Modern RFID tags can both be read and written to, making them much more than a simple "license plate" to replace a bar code. RFID tags have typically been read over the air using RF energy from an interrogator, obtaining a 96-bit number that makes up its electronic product code. The latest RFID tags can contain 64 kbits or more of data and can be read by simply touching them with an appropriate probe.
Working together with Tego Inc. of Waltham, MA, the RFID Center of Excellence at the University of Pittsburgh has developed what the team has coined “touchprobe" technology for related avionics applications.
“Using this technology we can embed RFID chips into anything,” said Dr. Marlin H. Mickle, Nickolas A. DeCecco Professor, University of Pittsburgh. “We are able to write and convey information to them with a proprietary signature that can be used at any point during the lifetime of the part.”
Passive RFID provides commercially available readers, antennas, and tags including chips mounted on the tags. The reader transmits RF energy over the air, communicating with the RFID tag, which contains memory and information.
In contrast, the touchprobe simply connects to the reader with two contacts that touch the RFID chip directly, bypassing the antenna and all the problems associated with over-the-air interference as well as issues with the surface on which the tag is mounted.
Touchprobe technology allows the embedding of chips into very small parts, while large parts can be equipped with more sophisticated RFID implementations. By touching the part with a probe that is linked to a computer, the reading actually goes out over the Internet and talks with "home" for in situ diagnostics.
“Boeing is currently a member of our center,” said Mickle. “Tego has also been talking with Airbus for a range of commercial applications such as tags that can be embedded in all key components of a commercial airliner.”
RFID chips can be embedded into the smallest of these parts and devices, providing efficient “cradle-to-grave” tracking of maintenance.
In addition to basic parameters, each device on an aircraft requires lifetime documentation. RFID eliminates a massive data file accumulation and creates one internal traveler that can be continually updated electronically.
“We primarily work on the technology that allows people to do what they can’t do with standard, off-the-shelf RFID technology such as used for simple cargo tracking,” said Mickle. “Number one is finding and using the energy to power the RFID tags more efficiently. Number two is the ability to use RFID tags in circumstances that people may not have considered.”
As commercial aircraft become ever more complex, identification is required on each item as it is received as part of the assembly process. RFID streamlines the actual assembly process of each aircraft and ensures the lifetime tracking of every part that goes into the “build” of the craft.
While this return on RFID investment is obvious to the aircraft engineer and ensures a well-built craft for the passenger, it is not one that the everyday commuter can always appreciate. However, there is one area every passenger can relate to.
As a plane sits on the tarmac, an inventory must be done on all the various devices that are on board for passenger safety before the plane can take off. Each product has a date by which it must be checked or serviced on the ground to ensure safety once the plane is in the air. This has traditionally been done manually by reading bar codes with a hand reader, going from front to back on the aircraft. However, bar codes only hold limited information. They also expire and need to be replaced.
Using RFID tags, the reader is passed through the plane, automatically gathering data. Considerable time savings can be achieved over visual inspection methods and bar codes, enabling passengers to board quicker.
When considering all the components that must be serviced, Mickle says that it is important to think of the paperwork involved with each item, be it safety equipment or an airframe that must be regularly serviced. One of the highest impact areas for RFID is where there is a clear savings in person-hours and eliminating mistakes involved with lost documentation.
“Components may have a certain date where they must be pulled and replaced or re-certified. With RFID, you can feed in when this was done and exactly who did the replacement and/or maintenance on them,” said Mickle. “This extends from things inside the passenger compartments to doors, insulation, landing gears—virtually anything. Tego tags provide complete data and maintenance history that may be linked to the Internet. RFID provides a running real-time log of everything on the plane without excessive time and labor.”
Using RFID, and particularly with the ease of touchprobe data access for very small or hidden items, everything is always up to date. Information can be changed and updated easily.
“With bar codes, you couldn’t do this at all, but with RFID you can,” said Mickle.