The future of steering is electric, but Kevin Ross, the vice president of Nexteer’s (nexteer.com) global steering business line, still sees viability for hydraulic steering technology in the next decade—at least in one segment.
“Hydraulics is at the end of its lifecycle from a passenger car perspective, but heavier vehicles—we’re talking three-quarter-ton pickup trucks, delivery vans, all the way up to Class 8 trucks—still rely on hydraulics,” he explains. “Why is that? Electric power steering at 12 volts can push only so much tie-rod load, so much force, and in those instances when you just run out of power, hydraulic systems are still predominant today.
So to work toward providing some of the benefits and capabilities that electric power steering (EPS) provides, Ross and his team developed Magnasteer with Torque Overlay (MTO), a first-of-its-kind system that uses a stepper motor controlled by a valve to allow the hydraulic steering to support electronic systems. The technology goes into production in 2015, according to Ross.
In addition to things like MTO, Ross is also focused on electric steering technology for passenger car applications. Looking toward the future of EPS, he says Nexteer engineers are working on how to further integrate steering with chassis control systems.
“EPS will continue to expand with features and functions, really getting into safety with collision-avoidance and autonomous control,” he says.
As steering becomes autonomous, at least during certain driving events like a skid or a lane drift, Ross argues that the technology will have to be safe up to “aircraft-type standards.”
Ross notes that a major challenge to widespread integration of driver-assist and active safety technologies with EPS is keeping the system efficient while saving weight to meet fuel economy standards without driving up costs.
As he looks toward the next decade, he says no one has yet developed the perfect steering technology to function autonomously and fully integrate driver-assist and safety technologies: “No one has the best solution, that’s what everybody is concentrating on today: How do we arrive at the lowest-cost, lightest-weight, most-efficient, safest system?” Ross asks. And presumably, they’re working to achieve it.—ZP