• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.399-404
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• 2002

Improvement of measuring accuracy is an essential part of quality control manufacturing process. The OMM is less than the CMM in measure accuracy but the OMM system is more efficient, easier to use than other measurement system. About 40~70% of the machine tool errors are induced by the thermal errors. Therefore, a key requirement for improving the measuring accuracy is to reduce the geometric and thermal errors. Thermal errors are measured by a ball bar system and predicted by the thermal error modeling. Furthermore, using the pre-defined thermal error map approach compensates the geometric accuracy of the OMM. Appropriate experiments are performed using ball-bar system, temperature measuring devices and touch-type probe. Compensated results are compared with those obtained using CMM to verify the proposed methods.

• KIEAE Journal
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• v.10 no.4
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• pp.3-8
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• 2010

Recently, various daylight evaluation methods for visual environment have been developed; simulation analysis methods, numerical calculation, and data monitoring methods. However, it is impossible for simulation analysis to make real scenes and visualize real images exactly. Also, a numerical calculation is considered as an out of date and time-consuming mean. Therefore, for acquisition of accurate results, many studies often use the monitoring data methods. Especially, most studies regarding discomfort glare are evaluated by measuring the physical quantity of luminance through traditional measuring Minolta Luminance meters as an instrument. But, this method has a difficulty in measuring several points at the same time because of the limitation of spaces and time when mapping. So, this study focused on the potential usefulness of High Dynamic Range photography technique as a luminance mapping tool. In order to evaluate the accuracy of proposed programs such as webHDR, Photomatix and PHOTOLUX, this paper has conducted an experiment by using Canon EOS 5D and NICON Coolpix8400 digital camera.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.1002-1005
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• 2000

The goal of this study is to develop a linear DC motor with high thrust, speed and stiffness for machine tool. In the first phase of this study, We has made a pilot model and measuring system. Using the measuring system, We could finished the performance test of the pilot model, which continuous thrust is 1, 391N. Experimental values agree with the theoretical results well. In a certain sense, We are expecting the realization of linear motor with continuous thrust of 6, 000 to 7, 000N next time.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.251-257
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• 1998

The distribution of fatigue crack growth rate is subjected to the measuring interval and calculated method of growth rate. In this paper, in order to establish the method of determining the distribution of fatigue crack growth rate, which ignores those influences, a series of fatigue crack growth experiments and measuring intervals of crack length calculated reasonable are presented. The main conclusions obtained are summarized as follows: 1) As a result of the ΔP constant test and ΔK constant test, it is thought that an approximate measuring interval of 0.3~0.7mm is reasonable, which allows for few errors and is little subjected to the calculated method of crack growth rate.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.1
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• pp.106-112
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• 2008

In this paper, It does the profile measurement of the cam of diesel engine SOHC of the actual object. It uses the measurement of run-out method. This method is that the surface of the object is measured by the sensor when the object rotate, and calculated and displayed by the computer the signal which acquired by sensor. When we acquire the signals, we have two error because of motion and contacting between cam and probe. In this paper, we compensate the motion error while simply liner equation. And we have a solution that we change the figure of probe when we have a contacting error. We compared the data measuring on developed automatic cam profile measuring system with the data measured on CMM.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.260-265
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• 1994

Efforts have been devoted to developing rapid and accurate methods for measuring the errors of machine tools. The method os measurement and calibration of machine tool errors should be general and efficient. The objective of this study is to show in detail the full sequence from the measurement of errors factors to the verification of the positioning accuracy after compensation for the volumetric error. In this paper, we described the steps in measuring the volumetric error parameters, a general error model composed of error parameters, temperature, and the desired position. The validity of the error calibration methods proposed in this paper was tested using a vertical 3-axis CNC machine with a laser interferometer and a ball bar.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.3-7
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• 2000

The authors have realized reconstruction of 3D shape using contacting method with pins and TCP/IP communication. In this paper, the working principal of the mechanism is proposed and tested. A special sensor system is designed as 148 matrix form to measure 3D shape. When contact occurs between pin and the plate of the sensor matrix, the position information of pins is sent to computer and raised height data of the pin is obtained by counter which accumlates encoder signal. So, all datum which contain 3-dimensional coordinate, is transferred using TCP/IP communication. Finally, 3D shape is reconstructured by Web browser of remote computer. The measuring result shows that the proposed mechanism is reliable and promising as a remote measuring device through Internet.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.3
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• pp.20-27
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• 2003

Compensation of probe radius is required for accurate measurement in metal working industry. Compensation involves correctly measuring data on the surface in the amount of radius of the touch probe with a Coordinate Measuring Machine (CMM). Mechanical parts with free-formed curves and surfaces are complex enough so that accurate measurement and compensation are indispensable. This paper presents necessary algorithms involved in the compensation of the probe radius for free-formed curves and surfaces. Application of pillar curve is the focus for the compensation.

• KIEAE Journal
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• v.4 no.4
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• pp.45-52
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• 2004

Simulation of daylighting by computer program is a method to avoid unnecessary efforts in manufacture of its testing models, to reduce its measuring tolerances and be able to provide variations of various weather conditions as well. Many simulation programs on daylighting have been released freely or commercialized for selling, however, a demonstration of their availability and validity as a tool for evaluating daylighting performance is required since each one has its own characteristics. The objectives of this study lie in suggesting an application method of evaluation tools and demonstration of limits and characteristics so as to more easily determine the daylightingperformance in the very initial stages of planning for an arbitrary office space in which windows with daylight access are built. We produced scale model of the general light inducing type side lighting with lightshelfand ceiling, and the luminance (at 78 measuring points) and illuminance (at 84 measuring points) were measured in a clear sky. And a comparison of the measured values and the calculated values from a computer simulation using the Lightscape program was performed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.424-428
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• 2005

This paper shows a non-contact optical method to inspect micron scale parts which will be manufactured in micro-factory system. This inspection system should have some characteristics like a small size, flexibility, and high measuring speed. In the viewpoint of measuring capabilities, it also has resolution under micron scale with measuring range over millimeter scale. Two methods will be presented in this paper, one is Moire and the other is white-light scanning interferometry. Also some experimental results will be presented to show the possibilities of the proposed inspection system.