Feature Interactions

2009 ◽  
pp. 109-125
Author(s):  
Xun Xu
Keyword(s):  
Feature Recognition ◽  
Basic Feature ◽  
Feature Model ◽  
Design System ◽  
Feature Interaction ◽  
Complete Suppression ◽  
Feature Interactions ◽  
Feature Based ◽  
The One ◽  
Feature Based Design

Feature interaction tends to have a wide range of consequences and effects on a feature model and its applications. While these may often be intended, it is also true that feature validity can be violated, one way or another, by feature interactions (Shah & Mäntylä, 1995, Gao & Shah, 1998, Lee & Kim, 1998). They may affect the semantics of a feature, ranging from slight changes in actual parameter values, to some substantial alterations to both geometry and topology or even complete suppression of its contribution to the model shape. To certain extent, successful applications of feature recognition and feature-based techniques have been hindered by interactions among the features. Feature interaction was first studied in relation to feature recognition systems. As an alternative to feature recognition, feature-based design methodology has also become prevalent in recent years. Although a number of successful and commercially available feature-based design systems have been reported, current CAD technology is still unable to provide an effective solution for fully handling the complexity of feature interactions. Very often in a feature-based design system, the interaction between two features gives rise to an unintended feature, nullifying the one-to-one mapping from design features to manufacturing features. The resulting manufacturing feature is usually of a form that the system cannot handle or represent. Thus feature interaction resolution is equally essential for a feature-based design system (Dereli & Baykasoglu, 2004). As discussed in Chapter IV, features can be represented either as a set of faces or as a volume. The interactions between surface features are different from those occurring between volumetric features. This chapter discusses different types of interactions that arise from these two feature representation schemes and uses the interacting entities to classify them. There are two types of surface feature interactions, basic feature interaction and complex feature interaction. Three types of basic feature interactions are discussed. They are nested, overlapping, and intersecting types. Interacting patches are used to classify volumetric feature interactions. These interacting patches can be of a containing, contained, or overlapping type. The significance of feature interactions lies in their effect on the machining sequence of the features involved. This is also discussed in this chapter. When features are close to each other but do not share any geometric entities, interactions may also happen for structural reasons. This type of feature interaction can be called interaction by vicinity. The main aim of this chapter is to take a holistic approach toward feature interaction solutions. The example parts used are from the “Catalogue of the NIST (National Institute of Standards and Technology) Design, Planning and Assembly Repository” (Regli & Gaines, 1996). A case study is provided in the end of the chapter.

Feature Recognition

2009 ◽  
pp. 90-108
Author(s):  
Xun Xu
Keyword(s):  
Feature Recognition ◽  
Geometric Model ◽  
Feature Model ◽  
Design System ◽  
Cad System ◽  
Domain Specific ◽  
Cad Models ◽  
Feature Based ◽  
High Level ◽  
Feature Based Design

Conventional CAD models only provide pure geometry and topology for mechanical designs such as vertices, edges, faces, simple primitives, and the relationship among them. Feature recognition is then required to interpret this low-level part information into high-level and domain-specific features such as machining features. Over the years, CAD has been undergoing fundamental changes toward the direction of feature-based design or design by features. Commercial implementations of FBD technique became available in the late 1980’s. One of the main benefits of adopting feature- based approach is the fact that features can convey and encapsulate designers’ intents in a natural way. In other words, the initial design can be synthesized quickly from the high-level entities and their relations, which a conventional CAD modeller is incapable of doing. However, such a feature-based design system, though capable of generating feature models as its end result, lacks the necessary link to a CAPP system, simply because the design features do not always carry the manufacturing information which is essential for process planning activities. This type of domain-dependent nature has been elaborated on in the previous chapter. In essence, feature recognition has become the first task of a CAPP system. It serves as an automatic and intelligent interpreter to link CAD with CAM, regardless of the CAD output being a pure geometric model or a feature model from a FBD system. To be specific, the goal of feature recognition systems is to bridge the gap between a CAD database and a CAPP system by automatically recognizing features of a part from the data stored in the CAD system, and based on the recognized features, to drive the CAPP system which produces process plans for manufacturing the part. Human interpretation of translating CAD data into technological information required by a CAPP system is thus minimized if not eliminated.

Research and Implementation on Automatical Adjustment Method of Design Feature Model

2012 ◽  
Vol 197 ◽  
pp. 750-754
Author(s):  
Yao Chen ◽  
Guo Yuan Zhang ◽  
Jun Chao Wei ◽  
Xiu Tian Yan ◽  
Miao He
Keyword(s):  
Feature Recognition ◽  
Design Feature ◽  
Feature Modeling ◽  
Feature Model ◽  
Concurrent Design ◽  
Machining Feature ◽  
Feature Based ◽  
Feature Based Design ◽  
Product Realization

Traditional engineering design and realization typically follows a sequential pattern as described by many research publications such as French, Pahl and Beitz. These design methodologies face challenges when time is essence in product realization lifecycle. In contrast, as the design process of a product evolves，this new method incrementally creates machining feature model and realizes concurrent design feature and machining feature modeling based on an algorithm developed for local feature recognition. In addition, the method accelerated the determination of the area that require to be recognized by utilizing a dynamic link list to record the changing information of topological elements, the design features of the model generated by the feature-based design, processing and feature recognition is generated through feature model.

Algorithms to Detect Geometric Interactions in a Feature-Based Design System

1994 ◽  
Author(s):  
Rajeev Talwar ◽  
Souran Manoochehri
Keyword(s):  
Design System ◽  
Surface Information ◽  
Cad System ◽  
Knowledge Based ◽  
Feature Interactions ◽  
Different Types ◽  
Conditional Statements ◽  
Feature Based ◽  
Feature Based Design ◽  
Knowledge Based Design

Abstract This paper presents efficient and accurate algorithms for the analytical detection of geometric interactions between features in a CAD environment. The developed methodology is meant to be utilized in a knowledge-based design system using feature-based modeling. The algorithms take surface information from the CAD system and use geometric inferencing to evaluate these interactions. Features represented by both convex and concave polyhedra are considered. The methodology developed here is able to deal with concave features effectively and, therefore, eliminates the need for their decomposition into convex sub-features. Sets of conditional statements based on simple and elegant rules have been developed to distinguish different types of interactions. Feature interactions are classified as intersecting or non-intersecting. For the non-intersecting cases, the features can be contained or separate and, for both cases, they can touch each other through an edge, a vertex and/or a surface. For the intersecting cases, intersections through a surface, an edge, a common edge and a common surface are identified. For all the cases the vertices, edges and surfaces involved in the interactions are identified and the relevant distances are evaluated. A computer program has been successfully implemented for polyhedral features and examples have been given to demonstrate its effectiveness.

Handling Protrusion Features With Virtual Pockets for Automated Process Planning

1995 ◽  
Author(s):  
Yuan-Shin Lee ◽  
Dhaval Daftari
Keyword(s):  
Process Planning ◽  
Feature Model ◽  
Design System ◽  
Second Stage ◽  
Automated Process Planning ◽  
Negative Feature ◽  
Feature Based ◽  
Automated Process ◽  
Feature Based Design ◽  
Manufacturing Features

Abstract In this paper a two step approach for the transformation of design features to manufacturing features is presented. In the first stage of the proposed algorithm, a methodology for handling protrusion features by the decomposition of the surrounding volume into basic, negative, machinable volumes is discussed. In the second stage called the feature refinement stage, relevant manufacturing information is appended to the negative feature model resulting from the first stage. The proposed methodology can be used to support automated process planning. Practical examples and computer implementation in an object oriented feature based design system are also presented.

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.

An integrated form-feature-based design system for manufacturing

1995 ◽  
Vol 6 (5) ◽  
pp. 277-290 ◽  
Author(s):  
Chuan-Jun Su ◽  
Tien-Lung Sun ◽  
Chang-Nien Wu ◽  
Richard J. Mayer
Keyword(s):  
Design System ◽  
Feature Based ◽  
Feature Based Design ◽  
Form Feature

scholarly journals A Prototype of Feature-Based Design for Assembly

1990 ◽  
Author(s):  
T. L. DeFazio ◽  
A. C. Edsall ◽  
R. E. Gustavson ◽  
J. A. Hernandez ◽  
P. M. Hutchins ◽  
...  
Keyword(s):  
Information Source ◽  
Design Feature ◽  
Functional System ◽  
Design System ◽  
Prototype System ◽  
Design For Assembly ◽  
Assembly Process ◽  
Feature Based ◽  
Feature Based Design ◽  
Assembly Analysis

Abstract This paper describes a prototype software system that implements a form of feature-based design for assembly. It is not an automated design system but instead a decision and design aid for designers interested in Concurrent Design. Feature-based design captures design intent (assembly topology, product function, manufacturing, or field use) while creating part and product geometry. Design for assembly as used here extends existing ideas about critiquing part shapes and part count to include assembly process planning, assembly sequence generation, assembly fixturing assessments, and assembly process costs. This work was primarily Interested in identifying the information important to DFA tasks, and how that information could be captured using feature-based design. It was not intended to extend the state of the art in feature-based geometry creation, but rather to explore the uses of the information that can be captured. The prototype system has been programmed in LISP on Sun workstations. Its research contributions comprise integration of feature-based design with several existing and new assembly analysis and synthesis algorithms; construction of feature properties to meet the needs of those algorithms; a carefully chosen division of labor between designer and computer; and illustration of feature-based models of products as the information source for assembly analysis and process design. Some of its functions have been implemented approximately or partially but they give the flavor of the benefits to be expected from a fully functional system.

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.

Sign in / Sign up

Export Citation Format

Share Document