Contouring Medial Surface of Thin-Plate Structures Using Local Marching Cubes

2005 ◽  
Vol 5 (2) ◽  
pp. 111-115 ◽  
Author(s):  
Tomoyuki Fujimori ◽  
Hiromasa Suzuki ◽  
Yohei Kobayashi ◽  
Kiwamu Kase
Keyword(s):  
Thin Plate ◽  
Computer Aided Design ◽  
Prototype System ◽  
Marching Cubes ◽  
Plate Structures ◽  
Medial Surface ◽  
Surface Models ◽  
Marching Cubes Algorithm ◽  
Computer Aided ◽  
Ct Data

This paper describes a new algorithm for contouring a medial surface from CT (computed tomography) data of a thin-plate structure. Thin-plate structures are common in mechanical structures, such as car body shells. When designing thin-plate structures in CAD (computer-aided design) and CAE (computer-aided engineering) systems, their shapes are usually represented as surface models associated with their thickness values. In this research, we are aiming at extracting medial surface models of thin-plate structures from their CT data for use in CAD and CAE systems. Commonly used isosurfacing methods, such as marching cubes, are not applicable to contour the medial surface. Therefore, we first extract medial cells (cubes comprising eight neighboring voxels) from the CT data using a skeletonization method to apply the marching cubes algorithm for extracting the medial surface. It is not, however, guaranteed that the marching cubes algorithm can contour those medial cells (in short, not “marching cubeable”). In this study, therefore we developed cell operations that correct topological connectivity to guarantee such marching cubeability. We then use this method to assign virtual signs to the voxels to apply the marching cubes algorithm to generate triangular meshes of a medial surface and map the thicknesses of thin-plate structures to the triangle meshes as textures. A prototype system was developed to verify some experimental results.

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.

Research on Innovative Product Design Method and Support System for Man-Machine Cooperation

2010 ◽  
Vol 34-35 ◽  
pp. 701-706
Author(s):  
X.Y. Liu ◽  
Yang Yin ◽  
L.P. Zhou
Keyword(s):  
Product Design ◽  
Support System ◽  
Information Exchange ◽  
Computer Aided Design ◽  
Processing System ◽  
Human Information Processing ◽  
Prototype System ◽  
Innovative Product ◽  
Design Environment ◽  
Computer Aided

According to the limitations of existing innovative design methods, a research ideology was proposed, namely man-machine intelligent collaboration. Based on this ideology, the characteristics of information exchange between human information processing system and external design environment was analyzed, and the inherent mechanism of man-machine intelligent collaboration was explored. Moreover, some cognitive principles that the support system should follow were put forward. In terms of the characteristics of product design, incorporating cognitive science, information technology, and design technology, a computer-aided innovative product design process was presented. Finally, a preliminary prototype system of computer-aided design for product innovation was developed based on the theoretical researches aforementioned and some running instances of the prototype system were described.

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.

Development of a semi-automated die casting die design system

2002 ◽  
Vol 216 (12) ◽  
pp. 1575-1588 ◽  
Author(s):  
J Y H Fuh ◽  
S H Wu ◽  
K S Lee
Keyword(s):  
Computer Aided Design ◽  
Die Casting ◽  
Die Design ◽  
Design System ◽  
Prototype System ◽  
Market Demand ◽  
Cad Systems ◽  
Cad System ◽  
Die Casting Die ◽  
Computer Aided

The die casting industry has an imperative need for an automated or semi-automated approach for die casting die design. One of the key challenges that die makers face is how to shorten the lead-time to the market and reduce the cost in die design and manufacturing. Most die makers have employed computer aided design (CAD) systems to improve the efficiency and quality of die design. However, conventional CAD systems do not have the functionality specially for the die casting die design, therefore, a specific computer aided system for die casting die design is needed to meet the market demand. This paper describes a prototype system structured by several functional modules as specific add-on applications on a commercial CAD system for die casting die design. These modules include data initialization, cavity layout, gating system design, die-base, parting, standard component design, etc. Focus of the development will be placed on gating, runner and die-base design.

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.

AN ALGORITHM TO CONSTRUCT THE CAD MODEL OF A RESIDUAL LIMB

2001 ◽  
Vol 13 (03) ◽  
pp. 149-158 ◽  
Author(s):  
LAI-HSING HSU ◽  
FU-MEI HSU ◽  
YOU-LI CHOU ◽  
JU-YI HSU ◽  
HANG LEONG ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Numerical Control ◽  
Prototype System ◽  
Cad Model ◽  
Residual Limb ◽  
Cnc Machine ◽  
B Spline ◽  
Spline Curve ◽  
Computer Aided ◽  
Aided Design

A duplicated mold of the residual limb of an amputee is usually needed to make the socket of prosthesis for the patient. However, traditional means to duplicate a positive mold is time-consuming, patient suffering and intensive manual-efforts required. The study has developed a prototype system that allows a prosthetist to construct the computer-aided design(CAD) model of residual limb easily using it's digitized points based on the concept of reverse engineering. First of all, the topographic data of a residual limb is captured using a non-intrusive scanning machine. The scanned data is then used as the input of a self-developed system that is based on the theories of B-spline curve and lofted surface to process the digitized points. The CAD model can then be built and transferred to a computer-aided manufacturing(CAM) system to generate the code for a computer numerical control(CNC) machine to make the duplicated mold of the residual limb.

GUIDING TEMPLATES FOR PEDICLE SCREWS INSERTION: A PRELIMINARY STUDY

2012 ◽  
Vol 24 (06) ◽  
pp. 495-501 ◽  
Author(s):  
Jing-Jing Fang ◽  
Tai-Hong Kuo ◽  
Ruey-Mo Lin ◽  
Cheng-Yu Ho
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Pedicle Screws ◽  
Ct Scanning ◽  
Design Environment ◽  
Average Deviation ◽  
Screw Insertion ◽  
Entry Points ◽  
Computer Aided ◽  
Ct Data

Fixation of pedicle screws necessitates high surgical skill and a great deal of experience in order to avoid injuries to nerves and vessels. In this study, we develop a computer-aided procedure to produce personalized drill guides that are designed to enhance the safety of pedicle screw insertion in the spinal region. Based on a patient's computed tomography (CT) data, it is possible to design personalized drill guides in a self-developed computer-aided design environment. These guides are designed to fit on the surface of vertebrae in a unique position in order to indicate both the preplanned drill path and the drilling length into the pedicle. A rapid prototyping device is used as a three-dimensional printer to produce the shape of reference areas on bone surfaces. Postoperative CT scans are obtained, and the accuracy of the pedicle screws is measured. By using customized templates in a case study, the guiding templates are shown to be highly accurate and to provide great assistance for planning and executing surgeries. The accuracy of screw placement is confirmed with postoperative CT scanning. The average angle of the drilling paths between planning and postsurgery is approximately 1.05°. The average deviation of entry points of drilling paths between planning and postsurgery is approximately 2.99 mm. The performance proves a high degree of accuracy in comparison with conventional techniques achieved through fluoroscopy. However, a significant number of clinical cases is needed to validate the feasibility of this method. The device is proven to be reliable and compatible; in the future, surgeons can use the guiding templates to complete more complicated cases such as those involving idiopathic scoliosis and cervical complications.

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