Method and system for performing mobile RFID asset detection and tracking

• US 8,477,013 B2
• Filed: 08/31/2007
• Issued: 07/02/2013
• Est. Priority Date: 08/31/2006
• Status: Expired due to Fees

• Current Assignee: CHECKPOINT SYSTEMS, INC. (CCL Industries Incorporated)
• Original Assignee: CHECKPOINT SYSTEMS, INC. (CCL Industries Incorporated)
• Inventors: Sarma, Sanjay, Subirama, Brian
• Primary Examiner(s): Zimmerman, Brian
• Assistant Examiner(s): YANG, JAMES J
• Application Number:
  US11/849,260
• Publication Number:
  US 20080198001A1
• Time in Patent Office: 2,132 Days
• Field of Search: 340/825, 340/825.36, 340/825.49, 340 101- 106, 340/1.1, 3405721-5729, 340/8.1, 340/568.5, 235375-385
• US Class Current: 340/8.1
• 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 relative locations of assets within a prescribed region, the method comprising:

(a) providing a prescribed region having a plurality of assets disposed within said prescribed region and whose relative locations within said prescribed region are unknown;

(b) disposing a first wireless communication beacon device within said prescribed region at a first location and disposing a second wireless communication beacon at a second location within said prescribed region, different from said first location, said disposing of said first and second wireless communication beacon devices defining a sub-region of said prescribed region that is located between said first and second wireless communication beacon devices;

(c) associating respective wireless communication devices with each one of said plurality of assets to form a plurality of wireless communication asset tracking devices;

(d) traversing said prescribed region to wirelessly detect said wireless communication beacon devices and at least one of said wireless communication asset tracking devices, said traversing comprising wirelessly detecting said first wireless communication beacon device, followed by detecting one or more wireless communication asset tracking devices, followed by detecting said second wireless communication beacon device; and

(e) inferring that the relative locations of said one or more wireless communication asset tracking devices are within said sub-region.

2. 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 one or more wireless communication asset tracking devices.

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

4. A method according to claim 3, wherein said mobile RFID reader/writer device traverses said prescribed region under operator control.

5. A method according to claim 3, wherein said mobile RFID reader/writer device traverses said prescribed region autonomously.

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

7. A method according to claim 6, wherein each passive identification device is an RFID tag.

8. A method according to claim 1, wherein said step (d) 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 remote host computer for processing therein.

9. A method according to claim 1, wherein said step of detecting said second wireless communication beacon device comprises said second wireless communication beacon device emitting a response signal that comprises at least a unique identification code and wherein said response signal from said second wireless communication beacon device comprises an indicia of response signal strength, and wherein said indicia is compared to a predetermined threshold.

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

building a correlation table correlating a known position of said first and second wireless communication beacon devices with an identification code.

11. A method according to claim 1, wherein said inferring 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.

12. A method according to claim 11, wherein said look-up table is comprised of association pairs of wireless communication beacon devices and sections within said prescribed region.

13. 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 for detection by said mobile RFID reader/writer, each one of said plurality of RFID asset tracking transponders being associated with a respective one of said assets and wherein each one of said assets is disposed within said prescribed region and whose relative location within said prescribed region is unknown;

(d) a host computer, remotely-located from said RFID reader/writer, 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) infer relative locations of assets within said prescribed region based on receipt by said RFID reader/writer of a first location transponder response signal, followed by receipt of asset tracking transponder response signals, and followed by receipt of a second location transponder response signal; and

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