Method for recognizing location using built-in camera and device thereof

• US 20070123308A1
• Filed: 09/07/2006
• Published: 05/31/2007
• Est. Priority Date: 11/28/2005
• Status: Active Grant

• Current Assignee: Kaifi, LLC (Intellectual Discovery Co., Ltd.)
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Kim, Jae-Ho, Sihn, Gyung-Chul
• Granted Patent: US 7,689,001 B2
• Time in Patent Office: Days
• US Class Current: 455/566
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 13/867 Combination of radar systems with cameras
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 3/784 using a mosaic of detectors
• CPC Class Codes: G01S 5/0045 Transmission from base station to mobile station G01S5/009 takes precedence
• CPC Class Codes: G01S 5/0236 Assistance data, e.g. base station almanac
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves

Abstract

The present invention relates to a location recognition device for recognizing a location by a mobile terminal having a camera and a method thereof. In the above method, the location recognition device photographs a location recognition tag storing location recognition information, and measures a distance to the location recognition tag. Subsequently, the location recognition device analyzes an image of the photographed location recognition tag, and recognizes location information corresponding to the location recognition tag and direction information of the photographed location recognition tag. Accordingly, a location of the mobile terminal is measured by using information of the measured distance and the recognized location information and direction information. In this case, an absolute location coordinate or a logic location coordinate is stored in the location recognition tag. In addition, the location recognition tags are arranged so that using the location recognition tags achieves a desired precision in a predetermined physical area.

Claims

1. A method for recognizing a location by a mobile terminal having a built-in camera, the method comprising:

a) photographing a location recognition tag storing location recognition information;

b) measuring a distance to the location recognition tag;

c) analyzing an image of the photographed location recognition tag, and obtaining location information corresponding to the location recognition tag;

d) obtaining direction information of the photographed location recognition tag; and

e) calculating a mobile terminal location by using the distance information measured in b), the location information obtained in c), and the direction information obtained in d).

2. The method of claim 1, wherein the direction information obtained in d) is offset information of an offset state of the location recognition tag based on the mobile terminal, and the offset information is obtained by analyzing a photographing angle of the photographed location recognition tag.

3. The method of claim 1, wherein the distance information in b) is measured by the camera when an auto focusing operation of the camera is performed.

4. The method of claim 1, wherein the distance information in b) is measured by a distance measuring sensor using infrared rays or ultrasonic waves.

5. The method of claim 1, wherein the location recognition tags are arranged so that a desired precision for using the location recognition tags at a predetermined physical area may be achieved, and the location recognition tags are formed as one-dimensional or two-dimensional barcode types.

6. The method of claim 1, wherein, in e), the mobile terminal location is calculated through a triangulation measuring algorithm by using the distance information, the location information, and the direction information corresponding to the three or more location recognition tags.

7. The method of any one of claim 1 to claim 6, wherein the location recognition tag stores location information of one among an absolute location coordinate and a logic location coordinate.

8. A location recognition device for recognizing a location by using a built-in camera, the location recognition device comprising:

an image photographing unit for photographing a plurality of location recognition tags that are arranged in a predetermined physical area and respectively store location recognition information, and for performing a digital image process;

a distance measuring unit for measuring a distance to the location recognition tag;

an image analyzing unit for analyzing an image of the location recognition tag processed by the image photographing unit, and obtaining corresponding location information and direction information of the location recognition tag; and

a location recognizing unit for recognizing a user location by using distance information measured by the distance measuring unit, and the location information and the direction information obtained by the image analyzing unit.

9. The location recognition device of claim 8, further comprising a tag location information storage unit for storing location coordinate information of a location of the location recognition tag, and logic location coordinate information corresponding to the location coordinate information.

10. The location recognition device of claim 8 or claim 9, wherein the location recognizing unit transmits the information obtained by the image analyzing unit to an external location managing server, receives location information calculated by the external location managing server, and recognizes a user location.

11. The location recognition device of claim 8, further comprising a distance measuring sensor for measuring a distance to the location recognition tag by using infrared rays or ultrasonic waves.

12. The location recognition device of claim 8 or claim 9, wherein, when the image photographing unit photographs three or more location recognition tags from one position, the location recognition unit recognizes the user location through a triangular measuring algorithm by using the distance information of the distances to the three or more location recognition tags measured by the distance measuring unit and the location and direction information of the three or more locations and directions obtained by the image analyzing unit.