A retrospective correction filter for discrete-time adaptive control of nonmiminum-phase systems

We present a discrete-time adaptive control law that is effective for systems that are unstable, MIMO, and/or nonminimum phase. The adaptive control algorithm provides guidelines concerning the modeling information needed for implementation. This information includes a sufficient number of Markov parameters to capture the sign of the high-frequency gain as well as the nonminimum-phase zeros. No additional information about the poles or zeros need be known.We present numerical examples to illustrate the algorithm¿s effectiveness in handling nonminimum-phase zeros.