“OnGuardACTIVE Collision Mitigation System is enabled because of the communication bus,” he says. “OnGuard sends commands to the ABS system when it sees a potential crash scenario developing and commands a reduction in speed not only by commanding engine dethrottle, engine retarder engagement but also in braking via the ABS system connection if SmartTrac Stability Control is enabled, also because of the ABS system. When a roll or stability event is detected, SmartTrac commands select right or left side braking of the tractor and trailer to assist the truck and trailer in regaining stability.”
“Lane Keeping is a new feature in development, which will come about due to interfacing OnLane Lane Departure Warning System to ABS, allowing selective braking of right or left side of the tractor and trailer to improve lane keeping,” Lambie continues. “Electronically controlled air suspension ability to improve traction for 6×2 tractors with air suspension is enabled by the interface to the ABS system. When ABS detects wheel slippage, it communicates to OptiRide to safely transfer weight from the vehicle¹s non-driven [tag] axle to the driven axle by changing air pressures in the suspension air bags, putting more weight on the driven axle and thus improving traction.”
Lambie also notes that platooning will be enabled by all these systems working together, assessing and reacting quicker than a driver can to crash conditions ahead while allowing vehicles to operate in closer proximity to each other thereby improving fuel efficiencies and reducing congestion. Electronically controlled air dryer logic is planned to be loaded into the ABS ECU to bring another level of efficiency to the tractor.
Maintaining the systems
“The key is to follow the recommendations in the service data sheets, and resist the temptation to quickly ‘component swap’ when troubleshooting a system fault,” Bendix’s Weed says. “In other words, ensure all potential causes such as wiring issues are evaluated before components are replaced.”
Lambie says that the Meritor WABCO’s SmartTrac ABS, ATC and stability control systems do not require preventative maintenance. “It’s a buy it and forget it,” he adds. The ESCsmart feature, which is coming out in Meritor WABCO’s new SmartTrac system, is an intelligent/self-learning system that adapts to changing suspension and load conditions to ensure optimum performance not only when purchased new, but for the lifetime of the truck.
The bottom line
“Fleets have been specifying stability control systems in large numbers and at an increasing rate since 2005 even without the mandate,” says Meritor WABCO’s Lambie. Some facts: 22 heavy-truck rollovers occur on average every day in the United States (per FMCSA 2015 Large Truck and Bus Crash Data Pocket Guide) and rollover and loss of control crashes involving heavy vehicles are responsible for over 300 fatalities and 2,700 injuries annually according to FMVSS 136.
“ESC is a proven safety system achieving impressive safety statistics,” Lambie says. “NHTSA’s evaluation stated that the net benefit far outweighs the cost, which has also been validated by our fleet users. ESC systems could prevent 40-56% of un-tripped rollover crashes and 14% of loss-of-control crashes.”
“The benefits of the systems would save the industry $358 to $571 million by preventing crashes, fatalities, injuries, property damage and travel delays,” Lambie says. “NHTSA estimated the cost to the nation’s fleets to be approximately $45.6 million the net benefit of $312 to $525 million, far outweighing the cost of the system. Fleets report that they only require a 13% reduction of accidents to achieve breakeven, but they are achieving considerably higher results: 53 to 75%. One Meritor WABCO fleet customer reported rolling a vehicle every 16 million miles prior to SmartTrac. With SmartTrac, that fleet had not rolled a truck in four years. Another Meritor WABCO fleet customer reported the only rollover it had was when a gale force wind blew the tractor/trailer combination over. The bottom line is the reality of improved safety maintaining a high quality of life for the motoring public.”