At One with Lexus

The human-machine connection—Lexus style

03/31/2014—If you caught the last issue of Beyond by Lexus magazine (if not, get the magazine delivered to your mailbox; log on to your Lexus Drivers site profile page to do so), you may recall reading about your fellow Lexus owner Stephen Klein.

Klein, you see, is a digital user experience (UX) strategist, and his take on Lexus design is this: Lexus is the flat-out leader in making interiors that appeal to “interface-oriented creatives” such as himself.

In other words, Klein’s CT 200h doesn’t just look good; it’s been arranged with his driving experience in mind—even before it rolled off the line.

This got us thinking. Lexus has been pushing the envelope lately on the cockpit-design front—just take a look at that LF-NX dash below—so what’s the big picture here? What’s going on in Lexus design facilities these days to make superb UX happen?

Turns out, quite a bit.

Behind the scenes, Lexus engineers are talking a lot about Human Machine Interface, or HMI, the science of making drivers and cars act as one. Essentially, it means giving Lexus drivers intuitive vehicle control, optimized for “immediacy and ease-of-use.”

“We actually have a whole team of engineers specifically focused on human-factor issues,” explains Paul Williamsen, Lexus National Manager, Strategic Education Support for the International Market Enhancement Team. “These specialists meet with the chief engineer early in development to get an understanding of the car and driver, and then work to make sure they cook up the best kinds of user interface for that driver, for that car, and for the way it will be used.”

IN TOUCH
Okay, so how is that playing out in the newest vehicles coming to dealerships this year, like the RC, RC F, and LF-NX?

Perhaps the most striking UX development of late is Lexus’s new Remote Touch Interface: Vehicle systems will now be controlled by a touch-sensitive pad located in the center console, very much like a tablet or laptop touchpad.

In terms of HMI, the advancement here is that in the earlier mouse-style controller, the driver’s reference point was the elbow, naturally parked on the armrest. With the new touchpad, the driver can place their hand on the console and control systems with a single finger.

“Basically, we’re moving from an interface that uses the whole forearm to an interface that is all done with the fingertips,” Williamsen explains.

LINE OF SIGHT
Here’s another Lexus-HMI evolution: The upper display screen on the RC and LF-NX is set higher and deeper into the dash, as first seen in the redesigned GS in 2013. This placement is a great example of Lexus HMI at work, because it takes into account the physiology of human eyes as they shift between road and display.

“It takes an interval of time for your eyes to refocus from infinity to something that’s only three feet away, and vice versa,” explains Williamsen. “That is literally lost reaction time.”

Williamsen says that placing the display screen just a foot further away from the driver actually has an exponential effect on shortening the time needed to refocus.

“The math is very simple,” he explains. “If a car is going 60 miles an hour, that’s around a hundred feet per second. If we can save just a fraction of a second, that’s a couple of feet—perhaps the difference between drifting out of your lane or not, or hitting something or not.”

ASSURANCE
Another important element of Lexus HMI is confirmation—the way the vehicle assures you a command has been executed. Done properly, it should be effective but unobtrusive. Williamsen gives the simple example of an illuminated icon that indicates the defroster has been activated.

A more performance-oriented example is found in models equipped with Drive Mode Select (standard in the LS 600h). When the driver selects Sport mode—or Sport+ in the case of a vehicle with the F SPORT package—the instrument cluster illumination changes from cool blue to bright red. The LF-NX concept, shown below, takes this color shift to even greater levels:

“This color change confirms the change the driver has made in changing from normal to sport mode,” says Williamsen. “It lets the driver know they’re in sport mode, that they’ve told the car they would like different performance, and they can now expect a little more steering effort and different feedback.”

In short, it helps keep the driver aware of and in sync with the driving mode they’ve selected.

Of course, it doesn’t hurt that color change just plain looks cool. But in the end, says Williamsen, Lexus UX is about making a vehicle “feel right” when you drive it—whether you’re an expert in human-machine connections or just want to have a great time driving a premium automobile.