AUTOPILOT DESIGN USING MIXED H-2 AND H-INFINITY OPTIMAL-CONTROL

An autopilot for a transport aircraft is designed using mixed H-2 and H(infinity) optimal control. The control law design technique allows real parameter uncertainty to be accounted for in the design process. The autopilot consists of an inner loop that controls aircraft heading in response to external commands and an outer loop that tracks a localizer beam so that the aircraft is properly aligned with the runway for landing. The problem formulation and the robust control law design technique allow a wide range of performance and robustness requirements to be met. Analysis of the closed-loop system shows the controller performance and robustness for a number of flight conditions through two separate approach profiles.