EcoBEV – A (Tested) Powertrain Concept for Energy-Efficient Driving

Current electric production vehicles often have one electric motor per driven axle, which allows targeted, active wheel torque distribution on the two wheels of the axle via the intervention of the brake. This makes it possible to improve the self-steering behaviour and, thus, among other things, driving safety.

Alternatively, electric motors can also be coupled directly to the wheels via half shafts. If this is done on all four wheels, the potential of active wheel torque distribution can further be expanded. Scientific studies show that this can also minimize energy requirements. However, these studies are mostly based on simulative results obtained under idealized conditions.

Figure 1: Real and virtual BEV with four electric motors for energy-efficient driving

Project Goals

Therefore, the aim of the project is

• Understanding the influence of torque distribution on energy consumption of over-actuated electric vehicles (4 electric engines and all-wheel steering)
• Demonstrate the potential for improving the energy efficiency of different torque distribution strategies on a driving test bed

In the first phase, the focus was on the design and construction of a suitable experimental platform (moving test bed) and the development and analysis of a driving function for active torque vectoring to minimize energy consumption while taking driving behaviour and vehicle safety into account. In the second phase, tests on dry, wet and slippery road surfaces will be performed with the test vehicle to demonstrate that intentionally significant improvements in current drive concepts for electric vehicles are possible even under realistic constraints, for example, limited accuracy and availability of measurement data and vehicle parameters, and with the usual computing power of the control unit.

Figure 2: Drivetrain design and integration

Researcher

• Daniel Klein

Project Funding

FFG/Klima und Energiefonds (KR20ZM0F17958)

Project Partner

• STARD