Method and System for Performing Mobile RFID Asset Detection and Tracking

• US 20080198001A1
• Filed: 08/31/2007
• Published: 08/21/2008
• Est. Priority Date: 08/31/2006
• Status: Active Grant

• Current Assignee: CHECKPOINT SYSTEMS, INC. (CCL Industries Incorporated)
• Original Assignee: CHECKPOINT SYSTEMS, INC. (CCL Industries Incorporated)
• Inventors: Sarma, Sanjay, Subirama, Brian
• Granted Patent: US 8,477,013 B2
• Time in Patent Office: Days
• US Class Current: 340/539.1
• CPC Class Codes: G01S 1/68 Marker, boundary, call-sign, or like beacons transmitting signals not carrying directional information
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders

Abstract

Systems and methods of using RFID tags and a mobile RFID reader device for determining a geographic position of assets within a prescribed region is provided. A method of inferring the geometric location of assets within a prescribed region comprises the steps of moving a mobile RFID reader through said prescribed region; wirelessly detecting, by the mobile RFID reader, a first RFID location transponder while moving through said prescribed region; wirelessly detecting, by the mobile RFID reader, at least one RFID asset tracking transponder while moving through said prescribed region; wirelessly detecting, by the mobile RFID reader, a second RFID location transponder while moving through said prescribed region; and determining the geographic location of assets associated with said at least one detected RFID asset tracking transponder based upon said detected first and second RFID location transponders and a known position and identification code of said first and second RFID location transponders.

Claims

1. A method for inferring a location of assets within a prescribed region, the method comprising:

(a) traversing said prescribed region to wirelessly detect wireless communication beacon devices and wireless communication asset tracking devices having assets attached thereto;

(b) wirelessly detecting a first wireless communication beacon device while traversing said prescribed region;

(c) wirelessly detecting at least one wireless communication asset tracking device while traversing said prescribed region;

(d) wirelessly detecting a second wireless communication beacon device while traversing said prescribed region;

(e) determining that said first and second detected wireless communication beacon devices are associated with a same sub-region within said prescribed region; and

(f) upon satisfying said determining step (e), inferring the location of assets attached to said at least one wirelessly detected wireless communication asset tracking device to be located within said sub-region.

2. A method according to claim 1, further comprising:

placing said wireless communication beacon devices at strategic locations throughout said prescribed region, prior to said traversing step (a).

3. A method according to claim 1, wherein each of said wireless communication asset tracking devices has an associated asset attached thereto.

4. A method according to claim 1, further comprising:

(i) upon not satisfying said determining step (e), determining whether the strength of a signal received from said wireless communication beacon device is above a pre-determined threshold;

(ii) upon not satisfying said determining step (i), ignoring the detection of the second wireless communication beacon device; and

(iii) upon satisfying said determining step (i), ignoring the detection of said wirelessly detected at least one wireless communication asset tracking device.

5. A method according to claim 1, wherein said traversing is performed using a mobile radio frequency identification (RFID) reader/writer device.

6. A method according to claim 5, wherein said mobile RFID reader/writer device traverses said prescribed region under operator control.

7. A method according to claim 5, wherein said mobile RFID reader/writer device traverses said prescribed region autonomously.

8. A method according to claim 1, wherein each wireless communication beacon device and each wireless communication asset tracking device is a passive identification device.

9. A method according to claim 8, wherein each passive identification device is an RFID tag.

10. A method according to claim 1, wherein said step (a) of traversing said prescribed region, further comprises:

continuously emitting an interrogation signal within a prescribed zone;

receiving response signals from detected wireless communication beacon devices and wireless communication asset tracking devices in response to said emitted detection signal;

forwarding said response signals to a host computer for processing therein.

11. A method according to claim 1, wherein said steps (b) and (d), further comprise:

wirelessly detecting a response signal from said detected first and second wireless communication beacon devices, wherein said response signal comprises at least a unique identification code and an indicia of response signal signal strength.

12. A method according to claim 1, further comprising:

building a correlation table correlating a known position of said plurality of RFID location transponders with an identification code.

13. A method according to claim 1, wherein said determining step (e), further comprises:

performing a table-lookup to determine if said first and second detected wireless communication beacon devices are associated with a same section of said prescribed region.

14. A method according to claim 13, wherein said look-up table is comprised of association pairs of wireless communication beacon devices and sections within said prescribed region.

15. A method for ensuring that a plurality of wireless communication devices are detected within a prescribed region, the method comprising:

placing one or more reference wireless communication devices in physically inaccessible locations throughout said prescribed region;

traversing said prescribed region to wirelessly detect each of said plurality of wireless communication devices, including said reference wireless communication devices; and

determining at the conclusion of said traversal that said plurality of wireless communication devices including said reference wireless communication devices were detected.

16. An RFID Mobile asset tracking system, comprising:

(a) a mobile RFID reader/writer configured to transmit/receive signals within a prescribed transmission/reception zone while moving through a prescribed region,

(b) a plurality of RFID location transponders configured to receive a mobile RFID reader signal and generate location transponder response signals based thereon, each of said plurality of RFID location transponders positioned at a respective location within said prescribed region for detection by said mobile RFID reader/writer;

(c) a plurality of RFID asset tracking transponders configured to receive said mobile RFID reader signal and generate asset tracking transponder response signals based thereon, each of said plurality of RFID asset tracking transponders positioned at a respective location within said prescribed region, fixedly attached to a single asset within said prescribed region, for detection by said mobile RFID reader/writer;

(d) a host computer communicatively coupled to said mobile RFID reader/writer to;

(i) receive said location transponder response signals and said asset tracking transponder response signals from said mobile RFID reader/writer,

(ii) determine a geographic location of assets within said prescribed region based on a known position of said plurality of RFID location transponders, a wireless detection of at least two RFID location transponders and at least one RFID asset tracking transponder in proximal location to said at least two RFID location transponders; and

(iii) identify unique identification codes associated with each of said RFID location transponders and said RFID asset tracking transponders.

17. An RFID Mobile asset tracking system according to claim 16, wherein said location transponder response signal comprises a unique identification code.

18. An RFID Mobile asset tracking system according to claim 16, wherein said asset tracking transponder signal comprises a unique identification code.