A REMARK ON CHAOTIC BEHAVIOR IN ADAPTIVE-CONTROL SYSTEMS

This note deals with the control of a linear discrete-time system desi gned on the assumptions that we do not have explicit knowledge of the order of the plant. The objective is to cause the output to track a gi ven constant reference y, when the initial conditions are in a neighb orhood of y. In previous papers the presence of chaos was conjectured for an adaptive scheme where the plant to be controlled was a second- order one undermodeled by a first-order one. We show that with an adeq uate choice of the parameter estimator local regulation with exponenti al convergence of both the output and the parameter is obtained.