Feature-based tolerancing for advanced manufacturing applications

A primary requirement for the successful deployment of advanced manufacturing applications is the need for a complete and accessible definition of the product. This product definition must not only provide an unambiguous description of a product`s nominal shape but must also contain complete tolerance specification and general property attributes. Likewise, the product definition`s geometry, topology, tolerance data, and modeler manipulative routines must be fully accessible through a robust application programmer interface. This paper describes a tolerancing capability using features that complements a geometric solid model with a representation of conventional and geometric tolerances and non-shape property attributes. This capability guarantees a complete and unambiguous definition of tolerances for manufacturing applications. An object-oriented analysis and design of the feature-based tolerance domain was performed. The design represents and relates tolerance features, tolerances, and datum reference frames. The design also incorporates operations that verify correctness and check for the completeness of the overall tolerance definition. The checking algorithm is based upon the notion of satisfying all of a feature`s toleranceable aspects. Benefits from the feature-based tolerance modeler include: advancing complete product definition initiatives, incorporating tolerances in product data exchange, and supplying computer-integrated manufacturing applications with tolerance information.