The need for a systems perspective in control theory and practice

Control systems have had a profound impact on society as theories, techniques, and algorithms have migrated from the laboratory to thousands of products. As the control community continues to improve its solutions, ideas are being generated for a new era of applications that are fundamentally different from their predecessors. Where applications once employed control systems for greater performance, new applications require control systems for their very existence. Examples of these types of systems are ultra-agile military aircraft, large-space-structure observatories, and formation-flying spacecraft constellations. This control-enabled class of systems (also called high-performance systems) is changing the role of control science in engineering. We examine the new role of control science in high-performance systems and its implication for control theory. We describe the traditionally serial role of control science in systems design and the evolving iterative system-control design process used for high-performance systems. Next, we discuss several high-performance systems that use this iterative design process. Then, we describe past work that is related to systems-control analysis-synthesis (S-C-A-S), followed by an examination of fundamental control theory concepts that may be extended as part of an S-C-A-S theory. Finally, we present conclusions.