Uniform Treatment of Integrated CAD/CAM Data and Metadata

Abstract

An integrated data base is the heart of an integrated manufacturing system. It serves as the glue to bind together heterogeneous component systems, which are often developed independently for supporting product design, process planning, manufacturing, product inspection and testing, and product service and maintenance, into a fully integrated system. To establish and use such a data base, a data model that is very rich in semantics is necessary to model the complex structural properties, operations, and constraints associated with the data objects commonly found in computer aided design (CAD)/computer aided manufacturing (CAM) applications. Furthermore, it would be necessary to have a data dictionary facility to allow the users of various component systems to define, display, and modify the schema of the integrated data base. This paper presents a semantic association model called SAM*, which contains six general constructs for modeling the complex relationships (or associations) among data objects. These constructs can be used in an embedded or recursive fashion to allow very complex objects to be explicitly defined in a schema that contains the metadata of an integrated data base. In this work, the same semantic model is also used to model the contents of the schema so that the metadata, as well as the application data of an integrated data base, can be uniformly defined, stored, displayed, modified, and manipulated by the users. This paper also describes an interactive data dictionary system implemented for the definition and manipulation of metadata and application data modeled by the semantic model.