Next-Generation HMIs Should Accommodate Human Behavior
By James M. Amend WardsAuto.com, Oct 21, 2008 6:11 PM

DETROIT – Experts at the Convergence Transportation Electronics Conference here agree the safest next-generation human-machine interfaces will include a reconfigurable display with touch-screen controls and seamlessly integrated nomadic devices, such as iPod music players and cellular telephones.

They also say designers of new HMIs must consider the driver’s most basic needs, as well as enhance driver performance and stimulate driver enthusiasm to improve safety.

This means designers must enhance the user-friendliness and reliability of the HMIs to eliminate distraction, says Ralph Bruder, of Germany’s Darmstadt University of Technology.

Driver-assistance systems are one way to help motorists, who will continue to insist on adding cell phones and portable music players to the systems’ primary task of operating the automobile, he says. But drive-assistance can have a reverse effect, as well.

“Sometimes, assistance features can confuse drivers even more, leading to information overload,” Bruder says during a session on the role of HMIs.

For example, Bruder cites a Darmstadt study where German drivers lost confidence in traditional adaptive cruise control where the posted speed limit fell to 19 mph (30 km/h) and below. However, when the drivers moved from a vehicle with an instrument panel display to one with heads-up display, their confidence increased.

Bruder also examined instances where an intuitive HMI improves safety when too little information exists, such as a fatigued driver on an empty roadway. Using a roadside, pop-up barrier, the exercise determined one-third of participants never applied braking or steering to avoid the object.

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But when an avoidance-assistance system provided braking and steering inputs, an overwhelming number of drivers managed to avoid the barrier. Yet, when asked if they felt assistance from the vehicle, more than half claimed they performed the maneuver entirely on their own.

“Believe me, they did not,” Bruder says. “So autonomous driving, if it is done in this intuitive way, could help when the information load is low.”

Next-generation HMIs also should make driving more pleasurable by stimulating driver enthusiasm. Bruder points to a reconfigurable instrument panel and iPhone or iPod-like features, where users draw satisfaction from performing a task that makes them feel part of a community.

Gesture-based technology could lead to the perfect HMI auto makers find so elusive, he says. The technology responds to gestures, rather than touch or speech. It’s most notable application is the Wii wireless controller from video game maker Nintendo.

Gert-Dieter Tuzar, principal designer-HMI at Johnson Controls GmbH, agrees that interior designers must be mindful of driver behavior. He emphasizes reorientation, or the split second during a task, such as checking gauges, when the driver quickly checks back with the roadway. Reorientation also occurs when the driver’s eyes return to the task inside the cabin.

Both are examples of when drivers are under the most stress, he says.

One easy fix would be to reduce cross-display searches by clustering certain gauges together on the IP. “Everything is plus-sized and within the sightline,” he says.

Tuzar also suggests a more seamless integration of nomadic devices, such as cell phones and MP3 players. “The nomadic device is recognized by the system, and you access the content as you are used to (doing).”

He suggests that HMI designers consult with colleagues in fields such as ergonomics, mechanical engineering and industrial design as they work on next-generation HMIs, and warns researchers to reconsider what they classify as primary and secondary tasks.

“From my observations, the moment a secondary task becomes important to the driver, (it) becomes the primary task,” says Tuzar. “And the primary task of driving becomes secondary.”