May 14, 2008This article was originally published by RFID Update.
May 14, 2008—The US Army is investigating the use of sensors integrated with RFID tags to keep maintenance of heavy gun barrels on target. The Army is testing an RFID-based sensor system to record and store how often the cannons on M1 Abrams tanks are fired. The data will support proactive maintenance operations and help the Army determine when the barrels near their end-of-life and should be replaced.
The testing is being coordinated by Benét Laboratories, an Army research and development facility in upstate New York. RFID and sensor system development firm Augusta Systems of Morgantown, West Virginia, is working with Benét Laboratories and provided technology for the project.
It is important to track how often tank cannons and other artillery pieces are fired because the barrels can withstand only so much shock and recoil before they must be refurbished or retired. Deducing shots fired based on ammunition consumed has not been effective, and processes that would require soldiers to keep records while in combat are far from ideal. Working under these limitations, weapons usage has traditionally been estimated, which can lead to assets being retired at the wrong time.
In response, last fall the Army began testing a sensor-based system that records readings on an integrated RFID tag. Each time an M1 Abrams tank fired its cannon, a tank-mounted sensor captured the recoil and recorded the event on an integrated passive RFID tag. The data was retrieved with a handheld reader when the tank returned to the depot. No manual data entry or record keeping was required, and the system proved accurate after tracking hundreds of shots.
"This has been a wonderful combination of the use of sensors and RFID technology," Augusta Systems president Patrick Esposito told RFID Update. "However, finding tags that fit the project requirements wasn't necessarily easy."
Esposito said one of the concerns was that the powerful recoil would cause the RFID tag antenna to separate from the chip. "RFID tags aren't built specifically for this kind of use environment," he said.
For the live field tests, project planners selected battery-assisted UHF tags from Intelleflex, which Augusta Systems combined with sensors into a single item in a ruggedized housing. The model STT-7700 tags have 60 kilobits of user memory, which is sufficient to store firing data for 500 rounds. Esposito said the tags performed very well after Augusta Systems and Benét Laboratories experimented with different placement locations on the barrel and protective housings for the tag.
"From initial testing results we learned that proper performance depends on a balance of tag placement and tag housing, with housing worth about 80 percent," Esposito said.
Esposito said he was very pleased with the tag and sensor performance, but noted other brands of tags will be evaluated in the next round of testing, which is scheduled to begin in September. The sensor system could find its way into use as early as next year, according to Esposito.
"The initial focus was to test the prototype and to just count the number of rounds fired," said Esposito. "The next stage will focus on more advanced characteristics, such as intensity measurements for each round fired. The more ruggedized system will be tested this September, then we'll be in the final stages of making the technology available to anyone in the military that wants to deploy it in the field."
Esposito said the system has a clear opportunity to improve maintenance, repair and overhaul (MRO) of weapons, but could also have a broader impact on how maintenance systems are viewed.
"We've put the technologies into play that allow us to bring together data from disparate sources, be they sensors, video, RFID, or other edge device data," he said. "We do believe there are many other opportunities out there to deploy converged sensor systems to improve enterprise data and its availability."
The weapons sensors systems are independent of RFID technology and products covered by the Army's recently issued request for proposals (see US Army Issues RFP for Large RFID Purchase and Army RFID Contracts to Create Market Boost, Not Boom).
The development of RFID tags with higher memory capacities and other features is helping RFID gain traction for MRO applications. Intelleflex was previously selected by Boeing to provide tags for an aircraft maintenance application, in part because it offered some of the highest-memory tags available at the time. Fujitsu and NXP Semiconductors each cited maintenance applications when they announced expanded memory passive UHF tags last year (see Fujitsu Announces Roomy 64KB Gen2 RFID Tag and NXP Doubles Memory on Gen2 RFID Chips, respectively).
