Talked about for decades, steer-by-wire is ready to be unleashed in the market, with German Tier 1 ZF moving to a front-of-the-grid position among key suppliers.
The advantages of the technology are numerous, from easier packaging and lower weight to more precise performance and improved safety; there’s no steering column to cause injury during a crash.
Several suppliers have introduced steer-by-wire products, including Bosch, Nexteer, Mando and others, but ZF will be among the first to have the feature installed in production vehicles.
Toyota will beat ZF to the punch, however, offering the technology as an option on its upcoming ʼ23 Lexus RZ450e and Toyota BZ4X battery-electric vehicles. Toyota’s steering system reportedly comes from keiretsu supplier JTEKT.
But ZF is expected to make up ground quickly, saying it will enter the market next year, having secured “significant volume contracts by multiple major car manufacturers…in all major regions.”
The deals will put ZF firmly among the leaders in the technology, the supplier says, adding it is in position to capture further market share in by-wire systems and “expects a significant share of the steer-by-wire market by 2030.”
ZF sees the technology as having application in both conventional and autonomous vehicles.
Steer-by-wire is a step up the ladder from electric power steering. With EPS, the hydraulic component is removed, but the traditional steering linkage remains. With SbW, the steering linkage also is eliminated and there is no longer a mechanical connection between the steering wheel and the steering gear. That forgoes the need for the steering column, freeing up space in the cockpit.
With SbW, steering inputs are transmitted from the steering wheel to a sensor-equipped electromechanical actuator positioned between the wheels. The setup allows for smaller steering wheels and greater flexibility in steering-wheel shape. In vehicles with part-time automated driving, SbW makes it possible for the steering wheel to be stored out of the way.
Multiple redundancies are built into the system, ZF says, including sensing – from the driver input (hand-wheel angle) to application of torque at the roadwheels – and multi-channel power electronics, as well as dual motor options for full system redundancy.
At its Next Generation Mobility Days event held in late May for customers and media at the M1 Concourse track in Pontiac, MI, ZF offered brief test drives in a Volkswagen ID.3 equipped with the steer-by-wire technology.
Three settings were demonstrated that allowed for easier parking-lot maneuvers at the base setting and then successively quicker response to be dialed into the steering feel as the vehicle went through a series of lane-change and slalom maneuvers at moderate speeds. The car performed much like any current vehicle with more conventional electric-power steering might. ZF says unlike today’s EPS, SbW doesn’t draw additional power to operate, meaning it won’t negatively impact electric-vehicle range.
The steer-by-wire setup makes it easier to manufacture both right- and left-hand-drive versions of the same model, and it allows wheels to be pushed out further to the edges of the platform, increasing interior room, the supplier points out.
“ZF’s smart by-wire systems end the era of mechanical connections and enable a new era of vehicle control,” CEO Wolf-Henning Scheider says in a press release. “ZF’s steer-by-wire technology brings new safety and comfort features, like autonomous emergency evasive maneuvers or parking in very confined spaces. It marks a breakthrough on the way to fully self-driving cars and trucks by adding new design and engineering freedom.”
