If you’re like most drivers, you probably glance at your mirrors every few seconds. In the next decade, however, that may change.
Increasingly, concept cars are popping up without mirrors. At next week’s Frankfurt Motor Show, for example, Kia is expected to roll out a sleek station wagon with no side mirrors. Similarly, Tesla earlier this year provided a glimpse of its Model Y crossover concept, which featured no rear-view mirrors. And BMW unveiled a mirrorless design on an i8 concept car in 2016.
BMW’s i8 Mirrorless concept uses two small cameras in aerodynamic holders, and a third mounted on the rear windshield. Images from the cameras are projected on a high-res display suspended from the front windshield. (Source: BMW)
“We’re looking for cars to have much lower drag in the near future, and mirrorless is a clear win,” noted Brad Duncan, senior director of Exa Corp., a provider of simulation software to the auto industry. “It’s a technology improvement and it’s an aerodynamic improvement.”
Indeed, Exa engineers recently studied automotive mirrors using their PowerFlow computational fluid dynamics software and concluded that mirrorless designs would improve the average vehicle’s aerodynamics by about 6%. If spread across all US vehicles, that improvement would save a stunning 145 million gallons of fuel every year, the company said.
“The environment needs innovation to meet our greenhouse gas goals,” Duncan told us. In contrast, today’s average car burns a full tank of fuel every year, just by transporting its mirrors, Duncan added.
Using CFD software, engineers at Exa Corp. concluded that today’s average car burns a full tank of fuel every year, just by transporting its mirrors. (Source: Exa Corp.)
Automakers know this, which is why many are experimenting with mirrorless concepts. In 2016, for example, BMW showed off its i8 Mirrorless concept, which uses two small cameras in aerodynamic holders, and a third mounted on the rear windshield. Images from the cameras are projected on a high-res display suspended from the front windshield. In a press release, BMW declared, “Dangerous blindspots have been consigned to the past.”
Automotive supplier Continental AG has also developed a system for replacing exterior and interior mirrors. The system uses three cameras inside the vehicle, along with two monitors that display rear and side views of the vehicle. The company claims that the system provides a wider field of vision and better visibility in poor light and rain. It also eliminates the problem of damaged exterior mirrors and reduces road noise, Continental said.
Government Approval Needed
Still, government approval is needed in order for automakers to take the concepts to production. In 2016, the US National Highway Traffic Safety Administration (NHTSA) approved the Cadillac CT6’s “hybrid” display from Gentex Corp., which combines a mirror and camera, but it has yet to bless a complete mirrorless design. Some engineers hope the agency will follow the lead of Japan, which last year approved rules to allow automakers to replace vehicle mirrors with cameras.
Government approval, however, is just one of the hurdles facing the technology. Some automotive suppliers believe the potential drawbacks of mirrorless technology aren’t yet fully understood and are calling on automakers and regulators to take a closer look before rushing to adopt it.
“There are definitely limitations to [electronic] displays,” noted Craig Piersma of Gentex Corp., which supplies mirrors and camera-based vision systems to the auto industry. “And sometimes automotive customers don’t even notice those deficiencies until they enter into an engineering development program.”
One problem with electronic displays is that they present a two-dimensional image, Piersma told us. More important, however, is the human eye’s need to readjust to an electronic display. “When you focus on a display, you’re focusing on a plane that’s 18 to 24 inches from your eye,” Piersma said. “But when you focus on the plane of a mirror, you’re actually focusing on the reflection, which is hundreds of feet behind you. So with a mirror, your eye doesn’t have to re-focus.”
That constant re-focusing becomes a problem for many drivers, Piersma said. “Most drivers look at their rear-view mirrors four to 10 times per minute, depending on traffic,” he told us. “To continually re-focus creates some eye fatigue.”
Software glitches also present a potential dilemma. If an electronic display fails on a mirrorless car, drivers could potentially be left without rearward vision. Moreover, display cost is an issue, too, especially in entry-level cars.
“As it turns out, a mirror is an incredibly effective way to see what’s behind you, and it’s relatively inexpensive,” Piersma told us.
Still, mirrorless designs are gaining momentum. Level 5 autonomous cars won’t need mirrors, and a growing number of vehicles already incorporate cameras on board, so mirror replacement is a natural consideration, experts say.
Continental’s Camera Monitor System employs three cameras inside the vehicle, along with two monitors that display rear and side views of the vehicle. (Source: Continental AG)
If replacement happens, many believe the side mirrors will be the first to go. “The protuberances are ugly, create aerodynamic drag, and their associated blind spots are the bane of parking-challenged drivers everywhere,” wrote The New York Times in 2016.
For those reasons, mirrors are increasingly being considered for extinction. “The high-tech leaders are going to push the envelope,” said Duncan of Exa Corp. “And then the status-quo OEMs and those who want to keep up will have to follow.”
Senior technical editor Chuck Murray has been writing about technology for 33 years. He joined Design News in 1987, and has covered electronics, automation, fluid power, and auto.
Code Quality Is Key to Securing the Connected Car
Join Jay Thomas, director of field engineering for LDRA, as he discusses the vulnerabilities of connected automobiles at the upcoming ARM TechCon, Oct. 24-26, 2017 in Santa Clara, CA. Thomas will describe recent hacks, and then walk audiences through the tools and techniques that can be used to protect future vehicles in a technical session, titled “Code Quality Is Key to Securing the Connected Car.” Register here for the event, hosted by Design News’ parent company UBM.