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This paper analyzes the influence of actual driving conditions on gaseous pollutants and particulate emissions of heavy-duty diesel vehicles and evaluates the conversion efficiency of aftertreatment devices. A real driving emission (RDE) test involving urban, suburban, and highway conditions is carried out on a China VI heavy-duty diesel truck with aftertreatment devices, DOC, SCR, and DPF. The exhaust emissions are measured, and the results show that: the emission rates of CO, NO2, and PN increase with vehicle speed; NO2 accounts for 30%-50% of the total NOx emissions under most actual driving conditions; PN emissions are positively correlated with CO2 emissions. The average conversion efficiencies of the aftertreatment devices for NO2, NOx, PN, and CO are 84%, 93%, 99%, and 30%, respectively. SCR can reduce the GWP of NO effectively.

Accurate knowledge of diesel particulate filter (DPF) particulate matter (PM) loading is critical for robust and efficient operation of the combined engine-exhaust aftertreatment system. Furthermore, upcoming on-board diagnostics regulations require on-board technologies to evaluate the status of the DPF. This work describes the application of radio frequency (RF) - based sensing techniques to accurately measure DPF particulate matter levels. A 1.9L GM turbo diesel engine and a DPF with an RF-sensor were studied. Direct comparisons between the RF measurement and conventional pressure-based methods were made. Further analysis of the particulate matter loading rates was obtained with a mass-based total PM emission measurement instrument (TEOM) and DPF gravimetric measurements.