• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.1
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• pp.40-47
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• 2002

This paper describes a re-adhesion control method for the Korean High-Speed Train (KHST) with parallel induction motor drive. To keep a traction efficiency and to improve vehicle maintenance, the adhesion characteristics between wheel and rail are analyzed. Also the re-adhesion controller is designed as the subsystem of induction motor vector control. In order to verify performance of the proposed control techniques, the simulation is executed by train model and a downscaled re-adhesion control simulator is utilized. Both simulation and running test results show that good re-adhesion characteristics are obtained.

• Transactions of Materials Processing
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• v.24 no.4
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• pp.248-255
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• 2015

The warm drawing of magnesium alloy AZ31B sheet is affected by temperature because tensile elongation is changed due to the elevated temperature. In the current study, the effect of temperature was investigated for an automotive dash panel part by both experimental and FE analysis. Tensile tests were performed to obtain mechanical properties for various temperatures. AZ31B alloy sheet shows increased total elongation with increasing deformation temperature in the range of 200 to 300℃. The heating channel inserted into the die was used to regulate and to obtain an optimal temperature. A temperature controller was constructed to reduce temperature variation. Warm drawing of magnesium alloy AZ31B was performed to produce the desired shape of the lightweight automotive dash panel. The simulated results showed good agreement with the experimental results.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.795-798
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• 1991

The hybrid positon/force control is required when two or more robots perform a coorperative task in a uncertain environment, or when single robot does a task with a constant force to the environment. In this paper, a new control algorithm which control simultaneously the position and the force are proposed, however, especially the conventional position controller employed in the present robot control is used. Moreover, in order to improve the output response characteristics of the system, the PI gains which were computed from the PI gain tunning techniques, are varied based on the results of the Fuzzy algorithm.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.806-807
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• 2011

This paper presents a new sensorless controller used with both the classical sliding mode observer(SMO) and the rate of current change in order to a reduced torque ripple for switched reluctance motor (SRM) sensorless drives. The new sensorless scheme consists of a sliding mode observer (SMO)-based position sensorless approach for high speeds along with a low-resolution discrete the rate of current change for low speeds and standstill. The new position estimation resets between the SMO and the low-resolution of current change according to the speed sign and the position error difference between the SMO and the low-resolution rate of current change. The simulation results show the robustness of this new high performance sensorless control approach with the hybrid sensorless control topology.

• Journal of Power Electronics
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• v.11 no.2
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• pp.113-119
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• 2011

This paper presents a DSP based direct digital control design and implementation for a high power boost converter. A single loop and dual loop voltage control are digitally implemented and compared. The real time workshop (RTW) is used for automatic real-time code generation. Experimental results of a 20 kW boost converter based on the TMS320F2808 DSP during reference voltage changes, input voltage changes, and load disturbances are presented. The results show that the dual loop control achieves better steady state and transient performance than the single loop control. In addition, the experimental results validate the effectiveness of using the RTW for automatic code generation to speed up the system implementation.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.46-47
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• 2011

하이브리드 발전시스템에서 전압과 주파수제어는 서로 다른 분산전원의 동기화 및 전력제어에 있어서 매우 중요하다. 본 논문에서는 디젤발전 시스템에서 여자기 제어기에 대한 제어알고리즘에 관한 것이며, 이는 기본 제어기 알고리즘에 여자기전류에 대한 전류 지령치를 첨가함으로서 제어기의 속응성 및 안정도를 개선할 수 있도록 하였다.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.66-67
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• 2011

하이브리드 발전 시스템에서 전압과 주파수제어는 서로 다른 분산전원의 동기화 및 전력제어에 있어 매우 중요하다. 본 논문에서는 하이브리드 시스템 디젤 발전기의 연료 분사량을 조절하는 액추에이터의 전류제어를 위한 디지털 Governor의 제어 알고리즘을 구현하고, 제어기 개발을 통해 부하 가변 시에도 안정된 주파수 값을 얻어내어, 발전기의 운전영역에서 안정된 속도제어가 이루어지는 가를 시뮬레이션을 통해 검증하였다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.3
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• pp.32-37
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• 2005

Several types of smart materials and control scheme are available to adjust the structure actively in various external disturbances. A control scheme was introduced for a specific material. But the effectiveness of the control scheme has some limitation according to the choice of the smart materials and the response of the structure. The ER(Electrorheological) fluid is adequate for a large control force, and the PZT(lead zirconate titanate) patches are suitable for small but arbitrary control force at any point of the structure. It can be used for active control of structure by changing the dynamic characteristics of the structure. But it has some difficulty in suppressing the excited vibration in broad band. To compensate this resonance of the controlled structure, a hybrid controller was constructed using PPF(Positive position feedback) control with PZT and ER fluid control.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.153-163
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• 1999

본 연구에서는 격자패널을 통한 소음전달을 감소시키기 위하여 외부 구조적 가진으로부터 유발된 경량 패널의 진동을 능동 제어하는 기법을 기술한다. 최적 되먹임제어기와 적응 앞먹임제어기가 결합된 혼합형 제어기가 진동제어기로 사용된다. 되먹임제어기는 주파수 영역의 모델규명법에 의해 추출된 다중 입/출력 패널진동계 모델에 대하여 LQG 최적기법을 이용하여 감쇠능을 향상시키도록 설계된다. 앞먹임제어기는 되먹임 궤환의 결합효과를 자동적으로 보정할 수 있는 제안된 학습법칙에 기초하여 패널의 잔류진동이 최소가 되도록 적응된다. 45.7${\times}$45.7${\times}$2.54 ${cm^3}$ 벌집형상의 고강도 패널, 4개의 관성형 구동기 및 이산신호처리장치에 의해 구현된 패널 진동계에 대한 능동제어 실험을 수행해 본 결과 600Hz 주파수대역에 대한 12dB 진동저감이 이루어 질 수 있었다.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.182-186
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• 2007

This paper studied performance characteristics of hybrid automotive to replace existing fossil fuel vehicles. Specially, about power split type HEV that is T-HEV's drive system when a vehicle drives at steady speed, monitored both output of each engine, motor and generator and battery SOC (state of charge) and analyzed performance characteristic of power transmission system and electricity power parts. This study shows those that acquired and analyzed information from signals between HCU and each controller of actual T- vehicle. From this study, it is confirmed that each conditions of EV and HEV drive can be a improvement with respect to the fuel efficiency of vehicles.