Stuttgart. Whether with milk and sugar, black, whether brewed or espresso, from a large pot or in a tiny cup: coffee has fans all over the world. And the Germans love it too. On average, Germans drink around 164 litres of coffee each per year. As a homage to these aromatic beans, the International Coffee Organisation (ICO) has proclaimed today to be International Coffee Day. Mercedes-Benz also uses the wake-up effect of coffee: ten years ago, Mercedes-Benz presented the drowsiness warning system ATTENTION ASSIST as a world first. This assistance system can recognise typical signs of fatigue and prompt drowsy drivers to take a break. The intuitively recognisable symbol for this is a stylised coffee cup in the instrument cluster. ATTENTION ASSIST is now standard equipment in all Mercedes-Benz car model series. More than 14 million vehicles featuring it have already been delivered to customers.
"Take a break" could not be more simply and internationally understandably illustrated than with a coffee cup," says Klaus Frenzel, head of UX Design, who is responsible for the design of the user interfaces in Mercedes-Benz vehicles. "The friendly nature of this prompt is another positive aspect. After all, our vision is to provide a comprehensive experience in the car. We want drivers to feel completely at home. It is also important that the complex digital world is made as easy as possible to understand."
"Preventing stress-related accidents and improving driver fitness safety is one of the major thrusts in our safety development," says Dr Michael Hafner, head of Driving Technologies and Automated Driving. "Assistance systems like ATTENTION ASSIST, which support the driver, make their contribution to this." In 2009, Mercedes-Benz presented the drowsiness warning system as a world first and introduced it as standard in the E and S-Class. It is now standard equipment in all the brand's passenger cars. It is therefore on board much sooner that legally prescribed: from 2022, all new cars in the EU must have such as a system.
In Germany, over-tiredness is the cause of around 0.7 percent of all accidents with personal injuries, and of around 1.2 percent of all accidents with fatalities, according to 2018 figures from the German Statistical Office. To date Mercedes-Benz has delivered more than 14 million vehicles equipped with ATTENTION ASSIST to customers, and in the GIDAS accident database, no accident by a Mercedes-Benz model with over-tiredness as the cause has been recorded in Germany since the introduction of the system as standard.
How ATTENTION ASSIST works
In 2009, Mercedes-Benz introduced ATTENTION ASSIST as an assistance system that recognises typical signs of drowsiness and gives a warning. The system's sensors observe the driver's behaviour and can recognise – especially on the basis of steering wheel movements – if the driver is becoming drowsy. If the system detects corresponding signs, it emits an audible warning signal and flashes up an unequivocal message on the display in the instrument cluster: "ATTENTION ASSIST. Break!" ATTENTION ASSIST is now active at speeds between 60 and 200 km/h.
ATTENTION ASSIST measures over 70 parameters and evaluates them to detect drowsiness. This continuous monitoring is necessary to register the transition from wakefulness to drowsiness and to warn the driver in good time. Based on this wealth of data, ATTENTION ASSIST calculates an individual driver profile during the first few minutes of every trip. This profile is then compared with the current sensor data and the prevailing driving situation by the car's electronic control unit. As well as speed and longitudinal/lateral acceleration, the system also registers e.g. indicator and pedal operation, as well as external influences such as crosswinds or road undulations.
Over the course of several years of development and testing with ATTENTION ASSIST, steering behaviour has proved to be a particularly telling indicator for the level of drowsiness. During tests with almost 700 car drivers, Mercedes-Benz scientists found that overtired drivers have difficulty in staying precisely in lane. They make small steering errors which are often corrected quickly and in a characteristic manner. This effect can already occur in an early phase of drowsiness – usually before dangerous micro-sleep sets in.
 Study by the German Coffee Association: "How Germany drinks Coffee 2018"
 GIDAS stands for German In-Depth Accident Study. GIDAS is a cooperative project between the Federal Highway Institute (BASt) and Forschungsvereinigung Automobiltechnik e.V.