Before engineers dreamed of eliminating drivers in cars, they imagined eliminating the side mirrors. The protuberances are ugly, create aerodynamic drag, and their associated blind spots are the bane of parking-challenged drivers everywhere.
But now, a long-sought solution looks closer to finally stripping cars of their Mickey Mouse ears, as many automakers demonstrate video systems that replace side mirrors with cameras.
Continental, a major parts and systems supplier to automakers, calls them digital mirrors.
“There’s significant noise reduction, and there’s potential for CO2 reduction because of reduced drag and improved fuel economy,” said Dean McConnell, director of customer programs for advanced driver assistance systems at Continental. “There’s also the increased field of view.”
In a customized Mercedes-Benz CLS, Continental demonstrated how its system would work. Thumb-size video cameras on the exterior of the car replace the side-mounted mirrors and use interior screens on the left and right side of the dashboard to deliver views of what is next to and behind the car.
The screens are near where a driver would normally look to check a mirror, and the camera views are wider than what a physical mirror can provide, eliminating blind spots along the side of the car. The cameras, which can automatically adjust to reduce glare from sunlight or increase brightness at night, are also helpful in tight parking spots.
“No matter where someone stands behind you, you can see them,” said Philipp Hoffmann, BMW’s project manager for camera monitor systems, as we backed up in a crowded parking lot during the International CES consumer electronics show in Las Vegas last month.
We were in an exotic-looking BMW i8 sports car with tiny cameras on stalks instead of side mirrors. Together with a camera just above the rear window, the three views can be displayed on a high-resolution monitor that replaces the rearview mirror. A glance up gives the driver a picture of what is beside and behind the vehicle.
Mr. Hoffmann pushed a button and the rearview monitor image transformed into a virtual panoramic rear view that electronically stitched all three camera pictures into a seamless image. The resulting live image made it appear as if nothing was behind the driver to obscure the view.
Mr. Hoffmann also demonstrated how the video cameras, which can recognize and gauge the speed of objects around the car, can be tied into automatic braking, parking and collision systems to protect the driver and the i8’s glossy finish.
Because of the potential benefits, other technology suppliers, like Valeo and Visteon, are also keen on mirrorless systems and hope that regulations requiring old-fashioned physical mirrors will be amended.
Almost two years ago, the Alliance of Automobile Manufacturers and Tesla Motors petitioned the National Highway Traffic Safety Administration to allow video cameras to replace side mirrors. The Auto Alliance estimates that external mirrors, depending on their profile, account for 2 percent to 7 percent of a car’s aerodynamic drag.
Mr. Hoffmann said he expected to begin road testing of the mirrorless systems in Europe this year, quickly followed by additional testing in Asia. He remained hopeful that the United States would follow suit soon.
He may have good reason to be optimistic. Daimler AG, parent company of Mercedes-Benz, is already testing a couple of autonomous tractor-trailers in Nevada that use large high-definition screens instead of side mirrors. And BMW recently received an exemption from the Transportation Department to allow it to deploy an automatic parking feature that enables a BMW 7 Series car to park itself, while the driver stands on the curb. It is a feature the company demonstrated only a year ago.
Rearview cameras provide a precedent. Those that eliminate the blind spots directly behind vehicles are already deemed a significant safety improvement and will be mandatory in cars and light trucks in the United States by 2018.
“But there aren’t any definitive studies of side cameras,” said David Zuby, chief research officer at the Insurance Institute for Highway Safety.
Mr. Zuby said the closest example of how effective such systems might be is a survey by the institute of Honda’s LaneWatch feature available on models like the 2016 Odyssey.
LaneWatch uses a camera on the passenger side to give the driver a video view in the dashboard screen of the right side lane whenever the turn signal is activated. Mr. Zuby said there was a correlation between the LaneWatch system and a reduction in accident insurance claims, although further study was needed.
Using cameras instead of physical mirrors could also end dangling damaged mirrors. To replace a typical mirror, which features built-in defrost, turn signal and blind spot sensors, can be expensive, as much as $946 on a 2015 Acura RLX, according to the insurance institute. Mr. McConnell at Continental noted potential savings in building cars that no longer need the structural support for side-mounted mirrors.
Still, the mirrorless demonstrations from Daimler, BMW and Continental show that the systems will present a challenge to drivers. Unlike other safety systems that are installed and applied without the drivers’ knowledge or input, like electronic stability control and airbags, digital mirrors require training and practice to use.
Looking up into the rearview mirror, for example, to see what is beside you in the BMW i8 is not instinctive for a driver trained to perform shoulder checks.
“Yes, it may require some driver training,” Mr. Hoffmann acknowledged. Further refinements need to be worked out, too. The BMW’s panoramic video mode has a slight fun-house mirror effect, for example. .
On the other hand, having a single panoramic video view may be an improvement over the combination of old and new technology now deployed in cars that use a rearview camera and traditional side mirrors.
Demonstrating the problem, in one of the first Chevrolet Volt cars, a General Motors employee backing up the car in a Manhattan garage during a test drive tore off a side mirror. The employee had been focusing solely on the rearview camera screen and forgot to check the side mirrors.