Interrogation, monitoring and data exchange using RFID tags

• US 7,053,777 B2
• Filed: 05/20/2005
• Issued: 05/30/2006
• Est. Priority Date: 10/26/1998
• Status: Expired due to Term

• Current Assignee: Identec Solutions AG
• Original Assignee: Identec Solutions, Inc. (Identec Solutions AG)
• Inventors: Allen, Barry
• Primary Examiner(s): Pope, Daryl C
• Application Number:
  US11/133,298
• Publication Number:
  US 20050219039A1
• Time in Patent Office: 375 Days
• Field of Search: 340/10.1, 340/505, 340/539.1, 340/539.11, 340/539.13, 340/572.1, 340/825.69, 340/825.72
• US Class Current: 340/572.1
• CPC Class Codes: G06K 19/0717 the sensor being capable of sensing environmental conditions such as temperature history or pressure
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support

Abstract

A method and apparatus for identification and monitoring of, and obtaining data relating to, products moving along a distribution path, including at least one RFID tag mountable to a product, or product carrier, and a plurality of interrogators spaced apart along the distribution path, wherein each interrogator of the plurality of interrogators cooperates in RF communication with the RFID tag when the RFID tag is in proximity to the each interrogator along the distribution path. Each interrogator interrogates the RFID tag during the RF communication so as to obtain unique data, unique to the RFID tag. The RFID tag and each interrogator each includes a transceiver and memory, the memory.

Claims

1. An apparatus for identification and monitoring of, and obtaining data relating to, products moving along a distribution path, comprising:

an RFID tag mountable to a product, or product carrier,

a plurality of interrogators spaced apart along said distribution path, wherein each interrogator of said plurality of interrogators cooperates in RF communication with said RFID tag when said RFID tag is in proximity to said each interrogator along said distribution path,

wherein said each interrogator interrogates said RFID tag during said RF communication so as to obtain unique data, unique to said RFID tag,

wherein said each interrogator communicates said unique data to a central data base,

a central database processor cooperating with said central database and communicating with said plurality of interrogators so as to obtain up-to-date data, including said unique data, from said RFID tag as said RFID tag progresses along said distribution path,

distributed processors along said distribution path also in communication with said central database processor so that said distributed processors may obtain feedback information and data from said central database no matter where said RFID tag is along said distribution path so as to obtain up-to-date product status data from said up-to-date data including said unique data,

wherein said RFID tag and said each interrogator each comprises a transceiver and memory, said memory cooperating with said transceiver.

2. The apparatus of claim 1 wherein said RFID tag further comprises a data gathering sensor.

3. The apparatus of claim 2 wherein said data gathering sensor is an environmental status sensor.

4. The apparatus of claim 3 wherein said environmental status sensor is a temperature sensor.

5. The apparatus of claim 1 wherein said plurality of interrogators include at least one choke point interrogator,

wherein said at least one choke point interrogator interrogates for ID'"'"'s of said RFID tag by means of time division multiplexing,

and wherein frame sizes within said time division multiplexing are adjusted by an interrogator processor calculating, so as to optimize said frame sizes by an optimizing frame size adjustment of said frame sizes according to, a collision rate between responses from said RFID tag in response to said interrogation from said choke point interrogator and responses from other RFID tags within a choke point communication range of said choke point interrogator.

6. The apparatus of claim 5 wherein said collision rate is determined by said choke point interrogator by said interrogator processor comparing:

(a) a cumulative first time period within said frame sizes wherein a signal strength detected by said choke point interrogator is increased so as to indicate transmission of responses from said RFID tag or said other RFID tags, with

(b) a cumulative second time period within said frame sizes corresponding to known valid responses received by said choke point interrogator from said RFID tag or said other RFID tags.

7. The apparatus of claim 6 wherein said interrogator processor calculates said optimizing frame size adjustment by increasing a total cumulative time within said frame sizes if said collision rate is higher than an optimal collision rate, and by decreasing said total cumulative time within said frame sizes if said collision rate is lower than said optimal collision rate.

8. The apparatus of claim 7 wherein said choke point interrogator interrogates said RFID tag and said other RFID tags within said choke point interrogator communication range in a rollcall until a statistical confidence level is obtained as determined by said choke point interrogator processor calculating a confidence level and said confidence level indicating that said RFID tag and said other RFID tags have all successfully been identified.

9. The apparatus of claim 1 wherein said distributed processors spaced along said distribution path and said plurality of interrogators are located at corresponding producer, shipment, warehousing, and retailing locations.

10. The apparatus of claim 1 wherein said communication with said central database processor is via the internet.

11. The apparatus of claim 7 wherein said optimal collision rate is in the range between 20–

30%.

12. The apparatus of claim 7 wherein said optimal collision rate is in the range between 10–

40%.

13. An apparatus for identification and monitoring of, and obtaining data relating to, products moving along a distribution path, comprising:

an RFID tag mountable to a product, or product carrier,

a plurality of interrogators spaced apart along said distribution path, wherein each interrogator of said plurality of interrogators cooperates in RF communication with said RFID tag when said RFID tag is in proximity to said each interrogator along said distribution path,

wherein said each interrogator interrogates said RFID tag during said RF communication so as to obtain unique data, unique to said RFID tag, wherein said RFID tag and said each interrogator each includes a transceiver and memory, said memory cooperating with said transceiver, and

wherein said RFID tag further includes a data gathering sensor cooperating with said memory.

14. The apparatus of claim 13 wherein said data gathering sensor is an environmental status sensor.

15. The apparatus of claim 14 wherein said environmental status sensor is a temperature sensor.

16. The apparatus of claim 13 wherein said plurality of interrogators include at least one choke point interrogator,

wherein said at least one choke point interrogator interrogates for ID'"'"'s of said RFID tag by means of time division multiplexing,

and wherein frame sizes within said time division multiplexing are adjusted by an interrogator processor calculating, so as to optimize said frame sizes by an optimizing frame size adjustment of said frame sizes according to, a collision rate between responses from said RFID tag in response to said interrogation from said choke point interrogator and responses from other RFID tags within a choke point communication range of said choke point interrogator.

17. The apparatus of claim 16 wherein said collision rate is determined by said choke point interrogator by said interrogator processor comparing:

(a) a cumulative first time period within said frame sizes wherein a signal strength detected by said choke point interrogator is increased so as to indicate transmission of responses from said RFID tag or said other RFID tags, with

(b) a cumulative second time period within said frame sizes corresponding to known valid responses received by said choke point interrogator from said RFID tag or said other RFID tags.

18. The apparatus of claim 17 wherein said interrogator processor calculates said optimizing frame size adjustment by increasing a total cumulative time within said frame sizes if said collision rate is higher than an optimal collision rate, and by decreasing said total cumulative time within said frame sizes if said collision rate is lower than said optimal collision rate.

19. The apparatus of claim 18 wherein said choke point interrogator interrogates said RFD tag and said other RFID tags within said choke point interrogator communication range in a rollcall until a statistical confidence level is obtained as determined by said choke point interrogator processor calculating a confidence level and said confidence level indicating that said RFID tag and said other RFD tags have all successfully been identified.

20. The apparatus of claim 13 wherein said each interrogator communicates said unique data to a central data base,

a central database processor cooperating with said central database and communicating with said plurality of interrogators so as to obtain up-to-date data, including said unique data, from said RFID tag as said RFID tag progresses along said distribution path,

distributed processors along said distribution path also in communication with said central database processor so that said distributed processors may obtain feedback information and data from said central database no matter where said RFID tag is along said distribution path so as to obtain up-to-date product status data from said up-to-date data including said unique data.

21. The apparatus of claim 20 wherein said distributed processors spaced along said distribution path and said plurality of interrogators are located at corresponding producer, shipment, warehousing, and retailing locations.

22. The apparatus of claim 20 wherein said communication with said central database processor is via the internet.

23. The apparatus of claim 18 wherein said optimal collision rate is in the range between 20–

30%.

24. The apparatus of claim 18 wherein said optimal collision rate is in the range between 10–

40%.