The Study On The China Heavy Duty Vehicle Driving Cycle And Investigation On Engine Cycle

Automotive driving cycle is basically used in evaluating the economic and emission characteristics of the vehicles and the engines.In comparison with the light duty vehicles,the emission of NOx and PM of the heavy duty vehicles becomes more remarkable.Recently,the Chinese emission regulations are implemented with the European transient cycle ETC and the European stable cycle ESC,which are hardly coincident with the Chinese heavy duty vehicles real driving circumstances.Therefore,building the suitable driving cycles and engine cycles for heavy duty vehicle plays an important role in fulfilling the mission of energy saving and environmental protection.This paper is based on the “China Automotive Test Cycle” project delivered by the Ministry of Industry and Information Technology of China,which have widely collected data of running vehicles in more than 40 typical cities during one year.Data with high quality is selected from 12 cities in 3 months,and sorted into mainly 2categories called bus and non-bus in terms of the applications of the vehicles in order to build the cycles.In the basis of large data processing,more than 1.2 million short segments have been divided.Furthermore,short segments are clustered;the clustered short segments have been filtered in terms of data quality,and eigenvalue like velocity,acceleration and so forth.Less than 50% of the short segments remain for the sake of developing cycles.The sorted short segments was freely combined by Cartesian product according to their time length.Chi-square test is deployed between the V-A distribution of the combined segments and the V-A distribution of the whole sample within the certain cluster,the smaller p value combinations are selected to be the output.Comparisons have been made between the in-use test cycles and the cycles built in this paper in both bus and non-bus categories.The results clearly demonstrate that cycles built in this paper are far more accurate to the reality.Subsequently,drive system model is made with the help of MATLAB program in order to convert the driving cycle into the engine cycle.Finally,efforts have been made to investigate the engine reference cycle.