On decoupling control of uncertain and multivariable systems with time delays

This paper deals with multiple-input and multiple-output (MIMO) systems with time delays and in the presence of significant process uncertainties both internal and external. A predictive active disturbance rejection control (PADRC) design, combined with a decoupler, is proposed. The decoupler is designed to reduce the interaction among the loops based on the knowledge of process dynamics. The remaining interaction due to the imperfection of the decoupler, together with the internal and external uncertainties in the process, which could be quite significant, is then dealt with by an independent PADRC controller for each loop. The effectiveness of the proposed method is demonstrated in simulation studies using two well-known processes in chemical industry: the Wood and Berry system as well as the Vinante and Luyben system.