A stable MRAC design for discrete plants with unmodelled dynamics (Q1824592)

A model reference adaptive control scheme for discrete systems is presented. The algorithm maintains stability around the equilibrium of the tracking error in the presence of unmodelled dynamics. The only knowledge required is the lower and upper bounds for the absolute values of the parameters and orders of the unmodelled dynamics. The control input required for the plant is given in the third step of the proposed algorithm. Theorem 1 and 2 of the paper provide the stability results. They show that the adaptation error asymptotically tends to zero, the input/output sequences are both bounded and that a measure of the overall input/output system energy is bounded. The applicability of the method is demonstrated by a simulation result.