ADAPTIVE INTEGRAL CONTROL OF TIME-DELAY SYSTEMS

It is well known that if the steady-state gain G(0) of a stable lumped system, with transfer function G(s), is positive, then compensating t he system by an integral controller k/s, where k is a gain parameter, leads to a stable closed-loop system which achieves tracking of arbitr ary constant reference signals, provided that the gain parameter Ic is positive and sufficiently small. It is also well known that this resu lt extends to certain classes of differential-delay and distributed pa rameter systems. The authors derive an adaptive version of the above r esult for the class of stable lumped systems with output delay, i.e. t hey show that the gain parameter k can be tuned adaptively, so that tr acking is achieved for any system of this class. The resulting adaptiv e tracking controller is not based on system identification or paramet er estimation algorithms, nor is the injection of probing signals requ ired.