Feature based hex meshing methodology: feature recognition and volume decomposition

2001 ◽  
Vol 33 (3) ◽  
pp. 221-232 ◽  
Author(s):  
Y. Lu ◽  
R. Gadh ◽  
T.J. Tautges
Keyword(s):  
Feature Recognition ◽  
Volume Decomposition ◽  
Feature Based

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.

Feature-Based Machining Precedence Reasoning and Sequence Planning

1998 ◽  
Author(s):  
Yong Se Kim ◽  
Eric Wang ◽  
Choong Soo Lee ◽  
Hyung Min Rho
Keyword(s):  
Feature Recognition ◽  
Search Space ◽  
Machining Process ◽  
Planning System ◽  
Process Information ◽  
Computer Aided Process Planning ◽  
Sequence Planning ◽  
Precedence Relations ◽  
Feature Based ◽  
Form Features

Abstract This paper presents a feature-based method to support machining sequence planning. Precedence relations among machining operations are systematically generated based on geometric information, tolerance specifications, and machining expertise. The feature recognition method using Alternating Sum of Volumes With Partitioning (ASVP) Decomposition is applied to obtain a Form Feature Decomposition (FFD) of a part model. Form features are classified into a taxonomy of atomic machining features, to which machining process information has been associated. Geometry-based precedence relations between features are systematically generated using the face dependency information obtained by ASVP Decomposition and the features’ associated machining process information. Multiple sets of precedence relations are generated as alternative precedence trees, based on the feature types and machining process considerations. These precedence trees are further enhanced with precedence relations from tolerance specifications and machining expertise. Machining sequence planning is performed for each of these precedence trees, applying a matrix-based method to reduce the search space while minimizing the number of tool changes. The precedence trees may then be evaluated based on machining cost and other criteria. The precedence reasoning module and operation sequence planning module are currently being implemented within a comprehensive Computer-Aided Process Planning system.

Heuristics Based Feature Recognition: A Graph Approach

1994 ◽  
Author(s):  
Shyam V. Narayan ◽  
Zhi-Kui Ling
Keyword(s):  
Engineering Design ◽  
Surface Finish ◽  
Feature Recognition ◽  
Graph Representation ◽  
Heuristic Rules ◽  
Feature Identification ◽  
Design And Manufacturing ◽  
Feature Based ◽  
Manufacturing Features

Abstract Feature based modeling has been used as a means to bridge the gap between engineering design and manufacturing. Features can represent an artifact with higher level entities which relate directly to its design functionalities and manufacturing characteristics, such as surface finish, manufacturability, fits, tolerance etc. In this study, a heuristic based feature recognition approach is proposed by using the graph representation of a design. The process consists of two steps: subgraph construction, and subgraph to feature identification. In this study, the subgraph construction is accomplished by using a set of heuristic rules. The process of subgraph to feature identification is carried out with a set of integers and characters which represent the geometric, topological, and semantic characteristics of the corresponding feature. This feature recognition scheme is used for the identification of machine features in a design.

Form Feature Recognition Using Base Volume Decomposition

1994 ◽  
Author(s):  
James K. Coles ◽  
Richard H. Crawford ◽  
Kristin L. Wood
Keyword(s):  
Real World ◽  
Feature Recognition ◽  
Recognition Method ◽  
Mechanical Parts ◽  
Feature Representations ◽  
Volume Decomposition ◽  
Boundary Representations ◽  
New Feature ◽  
Form Feature

Abstract A new feature recognition method is presented that generates volumetric feature representations from conventional boundary representations of mechanical parts. Recognition is accomplished by decomposing the known total feature volume of a part into a set of smaller volumes through analytic face extension. The decomposed volumes are combined to generate an initial set of features. Alternative sets of features are generated by maintaining and evaluating information on intersections of the initial feature set. The capabilities of the method are demonstrated through both a hypothetical and a real world design example. The method’s ability to locate features despite interactions with other features, and its ability to generate alternative sets of features, distinguishes it from existing recognition techniques.

Maximal Volume Decomposition and its Application to Feature Recognition

1995 ◽  
Author(s):  
Parag Dave ◽  
Hiroshi Sakurai
Keyword(s):  
Decomposition Method ◽  
Feature Recognition ◽  
Graph Matching ◽  
Raw Material ◽  
Maximal Volume ◽  
Object A ◽  
Finished Part ◽  
Volume Decomposition ◽  
Minimal Cells ◽  
Volume Difference

Abstract A method has been developed that decomposes an object having both planar and curved faces into volumes, called maximal volumes, using the halfspaces of the object. A maximal volume has as few concave edges as possible without introducing additional halfspaces. The object is first decomposed into minimal cells by extending the faces of the object. These minimal cells are then composed to form maximal volumes. The combinations of such minimal cells that result in maximal volumes are searched efficiently by examining the relationships among those minimal cells. With this decomposition method, a delta volume, which is the volume difference between the raw material and the finished part, is decomposed into maximal volumes. By subtracting maximal volumes from each other in different orders and applying graph matching to the resulting volumes, multiple interpretations of features can be generated.

N-Rep: A Neutral Feature Representation to Support Feature Mapping and Data Exchange Across Applications

2004 ◽  
Author(s):  
Madhu S. Medichalam ◽  
Jami J. Shah ◽  
Roshan D’Souza
Keyword(s):  
Data Exchange ◽  
Feature Recognition ◽  
Data Transfer ◽  
Feature Representation ◽  
Declarative Language ◽  
Feature Mapping ◽  
Topological Relationships ◽  
Feature Based ◽  
Parametric Relationships ◽  
Exchange Medium

The proliferation of different feature based systems has made feature data exchange an important issue. Unlike geometry data exchange, where different representations use the same fundamental concepts; the most popular being B-Rep and CSG [Shah et al. 88], different feature representation schemes use different concepts to represent features corresponding to the application and domain. Therefore, feature data transfer between applications not only involves transfer of instance data but also transformation of feature concepts. This paper presents N-Rep, an application independent declarative language, for feature definition that includes topology, topological relationships, geometry, geometric relationships, parameters and parametric relationships. N-Rep has been designed to serve three roles, viz., (a) to generate feature recognition algorithms for recognizing features from geometry, (b) to generate feature producing procedures to be used in design by feature approaches, and (c) to serve as a neutral feature data exchange medium between representations.

A Feature-Based Section Curve Reconstructing Strategy

2013 ◽  
Vol 572 ◽  
pp. 155-158
Author(s):  
Hai Tao Zhu ◽  
Liang Cong
Keyword(s):  
Error Analysis ◽  
Point Cloud ◽  
Feature Recognition ◽  
Point Cloud Data ◽  
Curve Segment ◽  
Cloud Data ◽  
Modeling Process ◽  
Feature Based ◽  
Section Curve ◽  
2D To 3D

ntegrating section feature recognition with forward design is an effective method to reconstruct section curve and change feature architecture patterns from 2D to 3D. This paper proposes solutions to filter the points on the slices of point cloud data, automatically sequence the points on slices, recognize section curve feature, fit each curve segment and reconstruct section curves. All the relevant algorithms are implemented in Matlab. The point cloud data of sighting scope is used to validate the strategy. Also, Error analysis is carried out in Geomagic Studio. This strategy proves its feasibility and accuracy of completing reverse modeling process.

Research on Feature-Based Rapid Programming for Aircraft NC Parts

2007 ◽  
Vol 10-12 ◽  
pp. 682-687 ◽  
Author(s):  
Ying Guang Li ◽  
T.L. Fang ◽  
S.J. Cheng ◽  
W.H. Liao
Keyword(s):  
Feature Recognition ◽  
Tool Path ◽  
Data Transfer ◽  
Tool Path Generation ◽  
Path Generation ◽  
Transfer Standard ◽  
Manufacturing Enterprises ◽  
Nc Programming ◽  
Feature Based

Feature-based programming is one of tendency of NC programming technology, and it is also an important portion for CAD/CAPP/CAM integration in the manufacturing enterprises. Because of selecting geometry repeatedly, random programming and bad integration during programming for the aircraft NC parts, the technology of rapid programming based on features is put forward in this paper. On the basis of features, the technology of feature recognition for aircraft NC parts and the algorithm of tool path generation based on features are integrated by taking XML as data transfer standard. With this method, the programming for aircraft NC parts can be realized quickly in the condition of CAD/CAPP/CAM integration. The system developed has been well applied to the programming for aircraft NC parts in an aircraft corporation.

Sign in / Sign up

Export Citation Format

Share Document