Inventory tracking using RFID

Patent metadata

Field	Value
Publication number	US-10262172-B1
Application number	US-201514869861-A
Country	US
Kind code	B1
Filing date	Sep 29, 2015
Priority date	Sep 29, 2015
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

A storage unit includes a support bar for hanging items and an RFID antenna provided within a predefined distance of the support bar. When the items hanging from the support bar are adorned with RFID tags, and the RFID antenna emits electromagnetic fields in a direction of the support bar. RFID signals identifying the items are transmitted from the RFID tags to the RFID antenna, thereby enabling a placement or a removal of an item to be automatically registered, or an accounting of the available items to be automatically performed. The RFID antenna may be a portion of a transmission line that uses shields and/or dielectric materials to shape the electromagnetic fields toward a predefined direction, and the locations of items bearing RFID tags on the support bar may be determined by varying the phase of the emitted radiofrequency and determining strengths of RFID signals when the electromagnetic fields are emitted at varying phases.

First claim

What is claimed is:

1. An inventory area of a materials handling facility comprising:
a pegboard having a plurality of openings provided in a pattern;
a storage unit releasably mounted to the pegboard, wherein the storage unit comprises:
a base;
a support bar having a proximal end mounted to a front face of the base and a free distal end, wherein a first section of the support bar comprising the proximal end extends substantially perpendicular to the front face of the base, and wherein a second section of the support bar comprising the free distal end is canted upward with respect to the first section;
an RFID antenna having a proximal end mounted to the front face of the base above the support bar, wherein the RFID antenna extends substantially perpendicular to the front face of the base and substantially parallel to the first section of the support bar, and wherein the RFID antenna is coupled to an RFID reader; and
at least one peg extending from a rear face of the base, wherein the at least one peg extends substantially perpendicular to the rear face of the base, and wherein the at least one peg extends through at least one of the plurality of openings of the pegboard; and

an item suspended from the support bar, wherein the item comprises:
an extension having an upper portion and a lower portion;
an RFID tag provided in the upper portion of the extension, wherein the RFID tag is programmed to transmit an RFID signal to the RFID antenna when the RFID tag senses an electromagnetic field emitted by the RFID antenna; and
a hole provided in a lower portion of the extension, wherein the support bar is extended through the hole,

wherein the upper portion of the extension is positioned between the RFID antenna and the support bar.

2. The inventory area of claim 1 , further comprising a detection circuit associated with the at least one of the plurality of openings of the pegboard,
wherein the detection circuit comprises a voltage source, a resistor and a switch associated with the at least one of the plurality of openings,
wherein the detection circuit is configured to generate a first voltage signal when the at least one peg is inserted into the at least one of the plurality of openings, and
wherein the detection circuit is configured to generate a second voltage signal when the at least one peg is not inserted into the at least one of the plurality of openings.

3. The inventory area of claim 1 , wherein the RFID antenna comprises a conductive rod coupled to the RFID reader,
wherein the conductive rod is configured to emit an electromagnetic field in at least a first radial direction toward the support bar, and
wherein a strength of the electromagnetic field is selected based at least in part on a predefined vertical distance separating the support bar and the conductive rod.

4. A method comprising:
causing an electromagnetic field to be emitted by an RFID antenna provided above a support bar, wherein the RFID antenna is mounted perpendicular to a panel, and wherein at least a portion of the RFID antenna is in parallel with at least a portion of the support bar at a first predefined vertical distance from the portion of the support bar;
receiving, by the RFID antenna, a first RFID signal from a first RFID tag;
interpreting contents of the first RFID signal using at least one computer processor;
identifying first information regarding the first RFID tag based at least in part on the interpreted contents of the first RFID signal using the at least one computer processor;
identifying a first item bearing the first RFID tag based at least in part on the first information regarding the first RFID tag using the at least one computer processor;
determining that one of the first item bearing the first RFID tag is disposed on the support bar based at least in part on the first RFID signal using the at least one computer processor;
determining a location of the support bar on the panel using at least one computer processor; and
storing second information in at least one data store, wherein the second information associates the one of the first item bearing the first RFID tag with the support bar,
wherein the second information associates the one of the first item bearing the RFID tag with the location.

5. The method of claim 4 , further comprising:
wherein storing the second information comprises at least one of:
adding an identifier of the first item to a record of inventory stored in the at least one data store; or
increasing a quantity of the first item in the record of inventory stored in the at least one data store.

6. The method of claim 4 , wherein a strength of the electromagnetic field is selected based at least in part on the first predefined vertical distance.

7. The method of claim 4 , wherein the panel comprises a plurality of antenna connections, and
wherein determining the location of the support bar on the panel further comprises:
receiving a voltage signal at a detection circuit, wherein the voltage signal corresponds to a voltage level at one of the plurality of antenna connections;
identifying the one of the plurality of antenna connections to which the voltage signal corresponds using the at least one computer processor;
determining that the one of the plurality of antenna connections is associated with the location using the at least one computer processor; and
determining that the one of the first item is disposed on the support bar at the location based at least in part on the voltage signal using the at least one computer processor.

8. The method of claim 4 , wherein the one of the first item further comprises a first extension having an upper section and a lower section,
wherein the lower section of the first extension comprises a first opening, and
wherein the first RFID tag is affixed to the upper portion of the first extension between the first opening and an upper edge of the first extension.

9. The method of claim 4 , wherein the support bar comprises a base having at least one peg extending substantially perpendicular to a rear face of the base, and
wherein the method further comprises:
inserting the at least one peg into at least one of a plurality of openings of a panel.

10. The method of claim 4 , further comprising:
determining that the first RFID signal is no longer received by the RFID antenna;
determining that the one of the first item bearing the first RFID tag is no longer disposed on the support bar based at least in part on the first RFID signal; and
storing third information in at the at least one data store, wherein the third information dissociates the one of the first item bearing the first RFID tag from the location.

11. The method of claim 10 , wherein the one of the first item further comprises a first extension having an upper section and a lower section,
wherein the lower section of the first extension comprises a first opening,
wherein the first RFID tag is affixed to the upper portion of the first extension between the first opening and an upper edge of the first extension, and
wherein the method further comprises:
lifting the one of the first item bearing the first RFID tag from the support bar; and
removing the first opening of the first extension from the free distal end of the support bar.

12. The method of claim 4 , wherein receiving the first RFID signal further comprises:
receiving, by the RFID antenna, a plurality of RFID signals, wherein the plurality of RFID signals includes the first RFID signal,
wherein interpreting the contents of the first RFID signal further comprises:
interpreting contents of each of the plurality of RFID signals using the at least

Assignees

• Amazon Tech Inc

Inventors

• Niranjayan Somasundaram
• Hahn Camerin
• Huebner Ronald Eugene

Classifications

• G06K7/10366

  the interrogation device being adapted for miscellaneous applications · CPC title

• G06K7/10376

  the interrogation device being adapted for being moveable · CPC title

• G06Q10/087

  Inventory or stock management, e.g. order filling, procurement or balancing against orders · CPC title

• G06K7/10425 Primary

  the interrogation device being arranged for interrogation of record carriers passing by the interrogation device · CPC title

• G06K7/10326

  the antenna being of the very-near field type, e.g. capacitive · CPC title