• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.213.1-213.1
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• 2008

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.792-796
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• 2006

In recent years, the semiconductor industry and the optical industry is developed rapidly. The recent demand has expanded for optical components such as a optical lens, a optical semiconductor and a measuring instrument. Object transport systems are driven typically by the magnetic field and the conveyer belt. Recent industry requires more faster and efficient transport system. However, conventional transport systems are not adequate for transportation of optical elements and semiconductors. Because conveyor belts can damage precision optical elements by the contact force and magnetic systems can destroy the inner structure of semiconductor by the magnetic field. In this paper, the levitation transport system using ultrasonic wave is developed for transporting precision elements without damages. This transport system is using 2-mode ultrasonic wave excitation and flexural beam modes shapes are evaluated. It compared simulation results with experimental results

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.830-836
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• 2006

In this paper described an auto tuning neuro-fuzzy PID controller based neural network. The PID type controller has been widely used in industrial application due to its simply control structure, easy of design, and inexpensive cost. However, control performance of the PID type controller suffers greatly from high uncertainty and nonlinearity of the system, large disturbances and so on. In this paper will design to take advantage of neural network fuzzy theory and pid controller auto toning technique. The value of initial scaling factors of the proposed controller were determined on the basis of the conventional PID controller parameters tuning methods and then they were adjusted by using neural network control techniques. This controller simple structure and computational complexity are less, and also application is easy and performance is excellent in system that is strong and has nonlinearity to system dynamic behaviour change or disturbance. Finally, the proposed auto tuning neuro-fuzzy controller is applied to magnetic levitation. Simulation results demonstrated that the control performance of the proposed controller is better than that of the conventional controller.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.7
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• pp.787-793
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• 1999

A self-sensing magnetic suspension system utilizing a LC resonant circuit is proposed by using the characteristic that the inductance of the magnetic system is varied with respect to the air gap displacement. An external capacitor is added into the electric system to make the levitation system be statically stable system, which much relieves the control effort required to stabilize the magnetic suspension system of haying an intrinsic unstable nature. For the realization of the self- sensing magnetically levitated system, an amplitude modulation / demodulation method is used with a positive position feedback controller Experimental results are presented to validate the proposed method.

• Proceedings of the KIEE Conference
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• summer
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• pp.1076-1078
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• 2004

This paper deals with eddy-current magnetic repulsion system. The passive system employing permanent magnets on the moving part maximizes levitation forces by using Halbach array and conducting plate. We predict force characteristics according to permanent magnet array and conducting bar

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.186.3-186.3
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• 2010

본 논문은 우리나라와 같이 평균풍속이 낮고 바람 방향이 수시로 변하는 지역에 적합한 풍력발전 시스템에 관하여 논한다. 특히, 풍향에 상관없이 효율을 보장하고, 아주 약한 풍속 조건에서도 기동(Cut-in)되며, 낮은 평균풍속 5~6m/s인 지역에서도 경제적으로 풍력발전 단지의 구축이 가능하며, 다양한 지역에 설치가 가능하고, 소음이 적고 친(親) 환경적이며, 양산이 가능해 납기를 예측할 수 있으며 그리고 모든 부품 및 시스템의 국산화가 가능해야 한다는 7가지 조건을 만족하는 풍력발전시스템으로 이를 실현시키기 위하여 현재 풍력발전시스템의 가장 앞선 요소기술(state-of-the-art technology)인 직접구동 방식, 적층식, STR 블레이드, AFPM동기발전기, 자기부상 및 전자브레이크 등 5가지 기술을 복합 융합하여 최고의 효율 및 성능을 보장해 주는 적층 연곡형 시스템이다.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.626-629
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• 1997

The urban transit propelled by single sided linear induction motor(SLIM) have been in stage for practical application. Also, the use of the linear induction motor in traction systems enables large forces to be achieved without friction between wheels and rails. In this paper we discuss the linear induction motor (LIM) drive system (300KVA) for magnetic levitation vehicles.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.1
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• pp.22-30
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• 2001

This paper describes a neural network based fuzzy PID control scheme. The PID controller is being widely used in industrial applications. However, it is difficult to determine the appropriated PID gains in nonlinear systems and systems with long time delay and so on. In this paper, we re-analyzed the fuzzy controller as conventional PID controller structure, and proposed a neural network based self tuning fuzzy PID controller of which output gains were adjusted automatically. The tuning parameters of the proposed controller were determined on the basis of the conventional PID controller parameters tuning methods. Then they were adjusted by using proposed neural network learning algorithm. Proposed controller was simple in structure and computational burden was small so that on-line adaptation was easy to apply to. The experiment on the magnetic levitation system, which is known to be heavily nonlinear, showed the proposed controller's excellent performance.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.2
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• pp.102-109
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• 2000

The magnetically levitated system technology is highly expected to contribute the new transportation system of the 21st century with its high velocity operation, better riding comforts, friendliness to environment and saving of maintenance labour. Its development has been completed in low speed and in high speed application. In 2005, the Transrapid with 430 km/h speed will go into operation between Berlin and Hamburg[1]. In the year 2000, the realization of JR-Maglev will be basically evaluated for commercial operation[2]. In korea, maglev test vehicle with magnet for levitation and single sided linear induction motor for propulsion is under test at 1 [km] test track in KIMM.[3,4] Here, a transverse flux linear motor in combination with the levitation and the guidance leads to a considerable high power density and high efficiency simultaneously. The designed and measured performance of transverse flux linear motor for maglev system revealed a great potential of system mass reduction.

• 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.