ROBOT CLEANER AND METHOD FOR CONTROLLING THE SAME

• US 20160104044A1
• Filed: 10/13/2015
• Published: 04/14/2016
• Est. Priority Date: 10/14/2014
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: NOH, Dongki, BAEK, Seungmin, KIM, Yeonsoo
• Granted Patent: US 10,133,930 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B25J 9/1664 characterised by motion, path, trajectory planning
• CPC Class Codes: B25J 9/1676 Avoiding collision or forbidden zones
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: G05D 1/0248 in combination with a laser lasers per se H01S
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light
• CPC Class Codes: G06T 7/74 involving reference images or patches
• CPC Class Codes: G06V 20/10 Terrestrial scenes scenes under surveillance with static cameras G06V20/52; scenes perceived from the exterior of a vehicle G06V20/56; scenes perceived from the interior of a vehicle G06V20/59
• CPC Class Codes: Y10S 901/01 Mobile robot

Abstract

A method for controlling a robot cleaner configured to project light of a predetermined pattern to a floor of an area in front thereof in a specific direction and to acquire an image of the area to which the light is projected, according to the present disclosure, includes: (a) acquiring a front view image of the robot cleaner; (b) detecting the pattern from the image acquired in (a); and (c) discriminating a pattern formed by reflected light from a pattern formed by light directly projected from the robot cleaner, from among patterns indicated in the acquired image, on the basis of geometrical characteristics defined by a projection direction of the light and the direction of an optical axis in which the image is acquired when two or more patterns are detected from the image.

Claims

1. A method for controlling a robot cleaner configured to project light of a predetermined pattern to a floor of an area in front thereof in a specific direction and to acquire an image of the area to which the light is projected, comprising:

(a) acquiring an image of an area in front of the robot cleaner;

(b) detecting the pattern from the image acquired in step (a); and

(c) discriminating a valid pattern formed by reflected light from a pattern formed by light directly projected from the robot cleaner, from among patterns indicated in the acquired image, on the basis of geometrical characteristics defined by a projection direction of the light and the direction of an optical axis in which the image is acquired when two or more patterns are detected from the image.

2. The method of claim 1, wherein, when the position of the pattern formed by the light directly projected to the floor is defined as a reference position in the acquired image, step (c) comprises selecting a pattern detected at the reference position as the valid pattern when one of the two or more patterns is detected at the reference position and at least one other pattern is detected from a region above the reference position.

3. The method of claim 1, wherein, when the position of the pattern formed by the light directly projected to the floor is defined as a reference position in the acquired image, step (c) comprises selecting a pattern detected from a region above the reference position as the valid pattern when patterns are respectively detected from the region above the reference position and a region below the reference position.

4. The method of claim 3, further comprising (d) obtaining a distance to an object on the basis of the valid pattern.

5. The method of claim 4, wherein in step (d), the distance to the object is obtained on the basis of a location relation between the reference position and the valid pattern in the acquired image.

6. The method of claim 5, wherein step (d) comprises determining that the distance to the object is shorter as the distance between the reference position and the valid pattern increases.

7. The method of claim 2, further comprising (d) updating the reference position,

wherein step (d) comprises:

(d-1) acquiring an image of an area in front of the robot cleaner;

(d-2) detecting a pattern formed by light directly projected to the floor from the robot cleaner from the image acquired in step (d-1);

(d-3) comparing a distance between the pattern detected in step (d-2) and the reference position with a predetermined allowable distance; and

(d-4) updating the reference position to the position of the pattern detected in step (d-2) on the basis of a comparison result in step (d-3).

8. The method of claim 7, wherein step (d) further comprises:

(d-5) moving the robot cleaner upon determining that the distance obtained in step (d-2) is greater than the allowable distance in step (d-2);

(d-6) acquiring an image of an area in front of the robot cleaner at a changed position of the robot cleaner;

(d-7) detecting a pattern formed by light directly projected to the floor from the robot cleaner from the image acquired in step (d-6);

(d-8) comparing the position of the pattern detected in step (d-7) with the position of the pattern detected in step (d-2); and

(d-9) updating the reference position to the position of the pattern detected in step (d-2) on the basis of a comparison result in step (d-8).

9. The method of claim 8, wherein step (d-9) comprises updating the reference position to the position of the pattern detected in step (d-2) when the position of the pattern detected in step (d-7) is the same as the position of the pattern detected in step (d-2).

10. The method of claim 1, wherein when the position of the pattern formed by the light directly projected to the floor is defined as a reference position in the acquired image,

(e) estimating a position at which the boundary between the object and the floor will be detected on the basis of the reference position and a position of a pattern generated by light directly projected to an object located in front of the robot cleaner;

and

(f) selecting a boundary from patterns detected in step (b) on the basis of the position at which the boundary will be detected and estimated in step (e).

11. The method of claim 10, wherein step (f) comprises selecting a pattern closest to the position at which the boundary will be detected, which is estimated in (e), from the patterns detected in step (b).