Research On Driving Cycles Of Urban Light Vehicles In Fuzhou City

As the basic data of vehicle energy consumption prediction and emission detection,driving cycle is the key technology of vehicle development and performance evaluation,and is also an important reference for the state to formulate relevant laws and regulations on vehicle energy conservation and emission reduction.However,the current standard test driving cycle of light vehicles in China are quite different from the actual driving conditions.In order to accurately evaluate vehicle performance and formulate reasonable national and local test standards,in this paper,the Fuzhou light vehicles is taken as the research object,and studies the construction method of urban light vehicle driving cycles.At the same time,the representative driving cycle of Fuzhou light vehicle are evaluated and analyzed by means of computer simulation and actual road test.The main research work of this paper includes:(1)Formulate a test acquisition scheme and collect the actual driving data of 70 light vehicles in Fuzhou City by self-driving method.The abnormal values in the original data are eliminated,the T4253 H filter is used to filter,and the data samples satisfying the construction requirements of driving conditions are obtained.(2)A driving cycle construction method based on combination optimization clustering and Markov chain method is proposed.The traditional principal component analysis method is improved by means of equalization treatment to improve the contribution rate of each principal component extraction;Silhouette function is introduced to determine the number of K-means clustering to avoid the impact of subjective determination on the results of traditional methods.Then,the driving cycles data of each sample is abstracted as a Markov process with time variation,and the Fuzhou light-duty vehicle driving cycles with 1200 seconds were synthesized by using state transition probability for state prediction.(3)Six characteristic parameters are obtained by factor analysis,which are highly related to vehicle energy consumption and emission.The driving cycles are screened and tested based on the CPV values of the parameters.In addition,the Fuzhou driving cycles is compared with the main driving cycles at home and abroad.The results show that the characteristics of each driving cycles are obviously different,and Fuzhou driving cycles has its own driving characteristics.(4)The Cruise simulation model is built to calculate the performance parameters under different driving cycles.The results show that the energy consumption under Fuzhou driving cycles is mainly consumed in acceleration mode,CO emissions mainly occur on urban roads driving cycles,while HC and NOX emissions mainly occur on expressways driving cycles.Compared with Fuzhou driving cycles,NEDC and WLTC underestimated fuel consumption by 26.89% and 6.24% respectively,and there were significant differences in the assessment of pollutant emissions.(5)The quantitative relationship between different parameters with vehicle energy consumption and emission is analyzed through actual road test.The results show that,compared with the standard test driving cycles,the representative driving cycles constructed by the proposed method have the lowest error rates for emission and fuel consumption prediction,which can better represent the actual driving situation of Fuzhou light vehicles.