Research On Construction Of Driving Cycle And Emission Characteristics Of Light Vehicles In Taiyuan

In recent years,with the rapid development of automotive industry and the continued increase in vehicle ownership,urban traffic congestion,energy crisis and serious air pollution have become hot issues.Vehicle driving cycles are important for evaluating vehicle pollution emission and fuel consumption.Developed countries as the United States,Europe,and Japan have developed driving cycles that meet their actual road and traffic.China has been using the European driving cycle.However,China has a vast territory,there are certain differences in road planning,traffic conditions and environment in each city.And the difference is even great when compared with European countries.Therefore,European driving cycles can not reflect Chinese actual traffic condition.China urgently needs to set up a national unified driving cycle,which is of great significance for developing vehicle technology and reducing emissions.This paper takes 70 light vehicles as the research object and reasonably develops a program of test date acquisition for one year.The datas cover different road types,vehicle types,vehicle drivers,driving hours,and seasons of driving conditions.It is in order to provide a reasonable and comprehensive date sources for constructing driving cycle of light vehicles in Taiyuan.Combining short-stroke method and classification method to construct driving cycle,and using principal component analysis and cluster analysis to process data.Dividing all the short trips into three categories and calculating the correlation coefficient of each short trip.Then combining with the estimated time of driving cycles,the expressway driving cycle,trunk road driving cycle,secondary trunk driving cycle and the comprehensive driving cycle for Taiyuan are constructed.Comparing the characteristic parameters with overall date and analysising the speed-acceleration joint distribution,it is concluded that the construction cycles are quite different from other country's typical cycles.The ADVISOR software is used to establish the simulation model of a light vehicle,and the actual driving cycles of the vehicle were simulated in order toverify the model's credibility.The comprehensive driving cycle and other typical cycles are simulated under this model.Then comparing the simulation results of fuel consumption and emissions performance,it is concluded that the discharge of pollutants when driving under Taiyuan driving cycle much higher.The AVL-MOVE portable emission tester and flow meter is used to build vehicle exhaust test platform.The test data shows that the driving mode,speed and acceleration of the vehicle have a great impact on the emissions of exhaust gas.The exhaust emissions in the accelerated mode are much higher than other modes,and the greater the acceleration,the greater the emission value.The emission values of CO₂,CO,CH,and NO_X are much high when driving under30 kilometers per hour.In the range of 30 kilometers per hour to 60 kilometers per hour,the emission performance are all better.When the speed over 60kilometers per hour,the emission values of CO and CH will increase with the speed.