Driver assistance – but safe!

Advanced driver assistance systems can make the traffic safer. In particular active security systems can prevent accidents. The Virtual Institute DESCAS is conducting research on how to create these systems more reliable and how to form a safety network if the system fails. In DESCAS - the abbreviation of Design of Safety Critical Systems- the German Aerospace Center. (DLR), the University of Oldenburg and the Technical University of Braunschweig are going to be collaborating from March on.

Brake assist systems, lane departure warning systems, ACC (Adaptive Cruise Control) and ESC (Electronic Stability Control) take corrective action if the driver is inattentive or his abilities are not enough. ESC, for instance, can stop all four wheels to a different extent in order to avoid a pulling of the vehicle. The automatic emergency brake prevents driving too close to the vehicle in front and thus the accident. But what happens if the system does not intervene? For instance if a laser that should have recognized the vehicle in front fails, or if distance and speed are not interpreted correctly?

To answer this and further questions concerning new safety critical assistance systems, DESCAS is developing a safety-driven process of development. First of all, the kind of safety system must be defined, to identify weaknesses accordingly, and to pre-estimate their consequences. In case of failures and malfunctions, which can never be ruled out totally, it is required to minimize them – similar to requests in aviation. On this basis, the possibilities to counteract mistakes have to be considered in the development. For example a second pair of security-relevant sensors could be installed. Or the software falls back on the radar instead of the laser, to identify a gap, for example.

Strategies are also developed for the case an active safety system does fail despite redundancy and alternative procedures. In road traffic the driver relies on his electronic assistance. “If this fails the driver has to be informed, and he has to know how to handle the situation”, Jürgen Rataj of the German Aerospace Center explains. By now he is responsible for concepts and technology for driver assistance in the DLR-Institute of Transportation Systems, and spokesman of DESCAS. Thus the scientists also take into considerations the drivability, which is identified by means of driving simulators and a test track.

DESCAS is one of ten Virtual Institutes which have been granted by the Helmholtz Association lately. Virtual Institutes combine competences of universities and Helmholtz centres, variable in location, subject and organization. They rely on the qualification of their junior scientists. DESCAS is uniting the competence of three different partners: The DLR-Institute of Transportation Systems concentrates on a human-centred creation of driver assistance. The research centre “safety critical systems” of the University of Oldenburg has experience in the field of software development and formal verification. The Institut für Verkehrsführung und Fahrzeugsteuerung of the University of Braunschweig comes up with a holistic approach to researching methods, descriptions and formal valuations.