Efficient Convex-Lifting-Based Robust Control of a Chemical Reactor

Abstract

Efficient operation of chemical reactors is a very challenging task. Continuous stirred-tank reactors (CSTRs) are important devices of the process industry. CSTRs have complex non-linear behaviour. CSTRs operation is influenced by various uncertain parameters. The industrial operation of CSTRs still offers lots of opportunities to become more energy efficient. The optimisation-based robust control design evaluates optimal control action in the presence of the uncertain parameters subject to the constraints on manipulated variables and controlled variables, taking into account economic criteria. The main contributions of this project are designing and tuning of the advanced control strategy for a CSTR. Particularly, the robust control method based on the convex lifting is designed for a laboratory CSTR. The novel convex-lifting-based robust control strategy considering the improved control law is developed to optimise the control performance in real-time control. The presented case study is the first analysis investigating the application of robust convex-lifting based control on a CSTR. The reference tracking problem is investigated under various working conditions. In the case study, the controllers are designed with (i) single tunable robust positive invariant (RPI) set and (ii) multiple tunable RPI sets. The designed offset-free convex-lifting-based robust controllers are compared with respect to their control performance and the computational complexity.