RFID MARKING OF UNITS IN A SPACE

• US 20130314212A1
• Filed: 05/22/2012
• Published: 11/28/2013
• Est. Priority Date: 05/22/2012
• Status: Active Grant

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Zogg, Edward, Rimai, Donald Saul, Hinman, Mark P.
• Granted Patent: US 8,766,777 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• CPC Class Codes: G01S 1/02 using radio waves G01S19/00 takes precedence
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: G06K 7/01 Details
• CPC Class Codes: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: H01Q 3/245 in the focal plane of a focussing device
• CPC Class Codes: H01Q 3/30 varying the relative phase between the radiating elements of an array H01Q3/2605, H01Q3/2658, H01Q3/2682, H01Q3/44 take precedence
• CPC Class Codes: H04Q 2213/13095 PIN / Access code, authentication

Abstract

Non-RFID-active units in a space are marked by affixing RFID tags. Two tags are affixed to each unit, each tag having a directional antenna. The antennas are oriented to define a per-unit reader location. Units are arranged in the space so the per-unit reader locations at least partially overlap to define a reader location. The units in the space can also be detected by an RFID reader located in the overlapping per-unit reader locations. A controller can compare a received list of tag identities corresponding to units expected to be in the container to the identities of the tags read to determine whether the expected units are in the container and disposed at positions and with orientations that cause the respective per-unit reader locations to at least partially overlap with the reader location.

Claims

1. A method of marking a plurality of non-RFID-active units in a space, the method comprising:

providing the plurality of non-RFID-active units;

affixing two RFID tags to each unit at respective, different tag locations on the unit, each tag including a respective directional antenna steered in a respective, different antenna direction, so that respective directional propagation patterns are defined; and

disposing each unit within the space at a respective unit position;

so that the propagation patterns of the tags for each unit intersect to define a respective per-unit reader location with respect to the respective unit position, and the tag locations, antenna directions, and unit positions are selected so that the respective per-unit reader locations for each unit disposed in the space at least partially overlap to define a reader location.

2. The method according to claim 1, wherein the space is the interior volume of a container, and the space is large enough to completely enclose at least one unit.

3. The method according to claim 1, wherein the space is a selected area of the deck of a ship.

4. The method according to claim 3, wherein each unit is an intermodal container at least eight feet long.

5. The method according to claim 1, wherein each RFID tag is adapted to transmit a data value, the method further including affixing a respective mesh-network node to at least one of the units before disposing the units in the space, so that when a unit bearing one of the mesh-network node(s) is disposed in the space, that mesh-network node joins a mesh-network with any other nodes in the space, detects the respective data value(s) of at least one of the RFID tags, and transmits the detected data value(s) through the mesh-network to a reader outside the space.

6. The method according to claim 5, wherein the units are RF-blocking, and the mesh-network-affixing step includes affixing at least two respective mesh-network nodes to at least one of the units, the mesh-network nodes being disposed on different sides of the at least one of the units, and electrically connecting the affixed nodes for each unit to permit the nodes to communicate.

7. The method according to claim 1, wherein the RFID tags are passive tags.

8. The method according to claim 1, further including, after the affixing and disposing steps, activating an RFID reader having an antenna at the reader location to verify that both tags of each unit can be read.

9. The method according to claim 1, further including locating a respective site for each unit before disposing that unit, so that the respective unit location is located at the respective site.

10. The method according to claim 9, wherein the space includes a plurality of RFID tags having respective, different identifiers, and the locating step includes reading the identifiers of at least some of the tags to find a tag with an identifier corresponding to the unit to be disposed and locating the respective site adjacent to or including the location of the corresponding tag.

11. A method of detecting a plurality of units in a space, the method comprising:

receiving the plurality of non-RFID-active units disposed in the space, each unit at a respective unit position, each unit having affixed thereto two RFID tags at respective, different tag locations on the unit, each tag having a respective identity and including a respective directional antenna steered in a respective, different antenna direction, so that respective directional propagation patterns are defined;

wherein the propagation patterns of the tags for each unit intersect to define a respective per-unit reader location with respect to the respective unit position;

activating an RFID reader having an antenna located at a reader location to read the respective identity of one or more of the RFID tags;

using a controller, automatically receiving a list of tag identities corresponding to units expected to be in the space and comparing the identities of the tags read to the received list to determine whether the expected units are in the space and disposed at positions and with orientations that cause the respective per-unit reader locations to at least partially overlap with the reader location.

12. The method according to claim 11, further including reporting an error if the respective identities read do not match the received list.

13. The method according to claim 11, wherein the RFID tags are passive tags.

14. The method according to claim 11, wherein the space is the interior volume of a container, and the space is large enough to completely enclose at least one unit.