Cleaner Diesel Using Model-Based Design and Advanced Aftertreatment in a Student Competition Vehicle 2008-01-0868

Traditionally in the United States, Diesel engines have negative connotations, primarily due to their association with heavy duty trucks, which are wrongly characterized as “dirty.” Diesel engines are more energy efficient and produce less carbon dioxide than gasoline engines, but their particulate and NO_x emissions are more difficult to reduce than spark ignition engines. To tackle this problem, a number of after-treatment technologies are available, such as Diesel Lean NO_x Traps (LNTs)), which reduces oxides of nitrogen, and the Diesel particulate filter (DPF), which reduces particulate matter. Sophisticated control techniques are at the heart of these technologies, thus making Diesel engines run cleaner. Another potentially unattractive aspect of Diesel engines is noise. The hybridization of a Diesel powertrain also offers significant opportunities for reducing noise emissions through the use of a starter-alternator for active engine vibration and noise reduction and by aggressively using engine start-stop and electric launch features.

Ohio State University used Model-Based Design in MATLAB and Simulink to address the challenge of integrating a Diesel engine in a crossover SUV as part of the Challenge X student competition. The team developed a number of advanced control strategies to meet vehicle technical specifications and validated these on the vehicle through real world tests. Challenge X is a four year competition, currently in its fourth year, that challenges 17 universities to re-engineer a Chevrolet Equinox for reduced energy consumption and emissions, while maintaining or improving stock performance.

The Ohio State University chose an architecture that utilizes a 1.9 L Diesel engine belted to a 10.6 kW starter/alternator and coupled to a six-speed automatic transmission. In addition, a larger 67 kW electric motor drives the rear axle in order to enable electric all wheel drive (eAWD) and electric launch capability. The Ohio State Team is currently fine tuning their vehicle to reduce emissions and improve drivability; this paper captures their experiences in this process.