Influence of the road slope on NOx emissions during start up

This paper has the purpose of estimating the NOx (Nitrous Oxides) emissions of vehicles equipped with ignition engines caused during the start-up of road slope. Studies currently carried out are scarce on driving right after start-up and its influence on NO_x emissions. For the selection of the test route, the methodology proposed in the Real Driving Emission Test (RDE) was used, for which, there is a Data Logger device that acquires the data from the On Board Diagnostic port (OBD) and geolocation with the help of its Global Positioning System (GPS). Using the Random Forest technique, it is estimated that the most important variable in NOx production is engine revolutions. When the startup is carried out on road slopes ranging from 2.5% to 6.4%, there is an increase of 60.45% in NO_x polluting emissions. In another situation, there is a decrease in the values of NO_x polluting emissions by 87%, when the start-up occurs during the descent of road slopes in the range from -4.9% to -0.9%.