Berlin 2012 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 6: Delay Dynamics

DY 6.6: Vortrag

Montag, 26. März 2012, 16:15–16:30, MA 144

Experimental control of chaos by variable and distributed delay feedback — •Thomas Jüngling¹, Aleksandar Gjurchinovski², and Viktor Urumov² — ¹Institute for Theoretical Physics, University of Würzburg, Germany — ²Faculty of Natural Sciences and Mathematics, Saints Cyril and Methodius University of Skopje, Macedonia

Unstable steady states can be stabilized by time-delayed feedback with variable or distributed delay. Compared to the classical control method with a single constant delay, it has been theoretically shown that such kind of feedback can improve the stability properties significantly. Here we investigate this phenomenon experimentally for a chaotic electronic circuit. Time-delayed signals are obtained by use of digital delay lines, which are driven by an external clock. A modulation of the clock frequency results in a delay time modulation. The use of many delay lines as well as the application of filters results in a delay distribution. The steady state of the oscillator could be stabilized with these methods for comparably large sets of parameters, confirming the theoretical prediction and the robustness of the presented technique. A restricted version of our control scheme was successfully applied to the control of unstable periodic orbits, also resulting in improved stabilization. Finally, an intuitive explanation of the phenomenon is given in terms of classical diffraction and interference.