• 대한기계학회논문집A
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• 제25권3호
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• pp.362-368
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• 2001

To design a limiting MCCB (Molded Case Circuit Breaker) mechanism, a dynamic modeling of the mechanism in which the electro-magnetic force effects are incorporated needs to be developed. Conventionally, electro-magnetic effects were considered separately for the design of the mechanism. In this paper, an electro-magnetic force that is induced by limited current is identified and included in the dynamic modeling of the mechanism. Thus, the electro-magnetic which is defined as a external force and the mechanical effects are simultaneously considered for the design of the mechanism which is composed of contactor, spring , link, latch and so on.

• 드라이브 ㆍ 컨트롤
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• 제15권4호
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• pp.55-60
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• 2018

Force-controlled electro-hydrostatic actuators have to exhibit high backdrivability, to quickly compensate for force control errors caused by externally disturbed rod movement. To obtain high backdrivability, the servomotor for driving the hydraulic pump, should rotate exactly to such a revolution to compensate for force control errors, compressing or decompressing cylinder chambers. In this study, we proposed a modified velocity control structure, including a robust internal-loop compensator (RIC)-based velocity controller, for the servomotor to improve backdrivability of a force-controlled EHA. Performance improvement was confirmed experimentally, wherein sinusoidal velocity disturbance was applied to the force-controlled EHA, with constant reference input. Its dynamic force control errors reduced effectively, with the proposed control scheme, compared to test results with a conventional motordriver, for motor velocity control.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.595-602
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• 2013

An air circuit breaker (ACB) with novel double-breaker contact and permanent magnet actuator (PMA) is presented. Three-dimensional (3-D) finite element method (FEM) is employed to compute the electro-dynamic repulsion forces, including the Holm force and Lorentz force, which are acting on the static and movable contacts. The electro-dynamic repulsion forces of different contact pieces are computed, illustrating there is an optimal number of contact pieces for the ACB being studied. The electro-dynamic repulsion force of each contact, which varies from the outer position to the inner position, is also computed. Finally, the contacts of the double-breaker are manufactured according to the analyzed results to validate the simulations.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.109-114
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• 2001

This paper presents field-dependent dynamic characteristics of a shock damper featuring an electro-rheological(ER) damper. A cylindrical type of the shock damper is designed and manufactured on the basis of the field-dependent Bingham model. The damping force is then measured with respect to the piston velocity at various electric fields. The measured damping force is incorporated with the 1DOF shock system to analyze the shock isolation performance.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.710-714
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• 2005

A dynamical analysis and PID control of a compressed gas expulsion system is performed. The purpose of this study is to develop a compressed gas discharging system and to verify the validity of the system. The electro-hydraulic servo valve is modeled as a 3th order transfer function to calculate flow force affecting expulsion valve is significantly considered. The friction force in the expulsion valve is considered as a nonliner model of stribeck effect. The dynamic characteristics of this system is examined by the computer simulation. The position control of the expulsion valve is performed by PID controller.

• 드라이브 ㆍ 컨트롤
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• 제14권4호
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• pp.17-22
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• 2017

In this study, the back-drivability of the single-rod and double-rod type EHAs (Electro-Hydrostatic Actuators) was compared by computer simulation and experiments. The back-drivability of EHAs exhibit non-linear behavior like their force tracking performance. In case of the double-rod type EHA, the back-drivability was mostly influenced by the bulk modulus of oil that changes with the working pressure due to entrapped air. The back-drivability of the single-rod type EHA was directly affected by the operation states of its pilot-operated check valves, while the asymmetrical piston geometry and the non-linear bulk modulus of oil also made the dynamic response in building up the cylinder pressure dependent on the operating conditions.

• 한국항공우주학회지
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• 제45권4호
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• pp.328-341
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• 2017

발사체의 추력벡터제어를 위한 구동장치시스템에서 관성부하를 갖는 전기기계식 위치서보 시스템의 공진 특성과 유연한 기체구조체 지지부의 구조공진이 결합되어 합성공진이 발생한다. 이렇게 발생한 공진은 발사체의 자세제어시스템에 되먹임되어 자세안정성에 영향을 줄 수 있다. 본 논문에서는 발사체의 추력벡터제어를 위한 직구동 방식의 전기기계식 구동장치의 합성공진을 해석하기 위한 모델을 소개하고 합성공진 현상을 저감하여 구동기의 동특성을 개선하는 동적 하중 되먹임 제어기법의 해석 및 시험 결과를 기술하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1210-1214
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• 2008

Electro-pneumatic servo valve is an electro-mechanical device which converts electric signal into pneumatic flow rate or pressure. In order to improve the overall performance of pneumatic servo systems, electro-pneumatic servo valves are required, which have fast dynamic characteristic, no air leakage at null, and can be fabricated at a low-cost. The first objective of this research is to design and fabricate a new electro-pneumatic servo valve which satisfies the above-mentioned requirements. In this paper, we has been modeled as a system consisting of coupled electro-mechanic and mechanical subsystems. The appropriateness of the model has been verified by simulation. The simulation model resolves the valve body motion and the solenoid current at high accuracy. Also, we are calculate the displacement of spool and computed results show winding currents, magnetic actuator force, flux density line, displacement, velocity, back EMF, eddy current etc.

• 전기전자학회논문지
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• 제21권3호
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• pp.174-184
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• 2017

본 논문은 철도 차량용 electro-mechanical brake (EMB)의 클램핑 포스 과도응답 향상을 위한 토크 예측 제어 방법을 제안한다. 일반적으로 철도 차량에는 공압식 제동 시스템이 사용된다. 공압식 제동 시스템은 외부환경 변화에 민감하며, 과도응답 속도가 느리기 때문에 공주시간이 증가한다. 또한, 긴급 제동과 같은 기준 이상의 제동 토크를 인가하는 경우에 제동 효율이 낮은 단점이 있다. 이러한 공압식 제동 시스템의 단점은 철도 차량용 EMB 시스템을 적용하여 극복할 수 있다. 철도 차량용 EMB 시스템은 차량의 축중을 감소시키고, 설계 공간을 확보하기 때문에 연비 증가 및 설계 유연성 확보 등의 장점을 갖는다. 본 논문에서는 철도 차량용 EMB의 클램핑 포스 과도응답 향상을 위한 제어 방법을 제안한다. 제안하는 제어 방법의 타당성은 시뮬레이션을 통해 검증한다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.452-457
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• 2000

This paper presents control response of a semi-active electro-rheological(ER) suspension. After showing dynamic characteristics of the ER damper, 1/4 car model is formulated by incorporating with the time constant of the damping force. $H_{\infty}$ controller compensating mass and time constant uncertainties is then designed in order to suppress vibration level of the suspension. The control responses such as vertical acceleration are presented.