July 8, 2014
2015 Lexus NX dashboard, steering wheel, gauges showing fuel economy. Click image to enlarge
Article by Jacob Black, photos courtesy Lexus Canada
We live in an age where user experience, human-machine interfaces and digital touch technology are ubiquitous, so getting it right takes on greater importance than ever. Get it wrong – even by a hair – and the public will punish you.
And so more and more car makers are turning to external influences to make sure they get the UX right on their HMI.
UX is the industry jargon for User eXperience (because “X” is apparently sexier than “E”). HMI is how we refer to the interface between humans and machines – in this case a remote touch pad and some knobs. The key principles of good UX and good HMI are ease of use, intuitiveness, and the amount of focus they take away. The best practice is to minimize the effort and attention any given task takes to complete. Want to change radio stations? That should be one button/knob turn/gesture.
When Lexus built this system, designers focused on the separation of the display zone and the operation zone. The concept divides the cabin in a way that allows the driver to see what they need in one area while keeping their eyes on the road, and also control everything from the steering and pedal controls to the HMI without having to reach around the cabin. That’s one of the reasons Lexus has an available head-up display, and why the multimedia and navigation screen is set high and back in the dashboard.
Simply setting the screen a foot further back in the keyboard, we’re told, dramatically cuts the time a driver’s eyes take to refocus between the road and the screen – and at 20-30 metres/second, even a fraction of a second can be critical.
With the screen there it is easily visible in the “display zone” – but that makes it hard for a driver to access the screen as a touchscreen.
Lexus’s old HMI system also involved a screen and a remote control device. It wasn’t a touchscreen, all of the control happened via the mouse-like controller positioned just forward of an ergonomic wrist pad down on the centre console. The idea of the controller being in this position is that your arm naturally rests there when it’s not on the wheel. BMW, Audi, Mercedes-Benz and others all put their puck-style controllers there for that reason. But the mouse controller was skittish, the movements were ill-defined and the mouse cursor had to be monitored closely with your eyes to get the most out of it.
Enter the next-generation remote controller. In base trims, Lexus has this taken care of with a now-familiar puck-style controller. This one allows you to scroll through the menu items by turning the wheel, and pressing down on it selects the item you’re on. This poses an advantage when aiming for conquest customers familiar with the German brands’ HMI.
2015 Lexus NX centre console with new Remote Touch touchpad & Display Audio controller. Click image to enlarge
Additionally, there are hard shortcut buttons for selecting an audio mode, tuning a station or a track, and turning up and down the volume quickly. Getting back to the home screen or menu, or going back requires just one press of a regular hard button. That takes care of the simple, common radio and nav controls we’re all familiar with.
Automatic climate control is taken care of via its own, separate control centre and the drive mode selector also gets its own, well defined space. Drive mode is adjusted with a three-position dial.
In higher trims, Lexus has installed a haptic touchpad. It resides in the same position as the puck controller, but is operated with the fingertips. Drivers can use it to guide the “cursor” around the screen, press buttons on the screen, as well as scroll and zoom in on maps in the navigation menu by “pinching” the screen.
That sort of touch capability is more closely aligned with the sort of smartphone capability and laptop interaction that has become so familiar to many of us. Familiarity is another cornerstone of good usability. If a system is familiar, it takes less time to focus on, less time to analyze, and less time to complete tasks. That means more time for the important things – like making sure you don’t run up someone’s bumper in traffic.
So the same haptic feedback you get on your smartphone is present here. That way you know if your command has registered without having to wait for a response from the screen. The same pinch-and-zoom too, so you can quickly and easily access the information you need – like an expanded map view, without fiddling for buttons.
2015 Lexus NX gauges showing accelerometer, media information. Click image to enlarge
By bringing their cars more in line with the devices we use in our jobs, our social life and for our entertainment, manufacturers like Lexus help improve our connection with their vehicle. A good system will work wonders in that regard. We look forward to the opportunity to test such a system over a longer period to see if the learning curve is as short as we anticipate and the system becomes second nature in short order.