1 Department of Automation, Technical University of Denmark
Control problems in the process industry are dominated by non-linear and time-varying behaviour, many inner loops, and much interaction between the control loops. Fuzzy controllers have in some cases nevertheless mimicked the control actions of a human operator. For high level control and supervisory control several simple controllers can be combined in a priority hierarchy such as the one developed in the cement industry. An example of a distillation column shut-down illustrates a design procedure.