Automated knowledge base generation from CAD databases using relaxation techniques

A system that converts the computer-aided design (CAD) database description of a process control system into a frame-oriented knowledge base for a diagnostic expert control system is described. The target expert system for the automated knowledge generation is NASA´s Knowledge-Based Autonomous Test Engineer (KATE), developed to assist in the monitoring and control of Space Shuttle ground support systems. KATE retains the structure of the system it has knowledge about in its frame representations and derives understanding of the target system from intercomponent relationship knowledge held within those frames. A CAD database generated for a particular process control system contains all the structural information required to reconstruct the system, but little or no functional data. A functional description can be inferred in some cases from the CAD data; however, the complexity of such a system for a domain as large as process control is extensive. The construction and operation of an automated knowledge generation software system that performs the conversion from CAD database to knowledge base are discussed