The Ontology-Based Semantic Reasoning Method for Non-standard Part Datum Construction

In the field of mechanical engineering, standard parts, such as shaft and gear, have standardized tolerance specification design process due to its formalized shapes and dimensions. However, non-standard parts are much more different because their geometrical shape and size are not fixed. Non-standard parts have widely application in automotive and aerospace, and the tolerance specification is mainly dependent on engineer experience and default standards. To this end, this study proposed an ontology-based method of datum reference frame (DRF) for non-standard parts. In this study, a hierarchical tolerance information representation model was constructed. The knowledge reasoning algorithm was established via experience and ISO GPS standards, considering the knowledge isomerism of human engineers, a CAE model was proposed to evaluate the reliability of reasoning results. A case study was conducted to demonstrate the effectiveness of proposed method, the algorithm presented in this paper can be used in the computer-aided tolerance development.