Modelling the integration between the design and inspection process of geometrical specifications for digital manufacturing

摘要

Geometrical Product Specifications (GPS) is a technical language which covers the standardization for micro/macro- geometry specifications. In today’s environment of globalization, out-sourcing and sub-contracting is increasing. Geometrical specifications of a product need to be detailed to a degree where nothing is left open to interpretation. To fulfil this, and to meet the requirements of digital manufacturing, it is necessary to integrate the design and inspection process of a geometrical specification. At the technical level, many functional operator/operations are employed in a geometrical specification. These functional operators/operations are based on rigorous mathematics, and they are intricately related and inconvenient to be used directly. Consequently, it is of practical utility to build an integrated information system to encapsulate and manage the information involved in GPS. This thesis focuses on geometrical tolerancing, including form/orientation/ location tolerancing, and its integrated geometry information system. The main contributions are: Firstly, a global data expression for modelling the integration between the design and inspection process of a geometrical tolerance is presented based on category theory. The categorical data model represents, stores and manipulates all the elements and their relationships involved in design and inspection process of a geometrical tolerance, by categories, objects and morphisms, flexibly; the relationships between objects were refined by pull back structures; and the manipulations of the model such as query and closure of query are realized successfully by functor structures in category theory. Secondly, different categories of knowledge rules have been established to enhance the rationality and the intellectuality of the integrated geometry information system, such as the rules for the application of geometrical requirement, tolerance type, datum and datum reference framework and, for the refinement among geometrical specifications. Finally, the host system for drawing indication of geometrical tolerances in the framework of GPS was established based on AutoCAD 2007 using ObjectARX.