• 제어로봇시스템학회논문지
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• 제20권4호
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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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권7호
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• pp.1274-1292
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• 2011

Due to the variety of household electric devices and different power consumption habits of consumers at present, general home energy management (HEM) systems suffer from the lack of dynamic identification of various household appliances and a unidirectional information display. This study presented a set of intelligent interconnection network systems for electric appliances, which can measure the power consumption of household appliances through a current sensing device based on OSGi platform. The system establishes the characteristics and categories of related electric appliances, and searches the corresponding cluster data and eliminates noise for recognition functionality and error detection mechanism of electric appliances by applying the clustering algorithm. The system also integrates household appliance control network services so as to control them according to users' power consumption plans or through mobile devices, thus realizing a bidirectional monitoring service. When the system detects an abnormal operating state, it can automatically shut off electric appliances to avoid accidents. In practical tests, the system reached a recognition rate of 95%, and could successfully control general household appliances through the ZigBee network.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1091-1096
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• 2007

This paper describes the development of a small lens molding system for manufacturing the small lens like lens of a cellular phone, a small digital camera and so on. In order to manufacture a small lens, firstly, the raw material for lens with spherical shape should be manufactured by processing a glass, secondly, the mold inserted the raw material for lens should be heated till its molding temperature in the electric furnace, finally, the small lens is manufactured by applying the force using pressuring control system. In this paper, the small lens molding system with the function of force control and velocity control was developed. It is composed of a electric furnace and its temperature control system, a pressuring control system, a body, and so on. The temperature characteristic test of the electric furnace, and the force and velocity characteristic test of the pressuring control system were carried out. It was confirmed that the developed system had good functions for manufacturing a small lens.

• 한국정밀공학회지
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• 제25권2호
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• pp.57-64
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• 2008

This paper describes the development of a small lens molding system for manufacturing the small lens like lens of a cellular phone, a small digital camera and so on. In order to manufacture a small lens, firstly, the raw material for lens with spherical shape should be manufactured by processing a glass material, secondly, the mold inserted the raw material for lens should be heated till its molding temperature in the electric furnace, finally, the small lens is manufactured by applying the force using pressuring control system. In this paper, the small lens molding system with the function of force control and velocity control was developed. It is composed of an electric furnace and its temperature control system, a pressuring control system, a body, and so on. The temperature characteristic test of the electric furnace, the force and velocity characteristic test of the pressuring control system were carried out. It was confirmed that the developed system had good functions for manufacturing a small lens.

• 한국군사과학기술학회지
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• 제15권4호
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• pp.366-373
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• 2012

In this paper, serious changes in the electromagnetic environment with increasing power and energy capabilities for electric driving and military mission are discussed. Design and control strategies on the Electro-Magnetic Compatibility(EMC) for the series hybrid electric vehicle are proposed to minimize the effects of electromagnetic interferences.

• 전기학회논문지P
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• 제60권3호
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• pp.138-143
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• 2011

Electric locomotive is adapted to high speed driving and mass transportation due to obtaining high traction force. The electric locomotive is operated by motor blocks and traction motors. Train speed is controlled by suppling power from motor blocks to traction motors according to reference speed. Speed control of the electric locomotive is efficient by spending energy between motor blocks and traction motors. Currently, switched reluctance motors have been studied because the efficient is higher than induction motors. In this paper, model of the switched reluctance motor is presented and the PID controller is applied to the model for the speed control by using Simulink. Asymmetry converter is used for real-time control and system performance is demonstrated by simulating the speed of switched reluctance motor including PID controller.

• 전기학회논문지
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• 제59권12호
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• pp.2125-2130
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• 2010

The neutral section on electric railway system is significant sector in order to prevent short circuit of two electric powers. However, while electric trains pass the neutral section, those speed is decreased and the accident of AC electric traction system and the electric train would be occurred. So the countermeasures are urgently needed. The automatic power switching technology system that is current being research and development is system to improve these problems. Because main object of this system is power change using static switch in the neutral section, it's expected to cause a variety of transients. Especially, onboard transformer inrush current for electric railway train can be occurred more than rated current according to switching time. Therefore, the analysis and improvement are needed to ensure the stability of this system. In this paper, we analyze the operating characteristics of the automatic power switching technology system. Especially, it reviews inrush current according to the closing phase angle. And we propose control plan of inrush current considering the case that voltage is maintained due to counter electromotive force and regenerative braking operation of electric railway train. Finally, the proposed control scheme was reviewed using the transient analysis program.

• 한국정밀공학회지
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• 제18권4호
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• pp.167-175
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• 2001

This paper presents design of active roll controller of a vehicle and experimental study using the electric actuating roll control system. Firstly, parameter sensitivity analysis is performed based on 3DOF linear vehicle model. The controller is designed in the frame work of gain-scheduled H$\infty$ control scheme considering the varying parameters induced by laden and running vehicle condition. In order to investigate a feasibility of an active control system, experimental work is performed using hardware-in-the -loop setup which has been constructed by the devised electric actuating system and the full vehicle model with tire characteristics. The performance is evaluated by experiment using hardware-in-the -loop simulation under the conditions of some steer maneuvers and parameter variations.

• 제어로봇시스템학회논문지
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• 제13권9호
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• pp.861-867
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• 2007

A spreader pose control system using dual-electric compasses has been implemented by measuring the skew angle of the spreader with dual-electric compasses. In the conventional spreader pose measurement, CCD cameras, laser sensors or tilt sensors are mostly used. However those sensors are not only sensitive to the weather and disturbances but also expensive to build the system. To overcome the shortcomings, an inexpensive and efficient system to control the spreader pose has been implemented using the dual-magnetic compasses. Since the spreader iron-structures are noise sources to the magnetic compass, it is not considered to use the magnetic compass to measure the orientation of the spreader. An algorithm to eliminate the interferences of metal structures to the dual compasses has been developed in this paper. The 10:1 reduction model of a spreader control system is implemented and the control performance is demonstrated to show the effectiveness of the dual-magnetic compasses proposed in this research.

• 한국자동차공학회논문집
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• 제8권1호
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• pp.63-71
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• 2000

A shift control algorithm of a newly developed two-speed gear shift system is proposed for electric vehicle applications. The algorithm is formulated according to the motor torque map and optimized to obtain the adequate propulsion characteristics for vehicle. Two speed gear system with shift control algorithm has proved greater efficiencies in terms of energy economy with its simplified hardware and software structures. The gear shifting is designed to be carried out by an actuator and the control signal from a vehicle control unit equipped with $\mu$-processor. The results of performances and efficiency of the algorithm by simulation and vehicle test are described.