Scheduling schemes for an integrated flight and propulsion control system

We describe two schemes for scheduling an integrated flight and propulsion control system for an experimental vertical/short take-off and landing (V/STOL) aircraft concept in the acceleration from hover (0-120 kn) flight phase. Multivariable integrated flight and propulsion controllers are designed at several points over the V/STOL envelope and implemented as exact plant observers with state feedback. In the first scheduling scheme, the values of the state feedback and observer gain matrices are interpolated between the fixed-point designs as a function of aircraft speed. In the second approach, the control signals produced by the different fixed-point controllers are blended, allow ng a significant reduction in the order of the scheduled controllers. Both scheduling schemes are shown in non-linear simulatior to provide excellent handling qualities as the aircraft accelerates from the hover. (C) 2002 Elsevier Science Ltd. All rights reserved.