• Title/Summary/Keyword: magneto rheological damper

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Identification of Dynamic property of MR Fluid (MR 유체의 동특성)

  • Ahn, Young-Kong;Ha, Jong-Yong;Ahn, Kyoung-Kwan;Yang, Bo-Suk;Shiraishi, Toshihiko;Morishita, Shin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.576-579
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    • 2005
  • MR (Magneto Rheological) fluids are well known as a smart fluid and their application researches to control vibration have been conducted by many researchers. However, their dynamic properties have not been identified clearly yet. Therefore, the MR effect is investigated by using a rotational viscometer and a single degree of freedom system with an MR damper. The results obtained from the experimental study show that stiffness and viscous damping coefficients of the system with an MR damper are changed according to the variation of the applied current.

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Design and Control of a Passive Compliant Joint for Human-friendly Service Robots

  • Yoon, Seong-Sik;Sungchul Kang;Kim, Seung-Jong;Kim, Munsang;Yim, Heung-Soon;Kim, Young-Hwan
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.119.2-119
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    • 2002
  • In this paper a passive compliant joint (PCJ) for human-friendly service robots is presented. The PCJ is composed of a magneto-rheological damper and a spring for elasticity. In the magneto-rheological damper, a braking force proportional to the electric current is generated. It works as a viscous damper by controlling the electric current according to the angular velocity of spring displacement. The compliance property and position control of the PCJ are verified through experiments and simulations to a single DOF simple arm with the PCJ.

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A Study of Friction Characteristics in Magneto-Rheological Elastomer (자기유변탄성체 액츄에이터의 마찰특성 연구)

  • Lee, Deuk-Won;Lee, Chul-Hee;Kim, Cheol-Hyun;Cho, Won-Oh
    • Tribology and Lubricants
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    • v.27 no.4
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    • pp.213-217
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    • 2011
  • In this study, friction characteristics using elastomeric actuator with Magneto-rheological (MR) materials are identified. Typically, Magneto-rheological materials are divided into two groups by MR fluid in fluid state and MR elastomer in solid state like rubber. The stiffness characteristics of Magneto-rheological material can be changed as magnetic field is applied. MR fluid has been applied to various industry fields such as to brake, clutch, damper, engine mount and etc. However, MR fluid has been used under the sealed condition to prevent leaking issues. In order to overcome these problems, MR elastomer that has same property as MR fluid has been developed and studied. MR elastomer mainly consists of polymer material such as natural rubber or silicon rubber with particles that can be polarized with magnetic field. And it is called as a smart material since its stiffness and damping characteristics can be changed. In this study, MR elastomer is produced and pin-on-disc tests are carried out to identify the friction characteristics of the material. Several test conditions are applied to evaluate the feasibility to use as a smart actuator in the field of vibration control.

Development and Evaluation of a Hybrid Damper for Semi-active Suspension (반능동 현가장치의 하이브리드형 댐퍼 개발에 관한 연구)

  • Jin, Chul Ho;Yoon, Young Won;Lee, Jae Hak
    • Journal of Drive and Control
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    • v.15 no.1
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    • pp.38-49
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    • 2018
  • This research describes the development model and testing of a hybrid damper which can be applicable to a vehicle suspension. The hybrid damper is devised to improve the performance of a conventional passive oil damper using a magneto-rheological (MR) accumulator which consists of a gas accumulator and a MR device. The level of damping is continuously variable by the means of control in the applied current in a MR device fitted to a floating piston which separates the gas and the oil chamber. A simple MR device is used to resist the movement of floating piston. At first a mathematical model which describes all flows within the conventional oil damper is formulated, and then a small MR device is also devised and adopted to a mathematical model to characterize the performance of the device.

Development of Rehabilitation Training System Using Unstable Flatform with Magneto-Rheological Damper (MR 댐퍼 적용 불안정판을 이용한 재활 훈련시스템 개발)

  • Choi, Youn-Jung;Piao, Yong-Jun;Heo, Min;Kwon, Tae-Kyu;Hwang, Ji-Hye;Kim, Dong-Wook;Kim, Nam-Gyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.2
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    • pp.197-204
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    • 2008
  • The purpose of this paper was to develop a rehabilitation training system which is controlled by electric currents to the Magneto-Rheological dampers system. This system provided the function for the training of the unbalance of the lower extremities. 10 subjects executed the tracing and moving exercises which are presented through the display monitor and confirmed own the capability of performance on the task. The electromyographies of the four muscles in lower extremities were recorded and analyzed in the time and frequency domain the muscles of interest were rectus femoris, biceps femoris, gastrocnemius, tibialis anterior. The experimental results showed that subjects had a task under feedback mode then subjects improve the capability of performance, increasing the in time, decreasing the out time and the distance of body shift. The moving average EMG, spectral energy of four muscle is lower the feedback mode than the constant mode. This could aid the hemiplegic patients to train more easily.

Performance Analysis with Different Tire Pressure of Quarter-vehicle System Featuring MR Damper (MR 댐퍼를 장착한 1/4차량의 타이어 공기압에 따른 성능분석)

  • Sung, Kum-Gil;Lee, Ho-Guen;Choi, Seung-Bok;Park, Min-Kyu;Park, Myung-Kyu
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.3
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    • pp.249-256
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    • 2010
  • This paper presents performance analysis of a quarter-vehicle magneto-rheological(MR) suspension system with respect to different tire pressure. As a first step, MR damper is designed and manufactured based on the optimized damping force levels and mechanical dimensions required for a commercial mid-sized passenger vehicle. After experimentally evaluating dynamic characteristics of the manufactured MR damper, the quarter-vehicle MR suspension system consisting of sprung mass, spring, tire and the MR damper is constructed in order to investigate the ride comfort. After deriving the equations of the motion for the proposed quarter-vehicle MR suspension system, vertical tire stiffness with respect to different tire pressure is experimentally identified. The skyhook controller is then implemented for the realization of quarter-vehicle MR suspension system. Ride comfort characteristics such as vertical acceleration RMS and weighted RMS of sprung mass are evaluated under various road conditions.