Electric field map generation device, method, program, and localization device

Patent metadata

Field	Value
Publication number	US-11689301-B2
Application number	US-201917054415-A
Country	US
Kind code	B2
Filing date	Apr 22, 2019
Priority date	May 14, 2018
Publication date	Jun 27, 2023
Grant date	Jun 27, 2023

Abstract

Time and effort to generate an electric field map to realize high-accuracy positioning is reduced. In an electric field map generation device (10) that generates an electric field map in which RSSI obtained when radio waves transmitted from a beacon (60) are observed at each of a plurality of points in the same space is associated with each of coordinates at the plurality of points, a radio wave strength acquisition unit (12) acquires RSSI observed at each of at least three observation points different in distance from the beacon (60), a space propagation characteristics estimation unit (14) estimates space propagation characteristics of the radio waves transmitted from the beacon (60) in the same space using the acquired RSSI at the observation points, a radio wave strength estimation unit (16) estimates RSSI at estimation points on the basis of the estimated space propagation characteristics and distances between the estimation points different from the observation points and the beacon (60), and a generation unit (18) generates the electric field map (26) using the RSSI at the observation points and the estimation points.

First claim

The invention claimed is:

1. A computer-implemented method for generating an electronic field map of a space, the method comprising:
receiving first radio wave strength data observed at each of a first set of points, wherein the first set of points include at least three distinct points with respectively distinct distances in the space from a location of a radio wave transmitter;
determining, based on the received first radio wave strength data, space propagation characteristics of radio waves from the radio wave transmitter in the space, wherein the space propagation characteristics of radio waves depend on a distance from the radio wave transmitter;
receiving a point, wherein the point is distinct from points in the first set of points;
determining a pattern for estimating a radio wave strength data using at least the determined space propagation characteristics, wherein the pattern depends on a distance between the point and the radio wave transmitter;
determining, based on the determined pattern, a second radio wave strength data at the point; and
generating, based at least on the determined second radio wave strength data of a combination of the received first radio wave strength data and the determined second radio wave strength data, the electronic field map of the space.

2. The computer-implemented method of claim 1 , the method further comprising:
receiving, based on a plurality of measurement of radio waves from the radio wave transmitter at the first set of points, a plurality of radio wave strength data;
normalizing the plurality of radio wave strength data; and
receiving, based on the largest radio wave strength of the normalized plurality of radio strength data, the first radio wave strength data observed at each of the first set of points.

3. The computer-implemented method of claim 1 , the method further comprising:
receiving the radio wave strength data from at least each of the three points in the first set of points of each of a plurality of radio wave transmitters;
determining each of the space propagation characteristics of radio waves from each of the plurality of radio wave transmitters;
determining each of radio wave strength data for measuring radio waves from each of the plurality of radio wave transmitters at the second point; and
generating the electronic field map by associating a combination of:
each point in the first set of points and the second point,
the plurality of radio wave transmitters,
the received radio wave strength data, and
the determined radio wave strength data.

4. The computer-implemented method of claim 3 , the method further comprising:
receiving third radio wave strength data, wherein the third radio wave strength data correspond to radio waves originating from each of the plurality of radio wave transmitters measured at an unknown point; and
determining, based on the received third radio wave strength data and the generated electronic field map, coordinates of the unknown point.

5. The computer-implemented method of claim 1 , wherein the radio wave transmitter transmits a beacon signal, the beacon signal including a beacon identifier, the beacon identifier representing the radio wave transmitter.

6. The computer-implemented method of claim 1 , wherein the pattern for estimating a radio wave strength data is based on approximating a radio wave propagation curved line using the received first set of radio wave strength data according to an optimization method.

7. A system for generating an electronic field map of a space, the system comprises:
a processor; and
a memory storing computer-executable instructions that when executed by the processor cause the system to:
receive first radio wave strength data observed at each of a first set of points, wherein the first set of points include at least three distinct points with respectively distinct distances in the space from a location of a radio wave transmitter;
determine, based on the received first radio wave strength data, space propagation characteristics of radio waves from the radio wave transmitter in the space, wherein the space propagation characteristics of radio waves depend on a distance from the radio wave transmitter;
receive a point, wherein the point is distinct from points in the first set of points;
determine a pattern for estimating a radio wave strength data using at least the determined space propagation characteristics, wherein the pattern depends on a distance between the point and the radio wave transmitter;
determining, based on the determined pattern, a second radio wave strength data at the point; and
generate, based at least on the determined second radio wave strength data of a combination of the received first radio wave strength data and the determined second radio wave strength data, the electronic field map of the space.

8. The system of claim 7 , the computer-executable instructions when executed further causing the system to:
receive, based on a plurality of measurement of radio waves from the radio wave transmitter at the first set of points, a plurality of radio wave strength data;
normalize the plurality of radio wave strength data; and
receive, based on the largest radio wave strength of the normalized plurality of radio strength data, the first radio wave strength data observed at each of the first set of points.

9. The system of claim 7 , the computer-executable instructions when executed further causing the system to:
receive the radio wave strength data from at least each of the three points in the first set of points of each of a plurality of radio wave transmitters;
determine each of the space propagation characteristics of radio waves from each of the plurality of radio wave transmitters;
determine each of radio wave strength data for measuring radio waves from each of the plurality of radio wave transmitters at the second point; and
generate the electronic field map by associating a combination of:
each point in the first set of points and the second point,
the plurality of radio wave transmitters,
the received radio wave strength data, and
the determined radio wave strength data.

10. The system of claim 9 , the computer-executable instructions when executed further causing the system to:
receive third radio wave strength data, wherein the third radio wave strength data correspond to radio waves originating from each of the plurality of radio wave transmitters measured at an unknown point; and
determine, based on the received third radio wave strength data and the generated electronic field map, coordinates of the unknown point.

11. The system of claim 7 , wherein the radio wave transmitter transmits a beacon signal, the beacon signal including a beacon identifier, the beacon identifier representing the radio wave transmitter.

12. The system of claim 7 , wherein the pattern for estimating a radio wave strength data is based on approximating a radio wave propagation curved line using the received first set of radio wave strength data according to an optimization method.

13. A computer-readable non-transitory recording medium storing computer-executable instructions that when executed by a processor cause a computer system to:
receive first radio wave strength data observed at each of a first set of points, wherein the first set of points include at least three distinct points with respectively distinct distances in the space from a location of a radio wave transmitter;
determine, based on the received radio wave strength data, space propagation characteristics of radio waves from the radio wave transmitter in the space, wherein the space propagation characte

Assignees

• Nippon Telegraph & Telephone

Inventors

• Abe Hirofumi
• Ochiai Keihiro
• Seshimo Hitoshi

Classifications

• H04W64/00

  Locating users or terminals {or network equipment} for network management purposes, e.g. mobility management · CPC title

• G01S5/02525

  Gathering the radio frequency fingerprints · CPC title

• G01S5/02524 Primary

  Creating or updating the radio-map · CPC title

• H04B17/318 Primary

  Received signal strength · CPC title

• H04B17/391

  Modelling the propagation channel · CPC title