TABLE OF CONTENTS Roughly speaking, "to adapt" means to change a behavior to conform to new circumstances. The term adaptive system has a variety of specific meanings, but it usually implies that the system is capable of accommodating unpredictable disturbances, whether these disturbances arise within the system or external to it.
Adaptation is a fundamental characteristic of living organisms since they attempt to maintain physiological equilibrium in the midst of changing environmental conditions. An approach to the design of adaptive systems is then to consider the adaptive aspects of human or animal behavior and to develop systems that behave somewhat analogously.
An adaptive controller is thus a controller that can modify its behavior in response to changes in the dynamics of the plant and the character of the disturbances. The basic objective of an adaptive controller is to maintain a consistent performance of a system in the presence of uncertainty or unknown variation in the plant parameters, which may occur due to nonlinear actuators, changes in the operating conditions of the plant and nonsatisfactory disturbances acting on the plant.
Since ordinary feedback also attempts to reduce the effects of the disturbances and plant uncertainty, then immediately the question arises in one's mind that what is the difference between feedback control and adaptive control? An adaptive controller is a controller with adjustable parameters and a mechanism for adjusting the parameters. An adaptive control system can be thought of as having two loops. One loop is a...
