ELECTRONIC CHAOS CONTROLLER

The occasional proportional feedback (OFF) controller introduced by Hu nt [1] and used for stabilizing periodic solutions in a number of chao tic circuits and also used in the stabilization of a chaotic laser has the disadvantage that it requires an external synchronizing signal. I n this paper, we describe a modified version of Hunt's controller whic h obviates the need for any external signals. We show how the controll er has been used successfully to remove chaos in the chaotic Colpitts oscillator. We also describe some theoretical results on the possibili ties for controlling a given chaotic system using the OFF method. We p rove that the possibility of stabilization depends on the behavior of the system in the neighborhood of the periodic orbit and not on the di mensionality of the attractor on the Poincare surface. (C) 1997 Elsevi er Science Ltd.