External ADAS sensors can be knocked out of alignment when unrelated maintenance is being performed on a vehicle — body work or windshield replacements, for example. Have technicians follow up those repairs by recalibrating any sensors that may have been affected.  -  Photo: Bendix

External ADAS sensors can be knocked out of alignment when unrelated maintenance is being performed on a vehicle — body work or windshield replacements, for example. Have technicians follow up those repairs by recalibrating any sensors that may have been affected.

Photo: Bendix

No good deed goes unpunished, the saying goes, and that’s kind of the case with advanced driver-assistance systems, commonly known as ADAS.

These new safety technologies encompass a new generation of driver assistance aids, such as anti-rollover warning systems, lane-departure warning systems, active cruise control, and collision warning and mitigation systems. Lidar, radar and camera systems can help with front and rear vehicle tracking as well as blind-spot warnings.

ADAS are increasingly integrated with other systems, as well as the vehicle itself, to create a suite of systems that work together and with the truck itself to help keep drivers alert and safe.

The American Automobile Association’s Foundation for Traffic Safety estimates that advanced truck safety technologies, including lane-departure warning systems, automatic emergency braking, air disc brakes, and video-based onboard safety monitoring systems, have the potential to prevent up to 63,000 truck-related collisions a year. It also stands to reason that spec’ing trucks with these technologies would provide a powerful defense against expensive legal verdicts and settlements in the wake of an accident involving commercial vehicles.

But lawyers who target truck fleets in accident litigation have found an end-run around the ADAS defense in the courtroom. During a session at last fall’s meeting of the American Trucking Associations’ Technology & Maintenance Council, ominous warnings emerged. During the discovery phase of a trial, lawyers are increasingly requesting fleet maintenance records to verify that any ADAS on vehicles involved in crashes were properly maintained and calibrated. If the fleet can’t provide documentation proving those procedures were done before the truck left the shop, lawyers allege improper maintenance and negligence on the fleet’s part contributing to the accident.

That’s a very real financial and legal imperative for fleets to establish set guidelines for ADAS maintenance and document any inspections, repairs or adjustments made to them.

The good news is, because these are largely self-diagnosing systems, there’s not a lot of additional work that typically goes into inspecting ADAS and verifying they are performing properly.

“I call ADAS ‘self-reporting’ systems, actually,” says Chuck Brodie, service team leader for ZF. “Many times, you just need your technicians to take the truck for a test drive after working on it and check for any ADAS fault codes during that drive, and then note what they saw — or didn’t see — on the repair reports.”

Properly maintaining and calibrating lidar, radar, and camera sensors will become even more important as autonomous control systems become more commonplace on commercial vehicles in the future.  -  Photo: Jack Roberts

Properly maintaining and calibrating lidar, radar, and camera sensors will become even more important as autonomous control systems become more commonplace on commercial vehicles in the future.

Photo: Jack Roberts

The Human Angle

Beyond the legal aspect, ADAS maintenance can affect driver acceptance. This technology is still fairly new, says Fred Andersky, director of demos, sales and service training for Bendix. Building driver buy-in and confidence in the systems is still in the initial, trust-building stages.

“If the system is not maintained properly, when it comes time for it to be needed, it won’t be as effective in helping the driver mitigate a situation as if it were properly maintained,” Andersky explains. “This can also hinder driver acceptance of the technology when the system performance does not meet expectations.”

In addition, he says, depending on the system, a malfunction indicator light on the dash could result in a driver refusing to drive the truck, which means a load doesn’t get delivered and a customer is not satisfied.

Another ADAS concern has been tampering by drivers, Brodie says, although this problem has lessened somewhat as the systems become more commonplace and accepted in the driver community.

“In the early days, there were a lot of cases of drivers tampering with camera systems, in particular,” he says. “And we saw a lot of attempts to change settings on following-distance sensors and collision mitigation systems because some drivers didn’t like the setting or the ‘feel’ they got while driving.”

If you suspect a driver has been attempting to alter ADAS settings, Brodie says, simply accessing the fault code history in the system can usually reveal when changes were made and allow them to be corrected.

It’s also important to think about the technicians you have working on ADAS, he says, as these systems are a departure from traditional vehicle maintenance.

“I think one of the most important things fleets need to do is seek out and hire techs with strong electronics backgrounds,” he says. “These components are a different beast from conventional moving engine parts. They are typically solid-state electronic components. Having a solid understanding in CAM networks – particularly J1939 and other common systems — is a plus, as well.”

Suppliers such as ZF offer specific training on ADAS maintenance and calibration, which means truly understanding how these systems build upon one another and function together.

“Let’s say you’re getting feedback from a collision mitigation system,” Brodie says. “You’ve got to have someone who can determine the root cause of the issue. It might just be a driver insisting on following too closely. It might be a sensor out of adjustment. Or you might have a problem with the active cruise control system or in the [automated transmission] itself. To make that determination accurately, you’re going to need a technician who can get into the vehicle’s fault codes and diagnose the issue properly.”

The National Institute of Automotive Service Excellence is working to develop advanced driver-assistance system testing and certification so the industry can have confidence in the skill level of technicians working on ADAS.

The Importance of Sensors

The need to install the sensing devices for ADAS around the periphery of the vehicle makes them vulnerable, says Ben Johnson, director of product management at Mitchell 1, a provider of repair information software. Sometimes simple maintenance tasks require moving a sensor or camera out of the way while a repair is made. Or the vehicle can “nudge” something on the road, slightly warping a bumper or grille that has a radar unit or camera mounted behind it.

For instance, if windshield glass is replaced and there is a camera mounted behind that windshield, re-calibration may be required. Or if the vehicle is re-aligned and the thrust angle is affected, the forward-facing camera and/or radar system may require calibration.

Likewise, if any of the “black boxes” that control the ADAS are removed and reinstalled to allow access to other components (radiator, A/C condenser etc.) calibrations may be necessary.

Johnson stresses that any time a vehicle is maintained in such a way that these devices are moved, or any time there’s an impact that might have warped or shifted a sensor, ADAS sensors should be rechecked to ensure proper calibration.

“Any action that could relocate one of these sensors, even by a very small amount, can require re-calibration to ensure it’s still sending information to the computer which is accurate,” Johnson says. “If a critical sensing device becomes shifted and not re-calibrated, the vehicle could act abnormally, causing a safety issue.”

That kind of miscalibration can result in warnings and emergency braking when a truck approaches an overpass because the radar interpreted the overpass as an object (presumably another vehicle) being rapidly overtaken by the truck.

“We’ve also seen systems erroneously indicate an imminent collision because the forward-facing radar was skewed a little to the left,” Johnson says. “As vehicles in the oncoming lane were approaching, the system deduced they were in front of the truck and a collision was imminent.”

These miscalibrations are “double risks” for fleets. The driver has to deal with a misbehaving safety system that’s incorrectly interpreting oncoming traffic. At the same time, the system may not be identifying the real vehicles the truck may be overtaking.

When events like this occur, driver confidence in these systems wanes. They may even try to disable the systems.

In a worst-case scenario, problems caused by miscalibration can contribute to the causes of a collision — negating the effort to improve safety by installing them in the first place.

8 Common ADAS Maintenance Issues

  1. There are a number of common maintenance “bugs” that arise with advanced driver assistance systems, according to Fred Andersky, director of demos, sales and service training for Bendix. They are:
  2. These systems build on the antilock braking and stability technologies. A fault with the ABS system or ESP system will mean the ADAS system won’t be available.
  3. Many ABS issues tend to be wheel-speed sensors, which are susceptible to chassis harness issues such as rubs and chafing and also can be damaged when service is done at the wheel-end. The sensor may become non-functional, a wire may be severed, or a sensor may not be close enough to the tone ring.
  4. For stability control, the steering angle sensor may fall out of calibration. This can sometimes happen after a front-end alignment, so it’s important to calibrate the sensor after any work done on the front end.
  5. A rare, but sometimes reoccurring issue, can be the incorrect placement of a lateral acceleration/yaw rate sensor after work on the frame rail or chassis modifications. If this sensor is moved or not returned to the correct orientation, this may cause a fault in the stability control system.
  6. Faults can be caused by road conditions or terrain. Sometimes these can be cleared by restarting the vehicle. If the fault returns after restarting, then the truck needs to be taken to a qualified repair facility as soon as possible.
  7. Small video cameras that are a crucial part of many systems can malfunction. Make sure the camera is connected/plugged in. Chassis wires that are frayed, cut or improperly repaired may create problems, so check the chassis harness first for non-obvious issues.
  8. If the windshield is replaced, the camera needs to be placed in the same position and using the correct bracket as the original OEM installation.
  9. Camera blindness is usually a temporary, self-correcting occurrence due to sun and fog. However, if the camera is blocked by something, such as a large bug over the camera, this will cause problems. The fix is typically removing the obstruction or correcting the camera mounting position.

This article first appeared in the March 2022 issue of Heavy Duty Trucking.

[Editor's Note: This article was updated on March 16 at 1:53 p.m. to correct the spelling of ZF Service Team Leader Chuck Brodie's last name.]

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