A robust economic MPC for changing economic criterion

This note presents a robust economic MPC controller, suitable for changing economic criterion. The proposal ensures feasibility under any change of the economic criterion - thanks to the use of artificial variables and a relaxed terminal constraint - and robustness in presence of additive bounded disturbances, by means of nominal predictions and restricted constraints. The controlled system under the proposed controller is shown to be Input-to-State Stable (ISS), in the sense that it is asymptotically steered to an invariant region around the best admissible steady state. The properties of the proposed controller are highlighted in a simulation example on an isothermal stirred-tank reactor.