A Rule-Based Reasoning Approach for Geometric Specifications: A Case Study

In the integration of design and manufacturing processes, it is crucial to incorporate tolerance information into existing solid models. These specifications play a vital role in facilitating subsequent tasks such as automatic process planning, manufacturing, inspection, and assembly. Within a Computer-Aided Design (CAD) system, assembly models consist of components with mating relations, and each component comprises geometric features. In a hierarchical structure, these characteristics exhibit interconnections and spatial associations, refining the relationships between components. Starting with a top-down approach, the development of a tolerance representation model to outline different tolerance types should begin with the formal definition of relationships between mating components. Subsequently, the attention shifts to formalizing the mating connections between geometric features. Through these formalized processes, a model for articulating tolerance types can be developed. This paper outlines the construction of a tolerance model for a mechanical assembly, enabling the generation of geometric specifications from a CAD model of the assembly. The successive stages of this method are showcased using an illustrative example.