Development Of A Jing-Jin-Ji Area Light Duty Driving Test Cycle

Driving test cycle,which is conducted to detect the emission level,energy consumption,and development and evaluation of new model technology,is a foundational core technology of automobile development.At present,the Chinese regulation system employs the European “NEDC” cycle for vehicle test,but the traffic environment and travel law and driving manner of China are actually very different from that of Europe.Therefore,it is not scientific to apply the European cycle to match,test and evaluate Chinese vehicles.It is of great significance to establish the driving test cycle which can accurately reflect the actual running characteristics of the vehicle in our Country.This thesis takes the light vehicles of Jing-Jin-Ji area as the object of study.In order to develop a Jing-Jin-Ji area Light duty driving Test Cycle,it is necessary to carry out research the data acquisition,data analysis,developing driving test cycle and driving test cycle verification.The specific research content as follows:(1)Taking the four cities in Jing-Jin-Ji area,which are Beijing,Tianjin,Shijiazhuang and Langfang,as representative cities,and taking the method of autonomous driving as data collection method,this paper has conducted research on driving conditions of 280 light vehicles in Jing-Jin-Ji area,and about 65 million pieces of data has been collected,which are used as data samples for the development of driving test cycle.(2)The method of "short strip + road classification + GIS weighting factor + velocityacceleration distribution + cumulative frequency distribution + Chi-square test" is proposed for developing a Jing-Jin-Ji area Light duty driving Test Cycle(JLTC).Firstly,the sample data is repaired and smoothed.Secondly,the road attributes of each data are determined according to the latitude and longitude coordinates.Thirdly,the phases are cut and screened,and feature parameters of which are defined,and road type databases are devided.And finally,JLTC was developed according to the GIS weight factor and the method of chi square test.(3)The validity,rationality and representativeness of JLTC ware verified by two ways of data verification and simulation verification.In data validation,JLTC is compared with the original database,typical driving test cycle,Baidu GIS and Gao De traffic data characteristics,and the effectiveness and rationality of JLTC are validated.In simulation validation,the driving test cycle verification method combining simulation and laboratory testing is proposed for verificating JLTC.Using AVL Cruise software to build 6 simulation models of vehicle,and which are corrected by Vehicle Chassis Dynamometer.And the oil consumption level of the simulation models are calculated,which is compared with the data of Xiaoxiong fuel consumption and Publicity fuel consumption.It was found that there is little difference between them,and the effectiveness and practicabil of JLTC are validated.