Process and Tolerance Considerations in the Automated Design of Fixtures

1994 ◽  
Vol 116 (2) ◽  
pp. 480-486 ◽  
Author(s):  
D. A. King ◽  
A. de Sam Lazaro
Keyword(s):  
Data Structures ◽  
Lead Time ◽  
Design System ◽  
Fixture Design ◽  
Complex Data ◽  
Cad System ◽  
Knowledge Based ◽  
Modern Manufacturing ◽  
Interactive Session ◽  
Knowledge Based Design

The long lead time for jig and fixture design is a serious bottleneck in modern manufacturing. Efforts to automate the design process using intelligent CAD systems have not been taken beyond the prototype stage mainly because of several impediments. These include the requirement of complex data structures to represent the workpiece and its attributes. Two deficiencies in existing systems for fixture design are addressed. These are (a) design for a sequence of operations and (b) design with tolerance considerations. Tolerance and process specifications are obtained from the user during an interactive session. A knowledge-based design system, REFIX, then designs a fixture for the workpiece. The fixture is optimized for a particular datum specification and sequence of operations. It is then analyzed and presented via the CAD system. REFIX is automated to minimize user-induced errors.

A Feature Extraction Interface for CAD Part Models

1991 ◽  
Author(s):  
David R. Nitschke ◽  
Yuh-Min Chen ◽  
R. Allen Miller
Keyword(s):  
Design System ◽  
Relative Positioning ◽  
Neutral Form ◽  
Cad System ◽  
Knowledge Based ◽  
Functional Specification ◽  
Design And Manufacturing ◽  
Feature Based ◽  
The Individual ◽  
Knowledge Based Design

Abstract The concept of “Features” has been recognized as a neutral form of communication between design and manufacturing. Since virtually all CAD systems define part models using B-Rep or CSG formats, a facility is needed to convert geometry based part models to ones which are feature based. This paper outlines the framework of a facility which would enable part models from any type of CAD system to be converted to a format which could be analyzed using a knowledge based design system. This facility relies on the user to recognize and isolate the individual features of the model and then extracts the dimensions, locations and relative positioning of the features within the model. These features are then organized into a feature graph for the construction of a feature based part representation. The procedures for the construction of this part representation include feature instantiation, feature placement and functional specification.

An approach to automating modular fixture design and assembly

1997 ◽  
Vol 211 (7) ◽  
pp. 509-521 ◽  
Author(s):  
J R Dai ◽  
A Y C Nee ◽  
J Y H Fuh ◽  
A Senthil Kumar
Keyword(s):  
The Other ◽  
Design System ◽  
Fixture Design ◽  
Planning Stage ◽  
Modular Fixture ◽  
Cad System ◽  
Knowledge Based ◽  
Fixture Element ◽  
Fixture Configuration ◽  
Interference Checking

In the development of a modular fixture design system, it is essential to have a modular fixture element database that can be integrated with a CAD system, in addition to the other considerations such as fixture configuration, interference checking, etc., which are also important to fixture designers. This paper describes a new method to create the fixture element database and model the fixturing towers (i.e. subassemblies). By using this method, the database can be effectively created and is easy for use in fixture assembly. The modular fixture tower database is used to represent the subassembly of fixtures. This will simplify the fixture design and assembly process. A built-in interference checking methodology is embedded in the planning stage that will ensure a collision-free fixture design. The system is developed using the knowledge- based system, ICAD, and interfacing with UG-II for modelling the workpiece. Examples of fixture design generated by the system are also provided to illustrate the development.

Linking a CAD System to an Expert System: A Step Towards a Knowledge-Based Design System for Mechanisms

1994 ◽  
Author(s):  
Wolfram Funk ◽  
Rudolf Kinzinger
Keyword(s):  
Expert System ◽  
Design Process ◽  
Computer Support ◽  
Design System ◽  
Knowledge Based Systems ◽  
Cad System ◽  
Knowledge Based ◽  
System A ◽  
Knowledge Based Design ◽  
Conventional Computer

Abstract The design process can be divided into different phases. The best order in which the designer should execute these steps remains difficult to predict. In principle, conventional computer programs can only be applied to problems for which algorithms are available. Therefore, in many fields the design process did not allow computer support. The technology of knowledge-based systems has led to new perspectives. However, knowledge-based systems can only be utilized if the well-established design aid, CAD system, is integrated into the concept of knowledge-based computer support. Conceptual considerations and new approaches to linking a CAD system to an expert system, which assists the designer in solving kinematic problems, especially in the conceptual phase, are presented.

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.

DEVELOPMENT OF A KNOWLEDGE-BASED INTELLIGENT CAD SYSTEM FOR AUTOMOTIVE PANEL DIE

2008 ◽  
Vol 07 (01) ◽  
pp. 51-54 ◽  
Author(s):  
HUI-XIA LIU ◽  
WEI WEI ◽  
XIAO WANG ◽  
LAN CAI
Keyword(s):  
Die Design ◽  
Design System ◽  
Working Process ◽  
Cad System ◽  
Knowledge Based ◽  
Working Principle ◽  
Panel Die ◽  
Automotive Panels ◽  
Automotive Panel

A knowledge-based intelligent die design system for automotive panels is developed by UG software platform. This system can accomplish design intelligently and automatically through engineering rules in the knowledge base. The framework and implementation of the system are discussed. Finally, a case study of the panel die design of car trunk in the system is implemented, which illustrates working process, working principle, implement method and practicability of the system, and validates the advanced design conception proposed in this paper.

Design and Implementation of an Intelligent CAD System

1987 ◽  
Author(s):  
M. J. Jakiela ◽  
P. Y. Papalambros
Keyword(s):  
Computer Aided Design ◽  
Design System ◽  
Knowledge Based Systems ◽  
Production Rules ◽  
Automated Assembly ◽  
Cad System ◽  
Design And Implementation ◽  
Knowledge Based ◽  
System Requirements ◽  
Aided Design

Abstract System requirements and system design for integrating a production rule program and a computer aided design system are presented. An implementation using a commercially available graphics modeling system is described. A “suggestive mode” interface is programmed as an example with application to design for automated assembly. Initial use of the implementation indicates that encoding production rules is more difficult than with conventional text-only knowledge-based systems, but that this system is a more effective way to use artificial intelligence techniques in design.

Design System Mfk—An Important Step towards an Engineering Workbench

1993 ◽  
Vol 207 (2) ◽  
pp. 105-116 ◽  
Author(s):  
H Meerkamm
Keyword(s):  
Computer Aided Design ◽  
Tolerance Analysis ◽  
Design System ◽  
Product Model ◽  
Cad System ◽  
Knowledge Based ◽  
Different Types ◽  
Analysis Design ◽  
Aided Design ◽  
Production Tolerance

The Design System mfk will support the designer by an object-orientated synthesis of parts and an integrated knowledge-based analysis. An own-product model which is completely independent from the data structure of the used computer aided design (CAD) system contains all necessary information on geometry, technology, function and organization. It allows different types of analysis: design for production, tolerance analysis, cost and stress calculation, repeated component search, etc. Usable for products of higher complexity the Design System can be seen as an approach to an engineering workbench.

KADS2: A Next Generation Knowledge Aided Design System

1997 ◽  
Author(s):  
William M. McVea ◽  
Kamyar Haghighi
Keyword(s):  
Design Methodology ◽  
System Development ◽  
Design System ◽  
Component Level ◽  
Design Synthesis ◽  
Work Related ◽  
Knowledge Based ◽  
Aided Design ◽  
Use Of Knowledge ◽  
Knowledge Based Design

Abstract Research has been conducted in the areas of design methodology, automation and use of knowledge based systems as a tool to improve the design efficiency, accuracy and consistency for mechanical power transmissions. The research capitalized on previous work related to component level design synthesis and analysis. The next logical step in the research progression was to look into system development and integration of design synthesis and analysis tools. Deliverables from this research include new knowledge acquisition techniques, a more complete model of design information flow and development and a knowledge based design assistant system, capable of integrating multiple discrete and disparate design tools.

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