• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1451-1456
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• 2013

This paper presents the improved zero power levitation control algorithm for a quadruple hybrid EMS (Electromagnetic Suspension) system. Quadruple hybrid EMS system is a united form of four hybrid EMS systems one on each corner coupled with a metal plate. Technical issue in controlling a quadruple hybrid EMS system is the permanent magnet's equilibrium point deviation caused by design tolerance which eventually leads to a limited zero power levitation control that only satisfies the zero power levitation in one or two hybrid EMS system among the four hybrid EMS system. In order to satisfy a complete zero power levitation control of the quadruple hybrid EMS system, the proposed method presented in this paper adds a compensating algorithm which adjusts the gap reference of each individual axe. Later, this paper proves the stability and effectiveness of the proposed control algorithm via experiment and disturbance test.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.4
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• pp.395-401
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• 2014

Magnetic levitation systems using the attraction force of electromagnets have many constraints according to the variation of air gap and the nonlinearity of electromagnetic force and inductances. As a result of these constraints, the nonlinear control of a magnetic levitation system has been improved by the latest advanced processors and accurate measurement system which can overcome problems such as many constraints and nonlinearity. This paper concentrates on the modeling of a nonlinear magnetic levitation system and an application of an exponential reaching law based sliding mode controller using the exponential reaching law which is one of the most robust controllers against external unexpected disturbances or parameter fluctuations. Controllability of a magnetic levitation system using the sliding mode control algorithm and robustness against parameter fluctuations have been verified through the experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1082-1087
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• 2003

In this paper, we address the development of magnetic levitation positioning system. This planar magnetic levitator employs four permanent magnet liner motors. Each motor generates vertical force for suspension against gravity, as well as horizontal force for drive levitation object called a platen This stage can generate six degrees of freedom motion by the vertical and horizontal force. We derived the mechanical dynamics equation using lagrangian method and used coenergy to express an electromagnetic force. We proposed control algorithm for the position and posture control from its initial value to its desired value using sliding mode control. Some simulation result is provided to verify the effectiveness of the proposed control scheme.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.355-359
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• 1992

This paper presents a procedure to design a real time control system for a magnetic levitation system based on the state space approach by adopting a control method compensating attractive force according to load variation of maglev vehicle. Also the paper has realized a robust control algorithm for the change of self-inductance parameters and the disturbance such as the change of mass of Maglev vehicles. The theoretical results are applied to the gap control problems of an attractive-type-magnetic levitation system and the effectiveness is proved by the implementation of digital control using 16 bits microcomputer.

• 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.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.37.6-37
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• 2001

In this paper, a robust levitation controller for an attractive MAGLVE system is designed. The design of an H$\infty$ controller based on LMI method is proposed for the control of a simple magnetic levitation system. Attractive MAGLEV system is highly nonlinear and open-loop unstable, and has a very restricted equilibrium region, Also, this system has to tolerate various disturbances caused by propulsion. Thus a robust feedback controller is needed to control the system efficiently. We first formulate a mathematical model for the single magnet levitation system. Then we set up an H$\infty$ control problem as a mixed sensitivity problem where the augmented plant is constructed with frequency weighting function ...

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.532-538
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• 1992

Control system design for attraction type Maglev system is dealt in this paper. Characteristics of levitation and guidance control is explained and a kind of active guidance controller performance is compared with passive guidance control. Also, a method of using absolute and relative information simultaneously is adopted for levitation control. All the methods studied performed very well in the experiments as well as simulation.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.6
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• pp.906-915
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• 2004

In this paper, we address the development of magnetic levitation positioning system. This planar magnetic levitator employs four permanent magnet liner motors. Each motor generates vertical force for suspension against gravity, as well as horizontal force for driving levitation object called a platen. This stage can generate six degrees of freedom motion by the vertical and horizontal force. We derived the mechanical dynamics equation using Lagrangian method and used coenergy to express an electromagnetic force. We proposed a control algorithm for the position and posture control from its initial value to its desired value using sliding mode control. Some simulation results are provided to verify the effectiveness of the proposed control scheme.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.10
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• pp.165-171
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• 1998

An axial electromagnetic levitation system using attractive force is a highly nonlinear system due to the nonlinearity of materials, variable air gap and flux density. To control the levitating system with large air gap, a conventional PID control based on the linear model is not satisfactory to obtain the desired performance and the position tracking control of the sinusoidal motion by simulation results. Thus, sliding mode control(SMC) based on the input-output linearization is suggested and evaluated by simulation and experimental approaches. Usefulness of the SMC to this system is conformed experimentally. If the expected variation of added mass can be included in the gain conditions and the model, the position control performance of the electromagnetic levitation system with large air gap will be improved with robustness.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3079-3085
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• 2011

Through Korean Urban Maglev Program started in 2006, an urban maglev train was developed and the demonstration line is under construction as of now in 2011. The target speed of the developed maglev train is 110km/h, and the core technologies for super speed maglev trains over 500km/h are being studied. The propulsion and levitation systems of the super speed maglev train under consideration consist of linear synchronous motors (LSM) and levitation electromagnets which also act as a mover of LSM. In addition, guidance electromagnets are used to ensure stable running on curved tracks during super speed operation. The levitation and guidance control is focused on in this paper. For experimental purpose, a small maglev train is being manufactured, and its levitation and guidance controller is studied. The main task of the controller is to maintain the gap between the corresponding electromagnet and the guideway constantly. In general, measurements of the gap, acceleration and current and so on are utilized, and the gap control is implemented independently for each electromagnet. In this paper, the levitation and guidance system is modelled considering mechanical interactions, and the levitation and guidance controller is proposed based on this model. The developed controller is verified by various simulations using MATLAB/Simulink.