• Title, Summary, Keyword: Magnetic levitation

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A New Model of Magnetic Force in Magnetic Levitation Systems

  • Lee, Y.S.;Yang, J.H.;Shim, S.Y.
    • Journal of Electrical Engineering and Technology
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    • v.3 no.4
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    • pp.584-592
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    • 2008
  • In this paper, we propose a new model of the magnetic control force exerted on the levitation object in magnetic levitation systems. The model assumes that the magnetic force is a function of the voltage applied to an electromagnet and the position of a levitation object. The function is not explicitly expressed but represented through a 2D lookup table constructed from the experimentally measured data. Unlike the conventional model that reveals only local characteristics of the magnetic force, the proposed model shows global characteristics satisfactorily. Specially devised measurement equipment is utilized in order to gather the data required for model construction. An experimental procedure to construct the model is presented. We apply the proposed model to designing a sliding mode controller for a lab-built magnetic system. The validity of the proposed model is illustrated by comparing the performances of the controller adopting the conventional model with that of the controller adopting the proposed model.

Study on Dynamic Analysis of Magnetic Levitation Vehicles (자기부상열차의 동적 해석 연구)

  • 한형석;조흥제;김대진
    • Proceedings of the KSR Conference
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    • pp.218-225
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    • 1999
  • Dynamic analysis of the magnetic levitation vehicle UTM01 is studied using the multibody dynamic analysis program DADS. The magnetic levitation force is defined and incorporated into DADS through the user-defined subroutines of DADS. The vehicle with bogies is modeled in 3 dimension. The developed vehicle model with magnetic nodules is analyzed for two rail profiles. The results show that the presented method is applicable to magnetic levitation vehicles.

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A Study on the Design of Robust Controller of Magnetic Levitation System(II) (자기부상 시스템에 강인한 제어기 설계에 관한 연구 (II) - 실험을 중심으로 -)

  • 김창화;양주호;김영복
    • Journal of Advanced Marine Engineering and Technology
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    • v.20 no.3
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    • pp.144-153
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    • 1996
  • The magnetic levitation system has many advantages, such as little friction, no lubrication, no noise and so on. For this reason, the magnetic levitation system is utilized in the magnetic bearing of high-speed rotor. The method to obtain magnetic force is both the repulsive suspension method and the attraction suspension method need a stabilizing controller because it is a unstable system in natural. This paper presents the design of robust stabilizing servo controller in spite of being the model uncertainties in the magnetic levitation system by $\textit{H}_{\infty}$ control theory using the free parameter. And we investigated the validity of a designed controller through results of the simulation and the actual experiment.

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A Single DOF Magnetic Levitation System using Time Delay Control and Reduced-Order Observer

  • Park, Jung-Soo;Baek, Yoon-Su
    • Journal of Mechanical Science and Technology
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    • v.16 no.12
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    • pp.1643-1651
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    • 2002
  • Magnetic levitation systems are required to have a large operating range in many applications. As one method to solve this problem, Time Delay Control (TDC) is applied to a single-axis magnetic levitation system in this paper A reduced-order observer is utilized to estimate states excluding measurable states in the control law. The system consists of a square air-core solenoid and a circular permanent magnet attached on a plastic ball. Theoretical magnetic forces of the system are obtained on the basis of the location of the magnet around the solenoid. The magnetic levitation force is obtained by the experiment, and then compared with the theoretical one. As the results of the control experiments, the nonlinear controller (TDC : 1-2 ㎜) has a larger operating range than the linear controller (PD control : 1-1.4 ㎜), and is superior to linear. control in the robustness to the modeling uncertainty and the performance of the disturbance rejection.

Novel Cylindrical Magnetic Levitation Stage for Rotation as well as Translation along Axles with High Precisions (고정밀 회전 및 축방향 이송을 위한 신개념 원통형 자기부상 스테이지)

  • Jeon, Jeong-Woo;Caraiani, Mitica;Lee, Chang-Lin;Jeong, Yeon-Ho;Kim, Jong-Moon;Oh, Hyeon-Seok;Kim, Sungshin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.12
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    • pp.1828-1835
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    • 2012
  • In this paper, a conceptual design and a detailed design of novel cylindrical magnetic levitation stage is introduced. This is came from planar-typed magnetic levitation stage. The proposed stage is composed of cylinder-typed permanent magnet array and semi-cylinder-typed 3 phase winding module. When a proper current is induced at winding module, a magnetic levitation force between the permanent magnet array and winding module is generated. The proposed stage can precisely move the cylinder to rotations and translations as well as levitations with the magnetic levitation force. This advantage is useful to make a nano patterning on the surface of cylindrical specimen by using electron beam lithography under vacuum. Two methods are used to calculate required magnetic levitation forces. The one is 2D FEM analysis, the other is mathematical modeling. This paper shown that results of two methods are similar. An assistant plate is introduced to reduce required currents of winding module for levitations in vacuum. The mathematical model of cylindrical magnetic levitation stage is used for dynamic simulation of magnetic levitations. A lead-lag compensator is used for control of the model. Simulation results shown that the detail designed model of the cylindrical magnetic levitation stage with the assistant plate can be controlled very well.

Implementation of permanent Magnetic Repulsion Type of Magnetic Levitation Table Using One Degree-of-freedom Active Control (1 자유도 능동제어에 의한 영구자석 반발형 자기부상 테이블의 구현)

  • Jo, Yeong-Geun;Choe, Gi-Bong;Tadahiko Shinshi;Akira Shimokohbe
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.7
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    • pp.125-132
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    • 2002
  • This paper shows an experimental magnetic levitation table using one degree-of-freedom active control. The magnetic levitation table using repulsions of permanent magnets was theoretically presented already. Thus the objective of this paper is to prove stable levitation with only one degree-of-freedom active control experimentally. For the design of the system, at first, permanent magnets are selected. Secondly, the spring constants of the virtual spring are obtained by simulation. Thirdly, the moving magnets are arranged using a stable layout relation. Fourthly, a linear voice coil motor is designed. Finally, the magnetic levitation system is manufactured. The phenomenon of stable levitation in the manufactured table is proven by means of dynamic time and frequency responses. The differences between the theoretical natural frequencies and experimental ones are analyzed. Also, stable range in the control direction is shown experimentally.

A Study on the Control System Design of Sensorless Magnetic Levitation System (센서리스 자기 부상계의 제어계 설계에 관한 연구)

  • 김창화;김영복;양주호
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.175-181
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    • 1996
  • The magnetic levitation system is utilized in the magnetic bearing of high-speed rotor because of little friction, no lubrication, no noise and so on. The magnetic levitation system need the feedback controller for the stabilization of system, and gap sensors are usually used to measure the gap. The use of sensor is troublesome such as sensor trouble, discord between the measurement point and the control point etc. This paper presents the design of robust stabilizing controller by H$_{\infty}$ control theory using the sensorless method proposed already by authors in the magnetic levitation system. And we investigated both the validity of the designed controller and the usefulness of the sensorless method proposed by authors of magnetic levitation system through results of actual experiment..

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A Robustness Control of Magnetic Levitation System Using Linear Matrix Inequality (선형행렬부등식을 이용한 자기 부상계의 강인성 제어)

  • Kim, C.H.;Yang, J.H.
    • Journal of Power System Engineering
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    • v.3 no.4
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    • pp.79-85
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    • 1999
  • The magnetic levitation system is utilized in the magnetic bearing of high-speed rotor system because of little friction, no lubrication, no noise and so on. The magnetic levitation system needs the feedback controller for the stabilization of system, and gap sensors are generally used to measure the gap. The use of sensor easily goes into troublesome caused by sensor failure discord between the measurement point and the control point etc. This paper gives a controller design method of magnetic levitation system which satisfies the given $H_{\infty}$ control performance and the robust stability of the presence of physical parameter perturbations. To the end, we investigated the validity of the designed controller through results of simulation.

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A Study on the Gap Estimation Circuit Design of the Magnetic Levitation System (자기 부상계의 변위추정 회로설계에 관한 연구)

  • Kim, C.H.;Ha, Y.W.;Sim, S.H.;Yang, J.H.
    • Journal of Power System Engineering
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    • v.1 no.1
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    • pp.144-153
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    • 1997
  • The magnetic levitation system is utilized in the magnetic bearing of high-speed rotor because of little friction, no lubrication, no noise and so on. The magnetic levitation system need the feedback controller for the stabilization of system, and gap sensors are generally used to measure the gap. The use of gap sensors brings out the increase of the number of troublesome, and the decrease of the control performance because of the dislocation between the measurement point and the control point. This paper presents the design of the gap estimation circuit for the sensorless method proposed by authors in the magnetic levitation system. We made the gap estimation circuit which was composed of both the superposition circuit and the measuring circuit. And we investigated the validity of the usefulness of the proposed sensorless method in the magnetic levitation system through results of actual experiment.

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