Gain scheduled missile autopilot design using observer-based H∞ control

This paper studies gain scheduled autopilot design in the pitch axis. To achieve the tracking specification with both stability and performance robustness for pitch autopilot design, frequency shaping is adopted and H_∞ optimization is employed. It it shown that with suitable modification of the design objective in Nichols, Reichart, and Rugh (1993), the resulting central H_∞ controller has an observer form and it can be computed without iteration. This is especially attractive for gain schedule implementation. The performance of a typical pitch autopilot synthesized by the proposed design method is then evaluated by computer simulations