A CAD System for Designers’ Decision Making: An Approach With 2D and 3D Integrated and Hierarchical Assembly Models

1991 ◽  
Author(s):  
S. Minami ◽  
T. Ishida ◽  
S. Yamamoto ◽  
K. Tomita ◽  
M. Odamura
Keyword(s):  
Decision Making ◽  
Computer Aided Design ◽  
Mechanical Design ◽  
Prototype System ◽  
Dimensional Model ◽  
3 Dimensional ◽  
Hierarchical Assembly ◽  
Cad System ◽  
Aided Design ◽  
2D And 3D

Abstract A concept for the initial stage of the mechanical design and its implementation in the computer-aided design (CAD) are presented. The process of decision making in design is: (1) determining an outline of the whole assembly using a 2-dimensional model that is easy to operate; (2) checking the outline using a 3-dimensional model in which it is easy to identify the spatial relationships; (3) determining details of its sub-assemblies or their components using the 2-dimensional model; and (4) checking the details using the 3-dimensional model. The CAD system must provide consistent relationships through all the steps. For that, following functions are implemented in our prototype system: (1) a 2D and 3D integrated model for consistency between 2- and 3-dimensional shapes, (2) a hierarchical assembly model with dimensional constraints for consistency within an assembly and their components, and (3) a check on constraints for consistency between shapes and designers’ intentions. As a result, the system can provide an environment well fitted to the designers’ decision making process.

scholarly journals Prototype system for supporting the incremental modelling of vague geometric configurations

1997 ◽  
Vol 11 (4) ◽  
pp. 287-310 ◽  
Author(s):  
X. Guan ◽  
A.H.B. Duffy ◽  
K.J. MacCallum
Keyword(s):  
Computer Aided Design ◽  
Geometric Design ◽  
Geometric Configuration ◽  
Prototype System ◽  
Cad System ◽  
Detail Design ◽  
Iterative Development ◽  
Geometric Concepts ◽  
High Level ◽  
Aided Design

AbstractFew existing Computer Aided Design (CAD) systems provide assistance to designers in developing geometric concepts at the early design stages. Instead they require a high level of precision and detail suited to detail design. To support the early geometric design, a CAD system should provide utilities for the rapid capture and iterative development of vague geometric models. This paper presents a pilot system that is being developed based on such a vision. The system has adopted minimum commitment modelling and incremental refinement as the guiding principles. The representation of geometric configuration is based on a parametric and constraint-based geometric design model, and provides a uniform representation of the approximate and precise size and location parameters. A constraint-based mechanism has been developed for processing geometric information. The use of the system in assisting the development of a geometric configuration is also demonstrated. Finally, features and limitations of the system as well as relations to relevant works are discussed, and based on this a number of key research directions are established.

scholarly journals Strategy for the engineering integration of the ESS accelerator

2016 ◽  
Vol 44 ◽  
pp. 1660208
Author(s):  
Nikolaos Gazis ◽  
David McGinnis ◽  
Stephen Molloy ◽  
Eugene Tanke ◽  
Carl-Johan Hardh ◽  
...  
Keyword(s):  
Information Exchange ◽  
Computer Aided Design ◽  
Mechanical Design ◽  
Technical Information ◽  
Technical Requirements ◽  
Key Issues ◽  
Spallation Source ◽  
Engineering Integration ◽  
Under Construction ◽  
Aided Design

The European Spallation Source (ESS), currently under construction in Lund, Sweden, will be the world’s most powerful source of neutrons. The goal is to deliver neutrons to users in 2019 and reach full power sometime in the middle of the following decade. One of the key issues for ESS is to develop a strategy, along with the proper innovative tools, to efficiently communicate and smoothly collaborate between divisions and groups inside ESS and with its outside collaborators, so-called In-Kind Contributors (IKC). Technical requirements related to the scope to be delivered are among the most important technical information to be exchanged. This information exchange is facilitated by using a commercial requirements management database that is accessible through the web. The physics multidisciplinary needs are linked with the engineering integration through LinacLego, which is a tool that provides all updated lattice data for the accelerator. The lattice information is then gathered and utilized to control the physical positioning of the mechanical engineering components for the accelerator. The precision for this operation is provided by a dedicated mechanical design skeleton in a Computer Aided Design (CAD) environment. Finally, the realization of all these steps is supervised in detail and continuously evaluated. In this way the required ESS machine design can be delivered, both in terms of the engineering and the physics aspects.

scholarly journals Are Two Heads Better Than One For Computer-Aided Design?

2021 ◽  
pp. 1-38
Author(s):  
Vrushank Phadnis ◽  
Hamza Arshad ◽  
David Wallace ◽  
Alison Olechowski
Keyword(s):  
Computer Aided Design ◽  
Mechanical Design ◽  
Major Effect ◽  
Pair Programming ◽  
Digital Modeling ◽  
Computer Aided ◽  
Model Instance ◽  
Parallel Mode ◽  
Aided Design ◽  
Pair Work

Abstract With the availability of cloud-based software, ubiquitous internet and advanced digital modeling capabilities, a new potential has emerged to design physical products with methods previously embraced by the software engineering community. One such example is pair programming, where two coders work together synchronously to develop one piece of code. Pair programming has been shown to lead to higher quality code and designer satisfaction. Cutting-edge collaborative Computer-aided Design (CAD) technology affords the possibility to apply synchronous collaborative access in mechanical design. We test the generalizability of findings from the pair programming literature to the same dyadic configuration of work in CAD, which we call pair CAD. We performed human subject experiments with 60 participants to test three working styles: individuals working by themselves, pairs sharing control of one model instance and input, and pairs able to edit the same model simultaneously from two inputs. We compare the working styles on speed and quality, and propose mechanisms for our observations via interpretation of patterns of communication, satisfaction, and user cursor activity. We find that on a per-person basis, individuals were faster than pairs due to coordination and overhead inefficiencies. We find that pair work, when done with a single shared input, but not in a parallel mode, leads to higher quality models. We conclude that it is not Industry 4.0 technologies alone that influence designer output; choices regarding work process have a major effect on design outcomes, and we can tailor our process to suit project requirements.

Computer Aided Design of a Pattern and Risers for Casting Processes: Part 1

1991 ◽  
Vol 113 (1) ◽  
pp. 59-66
Author(s):  
Jong Cheon Park ◽  
Kunwoo Lee
Keyword(s):  
Computer Aided Design ◽  
Unique Feature ◽  
Three Dimensional ◽  
Automatic Design ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
High Quality ◽  
Commercial Practice ◽  
Interactive Computer Program ◽  
Aided Design

An interactive computer program has been developed to design a pattern and risers for the production of castings of high quality. In our system, the user models the shape of a final product by using the system’s modeling capability, a pattern is generated in a three-dimensional model by eliminating the holes and adding shrinkage allowances and drafts, the proper riser is created automatically, and they are united together to yield a three-dimensional model of this portion of a mold assembly. The mold can be completed after the runners and the gating systems are designed, modeled, and united which will be described in Part 2 of this work. The unique feature of this work is a realization of an automatic design of the pattern and risers by integrating the modeling capabilities and the design equations used in commercial practice.

A Framework for Designing Component Shapes in a Virtual Reality Environment

1997 ◽  
Author(s):  
Tushar H. Dani ◽  
Rajit Gadh
Keyword(s):  
Virtual Reality ◽  
Virtual Environment ◽  
User Interfaces ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Human Interaction ◽  
Prototype System ◽  
Virtual Design ◽  
Cad System ◽  
Interactive Editing

Abstract Despite advances in Computer-Aided Design (CAD) and the evolution of the graphical user interfaces, rapid creation, editing and visualization of three-dimensional (3D) shapes remains a tedious task. Though the availability of Virtual Reality (VR)-based systems allows enhanced three-dimensional interaction and visualization, the use of VR for ab initio shape design, as opposed to ‘importing’ models from existing CAD systems, is a relatively new area of research. Of interest are computer-human interaction issues and the design and geometric tools for shape modeling in a Virtual Environment (VE). The focus of this paper is on the latter i.e. in defining the geometric tools required for a VR-CAD system and in describing a framework that meets those requirements. This framework, the Virtual Design Software Framework (VDSF) consists of the interaction and design tools, and an underlying geometric engine that provides the representation and algorithms required by these tools. The geometric engine called the Virtual Modeler uses a graph-based representation (Shape-Graph) for modeling the shapes created by the user. The Shape-Graph facilitates interactive editing by localizing the effect of editing operations and in addition provides constraint-based design and editing mechanisms that are useful in a 3D interactive virtual environment. The paper concludes with a description of the prototype system, called the Virtual Design Studio (VDS), that is currently being implemented.1.

Iterative Part Design With a Virtual Reality Interface

1996 ◽  
Author(s):  
S. N. Trika ◽  
P. Banerjee ◽  
R. L. Kashyap
Keyword(s):  
Virtual Reality ◽  
Computer Aided Design ◽  
Three Dimensions ◽  
Mechanical Parts ◽  
Cad System ◽  
Current State ◽  
Feature Based ◽  
New Feature ◽  
Feature Based Design ◽  
Aided Design

Abstract A virtual reality (VR) interface to a feature-based computer-aided design (CAD) system promises to provide a simple interface to a designer of mechanical parts, because it allows intuitive specification of design features such as holes, slots, and protrusions in three-dimensions. Given the current state of a part design, the designer is free to navigate around the part and in part cavities to specify the next feature. This method of feature specification also provides directives to the process-planner regarding the order in which the features may be manufactured. In iterative feature-based design, the existing part cavities represent constraints as to where the designer is allowed to navigate and place the new feature. The CAD system must be able to recognize the part cavities and enforce these constraints. Furthermore, the CAD system must be able to update its knowledge of part cavities when the new feature is added. In this paper, (i) we show how the CAD system can enforce the aforementioned constraints by exploiting the knowledge of part cavities and their adjacencies, and (ii) present efficient methods for updates of the set of part cavities when the designer adds a new feature.

Vision-force guided precise robotic assembly for 2.5D components in a semistructured environment

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Boyoung Kim ◽  
Minyong Choi ◽  
Seung-Woo Son ◽  
Deokwon Yun ◽  
Sukjune Yoon
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Printed Circuit Board ◽  
Force Sensor ◽  
Circuit Board ◽  
Robotic Assembly ◽  
Ccd Cameras ◽  
Content Type ◽  
3 Dimensional ◽  
Aided Design

Purpose Many manufacturing sites require precision assembly. Particularly, similar to cell phones, assembly at the sub-mm scale is not easy, even for humans. In addition, the system should assemble each part with adequate force and avoid breaking the circuits with excessive force. The purpose of this study is to assemble high precision components with relatively reasonable vision devices compared to previous studies. Design/methodology/approach This paper presents a vision-force guided precise assembly system using a force sensor and two charge coupled device (CCD) cameras without an expensive 3-dimensional (3D) sensor or computer-aided design model. The system accurately estimates 6 degrees-of-freedom (DOF) poses from a 2D image in real time and assembles parts with the proper force. Findings In this experiment, three connectors are assembled on a printed circuit board. This system obtains high accuracy under 1 mm and 1 degree error, which shows that this system is effective. Originality/value This is a new method for sub-mm assembly using only two CCD cameras and one force sensor.

Systematic Derivation of a Standard Set of Declarative Constraints for Shape Definition in CAD

1999 ◽  
Author(s):  
Bernie Bettig ◽  
Jami Shah
Keyword(s):  
Computer Aided Design ◽  
Data Exchange ◽  
Mechanical Design ◽  
Constraint Solving ◽  
Mathematical Basis ◽  
Parametric Data ◽  
Geometrical Constraints ◽  
Standard Set ◽  
Aided Design ◽  
Systematic Derivation

Abstract This paper describes the derivation of a consistent and comprehensive set of geometrical constraints for shape definition in Computer-Aided Design. These are needed to enable compatibility in parametric data exchange and to promote both standard capabilities and predictable solutions from constraint solving software kernels. The paper look at the mathematical basis for constraints present in the literature and elaborates about all types of constraints that can be described by the same mathematical basis. The approach considers all combinations of distance and angle constraints, on one point or all points of curves and surfaces, as well as transformations and mappings that are required in mechanical design.

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.

Simultaneous Computer-Aided Design of Rotational Plastic Parts

1993 ◽  
Author(s):  
Colin Chong ◽  
Kiyoshi Sogabe ◽  
Kosuke Ishii
Keyword(s):  
Injection Molding ◽  
Dynamic Characteristics ◽  
Computer Aided Design ◽  
Critical Speed ◽  
Dynamic Balance ◽  
Cad System ◽  
Compatibility Analysis ◽  
Computer Aided ◽  
Plastic Parts ◽  
Aided Design

Abstract This paper addresses the problem of balancing rotational plastic parts during the early stages of design. The study develops an interactive methodology that uses a solid modeling CAD system and considers injection molding concerns simultaneously with static and dynamic balance. The Transfer Matrix Method evaluates the dynamic characteristics by predicting the approximate critical speed of the part. Design Compatibility Analysis (DCA) checks for injection molding guidelines. Using these evaluation modules interactively, designers can develop a functional and manufacturable part quickly.

Sign in / Sign up

Export Citation Format

Share Document