• 제목/요약/키워드: Magneto-rheological Fluid

검색결과 133건 처리시간 0.029초

미세동작제어를 위한 자기유변유체 구동기의 동적 특성 (Dynamic Characteristics of Magneto-rheological Fluid Actuator for Micro-motion Control)

  • 김평화;한철희;칼루반 수레쉬;박춘용;신철수;최승복
    • 한국소음진동공학회논문집
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    • 제26권5호
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    • pp.511-517
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    • 2016
  • This paper presents dynamic characteristics of a new actuator using magneto-rheological(MR) fluid between two electrode type coils. The concept of the actuator is to strengthen the force due to the magnetic field produced by the electrode-coil for MR fluid. The amount and direction of current input to the electrode-coils decide the characteristics of contraction-mode and extension-mode. For achieving the required actuating displacement and actuating force, the yield stress of the MR fluid between two electrode-coils is precisely changed by the input current. In this work, the MR fluid is operated in squeeze mode. The experimental results shown in this paper depict that it can be applied in the micro-level displacement and vibration control system.

자기유변유체를 이용한 회전 각속력 제어 (Control of Rotational Angular Speed using Magneto-rheological Fluid)

  • 신성철;정재성;김정훈;이종원
    • 유변학
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    • 제11권2호
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    • pp.67-72
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    • 1999
  • 본 연구에서는 가해지는 자기장에 따라 항복응력이 변하는 자기유변유체를 이용한 제동 장치를 개발하였다. 현재 선진국을 중심으로 활발히 연구되어지는 자기유변유체는, 유체에 가해지는 자기장의 변화에 따라 유체의 항복응력이 변하는데, 이러한 성질을 이용하여 제동력의 정확한 제어가 가능하다. 본 연구에서는 개발된 제동 장치를 이용하여, 외부에서 회전체에 가해지는 토크가 변동할 경우에 회전체의 회전 속력를 일정하게 유지시키는 기능을 구현하였다. 회전체의 회전속력을 측정하여, 비례-적분 피드백 제어를 사용하여 구현하였다. 우선, 실험과 시뮬레이션 결과의 비교를 통해 개발된 제동 장치의 매개변수값을 구하였고, 이 값들을 이용하여 비례-적분 피드백 제어 시뮬레이션 결과를 예측하였다. 또한 초기 각속력이 있는 자유낙하실험, 수동 크랭킹 실험들을 수행하여, 개발된 장치를 통하여 회전체의 회전속력을 일정하게 유지할 수 있음을 확인하였다. 이러한 속력 제한 기능은 개발된 제동 장치의 응용의 한 예로서, 회전체의 적절한 물리량을 측정한 후. 적절한 피드백 제어를 가하면, 얼마든지 원하는 다른 기능을 구현해 낼 수 있다.

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MR 현가장치를 장착한 승용 차량의 진동제어 (Vibration Control of a Passenger Vehicle Featuring MR Suspension Units)

  • 이환수;최승복;이순규
    • 소음진동
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    • 제11권1호
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    • pp.41-48
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    • 2001
  • This paper presents vibration control performance of a passenger vehicle featuring magneto-rheological (MR) suspension units. As a first step, a cylindrical shock absorber is designed and manufactured on the basis of Bingham Property of a commercially available MR fluid. After verifying that the damping force of the shock absorber can be controlled by the intensity of magnetic field(or input current), it is applied to a full-car model. An optimal controller is then formulated to effectively suppress unwanted vibration of the vehicle system. The control performances are evaluated via hardware-in-the-loop simulation(HILS), and presented in both time and frequency domains.

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지반 기진력을 받는 구조물의 진동제어를 위한 자기유변 감쇠기의 실험적 연구 (An Experimental Study on a Magneto-Rheological Fluid Damper for Structural Control Subject to Base Excitation)

  • 김병현;정종안;문석준
    • 한국소음진동공학회논문집
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    • 제14권8호
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    • pp.767-773
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    • 2004
  • Semi-active control systems have attracted a great deal of attention in recent years, because they offer the adaptability of active devices without requiring large Power sources. One of the most Promising semi-active devices proposed for structural control is magneto-rheological fluid dampers (MR damper). In this paper, an MR damper having the capacity of about 1 ton was designed and fabricated. and series of tests were performed to grasp the fundamental Performance characteristics of it. It was also applied to a 6-story steel structure under random excitation and 3-different seismic excitations for the confirmation of its validity on structural vibration absorption. Through this study, the techniques and know-hows for MR damper production were acquired.

MR 브레이크 고출력화 설계에 관한 연구 (A Study on Design for High-torque MR(Magnetorheological) Brake)

  • 박중호;서미영;이후승;함영복;윤소남;서응수
    • 유공압시스템학회:학술대회논문집
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    • 유공압시스템학회 2010년도 춘계학술대회
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    • pp.105-108
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    • 2010
  • In this study, a MR(Magneto-rheological) brake to obtain high torque-to-size ratio instead of conventional powder brake is presented for high-tension control of converting machinery such as coater, slitter and so on. First, to obtain the higher performance than conventional powder brake, a MR brake with a modified rotor shape is newly designed and analyzed by using electromagnetic field analysis. Second, a prototype of the MR brake is fabricated with the optimized structural parameters and an experimental apparatus is constructed. Finally, basic characteristics between current and torque are experimentally investigated.

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Surface Tension of Magneto-Rheological Fluids

  • Rahimi, Shai;Weihs, Daniel
    • Journal of Magnetics
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    • 제21권2호
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    • pp.261-265
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    • 2016
  • Surface tension is a major factor in the thermodynamics as well as fluid properties of Magneto-Rheological Fluids (MRF). We measured the surface tension of an MRF using two different methods. A wettability characterization based on contact angles measurements for the fluid interacting with two different surfaces was conducted. A hydrocarbon based commercial MRF with more than 80% solid weight, placed on quartz and poly-tetra-fluoroethylene (PTFE) surfaces was used. We measured the fluids' surface tension value by means of contact angles measurements and by the falling drop method.

전자기장 해석을 이용한 자기점성 유체 클러치 코일 작동부 설계 (Design of Magneto-Rheological Clutch Coil Operation Unit using Electro Magnetic Field Analysis)

  • 송준한;최득환;전종균;권영철;이태행
    • 한국자동차공학회논문집
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    • 제17권3호
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    • pp.22-28
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    • 2009
  • Recently, there has been an active study about smart fluid to control the vibration, in which MR fluid is evaluated as most efficient because it can generate different bonding forces based on the intensity of the external magnetic fields. This paper attempts to find a mechanism that, under limited conditions during a clutch production that uses such dynamic characteristic, defects the maximum intensity of electromagnetism. Using the finite element analysis program, we predicted a change within the bonding force of the MR fluid occurring inside the clutch when it is subjected to an increased electric current. In addition, we analyzed the change in the magnetic intensity when the coil comprising the coil control center is switched to multiple lines from the standard single line, to find a mechanism that can maximize the effect. Based on this analysis, we developed the clutch and tested its function, hoping to widen future MR fluid's range of application.

MR 밸브의 전자기적 설계와 성능평가 (Electromagnetic Design and Performance Evaluation of an MR Valve)

  • 김기한;남윤주;박명관
    • 대한기계학회논문집A
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    • 제32권3호
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    • pp.240-249
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    • 2008
  • This paper presents an electromagnetic design method for magneto-rheological (MR) valves. Since the apparent viscosity of MR fluids is adjusted by applying magnetic fields, the MR valves can control high-level fluid power without any mechanical moving parts. In order to improve the performances of the MR valve, it is important that the magnetic field is effectively supplied to the MR fluid. For the purpose, the magnetic circuit composed with the yoke for forming magnetic flux path, the electromagnetic coil and the MR fluid should be well designed. In order to improve the static characteristic of the MR valve, the length of the magnetic flux path is decreased by removing the unnecessary bulk of the yoke. Also, in order to improve its dynamic and hysteretic characteristics, the magnetic reluctance of the magnetic circuit should be increased by minimizing the cross-sectional area of the yoke through which the magnetic flux passes. After two MR valves, one is a conventional type valve and the other is the proposed one, are designed and fabricated, their performances are evaluated experimentally.

ER유체를 이용한 이방성 스퀴즈필름 댐퍼의 응답특성에 관한 연구 (A Modeling of a Variable-damping Mount Using Magneto-Rheological Fluid)

  • 안영공;양보석;삼하신
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 추계학술대회논문집
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    • pp.256-261
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    • 2000
  • Electro-Rheological(ER) fluid is applied to a controllable squeeze film damper(SFD) for stabilizing a flexible rotor system. ER fluid is a class of functional fluid whose yield stress varies according to the applied electric field strength, which is observed as viscosity variation of the fluid. In applying ER fluid to a SFD, a pair of rings of the damper can be used as electrodes. When the electrodes are divided into a horizontal pair and a vertical one, the SFD can produce damping force in each direction independently. A prototype of the directionally controllable SFD was constructed and its performance was experimentally and numerically investigated in the present work.

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