• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.268-270
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• 1993

The implementation of Nonlinear Feedback Linearization control for Electro-Magnetic Suspension system is presented. The controller using TMS320C31 DSP chip was proposed and the experiments were performed Control law for EMS system using feedback linearization is derived and implemented in the DSP. Some tests were constructed far experimental comparison between feedback linearization and classical state feedback The experimental results demonstrate that the feedback linearization controller shows bettor performance than that of the classical state feedback controller and it is robust with respect to disturbance and parameter variation, though some steady-state errors appear.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.280-283
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• 2000

In this paper, a fault tolerant control problem is considered for a class of nonlinear system formulated in a gain scheduling form with LMI-based H-inf control technique Key benefits of this proposed scheme are demonstrated in the simulation of an electromagnetic suspension system with actuator and/or sensor failures, and the method is compared with the convensional state-feedback and output-feedback controller. It is clearly observed that the proposed control scheme shows an improved output performance in comparision with convensional methods.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1267-1269
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• 2005

This paper presents the design for improving performance of the high-precision Magnetic levitation system. Motor performance on various design schemes such as thickness and magnetizing patterns of the permanent magnets, pole pitch, length of air gap, turn number of windings, and thickness of the aluminum-core has been investigated in detail by using FEM(Finite Element Method) Simulation-based DOE(Design of Experiments) method is also applied in order to reduce the large number of analysis according to each design variable and consider the effect among variables. The design in all aspects is proposed by an optimization algorithm using regression equation derived from the simulation-based DOE.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1113-1125
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• 2008

In this paper we present a RAMS to be applied to the development of the Urban Maglev Train Signalling System. The RAMS that can be applied to the life cycle of a Signalling system, from the basic design to the dismantlement, shows the whole process of the paper work in detail through the establishment of a goal, analysis and assessment, the verification. In this paper we study about the making a plan, the preliminary hazard analysis, the hazard identification and analysis to guarantee the safety of the Signalling System. The process for the verification of the system safety is divided into several steps based on the target system and the approaching method. The guarantee of the system safety and the improvement of the system reliability is followed by the recommendation of the international standards.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.364-371
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• 2008

In general Maglev (magnetically levitated vehicle) has about 4 or 5 bogies per one vehicle to improve stability of electromagnetic suspension and 4 air-spring per one bogie are to be equipped to prevent form excessive yawing and pitching motion of bogie. 3 leveling valve per one vehcile will be applied to control the height of carbody. This kind of vehicle is on the design stage, and design review will be carried out before manufacture. The suspension system of Maglev consists of 16 of air-spring, auxiliray reservoir and orifice, 3 leveling valve, which are different composition comparative to conventional rolling stock. To improve operational reliability of vehicle, additional ventilation valve will be equipped with airspring. This kind of new design concept requires fundamental design review. In this study, suspension systems of Maglev will be built as mathematical model. Then designed suspension system will be reviewed in view of various points through proposed suspension simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.348-353
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• 1994

Magnetic Servo Levitation (MSL) has been proposed as a method to drive a fast-tool servo system. This paper discusses some fundamental control and modeling issues in the development of a long-range high-bandwidth fast-tool servo based on MSL. A resursive linear model is developed to describe the system's dynamics linear model is developed to describe the system's dynamics, and further used to discuss controller design. For a given controller architecture, the performance of two controllers is then compared, one based on an approximation to the inverse plant dynamics, the second based on a adaptive neural network.

• 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.

• 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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.9
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• pp.925-932
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• 2014

If a rotor possesses a high gyroscopic coupling or the running speed is high, the dynamical changes in the rotor become prominent. When active magnetic bearings are used to support such rotors, it is necessary for the bearing controller to take these dynamical changes into consideration. Independent-axis controllers, which are the most commonly used, modulate the bearing force solely based on the sensor output of the same axis. However, this type of controller has difficulties in overcoming the dynamical changes. On the other hand, mixed-axis controllers transform the sensor output into components corresponding to the vibrational modes. A separate controller can then be designed for each vibrational mode. In this way, the controller can be designed based on the dynamics of the rotor. In this paper, we describe a design process for a mixed-axis controller that uses a detailed mathematical model of the system. The performance of the controller is evaluated based on the ISO sensitivity requirements and unbalance response, while considering the change in the system dynamics due to the running speed.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.700-703
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• 1997

A robust controller for a 6 DOF magnetically levitated fine manipulator is presented. The proposed controller consists of following two parts : a model reference controller (MRC) and a H$_{\infty}$ controller (HIC). First, the MRC stabilizes the motion of the manipulator. Then, the motion of the manipulator follows that of the reference model. Second, the HIC minimizes errors generated from the MRC due to noise and disturbance since the HIC is a kind of robust controller. The experiments of position control and tracking control are carried out by use of the proposed controller under the conditions of free disturbances and forced disturbances. Also, the experiments using PID controller are carried out under the same conditions. The results from above two controllers are compared to investigate the control performances. As the results, it is observed that the proposed controller has similar position accuracy but better tracking performances comparing to the PID controller as well as good disturbance rejection effect due to the robust characteristics of the controller. In conclusion, it is verified that the proposed controller has the simple control structure, the good tracking performances and good disturbance rejection effect due to the robust characteristics of the controller..