Object tracking and ranging

Patent metadata

Field	Value
Publication number	US-10613191-B2
Application number	US-201815982848-A
Country	US
Kind code	B2
Filing date	May 17, 2018
Priority date	Sep 7, 2017
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

A location system includes multiple master nodes located at corners of a coverage area. At least two master nodes are located on one edge of the coverage area and receive signals from a slave node within the coverage area. The at least two master nodes calculate a distance to the slave node and a location of the slave node within the coverage area.

First claim

The invention claimed is:

1. A location system comprising:
multiple master nodes located at corners of a coverage area, wherein at least two master nodes on one edge of the coverage area receive signals from a slave node within the coverage area and calculate a distance to the slave node and a location of the slave node within the coverage area, wherein the at least two master nodes are located at a same height to provide clear line of sight to slave nodes within the coverage area, and wherein the multiple master nodes define a minimum perimeter polygon such that the coverage area is entirely within such polygon, wherein the calculation of the location of the slave node is a calculation performed in accordance with following equations: X1=(D 2 +a 2 −b 2 )/2D and Y1=a 2 −X1 2 , wherein a and b are the respective distances of the slave node to the at least two master nodes, D is the distance between two master nodes, and X1,Y1 are coordinates of the slave node within the coverage area, where the coordinates of the at least two master nodes are 0,0, and 0,D.

2. The location system of claim 1 , wherein the at least two master nodes execute a LoRa time-of-flight ranging compliant communication protocol with the slave node to determine respective distances to the slave node, and wherein at least a third master node is used to ensure an object is within the polygon.

3. The location system of claim 1 , wherein the at least two master nodes are mounted in fixed positions.

4. The location system of claim 3 , wherein the fixed positions are all at a same height selected to provide clear line of sight to the slave nodes within the area of coverage.

5. The location system of claim 3 , wherein the at least two master nodes have moving positions and known distances with neighboring master nodes.

6. The location system of claim 1 , wherein the multiple master nodes comprise 4 master nodes, each positioned at a corner of a square coverage area.

7. The location system of claim 1 , wherein the at least two master nodes are mounted on a flying drone capable of remaining at a fixed position while the signals are received.

8. The location system of claim 1 , wherein the slave node is associated with an object to be tracked.

9. A method comprising:
receiving signals from a slave node within a coverage area to at least two master nodes on adjacent corners of the coverage area;
determining a range of the object from each of the at least two adjacent corners; and
calculating, via a computer, a location of the slave node within the coverage area in response to the determined ranges, wherein the at least two master nodes are located at a same height to provide clear line of sight to slave nodes within the coverage area, and wherein multiple master nodes define a minimum perimeter polygon such that the coverage area is entirely within such polygon, wherein the calculation of the location of one of the slave nodes is a calculation performed in accordance with following equations: X1=(D 2 +a 2 −b 2 )/2D and Y1=a 2 −X1 2 , wherein a and b are the respective distances of the slave node to the at least two master nodes, D is the distance between two master nodes, and X1,Y1 are coordinates of the slave node within the coverage area, where the coordinates of the at least two master nodes are 0,0, and 0,D.

10. The method of claim 9 , wherein the slave node comprises a communication system slave node and each of the at least two master nodes on adjacent corners comprise communication system master nodes.

11. The method of claim 10 , wherein the communication system master nodes execute a LoRa time-of-flight ranging compliant communication protocol with the communication system slave node.

12. The method of claim 10 , wherein the communication system master nodes are mounted in fixed positions.

13. The method of claim 12 , wherein the fixed positions are all at a similar height.

14. The method of claim 13 , wherein the height is selected to provide clear line of sight to the communication system slave nodes within coverage area.

15. The method of claim 10 , wherein the communication system slave node is associated with an object to be tracked.

16. The method of claim 10 wherein the calculation of the location of the communication system slave node is a triangulation calculation.

17. The method of claim 9 , wherein the communication system master nodes are mounted on a flying drone capable of remaining at a fixed position while the signals are received.

18. A non-transitory machine-readable storage device having instructions for execution by a processor of the machine to perform operations comprising:
receiving signals from a slave node within a coverage area at at least two master node on adjacent corners of the area of coverage;
determining a range of the slave node from each of the at least two master nodes on adjacent corners; and
calculating a location of the slave node within the coverage area in response to the determined ranges, wherein the at least two master nodes are located at a same height to provide clear line of sight to slave nodes within the coverage area, and wherein multiple master nodes define a minimum perimeter polygon such that the coverage area is entirely within such polygon, wherein the calculation of the location of one of the slave nodes is a calculation performed in accordance with following equations: X1=(D 2 +a 2 −b 2 )/2D and Y1=a 2 −X1 2 , wherein a and b are the respective distances of the slave node to the at least two master nodes, D is the distance between two master nodes, and X1,Y1 are coordinates of the slave node within the coverage area, where the coordinates of the at least two master nodes are 0,0, and 0,D.

19. The non-transitory machine-readable storage device of claim 18 , wherein the slave node comprises a communication system slave node and each of the at least two master nodes on adjacent corners comprise a communication system master node, wherein the communication system master nodes execute a LoRa time-of-flight ranging compliant communication protocol with the communication system slave node, the communication system master nodes are mounted in fixed positions at a similar height selected to provide clear line of sight to communication system slave nodes within the coverage area and wherein the calculation of the location of the communication system slave node is a triangulation calculation.

Assignees

• Honeywell Int Inc

Inventors

• Pham Hai D
• Cornett Alan
• Larson Christian
• Backes Glen
• Kolavennu Soumitri N

Classifications

• G01S2205/01

  specially adapted for specific applications · CPC title

• G01C21/28

  with correlation of data from several navigational instruments · CPC title

• G01S5/14 Primary

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

• G01S5/04

  Position of source determined by a plurality of spaced direction-finders · CPC title

• G01S1/045

  Receivers · CPC title