Parameter convergence of a class of adaptive controllers

Concerns a class of adaptive control schemes, motivated from nonlinear systems theory, for minimum-phase linear time-invariant plants. Under certain assumptions on the plant transfer function, these schemes guarantee uniform signal boundedness and good transient and steady state response for the regulation or tracking error. In this paper we show that these schemes can guarantee exponential convergence of the tracking and parameter error to zero provided the reference signal is sufficiently rich.