eTestHiL

Development of test methods for electrified heavy-duty powertrains based on multiphysics hardware-in-the-loop test benches

One focus of the eTestHiL research project is to explore the possibilities of purpose design in the development of electric drives for heavy commercial vehicles (HDV). For this purpose, the eTestHiL starts with requirements gathering for current HDVs, followed by parallel chassis and powertrain design that will be built and tested in the final phase of the project.

A crucial challenge in the development of new powertrain systems is the packaging space available in the vehicle and determined by the chassis and the supporting body structures. While connection points to existing structures have to be taken into account during development of conversion design drive axles, a purpose design should adapt the installation space exclusively to the electric powertrain.

Within the data acquisition, driving data are collected from real truck journeys and made available for further use in the project via a cloud solution. Based on the real driving data, requirements and load spectra that were derived from other sources and used for chassis and powertrain development will be validated. For the purpose of data acquisition, a non-invasive measurement concept is under development in order to record various data relevant to the drive and chassis on the selected routes, such as:

• Route information, performance and driving profile data (speed and acceleration)
• Dynamic wheel loads, transfer function between road and body

In parallel, a novel electrically driven axle for a 42-ton truck is being developed and built as a prototype for validation measurements later in the project. One focus of powertrain development is to further research into the potential for efficiency increase through decouplable transmission sides and the implementation of innovative control strategies for multi-engine powertrains. In this context, a suitable method for both shifting and coupling control optimisation and optimisation of power distribution between the e-motors is being designed and further researched. The axis development is complemented by a methodical investigation of the interaction between motor and transmission, e.g. with regard to package and efficiency. Hence, transmission concepts for different e-motors are developed, pre-designed and evaluated as a whole in order to determine the most suitable one. Based on the simulation results, a concept is selected and fully 3D-designed; followed by comprehensive efficiency measurements completing the development and concept validation.

Simultaneously, a research on the innovative chassis concept is carried out as part of the Chassis Development work package to meet the increasing efficiency requirements for HDVs. Literature research and benchmarking analyses will be used as a starting point to identify potential for further reducing the fuel consumption of modern commercial vehicles. Based on these findings, various axle kinematics will be developed to specifically reduce driving resistances of the drive axle without compromising driving safety or comfort. For the sake of concept validation, a prototype with a geometry similar to that of large-scale production will be designed, manufactured and then comprehensively tested on the ika chassis test rigs.

To meet the increasing requirements on the efficiency of the vehicle, an innovative chassis concept is being developed in the Chassis Development work package. Literature research and benchmarking analyses will be used to identify potential for further reducing the fuel consumption of modern commercial vehicles. Based on these findings, various axle kinematics will be developed to specifically reduce driving resistances of the drive axle without compromising driving safety or comfort. In order to validate the selected concept, a prototype with a geometry similar to that of large-scale production will be designed, manufactured and then comprehensively tested on the ika chassis test rigs.