SOLUTION TO THE BLOW-UP PROBLEM IN ADAPTIVE CONTROLLERS.

Abstract

This paper addresses the blow-up problem associated with the parameter estimation part of an adaptive controller. A partial solution to the problem has been devised by the introduction of a variable forgetting factor. However, this does not eliminate the blow-up possibility. This is shown by simulation experiments on two different models. A new method which completely solves the blow-up problem is presented. This method is presented in two essentially equivalent formulations. One of the formulations is based upon a vector variable forgetting factor, while the other is a Kalman filter approach. This new method and the scalar variable forgetting factor are compared by means of simulation experiments.