• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.1
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• pp.101-109
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• 1993

Dynamic characteristics of an electro-magnetic clutch transmission system were investigated by using Bondgraph modeling method. Simulation results showed that when the rotor engaged with the armature, the response time of the current, the driver torque, the rotational speed and the relative sliding time between the driver and the driven side decreased, as the gap size between the rotor and the armature decreased and the number of coil turns increased. Also, when the rotor disengaged with the armature, the delay time increased with the decreased gap size and the increased number of coil turns. It was found that the experimental results of the current, the driver torque, the rotational speeds were in good accordance with the theoretical results. The results of this study can be used as basic design materials of the electro-magnetic clutch.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.505-509
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• 2001

When the spindle is rotated for machining the workpiece, the vibration is generated due to the spindle unbalance. This vibration affects surface finish, dimensional accuracy, tool life, and spindle bearings. To compensate this effect of the spindle unbalance, the spindle system using an EME(electro magnetic exciter)is proposed in this paper. In the proposed spindle system, the vibration due to the spindle unbalance is monitored using vibration sensors and is compensated by electromagnetic attractive forces generated in the EME which are excited by anti-direction forces corresponded with the measured unbalance. Firstly, the spindle system using an EME and control system are constructed to compensate the effect of spindle unbalance in this paper. And then the system is modeled by bond graph to analyze the system. Finally, a controller for vibration compensation due to spindle unbalance is designed and is implemented in real experimental system. As a result, experimental results show this proposed spindle system is very effective to compensate the spindle unbalance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.635-640
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• 1996

A thermo-elastic system in the production machine has highly nonlinear dynamic characteristics. In general, the finite element method is utilized for accurate analysis. However, it requires large computing time. Thus, thermo-elastic systems are usuallymodeled as electric and fluid system using lumped para,eter. In this paper. we propose the bondgraph model and transient simulation methodology of thermo-elastic system in consideration of various boundary and joint contact conditions. Consequently, the proposed method ensures a possibility of its on-line compensation about undesirable phenomena by using real time estimate process and electronic cooling device for thermal appropriate behavior. Thermo-elastic model consisting of bush and shaft including contact condition is presented.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.327-330
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• 2005

동적시스템의 공학적 설계는 대부분 구성요소들의 구조적 연결과 요소들의 파라미터들의 결정을 포함하며, 구조와 파라미터 모두 제한이 없는 열려진 특성을 가진다. 본 연구에서는 효율적인 구조/파라미터 탐색을 위한 교대 탐색법을 제안하고 이를 멀티-에너지 도메인 시스템 해석 및 설계에 적합한 본드 그래프를 이용하여 고유값 설계 문제에 적용하였다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.4
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• pp.649-657
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• 1992

Transmission error for a stepping motor-timing belt drive system is investigated experimentally and analytically. From FFT analysis of the experimental results, it is found that the transmission error consists of three periodic errors : (1) error by the stepping motor per one resolution angle theta.$_{m}$, (2) error by the pulley eccentricity per one revolution theta.$_{e}$, and (3) error by the meshing effect between the belt and the pulley teeth per one pitch revoltion theta.$_{p}$. In order to investigate the effects of some design parameters on the transmission error, the dynamic models of the stepping motor-timing belt drive system are derived by Bondgraph. According to the simulation results, as the belt total tension increases, theta.$_{m}$ and theta.$_{e}$ decrease due to the nonlinearity of the belt. In adition, the numerical and experimental results show that theta.$_{m}$ and theta.$_{e}$ of the loaded case are larger than those of the unloaded case. The analytical results are in good accordance with the experimental results.sults.s.sults.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.521-527
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• 2002

This paper presents a dynamic modeling and a robust PID controller design process for the wire bonder head assembly. For the modeling elements, the system is divided into electrical system, magnetic system, and mechanical system. Each system is modeled by using the bond graph method. The PID controller is used for high speed/high accuracy position control of the wire bonder assembly. The Taguchi method is used to evaluate the more robust PID gain combinations than conventional one. This study makes use of an L18 array with three parameters varied on three levels. Computer simulations and experimental results show that the designed PID controller provides more improved signal to noise ratio and reduced sensitivity than the conventional PID controller.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.69-77
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• 1995

This paper presents performance investigation of a continuously variable ER(Electro-Rheological) damper for passenger vehicles. A dynamic model of the damper is formulated by incorporating electric field-dependent Bingham properties of the ER fluid. The Bingham properties are experimentally obtained through Couette type electroviscous measurement with respect to two different particle concentrations. The governing equation of the hydraulic model treating three components of fluid resistances;electrode duct flow, check valve flow and piston gap flow, is achieved via the bond graph method. A prototype ER damper is then designed and manufactured on the basis of parameter analysis. The damping forces of the system are experimentally evaluated by changing the intensity of the electric field, the particle concentration and the electrode gap.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.189-192
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• 2005

공학시스템의 설계 문제는 시스템 구성이 복잡하고, 구조적으로 열려있으며, 전기, 기계, 유압, 열등의 서로 다른 에너지 도메인 구성 요소를 포함한다. 최적의 설계를 위해서는 각 도메인에 대한 통합된 설계 방법과 자동적이고 구조적으로 열린 공간에 대한 효율적인 탐색방법이 요구된다. 본 논문은 도메인에 독립적이며 모델링과 해석에 장점을 가진 본드 그래프 (bond graph)와 대규모 공간 해의 탐색에 접합한 진화 알고리즘의 일종인 유전자 프로그래밍(Genetic Programming)을 결합하여 멀티 도메인 동적시스템에 대한 디자인 해를 자동적으로 생성해주는 설계 방법을 제시하고, 제안된 설계방법의 효용성을 입증하기 위해서 이를 아나로그 필터 설계에 문제에 적용하였다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.96-102
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• 2000

Spinning mechanism is generally used in coasting process on grass plates. Rebounding PR(Photo Resist) which leads to occur inferiority of coating process is caused by vibrational energy of whole coating system. In this study, the sensitivity analysis is performed to analyze and reduce vibrational terms in the spin coating system. The sensitivity analysis is bared on the numerical expression of this system. By the bond graph method. power flow of each system is represented by some basic bond graph elements. Any energy domain system is modeled using the unified elements. The modelled spin coater system is verified with power spectrum data measured by FFT analyzer. As the results of verifying model parameters and sensitivity analysis, principal factors causing vibration phenomenon are mentioned. A study on vibration method in the spin coating system is discussed.

• Journal of the Semiconductor & Display Technology
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• v.1 no.1
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• pp.21-28
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• 2002

This paper presents a dynamic modeling and a robust PID controller design process for the wire bonder head assembly. For modeling elements, the system is divided into electrical part, magnetic part, and mechanical part. Each part is modeled using the bond graph method. The PID controller is used for high speed/high accuracy position control of the wire bonder assembly. The Taguchi method is used to obtain the more robust PID gain combinations than conventional one. This study makes use of an L18 array with three parameters varied on three levels. Results of simulations and experimental show that the designed PID controller provides a improved ratio of signal to noise and a reduced sensitivity improved to the conventional PID controller.