Fuel Consumption And Emission Speed Correction Factors Errors Control Based On VSP Distributions

In the context of "Carbon Peaking" and "Carbon Neutrality",more accurate estimation of traffic fuel consumption and emission are needed.The high-resolution fuel consumption and emission factor based on Vehicle Specific Power(VSP)Distribution is an important parameter for the calculation of vehicle fuel consumption and emissions,which can be obtained by two parameters: VSP distribution and emission rate.These two parameters are developed based on the local vehicle operating condition and emission data.The amount and quality of collected data are the key factors that cause the error and fluctuations of fuel consumption and emission speed correction factor curve.In this context,by analyzing the sensitivity of fuel consumption and emission factors to power distribution and emission rate respectively,a data amount calculation model based on error control was established.The goal is to improve the quality of collected vehicle operating condition data and emission data and control the errors of fuel consumption and emission factor.This research will provide support for the conduction of traffic emission research and the formulation of relevant policies.The main results and conclusions of this study are as follows:(1)Influence mechanism between VSP distribution,emission rate and Fuel Consumption and Emission Speed Correction Factor.By designing the error scenarios of VSP Distribution and emission rate,it is found that the error of VSP Distribution at individual average speed is the reason for the abnormal fluctuation of fuel consumption and emission speed correction factor curve.The emission rate error is the reason for the overall error of the fuel consumption and emission speed correction factor curve.(2)Sensitivity analysis between Fuel Consumption and Emission Speed Correction Factor and VSP Distribution and emission rate.The variation rules of parameters were designed,and sensitivity coefficient indexes were established to quantify the influence of VSP Distribution and emission rate in each VSP bin on fuel consumption and emission speed correction factors at a specific average speed.The results show that the sensitivity between fuel consumption and emission speed correction factors and VSP Distribution and emission rate are different at different VSP bins.When the vehicle average speed is between 20km/h and 120km/h,the most sensitive VSP bin changes from0 k W/t at 20km/h to 5 k W/t at 120km/h when the fuel consumption and emission speed correction factor changes in the opposite direction of the VSP Distribution.When fuel consumption and emission speed correction factor changes in the same direction of the VSP Distribution,the most sensitive VSP bin changes from 4 k W/t to 18 k W/t.The sensitivity coefficient between fuel consumption and emission speed correction factor and emission rate is always positive.With the increase of average speed,the most sensitive VSP bin changes from 3k W/t to 16 k W/t.The errors of the fuel consumption and emission speed correction factor are positively correlated to the errors of VSP Distribution and the emission rate: at different average speeds,increase or decrease of 1%of the VSP Distribution or emission rate can cause about 0.02%-0.05% or 0.07%-0.14%change in the value of fuel consumption and emission speed correction factor.(3)Model of estimating required data amount of vehicle operating condition and emission data based on Fuel Consumption and Emission Speed Correction Factor error control.On the basis of controlling the error of fuel consumption and emission speed correction factor,the allowable error and data amount of all VSP bins are obtained by numerical simulation.The results show that at 95% confidence level,the average speed is within [20,120]km/h,and if the error of fuel consumption and emission speed correction factor is less than 1% : the emission rate data should be collected for at least 40 minutes.The data amount of each VSP bin(the resolution of VSP bin is 1k W/t)has a significant difference.The data amount of VSP bin at [-3,9] k W/t accounts for83.6% of the total amount of emission rate data.At least 710 minutes of operating condition data were collected at each average speed,and with the same error,the data amount of vehicle operating condition within the range of [80,120] km/h was lower.In order to eliminate the abnormal fluctuation of curve,it is necessary to greatly increase the data amount of operating condition within the range of [64,80]km/h.(4)Case study.Based on the model of estimating required data amount,the application of ecological driving behavior identification and the PEMS experimental data quality control are designed respectively.It is founded that: the relative error of ecological driving behavior evaluation results decreases by 57.68% when the data collected meets the minimum demand.When the data collected by PEMS meets the minimum demand,the error of fuel consumption and emission speed correction factor converges to desired range(1%)under all average speed bins.