• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1398-1402
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• 2007

In a high speed train, OBCS(On-Board Computer System) is a up-to-date computer control system that provide controlling, monitoring, maintaining and reparing of the important device, supporting a driver, status of a train, service maintenance, managing the remote control mode, driving order & control, control of a electrical or pneumatic circuit and a passenger service. In general, OBCS is located in each car but in a power car, both main and auxiliary computers are used. These avoid a network collision and maintain the independence of condition and failure records with the information of line number, train number and car number. This paper is intended to provide the information about the identification coding method of domestic and foreign OBCS, for the new high speed train (KTX-II).

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.938-943
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• 1998

The induction motor of the electric vehicles is controlled based on the vector control method to obtain good torque control characteristics. In the conventional vector control system, the field exciting current should be kept on a constant value to keep a stable flux level. This method has a liability that core loss becomes increasing at the light load region. To solve this liability, the efficiency maximizing control method of the vector controlled induction motor is proposed in thid paper. We developed light weight water cooled 60kW induction motor drive system which adopts our method and fabricated a conversion electric car for actual vehicle test. We demonstrate the usefulness of drive system by comparing its driving mode with conventional field oriented system and an efficiency maximizing controlled induction motor.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.288-294
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• 2001

In this study, a new PWM method considering the actuation delay of high speed solenoid valves is proposed to improve the response characteristics of electro hydraulic servo systems controlled by high speed solenoid valves. In addition, the decision method for the system gain, the basic period of PWM, and the sampling time is proposed, Since the conventional system controlled by high speed solenoid valves is too slow to apply this method, a high speed driving circuit(Quick-Drive) which enables rapid switching of the high speed solenoid valve at a high speed sampling mode is applied to realize this method. The experimental result shows that it is possible to achieve precision and quiet control without occurrence of limit cycle and wide range dead band.

• Journal of ILASS-Korea
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• v.20 no.1
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• pp.28-34
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• 2015

Recently, some researchers have been carried out risk assessment of vehicles exhaust on human health. Especially, some of VOCs which is non-controlled, was classified to hazardous pollutant, such as 1,3-Butadiene and BTEX(Benzene, Toluene, Ethylbenzene and Xylene). Therefore, the profile on non-controlled pollutant may be needed in the future, because it would be critical data or information to control them. Additionally, with increasing amount of motorcycle, the source profiling is essential for estimating emission factor and amount on motorcycle exhaust. For these, in this study, imported motorcycles (8 vehicles) were selected as a test model while considering the increasing ratio on sales volume between 2013 and 2014; it was also compared with domestic motorcycles on those. The experiment was conducted by driving mode, UDC and ECE+EUDC that made from EURO III. In addition, it was performed at cold start driving mode without effect by displacement, for evaluating only correlation of BTEX with HC. In order to apply the ratio (m,p-Xylene/o-Xylene) as a marker, the ratio was compared with those of tunnel, road side and residential area. As a result, it showed best correlation ($R^2=0.98$) among those. In the future, it has to be considered as a marker for effect evaluation to atmospheric environment by exhaust emission.

• Journal of the Optical Society of Korea
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• v.14 no.2
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• pp.137-141
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• 2010

We report, for the first time to our knowledge, observation of polarization bistability from 1.55-${\mu}m$ wavelength single-mode VCSELs of a conventional cylinder-shape under control of their driving current, and demonstration of all-optical flip-flop (AOFF) operations based on the bistability with optical set and reset pulse injection at a 50 MHz switching frequency. The injection pulse energy was less than 14 fJ. The average on-off contrast ratio of the flip-flopped signals was about 7 dB. These properties of the VCSELs will be potentially useful for future high-speed all-optical signal processing applications.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.2
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• pp.175-180
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• 2017

The measurement of three-phase current is important to control the instantaneous torque of a interior permanent magnet synchronous motor(IPMSM) using a three-phase inverter. Therefore, shunt resistors are used in low-cost motor-driving systems to measure three-phase current instead of additional current sensors that are too expensive for these systems. However, in certain regions of a space vector plane, shunt resistors cannot reconstruct three-phase current in high-speed driving mode. In this paper, predictive current control is used to compensate for the three-phase current in those regions, which results in a reduction of current ripple in a three-shunt sensing inverter(TSSI) and torque ripple in IPMSM.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.157-165
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• 2000

A small hydraulic winch system with an automatic tension control unit was designed to improve the work efficiency of coastal small vessels and the dynamic response characteristics of the winch system operated in the open loop condition was investigated. The inlet and the outlet pressures in hydraulic motor, the torque and the rotating speed of winch drum were measured as a function of time, and the behaviour in autotension mode for stepped load changes was analyzed. The results obtained are summarized as follows : 1. The developed winch system for coastal small vessels will result in better fishing with improved efficiency and lower manpower consumption by remote control of winch system. 2. The rotating delay times of winch drum for on/off operations of solenoid valve were 0.09 see at CW mode and 0.04 sec at CCW mode, respectively. After the solenoid valve was controlled, response characteristics were unstable slightly but showed good tracking behaviour over short time. 3. The driving torque of winch system in autotension mode was kept almost constant of 55.9 kgf·m, and 11.1 then the rotating speed of winch drum was kept almost constant of 5.1 rpm in the larger torque than 55.9 kgf·m and 11.1 rpm in the lower torque than that. 4. The 5% settling times in the transient response characteristics of autotension mode under rapid increasing and decreasing conditions of load were 0.12 sec and 0.2 sec, respectively, and then the rotating speeds were 11 rpm and 5.3 rpm, respectively. 5. The tracking behaviour of torque and rotating speed by remote control operation were stable within 0.23 sec at CW mode and 0.37 sec at CCW mode, respectively.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.5
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• pp.457-466
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• 2004

In this paper, a modified converter is presented and analyzed to use as a photovoltaic converter. And also a new parallel driving scheme is proposed to increase output power and to reduce the output voltage ripple. The ratio of the output to the input voltage of the modified converter is equal to that of the boost converter. The difference between both converters is the composition of output terminal. Owing to the discrepancy, a working voltage of the output capacitor of the modified converter becomes lower, thus the capacitance value of the capacitor can be smaller than that of the boost converter. The proposed parallel driving is based on the modified converter and a current-mode-control method. It gives a good solution for alleviating the current sharing unbalance problem of conventional parallel operations. It reduces the output voltage ripple by means of increasing the equivalent switching frequency without additional switching losses. The validity of the proposed parallel driving strategy is verified through computer-aided simulations and experimental results.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.348-351
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• 2001

In this paper, voltage-fed high frequency resonant inverter of instantaneous current phaser control method used to DC voltage source separated is proposed. In the output control method, a novel circuit type of phase shift driving signal method with CVCF illustrated, also the operation principle of the proposed circuit is described in detail and its characteristics are presented as to normalized parameters. According to the each mode, in order to the circuit analysis and characteristic evaluation of the state equation are derives and present used to normalized parameter. In the future, this proposed inverter show that it can be practically used as power source system for the lighting equipment of discharge lamp, DC-DC converter etc.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.3
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• pp.253-259
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• 2014

This study proposes a map-based control method to improve a vehicle's lateral stability, and the performance of the proposed method is compared with that of the conventional model-referenced control method. Model-referenced control uses the sliding mode method to determine the compensated yaw moment; in contrast, the proposed map-based control uses the compensated yaw moment map acquired by vehicle stability analysis. The vehicle stability region is calculated by a topological method based on the trajectory reversal method. The performances of model-referenced control and map-based control are compared under various road conditions and driving inputs. Model-referenced control uses a control input to satisfy the linear reference model, and it generates unnecessary tire lateral forces that may lead to worse performance than an uncontrolled vehicle with step steering input on a road with low friction coefficient. The simulation results show that map-based control provides better stability than model-referenced control.