• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.729-733
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• 1997

Due to the variety of disturbance, it is not ease to accomplish the in-process detection of weld line with non-contact sensor. To get around this difficulties problem develop an automatic seam tracking weld system, the reliable signal processing algorithm has been recommanded. In this research, laser displacement sensor is applied as a seam finder in the automatic tracking system. The sensor is controlled by a dc servo motor which is mounted at X-Y moving table. X-Y moving table manipulated by an ac servo motor controls the position and velocity of the welding torch. First, X-Y table moves to Y-axis to search the welding joint feature before starting the welding, and welding joint is from the scanning data and weighting factor for each other. Second, weld line is determined using proposed signal processing algorithm during welding process. Form the experimental results, we could see the possibility that laser displacement sensor with procesed algorithm can be used as a seam finder in welding process under the severe noise (spatter,arc light etc.) condition

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.79-82
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• 1997

The current from the feed motor of a machine tool contains substantial information about the machining state. There have been many researches that investigated the current as a measure for the cutting forces. However it has not been reported that indirect measurement of the cutting forces from the current of the feed motor at rest is possible. The cutting force normal to the machined surface influences the machined surface of the workpiece, which makes it necessary to estimate this force to control the roughness of the machined surface. But the unpredictable behavior of the current prevents applying the current to prediction of the cutting state. In this paper, empirical approach was conducted to resolve the problem. Also parametric adaptive and fuzzy logic control strategies are applied to the force regulation problem. As a result, the current is shown to be related to the accumulation of the infinitesimal rotation of the motor, and besides the unpredictable behavior of the current is shown to be caused by the relationship. Subsequently the relationship between the current and the cutting force is identified, and it is presented that control of machined surface using the current of the feed motor at rest is possible.

• 한국산학기술학회논문지
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• 제6권5호
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• pp.432-438
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• 2005

본 논문에서는 반도체 제조를 위한 AC 서보 모터의 고정도 위치 제어에 관하여 연구하였다. 제어기는 150 MIPS의 고속 처리가 가능한 Tl사의 차세대 모터 제어용 DSP TMS320F2812를 이용하여 컨트롤러를 구성하였으며, 2,500 PPR 분해능의 광학식 증분형 엔코더가 장착 된 100W 용량의 PMSM을 위치 제어 하였다. 위치 제어기를 구성하기 위하여 속도 제어기와 전류 제어기를 하위 루프로 구성하였으며, 회전형 엔코더 4체배 된 신호를 이용하여 최대 10,000 PPR의 위치 제어를 수행 하였다. 이로부터 보다 많은 PPR을 지원하는 엔코더에서도 같은 방법으로 고정도 위치제어가 가능할 것이다.

• 방사성폐기물학회지
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• 제5권4호
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• pp.309-322
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• 2007

이 논문은 사용후핵연료 차세대관리공정(ACP)에 사용되는 주요부품에 대한 방사선영향에 대하여 다룬다. 평가대상 부품으로는 중요도가 높은 것들 중에서 선택하였는데, AC 서보모터, 포텐쇼미터, 열전대, 가속도계, CCD 카메라를 그 대상으로 하였다. AC 서보모터의 경우 ACP 핫셀 내 조작기에 여러개가 사용되고 있고, 공정장치의 일부에 사용되고 있다. 포텐쇼미터는 조작기 관절의 절대 각도를 측정하기 위해 사용된다. 열전대는 금속전환장치 등의 반응기 온도 측정을 위해 사용된다. 가속도계는 탈피복시 발생하는 이상을 사전에 감지하기 위한 용도로 탈피복장치에 부착되어 있고, CCD 카메라는 조작기와 함께 공정 휴지기간에 영상 In-situ 이상감시를 하기 위한 용도로 사용된다. 다양한 방사선 중 감마선은 전기, 전자 및 로봇 부품에 가장 치명적이라고 알려져 있으므로 본 연구에서는 Co-60선원을 사용하는 감마조사시설을 이용해 방사선 영향을 평가하였다. 방사선조사결과 CCD 카메라를 제외한 다른 부품들은 방사선에 매우 강인한 특성을 보였다. 누적조사선량에 대한 각 대상 부품의 고유한 특성변화 데이터를 얻었고, 대상 부품의 성능을 보장할 수 있는 기준인 손상분기점에 대한 평가 자료를 얻을 수 있었다

• 제어로봇시스템학회논문지
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• 제5권7호
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• pp.862-867
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• 1999

In general, the realization of high performance brushless permanent magnet motors which are widely used in servo drive is focused on the linear control for ripple-free torque. This is also the main problem that should be solved in all AC motors including induction motor to achieve high performance control, and recent papers deal with this problem. In this paper, the novel optimal excitation scheme of brushless permanent magnet motor producing loss-minimized ripple-free torque based on the d-q-0 reference frame is presented including 3 phase unbalanced condition. The optimized phase current waveforms that are obtained by the proposed method can be a reference values and the motor winding currents are forced to track it by delta modulation technique. As a results, it can be shown that the proposed work can minimize the torque ripple by the optimal excitation current for brushless permanent magnet motor with any arbitrary phase back EMF waveform. Simulation and experimental results prove the validity and practical applications of the proposed control scheme.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.422-428
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• 2002

In this study, actuator, sensor, guide, power transmission element and control method are considered for ultra-precision positioning apparatus. Through previous process, single plane X-Y stage with ultra-precision positioning is manufactured. Global stage for the purpose of materialization with robust system, is combined by using AC servo motor and ball screw and rolling guide. And ultra-precision positioning system is developed by micro stage with elastic hinge type and piezo element. global servo and micro servo for the purpose of materialization positioning accuracy with nm(nanometer) are controlled simultaneously by using incremental encoder and laser interferometer as displacement measurement sensor. Through previous process, ultra-precision positioning system (100mm stroke and ${\pm}$ 10nm positioning accuracy) with single plane X-Y stage are materialized.

• 한국공작기계학회논문집
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• 제11권5호
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• pp.65-72
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• 2002

In this study, actuator, sensor, guide, power transmission element and control method are considered for ultra-precision positioning apparatus. Through previous process, single plane X-Y stage with ultra-precision positioning is manufactured. Global stage for the purpose of materialization with robust system, is combined by using AC servo motor and ball screw and rolling guide. And ultra-precision positioning system is developed by micro stage with elastic hinge type and piezo element. global servo and micro servo for the purpose of materialization positioning accuracy with nm(nanometer) are controlled simultaneously by using incremental encoder and laser interferometer as displacement measurement sensor. Through previous process, ultra-precision positioning system(100mm stroke and $\pm$ l0nm positioning accuracy) with single plane X-Y stage are materialized.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.46.6-46
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• 2001

A servo gun welding system having a AC servo motor and a PC control system is presented for the improvement of quality control in the spot welding. The spot welding process is composed of the press stage, the weld stage, and the hold stage. The changes of gun press forces according to three stages in the spot welding process are controlled and measured through the load cell in order to know the influence on the welding quality. The relation between the measured force changes according to three stages and welding qualities is also implemented on the multilayer perceptrons, one of supervised learning method of neural network, which are powerful for realization of complex mapping characteristics. The estimated results and ...

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.274-277
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• 1996

Vector controlled PMAC(Permanent Magnet AC) motor, with rare-earth permanent magnet, are suitable for servo system demanding fast speed response. However, abrupt acceleration and deceleration control for fast response requires big instantaneous input power. So general PI control of PMAC motors can't be applied for limited power supply system like airplane or portable equipment because of input power fluctuation. Proposed technique to restrain instantaneous input power use variable power limit depends on airgap flux power. Stability check for proposed system is done.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.232-235
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• 2001

This paper presents a circuit of the quasi-resonant DC link to achieve soft-switching three phase inverter using intelligent IGBT power module. The soft-switching operation in this circuit is confirmed simulation and experimental results. Its conductive noise is measured for electrical AC motor drive as compared with that of the conventional hard switching inverter.