Discrete model-reference adaptive control using only input and output measurements

Abstract

A globally stable discrete model-reference adaptive controller design using only input and output measurements is presented. The rejection of both measurable and unmeasurable load disturbances is included in the adaptive system. The use of state-variable filters ensures that the basic scheme is applicable to a process with moderate measurement noise. With large measurement noise, an extended scheme using the technique of instrumental variable is introduced. The performance of these designs is substantiated by simulation.