• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.1133-1136
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• 1999

A magnetic levitation control system is inherently nonlinear and very unstable. Thus there should be a stabilizing compensator network and a negative feedback path using noncontact photoresistor or ultrasonic sensors for the levitation operation. Since the photo sensor plays a key role in the system, the steady-state error and transient performance of the overall system depend on the characteristics of the sensors. But the sensor itself also suffers from nonlinearity, and the magnitude of sensor input heavily depends on environmental conditions. To improve the output performance, we added a linearizing circuit for the sensor characteristics and a disturbance cancelation circuit to avoid sensitive output due to extraneous interfering light.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.155-157
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• 2003

In this paper, CPM(controlled-permanent magnet)-type magnetic levitation system design is presented. The target plant to be controlled consists of eight magnets with permanent magnet and electromagnet. The design procedure is also described and the result of this work is shown.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.253-255
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• 2004

Conventional magnetic levitation systems could show unsatisfactory performance under air-gap disturbance due to rail irregularities. In this paper, we propose a feedback control system with discrete Kalman filter for air-gap disturbance attenuation. It is shown that excellent system performance can be obtained with the use of discrete Kalman filter, and that results from experiments agree well with those of simulations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.415-418
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• 2005

In the semiconductor and optical industry, a new transport system which can replace the conventional transport systems is required. The transport systems are driven by the magnetic field and conveyer belts. The magnetic field may damage semiconductor and the contact force may scratch the optical lens. The ultrasonic wave driven system can solve these problems. In this semiconductor and optical industry, the non-contact system is required fur reducing the damages. The ultrasonic transportation is the solution of the problem. In this paper, the ultrasonic levitation system fur levitating object are proposed. The 3D vibration profiles of the beam are measured by Laser scanning Vibrometer fur verifying the vibration characteristics of the system and the amplitudes of the beam and the levitation heights of object are measured for evaluating the performance.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.95-98
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• 1998

Applying the magnetically levitated transportation system, which is noncontact bearing system, to solve the problems such as transformation of original form or flaw of iron plate caused by transportation of thin iron plate which required high quality as body of motor vehicle, materials of electronic devices etc.. Magnetic saturation phenomena caused by thickness of iron plate and gap size between magnets. In case of iron plate, the vibration mode will be considered since vibration occurs during transportation. In order to solve the problems caused by vibration, choose the levitation system method using numbers of magnet, magnetic saturation for thickness and length of iron plate with parameters in location and gap of magnet. In this paper, we will suggest the whole design technique of magnetically levitated transportation system, namely method of magnetic attraction and transportation system

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1605-1610
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• 2010

In this paper, the relative stability of magnetic bearing system for the flywheel energy storage is evaluated using both simulation and experimental analysis. We make the simulation model for the magnetic bearing flywheel system using the rigid body shaft model. According to international standard ISO 14839-3, We experimentally analyzed the relative stability of magnetic bearing system. Additionally using both the simulation model and experimental tests, Phase margin and Gain margin is acquired through Nyquist plot.

• Journal of the Korean Society for Railway
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• v.13 no.3
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• pp.278-282
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• 2010

Since a power supply substation of the magnetic levitation train system includes a inverter which is necessary to change the frequency of power, it has a different characteristic comparing to any other railway system. Nowaday a study for determining rating of facilities constituting a power supply system and modeling that system is undergoing. In this paper, a analysis model for the power supply system of the magnetic levitation train using the 3-level inverter is proposed. And the analysis for output characteristic is performed using the PSCAD/EMTDC program. The control method about the output of 3-level inverter for supplying power to loads in magnetic levitation train system is also described.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.48.4-48
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• 2001

Major objective of this paper is to develop the sliding mode control method for a nonlinear electro magnetic levitation system governed by a set of a second-order motion equation and a first-order electromagnetic equation. Simulations for initial responses were carried out to confirm the validity of the present design method.

• Journal of Electrical Engineering and Technology
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• v.7 no.4
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• pp.558-563
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• 2012

In this paper, a novel planar type magnetic levitation system without other assistant devices is proposed and it can move with 6 degree of freedom (X, Y, Z, ${\theta}_X$, ${\theta}_Y$, ${\theta}_Z$) in wafer size as well as in nano scale positioning.The mover is composed with 2-D Halbach permanent magnet array and the stator is composed with $10{\times}10$ coil arrays.It was composed in laboratory and tested with short stroke (4 [mm]) and long stroke (160 [mm])movements. The errors of short movement test is [X, Y, Z, ${\theta}_X$, ${\theta}_Y$, ${\theta}_Z$]${\leq}$ [${\pm}200nm$, ${\pm}200nm$, ${\pm}250nm$, ${\pm}3urad$, ${\pm}2urad$, ${\pm}1urad$]The errors of long stroke movement test is [X, Y, Z, ${\theta}_X$, ${\theta}_Y$, ${\theta}_Z$]${\leq}$ [${\pm}200nm$, ${\pm}200nm$, ${\pm}250nm$, ${\pm}1.5urad$, ${\pm}2urad$, ${\pm}0.5urad$].

• Proceedings of the KIEE Conference
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• summer
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• pp.992-994
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• 2004

In this paper, hybrid electromagnets using NdFeB permenant magnet are designed by 3-dimensional finite element analysis. Four hybrid magnets levitate the carrier of which total weight including control circuits and battery is 14[kg]. The nominal air gap length of the hybrid magnet is 3[mm]. The control circuit consists of DSP, 4-quadrant chopper, and gap sensor as feedback sensors. As a result, some experimental results for the magnetic levitation control by PI feedback control theory are shown.