Conversions of Feature-Based Design Representations Using Graph Grammar Parsing

1994 ◽  
Vol 116 (3) ◽  
pp. 785-792 ◽  
Author(s):  
D. W. Rosen ◽  
J. R. Dixon ◽  
S. Finger
Keyword(s):  
Cost Evaluation ◽  
Graph Grammar ◽  
Manufacturing Cost ◽  
Graph Grammars ◽  
Design Features ◽  
Feature Based ◽  
Design Representations ◽  
Secondary Feature ◽  
Feature Based Design ◽  
Tool Cost

In order to trade off required functionality with manufacturing, cost, and other life-cycle considerations, it is necessary to evaluate designs in these secondary view-points. Representations of mechanical components designed with design features must be converted into representations containing relevant secondary viewpoint features. When describing a design verbally, designers often use languages of design features. In other viewpoints, different languages of viewpoint-specific features are used. Thus, translation capability between viewpoint languages is needed to convert from one representation to another. The approach taken here is to use formal graph grammars to define the feature-based design of thin-walled components and the secondary feature languages. Features are defined by graphs that explicitly represent the feature, its geometric entities, and their connectivity. Components are built up by combining feature graphs based on designer specified feature connectivity. To convert from the design to a secondary viewpoint, a three-step process is used where the last step is parsing by a grammar from the secondary viewpoint. To illustrate the conversion process, a converter for tool cost evaluation in injection molding and die casting is developed and applied to an example component.

Efficient Converters for Feature-Based Mechanical Component Representations

1993 ◽  
Author(s):  
David W. Rosen
Keyword(s):  
Die Casting ◽  
Graph Isomorphism ◽  
Cost Evaluation ◽  
Graph Grammar ◽  
Graph Grammars ◽  
Paper Manufacturing ◽  
Feature Based ◽  
Design Representations ◽  
Thin Walled ◽  
Manufacturing Features

Abstract To enable the development of design-for-manufacturability tools for thin-walled mechanical components, converters are needed to convert design representations of components into representations with which manufacturability evaluations can be performed. In our work components are designed with features and represented as graphs. Conversely, manufacturing representations consist of manufacturing features, that in general are different than design features. Thus, the problem of converting feature-based representations arises. In this paper, manufacturing features are defined using graph grammars which provide a general, formal, structured description of how to convert features. Unfortunately, using graph grammar parsing as the basis for conversion is not computationally viable due to the nature of graph isomorphism determination. By taking advantage of the known structure of design representations and of manufacturing features, and by utilizing AI techniques for efficient pattern-matchers, it is shown that efficient converters can be constructed that do not require graph isomorphism determination. Conditions are given for the construction of polynomial time converters and a general conversion module is presented. An example converter is illustrated for tooling cost evaluation in injection molding and die casting.

Purely Declarative Feature-Based Design With Feature Type Property Maintenance

2004 ◽  
Author(s):  
Dhaval Lokagariwar ◽  
Bernhard Bettig
Keyword(s):  
Design Process ◽  
Research Work ◽  
Building Blocks ◽  
Feature Representation ◽  
Software Systems ◽  
Design Environment ◽  
Design Features ◽  
Planning Algorithm ◽  
Feature Based ◽  
Feature Based Design

Commercial feature-based design systems are based on describing the design model in some form of sequential representation of primitive shapes and operations called features. In these systems, the overall design process, the behavior of building blocks and the characteristics of the final model, are governed by the construction sequence. These systems do not check for the conformity of the final shape with the actual design intent of features, and allow their design and engineering intent to be altered during the design process. The research work presented here describes a new design methodology and feature representation for facilitating a design environment that is independent of any construction order or constraint-based dependencies and provides a mechanism for maintaining design and engineering intent of the design features. The methodology works by dynamically evaluating the features using a planning algorithm such that the validity of each feature is maintained. These are intended to serve as a generic template that can be used to design and develop specific design features and CAD software systems.

Features and Algorithms for Tooling Cost Evaluation in Injection Molding and Die Casting

1992 ◽  
Author(s):  
David W. Rosen ◽  
John R. Dixon ◽  
Corrado Poli ◽  
Xin Dong
Keyword(s):  
Die Casting ◽  
Cost Evaluation ◽  
Design System ◽  
Cost Drivers ◽  
Die Cast ◽  
Feature Based ◽  
Injection Molded ◽  
Feature Based Design ◽  
The Cost ◽  
Feature Conversion

Abstract Design-for-manufacturability tools for thin-walled mechanical components are being developed and integrated into a feature-based design system. This paper presents recent work on automatically evaluating injection molded and die cast components for tooling cost. The methodology for evaluation is to convert a design features representation of a component into a tooling cost features representation, then compute cost drivers from the features. Evaluation can be done directly from the cost drivers using cost data in tables. The critical tooling cost features were derived from tooling cost drivers reported in previous work. The tooling cost features and cost drivers are listed, and definitions and algorithms for conversion from design-with to tooling cost features are given. At the end, conclusions are drawn on the feasibility of feature conversion and feature-based tooling cost evaluation, based on the design-with features approach.

Representing and Recognizing Features in Mechanical Designs

1990 ◽  
Author(s):  
Susan Finger ◽  
Scott A. Safier
Keyword(s):  
Graph Grammars ◽  
Design Environment ◽  
Geometric Models ◽  
Feature Based ◽  
Geometric Representations ◽  
Design Systems ◽  
High Level ◽  
Feature Based Design ◽  
Structural Engineers ◽  
Rough Surface Finish

Abstract When experts view an object, they perceive it in terms of their own expertise. For example, manufacturers see features that affect the processes used to fabricate a part, while structural engineers see sources of stresses and other features that tend to reduce the life of a part. Features can be geometric, such as slots or chamfers; they can be quantitative, such as distances between holes; they can be functional, such as alignment; or they can be qualitative, such as a rough surface finish. Research in feature-based design systems for mechanical designers has been motivated by the realization that geometric models represent the design in greater detail than can be utilized by designers, process planners, assembly planners, or by systems that emulate these activities. Features provide abstractions to facilitate the creation, representation, and analysis of designs. Our goal is to enable designers to compose mechanical designs from high-level features that embody functional and geometric properties. In addition, we want to provide designers with feedback on the manufacturability, assemblability, functionality, cost, etc. of the design as it evolves. To support this process in an intelligent CAD environment requires the integration of geometric models, analysis tools, and synthesis tools so that all aspects of the design can be considered while it is in progress. We are developing a design environment based on a shared representation of the design in which we can extract and reason about features of the design from different perspectives. Our approach is to represent both the design and the features using graph grammars. By representing the features using the same grammar as the design, we can recognize features by parsing a feature against the graph that represents the design. We are exploring grammars for behavior as well as geometry in order to provide a link between behavioral and geometric representations. In this paper, we focus on the representation and recognition of features.

SINFONIA: An Open Feature-Based Design Module

1994 ◽  
Author(s):  
J. Ovtcharova ◽  
S. Haßinger ◽  
A. S. Vieira ◽  
U. Jasnoch ◽  
J. Rix
Keyword(s):  
Shape Representation ◽  
Design Feature ◽  
Modular Architecture ◽  
Design Environment ◽  
Design Features ◽  
Cad System ◽  
Feature Based ◽  
Definition Of ◽  
Feature Based Design ◽  
Solid Modeler

Abstract Sinfonia is a module for feature-based design which is configurable to users and applications within diverse CAD environments, particularly in the area of mechanical engineering. Sinfonia has an open and modular architecture that allows to modify and extend existing functionalities, and to integrate new modeling facilities and application tasks. This module enables the users to work with standard pre-defined design features delivered with the module, or to define dynamically their own specific design features during the design session. Furthermore, Sinfonia allows the interactive definition of constraints concerning the product semantics. Definition and administration of constraints in feature-based models provided by a consistency manager is supported to reach semantical correctness of the part models. The main modules of Sinfonia are the Feature Modeler and the Design Feature Manager. The Feature Modeler is responsible for the instantiation of features and the creation of the feature-based model. The Design Feature Manager allows feature data and design processes to be managed in a uniform way. The CAD system environment in which Sinfonia is integrated consists of the following modules: the User Interface System and the Application modules (offering tools for interaction of the user with application specific part models and for communication with external systems and applications, such as NC modules, etc.), the Solid Modeler (responsible for creating the shape representation of the feature-based model), the Consistency Manager (providing services to handle all kinds of different constraints within the design environment) and the Product Database which includes all services for storing and retrieving various product data.

Instantiation and Manipulation of User-Defined Freeform Features

2008 ◽  
Author(s):  
Thomas R. Langerak
Keyword(s):  
Design Process ◽  
Current Literature ◽  
Design Features ◽  
Shape Model ◽  
Target Shape ◽  
General Methodology ◽  
Feature Based ◽  
Definition Of ◽  
High Level ◽  
Feature Based Design

One of the sub-topics of CAD research is the topic of feature-based design. Features are characteristic parts of a shape to which functional or parameter information can be attached. By using features in a design process, high-level interrogation and editing of a shape model is enabled. It is widely accepted that feature-based design methods should be able to handle user-defined features. Much work has been done on the definition of features and the management of feature definitions, but very little work has been done on the instantiation of these features on a target shape, especially in the domain of freeform shape. This paper discusses the current literature on freeform feature-based design and identifies the issues that play a role in the instantiation and manipulation of freeform features on target shapes. Also, a general methodology is proposed for the instantiation and manipulation of freeform features. Finally, an implementation of the proposed methods and some application examples are given.

scholarly journals An Automated Approach to Feature-Based Design for Reusable Parameter-Rich Surface Models

2007 ◽  
Vol 4 (1-4) ◽  
pp. 497-507
Author(s):  
Jason H. Elliott ◽  
Courtney L Berglund ◽  
C. Greg Jensen
Keyword(s):  
Surface Models ◽  
Feature Based ◽  
Feature Based Design

Converting metamodels to graph grammars: doing without advanced graph grammar features

2013 ◽  
Vol 14 (3) ◽  
pp. 1297-1317 ◽  
Author(s):  
Luka Fürst ◽  
Marjan Mernik ◽  
Viljan Mahnič
Keyword(s):  
Graph Grammar ◽  
Graph Grammars

Geometric Reasoning Based on Graph Grammar Parsing

1994 ◽  
Vol 116 (3) ◽  
pp. 763-769 ◽  
Author(s):  
Z. Fu ◽  
A. de Pennington
Keyword(s):  
Intelligent Design ◽  
Feature Recognition ◽  
Geometric Reasoning ◽  
Geometric Constraints ◽  
Graph Grammar ◽  
Feature Interaction ◽  
Knowledge Based ◽  
Feature Based ◽  
Feature Information ◽  
And Performance

It has been recognized that future intelligent design support environments need to reason about the geometry of products and to evaluate product functionality and performance against given constraints. A first step towards this goal is to provide a more robust information model which directly relates to design functionality or manufacturing characteristics, on which reasoning can be carried out. This has motivated research on feature-based modelling and reasoning. In this paper, an approach is presented to geometric reasoning based on graph grammar parsing. Our approach is presented to geometric reasoning based on graph grammar parsing. Our work combines methodologies from both design by features and feature recognition. A graph grammar is used to represent and manipulate features and geometric constraints. Geometric constraints are used within symbolical definitions of features constraints. Geometric constraints are used within symbolical definitions of features and also to define relative position and orientation of features. The graph grammar parsing is incorporated with knowledge-based inference to derive feature information and propagate constraints. This approach can be used for the transformation of feature information and to deal with feature interaction.

Assembly modeling as an extension of feature-based design

1993 ◽  
Vol 5 (3-4) ◽  
pp. 218-237 ◽  
Author(s):  
Jami J. Shah ◽  
Mary T. Rogers
Keyword(s):  
Assembly Modeling ◽  
Feature Based ◽  
Feature Based Design
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