Electronic driving assistance to prevent car accidents
A sudden obstacle on the road ahead. Should you slam on the brakes? Have you got enough distance? Will you also have to try to avoid the obstacle? Overtaking is another challenge to many drivers' judgement: is the oncoming traffic still far enough off or would it be better to ditch the attempt?
These were the questions addressed in two previous “PRORETA” projects. In cooperation with automotive supplier Continental, researchers were able to create ground-breaking technological approaches and demonstrate them in test vehicles with new sensors and computers. Many of their ideas have since found their way into mass production.
The project “PRORETA 3”, which was also conducted in close collaboration with Continental and concluded in 2014, combined a variety of approaches into an integral assistance system that features only two modes – safety corridor and cooperative automation. The safety corridor is a virtual area in which the driver operates his or her car under normal circumstances. If a hazard is detected, the driver will be redirected to a safe trajectory in a multi-stage process. If the driver wants to delegate navigation at least partially, he or she can activate the cooperative automation mode. Action on the driver’s part is required only when changing manoeuvres, yet the driver retains control over the vehicle at all times.
Safe, vigilant driving
The first project, PRORETA 1, from 2002 to 2006 investigated how to prevent accidents such as rear-end collisions. The system helps the driver decide whether to brake or avoid an obstacle. PRORETA 1 either brakes automatically, sends impulses to the steering wheel to prompt the driver to avoid an obstacle, or may even conduct the manoeuvre itself.
Between 2006 and 2009, the second test vehicle, PRORETA 2, showed that frontal collisions during overtaking manoeuvres on country roads can be avoided. It warns the driver about risky overtaking manoeuvres and aborts a dangerous attempt that is already underway if the driver ignores the warnings.
PRORETA 2 uses a video camera and radar to register what is happening ahead of the car and then pre-calculates the overtaking manoeuvre. For example, it calculates the “time to collision” and ensures that the driver always has sufficient time to change lane. In critical situations, the driver receives several warnings to abort the manoeuvre. If the driver fails to do so, the vehicle will automatically brake so that the driver can get back in lane behind the vehicle that was to be overtaken. These automatic interventions always take place at the last possible moment, when it is clear that the driver would react too late, if at all, to be able to prevent the imminent accident.
A blend of safety and assistance features
PRORETA 3, which ran from 2011 to 2014 and involved the TU Institute for Automation and Vehicle Technology and the Institute for Ergonomics (IAD), offers an innovative vision for an integral safety and assistance concept of the future. The virtual safety corridor is generated according to need and situation and guides the driver and vehicle back into a safe zone in the face of imminent danger. Cooperative automation allows for a high degree of automated driving under the driver’s control.
PRORETA 3 goes beyond individual traffic scenarios. It warns drivers about static and dynamic obstacles the car veers off the lane, it intervenes in emergencies and also prevents dangerous traffic violations, such as jumping a red light or driving down a one-way street in the wrong direction.
Once the driver activates the “cooperative automation” mode, he or she controls the vehicle by simply prompting certain manoeuvres such as a turn or lane change.
The following video shows the entire range of functionality of the PRORETA 3 system. Film source: Continental/TU Darmstadt