Seeking stability

by James Menzies

HOUGHTON, Mich. – This pretty, historic town located on the Upper Peninsula of Michigan is as good a place as any to demonstrate safety systems co-developed by Volvo Trucks and Bendix Commercial Vehicle Systems.

The Keweenaw Research Center affords the opportunity to put Volvo Enhanced Stability Technology (VEST) and Volvo Enhanced Cruise (VEC) through its paces in a harsh, yet controlled environment. It was here that a small group of truck journalists and certain Volvo customers found ourselves in mid-February for a demonstration of the latest Volvo safety systems.

VEST, an electronic stability system that intervenes when collisions are imminent to prevent loss-of-control and rollover accidents by dethrottling the engine and applying select brakes, has been an unmitigated success for Volvo. Introduced in 1990, VEST is now standard on Volvo trucks and in December 2010, the company put into service its 50,000th VEST-equipped vehicle. Frank Bio, product manager, trucks, with Volvo, proudly noted “We produce over half of the trucks out there with enhanced stability technology.”

VEST is useful because while some drivers are safer than others, no driver is perfect and there are certain instances where a driver deserves a second chance. Bio noted 93% of large truck crashes are chalked up to human error, and many of those could be prevented with a little intervention from an electronic stability system. On a blustery February day, we hit the icy, snow-packed surfaces of the Keweenaw Research Centre’s demonstration grounds to try VEST first-hand.

Safety VEST
I rode along with Jeff Drown, a Bendix test driver, in a Volvo VHD dump truck for a demonstration of VEST on a snow-packed circle track. While Volvo trucks don’t typically have an on/off switch for the VEST system, for demonstration purposes the trucks we were riding in were rigged with a toggle switch that allowed the driver to provide system-on and system-off comparisons.

We started out with the VEST system turned off and I was surprised – even in icy conditions – at how little effort was required to get us facing in the wrong direction. We had the track to ourselves on this day, but a similar scenario on the highway would be nothing short of terrifying.

“Once the truck starts coming around, I have to react right away,” Drown explained as we slid through a corner. “You can see how slick it is right here, it’s not responding at all.  We’re just at the mercy of the truck and it requires a lot more inputs, a lot more skill to keep it from going around.”

We did another lap with the system turned on and it was far less exciting, but in some instances, boring is good. With the system on, Drown was able to maintain control of the truck and keep it pointed in the right direction with comparably little steering wheel input. The comparison was night and day.

Adding VEC
Another system Volvo now offers is Volvo Enhanced Cruise (VEC), a collision avoidance system that warns a driver when a rear-end collision is imminent and, when cruise control is active, dethrottles the engine, applies the retarder and if necessary, applies the service brakes to prevent an accident. If the truck is equipped with an automated transmission – even the non-proprietary Eaton UltraShift – the system can even perform a downshift if required.

The interventions are accompanied by audible alerts, which work whether or not cruise control is activated. Until recently, VEC would only apply the brakes when the vehicle was in cruise control, but the newly added feature Volvo Active Brake (VAB) changes all that.

“Volvo Active Brake is the next evolution in the VEC system,” explained Fred Andersky, director of marketing for the controls group of Bendix. Volvo Active Brake is capable of applying two-thirds of the system’s braking power – up from one-third previously – through VEC, and it doesn’t require cruise control to be activated.

“It does the same thing (as VEC), but independent of whether or not cruise is on,” Volvo’s Bio explained. The feature will be offered in May and built into any new Volvo truck spec’d with VEC.

With Andersky behind the wheel and a brave soul piloting an ominously named “target” vehicle, we set out on the slick demonstration area to perform some maneuvers. Fortunately, the system worked as advertised, otherwise the folks at Bendix and Volvo would still be extracting pieces of SUV out of the front end of a blue VN780.

The target vehicle obligingly drove ahead of us as we travelled at 38 mph with cruise control activated. When the SUV slowed down, our VN did too, even though Andersky’s feet were clearly not on the brake. The truck we were operating was set up to provide alerts when our following distance fell below 1.5 seconds, but the settings are fully configurable.

When the speed of the vehicle in front of us picked up, the VN was able to resume its cruise speed without any driver input, as long as the service brakes weren’t applied.

Lights on the Volvo dash also provided a visual cue for drivers when a safe following distance was compromised, but it’s hoped drivers don’t have their eyes glued to the dash display. If they do, that could be the reason for the alert in the first place.

At slower speeds, drivers will receive only a single audible alert, an attempt to remedy frustrations over excessive alerts – a common complaint with Eaton’s Vorad system before it was acquired by Bendix and incorporated into its own system.

“Drivers got a lot of beeps on the old Vorad systems and they became background noise,” Andersky said.

Stationary object detection
Another feature incorporated into VEC is stationary object detection, which warns drivers when a metallic object has stopped in their path. It could be a stalled car or a random object, such as an appliance that has fallen off a vehicle.

In our case, an abandoned snowmobile served as the stationary object in our lane of travel. The system issues an audible alert that can provide up to three seconds of additional notice for a driver, allowing the driver to change lanes, ideally, or brace for impact in a worst-case scenario.

VEC is built upon VEST, to provide a complete active safety package.

“The (VEC) system is built on top of VEST for a couple of reasons,” Andersky explained. “First of all, when you build a collision mitigation system on top of a roll-only system, you’re not using all the brakes; you’re going to use the drive and trailer brakes but with a full stability system like VEST, you are going to use the driver and trailer brakes and also the steer axle brakes, so you get more balanced braking distribution and of course more braking power. We also do it because it’s not just about collisions. Drivers face all sorts of situations and accidents can be pretty complex. So, helping with rollovers, loss-of-control (accidents) and collision mitigation really makes this a very complete active safety package.”

Showing off ABS
In the final round of demonstrations, a Bendix test driver showed how effective ABS and traction control are when coupled with VEST on a split coefficient surface. For our purposes, a strip of asphalt was conveniently laid out alongside a patch of glare ice. With the ABS system turned off, we didn’t have a chance, and were pointed in the direction from which we came as soon as a subtle brake application was applied.

With ABS and traction control activated, not to mention VEST, the Volvo recognized it was on a split coefficient surface with asphalt on one side and ice on the other, adjusted the braking force on the sticky side accordingly and allowed us to come to a stop while still pointed forward. It was a remarkable demonstration, which highlighted the value of ABS and traction control.

It is difficult to participate in a demonstration of VEST and VEC and not be convinced the systems work as advertised and have the potential to reduce collisions. Still, they’re not free. While VEST is standard on Volvo trucks, there are some savings that can be had by removing it when ordering a new truck. VEC lists for about another $1,500 to $2,000, although the price, as they say, is negotiable.

To prove there’s real value in spec’ing the safety systems, Volvo has created a user-friendly crash cost calculator. Plugging in some rather conservative numbers and considering the average truck suffers 2.2 accidents per million miles, it’s clear there is a payback possible if the systems provide even a modest reduction in accidents.

“Even as little as a 10% reduction in non-injury crashes can pay for VEST and an air bag in less than three years,” Bio said. And that’s to say nothing of the injury – or worse, fatal – crashes that systems like VEST and VEC can conceivable eliminate.

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