SYSTEMS AND METHODS FOR OBJECT LOCALIZATION AND PATH IDENTIFICATION BASED ON RFID SENSING

• US 20090027165A1
• Filed: 12/21/2007
• Published: 01/29/2009
• Est. Priority Date: 07/27/2007
• Status: Active Grant

• Current Assignee: Lucomm Technologies, Inc.
• Original Assignee: Lucomm Technologies, Inc.
• Inventors: Cristache, Lucian
• Granted Patent: US 8,665,067 B2
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: G01S 13/82 wherein continuous-type signals are transmitted
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence

Abstract

A networked radio frequency identification system includes a plurality of radio frequency identification (RFID) tag readers, a computer in signal communication with the RFID tag readers over a network, and a software module for storage on and operable by the computer that localizes RFID tags based on information received from the RFID tag readers using a network model having endpoints and oriented links. In an additional example, at least one of the RFID tag readers includes an adjustable configuration setting selected from RF signal strength, antenna gain, antenna polarization, and antenna orientation. In a further aspect, the system localizes RFID tags based on hierarchical threshold limit calculations. In an additional aspect, the system controls a locking device associated with an access point based on localization of an authorized RFID tag at the access point and reception of additional authorizing information from an input device.

Claims

1. A radio frequency identification system comprising:

a plurality location-based endpoints, each of the endpoints having associated with it a plurality of radio frequency identification (RFID) tag readers;

a computer in signal communication with the plurality of RFID tag readers;

a memory associated with the computer, the memory storing data indicating that an RFID tag has been read by one or more of the RFID tag readers; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to determine that the tag is present at a first one of the plurality of endpoints when the computer determines that the tag has been read by a specified number of RFID tag readers from among the plurality of RFID tag readers associated with the first one of the plurality of endpoints, and further wherein each of the specified number of RFID tag readers is determined to have read the tag within a specified time.

2. The system of claim 1, wherein the specified number of tag readers is two and the specified time is 1 second.

3. A radio frequency identification system comprising:

a first location-based endpoint and a second location-based endpoint, each of the endpoints having associated with it one or more radio frequency identification (RFID) tag readers;

a computer in signal communication with the RFID tag readers;

a memory associated with the computer, the memory storing data indicating that an RFID tag has been read by the RFID tag readers;

an access control system between the first endpoint and the second endpoint, the access control system being under the control of the computer; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to determine that the tag is present at the first endpoint at a first point in time and further to deny access by the tag to the second endpoint via the access control system until the passage of a specified period of time after the tag was determined to be present at the first endpoint.

4. The system of claim 3, further comprising a first link defining a first path from the first endpoint to the second endpoint, and a second link defining a second path from the second endpoint to the first endpoint, wherein the software module causes the access control system to deny access by the tag via the first path for the specified period of time after the tag was determined to be present at the first endpoint via the second path.

5. A radio frequency identification system comprising:

a first location-based endpoint and a second location-based endpoint, each of the endpoints having associated with it one or more radio frequency identification (RFID) tag readers;

a computer in signal communication with the RFID tag readers;

a memory associated with the computer, the memory storing data indicating that an RFID tag has been read by the RFID tag readers; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to determine that the tag is present at the first endpoint at a first time and to determine that the tag is present at the second endpoint at a second time when the tag readers detect the presence of the tag at the second endpoint, wherein the determination that the tag moved from the first endpoint to the second endpoint is only made when the difference between the first time and the second time is within a specified interval.

6. The system of claim 5, further comprising a first link defining a first path from the first endpoint to the second endpoint, wherein the software module determines that the tag has traversed the first link when the difference between the second time and the first time is less than a specified interval.

7. A radio frequency identification system comprising:

a plurality location-based endpoints, each of the endpoints having associated with it one or more radio frequency identification (RFID) tag readers;

a computer in signal communication with the plurality of RFID tag readers;

a memory associated with the computer, the memory storing data indicating that an RFID tag has been read by one or more of the RFID tag readers; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to determine that the tag is present at one of the plurality of endpoints, and further to treat as invalid all previously stored data indicating that the tag has been read by tag readers for endpoints beyond a specified range from the endpoint at which the tag is determined to be present.

8. The system of claim 7, wherein the software module treats tag readings as invalid by deleting the tag readings from the memory.

9. The system of claim 7, wherein the software module treats tag readings as invalid by adding an invalid indication to the data stored in the memory.

10. A radio frequency identification system comprising:

a plurality location-based endpoints, each of the endpoints having associated with it one or more radio frequency identification (RFID) tag readers, each of the endpoints further having one or more links defining paths of travel between endpoints, each of the links having a specified cost for a tag to traverse the link;

a computer in signal communication with the plurality of RFID tag readers;

a memory associated with the computer, the memory storing data indicating that the RFID tag has been read by one or more of the RFID tag readers; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to determine that the tag is present at a first one of the plurality of endpoints, and further to treat as invalid previously stored data indicating that the tag has been read by tag readers at a second one of the plurality of endpoints if a specified cost for a path between the first endpoint and the second endpoint exceeds a specified cost threshold.

11. The system of claim 10, wherein the specified cost for the links of a path between the first endpoint and the second endpoint is established dynamically.

12. The system of claim 10, wherein the specified cost for the links of a path between the first endpoint and the second endpoint is based on historical data related to the movement of the tag.

13. The system of claim 10, wherein the specified cost for the links of a path between the first endpoint and the second endpoint is related to access control settings.

14. The system of claim 10, wherein the specified cost for the path between the first endpoint and the second endpoint is a function of a number of links between the first endpoint and the second endpoint.

15. A radio frequency identification system comprising:

a plurality location-based endpoints, each of the endpoints having associated with it one or more radio frequency identification (RFID) tag readers, each of the endpoints further having one or more links defining paths of travel between endpoints;

a computer in signal communication with the plurality of RFID tag readers;

a memory associated with the computer, the memory storing data indicating that the RFID tag has been read by one or more of the RFID tag readers; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to determine that the tag is present at a first one of the plurality of endpoints, and further to treat as invalid previously stored data indicating that the tag has been read by tag readers at a second one of the plurality of endpoints if there is no path between the first endpoint and the second endpoint.

16. A radio frequency identification system comprising:

a first location-based endpoint and a second location-based endpoint, each of the endpoints having associated with it one or more radio frequency identification (RFID) tag readers, each of the endpoints further having one or more links defining paths of travel between endpoints;

a computer in signal communication with the RFID tag readers;

a memory associated with the computer, the memory storing data indicating that an RFID tag has been read by the RFID tag readers; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to determine that the tag is present at the first endpoint at a first time and to determine that the tag is localized at the second endpoint at a second time upon detection by one or more of the tag readers of the presence of the tag at the second endpoint, wherein the determination that the tag is present at the second endpoint is only made when there is a defined link from the first endpoint to the second endpoint.

17. A radio frequency identification system comprising:

a plurality location-based endpoints, each of the endpoints having associated with it one or more radio frequency identification (RFID) antennas, each of the endpoints further having one or more links defining paths of travel between the endpoints, wherein the plurality of endpoints includes at least a first endpoint and a second endpoint having a first link between the first endpoint and the second endpoint;

a computer in signal communication with the plurality of RFID tag readers; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to determine that the tag is present at the first endpoint, the software module further activating the antennas associated with the second endpoint when the tag is determined to be present at the first endpoint.

18. The system of claim 18, further comprising one or more additional endpoints connected via one or more additional links to the first endpoint, and wherein the software module further activates antennas associated with the one or more additional endpoints when the tag is determined to be present at the first endpoint.

19. A radio frequency identification system comprising:

a plurality location-based endpoints, each of the endpoints having associated with it one or more radio frequency identification (RFID) antennas, each of the endpoints further having one or more links defining paths of travel between the endpoints, each of the paths having a defined cost, wherein the plurality of endpoints includes at least a first endpoint and one or more additional endpoints connected to the first endpoint via one or more additional paths of travel;

a computer in signal communication with the plurality of RFID tag readers; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to determine that the tag is present at the first endpoint, and further, when the tag is determined to be present at the first endpoint, the software module further activating those antennas associated with endpoints from among the one or more additional endpoints that have paths with defined costs that are less than a specified cost threshold.

20. A radio frequency identification system comprising:

a plurality location-based endpoints, each of the endpoints having associated with it one or more radio frequency identification (RFID) antennas, each of the endpoints further having one or more links defining paths of travel between the endpoints, each of the paths having a defined cost, wherein the plurality of endpoints includes at least a first endpoint and one or more additional endpoints connected to the first endpoint via one or more additional paths of travel;

a computer in signal communication with the plurality of RFID tag readers; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to determine that the tag is present at the first endpoint, and further, when the tag is determined to be present at the first endpoint, the software module further deactivating those antennas associated with endpoints from among the one or more additional endpoints that have paths with defined costs that are greater than a specified cost threshold.

21. A radio frequency identification system comprising:

a plurality location-based endpoints, each of the endpoints having associated with it one or more radio frequency identification (RFID) antennas, each of the endpoints further having one or more links defining paths of travel between the endpoints, wherein the plurality of endpoints includes at least a first endpoint and a second endpoint having a first link between the first endpoint and the second endpoint, the plurality of endpoints further including a third endpoint, the third endpoint not having a link to the first endpoint;

a computer in signal communication with the plurality of RFID tag readers; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to determine that the tag is present at the first endpoint, the software module further deactivating the antennas associated with the third endpoint when the tag is determined to be present at the first endpoint.

22. A radio frequency identification system comprising:

a plurality location-based endpoints, each of the endpoints having associated with it a plurality of radio frequency identification (RFID) tag readers;

a computer in signal communication with the plurality of RFID tag readers;

a memory associated with the computer, the memory storing data indicating that one or more of a plurality of RFID tags has been read by one or more of the RFID tag readers; and

a software module for storage on and operable by the computer, the software module including programming instructions causing the computer to (1) determine that one or more tags is present at a first one of the plurality of endpoints based on signals received from the tag readers, (2) cause the memory to store a database associating the one or more tags with one or more of the plurality of endpoints at which the one or more tags is determined to be present, and (3) update the database upon determination by the module that the one or more tags is no longer present at the first endpoint.

23. The system of claim 22, wherein the software module further determines a first time at which a first one of the tags is determined to be present at the first endpoint and stores the first time in the memory, and further updates the database to remove the first tag from the database associating the first tag with the first endpoint when the first tag is not determined to be at any one of the other endpoints from among the plurality of endpoints within a defined time after the first time.