• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.5 s.122
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• pp.415-426
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• 2007

In a link motion punch press, numerous links are interconnected and each link executes a constrained motion at high speed. As a consequence, dynamic unbalance force and moment are transmitted to the main frame of the press, which results in unwanted vibration. This degrades productivity and precise stamping work of the press. This paper presents an effective method for reducing dynamic unbalance in a link motion punch press based upon kinematic and dynamic analyses. Firstly, the kinematic analysis is carried out in order to understand the fundamental characteristics of the link motion mechanism. Then design variable approach is presented in order to automate the model setup for the mechanism whenever design changes are necessary. To obtain the inertia properties of the links such as mass, mass moment of inertia, and the center of mass, 3-dimensional CAD software was utilized. Dynamic simulations were carried out for various combinations of design changes on some links having significant influences on kinematic and dynamic behavior of the mechanism.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.982-986
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• 2000

Perpendicular guideway mechanism has a different behavior with horizontal guideway mechanism due to the slider weight. So, to decrease its weight effect, counter balances such as weight type and hydraulic cylinder type are used. But it can also make another motion behavior by weight rate of slider and counter balance, its connected position. Therefore, it is necessary to find design parameters and analyze their effect. This paper dealt with the optimal design of perpendicular guideway mechanism. For analysis, the theoretic model as same as real machine tool and sib plate to adjust the clearance was used. Rotational angle and displacement of slider, pressure distribution, friction distribution were calculated. Stick slip, intermittent motion of slider according to friction change was adapted to the perpendicular guideway mechanism.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.5
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• pp.756-768
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• 1997

In order to control a dynamic gait of quadrupedal walking robot, the equations of motion of the whole mechanism are required. In this research, the equations of motion are formulated analytically using Kane's dynamic approach. As a dynamic gait model, a trot gait has been adopted. The degree of freedom of whole mechanism could be reduced to 7 by idealizing the kinematic feature of the trot gait. Using the equations of motion formulated, the results of the redundant-joint torque analysis and the simulation of dynamic walking motion are presented.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.772-777
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• 2000

Cam mechanisms are used commonly in many automatic machinery. Disk cam mechanisms has 4 different types according to the different types of followers. The motion characteristics of the cam mechanisms depend on the shape of the cam and the type of the follower. This paper performs the motion analysis for a disk cam and follower mechanism using a circular arc method and a coordinate transformation method in order to find a contact point of the cam and follower. The velocity is calculated by using the instant velocity concept. Also, the acceleration is determined on using the central difference method. As the results, this paper presents the original curve and the analyzed curve for the motion analysis of the disk cam for an example.

• Advances in Computational Design
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• v.4 no.3
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• pp.197-210
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• 2019

Motion generation of a four-bar linkage is a type of mechanism synthesis that has a wide range of applications such as a pick-and-place operation in manufacturing. In this research, the use of meta-heuristics for motion generation of a four-bar linkage is demonstrated. Three problems of motion generation were posed as a constrained optimization probably using the weighted sum technique to handle two types of tracking errors. A simple penalty function technique was used to deal with design constraints while three meta-heuristics including differential evolution (DE), self-adaptive differential evolution (JADE) and teaching learning based optimization (TLBO) were employed to solve the problems. Comparative results and the effect of the constraint handling technique are illustrated and discussed.

• Journal of Navigation and Port Research
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• v.38 no.2
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• pp.97-103
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• 2014

In these days, the world has been increasing navy forces such as aircraft carriers and high-tech destroyers etc. and the importance of submarines is being emphasized. Therefore, accurate values of the derivatives in equations of motion are required to control motion of the submarines. Hydrodynamic derivatives were measured by the vertical planar motion mechanism(VPMM) model test. VPMM equipment gave pure heave and pitch motion respectively to the submarine model and the forces and moments were acquired by load cells. As a result, the hydrodynamic derivatives of the submarine are provided through the Fourier analysis of the forces and moments in this paper.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.1
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• pp.89-97
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• 2001

In this paper, we present a new two-dof anthropomorphic joint mechanism that enables to mimic the humanlike motion. The proposed mechanism, called Double Active Universal Joint(DAUJ), generates a two-dof swivel motion without rolling by the coupled motion of two independent motor. In addition, we perform basic experiments to confirm the effectiveness of the proposed mechanism and the results are reported.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1922-1927
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• 2005

This paper describes the mechanism of a new biped machine capable of doing human-robot cooperation work. The biped machine, WABIAN-2 is made of two seven degrees of freedom (DOF) legs, a two DOF waist and no DOF trunk. Its leg system consists of two three DOF ankles, two one DOF knees and two three DOF hips to deal with various walk motions. Its height is about 1.2[m], and its weight is 40[kg]. It is designed with large movable range as a human. Also, a knee stretch walk pattern generation for the biped machine to perform natural walk like a human is discussed in this paper. Its leg motion is compensated by using the motion of its waist. Basic knee stretch walk experiments using WABIAN-2 are conducted on the plane, and the validity of its mechanism and walk pattern generator is verified.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.269-272
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• 1987

This paper is concerned on kinematic analysis and simulation of an automatic feeding mechanism subjected by the motion of a curvilinear inverse cam. The main objection is the development of computer-aided design (CAD) program for simulating the motion of the cam-feeding mechanism using computer-graphics. A computer program CACAFS (Computer-Aided Cam and Automatic Feeding System) is independent of computer hardware used. The program is also interactive using a menu-selection technique. As the second part of the paper for the motion simulation of the cam-feeding system, this paper discusses the state-of-art for CAD. The first part of the paper presents the algorithm to simulate the notion of the cam-feeding mechanism.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.12
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• pp.111-116
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• 2019

With the recent acceleration of industrial technologies and active research, wearable robot technologies have been applied to various fields. To study the utility of wearable robots, basic research on kinetic mechanisms of the human body, bio-signal analysis, and system control are essential. In this study, we investigated the basic structure of a wearable system and the operating principles of a driving mechanism. The control system and supporting structure, which comprise the driving mechanism, were designed and manufactured. Motion and load analyses were performed simultaneously for the design of the kinematic drive, and the driving mechanism was constructed by analyzing walking motion. The operating conditions of the cylinder were verified by stride via driving experiments. Further, the accuracy and responsiveness of the system were confirmed by comparison with actual motion, and the system safety was validated by applying loads.