China Adaptability Study Of On-Board Diagnostic Phase ?(OBD?) For Light-Duty Vehicles

With the rapid development of the automobile industry,the number of motor vehicles and drivers in China has grown rapidly.According to the statistics of the Traffic Management Bureau of the Ministry of Public Security,since 2010,the average annual increase of motor vehicles has reached more than 15 million,and the average annual increase of drivers is more than 20 million.By the end of 2017,the number of motor vehicles in the country had reached 310 million,including 217 million vehicles,and the rapid increase in vehicle ownership has brought tremendous pressure on China's energy and environment.Since 2000,China has implemented national I emission standards.After 15 years of development,the national IV emission standards have been implemented nationwide,and the national V emission standards have been implemented in key areas.In 2017,China has just begun to implement the National Five Standards.The Tier3 and LEVIII emission standards in the United States are stricter than the European emission standards.In particular,in terms of OBD standard requirements and management methods,the current automotive OBD emission standards in Europe and China are more complete and comprehensive.Controls for increased emissions from vehicle failures are superior to current European and Chinese standards.Therefore,it is extremely necessary to upgrade and upgrade China's automobile emission standards,especially OBD standards.This paper compares the On-board Diagnostics II(OBDII)with the European and Chinese OBD standards,and finds the advantages and disadvantages of different standards.Analysis of the differences in the impact of different standards on vehicle emissions.Based on the characteristics of OBD standards in the United States,Europe and China,the test specifications and evaluation methods for the six-stage medium-duty vehicle OBD project are proposed.The specific research contents are as follows:Firstly,the US OBDII,European EOBD(European On Board Diagnostics)vehicle emission standards were studied,and the specific regulations such as test items,test conditions,test methods and management methods of different standard systems were analyzed,and the current OBD standard for light vehicles in China was studied.The shortcomings and differences with the OBD automotive standards in the United States and Europe provide the basis for the development of regulations and the direction for revision of standards.Secondly,several different types of test vehicles(American Standard Vehicle,European Standard Vehicle,and National Five Vehicles)were used to test the requirements of the US OBDII and European EOBD vehicle emission standards.The differences between different standards were analyzed in detail,and the project was studied.Provide a data foundation.Thirdly,we studied the fuel system,evaporative leakage,permanent fault code,fire,catalyst,oxygen sensor,IUPR(In-Use Performance Ratio)and exhaust gas required for the addition of OBD emission standards in China's current light vehicle OBD emission standards.Feasibility of diagnostic test items such as EGR(Exhaust Gas Recirculation)and Diesel Particulate Filter(DPF).Finally,the feasibility of modifying the OBD project management method in the US OBDII in the OBD standard of China's light vehicles is studied.Based on the actual situation in China,comprehensive analysis and proposed a more comprehensive six-stage light vehicle OBD test specification,and verified the feasibility;The proposed test specification and evaluation method for the light vehicle OBD project has been applied in the text of the six-stage standard.