We’ve already seen systems that detect driver fatigue via steering wheel movements or by analyzing drivers’ faces. German engineering firm Hoffman and Krippner, however, has developed what its designers believe is a better alternative – a fatigue-sensing steering wheel add-on that tracks the driver’s grip.
The technology is based on the fact that when people drive and are reasonably alert, they’re constantly applying pressure to the wheel and/or moving their hands along it. If someone should fall asleep, have a heart attack or otherwise lose consciousness, that pressure will lessen and their hands will move less.
The actual device consists of a thin strip that’s applied to the inside rim of a manufacturer’s existing steering wheel, beneath the leather (or other) covering. That strip is made up of thin layers of foil, that have a weak electrical current running through them.
When pressure is applied and causes the layers to touch one another, it creates a short circuit between those layers, much in the same way that a resistive touchscreen works. A microprocessor keeps track of the intensity, frequency and location of those shorts, and uses it to establish a typical driving pattern for the user. When they deviate from it significantly, the car will then alert them to wake up and pull over.
Smart steering wheel detects driver drowsiness [Gizmag]