Computer-aided design(CAD)software continues to be a crucial tool in digital twin application and manufacturing,facilitating the design of various products.We present a novel CAD generation method,an agent that constr...Computer-aided design(CAD)software continues to be a crucial tool in digital twin application and manufacturing,facilitating the design of various products.We present a novel CAD generation method,an agent that constructs the CAD sequences containing the sketch-and-extrude modelling operations efficiently and with high quality.Starting from the sketch and extrusion operation sequences,we utilise the transformer encoder to encode them into different disentangled codebooks to represent their distribution properties while considering their correlations.Then,a combination of auto-regressive and non-autoregressive samplers is trained to sample the code for CAD sequence con-struction.Extensive experiments demonstrate that our model generates diverse and high-quality CAD models.We also show some cases of real digital twin applications and indicate that our generated model can be used as the data source for the digital twin platform,exhibiting designers'potential.展开更多
With the progress of computer technology, CAD technique is urgent needed. In this paper, we conduct numerical and theoretical analysis and research on computer aided design technique and novel pattern for electronic a...With the progress of computer technology, CAD technique is urgent needed. In this paper, we conduct numerical and theoretical analysis and research on computer aided design technique and novel pattern for electronic architectural drawing and perspective. AUTOCAD drawing soRware because of its versatility and easy entry, in engineering has broad user base, but also because of the basis of general drawing software, often cannot directly use of the existing order efficiently complete professional drawing. We modify the current pattern and introduce our proposed pattern for advancement. The experiment proves the effectiveness of the pattern. In addition, we will conduct more insightful research in the future to nolish the current anoroach.展开更多
Purpose: Surgical templates produced by digital simulation and CAD/CAM allow for three-dimensional control of implant placement. However, due to clinical limitations, there are complications during the use of the temp...Purpose: Surgical templates produced by digital simulation and CAD/CAM allow for three-dimensional control of implant placement. However, due to clinical limitations, there are complications during the use of the template. The purpose of this study was to summarize the complications associated with the use of surgical templates for static computer-aided implant surgery. Methods: Complications were collected during the observation period, and then their implant sites were reanalyzed with simulation software. Results: There were 104 cases during the observation period, 5 cases had complications. Mechanical complications were observed in four cases, including three cases in which the frame of the template fractured during implant placement surgery and one case in which the sleeve fell off the surgical template. In one case, there was an error in the planned position. All cases were mandibular molar cases, and all cases of frame fracture were at the free end defect site. All cases had a Hounsfield unit of more than 700 at the implant site, and some of them had a significantly small jaw opening. Conclusion: Although the spread of CAD/CAM surgical templates has made it possible to avoid problems caused by the position of the implant, it has been difficult to avoid fractures in cases of mandibular free end defects with high Hounsfield unit.展开更多
Aiming to increase the efficiency of gem design and manufacturing, a new method in computer-aided-design (CAD) of convex faceted gem cuts (CFGC) based on Half-edge data structure (HDS), including the algorithms for th...Aiming to increase the efficiency of gem design and manufacturing, a new method in computer-aided-design (CAD) of convex faceted gem cuts (CFGC) based on Half-edge data structure (HDS), including the algorithms for the implementation is presented in this work. By using object-oriented methods, geometrical elements of CFGC are classified and responding geometrical feature classes are established. Each class is implemented and embedded based on the gem process. Matrix arithmetic and analytical geometry are used to derive the affine transformation and the cutting algorithm. Based on the demand for a diversity of gem cuts, CAD functions both for free-style faceted cuts and parametric designs of typical cuts and visualization and human-computer interactions of the CAD system including two-dimensional and three-dimensional interactions have been realized which enhances the flexibility and universality of the CAD system. Furthermore, data in this CAD system can also be used directly by the gem CAM module, which will promote the gem CAD/CAM integration.展开更多
The general computer-aided design （CAD） software cannot meet the mould design requirement of the autoclave process for composites, because many parameters such as temperature and pressure should be considered in the...The general computer-aided design （CAD） software cannot meet the mould design requirement of the autoclave process for composites, because many parameters such as temperature and pressure should be considered in the mould design process, in addition to the material and geometry of the part. A framed-mould computer-aided design system （FMCAD） used in the autoclave moulding process is proposed in this paper. A function model of the software is presented, in which influence factors such as part structure, mould structure, and process parameters are considered; a design model of the software is established using object oriented （O-O） technology to integrate the stiffness calculation, temperature field calculation, and deformation field calculation of mould in the design, and in the design model, a hybrid model of mould based on calculation feature and form feature is presented to support those calculations. A prototype system is developed, in which a mould design process wizard is built to integrate the input information, calculation, analysis, data storage, display, and design results of mould design. Finally, three design examples are used to verify the prototype.展开更多
Custom-made esthetic finger prostheses, which are used for rehabilitation of patients with missing or impaired fingers, have been fabricated manually. However, such fabrication is time-consuming and requires manual sk...Custom-made esthetic finger prostheses, which are used for rehabilitation of patients with missing or impaired fingers, have been fabricated manually. However, such fabrication is time-consuming and requires manual skill. Here we propose a computer-aided method for fabricating finger pros-theses to save time and allow fabrications that do not require considerable manual skill. In this method, the dimensions of a patient’s healthy finger on the contralateral hand are first measured using a caliper. Using these dimensions, a three-dimensional model is constructed for fabricating a prosthesis for the patient’s impaired finger. Using the 3D model, a mold is designed using 3D modeling tools and a computer-aided design system. The resulting mold is then fabricated using a 3D printer. A finger prosthesis is fabricated by pouring silicone resin into the mold. A finger prosthesis for a volunteer was experimentally fabricated according to the proposed method. To evaluate the size and shape of the finger prosthesis, the difference between the finger prosthesis and the original finger of the volunteer was analyzed. Because the average difference between them was 0.25 mm, it was concluded that the proposed method could be used to fabricate a finger prosthesis of adequate size and shape.展开更多
The field of solid modeling has created numerous techniques for unambiguous computer representations of three-dimensional objects. Its data structures and algorithms have been used in a broad range of applications: Co...The field of solid modeling has created numerous techniques for unambiguous computer representations of three-dimensional objects. Its data structures and algorithms have been used in a broad range of applications: Computer-Aided Design and Computer-Aided Manufacturing (CAD/ CAM), robotics, computer vision, computer graphics and visualization, virtual reality, etc. This research paper is used to generate process plan from feature-based modeling, based on an integrated geometric modeling system that supports both feature-based modeling and information storage. Present system is developed only for milling components and limited to selective machining features for prismatic components and further implemented for more machining features to develop algorithms for modeling the components through the input of machining features. As a result, feature information is directly available to downstream activities, and feature extraction is no longer needed. The various systematic steps involved in this approach are study of Design, identification of Features, selection of Processes, Tools and Machines, Machining and Inspection [DFPTMMI]. Machining features generated in the design stage are recognized and stored under the Visual Basic control of CATIA software ActiveX interface. Algorithms are developed for individual features and these algorithms are embedded in Visual Basic forms. This system is discussed and suited for 2.5 Dimensional part approach, however, that can be extended to 3 dimensional prismatic part and complex features machining. Finally a process planning chart has been presented as a model process planning.展开更多
基金National Key Research and Development Program of China,Grant/Award Number:2022YFF0904303Beijing Science and Technology Planning Project,Grant/Award Number:Z221100006322003National Natural Science Foundation of China,Grant/Award Number:61932003。
文摘Computer-aided design(CAD)software continues to be a crucial tool in digital twin application and manufacturing,facilitating the design of various products.We present a novel CAD generation method,an agent that constructs the CAD sequences containing the sketch-and-extrude modelling operations efficiently and with high quality.Starting from the sketch and extrusion operation sequences,we utilise the transformer encoder to encode them into different disentangled codebooks to represent their distribution properties while considering their correlations.Then,a combination of auto-regressive and non-autoregressive samplers is trained to sample the code for CAD sequence con-struction.Extensive experiments demonstrate that our model generates diverse and high-quality CAD models.We also show some cases of real digital twin applications and indicate that our generated model can be used as the data source for the digital twin platform,exhibiting designers'potential.
文摘With the progress of computer technology, CAD technique is urgent needed. In this paper, we conduct numerical and theoretical analysis and research on computer aided design technique and novel pattern for electronic architectural drawing and perspective. AUTOCAD drawing soRware because of its versatility and easy entry, in engineering has broad user base, but also because of the basis of general drawing software, often cannot directly use of the existing order efficiently complete professional drawing. We modify the current pattern and introduce our proposed pattern for advancement. The experiment proves the effectiveness of the pattern. In addition, we will conduct more insightful research in the future to nolish the current anoroach.
文摘Purpose: Surgical templates produced by digital simulation and CAD/CAM allow for three-dimensional control of implant placement. However, due to clinical limitations, there are complications during the use of the template. The purpose of this study was to summarize the complications associated with the use of surgical templates for static computer-aided implant surgery. Methods: Complications were collected during the observation period, and then their implant sites were reanalyzed with simulation software. Results: There were 104 cases during the observation period, 5 cases had complications. Mechanical complications were observed in four cases, including three cases in which the frame of the template fractured during implant placement surgery and one case in which the sleeve fell off the surgical template. In one case, there was an error in the planned position. All cases were mandibular molar cases, and all cases of frame fracture were at the free end defect site. All cases had a Hounsfield unit of more than 700 at the implant site, and some of them had a significantly small jaw opening. Conclusion: Although the spread of CAD/CAM surgical templates has made it possible to avoid problems caused by the position of the implant, it has been difficult to avoid fractures in cases of mandibular free end defects with high Hounsfield unit.
基金Supported by the National Natural Science Foundation of China(21576240)Experimental Technology Research Program of China University of Geosciences(Key Program)(SJ-201422)
文摘Aiming to increase the efficiency of gem design and manufacturing, a new method in computer-aided-design (CAD) of convex faceted gem cuts (CFGC) based on Half-edge data structure (HDS), including the algorithms for the implementation is presented in this work. By using object-oriented methods, geometrical elements of CFGC are classified and responding geometrical feature classes are established. Each class is implemented and embedded based on the gem process. Matrix arithmetic and analytical geometry are used to derive the affine transformation and the cutting algorithm. Based on the demand for a diversity of gem cuts, CAD functions both for free-style faceted cuts and parametric designs of typical cuts and visualization and human-computer interactions of the CAD system including two-dimensional and three-dimensional interactions have been realized which enhances the flexibility and universality of the CAD system. Furthermore, data in this CAD system can also be used directly by the gem CAM module, which will promote the gem CAD/CAM integration.
文摘The general computer-aided design （CAD） software cannot meet the mould design requirement of the autoclave process for composites, because many parameters such as temperature and pressure should be considered in the mould design process, in addition to the material and geometry of the part. A framed-mould computer-aided design system （FMCAD） used in the autoclave moulding process is proposed in this paper. A function model of the software is presented, in which influence factors such as part structure, mould structure, and process parameters are considered; a design model of the software is established using object oriented （O-O） technology to integrate the stiffness calculation, temperature field calculation, and deformation field calculation of mould in the design, and in the design model, a hybrid model of mould based on calculation feature and form feature is presented to support those calculations. A prototype system is developed, in which a mould design process wizard is built to integrate the input information, calculation, analysis, data storage, display, and design results of mould design. Finally, three design examples are used to verify the prototype.
文摘Custom-made esthetic finger prostheses, which are used for rehabilitation of patients with missing or impaired fingers, have been fabricated manually. However, such fabrication is time-consuming and requires manual skill. Here we propose a computer-aided method for fabricating finger pros-theses to save time and allow fabrications that do not require considerable manual skill. In this method, the dimensions of a patient’s healthy finger on the contralateral hand are first measured using a caliper. Using these dimensions, a three-dimensional model is constructed for fabricating a prosthesis for the patient’s impaired finger. Using the 3D model, a mold is designed using 3D modeling tools and a computer-aided design system. The resulting mold is then fabricated using a 3D printer. A finger prosthesis is fabricated by pouring silicone resin into the mold. A finger prosthesis for a volunteer was experimentally fabricated according to the proposed method. To evaluate the size and shape of the finger prosthesis, the difference between the finger prosthesis and the original finger of the volunteer was analyzed. Because the average difference between them was 0.25 mm, it was concluded that the proposed method could be used to fabricate a finger prosthesis of adequate size and shape.
文摘The field of solid modeling has created numerous techniques for unambiguous computer representations of three-dimensional objects. Its data structures and algorithms have been used in a broad range of applications: Computer-Aided Design and Computer-Aided Manufacturing (CAD/ CAM), robotics, computer vision, computer graphics and visualization, virtual reality, etc. This research paper is used to generate process plan from feature-based modeling, based on an integrated geometric modeling system that supports both feature-based modeling and information storage. Present system is developed only for milling components and limited to selective machining features for prismatic components and further implemented for more machining features to develop algorithms for modeling the components through the input of machining features. As a result, feature information is directly available to downstream activities, and feature extraction is no longer needed. The various systematic steps involved in this approach are study of Design, identification of Features, selection of Processes, Tools and Machines, Machining and Inspection [DFPTMMI]. Machining features generated in the design stage are recognized and stored under the Visual Basic control of CATIA software ActiveX interface. Algorithms are developed for individual features and these algorithms are embedded in Visual Basic forms. This system is discussed and suited for 2.5 Dimensional part approach, however, that can be extended to 3 dimensional prismatic part and complex features machining. Finally a process planning chart has been presented as a model process planning.
