• Title/Summary/Keyword: 원통형 정전용량 변위센서

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Effects of Geometric Errors on the Measurement of Error Motions of Rotor with the Cylindrical Capacitive Displacement Sensor (형상오차가 원통형 정전용량 변위센서의 축 회전오차의 측정에 미치는 영향)

  • 안형준;장인배;한동철
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.487-490
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    • 1995
  • This paper discisses the effects geometric errors on the measurement of error motions of rotor with the cylindrical capacitive displacement sensor. Analytic model of the measuring process with this sensor is derived and this model shows that the effect of geometric errors of sensor is larger than that of rator on the measurement of error motions of rotor. The computer simulation shows effect of periodic errors in this sensor on the measuring orbit.

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New Design of Cylindrical Capacitive Sensor for On-line Precision Control of AMB Spindles (자기베어링의 실시간 정밀제어를 위한 원통형 정전용량 변위센서의 새로운 설계)

  • Jeon, Soo;Ahn, Hyeong-Joon;Han, Dong-Chul
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.548-553
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    • 2000
  • A new design of cylindrical capacitive sensor(CCS) for the displacement measurement of precision active magnetic bearing(AMB) spindle is presented in this paper. This research is motivated by the problem that existing 4-segment CCS is still sensitive to the $3^{rd}$ harmonic component of the geometric errors of a rotor. The procedure of designing new CCS starts from the modeling and error analysis of CCS. The angular size of CCS is set up as a design parameter, and new 8-segment CCS is introduced to possess an arbitrary angular size. The optimum geometry of CCS to minimize the effect of geometric errors is determined through minimum norm approach. Experimental results with test rotors have confirmed the improvement in geometric error suppression.

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Automatic and precise calibration of 4-channel cylindrical capacitive displacement sensor (4채널 원통형 정전용량 변위센서의 자동ㆍ정밀 검보정)

  • 김종혁;김일해;박만진;장동영;한동철;백영종
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.04a
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    • pp.387-393
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    • 2004
  • General purpose of cylindrical capacitive displacement sensor(CCS) is measuring run-out motion and deflection of rotor. If CCS has narrow sensing range, its sensitivity coefficients must be calibrated precisely. And x, y component of CCS output can be coupled. In this research, CCS calibration procedure is automated with automatic calibration program and PC-controlled stage. And, coupled-terms of CCS signals were removed and the errors between measured position and mapped CCS signal were reduced obviously by sensitivity matrix that linearly.

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A Novel Cylindrical Capacitive Sensor for both Radial and Axial Motion Measurements (반경 방향 및 축 방향 운동 동시 측정을 위한 새로운 원통형 정전용량 변위센서)

  • Ahn H.J.;Kim J.H.;Jang D.Y.;Han D.C.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.276-279
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    • 2005
  • This paper presents a novel cylindrical capacitive sensor (CCS) for both radial and axial motion measurements. Although the new CCS has almost the same geometric configuration as the conventional CCS, the unused axial area of the CCS is utilized to measure the axial motion of the rotor, which can affords more compact design and reduction of the system complexity. First, a theoretical model of the proposed CCS is derived. Based on the derived theoretical model, compensation methods to decouple the radial and axial motion measurements are proposed. In addition, error analysis is performed and a design rule is proposed to guarantee the same accuracy in measuring both radial and axial motions. Finally, a test rig and electronics for the proposed CCS are built and the effectiveness of the proposed CCS is verified with experiments and simulations.

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On-line Cutting Force Estimation by N[ensuring Spindle Displacement in High-Speed Milling Process (고속 밀링 가공 시 주축 변위 측정을 통한 절삭력의 실시간 감시)

  • Kim J.H.;Kim J.H.;Kim I.H.;Ahn H.J.;Jang D.Y.;Han D.C.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.133-134
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    • 2006
  • A cylindrical capacitive displacement sensor (CCS) was developed and applied for monitoring end milling processes. Dynamic characteristics of a spindle-assembly were measured using the CCS and a designed magnetic exciter. The technique to extract the spindle displacement component caused only by cutting from the measured signals using the CCS was proposed in the paper. Using CCS signals and FRF (Frequency Response Function) derived from dynamics of the spindle tool system, dynamic cutting forces are estimated quantitatively.

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Chatter Monitoring of Milling Process using Spindle Displacement Signal (주축 변위 신호를 이용한 밀링가공의 채터 감시)

  • Chang, Hun-Keun;Kim, Il-Hae;Jang, Dong-Young
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.16 no.6
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    • pp.140-145
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    • 2007
  • To improve productivity of a metal cutting process, it is required to monitor machining stability in real time. Since cutting environment is harsh against sensing conditions due to vibration, chip, and cutting fluid, etc., it is necessary to develop a robust and reliable sensing system for the practical application. In this work, a chatter monitoring system was developed and its effectiveness was proved. Spindle displacement caused by cutting was selected as a main monitoring parameter. A cylindrical capacitive displacement sensor was adopted. Chatter frequencies were identified through modal analysis. To quantify chatter vibrations, chatter correlation coefficient was introduced. The identification of the monitoring system showed a good agreement with the result of experiment.