2 v 1 1 6 Se p 19 95 RECURSIVE PROPORTIONAL - FEEDBACK AND ITS USE TO CONTROL CHAOS IN AN ELECTROCHEMICAL SYSTEM

We report the successful application of a simple recursive proportional-feedback (RPF) algorithm to control chemical chaos observed during the electrodissolution of a rotating copper disk in a sodium acetate/acetic acid buffer. The RPF method is generally applicable to the control of chaotic systems that are highly dissipative and adequately described by one-dimensional maps of a single variable. The successive minima of the measured anodic current generate a return map that is used to implement the control strategy and the anodic potential is the control parameter. Unstable periodic orbits of period one and period two are stabilized by applying small perturbations (≈ 0.05%) to the anodic potential on each cycle of the periodic oscillation. Experimental evidence is presented to indicate why the RPF method was necessary in this system and the theoretical robustness of the algorithm is discussed.