Distance Control (acoustic)

Function

Some drivers who bought modern, aerodynamic cars with big trunks, but as well owners of Coupes, convertibles and vans experience that their vehicle is badly observable to the rear. An acoustic electronic distance control can moderate the problem. This system alerts the driver while driving backwards with tone intervals indicating the distance to obstacles thereby protecting human beings and the car against damages.

How it works

Three, four, or even five converters send out ultrasonic waves and record how long it takes for them to be reflected. The recorded time is put through to the control unit which switches on whenever the reverse gear is in use. The control unit starts off the whole system and the driver should hear a short tone when putting the reverse gear. If there is no sound this indicates an error in the system. The closer the car approaches any obstacle in the range from 160 to 20 cm, the shorter the intervals between the sounds become. A steady tone is a warning of close contact. Comparing the recorded times of the single converters, the software of the control unit can exactly determine the distance to obstacles even if the obstacle is situated in between two converters. Also wide obstacles are recognized. In case of wide obstacles the steady tone might cease if the distance does not change for some time. The system works to a large extent independently from other systems and can therefore be relatively easily added after the car was bought. It is not necessary to put a wire from the rear through the whole car to the transmission; it suffices to make a connection with the backup light. There are similar systems for the front side of vehicles. In several research departments they are experimenting with possibilities of electronically coupling vehicles with this or similar technologies, for example trucks.