Alien Technology announced today that its Intelligent Tag Radar, which enables users to determine the direction, distance and speed of an EPC Gen 2 UHF passive tag, will be available beginning June 30. The software also allows an Alien interrogator to singulate a tag in close proximity to other tags. Alien Technology previewed this software at the RFID Journal LIVE! 2008 conference in April of this year.
“People are moving out of pilot projects [using RFID] and toward real installations,” says Scot Stelter, Alien Technology’s director of reader product marketing. “One thing Alien wants to do to help that process is to make RFID more effective, by providing actionable information that goes beyond the tag ID number.”
The software works by analyzing the data it collects during each read event—that is, every time a tag is detected within the reader’s interrogation zone. To singulate each tag—in other words, to identify one tag within a group of tags in close proximity to one another—Alien’s ITR software locates the “top dead center,” or highest point of the frequency wavelength, of each tag’s signal in relation to the antenna, in order to determine when the tag is directly in front of that antenna. This technique is similar to how radar systems locate airplanes, Stelter explains.
The level of accuracy of the singulation function directly correlates with the number of tags within a reader’s interrogation zone, as well as the tags’ distance from the reader antenna. According to Stelter, it will work best for singulating tagged items moving down a conveyor belt, wherein the reader antenna is mounted next to the passing items. In this scenario, he says, tagged items spaced just a couple of centimeters apart can be singulated. Having more items farther from the reader makes singulation more challenging.
Additionally, the software can determine a tag’s velocity, or speed in motion, enabling a user to discriminate between stationary and moving tagged objects. To measure velocity, the user must attach two antennas to the reader running the ITR software. A tag is singulated by each antenna as it passes by, indicating that tag’s direction (i.e., whether the tag is moving right to left, or left to right), and as well as its speed.
According to Stelter, this feature can be employed to automate decision-making based on tag speed and location, which could prove useful in some asset-tracking applications. The ITR software can determine the speed of a single tag within a reader’s interrogation zone at up to 50 miles per hour. It can track the speeds of multiple tags in its interrogation zone, though the software can measure velocity only up to 30 times per second. Tracking the speed and direction of 30 tags within an interrogation zone, therefore, provides that data once per second.
To determine a tag’s distance from a reader, the ITR software uses an algorithm that counts the wavelengths of a tag’s response to interrogation. The distance of any tag within a reader’s interrogation zone can be determined, Stelter says, with an error margin of 10 percent. (If a tag is 10 feet from the reader, for example, the software may come up with a calculated distance of 9 or 11 feet, instead).
The ITR distance function is slated for use in an unlikely military application, though it was not developed specifically for this purpose, Stelter says. “When a military helicopter hovers over a load that it will transport, it uses a laser range finder to measure the distance between the cargo and the helicopter,” he says. “But in desert or arctic environments, the rotors on the helicopter blow up enough sand or snow to interfere with those laser readings.”
As an alternative, Stelter says, the military has tested utilizing the ITR software on a reader mounted within the helicopter, used to read a tag attached to the cargo in order to determine its distance from the aircraft. With this information, he explains, the pilot can quickly maneuver the helicopter in such a position the person standing atop the cargo can grab the cargo hook extended from the helicopter to that cargo.
Outside the military, Stelter says, there are a number of other beta testers who have evaluated ITR as well, including RFID systems integrator Xterprise. “The functionality [that ITR provides] is pretty exciting, because knowing the direction and velocity of a tagged object allows you to add context to reads,” says Dan Ahearn, Xterprise’s VP of alliances and partnerships. “The more granularity I can get on each tag read, the better.”
Stelter also notes that the ability to singulate tags makes ITR attractive to airlines and airports employing RFID to track luggage, because it can reduce the number of physical barriers they must install on baggage-handling equipment to ensure that only the luggage directly in front of a particular reader antenna is detected.
Alien is not the first vendor to introduce a platform designed for adding additional context to EPC Gen 2 tag reads. Three startups—Los Angeles-based Mojix, RF Controls, in St. Louis, and Silicon Valley’s Wirama—have introduced products in recent months that provide not only a tag’s distance from a reader, but also its location in three dimensions (see New RFID Technology Helps Kraft, P&G, Kimberly-Clark Go the Distance and RFID 2.0). All three companies’ systems use advanced phased array antennas to determine location. Mojix, Wirama and RF Controls have not yet released pricing, though their systems are likely to cost significantly more than conventional UHF readers.
Alien is offering its ITR software for free. Beginning June 30, existing users of the company’s ALR-9900, ALR-9800 and ALR-8800 readers can download the software as a firmware update from the Alien Web site, along with a software developers kit and application notes. This will be available to those who purchase new ALR-9900, ALR-9800 and ALR-8800 readers as part of the Alien Reader Protocol software, which comes preloaded on the interrogator and also includes tag data filters and reader configuration settings.