Design and robustness of delayed feedback controllers for discrete systems

Phys Rev E Stat Nonlin Soft Matter Phys. 2004 May;69(5 Pt 2):056207. doi: 10.1103/PhysRevE.69.056207. Epub 2004 May 12.

Abstract

We study a matrix form of time-delay feedback control in the context of discrete time maps of high dimension. In almost all cases where standard proportional feedback control methods can achieve control, time-delay feedback controllers containing only static elements can be designed to achieve identical linear stability properties. Analysis of an example involving a ring of coupled maps that can be controlled at only two sites demonstrates that the time-delay controller equivalent to a standard optimal controller can be equally robust in the presence of noise, except at special points in parameter space where the uncontrolled system has a mode with Floquet multiplier exactly equal to 1. Numerical simulations confirm the results of the analysis.