A fixed H-infinity controller for a supermaneuverable fighter performing the Herbst maneuver

This paper presents an H-infinity flight control system design case study for a supermaneuverable fighter flying the Herbst maneuver. The Herbst maneuver presents an especially challenging flight control problem because of its large ranges of airspeed, angle of attack and angular rates. A fixed H-infinity controller has been developed via the mixed-sensitivity problem formulation for 20 linearized models representing the maneuver. Both linear and nonlinear full model evaluations indicate that this single H-infinity controller together with a fixed LQR inner loop feedback have achieved 'robust stability' and 'robust performance' for the entire maneuver without gain scheduling.