Systems and methods for object localization and path identification based on RFID sensing

• US 8,665,067 B2
• Filed: 12/21/2007
• Issued: 03/04/2014
• Est. Priority Date: 07/27/2007
• Status: Expired due to Fees

• Current Assignee: Lucomm Technologies, Inc.
• Original Assignee: Lucomm Technologies, Inc.
• Inventors: Cristache, Lucian
• Primary Examiner(s): Zimmerman, Brian
• Assistant Examiner(s): Khan, Omer S
• Application Number:
  US11/963,697
• Publication Number:
  US 20090027165A1
• Time in Patent Office: 2,265 Days
• Field of Search: 340/10.1, 340/10.2, 3405721-5724, 726/2
• US Class Current: 340/10.1
• 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 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;

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 validate or invalidate a reading by the RFID tag readers that the tag is present at the second endpoint at a second time, wherein the validation that the tag moved from the first endpoint to the second endpoint is only made by the software module when the difference between the first time and the second time is within a specified interval, whereby the software module invalidates a reading that the tag is present at the second endpoint despite if the difference between the first time and the second time is less than a lower end of the specified interval; and

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 the upper end of the specified interval.

2. 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.

3. The system of claim 2, wherein the specified cost for the links of a path between the first endpoint and the second endpoint is established dynamically.

4. The system of claim 2, 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.

5. The system of claim 2, wherein the specified cost for the links of a path between the first endpoint and the second endpoint is related to access control settings.

6. The system of claim 2, 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.