Abstract
Keywords: Powertrain, Hybrid, Simulation, Testing, HiL
In a fast and reliable powertrain development process manifold optimization and validation tasks are required at early development stages, where prototype vehicles are not available. Especially for hybrid powertrain concepts the development targets for fuel consumption and vehicle performance have to be validated before vehicle integration and testing takes place. Up to now this frontloading concept was utilized either with Hardware-inthe- Loop Systems (HiL) or with dynamic engine test beds. At HiL systems one or many control units like ECU (Engine Control Unit), TCU (Transmission Control Unit) or VCU (Vehicle Stability Control Unit) are connected with real-time simulation models. The models can be easily changed in order to simulate different engine and vehicle configurations. The fuel consumption can only be simulated using measured maps. At the engine test bed the torque load is precisely controlled with a highly dynamic dynamometer. The actual fuel consumption and emission is measured with high accuracy and reproducibility. The presented approach uses an innovative coupling of a HiL system with a test bed automation system under real-time conditions. This allows the manual or fully automatic virtual driving of either real world situations or legal emission cycles within the same test environment. The paper describes the application of this new method for conventional and hybrid vehicle development and shows the benefits of integral testing for fuel consumption and vehicle performance targets already at early phases in the development process.