• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.453-457
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• 2001

One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric and thermal errors of the machine tools. In this study, the compensation device is manufactured in order to compensate thermal error of machine tools under the real-time. This paper models of the thermal errors for error analysis and develops on-the-machine measurement system by which the volumetric error are measured and compensated. The thermal error is modeled by means of angularity errors of a column and thermal drift error of the spindle unit which are measured by the touch probe unit with a star type styluses, a designed spherical ball artifact, and five gap sensors. In order to compensate thermal characteristics under several operating conditions, experiments performed with five gap sensors and manufactured compensation device on the horizontal machining center.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.417-422
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• 2002

One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric errors, thermally-induced errors, and the deterioration of the machine tools. Geometric and thermal errors of machine tools should be measured and compensated to manufacture high quality products. In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. In this study, the compensation device and temperature-based algorithm have been implemented on the machining center in order to compensate thermal error of machine tools under the real-time. The thermal errors are predicted using the neural network and multi-regression modeling methods. In order to compensate thermal characteristics under several operating conditions, experiments performed with five gap sensors and manufactured compensation device on the horizontal machining center.

• 항공우주시스템공학회지
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• 제10권1호
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• pp.86-94
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• 2016

In this paper, position control of focal plane compensation device using piezoelectric actuator is conducted. The forcal plane compensation device installed on earth observation satellite camera compensates micro-vibration from reaction wheels. In this study, four experimental models of the open-loop compensation device are derived using MATLAB system identification toolbox in the input range of 0~50Hz. Subsequently, the PID controller for each model is designed and the performance test of each controller is conducted through MATLAB/Simulink. According to frequency response analysis of the closed-loop compensation device system, the PID controller designed for 38~50Hz input range has enough tracking performance for the whole 0~50Hz input range. The maximum output error is about $1{\mu}m$ for the input range. The simulation results has been verified by the experimental method.

• 전자공학회논문지
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• 제54권8호
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• pp.115-122
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• 2017

본 논문에서는 슬라이닥을 이용하는 새로운 역률보상시스템을 제안한다. 제안하는 역률보상시스템은 슬라이닥의 출력전압을 커패시터에 인가하여 역률을 보상하는 구조이다. 기존의 커패시터 뱅크 방법을 이용하는 역률보상시스템은 선택 가능한 커패시터 용량이 한정되어 있어 부하 상황에 따라 역률 보상 오차가 발생하지만, 제안 시스템은 커패시터 인가 전압을 슬라이닥을 이용하여 세밀하게 변화시킬 수 있어 변화하는 부하를 추종하여 오차 없이 역률을 100%까지 보상할 수 있다. 기존 시스템과 제안 시스템을 비교하여 제시하고, 제안 시스템의 역률 보상 성능이 우수함을 모의실험과 실험을 통해 확인한다. 제안 시스템을 수용가에 설치할 경우 역률 개선을 통한 전기료 감소, 선로손실 감소, 부하 용량 증대 효과가 기대된다. 특히 발전 사업가측에서는 역률 보상 성능의 향상으로 송전 여유 용량 확보와 발전량 절감이 가능하다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.1095-1096
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• 2008

By adding height compensation to the usual 3 points skew adjustment device, an improved functional skew adjustment device is implemented in this paper. The proposed skew adjustment device is for traverse which will be adapted to BD and HD player system requiring more accuracy. and It can adjust not only R/T skew but also height. The system is composed of personal computer, control box, kinematic mechanism device and bar-code reader device. Application programs are implemented by visual basic.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.37-38
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• 2009

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.214-219
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• 2001

One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric errors, thermally-induced errors, and the deterioration of the machine tools. Geometric and thermal errors of machine tools should be measured and compensated to manufacture high quality products. In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. In this study, the compensation device and temperature-based algorithm have been presented in order to compensate thermal error of machine tools under the real-time. The thermal error is modeled by means of angularity errors of a column and thermal drift error of the spindle unit which are measured by the touch probe unit with a star type styluses, a designed spherical ball artifact, and five gap sensors. In order to compensate thermal characteristics under several operating conditions, experiments performed with five gap sensors and manufactured compensation device on the horizontal machining center.

• 한국항공우주학회지
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• 제43권8호
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• pp.757-764
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• 2015

본 논문에서는 소형 지구관측 위성의 광학카메라에 들어가는 미소진동을 보상하기 위한 초점면부 보정장치 시스템의 실험적 모델링을 수행하였다. 미소진동 외란을 보상하는 초점면부 보정장치의 구동기로 PZT 압전작동기를 적용하였다. 압전작동기는 히스테리시스 고유 특성을 갖게 되므로 보정장치 시스템의 정확한 수학적 모델링을 얻는데 어려움이 있다. 따라서 본 연구에서는 보정장치 시스템을 2차 선형시스템으로 가정하고 MATLAB의 시스템 식별 툴박스(System Identification Toolbox)를 이용하여 실험적으로 모델링을 수행하였다. 외란의 주파수 범위인 0~50Hz에서 응답 오차 10%를 만족하기 위해 단일 선형 모델로는 불가능하며 총 4개의 선형 모델이 필요하다. 각각의 모델은 0~50Hz 입력범위를 4개의 구간으로 나눈 영역에서 실제 동역학을 잘 표현 하고 있다. 미소진동 외란의 보상은 입력주파수에 따라 모델 스위칭 기법을 적용한 초점면부 보정장치 제어를 통해 이루어진다.

• International Journal of Precision Engineering and Manufacturing
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• 제8권2호
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• pp.3-8
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• 2007

A machining system that generates accurate relative motions between the tool and workpiece is required to realize ultra precise machining or measurements. Accuracy improvements for each element of the machine are also required. This paper proposes a machining system that uses a compensation device for the six-degree-of-freedom (6-DOF) motion error between the tool and workpiece. The compensation device eliminates elastic and thermal errors of the joints and links due to temperature fluctuations and external forces. A hexapod parallel kinematics mechanism installed between the tool spindle and surface plate is passively actuated by a conventional machine. Then the parallel mechanism measures the 6-DOF motions. We describe the conception and fundamentals of the system and test a passively extensible strut with a compensation device for the joint errors.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.365-366
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• 2006