• Proceedings of the KSME Conference
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• 2007.05a
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• pp.991-996
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• 2007

Since the performance of the circuit breaker mainly depends on the spring operating mechanism, the analysis of the spring operating mechanism is required. The spring, especially closing spring, stores the deformation energy due to the compression and then accelerates the big loads rapidly in the circuit breaker. To accurately carry out the kinematic and dynamic analysis of the circuit breaker, the precise modeling of the spring behavior is necessary. In this paper, the static stiffness of the spring is captured by using the tester. When the spring is used in the circuit breaker, it is installed horizontally. Therefore, Sine excitation tests are carried out horizontal and vertical direction. Three types of spring models such as a linear spring model, modal spring model, and nodal spring model are suggested and compared with the experimental results.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.117-121
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• 2001

This paper presents a new approach to the calibration of a SCARA robot orientation with a camera modeling that accounts for major sources of camera distortion, namely, radial, decentering, and thin prism distortion. Radial distortion causes an inward or outward displacement of a given image point from its ideal location. Actual optical systems are subject to various degrees of decentering, that is, the optical centers of lens elements are not strictly collinear. Thin prism distortion arises from imperfection in lens design and manufacturing as well as camera assembly. It is our purpose to develop the vision system for the pattern recognition and the automatic test of parts and to apply the line of manufacturing.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.381-385
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• 1996

본 연구에서는 자동화 제조 시스템 (Automatic Manufacturing System :AMS)의 설계및 구현에 있어서 물리적인 검증 (Physical Validation)을 위한 소프트웨어 시스템의 구조를 제안하고 구현하였다. 제안된 소프트웨어 시스템은 설비들과 물류 흐름에 있어서 간섭 검증과 운영 가능성을 검증하는 기능을 제공하며 크게 4개의 모듈로 나누어져 있다. : 1) 기본 형상들을 이용하여 원하는 형상을 정의하는 "Shape Modeling Module", 2) 실제 설비의 Kinematics와 기능을 모델링하는 "Facility Modeling Module", 3) AMS의 물리적인 배치를 구성하는 "Layout Design Module", 4) 모델링된 AMS를 실행시켜 볼 수 있는 "Factory Emulation Module". 이와 같은 소프트웨어 시스템을 구현하기 위해 수행된 주된 연구는 다음과 같다. : 1) AMS를 구성하는 설비들을 모델링하는 방법을 제시, 2) 표준 설비들의 Instancing Parameter 제시, 3) C++과 GL을 이용하여 소프트웨어로의 구현, 4) Flexible Manufacturing System (FMS)에의 응용.lexible Manufacturing System (FMS)에의 응용.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.137-140
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• 1996

This study investigated the length-tension and velocity-force relations of the torso erectors. A myoelectric based approach was used wherein a dynamic biomechanical model incorporating active and passive tissue charactreistics provided music kinematic estimates during controlled sagittal plan extension motions. A double linear optimization formulation from the literatured provided muscle tension estimates. The data supported a linear length-tension relation toward full flexion for both the erector spinae and latissimus muscles. Velocity trends agreed with that predicted by Hill's exponential relation. The results have implications for muscle tension estimation in biomechanical torso modeling, and suggest a possible low back pain injury mechanism.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.456-459
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• 1995

The problem of compliant motion control using a redundant manipulator is addressed in this article. Specifically, a hybrid-control type and impedance-control type controllers are extended to general redundant manipulators based on the kinematically decomposed and geometrically compatible modeling of its joint space. In the case of the hybrid controller, it leads to the linear and decoupled closed-loop dynamics in the three motion spaces, that is the motion-controlled, force-controlled, and the null motion-controlled spaces of the redundant manipulator. When the proposed impedance controller is applied, the decoupled impedance models in three motion spaces are obtained. The superiority of the proposed controllers is verified with the numerical experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.778-783
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• 1994

In operating automated manufacturing system, the long term stability and reliability of NC machine tools become most critical issues. Especially the machining accuracy is dominated by the thermal deformation of machine tools which remains still unsolved and causes troubles in manufacturing operations. Although researches have been carried out on the thermal behavior of a machine tools to minimize or control the thermal deformation of machine tools, the computer models for an analysis of the thermal behacior in machine tools has yet to appear in the open literature. The object of the paper is to present a method of modeling the thermal behavior of a machine tool. The method will make use of finite elements ad be capable of modeling whole machine structures as well as of heat generation processes in the kinematic system components. And temperature distributions and thermal deformations of a CNC lathe are analyzed using the finite element method and are compared with those measured in practice.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.330-331
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• 2014

A mathematical model is suggested for diagnosis on a reciprocating pump. To the end, kinematic, thermodynamic and fluidic analyses are carried out for a simplified reciprocating pump model. The pressure inside the cylinder is expressed as a function of the rotation angle of a crank axle. The mathematical model consists of one cylinder with suction and discharge valves and an accumulator. The effect of valve leakage on the discharge angle is investigated. The discharge angle difference between normal state and leakage state increases with the leakage extent.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.3
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• pp.239-244
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• 2010

This paper is to present map building of mobile robot using RFID (Radio Frequency Identification) technology and ultrasonic sensor. For mobile robot to perform map building, the mobile robot needs its localization and accurate driving in space. In this reason, firstly, kinematic modeling of mobile robot under non-holonomic constrains is introduced. Secondly, based on this modeling, a tracking controller is designed for tracking a given path based on backstepping method using Lyapunov function. The Lyapunov function is also introduced for proving the stability of the designed tracking controller. Thirdly, 2D map building is performed by RFID system, mobile robot system and ultrasonic sensors. The RFID mobile robot system is composed of DC motor, encoder, ultra sonic sensor, digital compass, RFID receiver and RFID antenna. Finally, the path tracking simulation results and map building experimental results are presented to show the effectiveness of the designed controller.

• Korean Journal of Computational Design and Engineering
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• v.6 no.4
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• pp.236-243
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• 2001

A key factor far realizing the internet-based virtual manufacturing system(VMS) and virtual enter-prise(VE) is how to precisely and effectively represent the machine elements and mechanics. In this paper, we present methods to represent the numerically controlled machine tools in the internet environment. The method is composed of: 1) geometrical modeling of the machine tools, 2) kinematic modeling for the movements of the machine tools, and 3) representing the developed model in the internet infrastructure. Based on the models. a web-based virtual machine tools (WVMT) is developed, and it can be accessed at hrrp://wvmt.postech.ac.kr. The WVMT can be used for various purposes: 1) web-based virtual manufacturing system, 2) web-based CAM system, and 3) CNC educational tools for the vocational school through internet.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.6
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• pp.52-60
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• 2005

Ultra-precision positioning systems basically require high natural frequency and sufficient workspace. To cope with this requirement, flexure hinge mechanisms have been developed. However, previous designs are difficult to satisfy the functional requirements of the system due to difficulty in modeling and optimization process applying fur the independent axiomatic design. Therefore, this paper suggests a new design and design procedure based on semi-coupled, axiomatic design. A spatial 3-DOF parallel type micro mechanism is chosen aa an exemplary device. Based on preliminary kinematic analysis and dynamic modeling of the system, an optimum design is conducted. To check the effectiveness of the optimal parameters obtained by theoretical approach, simulation has been performed by FEM.