A Digital Flight Control System for an Unstable Aircraft

摘要

Digital simulation was used to compute responses of a typical fighter-type aircraft with a digital flight control system to control column and gust excitation. Handling qualities of the aircraft plus control system were evaluated by assessing response to step control column demands against the C* handling qualities criteria. Stable and unstable aircraft configurations were studied. By calculating system closed loop eigenvalues an analysis of the effect on stability of changes in various system gains, sampling rate and aircraft CG position was made. From these results the digital flight control system gains were modified to stabilize an aircraft with a more rearward CG position, while maintaining satisfactory handling qualities.