• Title/Summary/Keyword: Levitation Control

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Development of Redundant Levitation and Guidance Control System of the Urban and Medium to High Speed Magnetic Levitation Train

  • Cho, Yeon-Hwa;Lee, Sun-Hee;Jang, Kyung-Hyun;Lee, Sang Suk;Lee, Kyoung-Bok;Park, Doh-Young
    • International Journal of Railway
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    • v.8 no.1
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    • pp.21-29
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    • 2015
  • This study focuses on the performance enhancement of the levitation and guidance control system in urban and medium-to high-speed magnetic levitation trains. A levitation control system, which is currently being tested in Yeongjongdo, is a single controller that is neither designed nor produced on the basis of redundancy. Hence, vehicular stability and reliability should be improved for the situation in which levitation failure occurs because of a breakdown in a controller during vehicle operation. In addition, the control system should be developed to control electromagnetic levitation considering changes in normal force according to changes in the driving force of the propulsion system.

Development of Levitation Control for High Accuracy Magnetic Levitation Transport System (초정밀 자기부상 이송장치의 부상제어기 개발)

  • Ha, Chang-Wan;Kim, Chang-Hyun;Lim, Jaewon
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.7
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    • pp.557-561
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    • 2016
  • Recently, in the manufacturing process of flat panel displays, mass production methods of inline system has been emerged. In particular the next generation OLED display manufacturing process, horizontal inline evaporation process has been tried. It is important for the success of OLED inline evaporation process to develop a magnetic levitation transport system capable of transferring a carrier equipped with a mother glass with high accuracy without any physical contact along the rail under vacuum condition. In the case of existing wheel-based transfer system, it is not suitable for OLED evaporation process requiring high cleanliness. On the other hand, the magnetic levitation transport system has an advantage that it does not generate any dust and it is possible to achieve high-precision control because there are not non-linear factors such as friction force. In this paper, we introduce the high-precision magnetic levitation transport system, which is currently under development, for OLED evaporation process.

Zero Power Levitation Control of Hybrid Electro-Magnetic Levitation System by Load Observer (부하 상태관측기에 의한 하이브리드 부상 시스템의 제로 파워 부상 제어)

  • Kim, Youn-Hyun;Lee, Ju
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.50 no.6
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    • pp.282-289
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    • 2001
  • This paper introduces the scheme that improve the control performance of electromagnetic levitation system with zero power controller. Magnetic levitation is used widely, but the electromagnetic force has nonlinear characteristics because it is proportioned to a square of the magnetic flux density and it is in inverse proportion to a square of the airgap. So, it is complicate and difficult to control the electromagnetic force. Besides, it is more difficult to control if the equivalent gap is unknown in case of zero power control. Therefore, this paper proposed the hybrid electro-magnetic levitation control method in which the variable load is estimated by using a load observer and its system controlled at a new zero power equilibrium airgap position. Also it is confirmed that the proposed control method improve the control performance through simulation and experiment.

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Zero Power Levitation Control of Controlled-PM Electromagnet Levitation System by Reduced Order Extended State Observer (최소차원 확장형 상태관측기에 의한 제어형 영구자석 자기 부상 시스템의 제로전력 부상 제어)

  • Kim, Youn-Hyun;Kim, Sol;Lee, Ju
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.51 no.9
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    • pp.515-521
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    • 2002
  • This paper presents the scheme that improves control responsibility and stability of the controlled-PM electromagnet levitation system with zero Power controller. A magnetically levitation system is used widely because friction can almost be disappeared. But it is difficult to control due to restraint of controllable area and nonlinear characteristics of electromagnetic force, which is proportioned to a square of the magnetic flux density and is in inverse proportion to a square of the air-gap. So, the application of observer theory in which the levitation system is considered to be a linear dynamic model has resulted in omitting the time dependence on mover's speed. Consequently, the performance of the observer is quite poor during transients. Therefore, this paper proposed the controlled-PM electro-magnetic levitation control method in which the variable load is estimated by using the reduced order extended luenverger observer and its system is controlled at a new zero power equilibrium air-gap position. It is also verified that the proposed control method improve the control performance through simulation and experiment.

Output Improvement of a Magnetic Levitation Control System

  • Jung, Hae-Young;Na, Seung -You
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1995.10b
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    • pp.59-70
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    • 1995
  • Output performance improvement using fuzzy logic to the conventional control scheme for a magnetic levitation system is presented in this paper, Adverse characteristics of nonlinearity, unstability, system parameter variation, etc, in the levitation system are partially overcome by the general fuzzy control action. Using a PD type compensator, a coarse framework of output performance is provided to the levitation system. Then a fine regulation to the output performance requirement is obtained by the natural description of the control action in the form of fuzzy logic controller. This control action soothes the adverse characteristics of the levitation system. In this way a better output performance can be obtained in a real time experiment.

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AN EFFICIENT SENEOR ARRAY FOR A LATFE-GAP MAGNETIC LEVITATION SYSTEM

  • Na, Seung-You;Shin, Dae-Jung
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.154-157
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    • 1995
  • A magnetic levitation control system is nonlinear and very unstable. Thus there should be a stabilizing compensation network and a feedback path. Due to the levitation control a noncontact photoresistor sensor is generally used. One photocell provides a certain amount of variation in length by the ball shadow casted on the cell surface. Furthermore at the boundary of the cell, the linearity of sensitivity deteriorates severely. To overcome the constraints of the length and linearity, an efficient sensor array is deviced and applied in the feedback path of a large-gap magnetic levitation control system. A number of CdS photocells and a summing circuit of the sensor output signals are used for a sensor array. The levitation length of a ball and the transient performances are main objectives of the large-gap suspension system using the sensor array.

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Design of Levitation and Propulsion Controller for Magnetic Levitated Logistic Transportation System (자기부상 물류이송시스템의 부상 및 추진제어기 설계)

  • Choi, Dae-Gyu;Kim, Yong-Tae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.27 no.2
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    • pp.106-112
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    • 2017
  • In the paper, we propose a levitation and a propulsion controller for the magnetic levitation logistic transportation system. The levitation controller is designed considering the mutual influence of the electromagnets to minimize roll and pitch movements. In order to solve the structural disadvantages of the magnetic levitation transportation system, we improve the problem of the existing controller by applying the exponential filter to the reference input. DSP-based control hardware is developed and the levitation control method is verified by levitation experiments to the air gap goal. The propulsion controller uses the space vector voltage modulation method. The propulsion controller is designed to follow the position and velocity profile by detecting the absolute position from the bar code information attached to the rail. The position control result shows satisfactory performance through the propulsion control reciprocating motion experiment.

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.

Control Strategy and Algorithm for Levitation of Over-actuated Passive Maglev Tray System (과구동 자기부상 무전원 트레이의 부상제어 전략 및 자세제어 알고리즘)

  • Ahn, Changsun
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.6
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    • pp.553-562
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    • 2015
  • This paper presents a strategy and an algorithm for levitation control of an over-actuated passive maglev tray system. The passive maglev tray system has more actuators than its degrees of freedom. The actuators of the system are switching when the tray travels longitudinally. Furthermore, the levitation forces of the actuators are non-homogeneous because the actuation devices are not in the moving platform. These characteristics make a limit in using conventional control approaches for levitation. For smooth actuator switching, the actuator force generation should be dependent on longitudinal positions of the tray. To enable constant pose tracking, this research introduces a control strategy and a control algorithm based on integral controllers on virtual variables. The states of the tray are estimated using a Kalman filter and fed to the proposed controller. The performances of the proposed control strategy and the algorithm are validated through tests.

A Study on Air-gap Control for Transverse Flux Permanent Magnet Type Magnetic Levitation Electromagnet System (횡자속 영구자석형 자기부상전자석 시스템의 공극제어에 관한 연구)

  • Jae-Won Lee;Myeong-Jae Kim;Seon-Hwan Hwang
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.6_2
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    • pp.1127-1134
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    • 2023
  • In this paper, we proposes a study on air gap control for magnetic levitation of transverse flux permanent magnet electromagnets. In general, mechanical systems have a high failure rate of bearings. Bearings in particular are problematic because they have high surface wear rate and degradations. To solve this problem, replacing the bearing with a magnetic levitation electromagnet system can provide lightweight and efficiency improvements. However, precise air gap control is essential to control the magnetic levitation electromagnet system. Therefore, in this paper, we identify the instable cause of gap control through a mathematical modeling and verify through experiment a control algorithm that can use compensation.