Robustification of GPC controlled system by convex optimisation of the Youla parameter

This paper presents a methodology for enhancing the robustness of a GPC controlled system by convex optimisation of the Youla parameter. This methodology requires as a first step the design of an initial GPC controller; this controller is then robustified considering temporal and frequency constraints. In this way, a compromise between robustness and closed loop behaviour can be easily managed. By means of the Youla parametrization, temporal and frequency constraints are formulated within a convex optimisation framework and the optimal parameter Is obtained by solving this optimisation problem. In this paper the robustness of the controller regarding model uncertainties in high frequency is enhanced while respecting a temporal template for the disturbance rejection.