• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.15-18
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• 2000

We developed a human-sized BWR(biped walking robot) driven by a new actuator based on the ball screw which has high strength and high gear ratio. The robot overcomes the limit of the driving torque of conventional BWRs. Each leg of the robot is composed of three pitch joints and one roll joint. In all, a 10 degree-of-freedom robot with two balancing joints was developed. The BWR was developed to walk autonomously such that it is actuated by small torque motors and is boarded with DC battery and controllers. In the performance test, the BWR performed nice motions of sitting-up and sitting-down. Through the test, we could find capability of high performance in biped-walking.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.105.6-105
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• 2002

Contents 1We developed a new type of lower part of the human-sized BWR (biped walking robot) driven by a new actuator based on the ball screw which has high strength and high gear ratio. Each leg of the robot is composed of three pitch Joints and one roll joint. In all, a 8 degree-of-freedom robot was developed. A new type of actuator for the robot is proposed, which is composed of four bar link mechanism driven by the ball screw. The BWR was designed to walk autonomously by adapting small DC motors for the robot actuators and has an embeded controller system including host computer, batteries and motor drivers. In the performance test, we had basic stable walking data so far, but we f...

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.805-809
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• 2003

We developed a human-sized BWR(biped walking robot) named KUBIR1 driven by a new actuator based on the ball screw which has high strength and high gear ratio. KUBIR1 was developed to walk autonomously such that it is actuated by small torque motors and is boarded with DC battery and controllers. To utilize the information on the human walking motion and to analyze the walking mode of robot, a motion capture system was developed. The system is composed of the mechanical and electronic devices to obtain the joint angle data. By using the obtained data, a 3-D graphic interface was developed based on the OpenGL tool. Through the graphic interface, the control input of KUBIR1 is performed.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.2
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• pp.102-109
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• 1996

Effects of frictional laws on finite element solutions in metal forming were investigated in this paper. A rigid-viscoplastic finite element formulation was given with emphasis on the frictional laws. The Coulomb friction and the constant shear friction laws were compared through finite element analyses of compression of rings and cylinders with different aspect ratios, ring-gear forging, multi-stage cold extrusion and hot strip rolling under the isothermal condition. It has been shown that two laws may yield quite different results when the aspect ratio of a process and the fractional contact region are large.

• International journal of advanced smart convergence
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• v.9 no.1
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• pp.10-18
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• 2020

In the case of a belt-pulley type CVT that transmits a driving force by using a variable pulley and a metal belt, slippage occurs due to transmission of power by using a belt, which results in a decrease in efficiency. Therefore, in this study, the rails were machined on the plate surface of the pulley to reduce the friction and slip between the belt and the pulley while applying the characteristics of the CVT. As the plate is rotated by the shape of the rail, a centrifugal belt pulley type continuously variable transmission system which shifts while varying the radius of rotation of the belt that transmits power is studied. Accordingly, the structure of the pulley was designed and the centrifugal belt pulley type continuously variable transmission was Manufactured. In addition, to verify the suitability of the manufactured transmission, the power transmission efficiency was monitored by establishing an interface with the controller. The structural analysis of the plate proved the suitability of the centrifugal belt pulley type continuously variable transmission.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.6
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• pp.484-491
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• 2002

We developed a new type of human-sized BWR (biped walking robot) driven by a new actuator based on the ball screw which has high strength and high gear ratio. Each leg of the robot is composed of three pitch joints and one roll joint. In all, a 10 degree-of-freedom robot with two balancing joints was developed. A new type of actuator for the robot is proposed, which is composed of four bar link mechanism driven by the ball screw. The robot overcomes the limit of the driving torque of conventional BWRs. The BWR was designed to walk autonomously by adapting small DC motors for the robot actuators and has a space to board DC battery and controllers. In the performance test, the BWR performed sitting-up and down motion, and walking motion. Through the test, we found the possibility of a high performance biped-walking.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.583-586
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• 2000

The conventional actuators with the speed reducer had weakness in supporting the weight of the body and leg itself. To overcome this, a new four bar link mechanism actuated by the ball screw was proposed. The four bar mechanism has higher strength and gear ratio than the conventional actuator to actutate the leg of the biped robot. One leg was designed to have ankle, thigh, and hip joints. The kinematics and dynamics of one leg with four bar link mechanism was analyzed using Euler-Lagrange approach. The dynamics of one leg was expressed in the ball strew frame.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.880-881
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• 2015

최근 풍력발전의 산업이 성장함에 따라 풍력 발전기의 부속품에 대한 연구도 활발해지고 있다. 이에 본 논문에서는 풍력 발전기의 기계적 증속기의 문제점을 개선한 비접촉식 자기 기어를 제안하고 기어비에 따른 기어의 특성을 분석하였다. 각 모델들의 전체 크기 및 자석 사용량은 동일하게 고정하였으며 기어비에 따른 극수 및 회전수만을 조절하여 도출된 결과값을 바탕으로 풍력발전기용 증속기 설계 시 기어비 결정에 대한 지표를 제시하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.10
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• pp.2501-2513
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• 1994

In this paper, a compact, light-weight, universal, spherical 3-degree-of-freedom, parallel-structured manual controller with high reflecting-force capability is implemented. First, the position analysis, kinematic modeling and analysis, force reflecting transformation, and applied force control schemes for a parallel structured 3 degree-of-freedom spherical system have been described. Then, a brief description of the system integration, its actual implementation hardware, and its preliminary analysis results are presented. The implemented parallel 3 degree-of-freedom spherical module is equipped with high gear-ratio reducers, and the friction due to the reducers is minimized by employing a force control algorithm, which results in a "power steering" effect for enhanced smoothness and transparency (for compactness and reduced weight).d weight).

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.10
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• pp.572-581
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• 2000

When the manipulator consisting of high ratio gear reducers at its joints is used as the slave manipulator in teleoperated systems, its dynamic characteristics is much slower than that of the master manipulator and it is likely to encounter the saturation in the input magnitude. The control input saturation generates an windup phenomenon that the system stability and position tracking performance of the slave manipulator are to be deteriorated. This paper proposes an force reflecting control scheme and its design method which compensates the control input saturation with absolute stability. The proposed scheme is shown to give a stable force reflection while compensating for control input saturation effectively.