Integrating Fly-by-Wire Controls with Perspective Flight-Path Displays

Abstract

To further improve the pilot manual tracking performance and to reduce workload while operating with a perspective flight-path display, the approach has generally been to augment the display with guidance symbology such as a flight-path predictor. An alternative approach would be to augment the controls. That is, through the use of fly-by-wire control technology, the aircraft flight controls can be tailored in such a way that they become compatible with the display. The design and experimental evaluation of two flight control systems to be used in conjunction with a perspective flight-path display are discussed. The first system aims at automating the innermost loop of the aircraft attitude, attitude-oriented fly by wire. The second system aims at automating the aircraft middle loop of flight path as well, namely, flight-path-oriented fly by wire. Both of the designs are evaluated in two pilot-in-the-loop experiments, one conducted in a fixed-base simulator and one in a moving-base flight simulator. These experiments confirm that control augmentation can reduce pilot workload considerably, while at the same time improving path-following performance. The flight-path oriented control augmentation outperforms the other design, with superior path-following performance achieved with the lowest pilot control activity and workload. The benefits of the flight-path-oriented flight control systems become more apparent when the difficulty of the pilot task increases.