• 대한기계학회논문집A
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• 제29권11호
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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.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.286-291
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• 2002

We present the analysis and design of a new six degree-of-freedom parallel mechanism, Eclipse-II, which can be used as a basis for general motion simulators. This mechanism allows x, y and z-axis translations and a, b and c-axis rotations. Most significantly, it presents the advantage of enabling continuous 360 degrees spinning of the platform. We first describe the computational procedures for the forward and in inverse kinematics of the Eclipse-II. Next, the complete singularity analysis is presented for the two cases of end-effector and actuator singularities. Two additional actuators are added to the original mechanism to eliminate both types of singularities with in the workspace. Some practical aspects of the prototype development are introduced.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.743-748
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• 2004

In this paper, an analysis on a new robot manipulator developed for the side buffing of the shoes is presented. The robot is composed of five D.O.F. An Analysis on the forward and inverse kinematics was performed. The hardware system including electric wirings, control system, and related system was developed. Also, The teleoperating communication system was developed to shake with other related system Computer programs to track the bonding line of shoes were developed. An user-friendly graphic program was developed using C $^{++}$ language for the users.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.213-216
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• 1996

This paper studies a class of in-parallel manipulators with special geometry where the forward displacement analysis problem can be solved easier than the fully parallel manipulators. Three horizontal links of this mechanism provide 3DOFs(Degrees of Freedom), which are one degree of orientational freedom and two degrees of translatory freedom. Three vertical links of this mechanism provide 3DOFs, which are two degrees of orientational freedom and one degree of translatory freedom. The main advantages of this manipulator, compared with the Stewart platform type, are the capability to produce pure rotation and to predict the motion of the moving platform easily. Since this manipulator has simple kinematic characteristics compared with the Stewart platform, controlling in real-time is possible due to less computational burden. The purpose of this investigation is to develope an analytical method and systematic method to analyze the basic kinematics of the manipulator. The basic kinematic equations of the manipulator are derived and simulation is carried out to show the performance of the mechanism.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2154-2159
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• 2005

This paper presents the kinematic analysis of two robots, an exoskeleton type master robot and a human like slave robot with two arms. Two robots are designed and built to be equivalent as motion following robots. The operator wears the exoskeleton robot to generate motions, then the slave robot is required to follow after the motion of the master robot. However, different kinematic configuration yields position mismatches of the end-effectors. To synchronize motions of two robots, kinematic analysis of mapping is analyzed. The forward and inverse kinematics have been simulated and the corresponding experiments are also conducted to confirm the proposed mapping analysis.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1482-1487
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• 2003

This paper presents a new family of 4-DoF parallel mechanism with two platforms. The new mechanism is composed of front and rear platforms, and three limbs. Two limbs with 6dof joint (P-P-S-P) are attached to the each platform and are perpendicular to baseplate, while the middle limb with 4-Dof joints (R-R-R-P or R-R-P-P) is attached to the revolute joint that connect front and rear platform. The two-DoF-driving mechanism at the middle limb with two base-fixed prismatic actuators can generate the heaving and roll motions or two translational motions. Therefore, Therefore, the new 4-Dof parallel mechanism (1T-3R) can generate pitch motions at each platforms, roll, and heaving motions, while another type of new 4-Dof parallel mechanism (2T-2R) can generate pitch motions at each platforms, x and z translational motions. For 1T-3R mechanism, kinematic analyses including inverse, forward kinematics, and Jacobian are performed.

• 로봇학회논문지
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• 제17권1호
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• pp.58-67
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• 2022

In this paper, we propose an approach resolving inaccuracy of the low-cost redundant manipulator workspace with low encoder and low stiffness. When the manipulators are manufactured with low-cost encoders and low-cost links, the robots can run into workspace inaccuracy issues. Furthermore, trajectory generation based on conventional forward/inverse kinematics without taking into account inaccuracy issues will introduce the risk of end-effector fluctuations. Hence, we propose an optimization for the trajectory generation method based on the DDPG (Deep Deterministic Policy Gradient) algorithm for the low-cost redundant manipulators reaching the target position in Euclidean space. We designed the DDPG algorithm minimizing the distance along with the jacobian condition number. The training environment is selected with an error rate of randomly generated joint spaces in a simulator that implemented real-world physics, the test environment is a real robotic experiment and demonstrated our approach.

• 한국정밀공학회지
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• 제14권1호
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• pp.78-83
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• 1997

The paper presents the experimental analysis of a Stewart platform-based force-torque senor. The closed-form solution of forward kinematics of the Stewart platform is derived approximately by way of a linearization technique, and the solution is used in the force analysis of the force-torque sensor. An exper- mental studies show that the proposed method including gravity compensation algorithm is valid for Stew- art platform-based force-torque sensors. The performance of the developed force-torque sensor is evaluated in view of accuracy and linearity in measurements.

• 한국운동역학회지
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• 제18권1호
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• pp.147-158
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• 2008

본 연구의 목적은 우수 고등학교 테니스 선수 7명을 대상으로 테니스 서브 스탠스 유형(pinpoint stance, platform stance)에 따른 서비스 동작의 운동학적인 분석을 통하여 빠른 서브를 구사할 수 있도록 지도할 기초자료를 제공하는데 있다. Pinpoint Stance는 백스윙국면에서 뒷발을 앞발방향으로 이동하기 때문에 신체중심(COM)과 라켓의 많은 움직임으로 인해 소요시간이 Platform Stance 보다 0.04초 길게 소요되었다. 발을 이동하면서 골반부위를 앞으로 이동시켜서 몸을 활처럼 많이 휘게 함으로써 백스윙부터 임팩트까지 파워를 낼 수 있는 구간을 넓혀 COM과 라켓의 속도를 빠르게 하여 서브의 속도를 증가시키는데 기여하는 스탠스임을 알 수 있었다. Platform Stance는 백스윙국면에서 발의 이동이 없기 때문에 COM과 라켓의 작은 움직임으로 인해 소요시간이 Pinpoint Stance 보다 0.04초 짧게 소요되었다. 발의 이동이 없어서 파워를 낼 수 있는 구간을 좁혀 COM과 라켓의 속도가 느리게 나타났지만 중심의 안정감을 높여 서브의 성공률을 높이는데 기여하는 스탠스임을 알 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.126.2-126
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• 2001

This paper, the integration of driving simulator and unmanned vehicle by means of new concept for better performance through a tele-operated system is suggested. But autonomous system is one of the most difficult research topics from the point of view of several constrains on mobility, speed of vehicle and lack of environmental information. In these days, however, many innovations on the vehicle provide the appropriate automatic control in vehicle subsystem for reducing human error. This tendency is toward to the unmanned vehicle or the tele-operated vehicle ultimately. This paper describes the motion system ...