Portal monitoring with steered-beam RFID systems
AssigneeImpinj, Inc.
InventorsAlberto Pesavento, Adrian Wojnowski, Joshua F. Ensworth
Life of this patent
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Abstract
Portals and other chokepoints can be monitored with RFID reader systems. A portion of an RFID reader system capable of generating multiple beams can be mounted between two adjacent chokepoints such that some beams are associated with one chokepoint while other beams are associated with the other chokepoint. When replies from an item are received, the item can be associated with a chokepoint based on parameters or characteristics associated with the replies and/or the beam(s) on which the replies are received. If the detected item is moving, its movement direction through the chokepoint and/or its movement speed may also be determined.
Claims20
A method to identify a chokepoint through which a Radio Frequency Identification (RFID) tag is transitioning, the method comprising:
- generating, from a first reader, a first plurality of spatially separated reader beams oriented toward a first chokepoint and a second plurality of spatially separated reader beams oriented toward a second chokepoint different from the first chokepoint;
- transmitting inventorying commands on the first and second plurality of reader beams;
- receiving, from the RFID tag, a plurality of replies responding to at least some of the inventorying commands;
- determining, from the plurality of replies, at least one cumulative reply parameter;
- selecting, based on the at least one cumulative reply parameter, one of the first and second chokepoints as the chokepoint through which the RFID tag is transitioning;
- and
- determining, from the at least one cumulative reply parameter, a transition direction for the RFID tag through the selected chokepoint.
A method for a synthesized-beam reader (SBR) to track a passage of Radio Frequency Identification (RFID) tags through two neighboring chokepoints, the method comprising:
- synthesizing a first plurality of spatially separated beams oriented toward a first chokepoint;
- synthesizing a second plurality of spatially separated beams oriented toward a second chokepoint;
- transmitting inventorying commands on the first and second plurality of beams;
- receiving, from a first RFID tag and a second RFID tag, a plurality of replies responding to at least some of the inventorying commands;
- determining, from the plurality of replies, at least a first cumulative reply parameter for the first RFID tag and a second cumulative reply parameter for the second RFID tag;
- determining, based on at least the first and the second cumulative reply parameters, that the first and second RFID tags are simultaneously passing through the first and second chokepoints, respectively;
- and
- determining, based on at least the first and the second cumulative reply parameters, that the first RFID tag is passing through the first chokepoint in a first direction and the second RFID tag is passing through the second chokepoint in a second direction.
A method to track the passage of a Radio Frequency Identification (RFID) tag through one of two neighboring portals, the method comprising:
- generating, via both a first RFID reader and a second RFID reader, a first plurality of spatially separated beams oriented toward a first one of the portals;
- generating, via both the second RFID reader and a third RFID reader, a second plurality of spatially separated beams oriented toward a second one of the portals;
- transmitting inventorying commands on the first and second plurality of beams;
- receiving, from the RFID tag, a plurality of replies responding to at least some of the inventorying commands;
- determining, from the plurality of replies, at least one cumulative reply parameter;
- selecting, based on the at least one cumulative reply parameter, one of the first and second portals as the portal through which the RFID tag is passing;
- and
- determining, based on the at least one cumulative reply parameter, a passage direction for the RFID tag through the selected portal.
Dependencies are inferred from the claim text.