Optimizing Fuel Consumption and Pollutant Emissions of a Spark Ignition Engine for Eco-Driving Applications

The transportation sector is a major contributor to both air pollution and greenhouse gas emissions. While optimizing fuel consumption reduces CO2 emissions, it can increase fuel-rich operation and cause higher HC and CO emissions. A simplified emissions model is thus introduced in order to account for the impact of air/fuel ratio on both the exhaust concentration of regulated pollutants and the catalyst efficiency. This model is used to solve the eco-driving problem with dynamic programming and a weighted objective function. An emission-centered and a consumption-centered scenario are compared on various driving cycles and with several time constraints. The optimal driving style in terms of emissions shows a substantial decrease in CO and HC while consumption stays relatively stable and NOx emissions slightly increase.