Design of robust, time-varying controllers for missile autopilots

The design of a longitudinal gain-scheduled autopilot for a tail-controlled missile using μ-synthesis control design techniques is discussed. The goal is to design a single controller to track commanded acceleration maneuvers with a steady state error of 0.5%, a time constant of less than 0.2 s, a step response overshoot of less than 10% and a maximum tail-deflection rate of 25 degrees/s/g. The controller is to provide robust performance over a range of ±20 degrees angle-of-attack and missile speeds between Mach 2 and 4. The controller must avoid saturating the tail-deflection actuator rate capabilities and destabilizing unmodeled high frequency flexible body modes of the missile