Future directions in L∞ robust control theory

This paper presents a perspective on the L^∞/conicsector/singular-value theory for robust control system analysis and design. Included is a brief survey of the state-of-the-art and its shortcomings. The paper discusses some of the ongoing efforts to resolve the shortcomings and expand the scope of applicability of the L^∞ theory, including the using of conformal mappinas and diagonal scalinas to reduce the conservativeness of L^∞ synthesis, the needs for non-conic robustness analysis/synthesis, robust adaptive control, decentralized robust design and control, etc.