| Resumo : |
An active flutter suppression control law is developed for a generic flexible aircraft using the linear quadratic regulator synthesis technique with output feedback. An aircraft model readily available was provided in its linearized form around straight and level-flight trimmed conditions for various altitudes, at a constant Mach number of 0.78. An extensive exploration of the vehicle dynamics was held, in order to understand the mechanism of the various aeroelastic modes and thus drive to a better proposal of controller architectures. Three architectures were initially proposed and confronted with the design objectives after their synthesis at an altitude of 20000 ft. One of the architectures surpassed the minimum desired damping ratio and was then tested in various altitudes, showing a damping ratio improvement at neighboring altitudes for the initial flutter mode, but destabilizing other aeroelastic modes. Nevertheless, the flutter clearance envelope was extended, with the first flutter altitude decreased by 6000 ft, thus meeting the objective of postponing flutter occurrence. |