By Beth Bacheldor
Some day, your car’s dashboard may alert you that there’s a pedestrian, bicyclist or person in a wheelchair in your path. That’s the dream of three researchers—Soichi Kubota, Yoshiharu Okamoto and Hideo Oda—who developed a prototype RFID system that could help prevent accidents by giving drivers advance notice that people are on or near the road. They recently tested the system, working with the Yokosuka Intelligent Transport Systems (ITS) Research Center, which develops technology to help reduce traffic accidents.
The researchers applied for and received a radio license from the Japanese government in December 2006, and in early 2007 conducted a field test of the RFID system at an intersection near the ITS Research Center in Yokosuka, Kanagawa. For the trial, two cars were fitted with an on-board vehicle communications and navigation system; it includes an RFID interrogator, special software and a display monitor on the dashboard. A UHF RFID active tag, operating in the 950 MHz frequency range, was affixed to a bicycle. The researchers also installed a low-frequency signal generator in the street and three RFID repeaters on the side of the road.
Here’s how the system works: When a tagged bicycle enters the intersection, the generator emits LF electromagnetic induction waves that communicate its position to the tag; that, in turn, excites the tag to emit its own RF signals, which have a unique ID number and the generator’s positional data. When a car nears the intersection, the repeaters pick up the tag’s RF signal and communicate the data to the interrogator on the car. The car’s communications system processes the tag data and cross-references it with the car’s position and direction of motion (determined by the navigation system). If it determines the tag is in front of the car, an alert appears on the display monitor on the dashboard.
The field test validated the system but Kubota says it’s not ready to be developed into a commercial product, because it’s impractical to reconstruct intersections so that the generators could be buried in the roads. Without those exciters, the tags would have to communicate directly with the vehicles, which would require a more expensive GPS device. Nonetheless, the researchers plan to continue working on the system, adding safety features that will warn tag carriers of approaching vehicles. “We will improve the hardware and software,” says Kubota, “and do more field tests for verification and efficacy of the system until December.”