FLIGHT CONTROL FOR MIXED-AMPLITUDE COMMANDS

A longitudinal flight control law is derived that provides desirable p recision aircraft-tracking response for small-amplitude commands and d esirable gross acquisition response for large-amplitude commands. Dyna mic inversion and proportional-plus-integral command compensation prov ide precision attitude-tracking control, and time-optimal control prov ides gross acquisition augmentation. Continuous transition between the control modes, without control power saturation, is accomplished usin g Lyapunov function level sets of the nominal small-amplitude closed-l oop system. The control law directly relates design parameters to the closed-loop characteristic equation and flying qualities transfer func tion parameters. The control strategy is applied to an F-16 aircraft m odel augmented with thrust vectoring. The feedback control law exhibit s satisfactory stability and performance robustness shown through line ar analysis and nonlinear simulation.