A Research On The Differences Between The RDE Test Results Analyzed By Moving Averaging Window Method And Power Binning Method

With the rapid development of China's economy and the continuous improvement of people's living standards,the number of motor vehicles in China is increasing day by day,and the environmental pollution caused by motor vehicle exhaust emissions is also attracting more and more attention.It has been proved by massive studies that the real-driving emission may differ greatly with the laboratory test emission.Under these circumstances,real driving emission(RDE)test has been added in the appendix of Euro 6 regulation and China 6 regulation to measure the emissions of vehicles under realistic road conditions.The RDE(Real Driving Emissions)procedure described in the annex of Euro 6 provides two methods to deal with real world emissions data,which are the Power Binning Method and the Moving Averaging Window Method.On the contrast,the China 6 only accepts Moving Averaging Window Method to process the data within the RDE procedure.In accordance with the RDE procedure regulated by China 6,the real world emissions were measured for 34 times with portable emission measurement system,using the Power Binning Method and the Moving Averaging Window Method to calculate and analyze the emission factors of all pollutants and the validity of the RDE test.Selecting 8 groups of RDE test data which can be determined as a valid test that using the Power Binning Method and the Moving Averaging Window Method and then contrastively analyze the emission factors calculated by the two methods.The results show that the emission factors under the Power Binning Method are larger than that under The Moving Averaging Window method.When removing the data of cold boot,vehicle idling and the stalling of engine in accordance with China-6,the emission factors reduce dramatically when adopting the Power Binning Method,which is fundamentally conformed with that under the Moving Averaging Window Method.It is the difference of data volume caused by removal of certain data that determines the difference of emission factors under two methods.The results of the validity of all the RDE test which are analyzed by the Power Binning Method and the Moving Averaging Window Method show that it is more likely to be a valid test when using the Moving Averaging Window Method to verify the validity of a RDE test compared with the Power Binning Method.Only when the rated power of the test vehicle is in the range of 100 kW ~ 160 kW and the urban traffic is smooth,a RDE test can be verified to be valid with certain probability using the Power Binning Method.It is reasonable that the China 6 only accepts the Moving Averaging Window Method to process the data of the RDE test in view of the fact that it has better applicability.