An engine limiting and anti-windup scheme for a partitioned integrated flight and propulsion control system

Abstract

This paper describes the design of an engine limiting scheme for an integrated flight and propulsion control (IFPC) system for an experimental short take-off and vertical landing aircraft configuration. The scheme is developed to guarantee that specified limits on safety-critic al engine variables are not violated in the event of aggressive pilot demands, and is implemented on a partitioned IFPC system. The structure of the partitioned system comprises a higher level airframe sub controller, a lower level engine sub controller and an interface sub controller. A multi variable input conditioning scheme is also designed in order to avoid problems associated with integrator windup if (a) the actuators reach position or rate limits or (b) the engine protection scheme implements an artificial position limit on an actuator. Successful operation of the safety-limiting scheme for the IFPC system is demonstrated in nonlinear simulation. LPSM low pressure compressor surge margin