System and method for tracking assets within a monitored environment

• US 7,916,023 B2
• Filed: 01/19/2007
• Issued: 03/29/2011
• Est. Priority Date: 01/31/2006
• Status: Active Grant

• Current Assignee: Zebra Technologies Corporation
• Original Assignee: Zebra Enterprise Solutions Corp. (Zebra Technologies Corporation)
• Inventors: Rado, Rodrigo
• Primary Examiner(s): Wu; Daniel
• Assistant Examiner(s): Tun; Nay
• Application Number:
  US11/624,848
• Publication Number:
  US 20070182556A1
• Time in Patent Office: 1,530 Days
• Field of Search: 340/571, 340/572.1, 340/539.13, 340/539.1, 340/679, 340/686.1, 340/539.26, 414/139.4, 414/803, 700/115, 700/116, 700/213, 700/215
• US Class Current: 340/572.1
• CPC Class Codes: G01S 5/02 using radio waves using satellite radio beacon systems for determining position G01S19/00
• CPC Class Codes: G01S 5/0294 Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering

Abstract

A system associates change in the state of an asset to an event trigger within a monitored environment. This environment includes a plurality of assets and a tag transmitter positioned on each asset and operative for transmitting a wireless RE signal based on an event trigger based on one of at least the change in state of an asset and change in location of the asset. A plurality of spaced apart access points receive an RF signal transmitted from a tag transmitter. A processor is operatively connected to the access points and collect possible candidates as assets associated with the event trigger and assigning a numerical score to each candidate to determine which asset is best associated with the event trigger.

Claims

1. A system for associating a change in a state or location of an asset to an event trigger within a monitored environment, comprising:

a plurality of assets;

a tag transmitter positioned on each asset and configured to transmit a wireless RF signal based on an event trigger based on one of at least the change in the state of the asset on which the tag transmitter is positioned and the change in the location of the asset;

a plurality of spaced apart access points positioned at known locations within the monitored environment and configured to receive the wireless RF signal transmitted from the tag transmitter; and

a processor operatively connected to said access points, wherein said processor is configured to collect possible candidates as assets associated with the event trigger and configured to assign a numerical score to each candidate to determine which asset is best associated with the event trigger, wherein the numerical score of each candidate is based upon how well each candidate matches an event associated with the event trigger according to at least one rule configured to assess each candidate with the event.

2. The system according to claim 1, and further comprising at least one sensor within the monitored environment, wherein the sensor is operative with the tag transmitter, wherein the sensor is configured to sense the event associated with the event trigger, and wherein the sensor is configured to transmit data to one of at least the tag transmitter positioned on one of theplurality of assets and one of the plurality of access points.

3. The system according to claim 2, and further comprising an interrogator positioned within the monitored environment, wherein the interrogator is configured to interrogate the tag transmitter positioned on one of the plurality of assets to begin transmission.

4. The system according to claim 1, wherein said monitored environment comprises a rental car lot, wherein said assets comprise a plurality of rental cars, wherein the event trigger is the presence of at least one of the rental cars in an exit lane of the rental car lot, and wherein the processor is configured to determine which rental car is best associated with being present in the exit lane.

5. The system according to claim 1, wherein said monitored environment comprises a cargo container terminal, wherein said assets comprise at least one of a cargo container and a container handling equipment, wherein the event trigger is the passage of the cargo container or container handling equipment through a port device field of a terminal port, and wherein the processor is configured to determine which cargo container or container handling equipment is best associated with passing through the terminal port.

6. The system according to claim 1, wherein said monitored environment comprises a marine terminal, wherein said assets comprise a plurality of cargo containers, wherein the event trigger is one of a crane picking a container off a ship or the crane dropping the container onto a truck or a rail car, and wherein the processor is configured to determine which cargo container is best associated with being picked off the ship or dropped onto the truck or rail car.

7. The system according to claim 1, wherein said processor is configured to geolocate a tag transmitter.

8. The system according to claim 7, wherein said processor is configured to correlate a signal as a first-to-arrive signal and configured to conduct differentiation of first-to-arrive signals.

9. The system according to claim 1, wherein said processor is configured to report the candidate associated with the event trigger when its numerical score is above a predetermined minimum numerical score.

10. The system according to claim 9, wherein said processor is configured to report the candidate associated with the event trigger that has the highest numerical score.

11. The system according to claim 10, wherein said processor is configured to wait a predetermined time if the numerical score is not above the minimum numerical score and configured to report the candidate associated with the event trigger having the best numerical score below the minimum numerical score.

12. The system of claim 1, wherein the numerical score of each candidate is based upon how well each candidate matches the event associated with the event trigger according to at least two rules of a rule set, wherein each rule is configured to assess each candidate with the event, and wherein at least one rule of the rule set is weighed differently than another rule of the rule set.

13. A system for associating a change in a state or location of a cargo container to an event trigger within a cargo container terminal, comprising:

a plurality of cargo containers;

a tag transmitter positioned on each cargo container and configured to transmit a wireless RF signal based on an event trigger based on one of at least the change in the state of the cargo container on which the tag transmitter is positioned and the change in the location of the cargo container within the terminal;

a plurality of spaced apart access points positioned at known locations within the terminal and configured to receive the wireless RF signal transmitted from the tag transmitter; and

a processor operatively connected to said access points wherein said processor is configured to collect possible candidates as cargo containers associated with the event trigger and configured to assign a numerical score to each candidate to determine which cargo container is best associated with the event trigger, wherein the numerical score of each candidate is based upon how well each candidate matches an event associated with the event trigger according to at least one rule configured to assess each candidate with the event.

14. The system according to claim 13, and further comprising at least one sensor within the terminal, wherein the sensor is operative with the tag transmitter, wherein the sensor is configured to sense the event associated with the event trigger, and wherein the sensor is configured to transmit data to one of at least the tag transmitter positioned on one of the plurality of cargo containers and one of the plurality of access points.

15. The system according to claim 14, and further comprising container handling equipment on which said sensor is mounted.

16. The system according to claim 13, and further comprising an interrogator positioned at the terminal, wherein the interrogator is configured to interrogate the tag transmitter positioned on one of the plurality of cargo containers to begin transmission.

17. The system according to claim 13, wherein said processor is configured to geolocate the tag transmitter positioned on one of the plurality of cargo containers.

18. The system according to claim 17, wherein said processor is configured to correlate a signal as a first-to-arrive signal and configured to conduct differentiation of first-to-arrive signals.

19. A method for associating a change in a state or location of an asset to an event trigger in a monitored environment having a plurality of assets to be tracked, wherein a tag transmitter positioned on each asset to be tracked is configured to transmit a wireless RF signal based upon the event trigger, wherein a plurality of spaced apart access points positioned at known locations within the monitored environment are configured to receive the wireless RF signal transmitted from the tag transmitter, and wherein a processor is operatively connected to said access points, the method comprising:

generating an event trigger based on one of at least the change in the state of the asset and the change in the location of the asset to indicate the gain or loss of the asset within the monitored environment;

collecting, by the processor, possible candidates as assets associated with the event trigger; and

assigning, by the processor, a numerical score to each candidate to determine which asset is best associated with the event trigger, wherein the numerical score of each candidate is based upon how well each candidate matches an event associated with the event trigger according to at least one rule configured to assess each candidate with the event.

20. The method according to claim 19, wherein the event trigger comprises a loader picking up a container among a plurality of containers.

21. The method according to claim 19, wherein the event trigger comprises the detection of the presence of a vehicle in an exit lane of a rental car lot for automated check-out.

22. The method according to claim 19, further comprising generating the event trigger from a fixed location when the asset is moved.

23. The method according to claim 19, further comprising generating the event trigger from a cargo container terminal, wherein the event trigger is the passage of a cargo container through a port of the cargo container terminal.

24. The method according to claim 19, further comprising reporting the candidate associated with the event trigger when its numerical score is above a predetermined minimum numerical score.

25. The method according to claim 24, further comprising reporting the candidate with the event trigger that has the highest numerical score.

26. The method according to claim 25, further comprising waiting a predetermined time if the numerical score is not above the minimum numerical score and reporting the candidate associated with the event trigger having the best numerical score below the minimum numerical score.

27. The method of claim 19, wherein assigning the numerical score of each candidate is based upon how well each candidate matches the event associated with the event trigger according to at least two rules of a rule set, wherein each rule is configured to assess each candidate with the event, and wherein at least one rule of the rule set is weighed differently than another rule of the rule set.