On the structural properties of some discrete time adaptive control systems

This paper develops some of the basic properties of a particular type of adaptive control process. Because of the ambiguity which surrounds the adjective "adaptive", the essential property which characterizes this class of adaptive control problems is considered in detail. The usual type of performance criterion does not provide a satisfactory ordering of the control policies in these problems. Three approaches are introduced which avoid this difficulty, and their relative merits are studied.