Byung Chul Kim

An XML-Based Macro Data Representation for a Parametric CAD Model Exchange

AbstractA macro-parametric approach, which is a history-based method of parametric CAD model exchange, has recently been proposed. CAD models can be exchanged in the form of a macro file that comprises a sequence of modeling commands. As a set of event-driven commands, a standard macro file can transfer the designer intent such as parameters, features and constraints. Moreover, it is suitable for a network environment because standard macro commands are open and explicit, and the data size is small. This paper introduces XML technology to represent the macro-parametric exchange. Using XML to represent macro-parametric commands enables the management of a large amount of dynamic content, Web-enabled distributed applications, and the inherent characteristics of structure and validation.

Integration of history-based parametric translators using the automation APIs

In this paper, a history-based parametric method was proposed and implemented. However, the size of each translator that exchanges the feature and parametric information tends to be large, due to the implementation of duplicated functions. Furthermore, because a history-based parametric translator uses a procedural model as a neutral format, it requires a geometric modelling kernel to generate an internal explicit geometric model. To solve this problem, we implemented a shared integration platform, TransCAD system, which separates translators from a neutral file. The translators for commercial CAD systems can communicate with only TransCAD. To support communication with TransCAD, we exposed the functions of TransCAD by using Automation APIs developed by Microsoft. Each translator uses Automation APIs of TransCAD either to translate a parametric CAD model from the sending CAD system into XML format or to translate from the XML format into the model of the receiving CAD system. This paper introduces the TransCAD system and its function for the exchange of feature and parametric models.

Crystallization monitoring in supersaturated solution with a quartz crystal sensor

Abstract The degree of supersaturation is an important measure for the operation of crystallization processes, because it is directly related to the control of crystal size distribution and shape. A conventional technique utilizing solution composition and temperature has a variety of problems caused from the measurement error and the handling of analyzing samples. A monitoring system of the supersaturation using a quartz crystal sensor is proposed here, and its performance is examined applying different manipulations of coolant temperature. The experimental outcome and photographic examination indicate that the measurements of resonant frequency and resistance of the sensor can be used for the prediction of the formation and growth of solid crystal from the crystallization process. The monitoring system eliminates the intrinsic error source of the conventional system to give the improved measurement and on-line application availability.

Simplification of feature-based 3D CAD assembly data of ship and offshore equipment using quantitative evaluation metrics

In the design process for ship outfitting and offshore plants, an equipment catalog database is compiled in order for shipyards to reutilize data effectively. However, the current procedure for building such a catalog causes wastage of time because the modelers in the shipyard must perform manual modeling of the 3D CAD data in order to decrease the size of 3D CAD data and adopt a different level of detail (LOD) depending on the purpose of its use. This problem arises because equipment suppliers are not willing to give all of their 3D CAD data to shipyards, out of fear of the loss of intellectual property. Moreover, the 3D CAD data of equipment suppliers have a high LOD, while a shipyards 3D CAD data have a relatively low LOD. Therefore, it is necessary to introduce an automated method to simplify the 3D CAD assembly data for equipment that is received from the equipment supplier. In addressing this problem, this study first proposes criteria for a simplification process and quantitative evaluation metrics for the simplification of 3D CAD assembly data, considering the characteristics of equipment data in the shipbuilding industry. Based on these findings, a simplification system was developed, and, four experimental test cases that were conducted on-site were used to verify the proposed system. The results showed that the data to be stored could be reduced to at least 25% of the original 3D CAD assembly data while ports, outer boundaries, and connectivity between CAD parts could be maintained. Display Omitted Shipyards need simplified equipment 3D CAD assembly data for system-level design.Three simplification operations applicable for 3D CAD assembly data are developed.Evaluation metrics considering multiple simplification criteria are proposed.The evaluation metrics allow discriminatory priority of specific criteria.

A procedural method to exchange editable 3D data from a free-hand 2D sketch modeling system into 3D mechanical CAD systems

In the concept development phase, a designer wants to rapidly create a products overall shape and user interfaces by making simple sketches, known as thumbnail sketches, to evaluate ideas and possibilities. Free-hand 2D sketch systems are regarded as a computerized tool for making thumbnail sketches. After the concept development phase, subsequent editing of the 3D data reconstructed from a free-hand 2D sketch with a 3D mechanical CAD system in the detail design phase is indispensable because inaccurate dimensions are inherent in a free-hand 2D sketch. For this reason, we present a new method to translate 3D data reconstructed from a free-hand 2D sketch into an editable form that reflects design intent so that the translated data can be directly used in 3D mechanical CAD systems. The feasibility of the proposed method has been demonstrated through experiments with prototype systems.

Technical note: Parametric exchange of round shapes between a mechanical CAD system and a ship CAD system

Interoperability among heterogeneous Computed-Aided Design (CAD) systems is an important issue. With the advent of global outsourcing, collaborative design has expanded from inside the enterprise to parts suppliers. This paper introduces a method for design data exchange between shipyards and equipment suppliers. These parties usually use different CAD systems, because they want to select the most suitable one for their jobs. CAD systems provide modeling functionality that is based on distinct modeling units. Therefore, to exchange design data, one must map between these two distinct sets of modeling units. Some modeling units can be directly mapped and converted, and other modeling units that cannot be directly mapped (such as the fillet feature in a mechanical CAD system) are converted by the indirect mapping procedure proposed in this paper. The proposed method is demonstrated with case studies between TransCAD and the AVEVA Marine system.

Special section on CAD/Graphics 2013: Feature-based simplification of boundary representation models using sequential iterative volume decomposition

When computer-aided design (CAD) models generated in the design phase are used for engineering activities such as engineering analysis, distributed collaborative design, and virtual prototyping, a process for simplifying the CAD models is needed. In this study, a feature-based simplification method of boundary representation (B-rep) models using sequential iterative volume decomposition is proposed. This method generates a feature-based model from a B-rep model by sequentially and iteratively applying the four volume decomposition methods (fillet, round, and chamfer decomposition; wrap-around decomposition; volume split decomposition; and cell-based decomposition). Then, feature-based simplification is applied to the generated feature-based model. To demonstrate the proposed method, a prototype system is implemented, and experiments with test cases are performed. Based on the experimental results, we verified that the proposed method successfully simplified B-rep models.

A method to exchange procedurally represented 2D CAD model data using ISO 10303 STEP

Procedural models have the advantage of being easy to edit simply by changing the values of the parameters of their constructional operations. Such models are said to embody design intent, in the sense that modifications to them conform to the method of creation used by their original creator. They also comply with any constraints implied by the particular constructional operations used. This paper introduces the development and standardization process of the ISO 10303-112 specification and describes the concept of procedural 2D modeling, a method of representing procedural 2D CAD models in STEP in harmony with other STEP resources. The feasibility of procedural 2D modeling commands for the exchange of procedurally represented 2D CAD model data is demonstrated through an experiment where procedural 2D CAD model data in neutral form generated with an in-house 2D modeling system are translated to and modified in a commercial 3D mechanical CAD system.

Web Service with Parallel Processing Capabilities for the Retrieval of CAD Assembly Data

Since CAD data is used as master data throughout the lifecycle of a product, it is important to provide a means for efficiently sharing CAD data among systems used for collaborative product development. Web Services, a type of distributed object technology, is adequate for this purpose; in a previous study [7], the authors proposed the architecture of Web Services for CAD (WSC) for the retrieval of CAD data. CAD data are classified into CAD assembly and part data. Since product design is typically modeled in the form of CAD assembly data, it is worth to consider this application when implementing a service for CAD data retrieval. In this study, the authors first propose a concept of parallel Web Service, which is an extension of WSC and whose goal is the rapid retrieval of CAD assembly data. They then discuss the technical details that can lead to its realization. Finally, experimental results regarding the performance of assembly data retrieval by the parallel Web Service are presented and compared with analogous performance by a single Web Service.

Toward standardized exchange of plant 3D CAD models using ISO 15926

Abstract Plant three-dimensional (3D) computer-aided design (CAD) models typically consist of logical configuration, equipment specifications and ports, and 3D shapes. Because 3D CAD models are used as master information throughout a plant’s entire lifecycle and many stakeholders are involved in such lifecycle, providing a method for sharing plant 3D CAD models among various stakeholders is very important. Standard 15926 from the International Organization for Standardization (ISO 15926) is a family of standards that is intended to support the sharing and integrating of all information during the life of a process plant. Therefore it is important for ISO 15926 to support plant 3D CAD models. In order to address this issue, this study investigates a standardized method to exchange plant 3D CAD models using ISO 15926. Information requirements regarding plant 3D CAD models are established, and then ISO 15926 reference data (classes, attributes, and templates) are extended to cover information requirements. For demonstration of the proposed method, we developed a prototype platform where plant 3D CAD models in ISO 15926 are loaded and retrieved.