The complex system keeps track of several indicators of driver alertness to help assess when the driver is becoming too tired to drive. By observing the driver throughout each trip, the computer develops a profile for each individual and uses that profile as a baseline for analysis of alertness. When the computer senses a significant deviation from the profile, it compares that deviation with known signs of tiredness and the trip length, time of day and driving style. If it thinks it is appropriate, it will warn the driver of his or her tiredness.
Data collected by the system is also incredibly intricate and detailed: everything from longitudinal and lateral acceleration to steering angle, use of indicators and pedals, road surface and wind conditions are measured and compared to arrive at a judgment about the driver’s level of attention. Steering input is apparently particularly indicative of tiredness, as a specific set of inputs and corrections are common to drivers as they near sleep. The warning given when the system deems it necessary is both audible and visual, with a symbol in the instrument panel suggesting the driver pull off and rest.
Mercedes-Benz sees the new Attention Assist system as a complementary system to its numerous other safety technologies such as brake assist and traction control. Billed as the first system of its kind, the Attention Assist feature is scheduled for availability in Mercedes-Benz cars in 2009.