Adaptive optimal tuning of a general class of stable LTI systems with restricted inputs (Q5955792)

This paper addresses model reference adaptive control (MRAC) of asymptotically stable plants of unknown order with zeros located anywhere in the \(s\)-plane except \(s=0\). The authors relax three requirements that are typically imposed in MRAC approaches. They assume instead: (1) No a priori information is needed concerning the parameters, the order, or the relative degree of the plant; (2) The plant is allowed to be nonminimum phase; and (3) The input is not necessarily persistently exciting. The authors do assume that the plant is asymptotically stable and that the reference model has no zero at \(s= 0\). This unusual approach taken by the authors is motivated by a dissatisfaction with the conventional assumptions -- that they are unrealistic (minimum phase) or artificial (persistence of excitation). The authors' approach to MRAC has been applied in aircraft control, in power systems, and in automatic ship-steering.