A reference kernel model for feature-based CAD systems supported by conditional attributed rewrite systems (original) (raw)

Reflective control of attributed entities in feature-based CAD systems using a CARW system manager

IFIP Advances in Information and Communication Technology, 1996

Requirements, necessary to integrate intelligent computer-aided design systems in future KAE/CAM systems, aimed to support concurrent engineering and the handling of product data, propound extensions and new developments of system architecture, data structures, and functionality. Indispensable among them are an integrated and flexible formalization of the knowledge base and a modular system architecture, which can be easily modified according to current demands. Within our developed framework we propose a homogeneous representation of declarative, procedural, and control knowledge, based on a conditional attributed rewriting system (CARW). Design, reasoning, and computation are carried out in domains of typed attributed entities, which are replenished with reflective capabilities. Due to the rule-based approach, a high degree of flexibility and modularity can be achieved, while perpetuating the system's overall control in form of a CARW manager. Objective of given study is to investigate in how far our taken approach satisfies considered requirements. Of major interest are, within given scope, consistency aspects among attributed entities of different domains and the use of reflective techniques to support status evaluation of design form features, their operators as well as design strategies.

Towards generic representations of designs formalised as Features

Feature-Based Modelling (FBM) is an information modelling technique that allows the formalisation of design concepts and using these formal definitions in design modelling. The dynamic nature of design and design information calls for a specialised approach to FBM that takes into account flexibility and extensibility of Feature Models of designs. Research work in Eindhoven has led to a FBM framework and implementation that can be used to support design.. Feature models of a design process has demonstrated the feasibility of using this information modelling technique. To develop the work on FBM in design, three tracks are initiated: Feature model descriptions of design processes, automated generic representation recognition in graphic representations, and Feature models of generic representations. The paper shows the status of the work in the first two tracks, and present the results of the research work.

AN INVESTIGATION OF INTEGRATING DESIGN BY FEATURES AND FEATURE RECOGNITION

2000

Feature technology has been evolving since the early 1980s, yet is still found in few commercial CAD systems. Traditional CAD systems provide support for geometric design and limited parametric design. Two basic approaches to feature modeling have been developed: design by features and feature recognition. Each of these methods provide specific tools to designers not provided in traditional CAD. A truly comprehensive system ought to integrate the advances in geometric modeling, parametric modeling, design by features, and feature recognition. A brief review of existing integrated systems is provided. Geometric representations, feature representations, and model integration schemes are discussed. Finally, a discussion of the issues involved with developing an integrated system is provided. These issues evolved from the development of such as system.

A framework for feature-based representation of the design process

Engineering with Computers, 1990

The design process is very complicated and differs with each engineer. The development of computer-based aids for design must take this into consideration and allow for the nuances of the individual. A generic representation of the information used in design is required for the development of any data base that supports the design aid. A properly designed data base or set of data bases can help integrate CAD, expert system, and ancillary programs, thereby forming an intelligent design system. A model has been developed that allows the information requirements of the design process to be analyzed. A data base for an intelligent design system can be developed based on these results.

Design Database Modeling for the Future CAD Systems

To develop the future CAD systems with concurrent engineering functions, a new CAD model, called Concurrent Engineering-oriented Design Database Representation Model (CE-DDRM), is introduced in this research for supporting various lifecycle aspects in concurrent design. In this model, concepts and behaviors of different design database modeling components, including entities, properties, relationships, tasks, and specifications, are defined at meta-class level. Design database is modeled at two different levels, class level and instance level, representing generic design libraries and special design cases, respectively.

A data structure for a generic design model

IFIP Advances in Information and Communication Technology, 1996

Modern CAD systems need to be enriched by knowledge about the design process for classes of artifacts of a given design domain. This paper presents a generic model to capture knowledge about the product and its design process. This integrated model is made of a process model, describing the sequence of design tasks and states, and a product model, describing features of the product from different points of view.

CAD/CAPP Integration using Feature Ontology

Concurrent Engineering: Research and Applications, 2007

In a collaborative computer-supported engineering environment, the interoperation of various applications will need a representation that goes beyond the current geometry-based representation, which is inadequate for capturing semantic information. The primary purpose of this paper is to discuss a semantically-based information exchange protocol that will facilitate seamless interoperability among current and next generation computeraided design systems (CAD) and between CAD and other systems that use product data.

A concept for a constraint-based representation of functional and geometric design knowledge

Proceedings of the first ACM symposium on Solid modeling foundations and CAD/CAM applications - SMA '91, 1991

Pure geometric modeling systems are effective as drafting tools, but of limited utility in conceptual design. A design system which explicitly represents functional requirements and ties this to a geometric model could more effectively support the design process and provide a richer database to be used by production planning and design optimization tools. To achieve this goal more flexible ways of structuring geometric knowledge are needed. This paper describes the basic ideas behind a feature-oriented functional design system currently under study. Geometry is represented through a hierarchy of geometrical structures called geornes each of which represent some underconstrained set of geometrical elements. Models are represented by a constraint network that is generated by the instantiation and unification of geomes. Possible methods for providing a graphical user interface to this type of system are also briefly discussed.

A definitive programming approach to the implementation of CAD software

Intelligent CAD systems II: …, 1989

This paper outlines an approach to the implementation of CAD systems that makes use of a programming paradigm based upon definitions ("definitive programming"). It departs from previous research on "pure definitive notations" - special-purpose notations for interaction - and proposes a general-purpose programming model based upon definitive principles. This model is examined as a possible basis for the development of an integrated framework within which to address the broader issues of a design support environment, including constraint handling and user-interface management. This gives a new perspective on the use of definitive principles for interaction in which the emphasis is upon interpreting a family of definitions as one of many possible "intelligent views" of an interactive system. It also establishes a closer relationship between the definitive programming approach to CAD and the study of CAD from an AI perspective than was previously evident. The design of an appropriate definitive notation for geometric modelling is a fundamental aspect of the application of definitive principles to CAD software. An appropriate basis for such a notation is presented in an Appendix.

Enhancement of CAD model interoperability based on feature ontology

As the networks connect the world, enterprises tend to move manufacturing activities into virtual spaces. Since different software applications use different data terminology, it becomes a problem to interoperate, interchange, and manage electronic data among heterogeneous systems. According to RTI, approximately one billion dollar has been being spent yearly for product data exchange and interoperability. As commercial CAD systems have brought in the concept of design feature for the sake of interoperability, terminologies of design features need to be harmonized. In order to define design feature terminology for integration, knowledge about feature definitions of different CAD systems should be considered. STEP standard have attempted to solve this problem, but it defines only syntactic data representation so that semantic data integration is not possible. This paper proposes a methodology for integrating modeling features of CAD systems. We utilize the ontology concept to build a data model of design features which can be a semantic standard of feature definitions of CAD systems. Using feature ontology, we implement an integrated virtual database and a simple system which searches and edits design features in a semantic way.