Abstract
During the drivetrain layout process new approaches have to be used in order to significantly reduce CO2 emissions. Especially for complex drivetrain systems, consisting of various drivetrain components, the layout has to be supported by simulation.
This paper presents a new approach for the virtual drivetrain layout using FEV´s “Drivetrain Optimization Tool” (“FEV DOT”). As an example a parallel hybrid drivetrain is laid out using this tool. Based on a combination of Design of Experiments (DoE), vehicle simulation and numerical optimization the approach of optimizing the powertrain with regard to minimizing CO2 emissions as well as improving the driving performance is presented. Parametric drivetrain models, built-up in the vehicle simulation tool “GT Drive”, allow a variation of the drivetrain components and the operation strategy. The coupling of DoE, vehicle simulation and numerical optimization in FEV DOT minimizes the simulation runs and enables to predict the response values (e.g. fuel consumption in various driving profiles, acceleration time 0 – 100 km/h) for every combination of the variable input parameters once the simulation is performed. The influences of the hybrid drivetrain components and the operation strategy on the response values can be directly analyzed. Furthermore, the drivetrain is optimized with regard to variable individual optimization goals. For the hybrid drivetrain, the trade-off between fuel consumption and driving performance is explained. The optimum drivetrain layout and operation strategy is presented based on minimizing the fuel consumption in three driving cycles as well as on improving the acceleration time.
Keywords: Drivetrain, Optimization, Hybrid, Integrated Approach