METHOD AND A SYSTEM FOR DETERMINING THE LOCATION OF A SUBJECT, AND A RADIO FREQUENCY IDENTIFICATION TAG ASSEMBLY

• US 20110148602A1
• Filed: 07/23/2008
• Published: 06/23/2011
• Est. Priority Date: 07/23/2008
• Status: Active Grant

• Current Assignee: CADI Scientific Pte Ltd.
• Original Assignee: CADI Scientific Pte Ltd.
• Inventors: Goh, Zenton, Neo, Sian Sheng, Lim, Soh Min, NG, Hon Cheong
• Granted Patent: US 8,610,545 B2
• Time in Patent Office: Days
• US Class Current: 340/10.41
• CPC Class Codes: G01S 2013/466 by Trilateration, i.e. two antennas or two sensors determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the antennas or sensors, the position data of the target is determined
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs

Abstract

According to one embodiment of the present invention, a method for determining the location of a subject is provided. The method includes receiving, by a first set of receivers out of a plurality of receivers, a first signal from a radio frequency identification tag being assigned to the subject, wherein the radio frequency identification tag has assigned a radio frequency identification tag identity; receiving, by a second set of receivers out of a plurality of receivers, a second signal from the radio frequency identification tag, the second signal being different from the first signal, wherein the second set of receivers is different from the first set of receivers; computing a location score based on an information about the first signal, wherein the information about the first signal is included in the first signal and on the first set of receivers, and further based on an information about the second signal, wherein the information about the second signal is included in the second signal and on the second set of receivers; and determining the location of the subject based on the location score. A system for determining the location of a subject is also provided. A radio frequency identification tag assembly is also provided.

Claims

1. A method for determining the location of a subject, comprising:

receiving, by a first set of receivers out of a plurality of receivers, a first signal from a radio frequency identification tag being assigned to the subject, wherein the radio frequency identification tag has assigned a radio frequency identification tag identity;

receiving, by a second set of receivers out of a plurality of receivers, a second signal from the radio frequency identification tag, the second signal being different from the first signal, wherein the second set of receivers is different from the first set of receivers;

computing a location score based on an information about the first signal, wherein the information about the first signal is included in the first signal and on the first set of receivers, and further based on an information about the second signal, wherein the information about the second signal is included in the second signal and on the second set of receivers; and

determining the location of the subject based on the location score.

2. The method according to claim 1, wherein

determining the location of the subject based on the location score comprises determining if the location score is unique.

3. The method according to claim 2, further comprising

checking a location history of the radio frequency identification tag if there is no unique location score.

4. The method according to claim 1, further comprising

receiving, by the first set of receivers out of a plurality of receivers, the second signal from the radio frequency identification tag.

5. The method according to claim 1, further comprising

receiving, by the second set of receivers out of a plurality of receivers, the first signal from the radio frequency identification tag.

6. The method according to claim 1, wherein

each of the first set of receivers includes a first interrogation zone and each of the second set of receivers includes a second interrogation zone.

7. The method according to claim 6, wherein

the first interrogation zone is smaller than the second interrogation zone.

8. The method according to claim 1, further comprising

collecting the first signal and/or the second signal received by the second set of receivers in a controller server within a pre-defined time interval.

9. The method according to claim 8, further comprising

storing the received signal in a database server.

10. The method according to claim 9, further comprising

processing the stored signal in an application server and saving the processed signal in the database server.

11. The method according to claim 1, further comprising

associating each location with a predetermined set of receivers out of a plurality of receivers.

12. The method according to claim 1, wherein

computing a location score includes computing a location score further based on a projected movement of the subject.

13. The method according to claim 12, wherein

the projected movement of the subject is dependent on at least one item selected from a group consisting of location history of the subject, direction of movement, speed of movement and layout of the location.

14. The method according to claim 1, wherein

the first signal includes a signal above a first predetermined threshold value.

15. The method according to claim 14, wherein

the second signal includes a signal below a second predetermined threshold value.

16. The method according to claim 15, wherein

the second predetermined threshold value is lower than the first predetermined threshold value.

17. The method according to claim 15, wherein

the second predetermined threshold value is at least substantially the same as the first predetermined threshold value.

18. A system for determining the location of a subject, comprising:

a first set of receivers out of a plurality of receivers for receiving a first signal from a radio frequency identification tag being assigned to the subject, wherein the radio frequency identification tag has assigned a radio frequency identification tag identity;

a second set of receivers out of a plurality of receivers for receiving a second signal from the radio frequency identification tag, the second signal being different from the first signal, wherein the second set of receivers is different from the first set of receivers;

a computing unit for computing a location score based on an information about the first signal, wherein the information about the first signal is included in the first signal and on the first set of receivers, and further based on an information about the second signal, wherein the information about the second signal is included in the second signal and on the second set of receivers; and

a determining unit for determining the location of the subject based on the location score.

19. The system according to claim 18, wherein

the determining unit being further configured to determine, if the location score is unique.

20. The system according to claim 19, further comprising

a checking unit for checking a location history of the radio frequency identification tag if there is no unique location score.

21. The system according to claim 18, wherein

the first set of receivers out of a plurality of receivers further receive the second signal from the radio frequency identification tag.

22. The system according to claim 18, wherein

the second set of receivers out of a plurality of receivers further receive the first signal from the radio frequency identification tag.

23. The system according to claim 18, wherein

each of the first set of receivers includes a first interrogation zone and each of the second set of receivers includes a second interrogation zone.

24. The system according to claim 23, wherein

the first interrogation zone is smaller than the second interrogation zone.

25. The system according to claim 18, further comprising

a controller server connected to the second set of receivers, the controller server collecting the first signal and/or the second signal received by the second set of receivers within a pre-defined time interval.

26. The system according to claim 25, further comprising

a database server connected to the controller server, the database server storing the received signal.

27. The system according to claim 26, further comprising

an application server connected to the database server, the application server processing the stored signal.

28. The system according to claim 18, further comprising

an associating unit for associating each location with a predetermined set of receivers out of a plurality of receivers.

29. The system according to claim 18, wherein

the computing unit being further configured to compute a location score further based on a projected movement of the subject.

30. The system according to claim 29, wherein

the projected movement of the subject is dependent on at least one item selected from a group consisting of location history of the subject, direction of movement, speed of movement and layout of the location.

31. The system according to claim 18, wherein

the first signal includes a signal above a first predetermined threshold value.

32. The system according to claim 31, wherein

the second signal includes a signal below a second predetermined threshold value.

33. The system according to claim 32, wherein

the second predetermined threshold value is lower than the first predetermined threshold value.

34. The system according to claim 32, wherein

the second predetermined threshold value is at least substantially the same as the first predetermined threshold value.

35. The system according to claim 18, wherein

the first set of receivers is in communication with the second set of receivers via radio frequency means.

36. The system according to claim 18, wherein

the second set of receivers is in communication with the controller server via a communication network.

37. A radio frequency identification tag assembly comprising :

a first tag, the first tag having a first tag identity;

a second tag, the second tag having a second tag identity and a second tag memory portion;

wherein the first tag identity and the second tag identity are stored in the second tag memory portion of the second tag.

38. The radio frequency identification tag assembly according to claim 37,

wherein the first tag further comprising a first tag memory portion.

39. The radio frequency identification tag assembly according to claim 38,

wherein the first tag identity is stored in the first tag memory portion.

40. The radio frequency identification tag assembly according to claim 37,

wherein the first tag and the second tag are electrically isolated from each other.

41. The radio frequency identification tag assembly according to claim 37,

wherein the second tag memory portion of the second tag is a non-volatile memory.

42. The radio frequency identification tag assembly according to claim 38,

wherein the first tag memory portion of the first tag is a non-volatile memory.

43. The radio frequency identification tag assembly according to claim 37,

wherein the first tag is an active radio frequency identification tag and the second tag is a passive radio frequency identification tag.

44. The radio frequency identification tag assembly according to claim 37,

wherein the first tag is a passive radio frequency identification tag and the second tag is an active radio frequency identification tag.

45. The radio frequency identification tag assembly according to claim 43,

wherein the active radio frequency identification tag further comprises a thermistor.

46. The radio frequency identification tag assembly according to claim 43,

wherein the active radio frequency identification tag further comprises

a radio frequency identification circuit;

and

a normally closed switch connected to the radio frequency identification circuit, wherein the normally closed switch is configured such that when it is subjected to a magnetic field environment, the radio frequency identification circuit is electrically disconnected from a power supply and when it is out of the magnetic field environment, the radio frequency identification circuit is electrically connected to the power supply.

47. A radio frequency identification tag assembly comprising :

a radio frequency identification circuit;

a normally closed switch connected to the radio frequency identification circuit, wherein the normally closed switch is configured such that when it is subjected to a magnetic field environment, the radio frequency identification circuit is electrically disconnected from a power supply and when it is out of the magnetic field environment, the radio frequency identification circuit is electrically connected to the power supply.