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Gasoline engine downsizing is already established as a technology for reducing vehicle CO2 emissions. Further benefits are possible through more aggressive downsizing, however, the tradeoff between the CO2 reduction achieved and vehicle drivability limits the level of engine downsizing currently adopted by vehicle manufacturers. This paper will present the latest results achieved from a very heavily downsized engine, and resulting demonstrator vehicle, featuring eSupercharging in combination with a conventional turbocharger. The original 1.2 litre, 3-cylinder, MAHLE downsizing engine has been re-configured to enable a specific power output in excess of 160 kW/litre. Of key importance is a cost effective, efficient and flexible boosting system.

MAHLE Powertrain have developed a plug-in hybrid demonstrator vehicle. To support this one-off prototype, a flexible control unit has been developed, which is easily re-configurable and adaptable to any vehicle architecture. The unit operates using software developed in-house to achieve a fully configurable vehicle control unit (VCU), intended to provide a rapid and cost effective platform for the development of demonstrator and small validation prototype vehicle fleets. The executable code is auto-generated from graphical Simulink / TargetLink models, which greatly reduces development time and risk of errors. The graphical source code also provides comprehensive documentation for users of the system. This paper describes the resulting vehicle control unit and gives details of the application of the unit within the plug-in hybrid demonstrator vehicle.

This paper, which is the fourth of a series, presents the REEV demonstrator vehicle developed by MAHLE Powertrain, which features a specifically designed range extender unit. The previous papers describe the specification setting, detailed design and the development of the range extender engine. A current production gasoline fuelled compact-class car was used as a donor vehicle and converted into a range-extended electric vehicle (REEV). The all-electric driveline specification has been developed to meet the performance criteria set for the demonstrator, matching the acceleration and maximum speed capabilities of the conventional donor vehicle. Also, a target electric only range has enabled the battery pack capacity to be specified. The resulting vehicle is intended to reflect likely, near to market, steps to further the wider adoption of electric vehicles in the compact-class passenger car segment.

The open MAHLE Flexible ECU (MFE) was developed and successfully implemented for controlling gasoline, diesel and hybrid engines. The increased demand of new functions development to address future powertrain challenges, such as lower fuel consumption, ever more stringent emissions legislative targets as well as the need to reduce development time and cost at the same time, led to the incorporation of the MFE functions in a co-simulation environment. The co-simulation environment consists of using the virtual engine developed with 1D or 3D numerical simulation tools and the functions of MFE developed with Simulink-Targetlink. This co-simulation approach allows modifying either the engine control or the engine itself. Regarding the engine control and its development, the existing and new functions were tested for the performance, emissions and behaviour changes on several production and prototype engines.

To improve the speed and accuracy of engine testing, the spark (gasoline)/injection (diesel) timing can be optimized based on the location of the 50% mass fraction burn point (α50) rather than the traditional approach of "sweeping" timing to find the most efficient point. Results from both gasoline and diesel engines show that setting α50 to around 8° ATDC gives optimum efficiency for most circumstances. An exception is the case of highly unstable combustion, where the misfire rate may also be strongly dependent on timing. For diesel engines this method is effective in finding the timing for best efficiency but in practice the chosen injection timing may be driven more by the need to optimize emissions. This technique has been implemented by incorporating a burn angle controller into the MAHLE Flexible ECU (MFE), a powerful and highly adaptable engine controller.