Pluggable small form-factor UHF RFID reader

• US 10,025,959 B2
• Filed: 12/29/2016
• Issued: 07/17/2018
• Est. Priority Date: 09/01/2010
• Status: Active Grant

• Current Assignee: Quake Global, Inc.
• Original Assignee: Quake Global, Inc.
• Inventors: Barvick, Scott, Krishna, Pattabhiraman, Shibuya, Hiroto
• Primary Examiner(s): KING, CURTIS J
• Application Number:
  US15/393,970
• Publication Number:
  US 20170109554A1
• Time in Patent Office: 565 Days
• Field of Search: None
• CPC Class Codes: G06F 16/93 Document management systems
• CPC Class Codes: G06K 7/10009 sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications

Abstract

Systems and methods for reading Radio Frequency Identified (RFID) tags. In an embodiment, an enclosure having, within it, an antenna and processor is provided. The processor may be configured to record tag observations for tag identifiers received by the antenna from RFID tags. For one or more time intervals, tag observations may be identified which satisfy a tag filter, and a confidence that RFID tags satisfying the tag filter were in the field of view of the antenna during the time interval may be computed based on the identified tag observations. According to an embodiment, reports for tag filters may be then generated using the computed confidences, and these reports may be transmitted to an external system over a network.

Claims

1. A system for reading Radio Frequency Identifier (RFID) tags, the system comprising:

an enclosure comprising a front surface and a back surface, wherein the back surface comprises a recess and a plug which is collapsible into the recess;

at least one antenna within the enclosure and configured to receive one or more tag identifiers from one or more RFID tags; and

at least one processing unit housed within the enclosure and configured to,

for each of one or more of the received one or more tag identifiers, record a tag observation comprising a tag identifier, a timestamp representing a time at which the tag identifier was received, and a signal strength at which the tag identifier was received,

for each of a plurality of time intervals,

for each of one or more tag filters,

compute a confidence that RFID tags satisfying a tag filter were in a field of view of the at least one antenna during a time interval, wherein the confidence is computed based on one or more recorded tag observations which satisfy the tag filter and which occurred during the time interval,

compute one or more statistics based on the signal strength of the one or more recorded tag observations which satisfy the tag filter and which occurred during the time interval,

determine whether or not to transmit a report for the tag filter by, if a reporting interval for the tag filter has not expired, determine to not transmit the report for the tag filter, and, if the reporting interval for the tag filter has expired and if a difference between one or more of the confidence and the one or more statistics exceeds a threshold, determine to transmit the report for the tag filter, and,

if it is determined to transmit the report for the tag filter, generate the report for the tag filter, and

transmit one or more reports generated for one or more of the one or more tag filters to an external system via at least one network.

2. A system for reading Radio Frequency Identifier (RFID) tags, the system comprising:

at least one antenna configured to receive one or more tag identifiers from one or more RFID tags; and

at least one processing unit configured to,

for each of one or more of the received one or more tag identifiers, record a tag observation comprising a tag identifier, a timestamp representing a time at which the tag identifier was received, and a signal strength at which the tag identifier was received,

for each of one or more time intervals, for each of one or more tag filters, identify one or more tag observations which satisfy a tag filter and which occurred during a time interval, and compute a confidence that RFID tags satisfying the tag filter were in a field of view of the at least one antenna during the time interval based on the identified one or more tag observations,

generate one or more reports for one or more of the one or more tag filters using one or more computed confidences, and

transmit the generated one or more reports to an external system via at least one network.

3. The system of claim 2, wherein the enclosure is configured to obtain power via a plurality of sources.

4. The system of claim 3, wherein the plurality of sources comprise two or more of an Alternating Current (AC) outlet, an external AC/Direct Current (DC) converter, and Power over Ethernet (PoE).

5. The system of claim 3, wherein the at least one antenna comprises a radiating patch, a ground plane, and a dielectric material between the radiating patch and the ground plane.

6. The system of claim 2, further comprising an enclosure having a back surface comprising a recess with two or more sockets, and wherein the system further comprises a plug assembly configured to removably connect with each of the two or more sockets such that the plug assembly may be removed from one of the two or more sockets, rotated, and connected to a different one of the two or more sockets.

7. The system of claim 2, wherein generating one or more reports for one or more of the one or more tag filters comprises, for each of the one or more time intervals, for each of the one or more tag filters:

determining whether or not to report the tag filter, and,

if it is determined to report the tag filter, generating a report comprising the computed confidence.

8. The system of claim 7, wherein the report further comprises a peak signal strength for the identified one or more tag observations, and a ratio of a standard deviation of signal strengths to average signal strength for the identified one or more tag observations.

9. The system of claim 7, wherein the one or more time intervals comprises a plurality of time intervals, and wherein determining whether or not to report the tag filter comprises:

if a predetermined reporting interval for the tag filter has not expired, determine to not report the tag filter, and,

if the predetermined reporting interval has expired,

determining at least one difference between the identified one or more tag observations of the time interval and the identified one or more tag observations of a previous time interval,

if the at least one difference exceeds a predetermined threshold, determine to report the tag filter, and,

if the at least one difference does not exceed the predetermined threshold, determine to not report the tag filter.

10. The system of claim 9, wherein the at least one difference comprises a difference between one or more of the computed confidence, a peak signal strength, and a ratio of a standard deviation of signal strengths to average signal strength for the time interval and the previous time interval.

11. A method comprising using at least one hardware processor within a pluggable housing to:

receive one or more tag identifiers from one or more RFID tags via at least one antenna;

for each of the one or more tag identifiers, record a tag observation comprising a tag identifier, a timestamp representing a time at which the tag identifier was received, and a signal strength at which the tag identifier was received; and

for each of one or more time intervals, for each of one or more tag filters, identify one or more tag observations which satisfy a tag filter, and compute a confidence that RFID tags satisfying the tag filter were in a field of view of the at least one antenna during the time interval based on the identified one or more tag observations.

12. The method of claim 11, wherein the one or more tag filters comprise one or more of a binary bit pattern indicating one or more significant bits, a full tag specification, and a type of asset.

13. The method of claim 11, wherein computing a confidence comprises computing a probability based on a count of the identified one or more tag observations.

14. The method of claim 11, wherein the confidence is computed based on one or more low-pass-filter values for one or more time periods between successive ones of the identified one or more tag observations.

15. The method of claim 11, further comprising using the at least one hardware processor to, for each of the one or more time intervals, for each of the one or more tag filters, compute one or more statistics based on the signal strength of the identified one or more tag observations.

16. The method of claim 15, wherein the one or more statistics comprise one or more of a peak signal strength, a standard deviation of signal strengths, an average signal strength, and a ratio of the standard deviation of signal strengths to the average signal strength.

17. The method of claim 11, further comprising generating one or more reports for one or more of the one or more tag filters, wherein generating a report comprises, for each of the one or more time intervals, for each of the one or more tag filters:

determining whether or not to report the tag filter, and,

if it is determined to report the tag filter, generating a report comprising the computed confidence.

18. The method of claim 17, wherein the report further comprises a peak signal strength for the identified one or more tag observations, and a ratio of a standard deviation of signal strengths to average signal strength for the identified one or more tag observations.

19. The method of claim 17, wherein the one or more time intervals comprises a plurality of time intervals, and wherein determining whether or not to report the tag filter comprises:

if a predetermined reporting interval for the tag filter has not expired, determine to not report the tag filter, and,

if the predetermined reporting interval has expired,

determining at least one difference between the identified one or more tag observations of the time interval and the identified one or more tag observations of a previous time interval,

if the at least one difference exceeds a predetermined threshold, determine to report the tag filter, and,

if the at least one difference does not exceed the predetermined threshold, determine to not report the tag filter.

20. The method of claim 19, wherein the at least one difference comprises a difference between one or more of the computed confidence, a peak signal strength, and a ratio of a standard deviation of signal strengths to average signal strength for the time interval and the previous time interval.