Successfully Reading RFID Tags

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Background: The 100% (or near-100%) read-accuracy target is not met with current systems and because of this, fails to gain industry wide adoption of RFID technology, especially in item level applications. The read range fails to capture the true read-accuracy when orientation of tags on products or cartons cannot be fully controlled during the scanning process. Exact locations and orientations of scanned items in a supply chain system are not always fixed in a typical interrogation process. In mixed-tote applications, groups of items may appear at different heights and locations. When items are scanned as they pass by on a conveyor belt, the relative orientations keep changing during the interrogation process. Current methods for analyzing how to deploy multiple RFID reader antennas in order to maximize the likelihood of reading RFID tags do not explicitly consider the orientation of the tags. This results in suboptimal antenna locations that reduce the RFID system effectiveness.    Technology: Researchers have developed methodologies that provide fundamental theoretical support to analyze how to optimize multiple antenna placements in order to improve read-accuracy in RFID technology applications in supply chain systems.The technology disclosed is software with embedded algorithms to optimize multiple antenna placements on RFID readers in order to improve the read accuracy of RFID tags. Through taking a scientific approach we have used an approximation algorithm of distributing X points uniformly on a sphere and generated a preferred tag orientation. The results show that using two antennas working as a pair is the optimal solution. The pair of antennas complement each other with respect to the tag orientation and greatly enhance the read accuracy. The software uses modeling of the power requirements of the backward link and forward link of the RFID tag interrogation process. Using this methodology, it considers the power received by an RFID tag to not only be related to the distance along the path that the signal traverses, but also to other factors such as the orientation and polarization of the antennas of both the RFID readers and the tags. This discovery is applicable to situations where the tags can take any orientation with equal probability, as well as situations where the orientations are limited to certain specific orientation. This proves to be a computationally challenging problem since the tag area and the reader positions are in three dimensions with an infinite number of locations. The software develops discretization schemes and analyzes parameters to reduce the computational complexity without compromising the precision of solutions.    Application: * Supply chain systems   Advantages: * Improves tag reading accuracy and provides possible cost savings. * Implements the first rigorous model applied to the backward link and moving analysis problems of RFID tags. * Considers the power received by an RFID tag to not only be related to the distance along the path that the signal traverses, but also to other factors such as orientation and polarization of the antennas of both the RFID readers and tags. * This methodology considers the fact that exact locations and orientations of scanned items in a supply chain system might not always be fixed in a typical interrogation process.