A distributed architecture for reconfigurable control of continuous process operations

Abstract

This paper considers a new distributed approach to reconfigurable control of continuous process operations such as in chemical plants. The research is set on a premise that emerging business pressures of product customization and industrial globalization will lead to increased need for reconfigurability in process plants. The ability of processes to support dynamic and smooth reorganization of process schemes in tandem with the changing requirements of supply chains will become important in future. Conventional control approaches based on hierarchical architectures are limited in dealing with such emerging requirements due to their inflexible structures and operating rules. Instead, more distributed approaches are required which can support increased level of reconfigurability in control systems, especially at the lower levels in hierarchy where the visibility to disturbances remains high. In this paper, one such distributed approach is considered based on the concepts of holonic manufacturing and supply chain management. The proposed approach distributes the functionality of process control into several reconfigurable process elements. These elements, while having a stand-alone capability for making their own control decisions, are also able to reconfigure themselves into alternative process schemes which evolve with the changing requirements of production. An analogy between process plants and so-called dynamic supply networks or virtual enterprises is used in this paper to define the composition of reconfigurable process elements and their operations. The proposed approach is shown to offer improved process control system reconfigurability and a control architecture which is compatible with the supply chain management needs at the next higher level. The purpose of this paper is qualitative and motivational. It is aimed to propose a new research direction in the field of reconfigurable process control.