QUASI-CONTINUOUS CONTROL OF A BRONZE RIBBON EXPERIMENT USING TIME-DELAY COORDINATES

We investigate quasicontinuous versions of the Ott-Grebogi-Yorke(OGY) control method in a bronze ribbon experiment using time-delay coordina tes for the reconstruction of the attractor. We apply as quasicontinuo us control methods the local control method and the minimal expected d eviation method. As is known for the original OGY method with time-del ay coordinates, values of the control parameter at previous times appe ar in the linearized dynamics. We discuss two possible ways to derive from this linearization feedback control formulas. These are the exten ded state space approach and a modified control requirement-that deman ds stabilization not in the next time Step but after w + 1 time steps, where w is the number of preceding parameter dependences of the linea rized dynamics. We show theoretically and demonstrate in the experimen t that for the quasicontinuous control methods considered in this pape r only the modified control requirement shows satisfying results in th e control experiment.