Mobile robot and method for moving mobile robot

• US 20110137461A1
• Filed: 02/16/2010
• Published: 06/09/2011
• Est. Priority Date: 02/13/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Kong, Dong-geon, Lee, Hyoung-ki
• Granted Patent: US 8,285,482 B2
• Time in Patent Office: Days
• US Class Current: 700/253
• CPC Class Codes: G05D 1/0225 involving docking at a fixed facility, e.g. base station or loading bay parking aids B62D15/027
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30

Abstract

Disclosed is a mobile robot and method generating a path of the mobile robot, capable of quickly moving the mobile robot to a location at which the mobile robot is able to detect a docking station. A first configuration space map is built by expanding an obstacle area including an obstacle by a first thickness, and a second configuration space map is built by expanding the obstacle area by a second thickness which is less than the first thickness. A path is generated by sequentially using the first configuration space map and the second configuration space map.

Claims

1. A mobile robot comprising:

a controlling unit to estimate a position of the mobile robot by use of detection information;

an obstacle map building unit to build an obstacle map indicating an obstacle area including an obstacle based on the estimated position and obstacle detection information;

a path generating unit to expand the obstacle area by a first thickness to build a first configuration space map, expand the obstacle area by a second thickness which is less than the first thickness to build a second configuration space map, and to generate a path by sequentially using the first configuration space map and the second configuration space map; and

a moving unit to move the mobile robot along the path.

2. The mobile robot of claim 1, wherein, when the path generating unit is no longer able to generate a path in the first configuration space map, the path generating unit generates a path in the second configuration map.

3. The mobile robot of claim 2, wherein, the path generating unit recognizes that the path generating unit is no longer able to generate the path when a goal point is not present.

4. The mobile robot of claim 1, wherein, the first thickness has a dimension identical to a width of a passage used to divide an area of the obstacle area, which allows movement of the mobile robot, into at least two distinguishable areas.

5. The mobile robot of claim 1, wherein the second thickness has a dimension identical to a radius of the mobile robot.

6. The mobile robot of claim 1, wherein, after the mobile robot has moved along a path generated in the second configuration space map, when the path generating unit searches for a next goal point to generate a next path,

the path generating unit determines whether a boundary, between an unknown area including the next goal point and an empty area lacking an obstacle, has a width exceeding a predetermined width, and, when the width of the boundary exceeds the predetermined width, the mobile robot builds a first configuration space map at a current position of the mobile robot and generates the next path based on the generated first configuration space map.

7. The mobile robot of claim 1, wherein the controlling unit detects a guidance signal from a docking station and controls the path generating unit to generate a path based on the guidance signal.

8. A method of moving a mobile robot, the method comprising:

building an obstacle map indicating an obstacle area including an obstacle by use of an estimated position of the mobile robot and obstacle detection information;

building a first configuration space map by expanding the obstacle area by a first width;

building a second configuration space map by expanding the obstacle area by a second width which is less than the first width; and

generating a path by sequentially using the first configuration space map and the second configuration space map so that the mobile robot moves along the path.

9. The method of claim 8, wherein the generating of the path comprises:

generating a path in the first configuration space map; and

when the path is no longer able to be generated in the first configuration space map, generating a path in the second configuration space map.

10. The method of claim 9, further comprising determining whether a goal point is present in the first configuration space;

and

recognizing that the path is no longer able to be generated in the first configuration space when the goal point is not present.

11. The method of claim 8, wherein the first thickness has a dimension identical to a width of a passage which is used to divide an area of the obstacle area, allowing movement of the mobile robot, into at least two distinguishable areas.

12. The method of claim 11, wherein the passage has a same width as a width of a door installed in the passage.

13. The method of claim 8, wherein the second thickness has a dimension identical to a radius of the mobile robot.

14. The method of claim 8, wherein the generating of a path further comprises:

after the mobile robot has moved in a path generated in the second configuration space map, when searching for a next goal point to generate a next path, determining whether a boundary, between an unknown area including the next goal point and an empty area lacking an obstacle, has a width exceeding a predetermined width, and when the width of the boundary exceeds the predetermined width, building a first configuration space map at a current position of the mobile robot and generating the next path based on the generated first configuration space map.

15. The method of claim 8, further comprising when the mobile robot detects a signal from a docking station during movement, generating a path based on the detected signal.

16. A method of moving a mobile robot, the method comprising:

detecting an area around the mobile robot;

determining a presence of a first boundary point present at a first boundary in the area around the mobile robot, which is selected from boundaries between an unknown area determined by detecting the area around the mobile robot and an empty area around the mobile robot lacking an obstacle and has a width larger than a predetermined width;

when the first boundary point is present, moving the mobile robot to the first boundary point; and

when the first boundary point is not present, moving to a second boundary point present at a second boundary which is selected from the boundaries and has a width smaller than the predetermined width.