Design Con 2015

Touch control not always the best solution

-July 17, 2013

Recently Ford made a shift in their infotainment strategy by re-introducing the tried and true manual controlled knob to the driver's control. After a big push into the highly adaptable and configurable centralized touch screen with tablet-like operation, they ended up adding back in standard "radio knobs" to control the infotainment system. These do not remove the touch control, however - they supplement the features of the touch screen.

After a push toward using a highly adaptable and configurable centralized touch screen with tablet-like operation, Ford ended up adding back in standard "radio knobs" to control the infotainment system.

While the tablet-like interface allows the system to perform a large range of functions under software control, it requires more attention to operate. The infotainment system in a car has two conflicting tradeoffs - a need to be a single location for all the controls of systems in the car, and a need to be simple and straightforward to operate. The choice to move to a centralized touch display was the result that the single control method and location was the main factor for the driver.

The touch screen has the advantage of being multi-function and software upgradable, along with being specific and deterministic in function control. It has the tradeoff of requiring a longer portion of the driver's attention to use. Since it is integrated with the software on the screen, the selections and options require the driver to move his/her attention to the screen rather than the road.

The assumption that this would not be a problem was based on the idea that the controls and changes are made while the vehicle is not in motion, and that the time for the attention would not an issue. The reality is that quite a few of the changes in operation from this console happen while the driver is operating the car in moving traffic. In this situation, the need to look at the display and find precise positions for operating the touch control is a problem.

The solution is the use of a knob to perform the function. The knob has a rotating control function that can be operated without looking at it. It has both push-in/out control and rotational control that are methods of change that can be done with only a hand to operate. This allows the driver to continue focus on the road.

Unlike the touch screen that requires visual processing to determine the result of a touch selection, the knob uses other senses - for volume and station/track/selection it is simple and immediate sound feedback that indicates the result of the knob use rather than a visual. For temperature control, it is a whole body touch sense from the change in air temperature from the vents. These sorts of operations allow the diver to focus on driving and are part of the 100+-year car operation experience.

In the quest to add more features and functions, it appears the designers forgot about function and modes of operation as guidelines for the design. The need for simplicity over elegance is a key aspect for being able to multitask, as is the preference for adapting known skills (operating a knob without looking) rather than learning a new and unnatural skill set simply because it has that "cool' factor. This change is also going to drive other car manufacturers to re-think their software integration plans and focus on them more in the context of usability by the driver and as an augmentation to the driver's safety.

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