Interactive Freeform Clay Modeling Supported by 3D Scanning and Robot Machining

Author(s):  
Y. Song ◽  
J. S. M. Vergeest ◽  
T. Wiegers

Effective and efficient prototyping is always a challenging topic in design and prototyping. For this purpose, an interactive prototyping center is developed in this paper. The proposed technique is based on a synthesis of clay modeling, 3-Dimensional (3-D) scanning, robot machining and advanced geometric tools. Using 3-D scanning and reverse engineering techniques, a physical clay model is digitized to a Computer Aided Design (CAD) model by mesh representation. By advanced geometric tools, the mesh model can be changed easily following the user’s ideas. Those changes can be reflected to the clay model by robot machining. Furthermore, manual modifications on the existing clay model also can be added to the CAD model by 3-D scanning. For robot machining, a method based on 3-D scanning is used to calibrate the workpiece coordinate and the fixtures. Based on this system, virtual prototyping and physical prototyping can be achieved simultaneously. Solid or surface CAD models can be constructed directly from the mesh model after the prototyping stage. Experiments were made to demonstrate the effectiveness of the prototyping system. The possible applications in industrial product design are described as well.

Author(s):  
Y. Song ◽  
J. S. M. Vergeest ◽  
T. R. Langerak

Prototyping plays an important role in industrial product designs. In this paper, for achieving a more intuitive and interactive prototyping, a selective clay milling center is introduced based on a synthesis of clay modeling, 3-Dimensional (3-D) scanning, robot machining and advanced geometric tools. In the system, the product shape design may start either from a physical hand-made clay model or a virtual Computer-Aided Design (CAD) model. Via 3-D scanning techniques, manual modifications of the clay model can be captured in the CAD form and in the meantime, geometric modifications of the CAD model can be fed back to the physical model by an efficient robot machining method, named selective clay milling. This design cycle is repeated until a satisfied prototype iterates. For a better control of the interactions between the manual modeling and robot milling, a 3-D scanning based calibration system has been developed in order to arbitrarily position the workpiece in the design process. With several experiments, the effectiveness of the proposed system is shown and the possible applications of the proposed system in industrial product design are described as well.


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.


2009 ◽  
Vol 131 (12) ◽  
Author(s):  
Min Li ◽  
Y. F. Zhang ◽  
J. Y. H. Fuh ◽  
Z. M. Qiu

In product design, a large proportion of three-dimensional (3D) computer-aided design (CAD) models can be reused to facilitate future product development due to their similarities in function and shape. This paper presents a novel method that incorporates modeling knowledge into CAD model similarity assessment to improve the effectiveness of reuse-oriented retrieval. First, knowledge extraction is performed on archived feature-based CAD models to construct feature dependency directed acyclic graph (FDAG). Second, based on the FDAG subgraph decomposition, two useful component partitioning approaches are developed to extract simplified essential shapes and meaningful subparts from CAD models. Third, the extracted shapes and their FDAG subgraphs are indexed. Finally, the indexed shapes that are similar to user-sketched queries are retrieved to reuse, and FDAG information of the retrieved shapes is provided as redesign suggestions. Experimental results suggest that the incorporation of modeling knowledge greatly facilitates CAD model retrieval and reuse. Algorithm evaluations also show the presented method outperforms other 3D retrieval methods.


2012 ◽  
Vol 479-481 ◽  
pp. 245-249
Author(s):  
Xun Liu ◽  
Yin Zhang ◽  
Nan Liu ◽  
Zhi Yang Chen

Currently there has been much interested in developing the watermarking for 3D graphic data of NURBS or mesh model, for its function of copyright protecting, private detection under the network environment. Since the majority of computer aided design (CAD) applications employ parametric curves and surfaces, this paper proposes a watermarking mechanism for CAD models, those employ non-uniform rational B-spine (NURBS) curves and surfaces as their main shape-defining primitives. This algorithm using relative knot insertion method embeds the watermarks generated by features sequence identification into the NURBS primitives. The shapes are exactly preserved. We don’t need ether original model or original message to extract the watermarks from the watermarked models, since it is blind. By experimental result, we confirmed the watermarking mechanism is robust against most common attacks.


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.


2020 ◽  
pp. 1-3
Author(s):  
Abhishek Bansal ◽  
Navneet kukreja ◽  
Shivangi Trivedi ◽  
Jayant Verma ◽  
Jyoti Bansal ◽  
...  

Abstract: The process of 3 Dimensional (3D) printing is used to create a 3D object with the help of a computer aided design (CAD) model, by successive addition of material layer by layer thus it is also known as additive manufacturing. During 1990’s, the technique of 3D printing was only applied for the manufacture of aesthetic or functional prototypes and was suitably named as rapid prototyping. The following descriptive review presents with an overview about contemporary 3D printing technologies and their use in various specialties of dentistry and largely focusing on the applications of this technology in the endodontics.


Author(s):  
P A Prieto ◽  
D K Wright ◽  
S F Qin

The paper describes a novel method for updating computer aided design (CAD) models with information taken from physical models in the early stages of design. The new approach is an image mapping based method in which an initial. CAD model is transferred to a soft rapid prototype model (RPM) made by a three-dimensional printer and sculpted in order to carry out formal developments. The RPM has a built-in contrasting three-dimensional grid composed of parallel orthogonal planes, and the initial CAD model is represented by cross-section curves corresponding to the RPM grid. The initial CAD geometry is then updated from images of the developed RPM by matching the differences between the initial CAD model and the modified RPM, making use of identical perspective transformations and viewpoints for the initial CAD model and an RPM image. Examples studied varied from a small depression on a cube face to general freeform surfaces. Compared with typical reverse engineering (RE) processes, the present approach is simpler and more direct. It is not necessary to use three-dimensional scanning or coordinate measuring devices for updating existing initial geometrical CAD models with data obtained from physical models.


Author(s):  
A. Alizadeh Naeini ◽  
A. Ahmad ◽  
M. M. Sheikholeslami ◽  
P. Claudio ◽  
G. Sohn

Abstract. Thanks to the proliferation of commodity 3D devices such as HoloLens, one can have easy access to the 3D model of indoor building objects. However, this model does not match 2D available computer-aided design (CAD) models as the as-built model. To address this problem, in this study, a 3-step registration method is proposed. First, binary images, including walls and background, are generated for the 3D point cloud (PC) and the 2D CAD model. Then, 2D-to-2D corresponding pixels (CPs) are extracted based on the intersection of walls in each binary image of PC (BIPC) and binary CAD (BCAD) model. Since the 3D PC space coordinates (XYZ) of all BIPC's pixels are known, BIPC part of the 2D-to-2D CPs can be considered 3D. Lastly, the parameters of the 8-parameter affine are estimated using the 2D-to-3D CPs, which are pixel coordinates in BCAD model as well as their correspondences in the 3D PC space. Experimental results indicate the efficiency of our proposed method compared to manual registration.


Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2326
Author(s):  
Nikola Korunovic ◽  
Dragan Marinkovic ◽  
Miroslav Trajanovic ◽  
Manfred Zehn ◽  
Milorad Mitkovic ◽  
...  

Structural analysis, based on the finite element method, and structural optimization, can help surgery planning or decrease the probability of fixator failure during bone healing. Structural optimization implies the creation of many finite element model instances, usually built using a computer-aided design (CAD) model of the bone-fixator assembly. The three most important features of such CAD models are: parameterization, robustness and bidirectional associativity with finite elements (FE) models. Their significance increases with the increase in the complexity of the modeled fixator. The aim of this study was to define an automated procedure for the configuration and placement of fixators used in the treatment of long bone fractures. Automated and robust positioning of the selfdynamisable internal fixator on the femur was achieved and sensitivity analysis of fixator stress on the change of major design parameters was performed. The application of the proposed methodology is considered to be beneficial in the preparation of CAD models for automated structural optimization procedures used in long bone fixation.


Author(s):  
Xiantao Cai ◽  
Weidong Li ◽  
Fazhi He

Model security for collaborative product design in a networked environment (or called networked manufacture, grid manufacture, and cloud manufacture) is an important but also challenging research issue. In order to support collaborative product design in a secure and flexible means, a partial encryption based secure sharing method for Computer Aided Design (CAD) model is presented in this paper. Based on the above method, parts of a CAD model can be selected flexibly by users for encrypting according to different users’ requirements. The secret keys for the different parts of the CAD model can be customized to meet the requirements of users. Case studies have been developed to demonstrate the effectiveness of the proposed method.


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