While some auto makers are wed to aircraft-like interiors with a switch or button for every control, there is a growing trend toward automotive cockpits dominated by a display screen of menus for such functions as navigation, telephone and infotainment.

BMW AG was widely criticized for its iDrive joystick system, introduced in the 7-Series two years ago, but the concept cars shown this year at the Frankfurt Motor Show amounted to industrial justification of the risk BMW took.

The big question is not whether to combine functions in a single display, but what sort of human-machine interface (HMI) should control the menu screen.

BMW's approach with iDrive, developed with supplier Immerson Corp., was a big knob with tactile feedback. The driver turns the knob to scroll through audio or climate control options and then activates the selection by pressing the knob.

Frankfurt concepts included the similar Nissan Dunehawk and the futuristic Toyota CS&C, which projects holograms of controls for the driver and uses sensors to capture his manipulation of them.

Johnson Controls Inc. showed a touchpad hidden under fabric, while Siemens VDO Automotive Corp. uses a touchpad on a big knob that lets a driver spell out destinations, text messages or telephone numbers with a finger.

The challenge is to provide the function of a computer mouse with minimal distraction for the driver. Voice control — the general solution a few years ago — was replaced this year by a variety of mechanical approaches.

“This is already an area of brand differentiation,” says Andreas Wlasak, chief designer at French interior supplier Faurecia SA. “People aren't trying to find the one and only way.”

BMW already has modified the iDrive for the new 5-Series, and the next 7-Series may add buttons to simplify menu manipulation, such as a shortcut to the homepage.

Audi AG developed a similar “Multi Media Interface” with supplier Harman/Becker Automotive Systems for the A8 and had it in the Nuvoli concept car in Frankfurt that is a stalking horse for the A6 replacement.

The Jaguar XJ display uses a touch screen so drivers can tap the radio station they want.

The tactile feedback in the BMW system, called haptics, was developed by Immerson in California and has been licensed also to many video game makers.

“Electronics has enabled the auto makers to create more controls, but drivers can become overwhelmed by the complexity,” says Joe DiNucci, an Immerson senior vice president. Adding touch to the control knob, he says, “dramatically multiplies the quality and quantity of information that the driver can process with confidence.”

Faurecia displayed its concepts for reporters at its new Hagenbach technical center in Germany. Its design approach is to divide systems into four areas:

  • Driving functions all controlled from the steering wheel.
  • Shared services such as navigation, telephone and entertainment controlled by the big-knob approach, with several buttons available as shortcuts to menus.
  • Three “hot buttons” for emergencies: warning flashers, medical alert and breakdown alert.
  • Personal comfort controls located on door panels for adjusting climate, seat position, window glass and, for the driver, mirrors.

“Our goal was to have some buttons for shortcuts, and offer the least number of menus possible,” says designer Isabelle Duchene, who led Faurecia's HMI study. “The radio was simple to organize this way, and at first the idea was to include the climate control, but we decided to disassociate it from infotainment.”

But, as Duchene notes, “not every customer goes that direction.”

Recent luxury automobiles, such as the Volkswagen Phaeton, have scores of buttons and switches. And volume-maker Renault SA cleaned up the center console in its recently launched Megane by moving functions to more complex switches on the steering column.

Even among concept cars, the idea sometimes is to be simple. The Opel Insignia large sedan hides all non-essential controls behind an elegant, sliding cover, as does the redesigned Lincoln Navigator.

Other HMI approaches shown at Frankfurt:

  • Toyota CS&S incorporates “spheres of information (that) seem to float in space, but when touched they allow the user to control functions,” the auto maker says. “Even users wholly unfamiliar with the equipment will find it simple to use.”
  • Mitsubishi Motors Corp.'s “i” menus are controlled by a semi-circular touch-sensitive track in the dashboard. Double-tapping the strip under one of several symbols brings that function to the display screen. Moving a finger along the track adjusts radio volume, for example.
  • The Ford Visos uses high-definition, next-generation Sony displays and a stick-like control in the console that moves left-right or up-down.
  • Siemens VDO's EasyControl system uses buttons as menu shortcuts, a knob that turns and clicks and a pad similar to a Palm personal digital assistant that recognizes handwriting.