Parametric Approach Of Active Control Technology For Tailless Flying-Wing Aircraft

This thesis investigates ?ight control problems of a heavier than air vehicle withfixed fixed-wing, which is required that this vehicle could ?y in the high altitude insubsonic speed and the active control technology can be realized. The techniques ofrelaxed static stability and active ?utter suppression are involved and safe ?ight tacticsare discussed additionally for these.The ?ying-wing vehicles without horizontal stabilizer and vertical tail are theone body of fuselage and wing. The elevons and split drag rudders are fixed on thetrail edges along the wing outward. Thus, the natural stabilities of longitudinal andlateral directions are deteriorated, even statically unstable. These statically unstable?ying-wing vehicles can't be operated unless the ?y-by-wire control systems havethe function of relaxed static stability, and the longitudinal and lateral stable augmentcontrol system must be applied to realize the technique of relaxed static stability. Thisthesis discusses the lateral control system of the ?ying-wing vehicle. We apply aparametric approach to design the control law of lateral control system, and realizethe maneuver of coordinated turn.As long endurance is required, the ?ying-wing vehicles are generally of largeaspect ratio, or of huge aspect ratio; What's more, as the high altitude is required,the ?ying-wing vehicles adopt ?exible intelligent materials to decrease the weightand increase lift-drag ratio, so these vehicles are in nature of light weight, and aremore ?exible. With the increase of ?exibility and the huge lifting surface, the ?ut-ter phenomenons are prominent which may even destroy the the structure of ?ying-wing vehicles. So the active ?utter suppression is important for safe ?ight. Similarly,an aeroelastic control system of a 3DOF two-dimensional airfoil is proposed in thisthesis. We apply the output suboptimal control method and linear matrix inequalitytechnique to design the robust ?utter suppression control law which can increase the?utter critical speed and realize the technique of active ?utter suppression.