Higher stability

Aug. 1, 2005
DEMAND has been strong for Freightliner's Roll Advisor & Control safety technology in heavy-duty vehicles, company officials said at a June press conference

DEMAND has been strong for Freightliner's Roll Advisor & Control safety technology in heavy-duty vehicles, company officials said at a June press conference in South Bend, Indiana. The company has installed almost 11,000 systems since beginning production approximately two years ago.

Equipment from one customer — Praxair — was highlighted at the press event. The processor and distributor of gases and related products ordered Roll Advisor & Control systems on 150 tractors operating out of the Praxair facility in La Porte, Indiana.

“We haven't totally eliminated rollovers, but we made a significant reduction in the total number,” said Mark Tietje, Praxair director of safety for North America Industrial Gases. “Praxair has a profound commitment to safety, and we want a zero accident level. We've calculated that a rollover costs us a minimum of $150,000.

“Driver acceptance of the roll stability control system has been very good. They recognize the system as an improvement, and it has heightened driver awareness of issues that contribute to rollovers. These issues include distracted driving and fatigue.”

Developed in cooperation with MeritorWABCO, the system alerts the driver to a potential rollover and/or automatically slows the truck to reduce the risk of an accident. The Freightliner Group provided perspective on customer acceptance of the Roll Advisor & Control technology at an event to announce new capabilities at the company's Test Engineering operation in South Bend.

“We are committed to exploring and developing technologies that have the potential to enhance heavy-duty truck safety,” said Michael von Mayenburg, Freightliner Group senior vice-president of engineering and technology. “We are pleased that so many customers have adopted Roll Advisor & Control, which is a highly useful and cost-effective system, and we expect acceptance to continue to grow.”

According to the Department of Transportation, rollover crashes can account for about half of the annual heavy-duty truck driver fatalities. Roll Advisor & Control is designed to alleviate truck rollover by teaching drivers to recognize risky vehicle maneuvers or to reduce the forces pushing the truck toward rollover.

The system has two integrated components: Roll Stability Advisor and Roll Stability Control. Both utilize sensors integrated into the truck's antilock brake system. By tracking the truck's lateral acceleration and wheel speed, the system detects the potential for rollover.

Driver aid

Roll Stability Advisor is a training aid designed to advise the driver that he has operated the vehicle in near rollover conditions.

Warnings are communicated via the Driver Message Center, an easy-to-read display located in the dash, directly in front of the driver.

The Roll Stability Control function takes rollover avoidance to the next level by automatically slowing the vehicle. When sensor data indicate that a rollover is imminent, Roll Stability Control sends a signal to reduce engine power, apply the engine brake, and/or apply the tractor rear service brake. This slows the truck and reduces the forces pushing the vehicle toward rollover.

The trailer brakes will also be momentarily applied to assure that the combination remains stable and is slowed as rapidly as physically possible while remaining stable. When the vehicle becomes stable, power is restored and the engine brake is turned off.

The system may also be installed with just the Roll Stability Control function. It is available on certain heavy-duty vehicles manufactured by Freightliner Group brands.