Design and Piloted Simulator Evaluation of Adaptive Safe Flight Envelope Protection Algorithm

Abstract

This paper discusses the design and evaluation of an efficient safe flight envelope protection method, for keeping a closed loop aircraft with manual control laws within the safe envelope bounds. This flight envelope is estimated adaptively, so that configuration changes and possible impairment can be taken into account. The updated information of the safe envelope is used in the flight control laws to prevent loss of control in flight. It has been found that a control architecture involving separate pilot command filtering is particularly well suited to incorporate these adaptive protections. Moreover, haptic feedback to the pilot controls can be included as well, based on the same adaptive bounds. This has the potential to further increase the flight crew awareness about the risk of losing control in flight. These algorithms have been evaluated in the Simona Research Simulator at Delft University of Technology, to investigate the impact on the awareness of the crew. Commercial airline crews flew multiple challenging approach and landing scenarios in a relevant environment. Results show that the algorithms support the flight crew significantly. They contribute to ’care-free’ flying and to avoiding loss of control in flight.