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Since the introduction of the EURO 5 emission legislation particulate matter emissions are no longer only a concern in the development of Diesel engine powertrains. In addition to particulate mass (PM) requirements the new European legislation will also foresee the implementation of a particulate number (PN) requirement for all spark ignition (SI) vehicles with the introduction of EURO 6. Measurements with state of the art gasoline engine powered vehicles show that conventional MPFI engines are already below the future proposed limits while gasoline engines with direct injection are above these limits and will require additional development efforts. This paper discusses both fuel system component requirements as well as control strategies in support of reducing particulate emissions. On the component side, mixture formation in regard to evaporation rate and penetration is a key factor.

In light of the growing emphasis on CO2 emissions reduction, Delphi has undertaken an internal development program to show the fuel economy benefits of lean, stratified combustion with its outwardly-opening solenoid injector in a vehicle environment. This paper presents the status of this ongoing development activity which is not yet completed. Progress to date includes a logical progression from single- and multi-cylinder dynamometer engines to the vehicle environment. The solenoid-actuated injector used in this development has an outwardly-opening valve group to generate a hollow-cone spray with a stable, well-defined recirculation zone to support spray-guided stratification in the combustion chamber. The engine management system of the development vehicle was modified from series-production configuration by changing the engine control unit to permit function development and calibration.

Due to its high number of free parameters, the new generation of gasoline engines with direct injection require an efficient calibration process to handle the system complexity and to avoid a dramatic increase in calibration costs. This paper presents a concept of specific toolboxes within a standardized and automated calibration environment, supporting the complexity of GDI engines and establishing standard procedures for distributed development. The basic idea is the combination of a new and more efficient online DoE approach with the automatic and adaptive identification of the region of interest in the high dimensional parameter space. This guarantees efficient experimental designs even for highly non-linear systems with often irregularly shaped valid regions. As the main advantage for the calibration engineer, the new approach requires almost no pre-investigations and no specific statistical knowledge.