Overdrive Magazine | Trucking Business News & Owner Operator Info
Issue link: http://read.dmtmag.com/i/893962
52 | Overdrive | October 2017 ZF's latest steering system promises significant advances in autonomous technology, ease of driving and safety. The ReAx platform is a column-mounted electrically assisted hydraulic steering system that can be integrated with lane departure technol- ogy. The unit uses sensors to determine driving conditions and then controls an electric motor in the steering column to provide the appropriate torque feedback to the driver. While this makes the truck easier to drive, ReAx's most significant benefit is to improve safety, said Mitja Schulz, ZF's commercial vehi- cle general manager. ReAx does that by reducing the driver's workload. The steering wheel requires as much as 70 percent less effort to turn in a static state, reduc- ing stress and fatigue. It also improves safety by refining lane departure technology, which has been around for years. ZF has earmarked more than $200 million for auton- omous driving technologies. The company is working with about 50 customers globally on automated driving projects, including ReAx – "an enabler of autonomous behavior," Schulz said. But in the near term, ReAx functions more as a plug-and- play add-on for lane departure technology, including lane departure warning and ZF's Lane Keep Assist and Lane Centering Control. Lane Keep Assist combines ReAx precision steering with a camera system to determine lane markings. It provides steering correction assistance to reduce unintended lane departures and aid in colli- sion mitigation involving lane departures. Lane Centering helps keep the truck in the middle of its lane. According to ZF, more than 30 percent of all crashes are lane departure events. The average crash liability per truck via lane departure is $53,000. I took a Peterbilt 579 and Volvo dump truck, both equipped with ReAx, for quick spins at ZF's facility in LaFayette, Indiana. The ease of steering was staggering. With ReAx, I easily could turn the wheel with one finger while parked. Since the unit self-centers, you never have to guess when the wheels are straight again. ReAx enhances maneu- verability by controlling the steering system's response, providing better positional control. The ease of steering makes it easier to maneuver in tight spaces. The system shined brighter in a tight fig- ure-eight test when the truck glided through quick and deep left and right turns. ReAx launched in 2006 in the RV segment. Two years later, it was added to the bus market, where TRW refined the system's lower-speed maneuverability. When ZF acquired TRW in 2015, it widened ReAx's scope to include over-the-road trucks. A speed-proportional con- trol system, ReAx needs less driver input at low speeds in parking lots and tight spaces. It firms up at highway speed, when you would want more rigidity in directional stability. The learning system also compensates for road crown- ing and crosswinds by rec- ognizing when a driver has to hold the wheel off-center to account for the crown or consistently strong winds. The system will take some strain off the driver. With its ease of steering, ReAx also likely will play a strong role in driver recruit- ment and retention, said Mark Cartwright, ZF's global product planning manager. "It increases the size of the appli- cant pool, because traditional burly truck drivers are going away," Cartwright said. In third-party research during 2015, 97 percent of ReAx users rated its drivability as excellent, ZF says. ReAx precision steering works with lane departure and lane centering technology to help keep the truck in the middle of the lane. BY JASON CANNON ZF tech takes steering to new level The steering wheel requires as much as 70 percent less effort to turn in a static state. Artificial rumble strips warn of lane departure Hand-wheel torque urges vehicle toward lane center Hand-wheel torque urges vehicle toward optimal lane trajectory (Autonomous behavior) Hand-wheel torque urges vehicle away from lane boundary