IIHS finds misaligned bracket on non-OEM windshield impacts ADAS performance
Atlanta—Perhaps the most notable caution about non-OEM parts and proper calibration of advanced driver assistance systems (ADAS) came this summer not from automakers, scanning companies or collision shops, but the Insurance Institute for Highway Safety (IIHS).
Speaking at the Automotive Service Association-sponsored “Technology & Telematics Forum” during NACE in Atlanta, IIHS’ chief research officer David Zuby said his organization installed a non-OEM windshield in a Honda Civic equipped with automatic emergency braking. That system includes a camera sensor mounted in a bracket on the vehicle’s windshield.
“In this example, the bracket on the windshield was not aligned the way the OEM bracket was aligned,” Zuby said. “We noticed that it was rotated a tiny amount, less than a degree. And not only was it rotated, but there was play in the bracket. So the sensor itself could wiggle inside the bracket. We wanted to see the consequences of this.”
When IIHS ran a 25-mph test equipped with the OEM windshield, the Civic’s forward-crash warning alert sounded 3.4 seconds (and 38 meters) ahead of a potential impact. Depending on how the camera was misaligned within the play in the slightly rotated bracket on the non-OEM windshield, Zuby said, the warning alert did not sound until just 2.8 seconds (and 31 meters) prior to impact.
“The system’s emergency braking was initiated 1.5 seconds [before impact] in the baseline [with the OEM windshield], but as late as less than a second for the vehicle with the sensor most rotated out of alignment,” he said.
The result of that delay?
“While both the baseline and lesser-rotated sensors managed to avoid hitting the stationary car,” the test vehicle hit the stationary car at speeds of almost 5 mph in one test, and at almost 20 mph in another test when the camera was most misaligned within the bracket on the non-OEM windshield, Zuby said.
Another concern: Despite the camera’s slight rotation and play within the bracket on the non-OEM windshield, “the car did not throw a code,” he said. “It did not know the sensor was misaligned.”
Zuby said it wasn’t just the automatic emergency braking that was affected by the non-OEM windshield.
“We also noticed differences when the lane departure warning was issued,” he said. “Ideally, the warnings are issued just as you are crossing the [lane-marking] line. But we saw early warnings on the right side, and slightly late warnings on the left side.”
The early warnings before the vehicle was getting close to leaving the lane could lead annoyed drivers to turn the safety system off, Zuby suggested. Worse yet, he said, in the other direction, “We ended up almost a foot over the line before we got the warning.”
Zuby said the testing clearly showed “there are reasons you need to make sure that things are lined up properly, that they are calibrated properly, and unfortunately, the self-diagnostics in the system at this point aren’t going to necessarily tell you that they need to be calibrated.”
He also said in taking test vehicles to some local dealerships, the IIHS witnessed a technician failing to follow OEM procedures for the systems.
“Even within the dealer repair shop networks, some of the technicians are not yet up to speed on how to calibrate these things,” Zuby said.
Examining claims rates and ADAS
Zuby also discussed IIHS research into the impact that collision avoidance systems, when they are calibrated and functioning properly, are having on crash frequency. IIHS has been examining claims data for vehicles on which certain system, like forward collision warning or blind-spot detection, are optional features, comparing crash rates for those vehicles with that option to the same model without the optional systems.
The most significant impact has been on bodily injury claims frequency, the IIHS has found, with forward collision warning systems reducing bodily injury claims by more than 15 percent.
But the systems have some lesser impact on collision and property damage claims as well. Blind-spot warnings, adaptive headlights and forward collision warnings each have trimmed collision claims by 2-3 percent, according to IIHS data, and cut property damage frequency by 4-8 percent. Add in auto-braking with the forward collision warning, Zuby said, and property damage claims are reduced by about 13 percent.
The only crash avoidance system not proving to reduce claims significantly, he said, is lane departure warning.
But Zuby cautioned that any reduction in claims severity often “come with a penalty of claims severity.” In other words, there are fewer crashes, but fortunately for shops, those that occur result in more costly repairs.
“All of these technologies involve putting new sensors or fancy expensive headlights on the front of the vehicle, which are often damaged in crashes that aren’t prevented, and that’s adding to the cost of claims,” he said.
IIHS researchers, however, have also added in information from police reports to dial down further into crash data, and there the news isn’t as good for shops. The detailed crash information allowed the IIHS to examine how the different systems affected not just the vehicle’s claims experience overall, but the specific type of crash that each system is designed to prevent. In other words, rather than looking at the overall crash history for a vehicle with forward collision warning and auto-braking, did that vehicle experience fewer forward-to-rear collisions specifically?
“There we see really big reductions,” Zuby said. “When you combine forward collision warning with auto-braking, we’re eliminating about half of the front-to-rear collisions that occur.”
That could easily strike fear into anyone who has invested years or decades into a collision repair business. But Zuby also said that even though vehicle technology is changing rapidly, it takes a long time before any new crash-avoidance system is in a large percentage of the fleet on the road.
Rear cameras have been common in many new cars for years, Zuby cited as an example, yet won’t be in even 50 percent of cars on the road until 2021. Rear parking sensors will be in less than 40 percent of cars even three years from now. Forward collision warning will be in only about 20 percent of cars on the road in 2021, and auto-braking won’t be in even 7 percent by then.
“I don’t think we’re going to see five years from now that all of the cars on the road are replaced by self-driving vehicles, as some people have predicted.”