Search Results

Hybrid vehicles are characterized by a combination of mechanical, electrical and control components. The complexity of this mechatronic system requires new methods and tools for a successful development of new hybrid vehicle concepts. It is now possible to accomplish certain tasks earlier in the development projects using virtual prototypes of the powertrain components and the vehicle. The process called “frontloading” integrates simulation, optimization and validation in earlier development phases of a vehicle and prevents from having cost intense problems in later development phases. Besides the reduction of emissions and fuel consumption also the subjective impression of the vehicle driveability are main goals for the optimization of hybrid powertrains.

In a fast and cost-efficient powertrain development process several 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, vehicle performance, functional safety and durability have to be validated on the engine test bed before integration and testing with real vehicle prototypes takes place. The integration of relevant control unit functions like transmission shift or vehicle stability as AUTOSAR software component into a simulation system at the engine test bed allows a fast and integrated workflow for series development. Complementary a high-quality combustion torque estimation and the consideration of driver behavior and lateral vehicle dynamics improve the correlation of simulated to real world driving maneuvers.

The reduction of CO₂ emissions represents a major goal of governments worldwide. In developed countries, approximately 20% of the CO₂ emissions originate from transport, one third of this from commercial vehicles. CO₂ emission legislation is in place for passenger cars in a number of major markets. For commercial vehicles such legislation was also already partly published or is under discussion. Furthermore the commercial vehicles market is very cost sensitive. Thus the major share of fuel cost in the total cost of ownership of commercial vehicles was already in the past a major driver for the development of efficient drivetrain solutions. These aspects make the use of new powertrain technologies, specifically hybridization, mandatory for future commercial powertrains. While some technologies offer a greater potential for CO₂ reduction than others, they might not represent the overall optimum with regard to the total cost of ownership.