Cylinder Pressure-Based Combustion Controls for Advanced Diesel Combustion With Multiple-Pulse Fuel Injection

For current diesel engines, multiple fuel injection mechanisms enabled by high rail-pressure systems is a key lever that can help to achieve further reduction in engine-out emissions and improvements in performance. In the case of multiple fuel injections, timing and fuel pulse-width for each pulse (or, equivalently, fuel amount) need to be optimized and maintained for low emissions, fuel economy, noise, and exhaust thermal management over different operating ranges. This paper presents a research study on the application of pressure-based controls for management of the multiple-pulse fuel injection, particularly main and post injections, to maintain a robust combustion behavior against disturbances and variations in the field. Several control features for simultaneous management of main and post injections are proposed and experimentally validated on a 6.6 L V8 diesel engine in an engine dynamometer, both at steady-state and during federal test procedure transients.