System and method of enhanced RFID transport device sensor network

• US 8,120,482 B2
• Filed: 08/22/2008
• Issued: 02/21/2012
• Est. Priority Date: 08/24/2007
• Status: Active Grant

• Current Assignee: Walmart Apollo, LLC (WalMart Inc.)
• Original Assignee: Wal-Mart Stores Texas LLC (WalMart Inc.)
• Inventors: Ulrich, Richard Bennett
• Primary Examiner(s): Bugg, George
• Assistant Examiner(s): LAI, ANNE VIET NGA
• Application Number:
  US12/197,059
• Publication Number:
  US 20090212915A1
• Time in Patent Office: 1,278 Days
• Field of Search: 340/5.92, 340/572.1, 340/572.4, 340/539.13, 34053921-53923, 340/573.1, 340/825.49, 340/8.1, 235/385, 235/384, 705/28, 705/330, 705/333, 700213-215, 700/217, 700/219, 700/221, 700/224
• US Class Current: 340/539.22
• CPC Class Codes: B66F 9/0755 Position control; Position detectors
• CPC Class Codes: G06K 17/0022 arrangements or provisious for transferring data to distant stations, e.g. from a sensing device "transfer between computer elements G06F13/00 "; data-transmission H04L
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders

Abstract

A mobile sensor system and method for managing inventory of a store includes at least one radio frequency identification (RFID) scanner for receiving readings from RFID tags, at least one external sensors for detecting at least one external events other than RF signals from the RFID tags, and a processor configured to update an RFID database for storing the readings from the RFID tags, wherein the update is based on a correlation function of the readings from the RFID tags and the external events detected at the at least one external sensors.

Claims

1. A mobile sensor system for managing inventory of a store, comprising:

at least one radio frequency identification (RFID) scanner for receiving readings from RFID tags;

at least one external sensor for detecting external events other than RF signals from the RFID tags; and

a processor configured to;

determine a start of a time window based on a first external event detected by the at least one external sensor and an end of the time window based on a second external event detected by the at least one external sensor; and

detect stray readings based on the readings from the RFID tags acquired between the start and end of the time window.

2. The mobile sensor system of claim 1, wherein the mobile sensor system is situated on a transport device.

3. The mobile sensor system of claim 1, wherein the readings from the RF tags include at least one of a unique RFID tag identification and a radio frequency (RF) signal strength index.

4. The mobile sensor system of claim 1, wherein the RFID tags include product RFID tags for identifying products and locational RFID tags for identifying locations in the store.

5. The mobile sensor system of claim 4, wherein the RFID database includes relations between product RFID tags and locational RFID tags.

6. The mobile sensor system of claim 5, wherein a virtual pallet RFID tag is assigned to the product RFID tags to be stored in the RFID database, the virtual pallet RFID tag being determined based on the readings within the time window.

7. The mobile sensor system of claim 4, wherein the locations in the store include a shelf, a pallet and a ground area.

8. The mobile sensor system of claim 1, wherein the at least one external sensor includes at least one of a proximity sensor, a laser sensor and an accelerometer sensor.

9. The mobile sensor system of claim 1, wherein the at least one external event includes at least one of a load on and a load off a transport device detected at the at least one external sensor.

10. The mobile sensor system of claim 1, wherein the at least one external event includes at least one of a transport device moving forward, backward, and standing still detected at the at least one external sensor.

11. The mobile sensor system of claim 1, wherein the at least one external event includes a load-carrying part of a transport device being vertically above a threshold or being vertically below a threshold detected at the at least one external sensor.

12. The mobile sensor system of claim 1, wherein the start of the time window is based on a load on a transport device external event and the end of the time window is based on a load off the transport device external event.

13. The mobile sensor system of claim 1, wherein a number of the readings from the RFID tags within the time window determines which reading from an RFID tag is a stray reading.

14. The mobile sensor system of claim 1, further comprising:

a data recording device for recording readings from RFID tags and the at least one external event; and

a wireless data transmission link linking the data recording device to the processor.

15. The mobile sensor system of claim 1, wherein the store includes one of a retail store, a warehouse store, and a distribution center.

16. A method of using at least one RFID scanner and at least one external sensor other than the at least one RFID scanner for managing inventory of a store, comprising:

receiving readings from RFID tags;

detecting a first external event;

determining a start of a time window based on the first external event detected by the at least one external sensor;

detecting a second external event;

determining an end of the time window based on the second external event detected by the at least one external sensor; and

detecting stray readings based on the readings from the RFID tags acquired between the start and end of the time window.

17. The method of claim 16, wherein the start of the time window is based on a load on a transport device external event and the end of the time window is based on a load off the transport device external event.

18. A machine-readable non-transitory medium stored thereon executable codes that, when executed, performs a method of using at least one RFID scanner and at least one external sensor other than the at least one RFID scanner for managing inventory of a store, the method comprising:

receiving readings from RFID tags;

detecting a first external event;

determining a start of a time window based on the first external event detected by the at least one external sensor;

detecting a second external event;

determining an end of the time window based on the second external event detected by the at least one external sensor; and

detecting stray readings based on the readings from the RFID tags acquired between the start and end of the time window.