• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.355-356
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• 2008

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.443-444
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• 2010

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.554-560
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• 2020

In the manufacturing process of flat panel displays, a high-precision planar motion stage is used to position a specimen. Stages of this type typically use frictionless linear motors and air bearings, and laser interferometers. Real-time dynamic correction of the yaw motion error is very important because the inevitable yaw motion error of the stage means a change in the specimen orientation. Gantry control is generally used to compensate for yaw motion errors. Flexure units that allow rotational motion are applied to the stage to apply this method to a stage using an air-bearing guide. This paper proposes a method to improve the constant speed motion performance of a H-type XY stage equipped with air bearing and flexure units. When applying the gantry control to the stage, including the flexure units, the cause of the mutual ripple generated from the linear motors is analyzed, and adaptive learning control is proposed to compensate for the mutual ripple. A simulation was performed to verify the proposed method. The speed ripple was reduced to approximately the 22 % level. The ripple reduction was verified by simulating the stage state where yaw motion error occurs.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1193-1197
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• 2008

Bridge is Most from stay of Gantry structures part. In compliance with oneself weight of the bridge deflecting, this occurs drops the location precision of the work tool. Also accelerative at the time of gives a serious load to Y axial motors which transfer the bridge damages. The motor with high-speed transfer of location control which is accurate makes disrupt. The malleability of the bridge to maintain consequently and necessary to minimize a weight. This paper the structural FEM interpretations of the stone and the aluminum alloy with the material by which will be used in the bridge and static deflected and a candle precise plane X-Y stage optimal design with character the interpretation result.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.219-223
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• 2006

This paper presents a gantry type 3-axes positioning system, which is useful to test control algorithms for coordinate measuring machines and industrial cranes. The dynamic characteristics of the system have been investigated through a series of finite element analysis and experiments. In order to minimize the residual vibration during movement, this paper implements input shaping algorithms for the system with the information from the dynamic analysis. The results show that the dynamic performance of the system can be significantly improved by the dynamic analysis and implementation of input shaping

• Journal of the Korean Society of Industry Convergence
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• v.21 no.6
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• pp.273-284
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• 2018

3D printing technology in the construction field is currently being developed and commercialized actively in foreign countries, but the development of material and equipment is underway as an initial research stage in Korea. It is necessary to implement commercialization through the introduction of 3D printing technology in the construction field as soon as possible in Korea, but there is no guideline for suitable equipment and materials in Korea at present. Therefore, in order to help prepare for commercialization, it is necessary to provide data such as equipment size and materials suitable for commercialization at the initial stage. This study investigates the types, specifications, and applications of equipment that are being used overseas to provide the equipment type and material cost required in the initial stage of commercialization in Korea. Using the surveyed data, it was possible to calculate the advantages and disadvantages of the equipment type and specification, and the cost of materials used. As a result of the analysis, Gantry type is suitable for the domestic commercialization, and the standard of the output area is $100m^2$ and the extrusion amount of $250m^3/sec$ is proposed, and the material cost of the commercial product is 20thousand won. The suggestions in this study will help to plan the construction of products and equipments to commercialize 3D printing technology in construction field in the future.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.9
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• pp.909-915
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• 2009

This work is to develop a vision system for high precision alignment between upper and lower plates required at the imprinting process of the large LCD flat panel. We compose a gantry-stage that has highly repeated accuracy for high precision alignment and achieves analysis about thermal transformations of stage itself. Position error in the stage is corrected by feedback control from the analysis. This system can confirm alignment mark of upper and lower plates by using two cameras at a time for the alignment of two plates. Pattern matching that uses geometric feature is proposed to consider the recognition problem for alignment mark of two plates. It is algorithm to correct central point and angle for the alignment from the recognized mark of upper and lower plates based on the special characteristics. At the alignment process, revision for error position is performed through Look and Move techniques.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.471-474
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• 2001

Recently, due to demands of faster speed and extra features for the chip mounters, there has been ever-demanding needs for the basic technology. Until four or five years ago, chip mounters placing 0.3sec/chip were considered to be in the high speed category, but since then it has become a borderline for categorizing high speed machines capable of placing 0.1sec/chip. In this study, in order to analyze the vibration of head generated by the dynamic behavior of x-frame, FEM model is composed and modal analysis is performed to identify the dynamic characteristics of the structure. Those results are compared with the modal test in order to verify the model. In this paper, Several other factors, such as definition of dynamic accuracy, static accuracy and tolerance of the axis settling range, that might affect the dynamic behavior the head are discussed.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.136-137
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• 2002

We have been researching upgrade version of a stereotactic whole body frame, used for evaluating daily setup accuracy of the patient positioning during fractionated extra-cranial stereotactic radiotherapy. Currently, we are focusing on the development of a new stereotactic whole body frame, and then will handle organ movement produced by breathing at the next stage. MeV-Green is chosen for the best immobilizer possible and the epoxy board is for the frame with the dimension of 110 em in length, 50 cm in width in order to maximize transmission rate of the beam from lateral or posterior direction and to fit CT and PET scanners with an aperture of 55 cm at least. The key point of an upgraded stereotactic whole body frame will be set on the collision-free rotation of the gantry with the frame, and the development of the checking structure for the daily patient repositioning regarding internal target.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.2
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• pp.129-138
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• 2012

In this study, three types of large scale multi-tasking machine tools together with core technologies involved have been developed and introduced; a multi-tasking machine tool for large scale marine engine crankshafts, a multi-tasking vertical lathe for windmill parts, and a large scale 5-axis machine tool of gantry type. Several special purpose devices has been necessarily developed for the purpose of handling and machining big and heavy workpieces accurately, such as PTD (Pin Turning Device) with revolving ring spindle for machining eccentric crankshaft pins, hydrostatic rotary table and steady rest for supporting and resting heavy workpieces, and 2-axis automatic swiveling head for high-quality free surface machining. Core technologies have been also developed and adopted on their detail design stage; 1) structural design optimization with FEM structural analysis, 2) theoretical hydrostatic analysis for the PTD and rotary table bearings, 3) box-in-box type cross-rail and octagonal ram design to secure machine rigidity and accuracy, 4) constant spindle rpm control against gravitational torque due to unbalanced workpiece.