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

• US 20090027203A1
• Filed: 07/27/2007
• 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 7,898,419 B2
• Time in Patent Office: Days
• US Class Current: 340/572.100
• CPC Class Codes: G01S 13/876 Combination of several spaced transponders or reflectors of known location for determining the position of a receiver G01S13/874 takes precedence
• CPC Class Codes: G01S 5/0278 involving statistical or probabilistic considerations G01S5/0252, G01S5/0294 take precedence
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications
• CPC Class Codes: H04B 5/77 for interrogation

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 networked radio frequency identification system comprising:

a plurality of radio frequency identification (RFID) tag readers;

a computer in signal communication with the plurality of 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 between the endpoints,

wherein the endpoints are associated with physical locations in space.

2. The system of claim 1, wherein the software module is configured to determine a semantic attribute of RFID tag movement.

3. The system of claim 2, where the semantic attribute is selected from movement into or out of a previously defined area.

4. The system of claim 1, wherein the software module is configured to apply access control rules associated with the RFID tags.

5. A networked radio frequency identification system comprising:

a plurality of radio frequency identification (RFID) tag readers, wherein at least one of the RFID tag readers includes at least one adjustable configuration setting selected from RF signal strength, antenna gain, antenna polarization, and antenna orientation;

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

a software module for storage on and operable by the computer that is configured to localize RFID tags based on information received from the RFID tag readers and that is configured to adjust the at least one adjustable configuration setting based on at least one of input from a user or a previously saved system configuration setting.

6. The system of claim 5, wherein the software module is configured to accept time intervals from a user along with security levels that are associated with the time intervals and wherein the software module adjusts the at least one configuration setting based on the time intervals and their associated security levels.

7. The system of claim 6, wherein the adjusted configuration settings include RF signal strength.

8. A networked radio frequency identification system for localizing an RFID tag at an endpoint represented as E_i comprising:

a plurality of radio frequency identification (RFID) tag readers, each RFID tag reader including at least one adjustable setting selected from RF signal strength, antenna gain, antenna polarization, and antenna orientation, and each RFID tag reader including a radio frequency (RF) interrogator;

a computer in signal communication with the plurality of 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 hierarchical threshold limit calculations.

9. The system of claim 8, wherein the hierarchical threshold limit calculations are based on accumulated reading factors from groups of settings for the RFID tag readers.

10. The system of claim 9, wherein the software module is configured to:

collect data for each setting of the RFID tag readers during an interval of time;

calculate an aggregate result for each RFID tag reader based on an algorithm that uses a weighting function that includes W_k,l and NR_k,l as parameters where NR_k,l represents the number of RFID tag readings at an interrogator ‘

k’

configured with a setting ‘

l’ and

W_k,l represents a weighting factor assigned to the interrogator ‘

k’

configured with the setting ‘

l’

, and the algorithm spans all settings ‘

l’

for the interrogator ‘

k’

;

aggregate the calculated aggregate results based on a second weighting function to determine an aggregation result for an endpoint; and

compare the aggregation result for the endpoint to at least one of a threshold value or threshold interval to determine whether the RFID tag is localized at the endpoint.

11. The system of claim 8, wherein groups of the RFID tag readers are configurable to have a group setting and wherein the hierarchical threshold limit calculations are based on accumulated reading factors from settings of groups of RFID tag readers.

12. The system of claim 11, wherein the software module is configured to:

collect data for each group setting of a group of RFID tag readers during an interval of time;

calculate an aggregate result for each group setting based on an algorithm that uses a weighting function that includes W_k,l and NR_k,l as parameters where NR_k,l represents the number of RFID tag readings at an interrogator ‘

k’

configured with a group setting ‘

l’ and

W_k,l represents a weighting factor assigned to the interrogator ‘

k’

configured with the group setting ‘

l’

, and the algorithm spans all group settings ‘

l’

for the interrogator ‘

k’

;

aggregate the calculated aggregate results based on a second weighting function to determine an aggregation result for an endpoint; and

compare the aggregation result for the endpoint to at least one of a threshold value or threshold interval to determine whether the RFID tag is localized at the endpoint.

13. A networked radio frequency identification system for localizing an RFID tag at an endpoint represented as E_i comprising:

a plurality of radio frequency identification (RFID) tag readers, each RFID tag reader including at least one adjustable setting selected from RF signal strength, antenna gain, antenna polarization, and antenna orientation, and each RFID tag reader including a radio frequency (RF) interrogator;

a computer in signal communication with the plurality of 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 probabilistic threshold calculations.

14. The system of claim 13, wherein the probabilistic threshold calculations are based on accumulated probabilities from groups of settings for RFID tag readers.

15. The system of claim 14, wherein the software module is configured to:

collect data for each setting of the RFID tag readers during an interval of time;

calculate an aggregate result for each RFID tag reader based on an algorithm that uses a weighting function that includes W_k,l and P_k,l as parameters where P_k,l=PF_k,l(NR_k,l, C_k,l) is the probability that the RFID tag is at endpoint E_i as detected from interrogator ‘

k’

with settings ‘

l’

calculated with the function PF_k,l with NR_k,l representing the number of RFID tag readings at interrogator ‘

k’

configured with settings ‘

l’ and

C_k,l representing a reference reading value for interrogator ‘

k’

configured with settings ‘

l’ and

where W_k,l represents a weighting factor assigned to the interrogator ‘

k’

configured with the settings ‘

l’

, and the algorithm spans all settings ‘

l’

for the interrogator ‘

k’

;

aggregate the calculated aggregate results based on a second weighting function to determine an aggregation result for an endpoint; and

compare the aggregation result for the endpoint to at least one of a threshold value or threshold interval to determine whether the RFID tag is localized at the endpoint.

16. The system of claim 13, wherein groups of the RFID tag readers are configurable to have a group setting and wherein the probabilistic threshold calculations are based on accumulated probabilities from settings of groups of RFID tag readers.

17. The system of claim 16, wherein the software module is configured to:

collect data for each group setting of a group of RFID tag readers during an interval of time;

calculate an aggregate result for each group setting based on an algorithm that uses a weighting function that includes Wk,l and Pk,l as parameters where P_k,l=PF_k,l(NR_k,l, C_k,l) is the probability that the RFID tag is at endpoint E_i as detected from interrogator ‘

k’

with group settings ‘

l’

calculated with the function PF_k,l with NR_k,l representing the number of RFID tag readings at interrogator ‘

k’

configured with group settings ‘

l’ and

C_k,l representing a reference reading value for interrogator ‘

k’

configured with group settings ‘

l’ and

where W_k,l represents a weighting factor assigned to the interrogator ‘

k’

configured with the group settings ‘

l’

, and the algorithm spans all group settings ‘

l’

for the interrogator ‘

k’

;

aggregate the calculated aggregate results based on a second weighting function to determine an aggregation result for an endpoint; and

compare the aggregation result for the endpoint to at least one of a threshold value or threshold interval to determine whether the RFID tag is localized at the endpoint.

18. A networked radio frequency identification system comprising:

a plurality of radio frequency identification (RFID) tag readers;

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

a locking device associated with an access point, the locking device in signal communication with the computer;

an input device in signal communication with the computer; and

a software module for storage on and operable by the computer that localizes an authorized RFID tag at the access point based on information received from at least one of the plurality of RFID tag readers, receives additional authorizing information from the input device, and sends an unlock signal to the locking device based on the localization of the authorized RFID tag at the access point and the additional authorizing information.

19. The system of claim 18, wherein the input device is a keypad and the additional authorizing information is an access code.

20. The system of claim 18, wherein the input device includes a mobile communications device, the software module is configured to send a request for an access code to the mobile communications device after the authorized RFID tag is localized at the access point, and the additional authorizing information is the requested access code transmitted from the mobile communications device.

21. A networked radio frequency identification system comprising:

a plurality of radio frequency identification (RFID) tag readers;

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

a locking device associated with an access point, the locking device in signal communication with the computer;

a location enabled mobile device that generates location information identifying the position of the mobile device, the mobile device in signal communication with the computer; and

a software module for storage on and operable by the computer that receives the location information from the location enabled mobile device, localizes an authorized RFID tag at the access point based on information received from at least one of the plurality of RFID tag readers, and sends an unlock signal to the locking device based on the localization of the authorized RFID tag at the access point and the location information from the location enabled mobile device.

22. The system of claim 21, wherein the location enabled mobile device includes a global positioning system (GPS) device that generates GPS coordinates, the software module is configured to receive the GPS coordinates from the mobile device when the authorized RFID tag is localized at the access point, and the unlock signal is sent based on a comparison between the GPS coordinate location reported by the mobile device and the location of the RFID tag at the access point.

23. A method of determining a semantic attribute of movement using a system that includes a plurality of radio frequency identification (RFID) tag readers, a computer in signal communication with the plurality of RFID tag readers over a network, and a software module for storage on and operable by the computer, the method comprising:

mapping a first endpoint in a network model to a first physical location;

mapping a second endpoint in the network model to a second physical location;

determining that an RFID tag is present at the first endpoint based on information from a first RFID tag reader at a first time value;

determining that the RFID tag is present at the second endpoint based on information from a second RFID tag reader at a second time value;

determining an oriented link based on the determined presence of the RFID tag at the first endpoint and the second endpoint; and

determining a semantic attribute of movement based on the oriented link.

24. A method of localizing an RFID tag using a system that includes a plurality of radio frequency identification (RFID) tag readers at least one of which includes an adjustable RF signal strength configuration setting, a computer in signal communication with the plurality of RFID tag readers over a network, and a software module for storage on and operable by the computer, the method comprising:

receiving a time interval and an associated security level setting from a user at the computer;

adjusting the RF signal strength setting on at least one of the RFID tag readers based on the received time interval and associated security level setting; and

determining that the RFID tag is present at a first endpoint based on information from at least one of the RFID tag readers having an adjusted RF signal strength setting.

25. A method of localizing an RFID tag using a system that includes a plurality of radio frequency identification (RFID) tag readers each of which includes at least one adjustable configuration setting selected from RF signal strength, antenna gain, antenna polarization, and antenna orientation, a computer in signal communication with the plurality of RFID tag readers over a network, and a software module for storage on and operable by the computer, the method comprising:

collecting data for each setting of the RFID tag readers during an interval of time;

calculating an aggregate result for each RFID tag reader based on an algorithm that uses a weighting function that includes W_k,l and NR_k,l as parameters where NR_k,l represents the number of RFID tag readings at an interrogator ‘

k’

configured with a setting ‘

l’ and

W_k,l represents a weighting factor assigned to the interrogator ‘

k’

configured with the setting ‘

l’

, and the algorithm spans all settings ‘

l’

for the interrogator ‘

k’

;

aggregating the calculated aggregate results based on a second weighting function to determine an aggregation result for an endpoint; and

comparing the aggregation result for the endpoint to at least one of a threshold value or threshold interval to determine whether the RFID tag is localized at the endpoint.

26. A method of localizing an RFID tag using a system that includes a plurality of radio frequency identification (RFID) tag readers which include at least one adjustable group configuration setting selected from RF signal strength, antenna gain, antenna polarization, and antenna orientation, a computer in signal communication with the plurality of RFID tag readers over a network, and a software module for storage on and operable by the computer, the method comprising:

collecting data for each group setting of a group of RFID tag readers during an interval of time;

calculating an aggregate result for each group setting based on an algorithm that uses a weighting function that includes W_k,l and P_k,l as parameters where P_k,l=PF_k,l(NR_k,l, C_k,l) is the probability that the RFID tag is at endpoint E_i as detected from interrogator ‘

k’

with group settings ‘

l’

calculated with the function PF_k,l with NR_k,l representing the number of RFID tag readings at interrogator ‘

k’

configured with group settings ‘

l’ and

C_k,l representing a reference reading value for interrogator ‘

k’

configured with group settings ‘

l’ and

where W_k,l represents a weighting factor assigned to the interrogator ‘

k’

configured with the group settings ‘

l’

, and the algorithm spans all group settings ‘

l’

for the interrogator ‘

k’

;

aggregating the calculated aggregate results based on a second weighting function to determine an aggregation result for an endpoint; and

comparing the aggregation result for the endpoint to at least one of a threshold value or threshold interval to determine whether the RFID tag is localized at the endpoint.

27. A method of unlocking an access point using a radio frequency identification (RFID) tag system that includes a plurality of RFID tag readers, a computer in signal communication with the plurality of RFID tag readers over a network, a locking device in signal communication with the computer and associated with an access point, an input device in signal communication with the computer, and a software module for storage on and operable by the computer, the method comprising:

determining an authorized RFID tag is present at an access point based on information received from at least one of the RFID tag readers;

receiving an access code as additional authorizing information at the input device; and

unlocking the locking device based on the determined location of the RFID tag and the received access code.

28. A method of localizing an RFID tag using a system that includes a plurality of radio frequency identification (RFID) tag readers which include at least one adjustable group configuration setting selected from RF signal strength, antenna gain, antenna polarization, and antenna orientation, a computer in signal communication with the plurality of RFID tag readers over a network, and a software module for storage on and operable by the computer, the method comprising:

collecting data for each group setting of a group of RFID tag readers during an interval of time;

calculating an aggregate result for each group setting based on an algorithm that uses a weighting function that includes W_k,l and NR_k,l as parameters where NR_k,l represents the number of RFID tag readings at an interrogator ‘

k’

configured with a group setting ‘

l’ and

W_k,l represents a weighting factor assigned to the interrogator ‘

k’

configured with the group setting ‘

l’

, and the algorithm spans all settings ‘

l’

for the interrogator ‘

k’

;

aggregating the calculated aggregate results based on a second weighting function to determine an aggregation result for an endpoint; and

comparing the aggregation result for the endpoint to at least one of a threshold value or threshold interval to determine whether the RFID tag is localized at the endpoint.

29. A method of localizing an RFID tag using a system that includes a plurality of radio frequency identification (RFID) tag readers each of which includes at least one adjustable configuration setting selected from RF signal strength, antenna gain, antenna polarization, and antenna orientation, a computer in signal communication with the plurality of RFID tag readers over a network, and a software module for storage on and operable by the computer, the method comprising:

collecting data for each setting of the RFID tag readers during an interval of time;

calculating an aggregate result for each RFID tag reader based on an algorithm that uses a weighting function that includes W_k,l and P_k,l as parameters where P_k,l=PF_k,l(NR_k,l, C_k,l) is the probability that the RFID tag is at endpoint E_i as detected from interrogator ‘

k’

with settings ‘

l’

calculated with the function PF_k,l with NR_k,l representing the number of RFID tag readings at interrogator ‘

k’

configured with settings ‘

l’ and

C_k,l representing a reference reading value for interrogator ‘

k’

configured with settings ‘

l’ and

where W_k,l represents a weighting factor assigned to the interrogator ‘

k’

configured with the settings ‘

l’

, and the algorithm spans all settings ‘

l’

for the interrogator ‘

k’

;

aggregating the calculated aggregate results based on a second weighting function to determine an aggregation result for an endpoint; and

comparing the aggregation result for the endpoint to at least one of a threshold value or threshold interval to determine whether the RFID tag is localized at the endpoint.