Extensible object location system and method using multiple references

• US 10,139,472 B2
• Filed: 05/05/2016
• Issued: 11/27/2018
• Est. Priority Date: 05/10/2005
• Status: Active Grant

• Current Assignee: Zebra Technologies Corporation
• Original Assignee: ZIH Corp. (Zebra Technologies Corporation)
• Inventors: Ameti, Aitan, Chen, Keming, Fontana, Robert J., Richley, Edward A., Turner, Belinda
• Primary Examiner(s): Gregory, Bernarr E
• Assistant Examiner(s): Mull, Fred H
• Application Number:
  US15/147,149
• Publication Number:
  US 20160245897A1
• Time in Patent Office: 936 Days
• Field of Search: 34053913, 3405733, 3405734, 119721
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/02213 Receivers arranged in a network for determining the position of a transmitter
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308

Abstract

An example disclosed method includes defining a first zone within a monitored area, a first group of receivers covering the first zone; defining a second zone within the monitored area, a second group of receivers covering the second zone; determining, via a processor, a first position of a first tag based on timing measurements obtained via the first group of receivers; determining, via the processor, whether the first position indicates that the first tag is within the first zone; and when the first position indicates that the first tag is not within the first zone, not reporting data associated with the first tag.

Claims

1. A method comprising:

defining a first zone within a monitored area, a first group of receivers covering the first zone;

defining a second zone within the monitored area, a second group of receivers covering the second zone;

determining, via a processor, (i) a first position of a first tag based on a first set of timing measurements obtained via the first group of receivers, and (ii) a second position of the first tag based on a second set of timing measurements obtained via the second group of receivers;

determining, via the processor, whether the first position indicates that the first tag is within the first zone;

when the first position indicates that the first tag is within the first zone, reporting data associated with the first tag; and

when the first position indicates that the first tag is not within the first zone, discarding the first position.

2. A method as defined in claim 1, wherein the data associated with the first tag includes at least one of personnel information, transmitter identifier, packet number, or a material description.

3. A method as defined in claim 1, wherein reporting the data associated with the first tag comprises transmitting the data associated with the first tag.

4. A method as defined in claim 1, wherein defining the first and second zones is based on a location of a radio frequency barrier in the monitored area.

5. A method as defined in claim 1, further comprising:

determining whether the second position indicates that the first tag is within the second zone;

when the second position indicates that the first tag is not within the second zone, discarding the second position; and

when the second position indicates that the first tag is within the second zone, reporting the data associated with the first tag.

6. A method as defined in claim 1, wherein each tag within the first zone has a direct line-of-sight path to each of the first group of receivers, and each tag within the second zone has a direct line-of-sight path to each of the second group of receivers.

7. A method as defined in claim 1, wherein defining the first zone includes establishing a first virtual boundary within the monitored area.

8. A system comprising:

a first group of receivers assigned to a first zone within a monitored area;

a second group of receivers assigned to a second zone within the monitored area;

a processor configured to;

determine (i) a first position for a first tag based on a first set of timing measurements obtained via the first group of receivers, and (ii) a second position of the first tag based on a second set of timing measurements obtained via the second group of receivers;

report data associated with the first tag when the first position is in the first zone; and

discard the first position when the first position is in the second zone.

9. A system as defined in claim 8, wherein the processor is to discard the second position when the second position is in the first zone.

10. A system as defined in claim 9, wherein the processor is to report data associated with the first tag when the second position is in the second zone.

11. A system as defined in claim 8, wherein the first group of receivers is assigned to the first zone and the second group of receivers is assigned to the second zone based on a location of a radio frequency barrier in the monitored area.

12. A system as defined in claim 8, wherein each tag within the first zone has a direct line-of-sight path to each of the first group of receivers, and each tag within the second zone has a direct line-of-sight path to each of the second group of receivers.

13. A system as defined in claim 8, wherein the first zone is defined by a first virtual boundary in the monitored area.

14. An apparatus, comprising:

memory comprising machine readable instructions; and

a processor configured to execute the machine readable instruction to perform operations including;

determining (i) a first position of a first tag based on timing measurements obtained via a first group of receivers assigned to a first zone defined in a monitored area, and (ii) a second position of the first tag based on a second set of timing measurements obtained via a second group of receivers assigned to a second zone defined in the monitored area; and

reporting information based on the first tag in association with the first position only when the first position is within the first zone.

15. An apparatus as defined in claim 14, wherein the operations include reporting information based on the first tag in association with the second position only when the second position is within the second zone.

16. An apparatus as defined in claim 14, wherein the first and second zones are defined based on a radio frequency barrier located in the monitored area.

17. An apparatus as defined in claim 14, wherein each tag within the first zone has a direct line-of-sight path to each of the first group of receivers, and each tag within the second zone has a direct line-of-sight path to each of the second group of receivers.

18. A method comprising:

defining a first zone within a monitored area, a first group of receivers covering the first zone;

defining a second zone within the monitored area, a second group of receivers covering the second zone;

determining, via a processor, (i) a first position of a first tag based on a first set of timing measurements obtained via the first group of receivers, and (ii) a second position of the first tag based on a second set of timing measurements obtained via the second group of receivers;

determining, via the processor, whether the first position indicates that the first tag is within the first zone;

when the first position indicates that the first tag is not within the first zone, discarding the first position;

determining, via the processor, whether the second position indicates that the first tag is within the second zone;

when the second position indicates that the first tag is not within the second zone, discarding the second position; and

when the second position indicates that the first tag is within the second zone, reporting the data associated with the first tag.

19. A system comprising:

a first group of receivers assigned to a first zone within a monitored area;

a second group of receivers assigned to a second zone within the monitored area;

a processor configured to;

determine (i) a first position for a first tag based on a first set of timing measurements obtained via the first group of receivers, and (ii) a second position of the first tag based on a second set of timing measurements obtained via the second group of receivers;

discard the first position when the first position is in the second zone;

discard the second position when the second position is in the first zone;

report data associated with the first tag when the first position is in the first zone; and

report the data associated with the first tag when the second position is in the second zone.