• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.735-738
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• 2008

A 6 D.O.F Stewart platform type parallel robot has been developed as a simulator to test the surveillance robot stabilization control. Since the surveillance robot is installed on the unmanned ground vehicle (UGV), it is required to have a stabilization control system to compensate the disturbance from the UGV. PID control scheme has been applied to the parallel robot to generate controlled motion following the input motion.

• 대한기계학회논문집A
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• 제28권5호
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• pp.495-502
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• 2004

In this paper, kinematic structure of parallel manipulator having 6-DOF is determined to follow the specific trajectory represented by several curves expressed by the parametric variable functions. In addition, the parallel manipulator is designed to have a high dexterity by considering a kinematic isotropy which can stabilize the motion of the moving platform in the restricted workspace.

• 한국운동역학회지
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• 제14권2호
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• pp.15-26
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• 2004

The purpose of this study was to investigate the kinematic variables of peters motion in parallel bars. The subjects were 3 male national gymnasts. For this study, kinematic data were collected using video camera. Coordinate data were low-pass filtered using a fourth-order Butterworth with cutoff frequency of 6Hz. Each valuables analyzed was used to compare kinematic features between the subjects. The conclusions were as follows; 1. For a stable regrasp motion, the subjects appeared to increase horizontal and vertical displacement during the DS phase because it induce a vertical elastic of body and reaction of bar for the US phase. 2. For a stable hand standing motion of the regrasp, the subjects appeared to maintain the fast vertical and horizontal velocity during the DS phase, but in contrary during the US and Air phase the vertical and horizontal velocity appeared to do decrease. 3. When the arm lean angle and the trunk lean angle maintain a big angle during the DS phase, the subjects appeared to do a stable performance to release in a high position.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.361-362
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• 2011

• 대한기계학회논문집A
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• 제33권9호
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• pp.982-989
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• 2009

Parallel Kinematic Mechanism (PKM) is a device to perform the various motion in three-dimensional space and it calls for six degree of freedom. For example, Parallel Kinematic Mechanism is applied to machine tools, medical equipments, MEMS, virtual reality devices and flight motion simulators. Recently, many companies have tried to develop new Parallel Kinematic Mechanism in order to improve the cycle time and the precisional tolerance. Parallel Kinematic Mechanism uses general universal joint and spherical joint, but such joints have accumulated tolerance problems. Therefore, it causes position control problem and dramatically life time reduction. This paper focused on the rolling element to improve sliding precision in new sliding ball joint development. Before the final design and production, it was confirmed that new sliding ball joint held a higher load and a good geometrical structure. FEM analysis showed a favorable agreement with tensile and compressive testing results by universal testing machine. In conclusions, a new sliding ball joint has been developed to solve a problem of accumulated tolerance and verified using tensile and compressive testing as well as FEM analysis.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.671-672
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• 2006

• 한국항공우주학회지
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• 제33권2호
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• pp.1-10
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• 2005

비정상 유동의 모사를 위한 병렬화된 비정렬 중첩격자기법을 개발하였다. 비정렬 격자계에서 효율적이고 강건하게 쓰일 수 있는 탐색방법과 병렬경계에서 유동적으로 변하는 데이터의 수를 처리할 수 있는 자료구조를 제안하였다. 격자계간의 정보전달을 위한 삽간경계면을 정의하였고, 공간상의 이차정확도를 유지하기 위한 삽간방법 및 물체내부에 위치하는 삽간점에 대한 처리방법을 제안하였다. 개발된 해석코드의 검증을 위해 Eglin/Pylon 형상에서 분리되는 스토어의 궤적을 해석하여 실험치와 비교하였고, 다 물체간의 상대운동이 있는 비정상유동의 적용을 위해 세 개의 스토어 분리에 대한 해석을 수행하였다.

• 한국정밀공학회지
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• 제29권4호
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• pp.426-432
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• 2012

In this study, kinematic analysis of forward kinematic, inverse kinematic and jacobian for 6-bar parallel robot was analyzed. In order to analyze the maximum workspace of 6-bar parallel robot, maximum revolution range of active joint was calculated. Also, to analyze forward dynamics and inverse dynamics of 6-bar parallel robot, recurdyn and simmechanics was utilized. Using a PI controller and Feedforward controller make an experiment with square motion of end_effector. The reference value of active joint and trace of end_effector were compared with actual experimental value.

• 한국산학기술학회논문지
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• 제12권1호
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• pp.74-79
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• 2011

정렬 시스템(Alignment System)은 다축의 스테이지를 이용하여 신속하게 물체를 정렬오차 범위 내로 위치결정시키는 역할을 한다. 본 연구에서는 병렬구조로 설계하여 두께가 얇고 높은 정밀도와 더불어 강성이 높은 XY${\theta}$ 정렬 스테이지를 개발하였다. 개발된 박형 병렬구조 XY${\theta}$정렬 스테이지는 직각도, 반복정밀도, 진직도 등의 3가지 측정항목에 대해 초정밀급을 달성하였으며 반복정밀도는 $1{\mu}m$미만이다. 비전시스템 및 정렬알고리즘을 활용한 정렬성능 평가에서는 정렬오차 ${\pm}6.25{\mu}m$를 달성하였다.

• 제어로봇시스템학회논문지
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• 제15권5호
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• pp.543-547
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• 2009

This paper describes the design, simulation, development, and experiment of a six degree-of-freedom micropositioning parallel manipulator. A movable stage was supported with six links, each of which extends with a dc-servo micropositioning actuator. In case of parallel manipulator, while the solution of the inverse kinematics is easily found by the vectors of the links which are composed of the joint coordinates in base and platform, but forward kinematic is not easily solved because of the nonlinearity and complexity of the parallel manipulator's kinematic output equation with the multi-solutions. The movable range of the prototype was ${\pm}25mm$ in the x- and y-directions and ${\pm}12.5mm$ in the z-direction. The minimum incremental motion of the prototype was $1{\mu}m$ in the x- and y-directions and $0.5{\mu}m$ in the z-direction. The repeatability of the prototype was ${\pm}2{\mu}m$ in the x- and y-directions and ${\pm}1{\mu}m$ in the z-direction. The motion performance was also evaluated by not only the computer simulation of CAD model but also the experiment using a capacitive sensor system.