Robust discrete decentralized model-reference adaptive control

In this paper we examine the stability (boundedness) properties of a discrete model-reference adaptive operating in a decentralized system. In common with the continuous time case first examined by Ioannou & Kokotovic [1], we find that a modification is also required to ensure the boundedness property in the discrete case. The correspondence between the MRAC and STR approaches is readily apparent in discrete time and we examine this aspect with regard to the modification required for the MRAC algorithm. An application example of the practical efficacy of this algorithm is given through an implementation on a third-order hydraulic actuator.