Adaptive Robust Regulation for Plants with Coprime Factor Perturbation in the Presence of Unknown Disturbances

This paper investigates an adaptive robust regulation problem when a discrete-time plant is subjected to both coprime factor perturbation and unknown external disturbances. Firstly, we present a design method of optimal robust regulation controller for plant with coprime factor perturbation and unknown external disturbances. Then, based on the idea of set-membership identification, we propose a recursive estimation for extended parameters in which includes the parameters of nominal model and the bound of unmodelled dynamics and disturbances. Finally, we propose a novel adaptive robust tracking scheme, a tight bound for robust performance and prove the overall convergence of the adaptive algorithm. The adaptive scheme proposed in this paper has good robust stability and asymptotically optimal robust performance