• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.131-134
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• 2001

The three-dimensional precision measurement technology for industry product of middle and/or large scale has been developed. Theodolite measurement system which is one of the technology is widely used in aerospace industry. This paper describes measurement method and results for spacecraft structure test model by using the measurement system. And structural stability for STM is desribed through the comparison between design values and measured values.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.7
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• pp.99-104
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• 2003

A precision displacement measurement system of 3-DOF micro motions is proposed in this paper. The measurement system is composed of two diode lasers, two quadratic PSDs, two beam splitters and a sphere whose surface is highly reflective. In this measurement system, the sphere reflector is mounted on the platform of positioning devices whose 3-DOF translational motions are to be measured, and the sensitive areas of two PSDs are oriented toward the center point of the sphere reflector. Each laser beam emitted from two diode laser sources is reflected at the surface of sphere and arrives at two PSDs. Each PSD serves as a 2-dimensional sensor, providing the information on the 3-dimensional position of the sphere. In this paper, we model the relationship between the outputs of two PSDs and 3-DOF translational motions of the sphere mounted on the object. Based on a deduced measurement model, we perform measurement simulation and evaluate the performance of the proposed measurement system: linearity, sensitivity, and measurement error. The simulation results show that the proposed measurement system can be valid means of precision displacement measurement of 3-dimensional micro motions.

• Journal of the Korean Society for Precision Engineering
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• v.3 no.1
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• pp.60-68
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• 1986

Measurement of surface roughness has been done by two dimensional method until now. In recent, three dimensuional method is introduced for the precise measurement of surface roughness. But the study about stylus type three dimensional measurement method is a little. Therefore, in this study, arbitrary machined surface is selected and same part is measured by two dimensional and three dimensional method. The result is that the ratio of tow dimensional to three dimensional value is 0.9-1.1 in Ra. But two dimensional measurement method is underestimated because the ratio is 0.5-0.9 in Rz, Rmax. And it is suitable that the number of measuring line is 100 and y pitch is 5 um by three dimensional surface roughness measuring method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.100-100
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• 2003

• Journal of the Korean Society for Precision Engineering
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• v.17 no.1
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• pp.129-137
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• 2000

In this paper, a new method of noncontact measurement has been developed for a 3 dimensional topography in semiconductor wafer, implementing a new optical probe based on the precision defocus measurement. The developed technique consists of the new optical probe, precision stages, and the measurement/control system. The basic principle of the technique is to use the reflected slit beam from the specimen surface, and to measure the deviation of the specimen surface. The defocusing distance can be measured by the reflected slit beam, where the defocused image is measured by the proposed optical probe, giving very high resolution. The distance measuring formula has been proposed for the developed probe, using the laws of geometric optics. The precision calibration technique has been applied, giving about 10 nanometer resolution and 72 nanometer of four sigma uncertainty. In order to quantitize the micro pattern in the specimen surface, some efficient analysis algorithms have been developed to analyse the 3D topography pattern and some parameters of the surface. The developed system has been successfully applied to measure the wafer surface, demonstrating the line scanning feature and excellent 3 dimensional measurement capability.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.3-9
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• 2004

The machining parts must be produced within the specification of drawing and those will be able to meet function and efficiency. At that time. it is necessary not only precision machine or machining technique but also the measurement technique is very important. So. the improvement of precise measurement technique is to be joined together at once with improvement of product technique. Finally. he quality and value of the parts are decided by precision measurement. This paper aims to study on he measurement uncertainty when the machined parts are inspected with 3-dimensional coordinate measuring machine. The objectives are to remove an error of measurement and to improve quality and productivity of the mass products.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.2
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• pp.55-61
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• 2005

The machining Parts must be Produced within the specification of drawing and those will be able to meet faction and efficiency. At that time, it is very important not only precision machine and machining technique but also the measurement technique. So, the improvement of measurement technique is to be joined together at once with improvement of machining technique. Finally, the quality and value of the parts are decided by precision measurement. This paper aims to study on the measurement uncertainty when the machined parts are inspected with 3-dimensional coordinate measuring machine. The objectives remove an error of measurement and remove a quality of mass products.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.113-121
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• 1999

It is necessary to calibrate measurement systems to enhance its measurement accuracy. The visual sensing system that is presented in our previous work has to be calibrated, too. It is a multiple mirror system for three-dimensional measurement, which is composed of a camera and a series of mirrors. It is important to calibrate the positions and orientations of the mirrors relative to the camera because they have direct influence on the relationship between the image plane and the task space. This paper presents the calibration method for the visual sensing system. To confirm the measurement performance of the implemented system. its measurement accuracy in measuring the locations in three-dimensional space is investigated. A series of experiments for measuring the locations of the circle-shaped marks are performed. Experimental results show that the sensing system can be effectively used for three-dimensional measurement.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.263-264
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.537-538
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• 2009