DATABASE MODEL FOR HIERARCHICAL CONTROL OF MANUFACTURING CELL SYSTEMS IN A MANUFACTURING SHOP

To access a large amount of static and dynamic data sets in achieving flexible manufacturing system (FMS) control functions, a corresponding database structure must be designed to effectively support the control. Within the context of a hierarchical manufacturing control architecture, this paper discusses the development of a semantic database structure for the control needs of manufacturing cell systems in a shop. A conceptual data model is first developed using entity-relationship diagrams (ERD), and the database is then implemented from a relational data model by a database management system. An application program is used to illustrate the production control command decomposition in a manufacturing shop that consists of several manufacturing cells. Feedback of control commands execution is also discussed. It is shown that the data flows in the hierarchical manufacturing control can be effectively supported by the developed databases and query interface.