Ranger: Measurement of Vehicle Interdistance

Maintaining the safety distance, together with respecting the speed limits, significantly reduces the risk of road accidents and improves the traffic flow in case of overloaded road networks.

In order to detect violations of vehicle interdistance limits, Aitek has developed the AiVu-Ranger system, based on its solid expertise acquired in the video technology and computer vision sectors.

AiVu-Ranger is based on the processing of video signals generated by video cameras covering a road section of length equal to the minimum allowed interdistance. Digitalization and video signal processing techniques allow to detect vehicles inside the road section, which is classified as clear or occupied after each data processing.

A sensor detects the entrance of a vehicle in the monitored section S and triggers the safety distance detection: if the monitored section is clear, the vehicle about to cross such section is respecting the safety distance limit.

If instead the monitored section is occupied by at least one other vehicle, the vehicle about to cross the section has committed an infraction, since the distance between the vehicles is less than the length of the section.

Violations are detected by applying video signal processing techniques to the signals acquired by a set of video cameras: in order to measure the vehicle interdistance, the monitored section S is divided into segments, each of which is monitored by a video camera. The system detects vehicles in each of the segments monitored by video cameras: a vehicle about to cross section S does not commit an infraction if all segments are clear.

In order to measure the distance between vehicles, the system employs advanced video processing techniques 

monitored by a video camera in a given number of adjacent cells of equal length. The video signal processing algorithm of each video camera is able not only to define the state (clear / occupied) of its associated segment, but also to provide information on the particular cell which caused the segment state and to measure the interdistance.

In case of safety distance violations, the images containing the licence plates of the infringing vehicles are stored by the system, which will warn control room operators of the violation.

AiVu-Ranger is currently being tested inside the Monte Bianco Tunnel, and Aitek has filed an international patent application (ref. WO2008/059538A1).