• Journal of ILASS-Korea
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• v.22 no.2
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• pp.47-54
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• 2017

$CO_2$ emission regulation will be prescribed and main issue in automotive industry. Mostly, vehicle's fuel efficiency deeply related to $CO_2$ emission is regulated by qualified driving test cycle by using chassis dynamometer and exhaust gas analyser. But, real driving fuel consumption rate depends so much on the individual usage profile and where it is being driven: city traffic, road conditions. In this study, vehicle model of fuel consumption rate for ICEV and PHEV was developed through co-simulation with CRUISE model and Simulink based on driving control model. The simulation results of fuel consumption rate were analysed with on-road vehicle data and compared with its official level.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.552-557
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• 2001

To minimize the fuel consumption in the hybrid vehicle, the single performance index, which can express the fuel consumption in engine and electric energe consumption in battery system at the same time, is required. In this study we proposed a single performance index with equivalent BSFC concept, and with this, we constructed driving control algorithm, which can determine optimal gear ratio and power split ratio of the engine and the motor, for the parallel hybrid vehicle. Additionally, to verify the validity of this algorithm, driving simulation is performed.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.181-185
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• 2006

A study to get better vehicle fuel economy is described based on an express bus. The approach is based on using a commercial software vehicle simulation to identify the relative efficiency of each of the vehicle systems, such as the engine hardware, engine software calibration, transmission, cooling system and ancillary drives. The simulation-based approach offers a detailed understanding of which vehicle systems are underperforming and by how much the vehicle fuel economy can be improved if those systems are brought up to best-in-class performance. In this way, the optimum vehicle fuel economy can be provided to the vehicle customer. A further benefit is that the simulation requires only a minimum of vehicle testing for initial validation, with all subsequent field test cycles performed in software, thereby reducing development time and cost for the manufacturer.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.8
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• pp.773-779
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• 2011

In order to improve fuel economy and emissions, many studies of HEV have been conducted. However, most of these studies concentrate on parallel or power-split HEVs. Series-type HEVs have some advantages over parallel and power-split HEVs. One is that the engine is operated at high efficiency since the engine and the driveshaft are decoupled. Nevertheless, the optimization of the powertrain system of series HEV has not been specifically addressed. We conduct an optimization of the generation system of a series HEV based on the series HEV bus. The main objectives are to simulate the system and to compare the fuel economies of conventional and optimized generation systems.

• Journal of the korean Society of Automotive Engineers
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• v.17 no.2
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• pp.7-13
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• 1995

기관의 저연비화는 비단 경제적인 면뿐 아니라 환경 등 사회적인 면에서 보았을때에도 차량이 갖추어야 할 필수적인 요건이라 할 수 있다. 지금의 추세로는 차량에 희박연소기관을 탑재하는 것은 앞으로 더욱 증가될 것으로 예측된다. 이 저연비에 효과적으로 대응될 수 있는 희박연소는 일반적인 3원촉매를 사용할 경우 지금까지는 배기량 2l를 넘는 대배기량기관에서는 실용화가 어려운 것으로 되어 있어서 희박연소기관 대부분은 1.8l급까지로 되어 있다. 그런데 최근 일본의 미쓰미시사는 별개의 희박연소용 촉매를 사용하지 않으면서 2.5l급의 희박연소화한 대배기량기관을 차량에 탑재하는데 성공한 것으로 발표하고 있다. 더구나 지금까지 대부분의 희박연소기관에 채용되고 있는 전역 공연비센서가 아닌 보통의 $O_{2}$센서이고 이와 같이 큰 배기량기관의 희박연소화를 실현한 것을 세계에서 최초의 것으로 보고하고 있다.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.136-137
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• 2012

본 논문에서는 하이브리드 전기자동차의 전장시스템 에너지 공급을 위한 보조배터리 충전용 저전압 직류 변환장치(Low voltage DC-to-DC Converter, LDC)를 제안한다. 차량 탑재용의 특성상 소형 경량화 설계 기술을 통한 연비증가, 동력성능의 향상이 매우 중요하다. 본 논문에서 제안하는 LDC는 부스트와 포워드 컨버터 구조를 혼합한 형태로 부스트 컨버터의 입력 인덕터를 변압기로 대체하여 포워드 컨버터와 결합시킴으로서 출력전압의 승 강압 동작을 구현한다. 따라서 차량 시동 시 내연기관을 구동하기 위한 승압모드로 동작하고, 그 외 일반적인 경우는 차량 내 각종 전장부하에 전력을 공급하기 위한 강압모드로 동작된다. 제안된 컨버터의 동작 모드에 따른 이론적 분석을 시행하고 PSIM을 이용한 시뮬레이션을 통해 타당성을 검증한다.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.79-80
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• 2016

상용차에서 사용되고 있는 기계식 에어컨 시스템은 엔진의 가동(주행 또는 공회전)에 의해 발생되는 에너지를 이용해 차량 실내온도를 유지시켜준다. 이러한 기계식 에어컨 시스템의 작동은 엔진 구동력의 일부를 사용하기 때문에 상용차의 연비와 큰 관련성 있다. 상용차는 하절기 작업대기, 차량 내 야간취침 등이 빈번해 운전자의 운행습관에 따라 연료 소비량이 증가하는 단점을 가지고 있다. 본 논문에서는 이러한 단점을 개선하고자 대형 상용차량이 정차중인 무시동 기간에도 일정 온도의 유지가 가능 하도록 4kW급 Cascaded 푸쉬-풀 컨버터와 전동식 압축기 구동용 인버터로 구성된 전력변환장치를 제안하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.4
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• pp.371-376
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• 2012

The experimental test was conducted for a heavy-duty DME bus in JE-05 exhaust gas test mode using a chassis dynamometer, exhaust gas analyzers, and a PM measurement system. The heavy-duty DME bus was not equipped with after-treatment systems such as DOC or DPF. The dynamic behavior, emission characteristics, and fuel economy of the bus were investigated with an 8.0-liter, 6-cylinder conventional diesel engine. The results showed that the dynamic behavior in DME mode was almost the same as in diesel mode. However, there was little difference among the two operation modes for $NO_x$ and CO emissions. THC emissions were lower for DME mode than for diesel mode. Also, the amount of PM emissions was remarkably lower than for the diesel mode because DME contains a greater amount of oxygen than diesel. The data showed that $CO_2$ emissions were almost similar in the two modes but fuel economy (calculated using heating value) was lower for DME mode than for diesel mode.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.5 no.6
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• pp.583-591
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• 2015

In order to evaluate the performance of TAS applied to the hybrid vehicle of the soft belt driven, acceleration performance and fuel consumption performance is to be superior to the existing vehicle. The key components of belt driven TAS(Torque Assist System), such as the engine, the motor and the battery, The key components of the driven belt TAS, such as the engine, the motor, and the battery, have a significant impact on fuel consumption performance of the vehicle. Therefore, in order to improve the efficiency at the point of view based on the overall system, the study of the power distribution algorithm for controlling the main source powers is necessary. In this paper, we propose the power distribution algorithm, applied the homogeneous analysis method in terms of fuel equivalent, for minimizing the fuel consumption. We have confirmed that the proposed algorithm is contribute to improving the fuel consumption performance satisfied the constraints considering the vehicle status information and the required power through the control parameters to minimize the fuel consumption of the engine. The optimization process of the proposed driving strategy can reduce the trial and error in the research and development process and monitor the characteristics of the control parameter quickly and accurately. Therefore, it can be utilized as a way to derive the operational strategy to minimize the fuel consumption.

• Journal of Energy Engineering
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• v.5 no.1
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• pp.42-49
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• 1996

Natural gas is one of the promising alternative fuels for automotive vehicles, because it has lower exhaust emissions and better fuel economy characteristics than those of gasoline, and can be used in conventional gasoline engines without major modifications. In the present study, a conventional gasoline engine was modified to a CNG engine, which can be operated with CNG only, and an engine bench test was performed to calibrate the operating parameters of the engine such as air fuel ratio, spark advance, etc. at various operating conditions. The modified CNG engine, then, was installed on a commercial gasoline vehicle and a vehicle driving test on chassis dynamometer was performed to examine the fuel economy and exhaust emission characteristics. As a result, the prototype CNG vehicle showed lower exhaust emissions and better fuel economy characteristics, but slightly reduced brake horse power, compared to the gasoline vehicle.