How Autopilot Requirements Constrain the Aerodynamic Design of Homing Missiles

When an aerodynamically controlled missile is used in a homing application, the transfer function of the vehicle becomes part of an overall homing and attitude control feedback loop. Therefore, the missile must be designed so that its aerodynamics meet the constraints required to accomplish homing successfully. For radar homing, these constraints are stringent enough to require an autopilot that controls the aerodynamic transfer function using body instruments and internal feedback loops. Even with an autopilot, there are limits on the aerodynamic moment parameters such as M¿ and M¿ that must be considered at the very beginning of the missile system design. This paper explores the nature and sources of these limits and presents numerical examples to illustrate what kinds of numbers are required.