Tuning optimal-robust linear MIMO controllers of chemical reactors by using Pareto optimality

Pareto optimality was introduced in order to find the better equilibrium between performance and robustness of linear controllers by the simultaneous minimization of the quadratic-error and quadratic-control functions integrals. The Pareto optimization problem was solved setting the characteristic matrix eigenvalues in the region of left complex semi plane where vertical bar lm/Re vertical bar < 1 as constraint. 2D Pareto fronts were built with the quadratic-error function integral vs. quadratic-control function integral. The proposed method was applied for tuning linear controllers of three chemical reactors with different kinetic equations and mix patterns. In the three situations, the Pareto optimality procedure improved the controllers' performance and robustness with respect to controllers previously tuned by different methods. (C) 2011 Elsevier B.V. All rights reserved.