Shizuo Sasaki’s research while affiliated with Southwest Research Institute and other places

The present disclosure provides a method to operate an internal combustion engine comprising storing a fueling command map having fueling index values, each of the fueling index values defining values for a plurality of fueling parameters, and a plurality of predetermined non-linear relationships that directly relate fueling index values to in-cylinder oxygen mass values; determining a temporary fueling index value; determining an in-cylinder oxygen mass value; identifying a predetermined relationship that directly relates fueling index values to in-cylinder oxygen mass values from the plurality of predetermined relationships to provide an identified predetermined relationship; determining that a current relationship of the temporary fueling index value to the calculated oxygen mass value differs from the identified predetermined relationship; and adjusting the temporary fueling index value using at least one fueling correction model to provide a revised fueling index value that approaches the identified predetermined relationship.

The combination of premixed charge compression ignition (PCCI) and conventional Dl diesel combustion was studied on a light-duty diesel engine equipped with EGR and a common rail fuel injection system. This combustion mode is referred to as PCCI-DI combustion. The main objectives of the study were to examine the emissions, performance and combustion characteristics of the engine operating under various levels of PCCI-DI combustion to determine if this mode of combustion was a viable in-cylinder NO x emissions reduction strategy. The premixed charge was obtained with early pilot injections (up to three) using a custom engine controller. The engine test conditions were limited to light and medium loads and moderate engine speeds. Engine tests consisted of sweeps of pilot injection timing and quantity, and number of pilot injections. The results of this study suggest the greatest potential for reducing NOx emissions with PCCI-DI combustion exists at light loads (below 30%) and medium to low speeds. At 1500 rpm and 17% load, moderate NO x reductions of up to 15% were achieved, while a 9% NO x reduction was achieved at 2600 rpm and 54% load.