Occupant counting - IR cameras show promise

(2) Occupant Counting — IR camera promise

Military vision enhancement technology may provide a breakthrough for automated counting of vehicle occupants. The company that manufactures the night vision system for the Apache helicopter and for many US Army ground vehicles, Xybion Electronic Systems of San Diego CA has supplied a specialized infra-red camera to Georgia Tech Research Institute in Atlanta in experiments there on getting better pictures inside cars. Experiments continue also with regular video cameras to “see” into cars and count occupants, because of the difficulty and cost of doing this by human observation. The Texas Transp Institute is involved with one promising video project in Dallas TX. USDOT requires regular occupant count statistics from states with HOV lanes to see how HOV is working. Police want pictures for HOV and seat belt enforcement. The major problem with using visible light camera equipment is that the interior of a vehicle is so much darker than the exterior, and some vehicles have tinted glass. Also the sun shining on vehicles can reflect back ‘glint’ that blinds a regular camera

Gary Gimmestad of Georgia Tech Research Inst is working on a Georgia DOT project to test whether near visible range infrared will get over these problems. Visible light is 400 to 750 nanometers (nm) and beyond 1100nm windshield glass blocks IR, so Gimmestad wants to get in-between mostly 800 to 1000nm. In his setup a xenon strobe triggered by a SEO Autosense presence detector will produce a 1/100 second non-visible IR illumination of the interior of a passing vehicle which will then be photographed with the ultra highspeed IR camera from Xybion. It will produce a grayscale picture, which should clearly show the occupants, says Gimmestad.

With HOV violations a major problem is the difficulty, cost and disruption to other traffic of police have to spot, and then pull over and book violators. An automated occupant imaging system that could produce a time-stamped picture of the vehicle interior together with a license plate image could beef up enforcement of HOV enormously. It could be even more important for HOT projects. Georgia Tech is currently doing on-campus trials of the IR system and if these go according to expectations, there would be field trials in the autumn from an overpass on I-285, the beltway around Atlanta. (Contacts Gary Gimmestad Georgia Tech 404 894 3419; Rick Deaver Georgia DOT 404 363 7584; Richard Sturz Xybion 619 566 7850)