While waiting for the traffic lights to change, your correspondent notices a pair of red warning squares appear on the windscreen. They follow a couple of pedestrians as they cross the road directly ahead. Another warning, this time farther in the distance, highlights a third person, harder to spot, stepping out from behind a line of waiting cars. On the move again, a road to the right is illuminated in blue to indicate the turn suggested by the satnav. A local landmark also gets a name tag attached as it passes by.
This realistic test is of a head-up display (HUD) produced by Envisics, a firm based in Milton Keynes, just north of London, and one of the leaders in “augmented-reality” displays for vehicles. These work a bit like the virtual-reality headsets worn by computer gamers, except they do not require the user to don any elaborate accessories. Though HUDs have been available in some cars since the late 1980s, producing two-dimensional images on the windscreen directly in the line-of-sight of the driver, this version has far greater clarity because it is holographic. In other words, it produces three-dimensional images with height, width and depth that appear to be part of the view of the road ahead.
Holographic HUDs are likely to represent the future of car design. Apart from being able to clearly provide information on navigation and a vehicle’s performance, moving images that pick out warnings of any dangers in the road ahead offer a promise of safer, distraction-free driving.
The very first HUDs were much simpler. In the second world war, some fighter pilots flying Spitfires benefited from an image of a gunsight reflected onto a screen in their line of sight. As pilots don’t have time to look at an instrument panel in the intensity of a dog fight, the innovation has spawned generations of successors. Modern fighter jets use much more sophisticated HUDs which provide both targeting and flight information.
HUDs for land-based vehicles have similarly been growing in capability. They began by simply replicating bits of the dashboard display, such as a speedometer and turn signals. More modern versions can make use of a vehicle’s cameras and other sensors to identify potential hazards, like a cyclist in the road ahead. Holography allows three-dimensional images to move with any hazards, appearing closer or farther away as the view changes. This provides visual depth clues which help a driver understand more clearly what a vehicle’s safety systems have detected, says Xiaoxi He of IDTechEx, a firm of analysts.
Displaying such information directly in front of a driver also reduces the need to look down and refocus on a touchscreen, which is increasingly seen as a distraction that can result in accidents, adds Dr He. As a result, she expects a combination of smart display-features and enhanced safety will help drive the market for automotive HUDs to over $10bn by 2034, growing at a compound annual growth rate of 24%.
Envisics, which has its roots in holographic research carried out at the University of Cambridge, is backed by companies that include General Motors (GM), Hyundai, Jaguar Land Rover and Stellantis (whose largest shareholder part-owns The Economist’s parent company). The firm’s new HUD is due to appear later this year in the Cadillac Lyriq, an electric SUV produced by GM.
The technology itself is cutting-edge. Earlier HUDs mainly produced two-dimensional or stereoscopic images using liquid crystal or LED projectors on the dashboard to create an image reflected on the windscreen. Envisics’s new system uses three miniaturised lasers, producing the primary colours of red, blue and green, controlled by a customised processing chip and lots of software to produce moving holograms. Among the challenges the company faced was making the device small enough to fit on the dashboard, yet sufficiently powerful to produce bright images which can be seen by a driver in direct sunlight. This was not easy, says Jamieson Christmas, Envisics’s boss, which is why the system is covered by over 1,000 patents.
It will be up to carmakers to choose what kind of information they display holographically, although there is clearly a limit to what can be presented on the windscreen. For one thing, holographic displays could assist with the growing use of vehicle automation, which is still some way from the widespread adoption of full “hands-off” autonomy. Greater levels of visual information would be better at alerting drivers when and why they need to take back the wheel while using features like intelligent cruise-control.
Talk, don’t touch
Touchscreens could also be enhanced by the use of HUDs. As more and more controls move from physical switches to cheaper touchscreens, concerns are growing that fiddling around with screen icons and sub-menus can be dangerously distracting. The addition of voice-activated controls can help keep a driver’s eyes on the road, although spoken commands can be misunderstood, which often results in drivers looking at a touchscreen to find out why. That can be avoided if a spoken request is confirmed with a HUD message.
As HUDs continue to get smarter, though, there are some in the industry who wonder if they might one day replace touchscreens altogether. Future motorists, whether or not they need to take the controls at all, might simply operate their vehicles by engaging with a hologram.
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