We consider the control of a class of chaotic systems, which covers the for
ced chaotic oscillators. We focus on two control problems. The first one is
to change the dynamics of the system to a new one which exhibits a desired
behavior, and the second one is the tracking problem, i.e., to force the s
olutions of the chaotic system to track a given trajectory. To solve these
problems we use observers which could be used to estimate the unknown state
s of the system to be controlled. We apply the proposed method to the contr
ol of Duffing equation and the Van der Pol oscillator and present some simu
lation results. (C) 2001 Elsevier Science B.V. All rights reserved.