Today's automobiles are jam-packed with numerous sensors and warning systems to help drivers stay safe. Much of the feedback from such systems is provided visually, but there's so much going on that drivers may well be approaching overload. Researchers from Yale's School of Engineering have opted for a different mode of physical stimulus by installing tiny vibrating motors inside a driver's seat to advise of the approach of other vehicles.

Yale School of Engineering's Associate Professor John Morrell believes that there's already more than enough visual stimuli in a modern car. He also says that giving warnings in front of the driver of potential collision from behind costs crucial response time as well as unnecessary mental effort. Yale engineers have therefore developed a physical prompt system where vibrating motors and moveable cams send signals to the driver's back through the lining of the seat.

In the driver's seat

In a demonstration model, researchers interface a steering wheel and pedals to a computer driving simulator called The Open Racing Car Simulator, or TORCS for short. The driver's seat has 20 cellphone motor tactors (actuators that vibrate against the skin) arranged in a rectangular array across the back. A car approaching directly behind sets off centrally-located vibrators in the seat to offer the driver positional warning. Vehicles coming in at the left or right activate same-side warnings and as the car gets closer, the intensity of the vibration increases. A couple of cams on each side add to the sensation by exerting gentle pressure on the driver's rib cage when a car shows up.

Preliminary testing "showed that the vibrotactile feedback improved drivers' performance over that attained by using the rearview mirror alone" and also helped warn of vehicles hidden by the mirror blind spot.

Hopes for a safer future

The Yale study is not the only research looking at using physical prompts to pass information to drivers. Earlier research by General Motors and Dutch research organization TNO using tactile signals found that drivers could pick up directional navigation cues from a vibrating seat cushion while driving. It is hoped that the practical application of such research may lead to quieter yet more informative car interiors in the future.