Representing functionality and design intent in product models

The specific objectives of this work were: 1) To define and conceptually model the relations among functionality, features, and dimensions and tolerances. 2) To define and conceptually model design intent. 3) To develop a representation scheme to capture objectives (1) and (2) in a computer-intelligible format. 4) To demonstrate the feasibility of this representation scheme through the development of case studies and a prototype modeler. To date, objectives (1), (2) and (3) are completed and objective (4) is in progress. The proposed framework divides the product models into two realms: a physical realm, and a meta-physical realm. The physical realm model contains the information commonly associated with physically-based models: geometry, topology, dimensions and tolerances, materials, etc. The meta-physical model contains the meta-knowledge of the physical design, i.e., the information which describes the nature, structure, behavior, and reason for existence of entities in the physical model. This approach to modeling products, called the meta-physical modeling paradigm, combines the results of many previous research efforts. The meta-physical modeling paradigm utilizes Product Definition Units, or PDUs, at several levels of abstraction including need, function, physical principle, embodiment, artifact type, and artifact instance. The key to the linking of the meta-physical model with the physical model is the concept of a feature. A feature is the physical realm dual of a meta-physical PDU. The design and implementation of a prototype system has begun. The system, designed as an object-oriented extension to the ACISqq* system, is called myqqacis. myqqacis contains a meta-physical modeler, a dimension and tolerance modeler, and a feature modeler, in addition to the ACIS geometric modeler. Currently myqqacis demonstrates the ability to capture the design intent and functionality of physical objects and their features. Upon completion myqqacis will demonstrate the ability to capture the design intent and functionality underlying the dimensions and tolerances of physical objects. In summary, meta-physical modeling provides the capability to capture the function and design intent of systems, assemblies, parts, features, and even individual dimensions and tolerances. A demonstration system is under construction to demonstrate these capabilities.