Design of a flight control system for a highly maneuverable aircraft using robust dynamic

This paper presents a methodology for the design of flight controllers for aircraft operating over large ranges of angle-of-attack. The methodology is a combination of dynamic inversion and structured singular value (p) synthesis. An inner-loop controller, designed by dynamic inversion, is used to linearize the aircraft dynam­ics. This inner-loop controller lacks guaranteed robustness to uncertainties in the system model and the mea­surements; therefore, a robust, linear outer-loop controller is designed using μ synthesis. This controller minimizes the weighted H_∞ norm of the error between the aircraft response and the specified handling quality model while maximizing robustness to model uncertain­ties and sensor noise. The methodology is applied to the design of a pitch rate command system for longitudinal control of a high performance aircraft. Nonlin­ear simulations demonstrate that the controller satisfies handling quality requirements, provides good tracking of pilot inputs, and exhibits excellent robustness over a wide range of angles-of-attack and Mach number. The linear controller requires no scheduling with flight conditions.