scholarly journals FROM CAD TO PHYSICS-BASED DIGITAL TWIN: FRAMEWORK FOR REAL-TIME SIMULATION OF VIRTUAL PROTOTYPES

2020 ◽  
Vol 1 ◽  
pp. 335-344
Author(s):  
J. G. Pereira ◽  
A. Ellman

AbstractEngineering work is mostly done in 3D CAD software throughout the engineering process from conceptual design and layout of products. Physics-Based Virtual Prototypes are very valuable addition on Computer Aided Engineering enabling product development simulators, training simulators and digital twin concept in product lift-cycle process. In this work, we present a framework, how such virtual prototypes can be developed from 3D CAD models with meaningful effort.

2021 ◽  
Vol 11 (4) ◽  
pp. 145
Author(s):  
Nenad Bojcetic ◽  
Filip Valjak ◽  
Dragan Zezelj ◽  
Tomislav Martinec

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.


Author(s):  
Sree Shankar S. ◽  
Anoop Verma ◽  
Rahul Rai

Since its inception, computer aided 3D modeling has primarily relied on the Windows, Icons, Menus, Pointer (WIMP) user interface. WIMP has rarely been able to tap into the natural intuitiveness and imagination of the user which accompanies any design process. Brain-computer interface (BCI) is a novel modality that uses the brain signals of a user to enable natural and intuitive interaction with an external device. The BCI’s potential to become an important modality of natural interaction for 3D modeling is almost limitless and unexplored. In theory, using BCI one can create any 3D model by simply thinking about it. This paper presents a basic framework for using BCI as an interface for computer aided 3D modeling. This framework involves the task of recording and recognizing electroencephalogram (EEG) brain wave patterns and electromyogram (EMG) signals corresponding to facial movements. The recognized EEG/EMG brain signals and associated keystrokes are used to activate/control different commands of a CAD package. Eight sample CAD models are created using the Emotiv EEG head set based BCI interface and Google SketchUp and presented to demonstrate the efficacy of the developed system based on the framework. To further exhibit BCI’s usability, human factor studies have been carried out on subjects from different backgrounds. Based on preliminary results, it is concluded that EEG/EMG based BCI is suitable for computer aided 3D modeling purposes. Issues in signal acquisition, system flexibility, integration with other modalities, and data collection are also discussed.


Author(s):  
Cong Hong Phong Nguyen ◽  
Young Choi

The lightweight representation of three-dimensional computer-aided design (3D CAD) models has drawn much attention from researchers as its usefulness in collaborative product development is vast. Existing approaches are mostly based on feature depression or mesh-based simplification. In this article, a new approach for 3D CAD lightweight representation based on combining triangular mesh representation and boundary representation (B-rep) is proposed. The corresponding data structure as well as the conversion method from original data given in B-rep was developed. Considered as an essential application in collaborative product development, a case study on the visualization process of large-scale assembly models represented in the proposed lightweight representation was also conducted. The validation of the approach was performed via experiments with 3D CAD models in SAT format and by benchmarking with the conventional all-faceted approach with the same level of mesh resolution.


Author(s):  
G Britton ◽  
T S Beng ◽  
Y Wang

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.


Author(s):  
Weihang Zhu

This paper presents an infrastructure that integrates a haptic interface into a mainstream computer-aided design (CAD) system. A haptic interface, by providing force feedback in human-computer interaction, can improve the working efficiency of CAD/computer-aided manufacturing (CAM) systems in a unique way. The full potential of the haptic technology is best realized when it is integrated effectively into the product development environment and process. For large manufacturing companies this means integration into a commercial CAD system (Stewart, et al., 1997, “Direct Integration of Haptic User Interface in CAD Systems,” ASME Dyn. Syst. Control Div., 61, pp. 93–99). Mainstream CAD systems typically use constructive solid geometry (CSG) and boundary representation (B-Rep) format as their native format, while internally they automatically maintain triangulated meshes for graphics display and for numerical evaluation tasks such as surface-surface intersection. In this paper, we propose to render a point-based haptic force feedback by leveraging built-in functions of the CAD systems. The burden of collision detection and haptic rendering computation is alleviated by using bounding spheres and an OpenGL feedback buffer. The major contribution of this paper is that we developed a sound structure and methodology for haptic interaction with native CAD models inside mainstream CAD systems. We did so by analyzing CAD application models and by examining haptic rendering algorithms. The technique enables the user to directly touch and manipulate native 3D CAD models in mainstream CAD systems with force/touch feedback. It lays the foundation for future tasks such as direct CAD model modification, dynamic simulation, and virtual assembly with the aid of a haptic interface. Hence, by integrating a haptic interface directly with mainstream CAD systems, the powerful built-in functions of CAD systems can be leveraged and enhanced to realize more agile 3D CAD design and evaluation.


Author(s):  
Soonjo Kwon ◽  
Byung Chul Kim ◽  
Duhwan Mun ◽  
Soonhung Han

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.


2011 ◽  
Vol 121-126 ◽  
pp. 1844-1848
Author(s):  
Fang Yu Li ◽  
Ye Fei Li

In this study a methodology of computer aided conceptual design in product development based on ergonomics was put forward. When products concerned with people are designed, ergonomics should be taken into account. The digital human model was used to decide the layout of design scheme. Ergonomics features were extracted in workplace analysis. With the aid of software Pro/Engineer, the whole human and machine virtual environment were built. A case of the modeling and size specification of the excavator cab for different drivers was given as the example to show the whole design process. The results shows that the development of ergonomics, computer aided concept design and anthropometry can help the designers to improve product development.


Author(s):  
Reiner Anderl ◽  
Thomas Rollmann ◽  
Zhenyu Wu ◽  
Youssef Chahadi

Today’s industry faces the competing pressures of having to develop more and more innovative concepts at less cost. One possibility of supporting these rivaling tasks is leaving the idea of traditional product development and introducing an algorithm-based product development paradigm. By this approach it will be possible to quickly generate a large number of possible solutions based on the future product’s primary specifications and requirements. The result of this process is a set of discrete CAD models for each possible solution, from which the designer can select the most suitable one for his specific task. By this approach, engineers shall be able to plan and design their complete draft in an automated, computer aided way. In short, they need to specify the essential requirements and conditions for their design and subsequently will obtain a set of mathematically and functionally optimized CAD-models, from which the best fitting part geometry can be passed on for production.


2013 ◽  
Vol 15 (5) ◽  
pp. 625-635 ◽  
Author(s):  
Ansgar Waldbaur ◽  
Bernardo Carneiro ◽  
Paul Hettich ◽  
Elisabeth Wilhelm ◽  
Bastian E. Rapp
Keyword(s):  
3D Cad ◽  

Author(s):  
Atin Angrish ◽  
Akshay Bharadwaj ◽  
Binil Starly

Abstract Deep neural networks (DNNs) have been successful in classification and retrieval tasks of images and text, as well as in the graphics domain. However, these DNNs algorithms do not translate to 3D engineering models used in the product design and manufacturing. This paper studies the use of multi-view convolutional neural network (MVCNN) algorithm enhanced by the addition of engineering metadata, for classification and retrieval of 3D computer-aided design (CAD) models. The proposed algorithm (MVCNN++) builds on the MVCNN algorithm with the addition of part dimension data, improving its efficacy for manufacturing part classification and yielding an improvement in classification accuracy of 5.8% over the original version. Unlike datasets used for 3D shape classification and retrieval in the computer graphics domain, engineering level description of 3D CAD models do not yield themselves to neat, distinct classes. Techniques such as relaxed-classification and prime angled cameras for capturing feature detail were used to address training data capture issues specific to 3D CAD models, along with the use of transfer learning to reduce training time. Our study has shown that DNNs can be used to search and discover relevant 3D engineering models in large public repositories, making 3D models accessible to the community.


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