• Title/Summary/Keyword: Magnetic control

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Disturbance Compensation Control of An Active Magnetic Bearing System by Multiple FXLMS Algorithm - Experiments (MFXLMS 알고리즘을 이용한 전자기베어링계의 외란보상 제어기 - 실험)

  • 강민식;정종수
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.2
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    • pp.83-91
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    • 2004
  • This paper illustrates the feasibility and the effectiveness of the disturbance feedforward compensation control proposed in the previous paper. The compensator is designed experimentally by means of the Multiple Filtered-x Least Mean Square algorithm. A 2-DOF active magnetic bearing system subject to base motion is built and the compensation control is applied. The experimental results demonstrate that the compensation control reduces the air-gap responses within 10$%$ of those by the feedback control alone without increasing the control inputs.

Modeling and Control of Cone-Shaped Active Magnetic Bearing System (원추형 능동 자기베어링계의 모형화 및 제어)

  • 정호섭;김철순;이종원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.12
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    • pp.3073-3082
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    • 1993
  • A magnetically suspended robot joint is developed, which is free of dust and oil generation. Two radial bearings consisting of cone-shaped magnet cores control the rotor motion in the axial and radial directions. A linearized dynamic model is developed for active control of the magnetic bearing system. The control algorithm is constructed such that the axial displacement of the joint is controlled by radial control current to the pairs of facing radial bearings. The stability and control performance is tested through numerical simulation based on the nonlinear model. Experiments are also performed to verify the theoretical development.

Base Acceleration Feedforward Control for an Active Magnetic Bearing System Subject to Base Motion (베이스 가진을 받는 전자기 베어링계의 베이스 가속도 앞먹임 제어)

  • Kang, Min-Sig
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.1028-1033
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    • 2002
  • This paper concerns on a non-rotating axis-active magnetic bearing (AMB) system subject to base motion. In such a system, it is desirable to retain the axis within the predetermined air-gap. Motivated from this, an optimal acceleration feedforward control is proposed to reduce the base motion response without deteriorating other feedback control performances. Experimental results demonstrate that the proposed feedforward control reduces the air-gap deviation to 29% that by feedback control alone.

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Disturbance Compensation Control in Active Magnetic Bearing Systems by Filtered-x LMS Algorithm (전자기베어링에서 Filtered-x LMS 알고리즘을 이용한 외란보상 제어기 설계)

  • 강민식;강윤식;이대옥
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.447-450
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    • 2003
  • This paper concerns on application of active magnetic bearing(AMB) system to levitate the elevation axis of an electro-optical sight mounted on moving vehicles. In such a system. it is desirable to retain the elevation axis within the predetermined air-gap while the vehicle is moving. A disturbance compensation control is proposed to reduce the base motion response. In the consideration of the uncertainty of the system model, a filtered-x least-mean-square(FXLMS) algorithm is used to estimate adaptively the frequency response function of the feedforward control which cancels disturbance responses. The frequency response function is fitted to an optimal feedforward control. Experimental results demonstrate that the proposed control reduces the air-gap deviation to 27.7% that by feedback control alone.

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Acceleration Feedforward Control in Active Magnetic Bearing System Subject to Base Motion by Filtered-x LMS Algorithm (베이스 가진을 받는 능동자기베어링 시스템에서 Filtered-x LMS 알고리듬을 이용한 가속도 앞먹임 제어)

  • Kang, Min-Sig
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.10
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    • pp.1712-1719
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    • 2003
  • This paper concerns on application of active magnetic bearing(AMB) system to levitate the elevation axis of an electro-optical sight mounted on moving vehicles. In such a system, it is desirable to retain the elevation axis within the predetermined air-gap while the vehicle is moving. An optimal base acceleration feedforward control is proposed to reduce the base motion response. In the consideration of the uncertainty of the system model, a filtered-x least-mean-square(FXLMS) algorithm is used to estimate the frequency response function of the feedforward control which cancels base motions. The frequency response function is fitted to an optimal feedforward control. Experimental results demonstrate that the proposed control reduces the air-gap deviation to 27.7% that by feedback control alone.

Control of Conductive Plate Through Varying the Open Area Size of the Partially, Magnetically Isolated Electrodyamic Wheel (부분 차폐된 동전기 휠의 개방 영역 크기 조절을 통한 전도성 평판의 제어)

  • Jung, Kwang-Suk
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.3
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    • pp.230-236
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    • 2012
  • Shielding the air-gap magnetic field of the electrodynamic wheel below a conductive plate and opening the shielding plate partially, a thrust force and a normal force generate on the conductive plate at the open area. But, as only the variable controlling both forces is a rotating speed of the electrodynamic wheel, it is very difficult to control the forces independently by the speed. So, we discuss a novel method controlling the forces effectively through manipulating a size of the open area. The independent control is made possible by virtue of the feature that the relative ratio between both forces is irrelevant to an air-gap length and determined uniquely for a specific rotating speed of the wheel. Therefore, the rotating speed and the size of open area become new control variables. The feasibility of the method is verified experimentally. Specially, the controllable magnetic forces are used in a noncontact conveyance of the conductive plate.

A Suspension Control of A PM-based Magnetic Suspension System (영구자석을 포함한 자기부상시스템의 부상제어)

  • Kim, Jong-Moon;Kim, Choon-Kyung;Park, Min-Kook;Chun, Jong-Min;Pyon, Han-Sub
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.2264-2266
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    • 2001
  • In this paper, some suspension results for a magnetic suspension system with permanent magnet are presented. The electromagnetic model using the equivalent magnetic circuit is shown. And some control simulation results using Matlab/Simulink S/W are presented.

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Modelling and Controller Design of Electro-Magnetic Valve for Vehicle Engine (차량 엔진용 전자기식 밸브의 모델링 및 제어기 설계)

  • Jung, Y.S.
    • Journal of Power System Engineering
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    • v.6 no.4
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    • pp.81-87
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    • 2002
  • The modelling and controller design of the EMV(electro-magnetic valve) for vehicle engine are considered in this paper. For the analysis and controller design, the governing equation of the EMV system is derived. For a good performance of the system, the start control, the holding control and the swing control are included in the controller design of the EMV system. In order to reduce landing speed of the valve, the on-time delay control which mainly come from the optimal control theory is employed. In order to reduce the power consumption of the system, the pick-up and hold operation has been used for the magnetic coil. The simulation and experimental results are presented to show the validity of the control method.

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Size Control of Iron Oxide (Fe3O4) Nanoclusters according to Reaction Factors and Consequent Change in Their Magnetic Attraction (반응 인자 제어에 의한 산화철(Fe3O4) 나노클러스터의 크기와 자기 특성 조절)

  • Sanghoon Lee;Arim Byun;Jin-sil Choi
    • Journal of Powder Materials
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    • v.30 no.4
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    • pp.297-304
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    • 2023
  • Iron oxide (Fe2O3) nanoclusters exhibit significant potential in the biomedical and pharmaceutical fields due to their strong magnetic properties, stability in solutions, and compatibility with living systems. They excel in magnetic separation processes, displaying high responsiveness to external magnetic fields. In contrast to conventional Fe2O3 nanoparticles that can aggregate in aqueous solutions due to their ferrimagnetic properties, these nanoclusters, composed of multiple nanoparticles, maintain their magnetic traits even when scaled to hundreds of nanometers. In this study, we develop a simple method using solvothermal synthesis to precisely control the size of nanoclusters. By adjusting precursor materials and reducing agents, we successfully control the particle sizes within the range of 90 to 420 nm. Our study not only enhances the understanding of nanocluster creation but also offers ways to improve their properties for applications such as magnetic separation. This is supported by our experimental results highlighting their size-dependent magnetic response in water. This study has the potential to advance both the knowledge and practical utilization of Fe2O3 nanoclusters in various applications.

A New Algorithm of B-waveform Control for the Measurement of Two-dimensional Magnetic Properties of Electrical Steel Sheets using Single Sheet Tester (SST를 이용한 전기강판의 2차원 자기특성 측정을 위한 새로운 자속밀도 파형 제어법)

  • Eum, Young-Hwan;Yoon, Hee-Sung;Koh, Chang-Seop
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.7
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    • pp.1167-1174
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    • 2008
  • The measurement of two-dimensional magnetic properties of electrical steel sheet using single sheet tester (SST) requires to control the B-waveform as sinusoidal. The SST electric circuit, in general, has inductance, and this makes the phase lag in electric current. For this reason, the induced voltages of H- or B-coil may have phase difference from the exciting voltage. In this paper, a new algorithm is developed to compensate the phase difference and makes the B-waveform control efficient. The developed algorithm experimentally calculates the phase difference based on the measured waveform of the induced voltage for the magnetic field intensity along transverse direction. By using the proposed algorithm, the two-dimensional magnetic properties of grain-orientated electrical steel sheet (30PG110) is measured up to 2T. By comparing the measured B- and H-waveforms, the effectiveness of the proposed algorithm is proven.