RFID System With A Mobile RFID Reader

• US 20090195358A1
• Filed: 09/11/2008
• Published: 08/06/2009
• Est. Priority Date: 02/04/2008
• Status: Active Grant

• Current Assignee: Ent Services Development Corporation LP (DXC Technology Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Gupta, Manish, Vennelakanti, Ravigopal
• Granted Patent: US 8,063,738 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• 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 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders

Abstract

An RFID system includes a pair of guide tracks located on opposite boundaries of at least one zone. A channel is movably attached to the guide tracks and is configured to move along the guide tracks through the at least one zone. A mobile RFID reader is movably attached to the channel and the mobile RFID reader is paused at a plurality of read points to scan for RFID tags located. The read points are determined by an arrangement of a plurality of hexagonal areas which are grouped together to create a combined area, where the combined area is aligned with the predefined area to define locations of the plurality of hexagonal areas, and where substantially central locations of each hexagonal area represent the plurality of read points.

Claims

1. An RFID system comprising:

a pair of guide tracks located on opposite boundaries of at least one zone, wherein the at least one zone is at least a portion of a predefined area;

a channel movably attached to the guide tracks, wherein the channel is configured to move along the guide tracks through the at least one zone; and

a mobile RFID reader movably attached to the channel, wherein the mobile RFID reader is configured to move along the channel and pause at a plurality of read points within the at least one zone to scan for RFID tags located within the predefined area, wherein the plurality of read points are determined by an arrangement of a plurality of hexagonal areas which are grouped together to create a combined area, wherein the combined area is aligned with the predefined area to define locations of the plurality of hexagonal areas, and wherein substantially central locations of each hexagonal area represent the plurality of read points. (I am not sure whether the nexus between determining the read points and arranging hexagonal areas to create a combined area is clear)

2. The RFID system of claim 1, wherein the predefined area is a warehouse, which is configured to stores items associated with the RFID tags and the guide tracks are attached to a ceiling of the warehouse.

3. The RFID system of claim 1, wherein the plurality of read points are substantially optimized locations for reading RFID tags to obtain substantially complete coverage of the at least one zone while reducing an amount of redundant reads of the RFID tags.

4. The RFID system of claim 1, wherein the combined area is equal to or larger than the predefined area.

5. The RFID system of claim 4, wherein the hexagonal areas all have substantially the same dimensions and a distance from the center of each of the hexagonal areas to a vertex of each of the hexagonal areas substantially corresponds to a reading range of the RFID reader.

6. The RFID system of claim 1, further comprising:

a reader manager configured to facilitate the movement of the RFID reader between the plurality of read points, wherein the reader manager stores a map table containing both the relative and absolute coordinates of the plurality of read points.

7. The RFID system of claim 1, wherein at least one of the plurality of read points coincides with the position of at least one of the pair of guide tracks such that the mobile RFID reader is operable to read RFID tags located outside of the boundaries of the at least one zone.

8. The RFID system of claim 1, further comprising:

at least one of an area marker module configured to determine the position of the mobile RFID reader within the predefined area, a layout module configured to determine dimensions of the at least one zone, an obstacle position identifier configured to store data regarding obstacles in the predefined area, and a range and speed calibration module configured to monitor the movement of the mobile RFID reader.

9. The RFID system of claim 1, wherein the predefined area includes a second zone and, wherein the RFID system further comprises:

a second mobile RFID reader configured to move through the second zone and pause at a plurality of read points within the second zone to read RFID tags located within the second zone.

10. A method of scanning for RFID tags comprising:

arranging a plurality of hexagonal areas together to form a combined area, wherein each hexagonal area represents an area of coverage of a mobile RFID reader;

aligning the combined area with a predefined area to define locations of the plurality of hexagonal areas in the predefined area;

moving a channel along a pair of guide tracks, wherein the guide tracks are located on opposite boundaries of at least one zone, wherein the at least one zone is at least a portion of the predefined area;

moving the mobile RFID reader along the channel through at least a portion of the at least one zone;

pausing the mobile RFID reader at a read point within the at least one zone, wherein the read point comprises a substantially central location of a hexagonal area; and

scanning for RFID tags with the mobile RFID reader while the mobile RFID reader is paused at the read point.

11. The method of claim 10, wherein moving a channel along a pair of guide tracks comprises transmitting channel movement details from a zone controller to a channel controller, moving the mobile RFID reader along the channel comprises transmitting reader movement details from a zone controller to a reader controller, and scanning for RFID tags comprises reading information from RFID tags located within the predefined area.

12. The method of claim 10, further comprising:

determining the position of the mobile RFID reader within the predefined area to monitor the movement of the mobile RFID read with respect to the predefined area.

13. The method of claim 10, wherein the hexagonal areas all have substantially the same dimensions and a distance from the center of each of the hexagonal areas to a vertex of each of the hexagonal areas substantially corresponds to a reading range of the RFID reader.

14. The method of claim 10, wherein the guide tracks are attached to the ceiling of a warehouse and scanning for RFID tags comprises scanning for RFID tags located underneath the ceiling of the warehouse.

15. The method of claim 10, wherein the at least one zone includes a plurality of read points and the method further comprises:

moving the mobile RFID reader to another one of the plurality of read points;

pausing the mobile RFID reader at the another one of the plurality of read points; and

scanning for RFID tags at the another one of the plurality of read points.

16. The method of claim 10, wherein pausing the mobile RFID reader comprises stopping the mobile RFID reader at the read point for a duration of time while the mobile RFID reader scans for RFID tags.

17. The method of claim 10, further comprising:

determining the relative and absolute coordinates of the read point; and

storing the relative and absolute coordinates in a map table.

18. The method of claim 10, wherein the predefined area includes a second zone having a second mobile RFID reader and the method further comprises:

moving the second mobile RFID reader through the second zone such that a reading range of the second mobile RFID reader is not within a reading range of the mobile RFID reader.

19. A computer readable storage medium on which is embedded one or more computer programs, said one or more computer programs implementing a method for localizing a tag, said one or more computer programs comprising a set of instructions for:

arranging a plurality of hexagonal areas together to form a combined area, wherein each hexagonal area represents an area of coverage of a mobile RFID reader;

aligning the combined area with a predefined area to define locations of the plurality of hexagonal areas in the predefined area;

moving a channel along guide tracks, wherein the guide tracks are located on opposite boundaries of at least one zone, wherein the at least one zone is at least a portion of the predefined area in the combined area;

moving the mobile RFID reader along the channel through at least a portion of the at least one zone;

pausing the mobile RFID reader at a read point within the at least one zone, wherein the read point comprises a substantially central location of a hexagonal area; and

scanning for RFID tags with the mobile RFID reader while the mobile RFID reader is paused at the read point.

20. The computer readable storage medium of claim 19, further comprising a set of instructions for:

moving the mobile RFID reader to another one of the plurality of read points;

pausing the mobile RFID reader at the another one of the plurality of read points; and

scanning for RFID tags at the another one of the plurality of read points.