Coordinated Decentralised Control Design and Distillation Pilot Plant Application

Abstract

The Coordinated Decentralised Control forms a useful approach to control a complex industrial process. It enables the design of a multilevel control system in the form of a hierarchical network of control and decision centers. The vertical information transfer help for the coordination in a hierarchical control and the horizontal information transfer is used for the cooperation in decentralised control. The relations between the control centers are expressed by the tracking of the used process models. The aggregated model situated on the upper level of the hierarchy is tracked by the detailed models of the lower level. Eventually a multiple model could be introduced to caracterise a process part in its various operating conditions. On the base of linear state variable models and the input-output quadratic tracking cost function, a Coordinated Decentralized Control Algorithm in the form of matrix modular computing blocs is presented. The stability study gives the condition to be satisfied for the interconnection of these centers. The application of the proposed approach to the experimental pilot plant with two distillation columns controled by a micro-computer distributed system is presented.