots, but are now additionally tasked with the mitigation of structural excursions (where objectives include load alleviation from disturbances including atmospheric turbulence and commanded maneuvers), as well as structural modal suppression (for improving ride quality and decreasing airframe fatigue), and may soon be responsible for the active suppression of aeroelastic flutter. These challenges strain or break the suitability of traditional system design and remedy-driven research efforts have been hampered by the scarcity of dynamics models in the public-domain as well as the cost, complexity, and delicate nature of corresponding experimental test beds. With regard to analysis, the multi-controller system architecture is a natural approach to many of the challenges described. In this work we investigate the robustness of stability guarantees for multi-controller systems via the switched system framework and quadratic common Lyapunov function. With regard to model scarcity, we present the development of the Generic Wide Body aircraft model and its simulation and evaluation environment. Finally, with regard to experimental cost and complexity, we present the development, fabrication, and validation of a low cost aeroelastic test bed.