Dual-Control Autopilot Design for Combined Tail Fin & Divert Thruster Controlled Hit-to-Kill Interceptor

The direct hit requirement imposed on current generation missile interceptor design demands a fast airframe response. In aerodynamic tail-controlled missiles, system response time is driven by dynamic pressure and the transient “wrong way” effect inherent to tail-controlled designs. With high angle rates of change typically seen in terminal geometries, dynamic pressure and the “wrong way” effect limit the immediate correction commanded by guidance systems at a most critical time. A solution addressing both issues is the addition of divert lateral thrusters. Thrusters provide additional control authority in low dynamic pressure regions and counteract the “wrong way” effect. This paper presents a dual-control missile autopilot architecture for simultaneous thruster and aerodynamic control. Defining a new missile trim condition, it considers the control contributions of thrusters at autopilot design time in combination with aerodynamic tail control. This material is intended for professionals interested in a dual-control interceptor design seeking a practical design methodology.