Binomial multifractal features of worldwide harmonized light duty vehicles test cycle

Vehicle emissions standards and regulations remain weak in high-altitude regions. In this study, vehicle emissions from both the New European Driving Cycle and the Worldwide harmonized Light-duty driving Test Cycle were analyzed by employing on-road test data collected from typical roads in a high-altitude city. On-road measurements were conducted on five light-duty vehicles using a portable emissions measurement system. The certification cycle parameters were synthesized from real-world driving data using the vehicle specific power methodology. The analysis revealed that under real-world driving conditions, all emissions were generally higher than the estimated values for both the New European Driving Cycle and Worldwide harmonized Light-duty driving Test Cycle. Concerning emissions standards, more CO, NOx, and hydrocarbons were emitted by China 3 vehicles than by China 4 vehicles, whereas the CO2 emissions exhibited interesting trends with vehicle displacement and emissions standards. These results have potential implications for policymakers in regard to vehicle emissions management and control strategies aimed at emissions reduction, fleet inspection, and maintenance programs.

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Development of the Worldwide Harmonized Test Procedure for Light-Duty Vehicles

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/2503-12 ◽

2015 ◽

Vol 2503 (1) ◽

pp. 110-118 ◽

Cited By ~ 21

Author(s):

Biagio Ciuffo ◽

Alessandro Maratta ◽

Monica Tutuianu ◽

Konstantinos Anagnostopoulos ◽

Georgios Fontaras ◽

...

Keyword(s):

Carbon Dioxide Emissions ◽

Test Procedure ◽

Test Results ◽

Test Cycle ◽

Test Procedures ◽

United Nations Economic Commission ◽

Vehicle Performance ◽

Light Duty ◽

Economic Commission ◽

Light Duty Vehicles

To assess vehicle performance on criteria compounds, carbon dioxide emissions, and fuel energy consumption, laboratory tests are generally carried out. During these tests, a vehicle is driven on a chassis dynamometer (which simulates the resistances the vehicle encounters during its motion) to follow a predefined test cycle. In addition, all conditions for running a test must strictly adhere to a predefined test procedure. The procedure is necessary to ensure that all tests are carried out in a comparable way, following the requirements set by the relevant legislation. Test results are used to assess vehicle compliance with emissions limits or to evaluate the fuel consumption that will be communicated to customers. Every region in the world follows its own approach in carrying out these types of tests. The variations in approaches have resulted in a series of drawbacks for vehicle manufacturers and regulating authorities, leading to a plethora of different conditions and results. As a step toward the harmonization of the test procedures, the United Nations Economic Commission for Europe launched a project in 2009 for the development of a worldwide harmonized light-duty test procedure (WLTP), including a new test cycle. The objective of the study reported here was to provide a brief description of WLTP and outline the plausible pathway for its introduction in European legislation.

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Comparison of Portable Emissions Measurement Systems (PEMS) with Laboratory Grade Equipment

Applied Sciences ◽

10.3390/app8091633 ◽

2018 ◽

Vol 8 (9) ◽

pp. 1633 ◽

Cited By ~ 22

Author(s):

Roberto Varella ◽

Barouch Giechaskiel ◽

Luís Sousa ◽

Gonçalo Duarte

Keyword(s):

The European Union ◽

Chassis Dynamometer ◽

Test Cycle ◽

Measurement Systems ◽

Type Approval ◽

Light Duty ◽

Uncertainty Estimates ◽

European Union Legislation ◽

Urban Conditions ◽

Light Duty Vehicles

Real-driving emissions (RDE) testing with portable emissions measurement systems (PEMS) during the type approval and in-service conformity of light-duty vehicles was recently introduced in the European Union legislation. In this paper, three PEMS were compared with laboratory analyzers connected to the tailpipe and the dilution tunnel. The tests were conducted with two Euro 6 vehicles (one gasoline and one diesel) performing the World harmonized Light vehicles Test Cycle (WLTC) and a pre-recorded RDE cycle on a chassis dynamometer. The results showed that the differences of the PEMS gas analyzers compared to the laboratory references were typically within 2% for CO2 and 5% for NOx. The CO2 and NOx mass emissions were within 10% and 15%, respectively, with only a few exceptions. The exhaust flow rate measurements were within 10% at low speeds (urban conditions), and 5% at higher speeds. These results confirm the legislated permitted tolerances and the 2017 PEMS uncertainty estimates.

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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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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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