Wireless Tracking System And Method Utilizing Variable Location Algorithms

• US 20090251313A1
• Filed: 06/14/2009
• Published: 10/08/2009
• Est. Priority Date: 05/08/2007
• Status: Active Grant

• Current Assignee: Centrak Incorporated (Halma PLC)
• Original Assignee: Awarepoint Corporation
• Inventors: Perkins, Matthew R., Nierenberg, Nicolas C.
• Granted Patent: US 8,319,635 B2
• Time in Patent Office: Days
• US Class Current: 340/539.130
• CPC Class Codes: G01S 5/0218 Multipath in signal reception
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 5/18 using ultrasonic, sonic, or infrasonic waves
• CPC Class Codes: G08C 21/00 Systems for transmitting the position of an object with respect to a predetermined reference system, e.g. tele-autographic system
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

The present invention provides a solution to mistaken location calculations based on multipath effects. The present invention utilizes tags attached to objects that transmit signals at various power levels for reception by sensors stationed throughout a facility. Sensor readings at the various power levels are utilized to determine the location of the tagged object.

Claims

1. A method for determining a real-time location of an object within a facility, the method comprising:

transmitting a wireless first power level signal from a communication device associated with an object;

transmitting a wireless second power level signal from the communication device associated with the object;

receiving the first power level signal at at least one of a plurality of sensors positioned within a facility and receiving the second power level signal at at least one of a plurality of sensors positioned within a facility;

calculating a first power level location from the first power level signal utilizing a first location algorithm;

calculating a second power level location from the second power level signal utilizing a second location algorithm; and

determining a real-time location of the object using the first power level location and the second power level location.

2. The method according to claim 1 wherein first location algorithm is a radial basis function algorithm and the second location algorithm is a proximity detection algorithm.

3. The method according to claim 1 wherein first location algorithm is a radial basis function algorithm and the second location algorithm is a spatial diversity algorithm.

4. The method according to claim 1 wherein the first power level location and the second power level location are the same location.

5. The method according to claim 1 wherein the first power level is 1 milli-Watt and the second power level is 0.5 milli-Watt.

6. The method according to claim 1 wherein the first power level is equal to the second power level.

7. The method according to claim 1 wherein the wireless first power level signal is one of light, radiofrequency, sound and magnetic energy.

8. The method according to claim 7 wherein the wireless second power level signal is one of light, radiofrequency, sound and magnetic energy.

9. The method according to claim 1 wherein the first location algorithm and the second location algorithm are a combination of at least two of an RBF algorithm, proximity detection, minimum mean square error calculation, maximum likelihood of calculation, time difference of arrival calculation, time of arrival calculation, and angle of arrival calculation.

10. The method according to claim 1 further comprising associating the transmitting object with a second object.

11. The method according to claim 1 further comprising triggering an event.

12. The method according to claim 11 wherein the event is at least one of commencing a workflow event, changing the status of a workflow process, transmitting an alert, transmitting a report, changing the status of a computer, activating a camera, and changing the state of light.

13. A system for determining a real-time location of an object within a facility, the system comprising:

a plurality of objects, each of the plurality of objects comprising a communication device which transmits a wireless first power level signal and a wireless second power level signal;

a plurality of sensors positioned within the facility, at least one of the plurality of sensors receiving the first power level signal and at least one of the plurality of sensors receiving the second power level signal;

a server in communication with each of the plurality of sensors, the server calculating a first power level location of the object from the first power level signal utilizing a first location algorithm, calculating a second power level location of the object from the second power level signal utilizing a second location algorithm, and determining a real-time location of the object using the first power level location and the second power level location.

14. The system according to claim 13 wherein first location algorithm is a radial basis function algorithm and the second location algorithm is a proximity detection algorithm.

15. The system according to claim 13 wherein at least one of the plurality of objects is a medical device or a person.

16. A method for determining a real-time location of an object within a facility, the method comprising:

receiving a first wireless power level signal from a communication device of an object at at least one of a plurality of sensors positioned within a facility;

receiving a second wireless power level signal the communication device of the object at at least one of the plurality of sensors positioned within the facility;

calculating a first power level location from the first wireless power level signal utilizing a first location algorithm;

calculating a second power level location from the second wireless power level signal utilizing a second location algorithm; and

determining a real-time location of the object using the first power level location and the second power level location.

17. The method according to claim 16 wherein first location algorithm is a radial basis function algorithm and the second location algorithm is a proximity detection algorithm.

18. The method according to claim 16 wherein the first wireless power level signal is one of light, radiofrequency, sound and magnetic energy.

19. The method according to claim 16 wherein the second wireless power level signal is one of light, radiofrequency, sound and magnetic energy.

20. The method according to claim 16 wherein the first location algorithm and the second location algorithm are a combination of at least two of an RBF algorithm, proximity detection, minimum mean square error calculation, maximum likelihood of calculation, time difference of arrival calculation, time of arrival calculation, and angle of arrival calculation.