Functional architecture and enabling technologies for distributed shop floor control

Abstract

The control and functional architecture for shop floor control has been studied to manipulate shop floor resources efficiently. In a hierarchical control system, an upper level controller coordinates the activities of a group of lower level controllers in a master - slave manner. Recently, to overcome its various disadvantages, a distributed shop floor control system (SFCS) has been proposed, in which each controller cooperates to manage the entire range of manufacturing activities from order booking through design, production and marketing. Its major characteristics include autonomy, intelligence, and cooperation. Each controller attached to the shop device is required to perform monitoring of external data, decision-making for optimal planning and scheduling, and execution of scheduled tasks. The objective of the paper is to define the modularized functions of each controller in the distributed SFCS that represents the functional architecture. To this end, the functions are gathered and defined for each resource and generalized to build the functional architecture. Moreover, enabling technologies for each function are discussed in the architecture. One such methodology can be plugged into a controller in the implementation stage. Thus, the designed architecture provides a comprehensive insight into the functions and methodologies of the distributed SFCS, which consequently enables the rapid development of a control system.