Comparative Account of Robust H∞ Techniques for Missile Autopilot Design

H∞ control techniques are prominently used as solutions for flight control problems. From the literature, a variety of techniques is reported in the last three decades with specific merits and demerits, which, when applied to multiple flight control scenarios, showing trade off in terms of performance and robustness. However, all these methods possess superior performance when compared with that of classical approaches. In this paper an attempt is made to provide an insight into the requirements and criticalities in the design of missile autopilot. This paper introduces some of the significant H∞ control techniques like H∞ mixed sensitivity, H∞ loop shaping and μ synthesis, with specific emphasis on analysis of autopilot design. A comparative account of modern control methods is presented on the basis of system performance and robustness, which will be helpful in the selection of the appropriate design method for specific application.