• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.363-364
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.183-183
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• 2003

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1095-1096
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• 2010

• Journal of the Korean Society for Precision Engineering
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• v.11 no.6
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• pp.117-126
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• 1994

This paper describes an application step of a $R^{-{\theta}}$ method which measures circular movements in machining centers. The detection of composite errors of circular movements and a high precision cutting method in machining centers were investigated by the analysis of data measured by $R^{\theta }$method which can detect the rotating angle and is applicable to variable measuring radius. When the error by squareness error and unbalance of position-loop-gain were mixed, the detection method of each error was proposed. Although the errors by squarenss error and backlash compensation were mixed, the errors by squareness error be detected. If the errors by unbalance of position-loop-gain and backlash compensation were mixed, the errors by unbalance of position-loop-gain could not detected. A high precision cutting mehod, which uses the NC program compensated by using feed-back data from error measured by the $R^{\theta }$method, was proposed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.162-166
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• 1996

This paper presents a position control of ultra-precision machine tool post using piezoelectric material. A stack-type piezoelectric actuator Is employed in a hinge-type tool holder. An assumed linear transfer function of the practical nonlinear plant is established through the comparison of transfer functions and step responses in the experiments and the simulations. Several types of feedforward/feedback controllers are designed via computer simulations using the assumed linear transfer function. The position tracking control experiments are undertaken to show the control efficiency of each controller.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.493-498
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• 1993

This paper proposes a high precision measurement technique to obtain the height of gage block. The proposed technique is consisted of two steps : In the first step, laser position transducer and electric micrometer are adopted to obtain a coarse value of the height of gage block, and then, second, heterodyne laser interferometry is adopted to acquire the precision value. The experiment results show that accuract in the order of a few nanometer is achieved for the gage blacks of as high as a few millimeter.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1073-1078
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• 2008

This paper is mainly concerned with the characteristics of precision stop on the automatic operating for the train car. Recently, the automatic operation of train car and the PSD establishment inside the subway are magnified. Consequently, the importance and necessity of characteristic of train car precision position stop are augmented. It researches the characteristic of precision position stop when the train car is operated with automatically and plans the safe operation of train car and the method of maintenance which is rational.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1380-1383
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• 2004

The scanning type XY stage is frequently used these days as precision positioning system in equipment for semiconductor or display element. It is requested higher velocity and more precise accuracy for higher productivity and measuring performance. The position accuracy of general stage is primarily affected by the geometric errors caused by parasitic motion of stage, misalignments such as perpendicular error, and thermal expansion of structure. In the case of scanning type stage, H type frame is usually used as base stage which is driven by two actuators such as linear motor. In the point view of scanning process, the stage is used in moving motion. Therefore, dynamic variation is added as significant position error source with other parasitic motion error. Because the scanning axis is driven by two actuators with two position detectors, 2 dimensional position errors have different characteristic compared to general tacked type XY stage. In this study 2D position error of scanning stage is analyzed by 1D heterodyne interferometer calibrator, which can measure 1D linear position error, straightness error, yaw error and pitch error, and perpendicular error. The 2D position error is evaluated by diagonal measurement (ISO230-6). The yaw error and perpendicular error are compensated on the base stage of scanning axis. And, the horizontal straightness error is compensated by cross axis compensation. And, dynamic motion error in scanning motion is analyzed.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1216-1219
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• 2003

The position control is very important in semiconductor manufacturing devices, precision machining tools, precision measuring instruments, etc. The accuracy of measurement for the distance in these devices affect on the performance of the whole devices. Therefore, in those precision instruments, a sensing device that can measure the distance of movement with high-precision resolution is required. In this paper, a novel hybrid (digital and analog) type encoder is proposed. It is shown that from several experiments, a high-resolution angular position measurement device can be designed with a low cost incremental encoder and a DSP controller.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.4
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• pp.190-196
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• 2001

The naval vessel must moves rolling, pitching, yawing by wave when it runs in ocean. Some narrow beam antenna needed position compensation by stabilizer or gimbal for best performance. This paper presents the precision position control for heavy weight(130kg) in roll and pitch direction. Generally it's called for gimbal. This gimbal uses P-I controller, and it's driven by linear actuator and servo motor. This gimbal gets ship's gyro signal and synchro, which have the absolute angle value. Some other similar equipments are driven by huge hydraulic power, but this gimbal is driven by small servo motor. This control loop gets the following procedure repeatedly; reading ship gyro and gimbal synchro, calculating compensated error and control output, driving motor and actuator The performance of gimbal system was satisfied.