Stabilizing economic model predictive control of constrained nonlinear systems

This paper proposes a novelty economic model predictive control (EMPC) scheme with guaranteed stability for constrained nonlinear systems. Some auxiliary positive-definite functions at economy optimal equilibrium points are introduced for economic performance functions that are generally non-convex and non-positive-definite. The optimal value function of the auxiliary function is used to define an adjustable stability constraint which is imposed on the original EMPC optimization problem. By the triplet of terminal constrained sets, terminal penalty functions and local controllers, it is proved that the closed-loop system is asymptotically stable at the economically optimal equilibrium point and has an asymptotic average performance. Moreover, the proposed EMPC scheme is extended to optimization control of multiple economic performance functions, together with the concept of multi-objective utopia points. Then a stabilizing multi-objective EMPC scheme is presented. Finally, the effectiveness of the obtained results is illustrated by a simulation example of a continuously stirred tank reactor. Copyright © 2016 Acta Automatica Sinica. All rights reserved.