An Application of LQR Theory in an Integrated Guidance-Control Design for Advanced Cruise Missiles

Modern Control theory and estimation techniques have been studied in connection with missile guidance, with results indicating vast improvements over conventional guidance methods such as proportional navigation. The kinematic efficiency attainable with modern control theory derived guidance laws suggest similar improvements may be achieved for the autopilot design. Guidance and control design which historically had been decoupled because of time constant separations are no longer applicable because of today´s stressing missile aerodynamic configurations driven by the demand for greater maneuverability. An approach is presented which applies LQR methodologies with observers/estimators to arrive at a more optimal guidance-control design for an advanced beyond-visual-range air-to-air missile. The approach is based upon back-to-turn steering logic. Application of LQR techniques is made to a coupled roll/yaw lateral plane autopilot design. The optimality and performance of this design are demonstrated via stability and response.