Optimal controlled variable selection for individual process units in self optimizing control with MIQP formulations

In order to facilitate optimal operation of process plants in the presence of disturbances, optimal control structure selection is important. In this paper we review the controlled variable selection, c = Hy, where y includes all the measurements. The objective is to find the matrix H such that steady-state operation is optimized when there are disturbances and inputs are adjusted to keep c constant. Several cases are studied such as optimal individual measurements, optimal combinations of fewer/all measurements and combinations of disjoint measurement subsets of fewer/all measurements. The proposed methods are evaluated on a distillation column case study with 41 trays.