• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.672-676
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• 2004

In this paper, measuring system of 5 DOF motion errors are proposed using two capacitive type sensor, a straight edge and a laser interfoerometer. Yawing error and pitching error are measured using the laser interferometer, and rolling error is measured by the reversal method using a capacitive type sensor. Linear motion errors of horizontal and vertical direction are measured using the sequential two point method. In this case, influence of angular motion errors is compensated using the previously measured angular motion errors. In the horizontal direction, measuring accuracy is within 0.05 $\mu$m and 0.27 arcsec, and in the vertical direction, it is within 0.15 $\mu$m and 0.5 arcsec. From these results, it is confirmed that the proposed measureing system is very effective to the measurement of 5 DOF motion errors in the ultra precision feed tables.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.785-790
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• 2001

Linear motors can drive a linear motion without intermediate gears, screws or crank shafts. Linear motors can successfully replace ball lead screw in machine tools, because they have a high velocity, acceleration and good positioning accuracy. On the other hand, linear motors emit large amounts of heat and have low efficiency. In this paper, heat sources of a synchronous linear motor with high velocity and force are measured and analyzed. To improve the thermal stiffness of the linear motor, an insulation layer with low thermal conductivity is inserted between cooler and machine table. Some effects of the insulation layer are presented.

• 한국정밀공학회지
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• 제19권3호
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• pp.123-130
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• 2002

Linear motors can drive a linear motion without intermediate gears, screws or crank shafts. Linear motors can successfully replace ball lead screw in machine tools because they have a high velocity, acceleration and good positioning accuracy. On the other hand, linear motors emit large amounts of heat and have low efficiency. In this paper, heat sources of a synchronous linear motor with high velocity and force measured and analyzed. To improve the thermal characteristics of the linear motor, an insulation layer with low thermal conductivity is inserted between cooler and machine table. Some effects of the insulation layer are presented.

• 대한기계학회논문집
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• 제12권2호
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• pp.389-396
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• 1988

본 연구에서는 위의 세가지 보간 알고리즘 가운데서 가장 속도의 균일성이 좋은 DDA방식을 채택하였다. 그리고 윤곽제어에서 가공경로는 대개 직선과 원호 구간의 조합으로 구성되어질 수 있기 때문에, 본 연구에서는 직선 및 원호보간만 고려하기로 한다.

• 한국정밀공학회지
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• 제21권7호
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• pp.185-194
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• 2004

In order to analyze the motion errors of the aerostatic stage, it is necessary to consider the influence of the moment variation occurred inside the pads. In this paper, a motion error analysis method utilizing the transfer functions on the reaction force and moment is proposed, and general characteristics of the transfer functions are discussed. Calculated motion errors by the proposed method show good agreement with the ones calculated by Multi fad Method, which is considered the entire table as an analysis object. Also, by the introduction of the transfer function of motion errors, which represent the relationship between the spatial frequency components of the rail form error and motion errors, motional characteristics of the porous aerostatic stage can be generalized. In detail, the influence of the spatial frequencies is analyzed qualitatively, and the patterns of the insensitive frequencies which almost do not affect the linear motion error or angular motion error according to the rail length ratio and the number of the pad are verified. The relationship between the moment variation occurred inside the pads and the motion errors is also verified together.

• International Journal of Precision Engineering and Manufacturing
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• 제5권2호
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• pp.60-67
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• 2004

For improving the motion accuracy of hydrostatic tables, a corrective machining algorithm is proposed in this paper. The algorithm consists of three main processes. The reverse analysis is performed firstly to estimate the rail profile from the measured linear and angular motion error, in the algorithm. For the next step, the corrective machining information is obtained based upon the estimated rail pronto. Finally, the motion errors on the correctively machined rail are analyzed by using the motion error analysis method. These processes are iterated until the analyzed motion errors are satisfactory within the target accuracy. In order to verify the validity of the algorithm theoretically, the motion errors calculated by the estimated rail after the corrective machining process, are compared with those by the true rail which is previously assumed as the initially measured value. The motion errors calculated using the estimated rail show good agreement with the assumed values, and it is shown that the algorithm is effective in acquiring the corrective machining information to improve the accuracy of hydrostatic tables.

• 한국생산제조학회지
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• 제22권6호
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• pp.913-920
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• 2013

This paper presents an applicable basic design that can configure non-contact levitation table for conveying a large sheet of glass. The suggested air levitation table consists of a series of air chambers with porous pads and fans as the conveyor system. The air supply chambers are arrayed to supply an adequately strong upward airflow for supporting the glass. Levitation is controlled by the size and discharge velocity, of the chamber arrays, as well as the glass supporting height. After pre-evaluation of the glass rigidity and the filer functional performance, a one-way fluid structure interface (FSI) analysis is performed for predicting pressure and deflection working of the 8G glass in the transverse and longitudinal directions, respectively. After comparing calculated levels of flatness of the glass, it determines the chamber array for the linear non-contact conveying motion.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 춘계학술대회 논문집
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• pp.272-276
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• 1993

We made to develop CNC Tool Grinding Machine automating the linear motion of X,Y,Z axis of table, and thetilting and rotation of tool holding vice by using Encorder to increase the efficiency of tool grinding for the Conventional Tool Grinding Machine. We did not consider the part of static, dynamic and thermal behavior that must necessary consider when wedesign, because we used existing Conventional Tool Grinding Machine as it is. We investigated simulation to make existing Conventional Tool Grinding Machine like CNC. We also designed it, and we compared the capability of existing Conventional Tool Grinding and CNC Tool Grinding Machine, and we investigated, too.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.182-184
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• 2001

Linear pulse Motor(LPM) are used a field where smooth linear motion is required, and it's position accuracy higher than that of a lead. According to the advantage such as simplicity of mechanical frame, high reliability, precise open_loop operation, low inertia etc LPM is applied largely where it have made motor of this kind more and more attractive in many application areas such as factory automation and high speed positioning. This paper is researched to analyze for thrust force characteristic of hybrid LPM. Both the thrust and normal force are very sensitive to the airgap and tooth pitches of the force and platen. To find the optimal design parameter on the hybrid LPM for the embroidery machine. For the field analysis, the finite element method(FEM) is employed for calculating the force. The reluctance models will be used the magnetic permeance of airgap under static-conditions. The forces between forcer and platen have been calculated using the virtual work mathod.

• 한국운동역학회지
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• 제24권4호
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• pp.317-327
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• 2014

As a single subject study, it was purposed to investigate kinematic differences between Yang Hak Seon vault (i.e., handspring forward and salto forward straight with triple twist, Yang-1 vault hereafter) and Tsukahara $1260^{\circ}$ twist with salto forward straight (Yang-2 vault hereafter) in gymnastics. Yang Hak-Seon (23 years, 160 cm, and 52 kg) voluntarily participated in this study. Motion capture system, consisting of fourteen cameras, were used to measure Yang-2 vault with the sampling rate of 200 Hz. Twenty six reflective markers were placed on major anatomical points of 15 body segments. Successful two trials of Yang-2 vault were collected and analyzed for the comparison. Compared Yang-1 results were based on the previous study of Park and Song (2012). Results indicated superior linear kinematics of Yang-1 vault to those of Yang-2 vault before the touchdown of vault table. However, Yang-2 vault revealed superior angular kinematics to Yang 1 vault showing more trunk twist angle (a triple and a half twist) and its faster angular velocity during the airborne. The Yang 2 vault could has advantage of increasing angular motion than Yang 1 vault as a result of a half turn off the springboard onto the vault table and a sequential touchdown of the hands.