In Sindelfingen Mercedes-Benz peers into the future. Tests in virtual conditions provide critical insights for future production vehicles.
The Mercedes-Benz S-Class has been driving for over an hour now. Starting in Sindelfingen, the car is to travel about 650 kilometers to Bremen, located in northern Germany. Five hours of travel remain as the night slowly creeps in. The motorway is fairly empty, the S-Class has settled at a crusing speed of 120 km/h. Only occasionally does it need to overtake another car (activate the indicator, move over to the left-hand lane and then merge back into the right-hand lane). This is the only entertainment program; the sound system is silent, the phone has been switched off, and the passenger seat is empty. The drive is becoming increasingly monotonous. The vehicle drifts out of the lane several times. Does the driver perhaps need a break?
Cut to the Mercedes-Benz driving simulator in Sindelfingen. This is where the journey is taking place – not on a public road. And yet, the journey feels very real. The driving simulator is a tool used in the development of passenger cars and commercial vehicles. Its advantage: systems and components for future Mercedes-Benz models can be tested in isolation for any phase of the development process. Here, drivers can approach their physical limit without being at risk themselves. The information gathered helps engineers at Daimler learn about the acceptance and operation of new technologies.
To actually reach those limits or even surpass them without facing any risks is only possible through the driving simulator.
Today ATTENTION ASSIST, the attention assistance system widely used in Mercedes-Benz vehicles, is being tested. "The objective is to learn more about the limits of the current system in order to make the next generation of ATTENTION ASSIST even more efficient," Werner Bernzen, Project Manager in the Mercedes-Benz Vehicle Development department, explains. "To actually reach those limits or even surpass them without facing risks is only possible through the driving simulator. If an accident does occur, the drivers may be startled momentarily, but nothing happens to them. This is why the driving simulator is so important. It would be too dangerous in real traffic."
A group of test subjects comprising men and women of all ages and with different degrees of experience
Today’s task: drive for as long as you can until you get tired. For this reason no distractions are permitted for the virtual journey to Bremen. Bernzen and his colleagues assembled a group of representative test subjects, comprising men and women of all ages and with different degrees of experience behind the wheel. Each test person should drive for as long as possible. Sensors and video cameras record all critical situations. The drivers’ reactions are of particular interest to the developers to further improve ATTENTION ASSIST.
Driver in the spotlight
To ensure comprehensive and representative data, a test in the driving simulator typically lasts several weeks and includes numerous test drives. The focus is on the people: the tests are geared towards finding out how they deal with a new technology or system in order to derive findings for new production vehicles.
The Mercedes-Benz simulator is the most powerful in the automotive industry worldwide. Sattled atop the moving hexapod is a real-life vehicle cockpit – for ATTENTION ASSIST it is an S-Class. The cockpit is enveloped by a 360° video dome, which shows a real-time simulation of a continually changing landscape throughout the journey. No matter where drivers look, they always have the impression that the journey is actually taking place; the landscape and houses flying by, cars overtaking or being overtaken, and of course the traffic behind seen through the exterior mirrors.
The landscape flies by
The hexapod sits on a twelve-metre rail powered by an electric drive motor, which allows the dome to move back and forth very rapidly. Through lateral acceleration the driving simulator can recreate authentic driving dynamics. Powerful computers control all components in real time. They react quickly and are characterized by a high degree of mobility,– steering, accelerating, braking, side winds, and emulating various road surfaces. All "vehicle stimuli," as the experts call them, can be felt by the test driver through the driver's seat as if the car was actually on the road.
Several months of preparation go into planning the study, but the effort is worth it. Surrounded by this deceptively real atmosphere the test drivers begin driving as soon as they are seated in the cockpit.The system provides the necessary framework for test exercise and tracks the results.
Daimler was an early pioneer with simulators. More than thirty years ago, in May 1985, the first driving simulator developed by Daimler was unveiled at the then Daimler-Benz Research Centre in Berlin-Marienfelde. Today, Mercedes-Benz engineers use the simulator in Sindelfingen in the production of all new vehicles – in many cases before it even drives on a road for the first time. "It reproduces highly dynamic driving manoeuvres realistically and allows us to research the behaviour of the driver and the vehicle in road traffic," says Bernzen. Of course the system cannot completely replace test drives completed at training sites and on public roads. These continue to be carried out in addition to simulator tests to gather real data.
How does a tired driver behave?
Today, during the ATTENTION ASSIST test in the driving simulator in Sindelfingen, none of the test drivers will reach their destination of Bremen. The sleepiest driver retires after only half an hour of driving. The most awake person perseveres for three and a half hours until fatigue finally sets in.
The tour in the simulator capsule ends after only half an hour for the sleepiest test driver
"What is most important for us as developers is that we were able to gather the data regarding the drivers’ critical limits, which we were after," Wiebke Müller explains who carried out the test together with a driving simulation team made up of human factor specialists and engineers. "Once the test series has been completed, we will analyse the comprehensive data sets and design the next generation of ATTENTION ASSIST." The first version of ATTENTION ASSIST was launched in 2009, the second followed in 2012. Having proven its efficacy in avoiding accidents, it has long since become standard equipment all of the brand's new cars. Today, more than 10 million vehicles equipped with ATTENTION ASSIST are on the road