SUNCAR iSUV BMW X5 – ETH Focus Project

The SUNCAR Steer by Wire project involved converting a BMW X5 to electric individual wheel drive with torque vectoring. In particular, a steer-by-wire control system was implemented. The torque vectoring served as a fault-tolerant fallback level for the steer-by-wire control.

With steer by wire, the mechanical connection between the steering wheel and front axle in a vehicle is eliminated and replaced by an electronic connection. This offers many advantages such as space savings, reduced risk to the driver in accidents, and the ability to control the vehicle energy-efficiently independent of the driver. To ensure this system continues to function even in the event of a technical failure, redundancies such as torque vectoring are necessary.

Torque vectoring technology controls vehicles through different torques at the wheels. Since the iSUV, unlike many other vehicles, has two individually controllable front motors—one for each wheel—this vehicle offers ideal conditions for this approach. At the front axle, in addition to the different torque, the resulting difference in precession force can also be utilized to turn the wheels in the steering direction during driving. This makes the system even more efficient.