• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2352-2354
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• 2000

In this paper, to present a new ignition control system for improvement the fuel economy. An actual hardware was made to prove that new control system, which only some of cylinder using under the idle status or low speed preserving the engine rpm, is applicable to effec fuel economy.

• 한국산학기술학회논문지
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• 제13권2호
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• pp.498-503
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• 2012

엔진 회전속도가 1,500rpm 이상 일 때 차량의 가속 페달을 놓은 경우 인젝터 연료분사가 중지된다. 이것을 연료차단(fuel-cut) 기능이라 부르고, 현대의 대부분의 차량들은 이 기능을 장착하고 있다. 이 기능은 많은 경우 고속도로의 내리막 구간에서 작동된다. 이렇게 연료차단이 발생하는 경우 차량의 $CO_2$ 배출 가스는 '0'이 된다. 서해안 고속도로에서 이 연료 차단 기능을 사용하면 2,000cc 승용차의 $CO_2$ 배출량은 4% 감소한다. 그리고 내리막 구간의 경우 가장 효율적인 운전 패턴을 찾기 위하여 연료차단 기능을 AVL사의 CRUISE 소프트웨어로 시뮬레이션 하였다. 연비향상을 위해서 급격한 내리막 구간일 경우 연료 차단을 위한 차량의 하한 속도를 높게 유지해야 한다는 것을 CRUISE 소프트웨어 시뮬레이션으로 알 수 있었다. 또한 가장 우수한 연비 성능은 내리막 구간 내에서 연료차단과 재가속이 완료되어야 함을 알 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.152-155
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• 2007

Fuel cell electric vehicles (FCEVs) using hydrogen gas are zero emission vehicles, thus emission measurement for combustion vehicles is not applicable. The hydrogen gas consumption for fuel economy will be measured by the stabilized pressure/temperature method, mass flow method and electrical current method, etc. In this research, weight method with a newly manufactured test equipment is applied to measure the hydrogen consumption because above 3-methods have a deviation. The hydrogen consumption is directly calculated by the weight differences of the external hydrogen tank before and after the chassis dynamometer test. Ultimately the fuel economy for FCEVs is obtained with a deviation less than 1% in all chassis dynamometer tests.

• 한국자동차공학회논문집
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• 제7권8호
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• pp.123-131
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• 1999

Natural gas is one of the most promising alternative fuels for automotive vehicles. However, natural gas varies in compositional between the originating fields and may be further modified due to processing and additional mixing. These variations are known to affect engine performance and emissions through changes in fuel metering and combustion characteristics. In the present study, the effect of gas compositions on vehicle performance such as fuel economy, driveability and exhaust emissions was examined. Analysis are made of using 3 types of NGVs which were made by automakers and 6 different fuels which are selected in consideration of the variation in fuel composition on the worldwide market. The results may be utilized to develop natural gas natural gas engine in automaekrs and/or to establish the fuel standard in the refueling stations.

• 자동차안전학회지
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• 제10권3호
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• pp.45-54
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• 2018

Greenhouse gas is the big issue of the whole world. So foreign countries, EU, USA, Japan, China and Korea made the policy for reducing greenhouse gas. For calculation of reduction, it is necessary to know the quantity of current greenhouse emission per year in Korea. It is not reflected real driving condition for measuring the Fuel economy and greenhouse gas. The subject of this study is to figure out the characteristics which influence on greenhouse gas in real driving condition. And final goal is applying the policy greenhouse emission reduction.

• Journal of Mechanical Science and Technology
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• 제17권11호
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• pp.1725-1731
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• 2003

A high level CVT ratio control algorithm is proposed to improve the engine performance by considering the powertrain response lag. In this algorithm, the desired CVT speed ratio is modified from the vehicle velocity, which is estimated after the time delay due to the powertrain response lag. In addition, the acceleration map is constructed to estimate the vehicle acceleration from the throttle pedal position and the CVT ratio. Using the CVT ratio control algorithm and the acceleration map, vehicle performance simulations are performed to evaluate the engine performance and fuel economy. It is found that the fuel economy can be improved about 3.6% for FUDS by the ratio control algorithm for the target vehicle. In selecting the appropriate time delay, compromise between the fuel economy and the acceleration performance is required.

• 한국자동차공학회논문집
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• 제22권1호
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• pp.71-76
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• 2014

This Research focuses on how to maximize fuel economy improvement of I.S.G. while keeping 12V system. With 12V system the maximum gain of fuel economy with I.S.G. is known to be about 3~5% in FTP-75 mode because engine stop is only conducted in standstill idle. But in this study deceleration engine stop (engine speed is zero) has been tried additionally and the optimum condition for deceleration engine stop was found to maximize fuel economy improvement in practical point of view, the result of which is about 8.8% in FTP-75.

• 한국자동차공학회논문집
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• 제24권4호
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• pp.401-407
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• 2016

For high fuel economy, many kinds of unit in vehicle have been developed. In steering system, as a result, HPS(Hydraulic Power Steering) system has been replaced as EHPS and EPS system. But the structures of these systems are totally different, and that causes the uncertainty of fuel economy evaluation. Therefore we undertake to research to find results and tendency of fuel economy and energy in steering system. For accurate evaluation, we modeled different types of steering systems on same vehicle model. The simulation came into action on various driving cycle. The driving condition is designed to show standby power of pump. Results show differences of fuel efficiency and energy consumption.

• 한국수소및신에너지학회논문집
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• 제31권2호
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• pp.250-258
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• 2020

This study was conducted to analyze the impact of low level bio-alcohols that can be applied without modification of vehicles to improve air quality in Korea. The emissions and fuel economy of low level bio-alcohols mixed gasoline fuels of spark ignition vehicles, which are direct injection and port fuel injection, were studied in this paper. As a result of the evaluation, the particle number (PN) was reduced in all evaluation fuels compared to the sub octane gasoline without oxygen, but the correlation with the PN due to the increase in the oxygen content was not clear. In the CVS-75 mode, emitted CO tended to decrease compared to sub octane gasoline, but no significant correlation was found between NMHC, NOx and fuel economy. In addition, it was found that the aldehyde increased in the oxygenated fuel, and there was no difference in terms of the amount of aldehyde generated among a series of bio-alcohol mixed fuels.

• International Journal of Automotive Technology
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• 제8권5호
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• pp.651-658
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• 2007

This paper presents a new type of fuzzy logic-based power control strategy for fuel cell hybrid electric vehicles designed to improve their fuel economy while maintaining the battery's state of charge. Since fuel cell systems have inherent limitations, such as a slow response time and low fuel efficiency, especially in the low power region, a battery system is typically used to assist them. To maximize the advantages of this hybrid type of configuration, a power distribution control strategy is required for the two power sources: the fuel cell system and the battery system. The required fuel cell power is procured using fuzzy rules based on the vehicle driving status and the battery status. In order to show the validity and effectiveness of the proposed power control strategy, simulations are performed using a mid-size vehicle for three types of standard drive cycle. First, the fuzzy logic-based power control strategy is shown to improves the fuel economy compared with the static power control strategy. Second, the robustness of the proposed power control strategy is verified against several variations in system parameters.