Using periodic modulation to control coexisting attractors induced by delayed feedback

A delay in feedback can stabilize simultaneously several unstable periodic orbits embedded in a chaotic attractor. We show that by modulating the feedback variable it is possible to lock one of these states and eliminate other coexisting periodic attractors. The method is demonstrated with both a logistic map and a CO2 laser model. (C) 2003 Elsevier B.V. All rights reserved.