Study on the expression specifications of geometrical products for function, design, manufacture and verification based on the improved GPS language

摘要

For the design, manufacture and verification, a consistent geometrical model for the product functional geometry is required. In this paper, we analyze the relation of the geometrical model with the design, manufacture, and verification of the geometrical product. Based on the improved GPS language, the new concepts and mathematical tools for the geometrical specifications are defined. A surface model defined in the new GPS can be divided into three models: nominal, specification and verification surface model. Expanded geometrical features exist in three "worlds": nominal, specification and verification worlds. Operations are specific mathematical tools to obtain ideal or non-ideal features, or values of characteristics, their nominal value and their limit(s). The operations used to define the specifications can be divided into seven classes: partition, extraction, filtration, association, collection, construction, and evaluation. With a simple mechanism as an example, the geometrical expression specifications for the functions, design, manufacture and verification of a product are illustrated.