A Study Examining the Effects of Driver Profile and Route Characteristics on Vehicle Performance and Tailpipe Emissions under Virtual Real Driving Scenarios

The design of modern aftertreatment systems to meet Real Driving Emissions (RDE) regulations is a significant challenge faced by manufacturers today. This is because testing vehicles under RDE conditions is both time consuming and expensive. In this study, we quantify the effect of real driving conditions on vehicle performance (efficiency and emissions) using a system model comprised of vehicle and aftertreatment subsystems, built using the commercial simulation software GT-SUITE. The developed system model will allow manufacturers to predict vehicle performance and prospective emissions under real driving conditions early in the development cycle and to ensure compliance with current and future regulations. The engine used in this study is a 2.0 L turbocharged diesel engine, while the aftertreatment system consists of a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), and a selective catalytic reduction (SCR).

The simulated real driving route was generated by using a new feature that uses real-time global positioning system (GPS) data to calculate a driving route from a defined starting point to a destination. The feature considers current traffic conditions (traffic lights, traffic density, speed limits, etc.) and allows different driver profiles to be simulated. In this study, a city driving route in Los Angeles (LA) County and a highway driving route from New York City (NYC) to LA were simulated with average traffic light durations of 15 s and 90 s. In addition, two driver profiles were simulated for each route and traffic light duration. The effect of all these factors on the observed engine efficiency and emissions is quantified and discussed.

The aftertreatment system features a high-fidelity DOC model that was developed based on synthetic gas bench (SGB) data from the literature with additional mechanisms for sulfur poisoning and platinum oxidation. The effects of sulfur poisoning, as well as platinum oxidation on DOC-out emissions, were also investigated under the real driving scenarios.