A Programming Language Approach to Parametric CAD Data Exchange

Author(s):  
John Altidor ◽  
Jack Wileden ◽  
Jeffrey McPherson ◽  
Ian Grosse ◽  
Sundar Krishnamurty ◽  
...  

Data exchange between different computer-aided design (CAD) systems is a major problem inhibiting information integration in collaborative engineering environments. Existing CAD data format standards such as STEP and IGES enable geometric data exchange. However, they ignore construction history, features, constraints, and other parametric-based CAD data. As a result, they are inadequate for supporting modification, extension and other important higher-level functionality when accessing an imported CAD model from another CAD system. Achieving such higher-level functionality therefore often requires a time-consuming, error-prone, tedious process of manually recreating the model in the target CAD system. Based on techniques adapted from programming language research, this paper presents an approach to exchanging parametric data between CAD systems using formally-defined conversion semantics. We have demonstrated the utility of our approach by developing a prototype implementation that automates the conversion of 2D sketches between two popular CAD systems: Pro/ENGINEER and SolidWorks. We present examples showing that our approach is able to accurately convert parametric CAD data even in cases where models were constructed using operations from the source CAD system that have no direct counterpart in the target CAD system. Although the case study focuses on 2D interoperability, our approach provides formal foundations for supporting 3D and semantic interoperability between CAD systems.

Author(s):  
Xun Xu

One of the key activities in any product design process is to develop a geometric model of the product from the conceptual ideas, which can then be augmented with further engineering information pertaining to the application area. For example, the geometric model of a design may be developed to include material and manufacturing information that can later be used in computer-aided process planning and manufacturing (CAPP/CAM) activities. A geometric model is also a must for any engineering analysis, such as finite elopement analysis (FEA). In mathematic terms, geometric modelling is concerned with defining geometric objects using computational geometry, which is often, represented through computer software or rather a geometric modelling kernel. Geometry may be defined with the help of a wire-frame model, surface model, or solid model. Geometric modelling has now become an integral part of any computer-aided design (CAD) system. In this chapter, various geometric modelling approaches, such as wire-frame, surface, and solid modelling will be discussed. Basic computational geometric methods for defining simple entities such as curves, surfaces, and solids are given. Concepts of parametric, variational, history-based, and history-free CAD systems are explained. These topics are discussed in this opening chapter because (a) CAD was the very first computer-aided technologies developed and (b) its related techniques and methods have been pervasive in the other related subjects like computer-aided manufacturing. This chapter only discusses CAD systems from the application point of view; CAD data formats and data exchange issues are covered in the second chapter.


Author(s):  
Bernie Bettig ◽  
Jami Shah

Abstract This paper describes the derivation of a consistent and comprehensive set of geometrical constraints for shape definition in Computer-Aided Design. These are needed to enable compatibility in parametric data exchange and to promote both standard capabilities and predictable solutions from constraint solving software kernels. The paper look at the mathematical basis for constraints present in the literature and elaborates about all types of constraints that can be described by the same mathematical basis. The approach considers all combinations of distance and angle constraints, on one point or all points of curves and surfaces, as well as transformations and mappings that are required in mechanical design.


2020 ◽  
Vol 7 (5) ◽  
pp. 603-614 ◽  
Author(s):  
Mutahar Safdar ◽  
Tahir Abbas Jauhar ◽  
Youngki Kim ◽  
Hanra Lee ◽  
Chiho Noh ◽  
...  

Abstract Feature-based translation of computer-aided design (CAD) models allows designers to preserve the modeling history as a series of modeling operations. Modeling operations or features contain information that is required to modify CAD models to create different variants. Conventional formats, including the standard for the exchange of product model data or the initial graphics exchange specification, cannot preserve design intent and only geometric models can be exchanged. As a result, it is not possible to modify these models after their exchange. Macro-parametric approach (MPA) is a method for exchanging feature-based CAD models among heterogeneous CAD systems. TransCAD, a CAD system for inter-CAD translation, is based on this approach. Translators based on MPA were implemented and tested for exchange between two commercial CAD systems. The issues found during the test rallies are reported and analyzed in this work. MPA can be further extended to remaining features and constraints for exchange between commercial CAD systems.


1998 ◽  
Vol 120 (09) ◽  
pp. 70-72
Author(s):  
Michael Henry

Walter Lorenz Surgical Inc., Jacksonville, FL, specializes in the medical devices known as rigid fixation implants. Lorenz Surgical was purchased by Biomet Inc. of Warsaw, Indiana in the year 1992, which resulted in Lorenzo owning two computer-aided design (CAD) systems. In 1996, with the completion of Lorenz Surgical's new manufacturing facility in Jacksonville, all Lorenz operations were transferred back to Florida, including all the manufacturing equipment and its three seats of Unigraphics, which by then were running on Windows NT workstations. The company's management feels it could have stayed with Unigraphics and accomplished its goals, but that adding Solid Edge was a good move. It gave Lorenz flexibility in hiring, allowed it to buy more CAD seats than it could have if it had stayed with Unigraphics alone, and provided a very productive tool. Lorenz's surgical instruments are currently designed exclusively in Solid Edge. Instruments can be modeled in either CAD system, but the job goes faster in Solid Edge. The creators of Solid Edge put a lot of effort into usability, and this shows in how few mouse clicks are needed for common operations. Products that have many standard features, such as a screwdriver consisting of m any cylinders, are very quickly modeled in Solid Edge.


2006 ◽  
Vol 6 (3) ◽  
pp. 308-314 ◽  
Author(s):  
Duhwan Mun ◽  
Heungki Kim ◽  
Kwangsub Jang ◽  
Junmyun Cho ◽  
Junhwan Kim ◽  
...  

Reusing existing design models and utilizing an e-Catalog for components are required for faster product development. For the acceleration, an e-Catalog should provide parametric computer aided design (CAD) models, since parametric information is necessary for configuration design. There are difficulties, however, in building a parametric library of all the necessary combinations using a CAD system, because there are too many component combinations for each product. To overcome this problem, we propose a table parametric method to generate parametric CAD models automatically, and describe its details.


Author(s):  
Владимир Гусев ◽  
Vladimir Gusev ◽  
Елена Савина ◽  
Elena Savina

A high-performance and accurate machining of complex special surfaces with the aid of NC equipment at the simultaneous use of four and more controlled coordinate axes is impossible without application of modern CAD systems and post-processors. Functional potentialities and a methodology for the design of complex surface machining in a "flange" part in modern CAD Esprit system are considered. Control commands are described the realization of which ensures a procedure for a computer aided design of technology, the development of a control program and simulation of operation motions of working units in a lathe. The simulation of profile surface turning is described in an intelligible way which is particularly significant for the comprehension and use of material presented.


Author(s):  
Yuchu Qin ◽  
Wenlong Lu ◽  
Qunfen Qi ◽  
Xiaojun Liu ◽  
Yanru Zhong ◽  
...  

Exchanging computer-aided design (CAD) model data among heterogeneous CAD systems is indispensable for collaborative product development. Currently, the industry mainly uses the standardized neutral files-based methods to implement such exchange. While at the same time, the application of web ontology language (OWL) file and underlying semantic web technologies in CAD model data exchange is gaining importance and popularity within the academia. The coexistence of different types of methods has generated a series of controversies and questions within the industry and the academia. Yet, can the neutral files-based exchange methods completely implement model data exchange among heterogeneous CAD systems? What challenges have been addressed to date by the developed CAD model data exchange standards? Why OWL has been introduced to CAD model data exchange? Does CAD model data exchange really need OWL? Are there any issues in existing neutral files-based exchange methods and OWL file-based exchange methods need to be addressed in future studies? This paper proposes to conduct a study of the standardized neutral files-based exchange methods and OWL file-based exchange methods. An in-depth analysis of the widely used standard for the exchange of product model data (STEP) method and the newly emerging OWL methods is first provided. Then, the paper makes a detailed comparison between these two types of methods based on this analysis. Finally, some issues in the two types of methods that need to be addressed in the future are discussed.


2005 ◽  
Vol 5 (3) ◽  
pp. 182-187 ◽  
Author(s):  
Christoph M. Hoffmann

Computer-aided design (CAD) systems have become parametric, basing shape design on constraints and design feature operations. We review the development of constraint-based parametric CAD, explaining some of the foundational issues as well as giving an outlook on possible future directions of development.


Author(s):  
Weihang Zhu

This paper presents an infrastructure that integrates a haptic interface into a mainstream computer-aided design (CAD) system. A haptic interface, by providing force feedback in human-computer interaction, can improve the working efficiency of CAD/computer-aided manufacturing (CAM) systems in a unique way. The full potential of the haptic technology is best realized when it is integrated effectively into the product development environment and process. For large manufacturing companies this means integration into a commercial CAD system (Stewart, et al., 1997, “Direct Integration of Haptic User Interface in CAD Systems,” ASME Dyn. Syst. Control Div., 61, pp. 93–99). Mainstream CAD systems typically use constructive solid geometry (CSG) and boundary representation (B-Rep) format as their native format, while internally they automatically maintain triangulated meshes for graphics display and for numerical evaluation tasks such as surface-surface intersection. In this paper, we propose to render a point-based haptic force feedback by leveraging built-in functions of the CAD systems. The burden of collision detection and haptic rendering computation is alleviated by using bounding spheres and an OpenGL feedback buffer. The major contribution of this paper is that we developed a sound structure and methodology for haptic interaction with native CAD models inside mainstream CAD systems. We did so by analyzing CAD application models and by examining haptic rendering algorithms. The technique enables the user to directly touch and manipulate native 3D CAD models in mainstream CAD systems with force/touch feedback. It lays the foundation for future tasks such as direct CAD model modification, dynamic simulation, and virtual assembly with the aid of a haptic interface. Hence, by integrating a haptic interface directly with mainstream CAD systems, the powerful built-in functions of CAD systems can be leveraged and enhanced to realize more agile 3D CAD design and evaluation.


TEM Journal ◽  
2020 ◽  
pp. 1141-1149
Author(s):  
Alexey L. Khoroshko

In this paper there are examples showing that AutoCAD (computer-aided design (CAD)) was and still is a powerful tool for technical graphics. Since Autodesk is a pioneer in the market of commercial widely available CAD systems, in this company CAD principles (which can be used by relatively unprepared users), nature and volume of teams, sequence and features of their implementation were developed. Despite the fact that today AutoCAD is only one of many packages, and its use as a training program guarantees not only high-quality training of specialists, but also the fact that the employee can easily switch to another CAD system, intuitively understanding the principles of function. In terms of technical performance, AutoCAD is a complete tool covering the entire spectrum of functions in the field of "Engineering and Computer Graphics" course.


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