This article was originally published by RFID Update.
April 23, 2007—RFID is routinely used to collect highway tolls. Now an Australian firm is planning to use the technology to prevent highways from taking their toll on drivers. Telepathx has developed a system that integrates RFID tags, crash sensors, and wireless mesh networks to automatically detect crashes, assess the severity, and report the incident to public safety forces.
Telepathx, which operates remote monitoring systems for bush fires and other applications, and already has an extensive wireless mesh network infrastructure throughout Australia, hopes to trial its crash detection system in the Australian state of Victoria, managing director James Eades told RFID Update.
“Bringing intelligence to energy networks and detecting bush and wild fires is our core business. Monitoring auto accidents was a natural fit because the system will already be there,” Eades said in an e-mail. “Our network of remote transmission units (RTUs) is located on utility poles, about every 250 meters, and they have the ability to monitor just about anything within range.”
Key to the crash detection system is an RFID tag with integrated impact sensor. Telepathx envisions attaching the tags to guardrails, utility polls, and other roadside structures. When the sensor detects an impact, the RFID tag communicates to RTUs in the area, which then dispatch the information.
The 433 MHz RFID tags can communicate with RTUs from at least 125 to 250 meters away. The system assesses the severity of the impact based on how many RTUs are signaled. A high-impact collision would trigger sensors throughout the guardrail, which would signal more RTUs and indicate that the incident was serious. Wide area communication can be done through Telepathx’s legacy wireless mesh network plus GSM, CDMA, and more advanced wireless technologies, and a satellite communication is in development. GPS can also be integrated to provide precise location data.
“Other systems are out there, but they are way too sensitive and create a lot of false positive readings — not good,” said Eades. “No one is interested in monitoring paint scrapes.”
The sensor tags measure approximately a cubic inch and cost $20 to $25 Australian (US$17 to $21), according to Eades. He said 433 MHz technology performs best in this application, and has the added advantage of costing less than alternative frequencies.
“We get a lot of comments about frequency choice and why we don’t move the whole platform over to 2.4 GHz or higher,” he said. “Most of our sensors will be going off in some pretty extreme conditions — fog, rain, snow, hail, and in ash clouds — and we have greater confidence that 433 MHz works much better than 2.4 or 5.8 GHz at 125 meters in these conditions. We are only sending 20 to 30 bits of data, so it’s hard to justify the added cost of going to higher speeds for the sake of a few milliseconds.”
The system has not been installed anywhere yet, but Telepathx hopes to trial it on its Victoria network.
Because it is sensor-based, the Telepathx system is fundamentally different from reader-based systems that have been developed to read tags from passing vehicles or cargo containers for supply chain visibility applications, or from the interactive marketing system to display customized electronic billboard messages (see RFID Enables Personalized Billboard Displays).
The International Technology Alliance in Network and Information Sciences (ITA), a $135.8 million, 10-year research partnership formed last year (see Transatlantic Consortium to Research RFID) may conduct research into tag and sensor technologies and applications similar to those developed by Telepathx. Sensor-based RFID systems are the subject of extensive research and commercial development, but most focus on item-level traceability for security, inventory, and cold chain management.