scholarly journals Determination of appropriate level of detail of a three-dimensional computer-aided design model from a permissible dissimilarity for fully automated simplification

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401770712 ◽  
Author(s):  
Soonjo Kwon ◽  
Hyungki Kim ◽  
Duhwan Mun ◽  
Soonhung Han
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Level Of Detail ◽  
Design Model ◽  
Prototype System ◽  
Design Models ◽  
Automated Method ◽  
Level Of Details ◽  
Computer Aided ◽  
Aided Design

The level of detail required for a three-dimensional computer-aided design model varies according to its purpose. Thus, it is necessary to develop an automated method for controlling the level of detail of three-dimensional computer-aided design models to facilitate the use of three-dimensional computer-aided design models in different application areas. When multiple three-dimensional computer-aided design models need to be simplified in a batch mode without user intervention, it would be advantageous if the appropriate level of details for the models were automatically determined. This study proposes a new and automated method to determine the appropriate level of detail of each three-dimensional computer-aided design model during the simplification phase. To achieve this goal, the concept of an “appropriate level of detail for simplification” was defined from the viewpoint of shape dissimilarity. After that, an algorithm was developed to determine the appropriate level of detail of a model by adopting the feature-based simplification method and the shape distribution–based comparison method. Finally, a prototype system was invented to verify the proposed method through experiments, in which the appropriate level of details for test cases were determined by the system.

scholarly journals Computer-aided design model parameterisation to derive knowledge useful for manufacturing design decisions

2017 ◽  
Vol 232 (4) ◽  
pp. 621-628 ◽  
Author(s):  
Trevor Robinson ◽  
Imelda Friel ◽  
Cecil G Armstrong ◽  
Adrian Murphy ◽  
Joe Butterfield ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Design Feature ◽  
Design Model ◽  
Optimal Model ◽  
Design Decisions ◽  
Design Models ◽  
Computer Aided ◽  
Novel Approaches ◽  
Aided Design ◽  
Product Assembly

This article presents a number of novel approaches for deriving intelligence from the parameterisation of computer-aided design models to assist the engineer in making manufacturing-related decisions. During the design process, a disjoint can occur between the nominally defined computer-aided design feature parameters and the dimensions which govern manufacture and influence ease of product assembly. In this work, a link between the two representations is established, which simplifies the process of using the parameters defining the features in the computer-aided design model to make manufacturing-related decisions such as the allocation of dimensional tolerances or dealing with fit issues. It also offers insights about how the model should be parameterised to provide the optimal model utility from the designer’s perspective with respect to the manufacturing domain.

Virtual concurrent product development of plastic injection moulds

2000 ◽  
Vol 214 (2) ◽  
pp. 165-168 ◽  
Author(s):  
G Britton ◽  
T S Beng ◽  
Y Wang
Keyword(s):  
Product Development ◽  
Collaborative Design ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Prototype System ◽  
Computer Aided ◽  
Cad Cam ◽  
Cad Models ◽  
Aided Design ◽  
Plastic Injection

This paper describes three approaches for virtual product development of plastic injection moulds. The first is characterized by the use of three-dimensional computer aided design (CAD) for product design, two-dimensional drafting for mould design and three-dimensional computer aided design/manufacture (CAD/CAM) for mould manufacture. The second is characterized by the use of three-dimensional CAD models by all three participants, but between any two participants some form of file conversion is normally required because different CAD systems are used. The first two approaches share one common feature: the models are passed serially from the product designer to the mould designer and on to the toolmaker. They represent current practice in industry. The third approach is a proposed collaborative design process. Participants can work concurrently on the same model, sharing their knowledge and experience. The process is currently being refined and will be validated later this year with a prototype system based on Unigraphics iMAN software.

Graph-Based Simplification of Feature-Based Three-Dimensional Computer-Aided Design Models for Preserving Connectivity

2015 ◽  
Vol 15 (3) ◽  
Author(s):  
Soonjo Kwon ◽  
Byung Chul Kim ◽  
Duhwan Mun ◽  
Soonhung Han
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Evaluation Metrics ◽  
Prototype System ◽  
Cad Model ◽  
3D Cad ◽  
Computer Aided ◽  
Cad Models ◽  
Feature Based ◽  
Aided Design

The required level of detail (LOD) of a three-dimensional computer-aided design (3D CAD) model differs according to its purpose. It is therefore important that users are able to simplify a highly complex 3D CAD model and create a low-complexity one. The simplification of a 3D CAD model requires the application of a simplification operation and evaluation metrics for the geometric elements of the 3D CAD model. The evaluation metrics are used to select those elements that should be removed. The simplification operation removes selected elements in order to simplify the 3D CAD model. In this paper, we propose the graph-based simplification of feature-based 3D CAD models using a method that preserves connectivity. First, new evaluation metrics that consider the discrimination priority among several simplification criteria are proposed. Second, a graph-based refined simplification operation that prevents the separation of a feature-based 3D CAD model into multiple volumes is proposed. Finally, we verify the proposed method by implementing a prototype system and performing simplification experiments using feature-based 3D CAD models.

scholarly journals Rail wear inspection based on computer-aided design model and point cloud data

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881678 ◽  
Author(s):  
Peng Chen ◽  
Yong Hu ◽  
Wen-Tao Li ◽  
Pei-Jun Wang
Keyword(s):  
Computer Aided Design ◽  
Point Cloud ◽  
Structured Light ◽  
Three Dimensional ◽  
Point Clouds ◽  
Design Model ◽  
Inspection System ◽  
Rail Wear ◽  
Computer Aided ◽  
Aided Design

Railway transportation demands more efficient and accurate rail wear inspection systems to ensure the train operation safety. To obtain continuous three-dimensional data, a structured light rail wear inspection system is developed in this article, and the data processing method for aligning the point cloud from structured light scanning to the nominal computer-aided design model of the rail is investigated. For further data registration, the point cloud of the computer-aided design model is generated and the normal vectors of these points are calculated. In the coarse registration, conformal geometric algebra is applied to align the segmented point clouds by intuitive geometric calculations to those from the computer-aided design model. In the fine registration, the accurate alignment of the point clouds is implemented by the iterative closest point algorithm. The vertical and lateral wear amounts are obtained on the cross section by slicing the aligned three-dimensional point clouds data. Finally, the proposed system and method are validated by comparing the vertical wear amounts with the two-dimensional laser scanning and contact measurement results.

scholarly journals Automatized Evaluation of Students’ CAD Models

2021 ◽  
Vol 11 (4) ◽  
pp. 145
Author(s):  
Nenad Bojcetic ◽  
Filip Valjak ◽  
Dragan Zezelj ◽  
Tomislav Martinec
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Computer Application ◽  
Test Cases ◽  
Cad Model ◽  
Computer Solution ◽  
3D Cad ◽  
Computer Aided ◽  
Cad Models ◽  
Aided Design

The article describes an attempt to address the automatized evaluation of student three-dimensional (3D) computer-aided design (CAD) models. The driving idea was conceptualized under the restraints of the COVID pandemic, driven by the problem of evaluating a large number of student 3D CAD models. The described computer solution can be implemented using any CAD computer application that supports customization. Test cases showed that the proposed solution was valid and could be used to evaluate many students’ 3D CAD models. The computer solution can also be used to help students to better understand how to create a 3D CAD model, thereby complying with the requirements of particular teachers.

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