RFID material tracking method and apparatus

• US 8,378,789 B2
• Filed: 08/31/2007
• Issued: 02/19/2013
• Est. Priority Date: 08/09/1999
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: Round Rock Research LLC
• Inventors: Moore, Scott E.
• Primary Examiner(s): Nguyen, Nam V
• Application Number:
  US11/897,591
• Publication Number:
  US 20070296595A1
• Time in Patent Office: 1,999 Days
• Field of Search: 340/10.3, 340/825.49, 340 101- 105, 340/825, 340/36, 379/106.11, 455/88, 455/95, 341/33
• US Class Current: 340/10.3
• CPC Class Codes: G06K 17/00 Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: G08B 13/2462 Asset location systems combined with EAS inventory, tracking, logistic G06Q10/00; entrance control systems G07C9/00

Abstract

A method and apparatus for tracking items automatically is described. A passive RFID (Radio Frequency IDentification) tag is used with a material tracking system capable of real-time pinpoint location and identification of thousands of items in production and storage areas. Passive RFID tags are attached to the item to be tracked, remote sensing antennas are placed at each remote location to be monitored, interrogators with several antenna inputs are connected to the sensing antennas to multiplex the antenna signals, and a host computer communicates with the interrogators to determine item locations to an exacting measure.

Claims

1. A method for managing inventory, comprising:

attaching a radio frequency identification (RFID) tag to each of a plurality of objects;

associating a database entry with the objects and each corresponding RFID tag in a central database;

positioning a plurality of interrogators at a plurality of locations, each of the interrogators being configured to perform wireless communications with corresponding RFID tags via a sensing antenna, wherein each sensing antenna is provided with a location identifier;

the interrogators exciting the corresponding sensing antennas to receive identifying information from at least some of the corresponding RFID tags;

determining the RFID tags from which identifying information is not received at the interrogators;

in the event that the identifying information is not received from at least one of the RFID tags, determining whether a current iteration count for determining if identifying information is received at the interrogators is above a limit for the number of iterations;

in the event that the current iteration count for determining if the identifying information is received at the interrogators is not above the limit for the number of iterations, incrementing the iteration count and disabling and then enabling a driver for each sensing antenna;

in response to enabling the drivers for the sensing antennas, receiving by the respective interrogators the identifying information from each RFID tag that is within communication range of the excited sensing antennas;

determining a storage location of each object based on the identifying information of the corresponding RFID tag and the location identifier of the sensing antenna that is positioned closest to the object relative to the other sensing antennas;

updating by the respective interrogators the database entry associated with each corresponding RFID tag to indicate the storage location of the objects; and

retrieving inventory management information from the central database regarding the objects.

2. The method of claim 1, wherein the management information includes one or more of timing of one or more processes, timing of a transfer from a first point to a second point, tracking of missing objects, and tracking movement of the one or more objects.

3. The method of claim 1, further comprising accessing the central database by a management system for managing product flow.

4. The method of claim 1, further comprising accessing the central database by a management system and providing a notification of arrival or departure.

5. The method of claim 1, further comprising accessing the central database by a management system and creating a history report of the objects.

6. The method of claim 1, further comprising accessing the central database by a management system and deriving a spare inventory report.

7. A method for tracking an object, the method comprising:

attaching a radio frequency identification (RFID) tag to each of a plurality of objects, the RFID tag having identifying information stored thereon;

associating a database entry for the objects and the corresponding RFID tags in a central database;

exciting a plurality of sensing antennas by a corresponding plurality of readers, wherein each sensing antenna is provided with a location identifier;

receiving the identifying information at the readers from at least some of the corresponding RFID tags that are within communication range of the excited sensing antennas;

determining the RFID tags from which identifying information is not received at the readers;

in the event that the identifying information is not received from at least one of the RFID tags that are within communication range of the excited sensing antennas, determining whether a current iteration count for determining if identifying information is received at the readers is above a limit for the number of iterations;

in the event that the current iteration count for determining if the identifying information is received at the readers is not above the limit for the number of iterations, incrementing the iteration count and disabling and then enabling a driver for each sensing antenna;

in response to enabling the drivers for the sensing antennas, receiving by the respective readers the identifying information from each RFID tag that is within communication range of the excited sensing antennas;

determining a storage location of each object based on the identifying information of the corresponding RFID tag and the location identifier of the sensing antenna that is positioned closest to the object relative to the other sensing antennas;

repeatedly updating the database entry using the identifying information to access the database entry, the updating including storing the storage location of each object having an associated RFID tag that provided the identifying information to the corresponding readers;

accessing the database entry to retrieve one or more data elements associated with the RFID tag or the objects; and

generating one or more reports regarding the RFID tag or the objects.

8. The method of claim 7, wherein the one or more reports includes one or more of timing of one or more processes, timing of a transfer from a first point to a second point, tracking of missing objects, and tracking movement of the one or more objects.

9. The method of claim 7, further comprising generating a notification of arrival or departure of the RFID tag or the objects.

10. The method of claim 7, wherein the one or more reports includes a history report of the objects.

11. The method of claim 7, wherein the one or more reports includes a spare inventory report.

12. A system comprising:

a radio frequency identification (RFID) tag attached to each of a plurality of objects;

a plurality of interrogators positioned separately at a plurality of locations, wherein;

each of the interrogators is configured to perform wireless communications with the RFID tags via a corresponding sensing antenna,

each sensing antenna is provided with a location identifier,

each interrogator excites the corresponding sensing antennas and receives identifying information from each RFID tag that is within communication range of the corresponding sensing antennas,

the RFID tags from which identifying information is not received at the interrogators are determined;

in the event that the identifying information is not received from at least one of the RFID tags, a determination is made whether a current iteration count for determining if identifying information is received at the interrogators is above a limit for the number of iterations;

in the event that the current iteration count for determining if the identifying information is received at the interrogators is not above the limit for the number of iterations, the iteration count is incremented and a driver for each sensing antenna is disabled and then enabled;

in response to enabling the drivers for the sensing antennas, the identifying information is received by the respective interrogators from each RFID tag that is within communication range of the excited sensing antennas;

a storage location of each object is determined based on the identifying information of the corresponding RFID tag and the location identifier of the sensing antenna that is positioned closest to the object relative to the other sensing antennas; and

a database having a database entry associated with the one or more objects of the RFID tag, the database entry to be updated by the respective interrogators to indicate the storage locations of the objects, wherein the database is configured to provide inventory management information regarding the objects.

13. The system of claim 12, wherein the management information includes one or more of timing of one or more processes, timing of a transfer from a first point to a second point, and tracking of missing objects.

14. The system of claim 12, further comprising a management system for managing product flow, the management system to provide access to the database.

15. The system of claim 12, further comprising a management system to provide access to the database, and to provide a notification of arrival or departure of the objects.

16. The system of claim 12, further comprising a management system to create a history report of the objects and to provide access to the database.

17. A method to manage inventory, the method comprising:

providing a plurality of storage locations;

attaching a plurality of radio frequency identification (RFID) tags to a plurality of items;

placing the items on at least some of the storage locations;

exciting a plurality of sensing antennas by a corresponding plurality of interrogators, wherein each sensing antenna is provided with a location identifier;

receiving identifying information at the interrogators from at least some of the corresponding RFID tags that are within communication range of the excited sensing antennas;

determining the RFID tags from which identifying information is not received at the interrogators;

in the event that the identifying information is not received from at least one of the RFID tags that are within communication range of the excited sensing antennas, determining whether a current iteration count for determining if identifying information is received at the interrogators is above a limit for the number of iterations;

in the event that the current iteration count for determining if the identifying information is received at the interrogators is not above the limit for the number of iterations, incrementing the iteration count and disabling and then enabling a driver for each sensing antenna;

in response to enabling the drivers for the sensing antennas, receiving by the respective interrogators the identifying information from each RFID tag that is within communication range of the excited sensing antennas; and

determining storage locations of the items based on the identifying information of the corresponding RFID tag and the location identifier of the sensing antenna that is positioned closest to the item relative to the other sensing antennas.

18. The method of claim 17, further comprising:

positioning the sensing antennas in vicinity of the plurality of storage locations to determine the storage locations of the items based on limited communication ranges of the sensing antennas.

19. The method of claim 18, wherein the plurality of storage locations comprise flat components on which the items are to be placed.

20. The method of claim 19, wherein the sensing antennas are integrated within the flat components.

21. The method of claim 20, wherein the flat components comprise a shelf, pallet, bench, or table.

22. The method of claim 18, further comprising:

connecting the sensing antennas to the corresponding interrogators via cable and jack.

23. The method of claim 17, wherein the storage locations of the items are real time locations of the items.

24. The method of claim 23, further comprising:

updating a central database to store the real time locations of the items.

25. The method of claim 24, further comprising:

providing a graphics display of the real time locations of the items.

26. The method of claim 23, further comprising:

determining an amount of time of an operation based on the real time locations of the items.

27. The method of claim 17, wherein each of the storage locations of the items has resolution down to individual shelf and position.

28. The method of claim 17, wherein the plurality of storage locations are located within a warehouse.

29. A system to manage inventory, the method comprising:

a plurality of radio frequency identification (RFID) tags attached to a plurality of items;

a plurality of storage locations for the items;

a plurality of sensing antennas located at the plurality of storage locations, wherein each sensing antenna is provided with a location identifier;

one or more interrogators connected to the sensing antennas to interrogate the RFID tags, wherein;

each interrogator excites the corresponding sensing antennas and receives identifying information from each RFID tag that is within communication range of the corresponding sensing antennas,

the RFID tags from which identifying information is not received at the interrogators are determined,

in the event that the identifying information is not received from at least one of the RFID tags, a determination is made whether a current iteration count for determining if identifying information is received at the interrogators is above a limit for the number of iterations,

in the event that the current iteration count for determining if the identifying information is received at the interrogators is not above the limit for the number of iterations, the iteration count is incremented and a driver for each sensing antenna is disabled and then enabled,

in response to enabling the drivers for the sensing antennas, the identifying information is received by the respective interrogators from each RFID tag that is within communication range of the excited sensing antennas, and

in response to receiving the identifying information, the storage location of each item is determined based on the identifying information of the corresponding RFID tag and the location identifier of the sensing antenna that is positioned closest to the item relative to the other sensing antennas; and

a database coupled with the one or more interrogators to store the determined storage locations of the items.

30. The system of claim 29, further comprising:

a plurality of tuned tank circuit co-located with the plurality of sensing antennas.

31. The system of claim 29, wherein the sensing antennas have a reduced operating range.

32. The system of claim 31, wherein the reduced operating range is on an order of two inches.

33. The system of claim 31, further comprising:

a plurality of ferrous cover plates positioned a predetermined distance from the sensing antennas to reduce the operating range.

34. A method to track an item, the method comprising:

attaching a radio frequency identification (RFID) tag to an item, the RFID tag storing identifying information of the item;

distributing a plurality of sensing antennas to a plurality of locations, the sensing antennas connected to one or more interrogators, wherein each sensing antenna is provided with a location identifier; and

tracking real time locations of the item via the one or more interrogators polling the RFID tag using the plurality of sensing antennas, wherein the tracking comprises;

exciting the plurality of sensing antennas by the corresponding interrogators;

receiving identifying information at the interrogators from at least some of the corresponding RFID tags that are within communication range of the excited sensing antennas;

determining the RFID tags from which identifying information is not received at the interrogators;

in the event that the identifying information is not received from at least one of the RFID tags that are within communication range of the excited sensing antennas, determining whether a current iteration count for determining if identifying information is received at the interrogators is above a limit for the number of iterations;

in the event that the current iteration count for determining if the identifying information is received at the interrogators is not above the limit for the number of iterations, incrementing the iteration count and disabling and then enabling a driver for each sensing antenna;

in response to enabling the drivers for the sensing antennas, receiving by the respective interrogators the identifying information from each RFID tag that is within communication range of the excited sensing antennas; and

determining the real time locations of the item by repeatedly determining a real time location of the item based on the identifying information of the corresponding RFID tag and the location identifier of the sensing antenna that is positioned closest to the item relative to the other sensing antennas.

35. The method of claim 34, further comprising:

determining an amount of time of an operation based on the real time locations of the item.

36. The method of claim 35, further comprising:

providing a graphics display of the real time locations of the item.

37. The method of claim 34, further comprising:

storing tracked real time locations of the item in a database; and

providing history information related to the item using the database.

38. The method of claim 37, wherein the history information comprises a transfer time of the item between two locations or movement of the item.

39. A system to track an item, the system comprising:

a plurality of sensing antennas at plurality of locations, wherein each sensing antenna is provided with a location identifier;

one or more interrogators connected to the sensing antennas;

a radio frequency identification (RFID) tag attached to an item, the RFID tag storing identifying information of the item, wherein;

each interrogator excites the corresponding sensing antennas and receives the identifying information from each RFID tag that is within communication range of the corresponding sensing antennas,

the RFID tags from which identifying information is not received at the interrogators are determined,

in the event that the identifying information is not received from at least one of the RFID tags, a determination is made whether a current iteration count for determining if identifying information is received at the interrogators is above a limit for the number of iterations,

in the event that the current iteration count for determining if the identifying information is received at the interrogators is not above the limit for the number of iterations, the iteration count is incremented and a driver for each sensing antenna is disabled and then enabled, and

in response to enabling the drivers for the sensing antennas, the identifying information is received by the respective interrogators from each RFID tag that is within communication range of the excited sensing antennas; and

a database coupled to the one or more interrogators to track real time locations of the item by repeatedly determining a real time location of the item based on the identifying information of the corresponding RFID tag and the location identifier of the sensing antenna that is positioned closest to the item relative to the other sensing antennas.

40. The system of claim 39, further comprising:

a plurality of tuned tank circuit co-located with the plurality of sensing antennas.

41. The system of claim 39, wherein the one or more interrogators is connected to the sensing antennas via jack.

42. The system of claim 39, wherein the sensing antennas are magnetically preloaded to reduce sensitivity.