A novel time-delayed control method is proposed for stabilizing inherent un
stable periodic orbits (UPOs) in chaotic systems. Differing from the common
ly used linear time-delayed feedback control form, we adopt an optimal cont
rol principle for the design of the time delayed feedback control. We explo
re the inherent properties of chaotic systems and use the system states and
time-delayed system states in forming a performance index so that when the
index is minimized, the resulting controller enables stabilization of the
desired UPOs. The effectiveness of the method is confirmed by computer simu
lations. (C) 2000 The Franklin Institute. Published by Elsevier Science Ltd
. All rights reserved.