Linear fractional transformation control of the F-14 aircraft lateral-directional axis during powered approach landing

Presents the design of a linear fractional transformation (LFT) gain-scheduled controller, scheduled on angle-of-attack, for the F-14 aircraft lateral-directional axis. The controller is designed for the powered approach flight envelope during which angle-of-attack/airspeed variations range from 2 degrees/182 knots to 14 degrees/126 knots. A linear fractional model of the lateral dynamics is constructed based on four linearized models that correspond to 2,6,10.5, and 14 degrees angle-of-attack. The resulting LFT controller performs well when implemented in a Simulink nonlinear simulation of the F-14 aircraft.