| A general method to facilitate the exchange of geometric and related data between heterogeneous computer aided design and manufacturing (CAD/CAM) databases with minimal or no knowledge of the database facility is described. The system includes (1) a language, Common Database Interface Language (CDIL), to describe control and communication parameters, object, entity, and property descriptions, and entity mapping table, and entity translation processes, (2) a virtual database facility interface composed of database management system dependent functions to retrieve, store, link, unlink, and delete objects, entities, and properties, and (3) a run-time system that performs flow control and dynamic entity and memory management for the exchange of data between multiple common database facilities, between a common database facility and an intersystem communication file, and within a single common database facility.; The method has the advantages of flexibility, expansibility, portability, and efficiency over the current pre- and post-processor method of data exchange and provides the missing link between the development of common database facilities such as NASA's Integrated Program for Aerospace-vehicle Design (IPAD) and the development of exchange formats such as the Initial Graphics Exchange Specification (IGES) for data exchange between CAD/CAM databases, systems, and application programs.; Results are presented which illustrate the advantages of the method and demonstrate the application of the prototype software in transferring and translating data between CADAM input files, IGES output files, and a database facility established with the Relational Information Manager (RIM). |
