Research on PEMS Test Data Processing Method and Cold Start Emission Evaluation Method of Heavy-Duty Diesel Vehicles

It is unreasonable to exclude all or part of the cold starting stage data in the current PEMS test data processing methods of heavy-duty diesel vehicles domestic and international. Therefore, this paper studies the PEMS data evaluation method including cold start stage data. In this study, PEMS tests were carried out on three different types of heavy-duty diesel vehicles. After that, the common data processing methods of the PEMS experiment were summarized and analyzed. In order to study the validity of different methods in processing the different stages’ experimental data of PEMS, the moving average window method (MAW) and cumulative averaging method (CA) were used to process the PEMS experiment data of cold stage and non-cold stage, respectively. Finally, a novel weighted evaluation method has been established creatively. The rationality of weight distribution was discussed, and 5 experiments were designed to verify the validity of the method. The results show that the MAW method only evaluates the effective window accounting for about 40%. The CA method can effectively evaluate the emission characteristics of cold and non-cold stages. The weighting method established based on the WHTC test can well reflect the contribution rate of pollutant emission in the cold start-up stage of the PEMS test of heavy diesel vehicles. Furthermore, for CO, NO x , and PN, the variation correlation coefficients between the emission in the cold stage and the weighted results are all above 0.8. The novel evaluation method can reasonably reflect the emission characteristics of the PEMS test of heavy-duty diesel vehicles during the cold stage and non-cold stage.