Study: Next Generation Touchpad with Haptic Feedback Makes Control Tasks Easier and Safer

* Test study at University of Kassel shows clear advantages of a touchpad with active haptic feedback
* On average, 23 percent less time spent with eyes off the road and 33 percent shorter input time during a standardized lane-change maneuver
* Improved sight-free operation with this new human-machine interface in the car helps increase driving safety

Babenhausen/Kassel, Germany - How do you make the growing number of safety and convenience features in a vehicle easy to operate so that the driver is distracted as little as possible? Answers to this question are among the core competencies of the international automotive supplier Continental. Its experts in the human-machine interface (HMI) in vehicles are currently pursuing a new path: they have developed a touchpad with active haptic feedback.

This is an input device with a touch-sensitive surface and its primary purpose is to control screen menus. The ingenious feature of this touchpad is that it confirms a driver’s action with tactile pulses – similar to what you would experience with a button. “We see a lot of potential in touch control. Together with active haptic feedback, the touch principle is particularly efficient. This is confirmed in a test study carried out at the University of Kassel,” says Eelco Spoelder, Manager of the Continental business unit Instrumentation and Driver HMI during the VDI Conference “The Driver in the 21st Century” in Braunschweig/Germany.

“The touchpad with active haptic feedback demonstrated a significantly positive effect in the study,” says Prof. Ludger Schmidt, Head of the Human-Machine-Systems Engineering Group in the Mechanical Engineering Department at the University of Kassel. “On average, a driver’s gaze is diverted away from the traffic 23 percent less when haptic feedback is switched on. And the control tasks set were performed on average 33 percent quicker than without active haptic technology.”

These values were investigated using a driving simulator. The 32 study subjects had to perform standardized lane-change maneuvers in accordance with ISO 26022. At the same time, the drivers were expected to call up and activate functions from the screen menu using the touchpad.

Performing secondary tasks at the wheel can significantly affect driving safety. The longer the driver’s gaze is directed at the screen, the longer the vehicle is being “driven blind.” The detailed results of the study were presented at the 10th Berlin Human-Machine Systems Workshop.


Haptic Feedback makes for operating safety

The touchpad with active haptic feedback was positioned low down within reach of the right hand. Its purpose is to operate a screen on the center console. This split between screen and operation avoids hand-eye coordination with an outstretched arm to control a menu using the finger. Instead, the driver’s finger, supported at the wrist, glides across the touchpad without the driver having to see it.

As relevant fields are reached on the screen menu, they are optically accentuated – in a similar way to a cursor. At the same time, the touchpad produces a tactile mechanical pulse when a menu field is reached – also known as a haptic search. If the driver presses the touchpad using a certain amount of pressure while a menu field is selected, the instrument confirms this input with an active pulse. “This process means that there is virtually no risk of a driver inadvertently pressing something,” explains Andreas Brüninghaus, head of concept development for haptic controls and center consoles at Continental in Babenhausen.

The touchpad with active haptic feedback is a new element of the human machine interface in the vehicle, according to Brüninghaus. “It supplements Continental’s existing human-machine interface strategies, which also include the active accelerator pedal and the head-up display, for example. The greatest possible benefit to drivers will be an holistic HMI concept that supports drivers in their tasks in many situations. The touchpad with active haptic feedback is an efficient enhancement of the operating options.”