CONTINUOUS CONTROL OF CHEMICAL CHAOS BY TIME-DELAYED FEEDBACK

Continuous time delayed feedback, based on a method by Pyragas, is app lied to the Belousov-Zhabotinsky (BZ) reaction to stabilize unstable p eriodic orbits embedded in the chaotic attractor. Our experimental res ults are compared with numerical calculations of the four-variable mod el (Montanator) for the BZ reaction. The Pyragas method is also applie d to calculations of a mechanism (Aguda-Larter model) for the peroxida se-oxidase reaction. In addition to the stabilized orbits in the stran ge attractor, new periodic, chaotic, and steady states are produced fo r large values of the feedback function in both models. The possible r ole of chaos and feedback in nature is discussed.