Design of a factory floor sequence controller from a high level system specification

Abstract

Abstract The design of manufacturing systems and the development of manufacturing system controllers have become more closely linked as the manufacturing environment has become more automated. Specification of machining processes, materials handling functions, and operational decision-and-control functions by system designers determine the software specifications for controller designers who must automate the integration of machines and material handling equipment in accordance with the desired operational decision and control functions. This paper addresses the interface between manufacturing system design and controller design. It describes a high level design methodology that enhances communications between manufacturing system designers and controller designers, allows automatic generation of controller logic from that high level design, and provides a basis for analytically evaluating the operational decision and control functions specified by the system designers using the automatically generated controller logic. It can then be determined whether or not the manufacturing system and its controller will function in the desired manner. The high level design interface is established through IDEFO methodology. The design specification is then transferred into a petri net through a set of transformation rules. The reason for choosing IDEF0 methodology is its simplicity in communicating ideas and its current wide use in industry. The reason for using petri nets is that it provides a unique framework for specification, analysis, and implementation of controllers.