• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2420-2422
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• 2004

In this paper, we developed a miniaturized humanoid having the new joint mechanism. In general, the high torque actuator and the joint mechanism having three coincided axes are important in development of the miniaturized humanoid. By using the swash plate, which is generally used in three axes rotor mechanism, we developed a new three-coincided-axes joint mechanism and a miniaturized humanoid having the joint mechanism at its hip and ankle joints. Since the joint mechanism has a pair of parallel drive motors for each axis, the driving torque of the joint mechanism is very high. Futhermore, thanks to the three-coincided-axes mechanism, the solution of the inverse kinematics is simple and computationally efficient, and the resulting walking behavior of the humanoid becomes natural.

• 한국정밀공학회지
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• 제24권4호
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• pp.109-114
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• 2007

The mobility (degree of freedom) of mechanisms can be regarded as independent coordinate to define its position. This concept is essential for kinematics, and for designing mechanisms in the practical point of view. Gruebler's equation has been applied to estimate the mobility using number of links and joints of a mechanism. In practical case, there are many types of mechanisms, which transfer motion by direct contact between two links. However, no exact kinematic definition has existed for the joint that the contact takes place in a mechanism. In this paper, a new concept of contact joint is defined and modified Gruebler's equation is suggested to calculate mobility of a mechanism with the joint. This concept would be useful in mechanism design because it will be possible to manage many contact mechanisms with kinematic exactness.

• 로봇학회논문지
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• 제14권4호
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• pp.237-244
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• 2019

This paper suggests novel types of joint mechanisms composed of elastic strings and rigid bodies. All of the human hinge joints have the articular capsule and a pair of collateral ligaments. These fibrous tissues make the joint compliant and stable. The proposed mechanism closely imitates the human hinge joint structure by using the concept of tensegrity. The resultant mechanism has several characteristics shown commonly from both the tensegrity structure and the human joint such as compliance, stability, lightweight, and non-contact between rigid bodies. In addition, the role and feature of the human hinge joints vary according to the origins of a pair of collateral ligaments. Likewise, the locations of two strings corresponding to a pair of collateral ligaments produce different function and motion of the proposed mechanism. It would be one of the advantages obtained from the proposed mechanism. How to make a joint mechanism with different features is also suggested in this paper.

• 한국정밀공학회지
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• 제28권11호
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• pp.1272-1278
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• 2011

Mechanisms of the robot system should be developed according to the task. In this study, we propose improving adaptability of the robot mechanism with the modularized joint mechanism. Adaptability is the measure of the system ability to cope with change or uncertainty. Modular type joint has been widely used in development of various robots including reconfigurable robots. To build robotic systems more flexibly and quickly with low costs of manufacturing and maintenance, we have designed a modular type joint with one degree of freedom for general purpose. This module is designed to be compact, light-weight and self-controlled. In this design, we consider the kinematics and dynamics properties of the modular type joint.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.531-534
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• 1996

In this work, we investigate the characteristics of output compliance matrix of a planar 3 degree-of-freedom parallel mechanism when joint compliances are attached to the mechanism redundantly. It is shown by simulation that by attaching redundant joint compliances symmetrically to the mechanism, the translational and rotational compliances can be arbitrarily modulated within some ranges. This property could be effectively used in the control of the compliance characteristics of actively adjustable RCC devices.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 추계학술대회 논문집
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• pp.369-370
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• 2009

• 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 2010년도 춘계학술대회 논문집
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• pp.337-338
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• 2010

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.281-282
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• 2009

• 한국지능시스템학회:학술대회논문집
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• 한국지능시스템학회 2008년도 춘계학술대회 학술발표회 논문집
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• pp.223-226
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• 2008

This paper presents an effectiveness of a four-link mechanism with a tip which has four joints, but only one is an active joint. Even though the degree-of-freedom of the mechanism is one, it can be applied to implement a combined joint motion adequately. So, this paper analyzes its motion for effective robotic applications.