Advances

AWD software helps boosts electric drive performance

Electric drive systems benefit from advances in software control and system integration for all-wheel drive vehicles

The quality of the systems integration, how well the software controls in different vehicle systems work together, is a big part of any hybrid or electric vehicle’s driving experience. Software control for an all-wheel drive (AWD) or electric drive system governs more than just the traction: it directly influences the vehicle dynamics, the CO2, the complete driving experience.

For hybrid all-wheel drive, on vehicles such as the Volvo XC90, the software control must also take care of details like the damping of any noise or vibrations, determining the quality of the system integration and drivetrain optimisation.

The majority of the software work is the integration into the automaker’s E/E system, the electrical and electronic architecture of the vehicle. System integration is about understanding the vehicle and optimising the role of driveline systems in the overall driving experience. It also means having specific controls to help the dynamics experts overcome adverse effects like NVH.

Integration also engages additional functionalities, such as the disconnect device used in eAxle systems for hybrids. This enables the decoupling of the motor and rear axle from the wheels at higher speeds when electric propulsion is not needed. Disengaging eliminates direct torque losses and prevents harmful overspeeding of the motor.

Engaging and disengaging the electric drive smoothly and noiselessly takes specific know-how. The control strategy needs to speed up the prop and align it with the wheel speeds.

It’s similar to ActiveConnect systems for all-wheel drive. A lot of GKN Automotive’s electric drive control capabilities build directly on its all-wheel drive expertise. That’s why the company is often first-to-market on high-profile programmes like the Porsche 918 Spyder, BMW i8 and Volvo XC90.

Having this software and control expertise in-house has enabled GKN Automotive to emerge as a leading player in AWD and eDrive systems in recent years. It helps its engineers work more effectively with other suppliers on programmes: to understand what is behind the interfaces in a system; to be able to discuss technical challenges in more depth, and to find better solutions.