DELAYED FEEDBACK-CONTROL OF CHAOS BY SELF-ADAPTED DELAY-TIME

We present a novel technique for stabilizing unstable periodic orbits of chaotic systems. It uses a continuous feedback loop in the form of the difference between an actual and a delayed output signal of the sy stem with a variable delay time. This time is chosen to be equal to th e interval between the last and the kappa th previous maximum of the o utput signal and is changed at every kappa th maximum. During the proc edure, the delay time asymptotically tends to the period of the period -kappa unstable periodic orbits and the control signal vanishes. The m ethod is illustrated with the help of the Rossler ordinary differentia l equations and the Mackey-Glass delay differential equations.