Ontology-Based Representation and Verification to Enable Feature Interoperability Between CAD Systems

Data interoperability between computer-aided design (CAD) systems remains a major obstacle in the information integration and exchange in a collaborative engineering environment. The standards for CAD data exchange have remained largely restricted to geometric representations, causing the design intent portrayed through construction history, features, parameters, and constraints to be discarded in the exchange process. In this research paper, an ontology-based framework is proposed to allow for the full exchange of semantic feature data. The Ontology Web Language (OWL) is used to represent feature types as well as the concepts and properties that define features, which allows the use of existing ontology reasoning tools to infer new relationships and information between heterogeneous data. Boundary representation (B-Rep) data corresponding to the output of the feature operation is also stored for purposes of feature identification and translation verification. The base ontology and a small feature library are built in OWL, and a combination of OWL and SWRL (Semantic Web Rule Language) rules are developed to allow a feature from an arbitrary source system to be automatically classified and translated into the target system through the use of a reasoner. These rules relate input parameter and reference types to expected B-Rep objects, allowing classification even when feature definitions vary or when little is known about the source system. In cases when the source system is well known, this approach also permits direct translation rules to be implemented. With such a flexible framework, a neutral feature exchange format could be developed.