Robust discrete-time simple adaptive regulation

Robust simple adaptive controllers are proposed for regulation of linear discrete-time systems with parameter uncertainties. Sufficient conditions for closed-loop stability of the proposed control scheme are derived. These lead to the requirement of almost strictly positive realness of the plant, which is shown to be equivalent (under certain conditions) to a minimum-phase requirement. A numerical example is given that demonstrates the applicability of the proposed method and the simplicity of its implementation.