In-Use Compliance Opportunity for Diesel Powertrains 2018-01-0877
In-use compliance under LEV III emission standards, GHG, and fuel economy targets beyond 2025 poses a great opportunity for all ICE-based propulsion systems, especially for light-duty diesel powertrain and aftertreatment enhancement. Though diesel powertrains feature excellent fuel-efficiency, robust and complete emissions controls covering any possible operational profiles and duty cycles has always been a challenge. Significant dependency on aftertreatment calibration and configuration has become a norm. With the onset of hybridization and downsizing, small steps of improvement in system stability have shown a promising avenue for enhancing fuel economy while continuously improving emissions robustness. In this paper, a study of current key technologies and associated emissions robustness will be discussed followed by engine and aftertreatment performance target derivations for LEV III compliant powertrains. The core of the discussion will be focused on identifying opportunities in engine and aftertreatment hardware and controls to position the diesel applications appropriately for future in-use compliance. Additionally, the authors will discuss the potential diesel powertrain hardware enhancements that could deliver improved emissions robustness while saving fuel, in real-world operation. Since OBD has become an integral part of in-use compliance, this paper will present novel ways to address the malfunction detection with reduced margin of variance while still delivering robust separation between worst performing acceptable (WPA) and best performing unacceptable (BPU) components. In conclusion, a summary of road maps to position diesel technology for future compliance targets will be presented.