Resonant control of electrochemical oscillations

We report experimental control of complex (periodic and chaotic) oscillator y dynamics in an electrochemical system by applying a nonfeedback control m ethod. By choosing an appropriate frequency for the periodic modulation of an accessible control parameter (e.g., circuit potential) not only are the chaotic dynamics converted to regular periodic behavior (controlling chaos) but also the character of the oscillatory dynamics is altered (for example , 1(1) --> 1(0)). This is different from previously reported experiments in volving simple entrainment of oscillatory dynamics, since in our experiment s the frequency of sinusoidal modulation is chosen such that the existing u nstable dynamics are targeted and subsequently stabilized. Consequently, th e maximum amplitude of the control signal is less than +/-5% of its base va lue. Since resonant control strategy can be easily implemented without a co mplicated precontrol procedure it seems relevant for applications to real s ystems.