• Journal of Institute of Convergence Technology
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• v.4 no.1
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• pp.9-13
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• 2014

The purpose of this study is analysis to vehicle's fuel economy and emission gas characteristics by fuel type. The test vehicle were selected to similar weight and performance, the test vehicle was used three representative mode(CVS-75, HWFET and NEDC) in order to evaluation fuel economy and emission gas. For reference, environment pollution cost was calculated on the basis of the exhaust emissions occurred in the test in progress.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.109-112
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• 2006

In the recent studies, various types of multi mode electric variable transmission for hybrid electric vehicle have been proposed. Multi mode electric variable transmission consists of two or more different type planetary gear hybrid powertrain system(PGHP), which can change its power flow type by means of clutches for improving transmission efficiencies. Generally the power flows can be classified into three different types such as Input split, output split nd compound split. In This paper, we present velocity and torque equations of the input-split powertrain and analyze its optimal Performances. There are six combinations of the input-split powertrain, each combination has various lever length. We find optimal planetary gear ratios for fuel economy and acceleration performance, and compare performances of each combination.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.6
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• pp.87-93
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• 2007

It is complicate to analysis the systems, dual mode hybrid systems, because they are composed of many planetary gear sets. For the performance test, it needs to define the systems with representative parameters. In this paper, system parameters, $\alpha$, $\beta$, $\zeta$, are introduced to define the systems, and an arbitrary system like E-IVT developed by Renault Motors is converted to the general system having equivalent parameters, such as $\beta'$, $R'_b$. Pontryagin principle and Kuhn-Tucker condition method are applied to solve the constrained problems, by which the methodology for accelerating test is generalized, and the results of the simulation are reported. In addition, the effects of alternative strategies are mentioned. The method of fuel economy test at engine mode is also introduced. The results of test at engine mode is different from the results of optimal trajectory, but the fuel economy of the engine mode is related to the highway driving and optimized operating of the system.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.3
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• pp.42-49
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• 2014

The gasoline direct injection (GDI) system is considerably spreading in automotive market due to its advantages. Nevertheless, since GDI system emit higher particle matter (PM) due to its combustion characteristics, it is difficult to meet strengthened emission regulation in near future. For this reason, a combined GDI with MPI system, so-called, dual injection (DUI) system is being investigated as a supplemental measure for the GDI system. This paper focused on power and fuel consumption effect by injection mode strategy of DUI system in part load and idle engine operating condition. In this study, port fuel injectors are installed on 2.4 liters GDI production engine in order to realize DUI system. And, at each injection mode, DOE (design of experiment) method is used to optimize engine control parameters such as dual injection ratio, start of injection timing, end of injection timing, CAM position and so on. As a consequence, DUI mode shows slightly better or equivalent fuel efficiency compared to conventional GDI engine on 9 points fuel economy mode as well as MPI mode shows less fuel consumption than GDI mode during idle operation. Furthermore, DUI system shows improvement potential of maximum 2.0% fuel consumption and 1.1% performance compared to GDI system in WOT operating condition.

• Journal of ILASS-Korea
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• v.19 no.1
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• pp.33-39
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• 2014

Due to persist of high oil prices, LPG price stabilization and CNG modification project will be conducted. Present study describes the fuel efficiency and $CO_2$ emission characteristics on driving cycle mode and ignition advance condition change of CNG/LPG Bi-Fuel vehicle. In case of LPG Base and CNG Base condition, considerable $CO_2$ emissions are generated within range of high acceleration on FTP-75 and HWFET driving mode. However previous phenomena does not appear in CNG fuel $10^{\circ}CA$ and $15^{\circ}CA$ spark advance condition. As a result of analyzing the experimental data CNG $S/A10^{\circ}CA$, CNG $S/A15^{\circ}CA$, CNG Base, and LPG Base sequentially measured high fuel economy and low $CO_2$ emission characteristics.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.539-542
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• 2006

Many researches about next generation vehicles are trending toward HEV which has better fuel economy than an internal-combustion engine. But existing HEV has some defects at specific running states(eg. highway running It is possible that dual-mode hybrid system overcomes that defects. Mode change parameter, ${\gamma}$ helps to analyse the mode changing of dual mode hybrid and is applied at a numerical analysis on testing the performance. There is an additional constraint when vehicles drive on engine mode. No power assistance of battery applies on engine mode. Because vehicles must be sustained by only engine power while vehicle drives on constant speed mode. At the conclusion of this paper, graphs show the ability of motors that satisfy the equilibrium of the lever system. Designers can roughly determine capacities of the motors, parameters of the lever system by this analysing method.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.5
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• pp.97-106
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• 2009

An objective of this study is to give practical information that could be used for calculating pollutant emission factors and fuel economy from Korean Inspection & Maintenance program, which has been using steady state acceleration simulation mode. Concentration results from I/M test is adequately converted to mass emission factors and fuel efficiency data, which have unit of g/km and km/L, respectively. Exhaust volume flow(EVF), which is for converting emission result from concentration to mass, is measured by tracer method in various vehicle speed - power condition. It is found that there is an apparent second order relationship between EVF and vehicle inertia weight. EVF is expressed in function of vehicle inertia weight in order to estimate EVF in I/M site without measuring device. Converted mass emission results from measured EVF and raw emission analyzer show a satisfactory agreement with those from conventional CVS-bag type measurement system. Mass emission factors and fuel efficiency from measured EVF and estimated EVF also show good agreement to each other. Considering that an I/M program has great advantages to recruit-based emission test in terms of the number of test vehicle, the information in this study can be used for developing an alternative procedure to collect more various data to establish national database of mobile emission factors and fuel economy, even though the driving cycle in I/M program is steady state cycle rather than transient cycle.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.60-67
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• 2006

To improve the vehicle fuel economy, various technologies have been studied. Meanwhile it deteriorates fuel economy that the increased driving torque for Power Steering System (PSS) due to weighted vehicle and widened tire for low speed driving and parking. So the larger driving torque for PSS is, the lower fuel economy is. Therefore, the study about the effect of the driving torque for PSS and the engine total friction must be preceded to improve the vehicle fuel economy. In this study, a PSS module separated from the vehicle is used to measure the driving torque for PSS with respect to the pressure of PSS. The result shows that the driving torque for PSS was in direct proportion to the pressure of PSS 3 (N-m) driving torque for PSS vs. 10 (bar) pressure of PSS, and 8 (N-m) vs. 40 (bar). In addition, the driving torque and pressure for PSS was measured according to the engine speed in the component test condition which was in the vehicle condition. Measuring the driving torque for PSP in the vehicle condition was established by using the VeFAS which was a fuel economy analyzer developed in our lab and installing PSS By-pass line. The effect of the driving torque for PSS on the vehicle fuel economy was analyzed with FTP-75 cold start mode.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.2
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• pp.20-25
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• 2009

For many years there has been a trend to increased electrical energy consumption in cars caused by the replacement of mechanical parts by electronic or mechanical devices as well as the introduction of new electronic features. Whereas the number of electrical consumers continues to increase, the battery is still the only passive power source available. Because of this reason, needs for driving power of the engine accessories such as alternator system have increased. Usually, conventional alternator system is directly driven by the crankshaft of engine with belt. Since this increase bring about additional fuel economy. To improve this system automobile makers develops new controled alternator system. This paper focuses on fuel economy improvement according to control of alternator. In this paper, researches are performed on effect of type of Alternator system on fuel economy by experiment. And it is also calculated the effect on vehicle fuel economy using computer simulation with AVL cruise software. As a result, 0.64% of vehicle fuel economy improvement can be achieved in a vehicle with controled Alternator system compared to a vehicle with conventional Alternator system in NEDC mode.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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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.