System and method for collaborative resource tracking

• US 8,896,442 B1
• Filed: 08/30/2013
• Issued: 11/25/2014
• Est. Priority Date: 11/09/2009
• Status: Expired due to Fees

• Current Assignee: Carnegie Mellon University
• Original Assignee: Carnegie Mellon University
• Inventors: Khan, Usman, Moura, Jos M., Kar, Soummya
• Primary Examiner(s): Tweel, Jr., John A
• Application Number:
  US14/014,670
• Time in Patent Office: 452 Days
• Field of Search: 340/539.13, 340/539.1, 340/568.1, 340/10.1, 340/10.4, 340/572.1
• US Class Current: 340/539.13
• CPC Class Codes: G06Q 10/0833 Tracking
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services

Abstract

A system and method for locating, tracking, and monitoring resource in large-scale facilities is disclosed herein. The system is based on a sensor network and is efficient, scalable, and requires only short-range communication. The system allows for sensor-to-sensor communication as well as the traditional sensor-to-anchor communication to effectively eliminate long-range communications. In order to perform resource localization and tracking, the present invention pairs each resource with an inexpensive, low-powered sensor possessing minimal communication and computation capabilities. The sensors communicate with only nearby resources or anchors and those resources communicate with their nearby resources or anchors until a wireless, linked network of resources and anchors is formed.

Claims

1. A wireless sensor for tracking a location of an associated target mobile asset that is moveable, along with other mobile assets, within a multi-dimensional region, the wireless sensor for the target mobile asset comprising:

a two-way wireless communication module for two-way wireless communication with, when in range, a plurality of other wireless sensors that are each configured to transmit and receive data wirelessly, wherein the plurality of other wireless sensors comprises;

a plurality of mobile wireless sensors that are each associated with one of the other mobile assets; and

a plurality of known-location wireless sensors that are located at separate, known locations such that the plurality of known-location wireless sensors cover the multi-dimensional region; and

a processor that is programmed to determine an updated location of the wireless sensor for the target mobile asset using an iterative localization algorithm and based on at least one of (i) data exchanged with a subset of the plurality of other wireless sensors that are nearby to the target mobile asset and (ii) the known locations of the plurality of known-location wireless sensors.

2. The wireless sensor of claim 1, wherein the processor is programmed to determine the updated location of the wireless sensor for the target mobile asset using the iterative localization algorithm by performing steps that comprise:

identifying, by the wireless sensor, nearby wireless sensors from the plurality of other wireless sensors;

choosing the subset of nearby wireless sensors from the identified nearby wireless sensors such that the wireless sensor for the target mobile asset lies within a convex hull defined by the subset of nearby wireless sensors; and

updating the location of the wireless sensor for the target mobile asset based on location estimates of the subset of nearby wireless sensors determined from data exchanged with the subset of nearby wireless sensors.

3. The wireless sensor of claim 2, wherein the processor is programmed to choose the subset of nearby wireless sensors based on performance of a convex hull inclusion test.

4. The wireless sensor of claim 3, wherein the processor is programmed to determine the updated location of the wireless sensor for the target mobile asset based on a linear combination of the location estimates of the subset of nearby wireless sensors.

5. The wireless sensor of claim 4, wherein coefficients for the linear combination comprise barycentric coordinates.

6. The wireless sensor of claim 1, wherein data exchanged with the subset of nearby wireless assets comprise received signal strength data.

7. The wireless sensor of claim 1, wherein data exchanged with the subset of nearby wireless assets comprise time of arrival data.

8. The wireless sensor of claim 1, wherein the two-way wireless communication module comprises an IEEE 802.15.4 standard-compliant two-way communication module.

9. The wireless sensor of claim 1, wherein the two-way communication module is for transmitting wirelessly the updated location information determined by the processor to a remote central processor via one or more network hops.

10. The wireless sensor of claim 1, wherein the plurality of known-location wireless sensors are at separate fixed locations.

11. The wireless sensor of claim 1, wherein the wireless sensor is affixed to the target mobile asset.

12. A method of tracking a location of an associated target mobile asset that is moveable, along with other mobile assets, within a multi-dimensional region, the method comprising:

associating a wireless sensor with the target mobile asset, wherein the wireless sensor comprises a processor;

exchanging data, by the wireless sensor, with, when in range, a plurality of other wireless sensors that are each configured to transmit and receive data wirelessly, wherein the plurality of other wireless sensors comprises;

a plurality of mobile wireless sensors that are each associated with one of the other mobile assets; and

a plurality of known-location wireless sensors that are located at separate, known locations such that the plurality of known-location wireless sensors cover the multi-dimensional region; and

determining, by the processor of the wireless sensor, an updated location of the wireless sensor affixed the target mobile asset using an iterative localization algorithm and based on at least one of (i) data exchanged with a subset of the plurality of other wireless sensors that are nearby to the target mobile asset and (ii) the known locations of the plurality of known-location wireless sensors.

13. The method of claim 12, wherein determining the updated location of the wireless comprises:

identifying, by the wireless sensor, nearby wireless sensors from the plurality of other wireless sensors;

choosing, by the wireless sensors, the subset of nearby wireless sensors from the identified nearby wireless sensors such that the wireless sensor for the target mobile asset lies within a convex hull defined by the subset of nearby wireless sensors; and

updating the location of the wireless sensor for the target mobile asset based on location estimates of the subset of nearby wireless sensors determined from data exchanged with the subset of nearby wireless sensors.

14. The method of claim 13, wherein choosing the subset of nearby wireless sensors comprises performing of a convex hull inclusion test.

15. The method of claim 14, wherein determining the updated location of the wireless sensor for the target mobile asset comprises using a linear combination of the location estimates of the subset of nearby wireless sensors.

16. The method of claim 15, wherein coefficients for the linear combination comprise barycentric coordinates.

17. The method of claim 12, further comprising transmitting wirelessly the updated location determined by the processor to a remote central processor via one or more network hops.

18. The method of claim 12, wherein associating the wireless sensor with the target mobile asset comprises affixing the wireless sensor to the target mobile asset.

19. A system for tracking the locations of mobile assets that are moveable within a multi-dimensional region, the system comprising:

a first plurality of wireless sensors that located at separate, known locations such that the first plurality of wireless sensors cover the multi-dimensional region; and

a second plurality of wireless sensors wherein each of the second plurality of wireless sensors is associated with a separate one of the mobile assets to be tracked, wherein each of the second plurality of mobile sensors comprise;

a two-way wireless communication module for two-way wireless communication with, when in range, other wireless sensors in the first and second pluralities of wireless sensors; and

a processor that is programmed to determine an updated location of the associated mobile asset using an iterative localization algorithm and based on at least one of (i) data exchanged with a subset of the other wireless sensors that are nearby and (ii) the known locations of the first plurality of wireless sensors.

20. The system of claim 19, wherein the processors of the first plurality of wireless sensors are programmed to determine the updated location of their associated mobile asset based on a linear combination of location estimates of a subset of nearby wireless sensors in the first and second pluralities of wireless sensors.