Active safety functions: driver assist systems of the future

Experts understand “active safety” to mean all elements and functions of a vehicle that can help to avoid an accident^*. “Aside from suspension, tires, brake system and lighting technology, these also include assist functions^* that advise of potential hazards early on, issue a warning in the event of acute danger and, if the driver does not react in time, also automatically apply the emergency brakes or take evasive action,” explains Roland Kallweit, Head of Development Active Safety Functions at AUDI AG. His team of 20 employees looks after three main areas: The first involves “warning, braking and swerving” the vehicle. The second focuses on proactive occupant protection functions and the third on the Car2X^* systems. All three areas have the same objective: “We want to use these functions to improve safety on the road for all road users – both for our Audi customers and vehicle occupants as well as for all other road users such as cyclists and motorcyclists.”

The Audi developers faced many challenges in the course of developing these technologies: “The vehicle’s maneuvers are subject to legally anchored requirements. Whereas swerve assist provides support if the driver leaves their lane, Automatic Emergency Steering means that the Audi practically maneuvers independently in its own lane, unless and until the driver intervenes^*. With both systems, however, the driver always remains in control of the vehicle, since even not intervening constitutes a decision. The driver can therefore override the assist system at any time,” explains Christoph Liebelt. A further challenge the development team faced in bringing the technologies to market maturity was to reach agreement on the intensity of the automatic steering intervention. This required a great deal of sensitivity. “It was important to us that driver and passengers feel safe and never feel that they are not in control. Nonetheless, our steering interventions need to be an effective call to action, since ultimately we are aiming to avoid an accident.”

“We use functions like electrical tightening of the seat belts to minimize forward or sideways displacement of the car’s occupants, closing windows to the greatest extent possible and issuing visual warnings to other road users so that we can proactively increase the safety of the vehicle occupants,” says Thomas Bleier. “To do this, an Audi uses data from sensors installed at the front, side and rear of the vehicle to calculate the probability of an accident^*.”

The system initiates a number of proactive protective measures if it detects a risk of collision or in critical driving situations – such as emergency or hazard braking or when handling at the limits – even before a collision or impact occurs^*. Proactive occupant protection is activated if there is a high probability of impact. Thomas Bleier: “We carry out a “reality check” in Northern Europe each winter with pre-series vehicles, for example, to test how the systems react and what the potential impact would be on the vehicle occupants.” This is done on closed-off test tracks on frozen lakes and with obstacles. “We simulate the seconds before an accident in numerous scenarios, maneuver the vehicles constantly at the limit and optimize the systems – so that they later provide the best possible protection for all road users.” 

The Audi developer differentiates in this context between two forms of communication: direct communication and backend communication^*. In the case of the latter, hazard alerts are sent in good time from a server to other road users and hazards detected by the vehicle are made available additionally to the service provider. With direct communication, the vehicles in close proximity can communicate directly with each other, for example via Wi-Fi or the cell phone network. “A lot will happen in the area of Car2X in the future, especially in terms of direct communication between vehicles. Customers will be provided with more and precise hazard alerts from their immediate vicinity. We are convinced that this will allow traffic safety to be improved further,” says Mamoon Nomaan. “Ever since 2019, our experience with this technology on the Chinese market has been positive. The transmission standards have already been defined in North America, while they are still being discussed in Europe at present. But one thing is certain: the greater the swarm of vehicles and the more data we process on current traffic conditions, the simpler it will be to issue warnings about specific hazards and to improve road safety overall.”

Issuing a light warning to cyclists may seem simplistic, but its relevance can be seen by casting a glance at the accident statistics^*: in Berlin alone, almost two accidents^* on average are reported to the police every day, involving cyclists crashing as a result of car doors being opened and in many cases sustaining serious injuries. “Through our technologies, we support the Vision Zero road safety strategy in many countries around the world, which is based on the belief that no death or serious injury is acceptable on roads,” says Roland Kallweit.