Mobile robot and method of controlling the same

• US 10,349,798 B2
• Filed: 05/17/2017
• Issued: 07/16/2019
• Est. Priority Date: 05/17/2016
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Jun, Woochan, Sung, Chulmo
• Primary Examiner(s): Jos, Basil T.
• Application Number:
  US15/597,531
• Publication Number:
  US 20170332862A1
• Time in Patent Office: 790 Days
• CPC Class Codes: A47L 11/00 Machines for cleaning floors, carpets, furniture, walls, or wall coverings
• CPC Class Codes: A47L 11/33 having means for storing dirt
• CPC Class Codes: A47L 11/4061 Steering means; Means for avoiding obstacles; Details related to the place where the driver is accommodated
• CPC Class Codes: A47L 11/4066 Propulsion of the whole machine
• CPC Class Codes: A47L 11/4069 Driving or transmission means for the cleaning tools
• CPC Class Codes: A47L 2201/022 Recharging of batteries
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: A47L 2201/06 Control of the cleaning action for autonomous devices; Automatic detection of the surface condition before, during or after cleaning
• CPC Class Codes: A47L 5/22 with rotary fans
• CPC Class Codes: A47L 9/00 Details or accessories of suction cleaners, e.g. mechanical means for controlling the suction or for effecting pulsating action; Storing devices specially adapted to suction cleaners or parts thereof; Carrying-vehicles specially adapted for suction cleaners
• CPC Class Codes: A47L 9/2826 the condition of the floor
• CPC Class Codes: A47L 9/2852 Elements for displacement of the vacuum cleaner or the accessories therefor, e.g. wheels, casters or nozzles
• CPC Class Codes: A47L 9/2873 Docking units or charging stations for autonomous or robotic vacuum cleaners A47L2201/02
• CPC Class Codes: A47L 9/2884 Details of arrangements of batteries or their installation
• CPC Class Codes: A47L 9/30 Arrangement of illuminating devices
• CPC Class Codes: B25J 5/007 mounted on wheels
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 17/00 Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
• CPC Class Codes: G01S 17/46 Indirect determination of position data
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G05D 1/0231 : using optical position detecting means position-fixing by using electromagnetic waves other than radio waves, e.g. optical position detecting means G01S5/16
• CPC Class Codes: G05D 1/024 : in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0246 : using a video camera in combination with image processing means
• CPC Class Codes: G05D 1/0248 : in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0274 : using mapping information stored in a memory device navigation using map-matching G01C21/30
• CPC Class Codes: Y10S 901/01 : Mobile robot

Abstract

A mobile robot of the present disclosure includes a first pattern emission unit configured to emit a first patterned light downward and forward from the main body on a floor of an area to be cleaned; and an image acquisition unit configured to acquire an image of first patterned light emitted by the first pattern emission unit and is incident on an obstacle, so as to determine an obstacle based on a pattern detected from the acquired image. Accordingly, based on the information on the nearby obstacles, by determining whether the mobile robot is in a stuck state where traveling of the mobile robot is limited by a plurality of obstacles, and by setting up an escape for traveling, traveling state of the mobile robot and obstacles may be determined rapidly and a corresponding operation may be performed, thereby enabling effective traveling to escape from the stuck state.

Claims

1. A mobile robot, comprising:

a main body configured to travel in an area to be cleaned and to provide suction to a floor of the area;

a camera provided on a front portion of the main body and configured to capture an image of a prescribed area facing the front portion of the main body;

a first light source provided on the front portion of the main body and configured to emit a first patterned light downward to a first sub-area of the prescribed area;

a second light source provided on the front portion of the main body and below the first light source, the second light source being configured to emit a second patterned light to a second sub-area of the prescribed area, the second sub-area being above the first sub-area; and

a controller configured to;

identify a first optical pattern, corresponding to the first patterned light, in the image captured by the camera,

detect an obstacle based on at least one of a shape of the first optical pattern or a position of the first optical pattern in the image,

detect a second optical pattern corresponding to the second patterned light in the image captured by the camera, wherein the controller detects the obstacle further based on at least one of a shape of the second optical pattern or position of the second optical pattern in the image, and

cause the main body to move relative to the obstacle,

wherein controller, when causing the main body to move relative to the obstacle, is further configured to;

determine that the mobile robot is stuck in a region having a plurality of obstacles, including the detected obstacle and one or more additional obstacles, when mobile robot is positioned in the region for at least a threshold duration,

detect, based on determining that mobile robot is stuck in the region, attributes of two or more of the obstacles in the region,

identify, based on the attributes of two or more of the obstacles in the region, an escape path, and

control the main body to travel along the escape path.

2. The mobile device of claim 1, wherein the controller is further configured to:

measure a height of one of the obstacles in the region based on the shape of the second optical pattern or the position of the second optical pattern in the image.

3. The mobile device of claim 1, wherein the controller, when identifying the escape path, is further configured to:

determine, based on the height of the one of the obstacles in the region, whether the main body can pass over the obstacle, and

include the one of the obstacles in the region in the escape path when the main body can pass over the obstacle.

4. The mobile robot of claim 1, wherein the controller is further configured to determine that the mobile robot is stuck in the region when the mobile robot remains in the region after changing a movement of the main body at least a predetermined number of times.

5. The mobile robot of claim 1, wherein the controller, when identifying the escape path, is further configured to:

identify two of the obstacles adjacent to the mobile body;

identify a space between the two obstacles;

determine, based on attributes of the two obstacles, whether the main body can move within the space between the two obstacles, and

including the space in the escape path when the main body can move within the space.

6. The mobile robot of claim 5, wherein the controller, when identifying the escape path, is further configured to:

identify, when the main body cannot move within the space between the two obstacles, another pair of the obstacle adjacent to the main body;

identify another space between the other pair of obstacles;

determine, based on attributes of the other pair of obstacles, whether the main body can move within the other space between the other pair of obstacles, and

include the other space in the escape path when the main body can move within the other space.

7. The mobile robot of claim 1, wherein the controller, when identifying the escape path, is further configured to:

detect attributes of the obstacles in the region,

generate a map of the region based on the attributes of the obstacles,

analyze the map to identify, as the escape path, a route through the region, wherein the main body can move within the route.

8. The mobile robot of claim 7, wherein the controller, when detecting the attributes of the obstacles in the region, is further configured to:

cause the main body to rotate at a given location,

capture, using the camera, another image during the rotation,

identify another first optical pattern, corresponding to the first patterned light, in the other image captured by the camera, and

detect the attributes of the obstacles based on at least one of a shape of the other first optical pattern or a position of the other first optical pattern in the other image.

9. The mobile robot of claim 8, wherein the attributes of the obstacles in the region include respective distances between the obstacles and the given location and locations of one or more lateral edges of the obstacles, and

wherein the controller is further configured to determine, based on the locations of the lateral edges of the obstacles, sizes of spaces between the obstacles.

10. The mobile robot of claim 1, wherein the first patterned light includes a horizontal portion, and

wherein the controller is further configured to:

determine at least one of a location, a size, or a shape of one of the obstacles based on a shape or a length of a portion of the first optical pattern that corresponds to the horizontal portion of the first patterned light.

11. The mobile robot of claim 10, wherein a reference location in the captured image is associated with a given distance from the mobile body, and

wherein the controller, when determining the at least one of the location, the size, or the shape of the one of the obstacles is further configured to:

determine the one of the obstacles is located closer than the given distance from the mobile body when the portion of the first optical pattern is located above the reference location in the image.

12. The mobile robot of claim 10, wherein the controller, when determining the at least one of the location, the size, or the shape of the one of the obstacles is further configured to:

identify a location of a lateral edge of the obstacle based on a bend in the portion of the first optical pattern, and identify a space adjacent to the lateral edge.

13. The mobile robot of claim 10, wherein the controller is further configured to determine that an obstacle is not located within the given distance when the portion of the first optical pattern is located at the reference location in the image.

14. The mobile robot of claim 13, wherein the controller, when identifying the escape path, is further configured to:

include, in the escape path, a space in front of the main body based on determining that the portion of the first optical pattern is located at the reference location in the image.

15. The mobile robot of claim 14, wherein the controller is further configured to:

identify a particular length of a portion of the image associated with the space is sufficiently wide for the main body, and

include the space in front of the main body in the escape path based on determining that a width of the portion of the first optical pattern in the image is equal to or greater than the particular length.

16. The mobile robot of claim 1, wherein the controller is further configured to:

change the escape path when another obstacle is detected while the main body is moving through the escape path.

17. The mobile robot of claim 16, wherein the controller is further configured to:

count a number of times that the escape path changes,

determine that the main body has escaped the region when the main body reaches in an area without an obstacle within a predetermined distance and when the number of times that the escape path changes is less than a threshold value, and

output an error message when the number of times that the escape path changes is equal to or greater than the threshold value before reaching the area without an obstacle.

18. The mobile robot of claim 17, wherein the controller is further configured to:

reset the number of times that the escape path changes to zero when the mobile body travels at least a predetermined distance without another obstacle being detected.

19. The mobile robot of claim 1, wherein the controller is further configured to:

store the escape path, and

use the stored escape path when the mobile robot returns to the region.