Volvo Dynamic Steering eases fatigue for drivers

November 2019

Tom Berg

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Volvo Dynamic Steering, an electric-over-hydraulic system that greatly cuts driver effort and claims to enhance safety, will be available on Volvo highway models early next year. The system stabilizes the vehicle in crosswinds and crowned and uneven pavement, helps maintain control in a front-tire blowout, and automatically returns the wheel to center during slow-speed maneuvering, officials said.

Used in Europe since 2013, the system has been adapted to North American steering gear and axles, and helps reduce driver fatigue and increase road safety, said Chris Stadler, a Volvo Trucks’ product marketing manager. Volvo Dynamic Steering, or VDS, will be an option in Volvo VNL and VNR models.

VDS uses an electric motor mounted on top of the hydraulic steering gear. Input from multiple vehicle sensors, at over 2,000 times per second, determine the appropriate steering wheel response. The system continuously monitors driver actions, environmental factors and road conditions literally faster than the blink of an eye, Stadler said.

The motor provides additional torque when needed to keep the truck safely on the road. This supports driver reactions with greater control and smoother maneuvering. In a failure of sensors or electrical circuitry, it reverts to all-hydraulic operation, he said.

First launched by Volvo Trucks in Europe, VDS works in diverse and changing terrains and automatically adjusts to handle any roadway condition. It can help drivers navigate unexpected situations, such as potholes and rapid tire deflations, adding up to 9 foot-pounds of torque in the steering column.

Key VDS features include:

  • Vehicle stability control keeps the truck moving straight on the highway while vibration from rough pavement is filtered out.
  • Return-to-center swings the steering wheel to the “neutral” position when the vehicle is maneuvering at slow speeds.
  • Lead/pull compensation provides a torque offset within the steering system to compensate for crowned roads, steady crosswinds and other short-term conditions that can affect handling.

With more controlled steering and fewer repetitive motions, drivers feel less fatigue, Stadler said. Testing has shown that VDS has the potential to cut muscular strain by up to 30% and for some specific motions, strain can be reduced up to 70%.

Driving VDS: Noticeably Easier

Demonstration runs on a track at Volvo’s customer center adjacent to the factory showed this reporter that noticeably less effort was needed to manipulate a steering wheel. Turns were smoother with less vertical movement by a truck’s front suspension. Backing a tractor-trailer also was smoother, and the return-to-center function happened with no driver input.

An intentional turn into and out of a shallow, concrete-lined roadside ditch took some effort with standard power steering, but was considerably easier with VDS engaged. We suffered no blown front tires, but here’s a tip if it ever happens to you: Immediately stomp on the accelerator to keep the truck moving, and you’ll easily control things until it’s safe to pull over and stop. I did it in a demo years ago with a big ol’ KW with manual steering, and it works – with a truck or car. Back to VDS: It was especially helpful at low speeds and while maneuvering in forward or reverse. The amount of assist is adjusted in four increments – 0 to 15 mph, 15 to 30 mph, 30 to 45 and 45 and up. The faster the road speed, the less the electric assist.

At highway speeds – not possible on the short dogbone track with its sharp turns – steering feel is similar to standard hydraulic power steering, our driver guides said.

Dynamic Steering complements Volvo road tractors’ existing limo-like ride and overall smooth operation, especially when a highly capable I-Shift automated manual transmission is part of the powertrain, it seems to me. But one claimed benefit, that it cuts shock transmitted through the steering wheel, was less meaningful to me because over the years I’ve learned to loosen my grip in the wheel rim while going over bumps and rough pavement.

Bottom line: I could get along without Dynamic Steering if I cruised on the interstates all day. But for local or regional duties where tight turning and up-and-back movements are involved, I’d want it. That depends on what it’ll cost, and at this event officials declined to state a price. LL