Estimating the effectiveness of vehicle emission regulations for reducing NOx from light-duty vehicles in Korea using on-road measurements

The CO2 moving average window(MAW) method is used to process RDE (real drive emissions) emissions data in China 6 light duty vehicle emissions regulations, while the Euro 6 light duty vehicle emission regulations allow to use both of MAW and power binning(PB) method to deal with RDE emission data. In order to study the difference between the two data processing methods and analyze the differences in the emission results, 10 different types of light duty vehicles are conducted RDE test with PEMS (portable emissions measurement system), and the test data are processed by the two methods separately. The results show that there is a little difference between MAW and PB, while both of them can satisfy the vehicle emission assessment. The PB method calculates the emission factors higher than the MAW method. After removing the cold start and idle condition data, the results of PB is similar to MAW. Besides, reducing the average speed limit of urban working conditions in PB has a greater impact on the urban driving condition emission factor, but less on the whole cycle emission factor.

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Aftertreatment DeNOx Systems for Future Light Duty Lean-Burned Emission Regulations

Catalysts ◽

10.3390/catal11020188 ◽

2021 ◽

Vol 11 (2) ◽

pp. 188

Author(s):

Beñat Pereda-Ayo ◽

Juan Ramon González-Velasco

Keyword(s):

United States ◽

The United States ◽

Light Duty ◽

Emission Regulations ◽

Light Duty Vehicles

Future light duty vehicles in Europe and the United States are required to be certified, owing to progressively more and more stringent regulations [...]

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Road vehicles - Supplementary grip devices for tyres of passenger cars and light duty vehicles

10.3403/bsen16662 ◽

2020 ◽

Keyword(s):

Road Vehicles ◽

Passenger Cars ◽

Light Duty ◽

Light Duty Vehicles

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Analysis of Driving Dynamics Considering Driving Resistances in On-Road Driving

Energies ◽

10.3390/en14123408 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3408

Author(s):

Jingeun Song ◽

Junepyo Cha

Keyword(s):

Combustion Engine ◽

Vehicle Speed ◽

Driving Dynamic ◽

Engine Emissions ◽

Engine Load ◽

Positive Acceleration ◽

Emission Regulations ◽

Transportation Emissions ◽

Light Duty Vehicles ◽

Dynamic Variables

Internal combustion engine emissions are a serious worldwide problem. To combat this, emission regulations have become stricter with the goal of reducing the proportion of transportation emissions in global air pollution. In addition, the European Commission passed the real driving emissions–light-duty vehicles (RDE-LDV) regulation that evaluates vehicle emissions by driving on real roads. The RDE test is significantly dependent on driving conditions such as traffic or drivers. Thus, the RDE regulation has the means to evaluate driving dynamics such as the vehicle speed per acceleration (v·apos) and the relative positive acceleration (RPA) to determine whether the driving during these tests is normal or abnormal. However, this is not an appropriate way to assess the driving dynamics because the v⋅apos and the RPA do not represent engine load, which is directly related to exhaust emissions. Therefore, in the present study, new driving dynamic variables are proposed. These variables use engine acceleration calculated from wheel force instead of the acceleration calculated from the vehicle speed, so they are proportional to the engine load. In addition, a variable of driving dynamics during braking is calculated using the negative wheel force. This variable can be used to improve the accuracy of the emission assessment by analyzing the braking pattern.

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Monte Carlo Simulation Methodology to Assess the Impact of Ambient Wind on Emissions from a Light-Commercial Vehicle Running on the Worldwide-Harmonized Light-Duty Vehicles Test Cycle (WLTC)

Energies ◽

10.3390/en14030661 ◽

2021 ◽

Vol 14 (3) ◽

pp. 661

Author(s):

Alexandros T. Zachiotis ◽

Evangelos G. Giakoumis

Keyword(s):

Monte Carlo Simulation ◽

Energy Consumption ◽

Commercial Vehicle ◽

Ambient Wind ◽

Simulation Methodology ◽

Road Load ◽

Light Duty ◽

Light Commercial Vehicle ◽

Light Duty Vehicles ◽

The Impact

A Monte Carlo simulation methodology is suggested in order to assess the impact of ambient wind on a vehicle’s performance and emissions. A large number of random wind profiles is generated by implementing the Weibull and uniform statistical distributions for wind speed and direction, respectively. Wind speed data are drawn from eight cities across Europe. The vehicle considered is a diesel-powered, turbocharged, light-commercial vehicle and the baseline trip is the worldwide harmonized light-duty vehicles WLTC cycle. A detailed engine-mapping approach is used as the basis for the results, complemented with experimentally derived correction coefficients to account for engine transients. The properties of interest are (engine-out) NO and soot emissions, as well as fuel and energy consumption and CO2 emissions. Results from this study show that there is an aggregate increase in all properties, vis-à-vis the reference case (i.e., zero wind), if ambient wind is to be accounted for in road load calculation. Mean wind speeds for the different sites examined range from 14.6 km/h to 24.2 km/h. The average increase in the properties studied, across all sites, ranges from 0.22% up to 2.52% depending on the trip and the property (CO2, soot, NO, energy consumption) examined. Based on individual trip assessment, it was found that especially at high vehicle speeds where wind drag becomes the major road load force, CO2 emissions may increase by 28%, NO emissions by 22%, and soot emissions by 13% in the presence of strong headwinds. Moreover, it is demonstrated that the adverse effect of headwinds far exceeds the positive effect of tailwinds, thus explaining the overall increase in fuel/energy consumption as well as emissions, while also highlighting the shortcomings of the current certification procedure, which neglects ambient wind effects.

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Chemical characterization of PM2.5 emitted from China IV and China V light-duty vehicles in China

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.147101 ◽

2021 ◽

Vol 783 ◽

pp. 147101

Author(s):

Yanzhao Hao ◽

Shunxi Deng ◽

Zhaowen Qiu ◽

Zhenzhen Lu ◽

Hui Song ◽

...

Keyword(s):

Chemical Characterization ◽

Light Duty ◽

Light Duty Vehicles

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Revised Method for Calculating Departure Sight Distance at Two-Way Stop-Controlled (TWSC) Intersections

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/03611981211031544 ◽

2021 ◽

pp. 036119812110315

Author(s):

Essam Dabbour ◽

Said M. Easa

Keyword(s):

Traffic Safety ◽

Major Road ◽

Light Duty ◽

Sight Distance ◽

Data Loggers ◽

Global Positioning ◽

Actual Field ◽

System Data ◽

Negative Impacts ◽

Light Duty Vehicles

This paper introduces realistic acceleration profiles for light-duty vehicles departing from rest at two-way stop-controlled (TWSC) intersections where minor roads (controlled by stop signs) intersect with uncontrolled major roads. The new profiles are based on current vehicle characteristics and driver behavior patterns. They are established based on actual field data collected using global positioning system data loggers that recorded the positional and speed data of various experimental vehicles starting from rest at TWSC intersections. Acceleration profiles are established in this paper and are used to develop a revised method for calculating the departure sight distance at TWSC intersections. Design tables were created to provide realistic sight distance values at TWSC intersections for different design speeds and number of lanes on the major road. It was found that the current values of intersection sight distance suggested by the design guides may be inadequate. Such values may force some approaching drivers on the major road to reduce their speeds or move to different traffic lanes to avoid conflicting with the departing vehicles. These maneuvers may have negative impacts on traffic safety. Therefore, implementing the revised method for calculating intersection sight distance, as presented in this paper, may ultimately reduce traffic collisions at TWSC intersections.

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