Security tag positioning

Patent metadata

Field	Value
Publication number	US-2016180673-A1
Application number	US-201414575989-A
Country	US
Kind code	A1
Filing date	Dec 18, 2014
Priority date	Dec 18, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

A tag controller is configured to interface with a security tag adapted to be disposed on a corresponding product in a monitoring environment. The tag controller includes processing circuitry configured to perform a tag position estimation by receiving information indicative of signal strength measured at the security tag relative to each of a plurality of locating beacons disposed in the monitoring environment, defining an order of a selected number of the locating beacons based on signal strength, determining a first midpoint between two of the selected number of the locating beacons having the lowest signal strengths, determining at least a second midpoint between the first midpoint and a locating beacon having a next lowest signal strength, and determining a location of the security tag at least in part based on the second midpoint.

First claim

That which is claimed:

1 . A tag controller configured to interface with a security tag adapted to be disposed on a corresponding product in a monitoring environment, the tag controller comprising processing circuitry configured to perform a tag position estimation comprising:
receiving information indicative of signal strength measured at the security tag relative to each of a plurality of locating beacons disposed in the monitoring environment; defining an order of a selected number of the locating beacons based on signal strength; determining a first midpoint between two of the selected number of the locating beacons having the lowest signal strengths; determining at least a second midpoint between the first midpoint and a locating beacon having a next lowest signal strength; and determining a location of the security tag at least in part based on the second midpoint.

2 . The tag controller of claim 1 , wherein determining the location of the security tag comprises determining the location of the security tag as the second midpoint in response to the selected number of the locating beacons being three.

3 . The tag controller of claim 1 , wherein, in response to the selected number of the locating beacons being n, where n>3, determining the location of the security tag further comprises:
after determining the second midpoint, setting m=3 and performing a loop procedure, the loop procedure comprising determining a m th midpoint between the m−1 th midpoint and a locating beacon having a next lowest signal strength, if m<n−1, incrementing m by 1 and repeating the loop procedure until m=n−1, in response to m=n−1, determining the location of the security tag as the n−1 th midpoint.

4 . The tag controller of claim 1 , wherein the processing circuitry is further configured to:
repeat the tag position estimation at least x number of times; store x most recent determined locations of the security tag comprises; and determine an average tag position as an average of the x most recent determined locations.

5 . The tag controller of claim 1 , wherein defining the order further comprises weighting each locating beacon according to a ratio of signal strength and time received.

6 . The tag controller of claim 5 , wherein the processing circuitry is further configured to perform floor disambiguation in response to a determination that the security tag is being simultaneously tracked on more than one floor.

7 . The tag controller of claim 6 , wherein the floor disambiguation comprises comparing weights of locating beacons and differentiating between floors based on a floor having a highest locating beacon weight.

8 . The tag controller of claim 1 , wherein the signal strength is RSSI.

9 . A security system comprising:
at least one security tag disposed on a product in a monitoring environment; a plurality of locating beacons associated with a locating system for tracking the security tag in the monitoring environment; and a tag controller comprising processing circuitry configured to perform a tag position estimation comprising:
receiving information indicative of signal strength measured at the security tag relative to each of a plurality of locating beacons disposed in the monitoring environment;
defining an order of a selected number of the locating beacons based on signal strength;
determining a first midpoint between two of the selected number of the locating beacons having the lowest signal strengths;
determining at least a second midpoint between the first midpoint and a locating beacon having a next lowest signal strength; and
determining a location of the security tag at least in part based on the second midpoint.

10 . The security system of claim 9 , wherein determining the location of the security tag comprises determining the location of the security tag as the second midpoint in response to the selected number of the locating beacons being three.

11 . The security system of claim 9 , wherein, in response to the selected number of the locating beacons being n, where n>3, determining the location of the security tag comprises:
after determining the second midpoint, setting m=3 and performing a loop procedure, the loop procedure comprising determining a m th midpoint between the m−1 th midpoint and a locating beacon having a next lowest signal strength, if m<n−1, incrementing m by 1 and repeating the loop procedure until m=n−1, in response to m=n−1, determining the location of the security tag as the n−1 th midpoint.

12 . The security system of claim 9 , wherein the processing circuitry is further configured to:
repeat the tag position estimation at least x number of times; store x most recent determined locations of the security tag comprises; and determine an average tag position as an average of the x most recent determined locations.

13 . The security system of claim 9 , wherein defining the order further comprises weighting each locating beacon according to a ratio of signal strength and time received.

14 . The security system of claim 13 , wherein the processing circuitry is further configured to perform floor disambiguation in response to a determination that the security tag is being simultaneously tracked on more than one floor.

15 . The security system of claim 14 , wherein the floor disambiguation comprises comparing weights of locating beacons and differentiating between floors based on a floor having a highest locating beacon weight.

16 . The security system of claim 9 , wherein the signal strength is RSSI.

17 . A method of performing tag position estimation for a security tag adapted to be disposed on a corresponding product in a monitoring environment, method comprising:
receiving information indicative of signal strength measured at the security tag relative to each of a plurality of locating beacons disposed in the monitoring environment; defining an order of a selected number of the locating beacons based on signal strength; determining a first midpoint between two of the selected number of the locating beacons having the lowest signal strengths; determining at least a second midpoint between the first midpoint and a locating beacon having a next lowest signal strength; and determining a location of the security tag at least in part based on the second midpoint.

18 . The method of claim 17 , wherein determining the location of the security tag comprises determining the location of the security tag as the second midpoint in response to the selected number of the locating beacons being three.

19 . The method of claim 17 , wherein, in response to the selected number of the locating beacons being n, where n>3, determining the location of the security tag comprises:
after determining the second midpoint, setting m=3 and performing a loop procedure, the loop procedure comprising determining a m th midpoint between the m−1 th midpoint and a locating beacon having a next lowest signal strength, if m<n−1, incrementing m by 1 and repeating the loop procedure until m=n−1, in response to m=n−1, determining the location of the security tag as the n−1 th midpoint.

20 . The method of claim 17 , further comprising:
repeating the tag position estimation at least x number of times; storing x most recent determined locations of the security tag comprises; and determining an average tag position as an average of the x most recent determined locations.

Assignees

• Checkpoint Systems Inc

Inventors

• Hoehn Richard
• Hazelwood Zachary Cody
• Bradshaw Merril F
• Dobeck Brian R

Classifications

• G08B13/2462 Primary

  Asset location systems combined with EAS (inventory, tracking, logistic G06Q10/00; entrance control systems G07C9/00) · CPC title

• G06Q10/0833

  Tracking · CPC title

• G01S5/00 Primary

  Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations {(using active systems G01S13/00, G01S15/00, G01S17/00)} · CPC title

• G01S5/14

  Determining absolute distances from a plurality of spaced points of known location · CPC title

• G06Q10/087

  Inventory or stock management, e.g. order filling, procurement or balancing against orders · CPC title