• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1027-1028
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• 2009

• Journal of the Korean Society for Precision Engineering
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• v.18 no.6
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• pp.87-92
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• 2001

An error analysis is very important for a precision machine to estimate its performances. This study proposes a new parallel device, cubic parallel manipulator. Errors of the proposed cubic parallel manipulator include upper and down universal joint errors, due to the directional changes in the forces in the links, and actuation errors. An error analysis is presented based on an error model formed through the relation between the universal joint errors of the cubic parallel manipulator and the end effector accuracy. The analysis shows that the method can be used in predicting the accuracy of other cubic parallel devices.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.211-214
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• 2000

An error analysis is very important for a precision machine tool to estimate its performance. This study proposes a new parallel device, a cubic parallel manipulator. Errors of the proposed cubic parallel manipulator include universal joint errors, errors occurring due to changes in the fore directions in the links, and actuation errors. An error analysis is performed for the manipulator platform moving at uniform velocity. The analysis shows how the position and orientation of the platform influences the directional link forces that change the errors in the manipulator. The analysis shows that the method can be used in predicting the accuracy of parallel devices.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.397-401
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• 1997

An error analysis is very important for a precision machine to estimate its performances. This study deals with error of a new parallel device, cubic parallel manipulator. There are so many error sources in this mechanism. Errors of the cubic parallel device vary depending on the stiffness of the manipulator. The stiffness of each link depends on the directions of the link and actuation force. In this paper, the stiffness of the manipulator is calculated by ARAQUS and the position and orlentation errors are predicted within a given workspace. The analysis shows that the method can be used in predicting the accuracy of other parallel devices and in designing parallel devices.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.2
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• pp.168-175
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• 2011

Contouring accuracy of CNC machine tools is very important for high-speed and high-precision machining. In particular, large contour error may occur during corner tracking. In order to reduce the corner contouring error, acceleration and deceleration control or tool-path planning methods have been suggested. However, they do not directly control the corner contouring error. In the meantime, network servo systems are widely used because of their easiness of building and cost effectiveness. Communication latency between the master controller and servo drives, however, may deteriorate contouring accuracy especially during corner tracking. This paper proposes a control strategy that can accurately calculate and directly control the corner contouring error. A prediction control is combined with the above control to cope with communication latency. The proposed control method is evaluated through computer simulation and experiments. The results show its validity and usefulness.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.1
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• pp.45-52
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• 1996

It is one of the important causes that the precision of the thread grinder decide the machining errors of the ball screw. The approach described in this study demonstrates how the dominant causes of the inaccuracies in thread grinding system can be determined. To evaluate the machining error of thread grinder, rotary encoder is allocated to spindle shaft and master screw for measuring the rotational transfer error between spindle shaft and master screw and the laser measuring system is used for checking the movement error.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.541-542
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.905-909
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• 1997

A geometric error of machine parts is one of the most important factors that affect the accuracy of positioning, generating and measuring for precision machinery. It is known that the thermal deformation of a workpiece during surface grinding is the most important in the geometric error of ground surface. This paper experimentally describes the grinding characteristics of creep-feed grinding. The wheels have 6 slotted pieces in order to compare the grinding temperature with the geometric.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1162-1165
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• 2003

Contouring errors are important especially for high speed and precision machining. Since the contouring errors of a machine tool affect the error of a machined part directly, it is necessary to find the contouring errors by some relevant tests. In this study, contouring errors are obtained by performing circular tests with a grid plate. Various error sources are diagnosed by a least square method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.33-34
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• 2008