The commercial vehicle industry is adopting full-stability and collision mitigation technologies in ever-increasing numbers as it strives to enhance driver and highway safety. Full stability may soon be a mandated technology, as the final rule on the systems for Class 7 and Class 8 tractors is expected from the National Highway Traffic Safety Administration (NHTSA) in May 2015. NHTSA is also considering a Notice of Proposed Rulemaking around collision mitigation.
As part of its Bendix Tech Tips series, Bendix Commercial Vehicle Systems LLC offers maintenance guidelines for full-stability and collision mitigation systems.
Full-Stability Upkeep
Full-stability systems (the Bendix ESP Electronic Stability Program, for example) are also generically known as electronic stability control (ESC) systems. They use a number of sensors to address a tractor’s roll and directional stability. Additional sensors measuring driver intent and vehicle direction set ESC apart from roll-only stability – or roll stability control (RSC) – systems. As a result, full-stability systems recognize and potentially help the driver mitigate conditions that could lead to rollover and loss-of-control situations sooner on dry surfaces, and function in a wider range of driving and road conditions, including snowy, ice-covered, and slippery surfaces. When necessary, full-stability systems offer automatic brake interventions involving the steer, drive, and trailer axles. RSC systems typically apply the brakes only on the drive and trailer axles.
“The sensors and controls at the heart of an ESC system require little or no routine maintenance,” noted TJ Thomas, Bendix director of marketing and customer solutions, Controls group. “Drivers and technicians should familiarize themselves with the system’s service data sheets, so they know where to turn for explanations of trouble codes, as well as any diagnostic tools – in Bendix’s case, Bendix ACom diagnostics software. The physical components of an ESC system typically need attention only if certain aspects of the vehicle itself have changed.”
For example, if new steering system components are installed, the front end has been altered, or the vehicle has been realigned, the ESC system’s steering angle sensor will need to be recalibrated. This procedure is typically covered in service data sheets and supported using diagnostics software.
Similarly, if a vehicle’s tire size changes, the ESC system will need to be updated with the new tire values through its diagnostic support software.
The stability system manufacturer or vehicle manufacturer should be consulted in the case of more significant modifications, such as changing the wheel base, or installing or moving an axle.
Collision Mitigation Best Practices
Collision mitigation technology, such as Bendix Wingman Advanced – A Collision Mitigation Technology, is built on the foundation of ESC. This type of system uses a radar sensor mounted to the front of the vehicle to deliver both warnings and active interventions that can help drivers potentially avoid rear-end collisions, or at least help reduce their severity. Collision mitigation systems can provide distance and stationary object alerts and braking interventions, delivering up to two-thirds of the vehicle braking power through the steer, drive, and trailer brakes.
An important part of each pre-trip inspection is to check the vehicle’s radar sensor to ensure its field of view is free of debris and other obstructions. Aside from this important routine task, the components of a collision mitigation system require maintenance if trouble codes are active. If the front end of the vehicle sustains damage, follow service data sheet instructions to address possible alignment needs.
Don’t Forget the Wheel-Ends
As interconnected parts of a vehicle’s overall safety system, full-stability and collision mitigation technologies are optimized by properly maintained equipment throughout the system. Wheel-end inspection and maintenance – including brake stroke adjustment, lining thickness, and tire pressure and condition – remain crucial to safe vehicle operation.
Full-stability and collision mitigation systems do not replace the need for alert, safe drivers practicing safe driving habits, as well as continuous, comprehensive driver training. But properly maintained and operated, these technologies can help fleets and drivers in their ongoing efforts to operate more safely and efficiently.
Bendix provides commercial fleets, technicians, and drivers with the tools they need to ensure safe operation through assessment, maintenance, and repair. The Bendix On-Line Brake School at www.brake-school.com provides access to the company’s knowledge database and technical resources on all aspects of electronics and air brake maintenance and product education. The Bendix Brake Training School, one of the industry’s longest-running training programs, has educated more than 250,000 students since its founding more than 50 years ago. Among other tools, the company offers field-tested sales and service professionals; a 100 percent ASE-certified field technical support team; and the Bendix Tech Team (at 1-800-AIR-BRAKE), an expert technical support group providing service advice, brake system troubleshooting, and product training.