• Journal of ILASS-Korea
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• v.22 no.3
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• pp.122-128
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• 2017

Currently, the proportion of diesel vehicles in all automobile has grown significantly over the past few years. Air pollutant also grew up and became a social problem. In particular, the issue of NOx emissions caused by NOx high emission in real driving has become a global issue. Despite the fact that the regulatory and reduction project of the new vehicle is actively carried out, there are no existence regulations of In-use diesel vehicle's NOx emission. Therefore, the emission characteristics of the in-use diesel vehicles were investigated to seek ways to reduce NOx emissions in this study. The test targets were used in 237 close inspection of exhaust gases and model year varied from 1996 to 2011. However, the classification of emissions by emission standards differed considerably from NOx emissions. This means that the selection method for early retirement targets should be converted from model year to amount of emissions. If the current early retirement program was applied to the existing system, pre-Euro 3 was 22.530 g/km and Euro 4 was 21.810 g/km to NOx reduction. However, when the vehicle was changed to high emission target vehicle, NOx reduction increase maximum 84.705 kg/yr. According to the study results, an effective reduction in NOx emissions can be achieved if an earlier target in expanded to Euro 4 vehicles.

• Journal of ILASS-Korea
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• v.23 no.3
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• pp.122-127
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• 2018

Recently, registrated passenger cars have increased and were close about seventy million at the end 2017 year in Korea. Among the passenger car using gasoline fuel make up forty six percentage of total registrated vehicles. In this study, investigation on real driving emission characteristics in the passenger car using gasoline fuel with various engine displacements were carried out. The real driving emission characteristics were measured and analyzed by using PEMS (Portable Emission Measurement System). PEMS was composed of gas analyzer, emission flow meter and sample conditioning system et al. Also, test six vehicles were selected to the gasoline passenger car with engine displacement from 1.6L to 3.7L. Two test routes with engine start of cold and hot conditions were applied to analyze the emission characteristics of RDE, respectively. The results show that the $CO_2$ emission have a increasing trend as the engine displacement and vehicle weight. Also, it is guessed that the $CO_2$ emission and vehicle weight were more correlated than the engine displacements. On the other hand, NOx emissions of RDE have not increasing or decreasing tendency according engine displacements or vehicle weight because the activation of three-way catalyst in the gasoline vehicles.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.287-296
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• 2017

Although emission regulations have been gradually strengthened in the past decade, the road transport section remains the most important source of NOx emission in air pollution. One reason is that there has been an increase in the proportion of diesel vehicles and in the volume of traffic. In addition, the certification procedure for standard emission limit does not sufficiently reflect real traffic condition and various driving patterns. Therefore, the European Commission(EC) has recently come up with the RDE-LDV(Real driving emissions-light duty vehicle) regulations, and the Ministry of Environment in Korea has been conducting research on evaluating RDE-LDV with PEMS(Portable Emission Measurement Systems). According to the trip requirements of the 2nd RDE package announced by the EC, the objectives of the present study include the development of Korean RDE routes to reflect domestic traffic and road conditions. Based on the results, both RDE routes are in correct compliance with RDE-LDV regulations, including trip requirements and trip dynamics. KOR-NIER Route 1, in particular, has a higher driving load in rural driving with regard to excessive gradient of elevation compared to KOR-NIER Route 2, including relatively plane rural driving.

• Journal of Climate Change Research
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• v.4 no.4
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• pp.359-369
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• 2013

In this paper, correlations between driving parameters and $CO_2$ of light-duty vehicles have been analyzed. Three test vehicles equipped with PEMS (Portable Emission Measurement System) have been driven in real-road in urban areas of Seoul. Averaged vehicle speed, RPA(Relative Positive Acceleration) and stop ratio have been selected as main driving parameters. The analysis have been conducted in interrupted and uninterrupted road types. Averaged values in various driving conditions have been calculated with distance based moving averaging window method. The multiple linear regression method have been applied to account for correlation between driving parameters and $CO_2$ emissions. This approach has shown statistically that $CO_2$ emission per distance (g/km) have tendencies to be increased as decreased averaged vehicle speed and increased RPA and stop ratio. Compared with uninterrupted traffic, interrupted traffic have shown the lower vehicle speed and the higher RPA and stop ratio. These characteristics of driving parameters in interrupted traffic should cause the higher $CO_2$ emission per distance.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.2
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• pp.191-206
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• 2018

In this study, the HAPs(Harzard Air Pollutants) emission factor level of Starex and Grand Carnival was tested using PEMS (Portable Emissions Measurement System) on real road driving. As a result of RDE (Real Driving Emission test), the overall vehicle speed pattern showed similar characteristics. The real-road driving test at constant speed revealed emission factor is inversely proportional relationship to constant speed. Results of accelerating with speed limit on the real-road were shown as followings; Uran (less than 45 km/h)>Rural (<45 km/h, less than 80 km/h)>Motorway (>80 km/h). Moreover, the sudden acceleration and deceleration in driving at high speed was the increasing factor to the HAPs emission factor. This tendency is considered to be influenced by the operating environment on real roads.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.3
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• pp.139-146
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• 2019

As the number of electric vehicles (EVs) in Jejudo Island increases, the secondary use of EV batteries is becoming increasingly mandatory not only in reducing greenhouse gas emissions but also in promoting resource conservation. For the secondary use of EV batteries, their capacity and performance at the end of automotive service should be evaluated properly. In this study, the battery state information from the on-board diagnostics or OBD2 port was acquired in real time while driving three distinct routes in Jejudo Island, and then the battery operating characteristics were assessed with the driving routes. The route with higher altitude led to higher current output, i.e., higher C-rate, which would reportedly deteriorate state of health (SOH) faster. In addition, the SOH obtained from the battery management system (BMS) of a 2017 Kia Soul EV with a mileage of 55,000 km was 100.2%, which was unexpectedly high. This finding was confirmed by the SOH estimation based on the ratio of the current integral to the change in state of charge. The SOH larger than 100% can be attributed to the rated capacity that was lower than the nominal capacity in EV application. Therefore, considering the driving environment and understanding the SOH estimation process will be beneficial and necessary in evaluating the capacity and performance of retired batteries for post-vehicle applications.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.4
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• pp.443-453
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• 2011

Real-time Traffic Information Service could play a key role in reducing incomplete combustion time remarkably since it can provide traffic information in real-time basis. Emission characteristics of test engines were studied in terms of travel distance and speed. The present study focused on a north district in Daegu, 12 km. The driving for the emission test was done at 8AM, 3PM, 7PM which represents various traffic conditions. The reduced emissions of Greenhouse Gases (GHG) have been measured for a travel distance running at different loads (conventional shortest route and Real-time Traffic Information) and GHG ($CO_2$, $CH_4$, $N_2O$) are all inventoried and calculated in terms of existing emission factors. The emission of GHG has been shown to reduce linearly with travel distance: $CO_2$ (9.15%), $CH_4$ (18.43%), $N_2O$(18.62%).

• Journal of Climate Change Research
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• v.6 no.2
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• pp.143-158
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• 2015

This study developed the emission intensity estimation method of GHGs by considering the characteristics of the models and time series. The telematics device was installed on the vehicle (OBD-II) to collect information on the operation conditions from each sample vehicle of public authorities. As a result of comparing the mileage distance and fuel consumption, the matching degree is analyzed very high, showed a ${\pm}1{\sim}4%$ error for each vehicle. By comparing driving record diary of vehicles managed by public authorities, this study presents the method that can be used to verify driving information in order to derive the GHGs emission intensity.

• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.117-126
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• 2012

The transportation sector accounts for 33% of the total $CO_2$ emissions. Effective control measures for reducing $CO_2$ emissions are urgently needed to address global warming. Objective and reliable methods to estimate $CO_2$ emissions are a prerequisite for the implementation of such effective control measures. However, existing models have not been successful. Even though the average-speed model is one of the most convenient and useful methods for estimating $CO_2$ emissions, it cannot distinguish between a variety of roads as well as traffic conditions in the model. The results of this study found that there may be significant discrepancies between emissions estimated by the current average-speed model and those measured in real driving conditions. This paper proposed the subdivision of emission factors in the average-speed model depending on both traffic and road conditions.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.7-18
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• 2007

There are few studies on air pollution due to vehicle emissions in spite of the importance of this field. Therefore, this study describes trends and suggests implications through analysis relating to existing emissions research. This study has been divided into three areas. The first part is about estimating vehicle emissions. In this part, the authors analyze limits in ways of calculating emissions in the existing macroscopic view and then suggest the development of a model for calculating emissions considering velocity and acceleration. These variables are a function of traffic and individual driving behavior in the microscopic view. The second part is about management techniques for reducing vehicle emissions. The traffic management techniques for reducing vehicle emissions should conform to regional characteristics. The final part is about traffic operation for reducing vehicle emissions. The authors suggest the development of a micro-simulator and then the development of strategies for traffic operation. It is necessary to design better models estimating emissions and then, using real time data, to make a monitoring system simulating emission rates. This study serves as a literature review to make a foundation for further research about emissions research for transportation engineering.