• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.90-90
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• 2003

• Journal of Power System Engineering
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• v.13 no.4
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• pp.18-23
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• 2009

구면무단변속기(SS-CVT)는 구조가 간단하여 변속기구의 부피와 무게를 기존의 변속기구에 비하여 줄일 수 있으며, 별도의 클러치 없이 출력축의 정회전, 역회전 그리고 중립상태 등을 구현할 수 있다. 본 연구에서는 이러한 구면무단변속기의 기구적 특징과 변속메카니즘을 이용하여 직류모터와 가솔린엔진을 장착한 병렬형 하이브리드차량의 동력전달계를 제안하고자 한다. 이를 위하여 먼저 구면무단변속기의 작동원리에 대해 설명하고 전용 실험장치를 제작하여 무단변속성능을 검증하였다. 또한 직류모터를 보조 동력원으로 사용하는 병렬형 하이브리드차량 동력전달계의 설계를 위해 연결기어비와 구면무단변속기의 변속비를 차량주행성능에 맞추어 설정하였으며, 이를 차량가속성능의 수치 시뮬레이션을 통하여 분석하였다. 시뮬레이션 결과를 바탕으로 구면무단변속기의 하이브리드차량 동력전달계의 적용가능성을 검증하였으며, 연구결과로 선정된 구성요소의 설계파라미터를 이용하여 시작차량을 제작하였다.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.734-739
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• 2001

In this paper, we develop a six-axes machining center tool(MCT) and CAD/CAM system. The MCT consists of two mechanical parts, i.e., a X-Y-Z Cartesian coordinate typed MCT and a parallel-typed tilting table. Kinematics and singularity are accomplished to design the parallel-typed tilting table, and CAD/CAM system is developed for the six-axes MCT, which requires the commands of position as well as orientation for machining of complex shape. The CAD/CAM system has a tool path generator, a NC code generator and a graphic simulator. This paper designs the parallel-typed tilting table to meet the desired specification and presents the results of tool path, NC code and graphic simulation.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.8 s.197
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• pp.50-57
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• 2007

In this paper, two types of novel planar Translational Parallel Manipulators (TPMs) by using parallelogram mechanism are conceived. One is made up of two Pa-P (Parallelogram-Prismatic) legs connecting the base to the moving platform. The other consists of two P-Pa legs, which is the kinematic inversion of the former. Since connecting links in a parallelogram mechanism are subject to only tensile/compressive load and all the heavy actuators are mounted at the base, the proposed manipulators can be applied for planar positioning/assembly tasks requiring high stiffness and high speed. The position, velocity, and statics are analyzed, and the design methodology using prescribed workspace and velocity transmission capability is presented. Finally, two types of prototype manipulators have been developed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.11 s.242
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• pp.1509-1517
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• 2005

This paper presents the two degree-of-freedom(DOF) planar parallel mechanism called 2R$\underline{P}$R-RP manipulator, whose degree-of freedom is dependent on a passive constraining leg connecting the base and the platform. First, the kinematic analysis of the mechanism is performed analytically: the inverse and forward kinematic problems are solved in the closed font the practical workspace is systematically derived, and all of the singular configurations are examined. Then, in order to determine the geometric parameters and the operating limits of the actuators, the optimization of the mechanism is performed considering its dexterity and stiffness. Finally, the kinematic performances of the optimized mechanism are evaluated through comparing to the 5-bar parallel manipulator.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.12 s.255
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• pp.1564-1572
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• 2006

This paper presents the kinematics and workspace optimization of the two different 2-DOF (Degrees-of-Freedom) planar parallel mechanisms: one (called 2-RPR mechanism) with translational actuators and the other (called 2-RRR mechanism) with rotational ones. First of all, the inverse kinematics and Jacobian matrix of each mechanism are derived analytically. Then, the workspace including the output-space and the joint-space is systematically analyzed in order to determine the geometric parameters and the operating range of the actuators. .Finally, the kinematic optimization of the mechanisms is performed with regards to their dexterity, stiffness and space utilization. It is expected that the optimization results can be effectively used as a basic material for the applications of the presented mechanisms to more industrial fields.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2396-2398
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• 2003

세 개의 체인으로 구성된 병렬형 3 자유도 기구는 특이점을 지님으로 인하여 햅틱기구로 활용시 불특정한 힘반영으로 인해 제한요소가 발생한다. 본 논문은 여유구동을 활용함으로써 특이점을 해소하고, 힘반영의 크기를 증가시킴으로써 햅틱기구의 성능을 향상시키는 것을 목적으로 한다. 또한 여유구동 모터를 베이스에 부착함으로써 관성력을 최소화 시키고, 와이어와 기어비를 활용하여 부드럽고 큰 힘반영 능력을 가능케 했으며, 시뮬레이션을 통해 힘반영 성능을 확인하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.672-675
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• 2000

There are many sources of errors in the parallel device. This study investigates the effect of a clearance error at a U-joint on the position and orientation errors of the platform of a new parallel device, cubic parallel manipulator. In this study, the limits of errors can be estimated for given conditions.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.789-794
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• 2000

This study proposes an error analysis for a cubic parallel device. There are many sources of errors in the device. An error analysis is presented based on an error model formed from the relation between the universal joint error of the cubic parallel manipulator and the end effector accuracy. The analysis shows that the method can be used in evaluating the accuracy of a parallel device.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.565-566
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• 2009