• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.999-1002
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• 2002

Cylindrical Cam Mechanism is widely used in the fields of industries, such as machine tool exchangers, textile machinery. This paper proposes a method for manufacturing of cylindrical cam in Multi CNC machining center. Multi CNC machining center has two different types depending on the tilting axis. For the manufacturing procedures. in this paper the location and the orientation of cutter path are defined from shape design data of cam. The integral NC code fur the both types of multi-axis CNC machining center can be created using the coordinates mapping between design coordinates and work coordinates. Finally, CAD/CAM program is developed on $C^{＋＋}$ language. This program can display manufacturing and kinematics simulation, which can make integral NC code for multi-axis CNC machining center of two types.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.5 s.182
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• pp.93-102
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• 2006

This paper proposes a controller design analysis for three-axis CNC systems considering both contouring and tracking performance. The proposed analysis inclusively combines axial controllers for each individual feed drive system together with cross-coupling controller at the beginning design stage as an integrated manner. These two controllers used to be separately designed and analyzed since they have different control objectives. The proposed scheme includes a stability analysis for the overall control system and a performance analysis in terms of contouring and tracking accuracy. Computer simulation is performed and the results show the validity of the proposed methodology. Further, the results can be used as a basic guideline in systematic and comprehensive controller design for multi-axis CNC systems.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.15-16
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• 2009

• Journal of the Korean Society for Precision Engineering
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• v.26 no.4
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• pp.16-22
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• 2009

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.809-814
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• 1991

기존의 CNC Controller를 재구성하면 제어성과 절삭성의 재고에 큰 효과를 낼 수 있다. 현실적으로 시스템의 재구성은, 가) 시스템의 재구성으로 2축 CNC 기계를 다축으로 전환시킬 수 있고, 나) 모터의 직접제어에 의한 G-code 작성과정의 생략이 가능하며, 다) NC 동작의 제어가 소프트웨어로 (C 언어) 이루어 지기 때문에 사용자환경에 맞도록 고객화가 가능한 강점이 있다. 나아가서는 형상의 정의에서 NC 기계동작의 제어 및 온라인 모니터링에 이르는 전과정을 소프트웨어로 일식화 시킬 수 있는 통합 NC 시스템의 구현이 가능하다. 본 논문에서는 이러한 목적으로 연구되고 있는 INCS(Integrated NC System)의 개발현황을 소개한다. INCS는 PC-286, NC Controller, Drive Amplifier, Sensing Device의 하드웨어 시스템과 CAD, CAM 및 CNC 기능을 수행하는 소프트웨어 시스템으로 구성되어 있다. 그래픽 시뮬레이션 및 실제 절삭을 통하여 개발된 방식의 유효성과 효율성을 설명한다.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.2
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• pp.168-175
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• 2011

Contouring accuracy of CNC machine tools is very important for high-speed and high-precision machining. In particular, large contour error may occur during corner tracking. In order to reduce the corner contouring error, acceleration and deceleration control or tool-path planning methods have been suggested. However, they do not directly control the corner contouring error. In the meantime, network servo systems are widely used because of their easiness of building and cost effectiveness. Communication latency between the master controller and servo drives, however, may deteriorate contouring accuracy especially during corner tracking. This paper proposes a control strategy that can accurately calculate and directly control the corner contouring error. A prediction control is combined with the above control to cope with communication latency. The proposed control method is evaluated through computer simulation and experiments. The results show its validity and usefulness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1157-1163
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• 2009

In order to improve in quality and productivity using the CNC machine tools, it has been endeavored to elevate production process by adding supplementary axes(2 axes) to 2,3 axial CNC machine tools. It is because the movement between the progress of work in processed goods is remarkably decreased more than that of general CNC machine tools that productivity improvement with precision maintenance can be improved. VBScript in CAD/CAM is applied to utilize CNC machine tools added supplementary axes so that Multi-axial &Multi-process manufacturin g program can be conveniently drawn up. However, there is generally much skilful work and operation by the manual program of CAD(2.5D) and CNC machine tools in the filed. As a result of conducting an experiment by COM-filing VBScript at the spot of Insert Tip for milling Face Cutter in CAD/CAM Software(2.5D), it was not only timesaving to draw up program but also more convenient than complicated Multi CAD/CAM Software to approach and possible to program various products instantaneously.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.137-138
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• 2006

This paper proposes a controller design analysis for three-axis CNC systems considering both contouring and tracking performance. The proposed analysis inclusively combines axial controllers for each individual feed drive system together with cross-coupling controller at the beginning design stage as an integrated manner. These two controllers used to be separately designed and analyzed since they have different control objectives. The proposed scheme includes a stability analysis for the overall control system and a performance analysis in terms of contouring and tracking accuracy. Computer simulation is performed and the results show the validity of the proposed methodology.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.12
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• pp.55-61
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• 2009

Machining systems have been evolved to produce more detailed products of high added value. This has been possible, in large part, due to the development of highly accurate multi-axis CNC machine tools. The conventional CNC of machine tools has individual axis controllers to maximize tracking performance. On the other hand, cross-coupling controllers can be integrated into the conventional CNC to enhance contouring performance. For this multi-axis cross-coupling control system, it is necessary to automatically adjust the controller gains depending on operating conditions and/or other external conditions from an optimization perspective. This paper proposes automatic modeling of feed drive systems that minimizes the difference in behavior between the system model and the actual system. Based on the modeling, an integrated auto-tuning method is also proposed to improve both tracking and contouring accuracy of a 3-axis cross-coupling control system as well as users' convenience. The proposed methods are evaluated by both simulation and experiments.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.2
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• pp.79-83
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• 2001

A verification of multi-spindles drilling NC data is presented. The drilling of multi-spindles can offer productivity over three times as fast as that of single spindle. The most important things in machining tube sheet are precision of hole position and machining time. The drilling of multi-spindles has difficulties in controlling many motors to drive spindles and assign a correspondent number to each spindles. Multi-spindles drilling has different codes from CNC milling ; many subroutines, assignment of spindle, and so on. The conventional method, which inspects the NC code of the drilling, is to drill holes on a thin plate or tube sheet previously. The method results in low productivity because it consumed long machining time and welding for correction. This paper describes details of multi-spindles NC code and operation of multi-spindles drilling machine. A verification software of the multi-spindles drilling NC code is developed on the details.