System for computer-aided cavity layout design for die-casting dies

Data exchange between different computer-aided design (CAD) systems is a major problem inhibiting information integration in collaborative engineering environments. Existing CAD data format standards such as STEP and IGES enable geometric data exchange. However, they ignore construction history, features, constraints, and other parametric-based CAD data. As a result, they are inadequate for supporting modification, extension and other important higher-level functionality when accessing an imported CAD model from another CAD system. Achieving such higher-level functionality therefore often requires a time-consuming, error-prone, tedious process of manually recreating the model in the target CAD system. Based on techniques adapted from programming language research, this paper presents an approach to exchanging parametric data between CAD systems using formally-defined conversion semantics. We have demonstrated the utility of our approach by developing a prototype implementation that automates the conversion of 2D sketches between two popular CAD systems: Pro/ENGINEER and SolidWorks. We present examples showing that our approach is able to accurately convert parametric CAD data even in cases where models were constructed using operations from the source CAD system that have no direct counterpart in the target CAD system. Although the case study focuses on 2D interoperability, our approach provides formal foundations for supporting 3D and semantic interoperability between CAD systems.

This study examines the potential of computer-aided design (CAD) systems equipped with artificial intelligence (AI) in reducing the workload of dental technicians. We aimed to compare the accuracy and design time of crowns designed using conventional CAD with those designed using AI-equipped CAD. Abutment tooth models of a maxillary right second premolar (FDI classification #15) and a maxillary left first molar (FDI classification #26) were mounted on a dental model to form the master model. Stereolithography data were acquired using an intraoral scanner, and five dental technicians designed one crown each for #15 and #26 using both conventional and AI-equipped CAD systems. With the #15 and #26 crowns, six measuring points were established for comparing the accuracy of the occlusal surfaces and design time of the crowns designed by the two CAD systems. The occlusal surfaces were also compared for the buccal and palatal sides. The accuracy of the occlusal surface was 275.5 ± 116.8 µm and 25.7 ± 13 µm for the conventional CAD and AI-equipped CAD systems, respectively. For the buccal and palatal surface comparisons, the conventional CAD system revealed larger misfits on the palatal side for both #15 and #26, with significant differences observed. No significant differences were noted with the AI-equipped CAD system. The AI-equipped CAD resulted in significantly faster design time for both #15 and #26. The AI-based CAD system significantly reduced design time and enabled the fabrication of uniform crowns regardless of the dental technician's experience and skill.

A virtual reality (VR) interface to a feature-based computer-aided design (CAD) system promises to provide a simple interface to a designer of mechanical parts, because it allows intuitive specification of design features such as holes, slots, and protrusions in three-dimensions. Given the current state of a part design, the designer is free to navigate around the part and in part cavities to specify the next feature. This method of feature specification also provides directives to the process-planner regarding the order in which the features may be manufactured. In iterative feature-based design, the existing part cavities represent constraints as to where the designer is allowed to navigate and place the new feature. The CAD system must be able to recognize the part cavities and enforce these constraints. Furthermore, the CAD system must be able to update its knowledge of part cavities when the new feature is added. In this paper, (i) we show how the CAD system can enforce the aforementioned constraints by exploiting the knowledge of part cavities and their adjacencies, and (ii) present efficient methods for updates of the set of part cavities when the designer adds a new feature.

This paper describes computer-aided design for quality — a new, cost-effective methodology for designing high-quality, manufacturable products using computer-aided design (CAD) systems. Traditionally, CAD systems have been used to simulate a producT's characteristics for a given set of values for the design parameters. Thus, designers could study the effects of design choices on a producT's quality before production started. Recent advances in computer hardware technology have given CAD systems increasingly complex and accurate simulation capabilities, permitting simultaneous examination of the effects of changes in many design parameters. But CADQ goes a step further. It provides powerful, statistical, model-fitting methods and optimization techniques that extend the traditional use of CAD systems. Given a set of quality-performance measures, a designer now can interactively pursue a producT's optimal design, while considering manufacturing constraints and characteristics of the customers' environment. Through a case study, we show the application of CADQ to integrated-circuit design.

Method for blending edges of a geometric object in a computer-aided design system

Nowadays, companies are developing more and more collaborative projects, and hence the need to exchange data with many partners, contractors, subcontractors, suppliers, and customers. So, to establish successful collaborations, they must ensure the relevance, coherence, and especially the security of exchanged data. But the Computer-Aided Design (CAD) systems still have gaps that need to be corrected in order to improve the productivity of the design process: they offer few solutions to maintain data consistency within the digital model. Adding to that poor management of changes, the user has to manage the consequences of each change manually. This research explores the role of mates’ assembly, as defined in CAD systems, as a key to maintaining the links between parts in the assembly. In this work, we propose the CAD Assembly Management Model that is based on reference elements, in order to maintain mates between CAD entities when a part is modified by a partner and then reinserted into the assembly CAD, and then propagate changes.

The profile-based features of a mechanical computer aided design (CAD) system commonly have complicated shapes because of the guide curve, which is free-form type. However, while considering interoperability between different CAD systems, due to this kind of free-form guide curve, it is difficult to represent the corresponding feature shape in another CAD system, for example, ship CAD systems usually use relatively simple shape primitive to represent shape. Thus, in this paper, we propose a straightforward algorithm to represent profile-based features that is based on guide curve approximation using line and arcs segments. In addition, the solid alignment and filling operation are also given to complete the process of solid model reconstruction, and we use several test cases to demonstrate the effectiveness of the proposed method.

SUMMARY In this paper the basic ideas behind an original computer-aided design (CAD) system for designing electric machinery is described. The framework in which all modules are implemented is a powerful interactive graphics system. The user thus continuously maintains control over the entire design through graphical communication. Because the CAD system is essentially conceived as a closed loop process, it supports a flexible and progressive design, allowing many trials-and-errors. Basically, the CAD system comprises two nested loops. In the outer loop, the adaptive modelling process, the geometry of the machine is controlled. The resulting geometric model maintains a dual representation of the machine. The boundary representation accepts all graphical actions of the interactive drafting system and guarantees compatibility with external systems through standards. The material region representation, on the other hand, is required for the purpose of calculation. The geometric model is hierarchically organi...

A computer-aided design (CAD) system has been developed having an automatic computing capability for optimum driving current I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">fc</inf> (central value of I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</inf> ) and an operating margin as a function of ambient temperature and a number of pairs for delta noise. The worst driving conditions are clarified for two cases : the case of cross-temperature operation (WRITE at one temperature and RETRIEVE or READ at another) and the case of unbalanced drive. The results are adopted as the main algorithm in this CAD system. Input data to this system are <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dV_{1}, dV_{0}, \DeltaN</tex> (the delta noise) of 10-200 pieces of sampled core. Outputs of the system are various kinds of graphs, such as I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">fc</inf> , and upper and lower limits for driving current as a function of ambient temperature. The two points of this paper are the establishment of the worst driving conditions considering the cross-temperature effect and completion of a CAD system.

The following paper addresses the human factors considerations which affect the hardware, software, and human interface in a computer aided design (CAD) system. A table is produced which shows the allocation of taks and responsibilities for the human and computer in a CAD system. Future research directions for human involvement in a CAD system are discussed while an expert system for design tasks is proposed.

This paper describes a structural design system for 3D drawing dies based on functional features using a minimum set of initial information. In addition, it is also applicable to assign the functional features flexibly before accomplishing the design of a solid model for the main parts of a drawing die, such as upper die, lower die, and blank holder. The initial information includes blank sizes, work strokes, die faces, punch open lines, and press data. The proposed system integrated the design knowledge of drawing die into functions of 3D computer-aided design (CAD) software to automate design and to shorten design time. This design system is constructed on a PC and integrated with a Pro/ENGINEER CAD system including feature selector, shape calculator, model generator, design coordinator, and user interface. The proposed system is demonstrated using the example of designing a drawing die for the roof panel of a vehicle within 1 h. The results reveal that it can dramatically improve the design quality and can save both time and costs with excellent design quality.

Future prospects of computer-aided design (CAD) – A review from the perspective of artificial intelligence (AI), extended reality, and 3D printing

An evaluation of the relationship between management practices and computer aided design technology

The design of production and logistic systems is a process of managing both technical and organisational variants in order to identify the best solution for a given system. This paper discusses design issues of production systems that are applied to an internal logistic system in the automotive industry. As far as the production systems design (PSD) is concerned, three basic classes of software tools usually pertain: computer-aided design (CAD), process simulation, and information systems. However, these software tools have been used with low levels of integration. Vik et al. (2010b, 2010c) proposed integrating these software resources in production systems and developed an advanced tool called integrated design of systems (IDS). The proposed IDS tool involves a wide set of functions for the most common tasks of PSD, from conceptualisation to implementation, including systems analysis (P-Q, cluster, and material flow analysis), automatic generation of simulation models, generation of alternatives for the layout of facilities and factories, material flows display, transportation system design, and iterative buffer size specification. The IDS approach takes advantage of simulation, CAD systems, and their integration. This paper will demonstrate the concept and functionalities of the proposed tool in a real industrial case study.

The development of the orthotopically positioned totally implantable artificial heart (TAH) requires knowledge of the detailed structure of the thoracic cavity and the relative position of remnants to guide the design of the blood pump system. To adjust anatomical fit, a three-dimensional anatomical fitting simulator (AFS) for the TAH was developed with three-dimensional image reconstruction of magnetic resonance imaging (MRI) and a computer-aided design (CAD) system. The wire-frame model of the spatial geometry of the aortic arch and pulmonary bifurcation was extracted from electrocardiogram (ECG)-gated MR images of the human chest. A solid model of the Korean TAH with adjustable inlet/outlet ports including atrial cuffs and arterial graft, was generated with a MicroStation (Intergraph, Huntsville, AL, USA) CAD system. The chest cavity model and TAH model were integrated in the AFS to select the accurate position and direction of the inlet/outlet port of the implantable TAH. The orthotopic position of the implantable TAH, the direction and curvature of arterial grafts, and the diameter and inflow direction of atrial cuffs in the final TAH design were confirmed with the AFS. The newly developed AFS offers a versatile method for the development of the implantable TAH.