A control structure using an adaptive observer

The state and parameter estimates produced by a recently reported adaptive observer [3] are used to form an adaptive control scheme. For a large class of inputs, the adaptive process will converge in the sense that asymptotically the system transfer function will exhibit a set of desired poles. The rate of parameter convergence can be made arbitrarily fast by appropriate choice of the constant gain parameters in the adaptive laws. However, a limitation of the apparent closed-loop control structure is exposed.