• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.2
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• pp.1-7
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• 2007

Active magnetic bearing has been adopted to support the rotor by electomagnetic force without mechanical contact and lubrication process. A property of the control system for magnetic bearing is improved in accordance with making higher system gain. If the control system has integral part, an excessive overshoot response is shown by making higher integral gain. Therefore, this paper suggests a PID control system in order to eliminate the overshoot at the first stage and improve response characteristics to an impact disturbance at the status of levitation. The control gain was obtained by LQR design method which has the structure of I-PD control system in the state space. The PID control system containing prefilter has the same structure as the I-PD control system. Therefore, the PID control system adopted is able to be tuned by LQR design method. Finally, this paper shows the effect of the prefilter on the active magnetic bearing system through response experiments for levitation responses.

• Journal of the Korean Magnetics Society
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• v.9 no.1
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• pp.48-54
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• 1999

For the high speed linear motor and the transportation device at clean room, a magnetic levitation rail without contact using the repulsive force of permanent magnets was newly developed. The characteristics of repulsive and lateral forces of the magnetic levitating system using permanent magnet was studied and the devised magnetic levitating system was evaluated by analytical and experimental approaches. This system is composed of two fixed guide rails with the rare earth permanent magnet array and a moving unit which is attached two magnet pairs at each sides. Because this system was forcedly levitated by the face to face repulsive forces, levitating air gap length can be repulsive force of an auxiliary magnetic repulsion system on the center of moving unit.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.792-800
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• 2021

This paper presents a new structure for a linear active magnetic bearing using a Halbach magnet array. The proposed magnetic bearing consisted of a Halbach magnet array, center magnet, and single coil. The proposed linear active magnetic bearing has a high dynamic force compared to the previous study. The high dynamic force could be obtained by varying the thickness of a horizontally magnetized magnet. The new structure of Halbach linear active magnetic bearing has a high dynamic force. Therefore, the proposed linear active magnetic bearing increased the bandwidth of the system. Magnetic modeling and optimal design of the new structure of the Halbach linear active magnetic bearing were performed. The optimal design was executed on the geometric parameters of the proposed linear active magnetic bearing using Sequential Quadratic Programming. The proposed linear active magnetic bearing had a static force of 45.06 N and a Lorentz force constant of 19.54 N/A, which is higher than previous research.

• Journal of Engineering Education Research
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• v.8 no.1
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• pp.5-19
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• 2005

This paper describes the design and fabrication of magnetic levitation kits for use in the hands on experiments of automatic control, digital control and microprocessor applications in the division of mechatronics in Samcheok university. The kits are developed inspired by MIT's design, but it is designed on the digital basis, whereas MIT's is designed on the analog basis. As a result, the kits can be monitored and controlled on the analog and digital control techniques. Furthermore, the cost of kit components is comparable or lower to that of MIT design. And the kits can be controlled with magnetic hall sensors and/or infrared sensors, which provides more versatile experience on the use of sensors and signal filtering to the students. The design is fabricated and tested by authors and will be provided to the students as lab projects. The kits will be intentionally presented with a device that is poorly instrumented and poorly compensated. And the students are expected to analyze sensor signal and controller performance, and then, perform compensator design and signal filtering.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1047-1048
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• 2010

• 한국초전도학회:학술대회논문집
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• 2007.07a
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• pp.88-88
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• 2007

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.127-130
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• 1991

A magnetic levitation system with hybrid magnets, which is composed of permanent magnets and electromagnets, consumes less power than the conventional attraction type system. A parallel complementary controller on the lift controller is proposed to reduce the sensitivity for parameter variation and force disturbance. Simulation and experiment show that the lift system has robustness to force disturbance.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.735-736
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• 2006

In this paper, the characteristics analysis results of the levitation controller of magnetically-levitated vehicle are presented. To get a good closed-loop system, the observer and controller must be designed to meet the control performance and ride quality requirements. So the transfer functions of the observer filter are described and analysed by using the relative and absolute signal concepts.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.46-49
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• 1995

This paper deals with characteristics of magnet that the levitation and guidance forces at static state and we tested and evaluated its. Also we compared to effect of levitation force with material and shape of guide way, focus on evaluation and method of test for the magnet of Urban Transit Maglev vehicle.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.2 no.3
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• pp.17-25
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• 1991

Magnetic leakage flux which is generated from the levitation magnets, linear induction motors, and guide magnets of a MagLev(Magnetic Levitation) system is directly related to inter - system EMI, intra - system EMI, and biological effects. In this paper, the magnetic leakage flux from MagLev vechicles designed by Korea Resarch Institute of Ships & Ocean Engineering was calculated considering the various parameters which influence ma- gnetic field intensity around the MagLev system. Based on the calculated field intensity, the thickness of shielding material and shielding position for MagLev floor and side walls are calculated, taking into account the shielding effectiveness of a shield with minimum weight. For the nonuniform shielding method derived from the above procedure, the weight of a shield con- sisting of floor and side walls shielding can be reduced to more 50% than uniform shielding method.