• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.781-782
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• 2011

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1093-1094
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• 2011

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.573-574
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• 2011

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.3
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• pp.96-99
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• 2002

We developed 1:1 resistance ratio measurement system for precision measurement of a series-resistor type dc voltage divider. By using active guard technique and exchange technique, any leakage effects, which are one of the most critical error sources, were successfully removed. The best measurement uncertainty with the developed ratio measurement system was estimated to be approximately $10^{-8}\;for\;10\;k{\Omega}\;and\;100\;k{\Omega}$.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.8
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• pp.62-69
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• 2003

In most shipyards, the measurement of 3-dimensional relative position of pipes should be connected in the block depends on the manual operation. It results a very tedious and inefficient procedure, thus the proper measurement system is needed to improve productivity and accuracy. This paper describes the development of pipe measurement system including system concepts, measuring procedures, system calibration, and its accuracy and productivity. And also, the possibility and things to be improved for application in shipyard are discussed in this paper.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.6
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• pp.607-614
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• 2013

In this study, effect of the sensor gain error is theoretically analyzed and simulated when mixed sequential two-prove method(MTPM) is applied for the precision measurement of straightness error of a linear motion table. According to the theoretical analysis, difference of the gain errors between two displacement sensors increases measurement error dramatically and alignment error of the straightedge is also amplified by the sensor gain difference. On the other hand, if the gain errors of the two sensors are identical, most of error terms are cancelled out and the alignment error doesn't give any influence on the measurement error. Also the measurement error of the straightness error is minimized compared with that of the straightedge's form error owing to close relationship between straightness error and angular motion error of the table in the error terms.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.69-76
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• 2005

The laser interferometer system such as HP5529A is one of the most powerful equipment fur measurement of the straightness error in precision stages. The straightness measurement system, HP5529A is composed of a Wollaston prism and a reflector. In this system, the straightness error is defined as relative lateral motion change between the prism and the reflector and computed from optical path difference of two polarized laser beams between these optics. However, rotating motion of the prism or the reflector used as a moving optic causes unwanted straightness error. In this paper, a compensation method is proposed for removing the unwanted straightness error generated by rotating the moving optic and an experiment is carried out for theoretical verification. The result shows that the unwanted straightness error becomes very large when the reflector is used as the moving optic and the distance between the reflector and the prism is far. Therefore, the prism must be generally used as the moving optic instead of the reflector so as to reduce the measurement error. Nevertheless, the measurement error must be compensated because it's not a negligible error if a rotating angle of the prism is large. In case the reflector must be used as the moving optic, which is unavoidable when the squareness error is measured between two axes, this compensation method can be applied and produces a better result.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.253-255
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• 2010

Needs to study on distance measurement accuracy in aerial and satellite photogrammetry are rapidly increased. However, conventional studies show some confused definitions between measurement accuracy and measurement precision as well as standard deviation(STDEV) and root mean square error(RMSE or RMSD). So, Finite definitions of measurement accuracy and measurement precision as well as STDEV and RMSD are addressed in this paper. Experiment result show using correct definitions improve the distance measurement accuracy in aerial and satellite photogrammetry rapidly, but not the distance measurement accuracy in aerial and satellite photogrammetry.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.7-13
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• 2004

초정밀 공작기계의 기능은 초정밀 운동에 의해 대부분 지배된다. 이러한 운동을 생성하는 고정밀 베어링의 운동정밀도는 이미 나노미터 레벨에 도달하고 있으며, 이러한 운동정밀도를 나노미터 레벨의 정밀도로 측정하는 것(정밀나노계측)이 중요한 과제가 되고 있다. 예를 들어, 초정밀선반 등에 있어서, 공기베어링을 대표로 하는 높은 회전정밀도를 갖는 회전축(주축)이 사용되고 있으며, 따라서 이러한 고정밀 주축의 회전정밀도를 나노미터 레벨의 정밀도로 평가하는 기술은 매우 중요하다. (중략)

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.205-219
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• 1993

제품의 기하학적 칫수 공차는 생산제품의 품질관리에 매우 종요하며, 측정기기의 발달과 함께, 컴퓨터를 이용한 기하하적 공차 해석의 수요와 경향은 늘고 있는 추세이다. 본 논문에서는, ISO의 공차 정의에 기초한 공차들(진직도공차, 편평도공차, 진원도공차, 평행도공차, 직각도공차, 윤곽공차)을 해석할 수 있는 컴퓨터 모듈이 개발되었다. 특히 윤곽공차의 경우 측정프로브의 반경의 효과가 배제되는 알고리즘을 개발하였다. 개발된 컴퓨터 모듈을 실제적인 측정작업에 적용하였으며, 고종도와 고효율성을 보임을 입증하였다.