Abstract:

To reduce the uncertainty in mechanical product design and to solve the problem of effective sharing and smooth transferring of assembly tolerance information among heterogeneous CAX systems, we construct an ontology knowledge base for the assembly tolerance synthesis. We first analyze the assembly tolerance knowledge based on the ontology that contains abundant semantic knowledge and semantic structures. The web ontology language (OWL) is used to define the concepts and relations, and the semantic web rule language (SWR) is used to define the constraint conditions and distribution experience. Afterwards, the OWL-based structure knowledge is mapped to facts, the SWRL-based constraint knowledge is mapped to rules, and an ontology knowledge base for the assembly tolerance synthesis is constructed based on the inference engine. Meanwhile a prototype system of the assembly tolerance synthesis is developed based on the ontology, which can automatically generate the assembly tolerance types and assembly tolerance values.

Key words: tolerance synthesis, ontology, knowledge base, automatic generation