Wireless position location and tracking system

• US 7,616,156 B2
• Filed: 10/27/2007
• Issued: 11/10/2009
• Est. Priority Date: 10/22/2003
• Status: Active Grant

• Current Assignee: Centrak Incorporated (Halma PLC)
• Original Assignee: Awarepoint Corporation
• Inventors: Nierenberg, Nicolas C, Smith, Derek M., Baker, Joseph C., Adams, James D.
• Primary Examiner(s): Issing; Gregory C
• Application Number:
  US11/925,826
• Publication Number:
  US 20080048914A1
• Time in Patent Office: 745 Days
• Field of Search: None
• US Class Current: 342/451
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/02525 Gathering the radio frequency fingerprints
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 4/33 for indoor environments, e.g. buildings
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Techniques for accurate position location and tracking suitable for a wide range of facilities in variable environments are disclosed. In one aspect, a system for position location comprises a plurality of sensors (e.g. a network monitor, an environment sensor) for generating measurements of a plurality of sources, a plurality of objects or tags, each object generating measurements of the plurality of sources, and a processor for receiving the measurements and generating a position location for one or more objects in accordance with the received measurements. In another aspect, a position engine comprises a mapped space of a physical environment, and a processor for updating the mapped space in response to received measurements. The position engine may receive second measurements from an object within the physical environment, and generate a position location estimate for the object from the received second measurements and the mapped space.

Claims

1. An apparatus for locating and tracking a plurality of objects within an indoor facility, the indoor facility including a plurality of beacon emitters positioned therein, a plurality of network monitors, and a tag associated with each of the plurality of objects, each beacon emitter generating a radiofrequency signal, each network monitor attached to a wall outlet at a known location of the indoor facility and generating a first plurality of measurements comprising data including signal strength from each of the plurality of beacon emitters received by the network monitor, each tag generating a second plurality of measurements comprising data including signal strength from each of the plurality of beacon emitters received by each tag of the plurality of objects, the apparatus comprising:

a database storing a mapped space of the indoor facility, wherein the mapped space is a three dimensional mapped space of the indoor facility having X, Y and Z coordinates of each of the plurality of objects; and

a processor for updating the mapped space in response to the first plurality of measurements received from the plurality of network monitors to create an updated mapped space, the processor further generating a plurality of location hypotheses for the at least one object of the plurality of objects, at least one of the location hypotheses computed in response to measurements received from the updated mapped space and a tag associated with the at least one object of the plurality of objects, and the processor further generating a location estimate for the at least one object of the plurality of objects based on one or more of the plurality of location hypotheses.

2. The apparatus of claim 1 wherein the location estimate is an average of one or more of the plurality of location hypotheses.

3. The apparatus of claim 1 wherein the location estimate is a weighted average of one or more of the plurality location hypotheses.

4. The apparatus of claim 1 wherein the location estimate is computed using a filter.

5. A method for locating and tracking a plurality of objects within an indoor facility, the method comprising:

generating a fist plurality of measurements at a plurality of network monitors, the first plurality of measurements comprising data including signal strength from radiofrequency signals from a plurality of beacon emitters within the indoor facility;

generating a second plurality of measurements at a plurality of tags, each of the plurality of tags associated with an object of the plurality of objects, the second plurality of measurements comprising data including signal strength from radiofrequency signals from the plurality of beacon emitters within the indoor facility;

transmitting the first plurality of measurements and the second plurality of measurements to a position engine via at least one access point located within the indoor facility;

accessing a mapped space from a database, wherein the mapped space is a three dimensional mapped space of the indoor facility having X, Y and Z coordinates of each of the plurality of objects;

updating the mapped space in response to the first plurality of measurements from the plurality of network monitors to create an updated mapped space;

generating a plurality of location hypotheses for at least one object of the plurality of objects within the indoor facility, at least one of the location hypotheses computed in response to the updated mapped space and the second plurality of measurements received from a tag associated with the at least one object; and

generating a location estimate for the at least one object based on one or more of the plurality of location hypotheses.