Automotive supplier Continental AG has announced to add a stereo camera to its ContiGuard safety system as an integral element of its forward looking braking systems. This will help prevent or at least reduce the seriousness of the frequent accidents involving pedestrians or with vehicles at intersections. The stereo camera realizes the already familiar assistance systems, such as Lane Departure Warning, Traffic Sign Recognition, and Intelligent Headlamp Control.

Stereo Vision Camera for Driver Assistance SystemSince the stereo camera has two ‘eyes’, it is able to use the difference in the images within one camera shot to detect every type of obstacle, from loads that have fallen onto the road to people and animals, and can determine their size and the distance to them. This cannot be done sufficiently reliably with mono-cameras, which also have to be taught to recognize a car or a motorcycle and which are then only able to identify objects that they have learned.

The stereo camera consists of two high-resolution CMOS mono-cameras, housed approximately 20 centimeters apart behind the windshield. Whereas a mono-camera only estimates distances, the stereo camera measures the distance to an object and its height from the road surface. This is made possible by the differences in the perspective between the left-hand and the right-hand optical paths. In other words, the stereo camera’s analyzing electronics exploit the same effect that gives humans spatial vision, i.e. the parallax shift between two images.

Since the stereo camera can also identify potential ways, within its field of vision, in which the vehicle could take evasive action, other options are for a collision warning to be issued or for automatic braking to be applied earlier if no evasive maneuver is possible. The advantage of this is that a few hundred milliseconds are sufficient for an emergency stop to make the difference between sustaining bruises and suffering far more severe injuries. With its range of up to 60 meters, the stereo camera provides the best possible basis for developing braking systems that are truly looking-ahead.