Control and anticontrol of chaos

This article offers an overview on some commonly concerned issues related to control and anticontrol of chaos. Similar to conventional systems control, the concept of controlling chaos is first to mean suppressing chaos in the sense of stabilising chaotic system responses. The process of chaos control is now understood as a transition between chaos and order and, sometimes, from chaos to chaos, depending on the application of interest. Anticontrol of chaos, in contrast to the main stream of ordering or suppressing chaos, is to make a nonchaotic dynamical system chaotic, or to retain/enhance the existing chaos of a complex system. Anticontrol of chaos has emerged as a theoretically attractive and potentially useful new subject in system control theory and time critical or energy-critical high-performance applications.