Non-linear control systems

Abstract

Control systems are prevelant in nature and in man-made systems. Natural regulation occurs in biological and chemical processes, and may serve to maintain the various constituents at their appropriate levels, for example. In the early days of the industrial revolution, governors were devised to regulate the speed of steam engines, while in modern times, computerised control systems have become commonplace in industrial plants, robot manipulators, aircraft and spacecraft, etc. Indeed, the highly maneuverable X-29 aircraft using forward swept wings is possible only because of its control systems, and moreover, control theory has been crucial in NASA's Apollo and Space Shuttle programmes. Control systems such as in these examples use in an essential way the idea of feedback, the central theme of this chapter.