• Korean Journal of Computational Design and Engineering
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• v.13 no.4
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• pp.255-264
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• 2008

Research that reconstructs a 3D model from a freehand 2D sketch has gained attention since 1990s, when data integration in the CAD/CAPP/CAM/CNC chain was an important issue. However, 2D sketches in the conceptual design phase have not been integrated with the downstream CAD/CAPP/CAM/CNC chain. In this paper, we present a method to interface a freehand sketch modeling to commercial CAD systems by mapping a sketch modeling history to the macro parametric history. We use an extended ISO10303-112 standard to represent the modeling history in a gestural modeling system and translate sketch files to neutral macro files. Macro parametric translators are used to translate netural macro files to commercial CAD files.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.26-32
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• 2002

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.217-224
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• 2003

ISO 14649 is a new interface (or language) standard for the CAD-CAM -CNC chain, currently under establishment by ISO TC184 SCI and SC4 . Upon completion, it will replace ISO 6983, so called M amp; G codes used for CNC since 1950' s. As the new language is being established, a new CNC controller called STEP-CNC (STEP­compliant CNC), capable of carrying out various intelligent tasks using the new language as an input, receives worldwide attention. In this paper, we present a distributed architecture for STEP-NC system based on the generic paradigm of STEP-NC. The STEP-NC system is consisted of 3 sub-systems: 1) CGS (Code Generation System), 2) CES (Code Edit System), and 3) ACS (Autonomous Control System). Also presented in this paper is algorithm for delta volume decomposition, a crucial algorithm for developing CGS. First method is based on the cutting tool and the second method is based on the turning features commonly used in the shop floor. An illustrative example is given to compare the two methods, and to illustrate usage scenario of the delta volume in the turning STEP- NC system under development.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.257-264
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• 2004

분산 제조 시스템간의 협업을 가능케 하는 e-Manufacturing paradigm 의 성공을 위해서는 CAD-CAM-CNC chain 의 제조 분야뿐만 아니라 SCM, ERP, CRM 등의 상위 시스템과의 제품 및 가공 정보의 원활한 흐름이 필수적이다. STEP 과 STEP-NC 는 이를 해결할 표준으로 자리매김 할 것으로 기대되고 있다. 본 논문은 STEP-NC 의 국내 promotion 차원에서 참고문헌 [1]의 밀링용 파트프로그래밍 소개에 이어: 1) 선반용 데이터 모델, 2) 선반용 파트 프로그램의 작성 방법, 3) XML 을 이용한 파트 프로그램의 표현 방법들을 소개하고, 4) STEP-NC 기반의 생산 환경 구축을 위한 방안을 기술하였다.

• Korean Journal of Computational Design and Engineering
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• v.12 no.4
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• pp.283-297
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• 2007

Seamless data integration in the CAx chain of the CAD/CAPP/CAM/CNC has been achieved to a high degree, but research concerning the transfer of data from conceptual sketches to a CAD system should be carried out further. This paper presents a method for reconstructing a 3D model from a freehand sketch. Sketch-based modeling research can be classified into gestural modeling methods and reconstructional modeling methods. This research involves the reconstructional modeling method. Here, Mitani's seminal work, designed for box-shaped 3D model using a predefined template, is improved by leveraging a relational template and specialized for automotive design. Matching between edge graphs of the relational template and the sketch is formulated and solved as the assignment problem using the feature vectors of the edges. Including the stroke preprocessing method required to generate an edge graph from a sketch, necessary procedures and relevant techniques for implementing the template-based modeling method are described. Examples from a working implementation are given.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.208-216
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• 2003

ISO 14649 (data model for STEP-NC) is a new interface scheme or language for CAD-CAM-CNC chain under established by ISO TC184 SCI. Up to this point, the new language is mainly made for milling and turning, and other processes such as EDM will be completed in the future. Upon completion, it will be used as the international standard language for e-manufacturing paradigm by replacing the old machine-level language, so called M&G code used since 1950's. With the rich information contents included in the new language, various intelligent functions can be made by the CNC as the CNC knows what-to-make and how-to-make. In particular, On-Machine Inspection required for quality assurance in the machine level, can be done based on the information of feature­based tolerance graph. Previously, On-Machine inspection has been investigated mainly for milling operation, and only a few researches were made for turning operation without addressing the data model. In this thesis, we present a feature-based on-machine inspection process by the 4 Tasks: 1) proposing a new schema for STEP-NC data model, 2) converting the conventional tolerance scheme into that of STEP-NC, 3) modifying the tolerance graph such that the tolerance can be effectively measured by the touch probe on the machine, and 4) generating collision-free tool path for actual measurement. Task 1 is required for the incorporation of the presented method in the ISO 14649, whose current version does not much include the detailed schema for tolerance. Based on the presented schema, the tolerance represented in the conventional drafting can be changed to that of STEP-NC (Task 2). A special emphasis was given to Task 3 to make the represented tolerance accurately measurable by the touch probe on the machine even if the part setup is changed. Finally, Task 4 is converting the result of Task into the motion of touch probe. The developed schema and algorithms were illustrated by several examples including that of ISO 14649 Part 12.