Quantitative Feedback Theory FCS Design for the Subsonic Envelope of the Vista F-16 Including Configuration Variation

摘要

An aircraft's response to control inputs varies widely throughout its flightenvelope. The aircraft configuration also impacts control response through variations in center of gravity and moments of inertia. Designing a flight control system (FCS) to accommodate the full flight envelope and configuration set of an aircraft is clearly a complex undertaking. Quantitative feedback theory (QFT) is a design tool which enables the engineer to attack this task in an efficient way. Although QFT is a robust control design technique, it is an interactive algorithm allowing the engineer full control over compensator order and gain. In this research effort, a full subsonic flight envelope FCS is designed for the VISTA F-16 aircraft using QFT. Four aircraft configurations are considered. The strict control of the compensator order and gain allowed by QFT facilitates the attainment of desired performance while avoiding physical saturations. In addition, flying qualities are imbedded in the longitudinal design through the use of a control parameter which varies with the aircraft's energy state. This parameter is synthesized to closely reflect the actual control desires of the pilot throughout the aircraft flight envelope. Linear simulations with realistically large control inputs are used to validate the design.