Improved Vehicle-Specific Power Bins for Light-Duty Vehicles in Estimation of Carbon Dioxide Emissions in Beijing

Due to the alarming rate of climate change, fuel consumption and emission estimates are critical in determining the effects of materials and stringent emission control strategies. In this research, an analytical and predictive study has been conducted using the Government of Canada dataset, containing 4973 light-duty vehicles observed from 2017 to 2021, delivering a comparative view of different brands and vehicle models by their fuel consumption and carbon dioxide emissions. Based on the findings of the statistical data analysis, this study makes evidence-based recommendations to both vehicle users and producers to reduce their environmental impacts. Additionally, Convolutional Neural Networks (CNN) and various regression models have been built to estimate fuel consumption and carbon dioxide emissions for future vehicle designs. This study reveals that the Univariate Polynomial Regression model is the best model for predictions from one vehicle feature input, with up to 98.6% accuracy. Multiple Linear Regression and Multivariate Polynomial Regression are good models for predictions from multiple vehicle feature inputs, with approximately 75% accuracy. Convolutional Neural Network is also a promising method for prediction because of its stable and high accuracy of around 70%. The results contribute to the quantifying process of energy cost and air pollution caused by transportation, followed by proposing relevant recommendations for both vehicle users and producers. Future research should aim towards developing higher performance models and larger datasets for building APIs and applications.

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Introducing a New Emissions Certification Procedure for European Light-Duty Vehicles: Monte Carlo Simulation of the Potential Effect on Fleet Carbon Dioxide Emissions

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/2572-08 ◽

2016 ◽

Vol 2572 (1) ◽

pp. 66-77 ◽

Cited By ~ 6

Author(s):

Stefanos Tsiakmakis ◽

Biagio Ciuffo ◽

Georgios Fontaras ◽

Konstantinos Anagnostopoulos ◽

Vincenzo Arcidiacono ◽

...

Keyword(s):

Carbon Dioxide ◽

Monte Carlo Simulation ◽

Monte Carlo ◽

Carbon Dioxide Emissions ◽

Potential Effect ◽

Light Duty ◽

Certification Procedure ◽

Light Duty Vehicles

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Analysis of emissions from various driving cycles based on real driving measurements obtained in a high-altitude city

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/0954407019898959 ◽

2020 ◽

Vol 234 (6) ◽

pp. 1563-1571 ◽

Cited By ~ 1

Author(s):

Meng Lyu ◽

Xiaofeng Bao ◽

Yunjing Wang ◽

Ronald Matthews

Keyword(s):

High Altitude ◽

Real World ◽

Vehicle Emissions ◽

Control Strategies ◽

Driving Cycle ◽

Specific Power ◽

Test Cycle ◽

Light Duty ◽

And Control ◽

Light Duty Vehicles

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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Modeling real-world fuel consumption and carbon dioxide emissions with high resolution for light-duty passenger vehicles in a traffic populated city

Energy ◽

10.1016/j.energy.2016.07.067 ◽

2016 ◽

Vol 113 ◽

pp. 461-471 ◽

Cited By ~ 20

Author(s):

Shaojun Zhang ◽

Ye Wu ◽

Puikei Un ◽

Lixin Fu ◽

Jiming Hao

Keyword(s):

Carbon Dioxide ◽

High Resolution ◽

Fuel Consumption ◽

Real World ◽

Carbon Dioxide Emissions ◽

Passenger Vehicles ◽

Light Duty

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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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How Many Trajectories Are Needed to Develop Facility- and Speed-Specific Vehicle-Specific Power Distributions for Emission Estimation? Case Study in Beijing

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198119853550 ◽

2019 ◽

Vol 2673 (11) ◽

pp. 779-790

Author(s):

Zeyu Zhang ◽

Guohua Song ◽

Zhiqiang Zhai ◽

Chenxu Li ◽

Yizheng Wu

Keyword(s):

Sample Size ◽

Motor Vehicle ◽

Specific Power ◽

Activity Data ◽

Light Duty ◽

Emission Estimation ◽

Vehicle Activity ◽

Light Duty Vehicles ◽

Mean Square Errors

Vehicle-specific power (VSP) distributions, or operating mode (OpMode) distributions, are one of the most important parameters in VSP-based emission models, such as the motor vehicle emission simulator (MOVES) model. The collection of second-by-second vehicle activity data is required to develop facility- and speed-specific (FaSS) VSP distributions. This then raises the problem of how many trajectories are needed to develop FaSS VSP distributions for emission estimation. This study attempts to investigate the adaptive sample size for developing robust VSP distributions for emission estimations for light-duty vehicles. First, vehicle activity data are divided into trajectories and categorized into different trajectory pools. Then, the uncertainty of FaSS VSP distribution caused by sample size is analyzed. Further, the relationship between VSP distribution sample size and emission factor uncertainty is discussed. The case study indicates that error in developing FaSS VSP distributions decreases significantly with increased sample size. In different speed bins, the sample size required to develop robust FaSS VSP distributions and estimate emission factors is significantly different. In detail, in each speed bin, for a 90% confidence level, 30 trajectories (1,800 s) are enough to develop robust FaSS VSP distributions for light-duty vehicles with the root mean square errors (RMSEs) lower than 2%, which means errors in calculating fuel consumption and greenhouse gas (GHG) emissions are lower than 5%. However, 35 trajectories (2,100 s) are needed to estimate emissions of carbon monoxide (CO), nitrogen oxide (NOX), and hydrocarbons (HC) with an estimation error lower than 5%.

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Development of Operating Mode Distribution Models for Light-Duty Vehicles on Unrestricted Access Roadways

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198120937965 ◽

2020 ◽

Vol 2674 (10) ◽

pp. 416-428

Author(s):

Jia Li ◽

Hanhui He ◽

Bo Peng

Keyword(s):

Real World ◽

Operating Mode ◽

Specific Power ◽

Trajectory Data ◽

Average Speed ◽

The Real ◽

Light Duty ◽

Unrestricted Access ◽

Data Points ◽

Light Duty Vehicles

The key correlating traffic variable for modeling vehicle emissions has evolved from average speed to vehicle-specific power (VSP), and recently to operating mode as defined in Motor Vehicle Emission Simulator (MOVES). The analysis of operating mode and its distribution, however, requires a large amount of data and is time consuming and challenging. This paper attempts to build models between the operating mode distributions and the common traffic variable—average speed—to facilitate the emission estimation. Focusing on light-duty vehicles and unrestricted access roadways, a floating car survey was conducted separately on arterials and collectors in Shaoshan, China. The trajectory data were processed to reveal the characteristics of operating mode distributions. A key finding is that, when the data points of the operating mode of idle are excluded, the VSP distributions of the remaining data points follow logistic distributions and the parameters can be linearly regressed with the average speed. Arterials and collectors feature different operating mode distributions even at the same average speed, and therefore different models were developed. The models were then applied to generate operating mode distributions, which were validated with the real-world data from the test bed and which, when compared with the default values generated by MOVES, fit the real-world condition better.

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Characterization of Exhaust CO, HC and NOx Emissions from Light-Duty Vehicles under Real Driving Conditions

Atmosphere ◽

10.3390/atmos12091125 ◽

2021 ◽

Vol 12 (9) ◽

pp. 1125

Author(s):

Hui Mei ◽

Lulu Wang ◽

Menglei Wang ◽

Rencheng Zhu ◽

Yunjing Wang ◽

...

Keyword(s):

Specific Power ◽

Emission Measurement ◽

Nox Emissions ◽

Emission Rates ◽

Gaseous Emissions ◽

Passenger Cars ◽

Light Duty ◽

Driving Conditions ◽

Hc Emissions ◽

Light Duty Vehicles

On-road exhaust emissions from light-duty vehicles are greatly influenced by driving conditions. In this study, two light-duty passenger cars (LDPCs) and three light-duty diesel trucks (LDDTs) were tested to investigate the on-road emission factors (EFs) with a portable emission measurement system. Emission characteristics of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) emitted from vehicles at different speeds, accelerations and vehicle specific power (VSP) were analyzed. The results demonstrated that road conditions have significant impacts on regulated gaseous emissions. CO, NOx, and HC emissions from light-duty vehicles on urban roads increased by 1.1–1.5, 1.2–1.4, and 1.9–2.6 times compared with those on suburban and highway roads, respectively. There was a rough positive relationship between transient CO, NOx, and HC emission rates and vehicle speeds, while the EFs decreased significantly with the speed decrease when speed ≤ 20 km/h. The emissions rates of NOx and HC tended to increase and then decrease as the acceleration increased and the peak occurred at 0 m/s2 without considering idling conditions. For HC and CO, the emission rates were low and changed gently with VSP when VSP < 0, while emission rates increased gradually with the VSP increase when VSP > 0. For NOx NOx emission rates were lower and had no obvious change when VSP < 0. However, NOx emissions were positively correlated with VSP, when VSP > 0.

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