Key to the Mobility of the Future From 2026: Steer-By-Wire Technology from ZF Goes into Series Production at Mercedes-Benz

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Steer-by-wire technology enables precise driving maneuvers, high stability and safety, as well as optimal responsiveness in software-defined vehicles. It also allows for the use of new steering wheel geometries and cockpit designs. After ZF's steer-by-wire system was already implemented in the Nio ET9, Mercedes-Benz will also start integrating the technology into its vehicles from 2026.

Compared to traditional steering systems, steer-by-wire eliminates the mechanical connection between the steering wheel and the steering gear. The steering force is generated by a mechatronic actuator between the wheels. The steering commands are transmitted by a steering wheel actuator in the cockpit, which is equipped with a rotational angle sensor.

A torque feedback unit replicates the natural steering feel and road feedback. The redundantly designed ZF system adjusts the steering ratio individually, so that the ratio of the steering wheel angle to the wheel angle is optimally varied depending on driving speeds or situations: a direct ratio for increased agility during parking and an indirect ratio for stability and comfort at higher speeds.

Thanks to the technology, the cockpit and interior can be designed more freely, providing more space for passengers. New steering wheel geometries or foldable steering wheel rims are also possible. The elimination of the steering intermediate shaft means that no components need to be routed from the interior to the engine compartment. This simplifies assembly, the positioning of steering elements, and the adaptation of platforms for different model series or markets with right- and left-hand drive. Additionally, the absence of the steering intermediate shaft minimizes noise transmission and enhances passive safety.

Furthermore, steer-by-wire forms the basis for driver assistance systems. While mechanical steering systems cover ADAS functions up to Level 3, steer-by-wire enables functions up to Level 4. These also include future active safety functions such as Automated Emergency Steering (AES).

Minimize Costs

Another advantage of steer-by-wire is the purely software-based adjustment of steering and thus driving behavior. This means that no mechanical special designs are required for different models and configurations. This not only increases production scalability and cost-effectiveness but also simplifies chassis calibration and shortens development and assembly times. In the cockpit, even more driving modes can now be made freely selectable to respond to the respective driving situation.

Twin-Worm Concept

Driving a vehicle has so far been an exchange between the driver, the car, and the road. Accordingly, the feedback received on the steering wheel is crucial for safety. The Torque Feedback Unit developed by ZF with the "Twin-Worm" concept combines the bandwidth for generating feedback and steering precision with a compact design and a high torque-to-volume ratio.

In the twin-worm unit, two worm drives, which can be separately controlled by the software, are used to jointly generate feedback and steering feel for the driver. On one hand, the system is redundantly designed; on the other, it allows for highly precise control.

Friction and play within steering systems are crucial factors that contribute to the perception of comfort. In the ZF Twin Worm System, these parameters are not represented mechanically with additional elements like springs and damping components but are implemented through software-based control. The steering ratio, and thus the maximum steering wheel angle, can be widely varied and can even be reduced (into the range of 180 to 210 degrees), enabling new, flatter steering wheel designs. As a result, repositioning the hands while steering is no longer necessary. Since the system fulfills ASIL-D requirements, it is compatible with automated driving functions up to Level 4.

EasyTurn: Agile With front-Axle Steering

Thanks to the group's expertise in steer-by-wire, the EasyTurn front axle strut system is significantly improved. With EasyTurn, the maximum turning angle of the front wheels doubles from 40 to 80 degrees—for a typical mid-size car, the turning circle shrinks from over ten to under 23 feet . With steer-by-wire technology, these maneuvers are made maximally comfortable. The system's variable ratio enables maximum agility when maneuvering and turning, as well as precise steering behavior during normal driving. EasyTurn is suitable for small city cars, delivery vehicles, and people movers in urban environments.

Collaboration With Mercedes-Benz

ZF has already received several series production orders for its steer-by-wire technology, including from Mercedes-Benz. Together with the automaker, the supplier worked on developing a specific solution, marking its first European customer. In 2026, series production of a corresponding vehicle will begin in Europe for the first time. "With our system expertise in steering, we enable vehicle manufacturers around the world to fully unleash the dynamic potential of their models," proudly announces Philippe Gasnier, Head of Research and Development at the ZF Division Chassis Solutions.​(se)

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