Adaptive robust steady-state tracking control

Adaptive robust steady-state tracking is discussed and a solution provided in the paper under the assumption of norm-bounded parametric disturbances. The question to be answered in this paper is, whether similar steady-state robust performance could be achieved by an adaptive scheme. It is shown that there is such an adaptive scheme, which is not only stable, but achieves an asymptotic robust performance which can be set arbitrarily near to that for a known plant, even if the bound of the perturbation is unknown. The assumptions under which this scheme exists are general, there is no requirement on the knowledge of minimum phase property or the sign of the high frequency gain as this is a basic requirement in some advanced schemes.