Late in February, Bendix Commercial Vehicle Systems gave trucking trade press editors the chance to try out its ESP (Electronic Stability Program) tractor-safety system under wintry conditions at the MichiganTech Keweenaw Research Center outside Houghton, MI. The “tundra test” event followed up a warm-weather demonstration held for the media last summer.
This time out editors put a pair of Class 8 bobtail tractors through their paces with the ABS-based system — both switched on and off — over three different courses: a circular track with one iced-over and one packed-snow lane; a high-speed packed-snow field; and a large oval “ice rink.”
Despite all sorts of maneuvers inflicted on them — and by largely amateur drivers — the tractors remained fully within the drivers' control when ESP was engaged. As for how the system “felt,” it was clear to this reporter that just as the tractor's hold on the road began slipping, ESP was kicking in to “pull the truck” back from the edge of cohesion. Once the truck was where it should be in terms of its yaw and roll relationship to the road, full manual control was returned with no fuss whatsoever.
Richard Beyer, manager of technical sales, pointed out that ESP electronically provides yaw correction and roll stability to prevent jackknifing and other situations that can lead to rollovers by braking individual wheels and reducing vehicle speed as needed. “ESP is not meant to allow drivers to ‘push the envelope,’” Beyer told FLEET OWNER.
“Rather, the system is designed to help educate the driver,” he continued. “And the electronic speed reduction that is made automatically by EPS goes beyond what is needed to restore or maintain stability. That serves as a warning to the driver” not to exceed safe-driving limits.
Bendix will recommend ESP for all power units as it “addresses the full range of driving conditions,” noting that it is “especially critical for tractors pulling trailers with its ability to apply brakes to individual wheel ends… to counteract “trailer” push during maneuvers that may lead to loss of control or jackknifes on low to high friction surfaces.”
Offered as a “subset” to ESP will be the Bendix Roll Stability Program (RSP). Bendix said this system will engage brakes on all axles “to reduce vehicle speed below the critical roll threshold during maneuvers such as exit ramps and obstacle avoidance on dry high friction surfaces.” Bendix noted that RSP will be “an alternative primarily for high coefficient of gravity straight trucks.”
According to Beyer, Bendix showed the ABS-based system to the media now because it is in the “educational phase for OEMs and fleet customers.” Indeed, he said Bendix plans to stage 24 regional demos of ESP around the country this year.
Beyer added that Bendix ESP will reach the market next year. He noted pricing to end users will be determined by the various OEMs that will offer the system.
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