Next Spring, Mercedes-Benz will release a new driver-assistance system called Attention Assist that can recognise driver fatigue. Mercedes say scientific studies indicate around 25% of all serious accidents on motorways are caused by overly-tired drivers, an accident cause more significant than driving under the influence of alcohol.
Attention Assist monitors the driving behaviour of the driver, generating an individual driver profile which is constantly compared to a flow of sensor data. This allows the system to discern the driver’s transition from alertness to drowsiness and provide a warning in time for him to take appropriate action.
In addition to the vehicle speed and linear/lateral acceleration, the system also registers steering wheel movements, indicator and pedal operation, plus a number of specific control operations and external influences such as side winds or uneven road surfaces.
Mercedes say monitoring the driver’s steering behaviour has proved to be particularly relevant, as an overtired driver has difficulty in keeping the vehicle precisely on track and makes minor steering errors which are often quickly corrected in a characteristic manner.
The heart of the system is an extremely sensitive sensor that enables the steering movements and their speed to be monitored precisely. During the first few minutes of each journey, Attention Assist uses the data to compile an individual driver behaviour pattern which is constantly compared with the current steering behaviour and driving situation by the onboard electronic control unit. This enables the system to recognise the typical signs of over-tiredness and warn the driver accordingly. This is done by an acoustic signal and a display in the instrument cluster.
Top Lexus models are available with a system that monitors the driver’s head position to detect inattention.