• KIPE Magazine
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• v.26 no.3
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• pp.53-59
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• 2021

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.3
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• pp.258-266
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• 2007

When the magnetic levitation system(MAGLEV) initially rise, The MAGLEV has a weak point that is very large variation of the electric current. In this paper, The author applied the multi-loop-control to stably control the magnetic levitation system(MAGLEV). The gains of the control algorithm were selected based on pole locations formulated from a prototype Bessel transfer function model. The design incorporate tradeoffs in DC-to-DC converter hard-ware para-meters and pole locations. In order to confirm the superiority of the proposed pole selection md controller, MATLAB simulation and experiment results are presented.

• 전기의세계
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• v.42 no.12
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• pp.24-33
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• 1993

1. LSHM은 제어성, 효율, 힘/중량면에서 매우 우수하고, LIM은 제어성과 신뢰성면, LSHM에 비하여 기술의 단순성에 의한 가공비와 유지보수비가 저렴한 측면에서 유리하다. 2. 효율면에서는 LHSM이 LIM이 보다 유리하지만 리니어모우터의 재작비와 특랙의 제작면에서는 LSRM이 유리하고, 리니어모우터의 자체중량이나, 트랙의 필요한 철의 중량면에서는 LIM이 유리하다. 3. LIM에비해 LSHM이 추진/부상이 동시에 발생할 수 있도록 수직력이 크게 발생하며, 효율과 역율이 매우좋다. 4. 가장 선두로 개발하고 있는 독일과 일본의 기술개발 연혁을 검토해 보면 공통점은 초기에는 유도형 LIM으로 시작하였다가 나중에는 동기형인 LIM으로 추진시스템으로 전환하였다.

• Proceedings of the KIEE Conference
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• summer
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• pp.1340-1342
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• 2004

근래에 DSP설계기술은 하루가 다르게 성장 해가고 있다. 기존에 많은 양의 소수점 연산이 필요한 기기에 자주 사용되어왔던 TMS320C3x DSP시리즈는 소수점연산에는 유리하지만 DSP를 사용하기 위해 외부메모리 및 A/D컨버터, PWM제너레이터, 엔코더 카운팅 회로 등 주변회로를 설계하는데 많은 시간과 비용이 소비되었다. TMS320LF2407은 기존에 사용하던 복잡한 주변회로가 모두 하나의 컨트롤러에 내장되어 있어 사용하기가 편리하며 고속의 연산능력이 있다. 본 논문에서는 자기부상시스템을 모델링하고 이산시간에서 처리 가능한 다이나믹필터와 상태궤환제어기를 설계한 뒤 DSP를 이용한 부상실험셋트를 구성하여 실험을 통해 DSP의 효용성을 검증하고자 한다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.295-303
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• 2009

The purpose of present study is to examine the effect of guideway characteristics on runnability of low and medium speed maglev vehicle. Dynamic governing equation for 2-dof vehicle and optimal feedback control scheme are developed. And then the effect of vehicle speed, rail roughness, guideway deflection, continuity of spans, each span length on dynamic response of the UTM-01 maglev vehicle are investigated. From the numerical simulation, it is found that the gap between bogie and guideway does not increase greatly within design velocity of the vehicle. The response of vehicle are mostly affected by the guideway deflection rather than rail roughness. As a result of the present study, the runnability of maglev vehicle can be improved by reducing the maximum deflection of guideway and adopting the continuous girder systems.

• Digital Contents
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• no.10 s.65
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• pp.23-34
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• 1998

IMF 시대로 접어들면서 금융권의 위험관리시스템이 국가적인 차원에서 중요한 이슈로 부각되고 있다. 지난해 12월 OECD는 가입국가들에게 위험 관리를 도입해야 한다는 조항을 발표하였고 얼마전 BIS 자기자본 비율 8%를 맞추기 위한 금융권 경영개선안에도 위험관리시스템 구축 조항이 포함되어 있었다. 이처럼 위험관리시스템은 은행권 생존을 위한 필수불가결한 지원 도구로 자리잡고 있다. 금융환경의 변화추이, 위험관리의 현황, 그리고 업체별 전략에 대해 살펴봤다.

• Journal of Advanced Marine Engineering and Technology
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• v.19 no.3
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• pp.84-90
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• 1995

The magnetic levitation system has great advantages, such as little friction, no lubrication no noise and so on. The magnetic levitation system need a stabilizing controller because it is a unstable system in natural. This paper presents the robust stabilizing controller design of the magnetic levitation system. The controller which is designed in this paper by $H_{infty}$ control theory is robust servo controller which has zero offset in spite of the model uncertainties. The validity of controller was investigater through the response simulation. In the future, we will use the result of this study at the actual magnetic levitation system.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.38-46
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• 2002

A new semi-continuous sliding mode control is proposed for electromagnetic suspension systems. The control input is derived from the reaching law and the Lyapunov stability criteria, which is composed of continuous terms and low switching term. It has a low switching gain and chattering fee characteristics. It is shown by the computer simulation that the proposed control has good tracking performance and robustness compared with the classical sliding mode control.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.9
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• pp.2312-2321
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• 1994

In this work the dynamics of an electromagnetic levitation system is described by a set of three first order nonlinear ordinary differential equations. The objective is to design a digital linear controller which takes the inherent instability of the uncontrolled system and the disturbing force into consideration. The controller is made by employing digital linear quadratic(LQ) design methodology and the unknown state variables are estimated by the kalman filter. The state estimation is performed using not only an air gap sensor but also both an air gap sensor and a piezoelectric accelerometer. The design scheme resulted in a digital linear controller having good stability and performance robustness in spite of various modelling errors. In case of using both a gap sensor and an accelerometer for the state estimation, the control input was rather stable than that in a system with gap sensor only and the controller dealt with the disturbing force more effectively.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.3
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• pp.144-153
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• 1996

The magnetic levitation system has many advantages, such as little friction, no lubrication, no noise and so on. For this reason, the magnetic levitation system is utilized in the magnetic bearing of high-speed rotor. The method to obtain magnetic force is both the repulsive suspension method and the attraction suspension method need a stabilizing controller because it is a unstable system in natural. This paper presents the design of robust stabilizing servo controller in spite of being the model uncertainties in the magnetic levitation system by $\textit{H}_{\infty}$ control theory using the free parameter. And we investigated the validity of a designed controller through results of the simulation and the actual experiment.