Method and system for determining the position of a device in a light based positioning system using locally stored maps

• US 8,994,799 B2
• Filed: 04/13/2012
• Issued: 03/31/2015
• Est. Priority Date: 07/26/2011
• Status: Active Grant

• Current Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Original Assignee: Bytelight, Inc. (Acuity Brands, Inc.)
• Inventors: Ganick, Aaron, Ryan, Daniel
• Primary Examiner(s): WONG, ALLEN C
• Application Number:
  US13/446,506
• Publication Number:
  US 20130026224A1
• Time in Patent Office: 1,082 Days
• Field of Search: 348/61, 701/208, 701/220, 701/201, 340/531, 455/456.3, 315/294
• US Class Current: 348/61
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation

Abstract

In one aspect, the present disclosure relates to a method for determining a position of a device using a light based positioning system. In some embodiments, the method includes providing a map of positions of a plurality of light sources in a location; receiving an identification code from one or more of the plurality of light sources, wherein the identification code identifies the light source; matching the identification code to a light source on the map; and determining the position of the device by setting the position of the device to the position of the light source on the map. In some embodiments, the method includes receiving identification codes from a plurality of light sources; matching the identification codes to a plurality of light sources on the map; and determining the position of the device based on the location of the plurality of light sources on the map.

Claims

1. A method for determining a position of a mobile device using a light-based positioning system, the method comprising:

determining an approximate location of the mobile device using geo-location information not derived from visible light received at the mobile device;

downloading at the mobile device, from a remote server, a map data structure of positions of a plurality of asynchronous light sources at a location corresponding to the approximate location of the mobile device;

receiving at the mobile device an identifier broadcast from one of the asynchronous light sources of the plurality of asynchronous light sources, wherein (i) the identifier identifies the asynchronous light source, and (ii) the identifier corresponds to a pattern of distortions within an image acquired by the mobile device, the pattern of distortions being related to a modulation frequency of modulated light emitted by the asynchronous light source identified by the identifier;

matching the identifier to the asynchronous light source stored by the map data structure; and

determining the position of the mobile device by setting the position of the mobile device to the position of the asynchronous light source stored by the map data structure.

2. The method of claim 1, comprising:

receiving one or more additional identifiers each broadcast from others of the asynchronous light sources;

matching each of the one or more additional identifiers to one of the asynchronous light sources stored by the map data structure; and

determining the position of the mobile device based on (i) the position of the asynchronous light source stored by the map data structure and (ii) the positions of the others of asynchronous light sources stored by the map data structure.

3. The method of claim 1, wherein the map data structure comprises a floor plan.

4. The method of claim 1, wherein the map data structure comprises at least one of computer aided drafting files, user provided computerization, or hand drawn images.

5. The method of claim 1, wherein the asynchronous light source comprises a light emitting diode (LED).

6. The method of claim 1, wherein the asynchronous light source comprises a fluorescent light source.

7. The method of claim 1, wherein the location comprises an indoor location.

8. The method of claim 1, wherein the position of the mobile device is determined without access to a network connection.

9. The method of claim 1, wherein the geo-location information comprises at least one of GPS, GSM, WiFi, user input, accelerometer, gyroscope, digital compass, barometer, Bluetooth, or cellular tower identification information.

10. The method of claim 1, wherein the map data structure is downloaded at the mobile device via the Internet.

11. The method of claim 1, wherein each asynchronous light source emits modulated light at a different frequency of modulation.

12. The method of claim 1, wherein each asynchronous light source is a single-color light source.

13. The method of claim 12, wherein each asynchronous light source comprises one or more phosphor-converted light-emitting diodes that all emit light of approximately the same color.

14. The method of claim 1, wherein the mobile device acquires different portions of the image at different times, thereby forming the pattern of distortions on the image.

15. A mobile device for determining position using a light-based positioning system, the mobile device comprising:

an approximate location determination module configured to determine an approximate location of the mobile device using geo-location information not derived from visible light received at the mobile device;

a network interface for receiving, from a remote server, when the mobile device is at a location remote from the remote server, a map data structure of positions of a plurality of asynchronous light sources at a location corresponding to the approximately location of the mobile device;

an image sensor for receiving an identifier broadcast from one of the asynchronous light sources of the plurality of asynchronous light sources, wherein (i) the identifier identifies the asynchronous light source, and (ii) the identifier corresponds to a pattern of distortions within an image acquired by the image sensor, the pattern of distortions being related to a modulation frequency of modulated light emitted by an asynchronous light source; and

a position determination module configured to match the identifier to the asynchronous light source stored by the map data structure and determine the position of the mobile device by setting the position of the mobile device to the position of the asynchronous light source stored by the map data structure.

16. The mobile device of claim 15, wherein the position determination module is configured to receive identifiers from a plurality of asynchronous light sources, match the identifiers to the plurality of asynchronous light sources stored by the map data structure, and determine the position of the mobile device based on the positions of the plurality of asynchronous light sources stored by the map data structure.

17. The mobile device of claim 15, wherein the map data structure comprises a floor plan.

18. The mobile device of claim 15, wherein the map data structure comprises at least one of computer aided drafting files, user provided computerization, or hand drawn images.

19. The mobile device of claim 15, wherein the asynchronous light source comprises a light emitting diode (LED).

20. The mobile device of claim 15, wherein the asynchronous light source comprises a fluorescent light source.

21. The mobile device of claim 15, wherein the location comprises an indoor location.

22. The mobile device of claim 15, wherein the position of the mobile device is determined without access to a network connection.

23. The mobile device of claim 15, wherein the geo-location information comprises at least one of GPS, GSM, WiFi, user input, accelerometer, gyroscope, digital compass, barometer, Bluetooth, or cellular tower identification information.

24. The mobile device of claim 15, wherein the network interface is configured for receiving the map data structure via the Internet.

25. The mobile device of claim 15, wherein the pattern of distortions within the image results from different portions of the image being acquired by the image sensor at different times.