Optimized differential evolution for radio frequency trilateration in complex environments

Patent metadata

Field	Value
Publication number	US-10775480-B2
Application number	US-201816174326-A
Country	US
Kind code	B2
Filing date	Oct 30, 2018
Priority date	Oct 30, 2018
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

A system, device and method for wireless device localization using a differential evolution algorithm in a continuous trilateration process.

First claim

The invention claimed is:

1. A device localization method comprising:
(a) obtaining by a plurality of sensor distances between a wireless device and a vehicle;
(b) generating by trilateration of the distances a first population of a plurality of coordinate sets, each set describing a possible location in 3-D space of the device;
(c) computing fitness levels of each of the plurality of the coordinate sets by employing a fitness function based on ranging results obtained from a plurality of anchors having known positions;
(d) saving coordinates sets from the first population having a fitness level above a threshold fitness level;
(e) computing a vector offset to the saved coordinate sets based on updated ranging results from the plurality of anchors;
(f) applying the vector offset based on historical data to the saved coordinate sets to obtain a shifted population;
(g) generating a second population of a plurality of coordinate sets, each set describing a possible location in 3-D space of the device;
(h) combining the shifted population with the second population to form a combined population; and
(i) computing fitness levels of the coordinate sets in the combined population by employing the fitness function.

2. The device localization method of claim 1 further comprising:
saving the coordinate sets from the combined population having a fitness level above the threshold fitness level;
repeating operations (e) through (i) as they pertain to the combined population and to further updated ranging results from the plurality of anchors of and further repeating operations (e) through (i) on each additional combined population formed and on further updated ranging results from the plurality of anchors until the coordinate sets converge to within a defined area or a threshold number of iterations has been reached.

3. The device localization method 1 further comprising:
locating the plurality of anchors to minimize region of interest size.

4. The device localization method of claim 1 wherein the device is a wireless key and the anchors are located on a vehicle.

5. The device localization method of claim 3 further comprising:
locating the at least two of the plurality of anchors on an exterior portion of the vehicle.

6. The device localization method of claim 5 wherein at least two of the plurality of anchors are located on the same side of the vehicle as one another.

7. The device localization method of claim 5 wherein one or more of the plurality of anchors are located on an exterior portion of the vehicles and one or more of the plurality of anchors are located in the interior of the vehicle.

8. A system for localization of a wireless device comprising:
one or more processors operatively coupled to one or more non-transitory storage devices on which is stored executable computer code, which when executed by the one or more processors causes the system to perform the method of:
(a) obtaining by a plurality of sensors distances between a wireless device and a vehicle;
(b) generating by trilateration of the distances a first population of a plurality of coordinate sets, each set describing a possible location in 3-D space of the device;
(c) computing fitness levels of each of the plurality of the coordinate sets by employing a fitness function based on ranging results obtained from a plurality of anchors having known positions;
(d) saving coordinates sets from the first population having a fitness level above a threshold fitness level;
(e) computing a vector offset to the saved coordinate sets based on updated ranging results from the plurality of anchors;
(f) applying the vector offset based on historical data to the saved coordinate sets to obtain a shifted population;
(g) generating a second population of a plurality of coordinate sets, each set describing a possible location in 3-D space of the device;
(h) combining the shifted population with the second population to form a combined population; and
(i) computing fitness levels of the coordinate sets in the combined population by employing the fitness function.

9. The system for localization of a wireless device of claim 8 further comprising:
saving the coordinate sets from the combined population having a fitness level above the threshold fitness level;
repeating method operations (e) through (i) as they pertain to the combined population and to further updated ranging results from the plurality of anchors and further repeating operations (e) through (i) on each additional combined population formed and on further updated ranging results from the plurality of anchors until the coordinate sets converge to within a defined area or a threshold number of iterations has been reached.

10. The system for localization of a wireless device of claim 8 further comprising:
locating the plurality of anchors to minimize region of interest size.

11. The system for localization of a wireless device of claim 8 wherein the device is a wireless key and the anchors are located on a vehicle.

12. The system for localization of a wireless device of claim 11 further comprising:
locating the at least two of the plurality of anchors on an exterior portion of the vehicle.

13. The system for localization of a wireless device of claim 11 wherein at least two of the plurality of anchors are located on the same side of the vehicle as one another.

14. The system for localization of a wireless device of claim 11 wherein one or more of the plurality of anchors are located on an exterior portion of the vehicles and one or more of the plurality of anchors are located in the interior of the vehicle.

Assignees

• Volkswagen Ag
• Porsche Ag
• Audi Ag

Inventors

• Kong Liang
• Tolstov Oleg
• Kuklenyik Andrea
• Rill Florian

Classifications

• G01S5/0244

  Accuracy or reliability of position solution or of measurements contributing thereto · CPC title

• G07C2009/00317

  keyless data carrier having only one limited data transmission range · CPC title

• G01S13/767

  Responders; Transponders (teaching or practice apparatus for gun-aiming or gun-laying using reflecting targets or active targets F41G3/26) · CPC title

• G01S7/295 Primary

  Means for transforming co-ordinates or for evaluating data, e.g. using computers · CPC title

• G01S5/14 Primary

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