A new solid modeling system for CAD/CAM integration through engineering drawing understanding
Abstract
A solid model is crucial for CAD/CAM integration. However, for supporting downstream CAD/CAM applications, a solid model should be able to represent not only the basic shape of a mechanical part but also all the design intentions designers may have. Without these design intentions being properly represented, the solid model cannot properly support applications such as process planning, inspection, and assembly. In addition to the representation of design intentions, the solid model construction process should be consistent with mechanical design process; otherwise, the solid model input will be difficult and time consuming, which is a problem with almost all the existing solid modeling systems. In this research, a framework of a new solid modeling system which can represent some design intentions and can be constructed through the scheme of engineering drawing is proposed. This framework includes three parts: a variational solid model, V-SOLID, an engineering drawing based design model, ED-DESIGN, and a knowledge-based computer understanding system. The V-SOLID is an augmented version of the existing boundary representation which is able to represent dimension, tolerance, datum structure, surface attributes and geometric relationships among surfaces. The ED-DESIGN is an input scheme which allows the designer to input the V-SOLID through the scheme of engineering drawing. Also, in this ED-DESIGN, an engineering drawing is represented in a drawing space instead of a drawing plane, so that engineering drawing can be interpreted as a pseudo-3D design scheme. The computer understanding system is developed to construct the V-SOLID from the ED-DESIGN using a knowledge-based approach. This approach can handle a larger domain than the previous approaches of solid construction based on projections. Using this framework of solid modeling system, a smooth transition from the traditional manufacturing environment to the CIM environment can be expected.
Degree
Ph.D.
Advisors
Liu, Purdue University.
Subject Area
Electrical engineering
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