COMET ? THE OVERALL VEHICLE CONTROL OF A MILD HYBRID VEHICLE FOR MORE COMFORT AND LESS FUEL CONSUMPTION

摘要

The COMET project of the Robert Bosch GmbH connects a new hybrid drivetrain to the thermal management system and a CO2 air conditioning system. The drivetrain consists of three power units, one engine and two electric drives with 8 kW power each, based on the 42V technology. An important part of the powertrain is the dual-E transmission, a power branching transmission with two planetary gears in combination with a twin shaft automated mechanical gearbox. Due to this fact it is possible to drive with continuous variable transmission and free-of-traction interruption. All engine auxiliaries were electrified, thus no more outer belt drive is necessary. For proving the possibilities of better driving comfort and reduction of fuel consumption two prototype vehicles, with gasoline and diesel engine, were assembled. After an introduction into the vehicle concept and the hybrid drivetrain this paper shows the system architecture for the overall vehicle control. The control structure of the COMET powertrain leads to the optimization problem with two degrees of freedom. The interaction of the aggregates during the real driving process, for the functions electric starting, hybrid driving and boost operation, were drawn into diagrams. Additionally, the results for the MNEDC test cycle have been represented.