La Commande prédictive généralisée robustifiée par la paramétrisation de Youla

Abstract

This work describes a methology for enhancing the robustness for predictive control laws, develloped by RODIRGUEZ. Particularly the Generalised Predictive control (GPC) strategy, based on the Youla parametrization. First, the GPC, its robustness characteristics, the equivalent RST polynomial controller and the usuel methods used to robustify this kind of the Youla parametrization, frequancy and temporal closed loop specifications are fomulated within a convex optimisation framework. This problem transformation is possible thanks to the parametrization of all stabilising controllers operated by the Youla parameter. Specifications reflecting nominal performance and robustness stability using unstructured uncertainties are used. It is shown that the definition of temporal templates permits to easily adjust the compromise between robustness and parformance. The develped methodology is then applied to robustify a GPC controlled positioning benchark, including an induction motor, aiming at reducing the impact of measurement noise and inertria variation of the system whil respecting a temporal template for the disturbance rejection.