elevated areas. Thus, drivers can feel and even press these elevated elements, allowing them to interact with the infotainment system. In a user study, Spies et al. compared a traditional, flat touchpad and the haptic touchpad. The results show that the haptic touchpad reduces the number and duration of glances to the screen and results in less lane deviation than the use of the traditional touchpad [ 8].

Even for traditional controls such as buttons or dials, first concepts propose to add more tactile feedback. Prototypes of these controls, called adaptive control elements [ 9], can change their shape to improve eyes-free usage in the cockpit (see Figure 3). These controls can be dynamically modified by reorienting the control or certain surfaces. Similarly, the control’s geometric shape can be modified (e.g., height and width change from a circular to a square control). Finally, the surface can be modified to transmit certain information.

 

March + April 2013

interactions

Tactile Automotive User Interfaces

One further option for haptic feedback in the car is provided by tactile interfaces based on vibration impulses. Such interfaces are already available, for example, integrated into the seat or steering wheel. These are part of advanced driver-assistance systems and may emit vibration impulses to inform drivers when they leave the lane unintentionally. So far, vibration output is used only to alert drivers of an event. However, a few research projects posit that vibration feedback can communicate more than just simple warning signals.

The navigation context seems to
be a promising application area, in
which complex information such
as distance to the next turn or
intersection could be encoded as
vibration signals. This would have
the same advantage as muting the
sometimes annoying audio output
of the navigation system (a common
practice among drivers), but would
not result in missed turns. The
vibration output can provide suffi-
cient information or may prompt the
driver to look at the display.