Mobile robot and controlling method of the same

• US 8,954,191 B2
• Filed: 03/05/2010
• Issued: 02/10/2015
• Est. Priority Date: 03/06/2009
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Yi, Dong Hoon, Kim, Young Gie, Yoon, Jeong Suk, Lee, Seong Soo, Lee, Jei Hun, Baek, Seung Min, Choi, Yoo Jin, Na, Sang Ik, Choe, Su Uk, Kim, Yie Bin
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): Figueroa, Jaime
• Application Number:
  US12/718,380
• Publication Number:
  US 20100228394A1
• Time in Patent Office: 1,803 Days
• Field of Search: 700/245, 700/251, 700/253, 700/259, 318/568.11, 318/568.12, 318/568.16, 318/568.19, 701/26, 701/28, 901/1, 901/46, 901/47, 345/419, 702/152, 382/153, 382/154, 382/190, 382/201, 382/285
• US Class Current: 700/253
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• 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 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30

Abstract

Disclosed is a mobile robot and a controlling method of the same. An entire movement region is divided into a plurality of regions, and a partial map is gradually made by using feature points of a plurality of images of the divided regions. Then, the map is compensated into a closed curved line, thereby making an entire map. Furthermore, when the mobile robot is positioned at a boundary of neighboring regions of the cleaning region, the boundary where a closed curved line is formed, the mobile robot compensates for its position based on a matching result between feature points included in the map, and feature points extracted from images captured during a cleaning process.

Claims

1. A method for a mobile robot, the method comprising:

dividing an entire region to be cleaned into a plurality of movement regions;

obtaining image information at a predetermined time interval while moving within each of the plurality of movement regions;

extracting feature points from the obtained image information, and making sub maps corresponding to each of the plurality of movement regions based on the extracted feature points;

determining whether respective movement paths, generated by movement of the mobile robot, corresponding to the each of the plurality of movement regions form a closed curved line by checking whether a starting moving point and an ending moving point of the respective movement paths are the same as each other;

compensating a sub map having a movement path, not forming a closed curved line, by connecting a starting point and an ending point of the movement path; and

making a map of the entire region by connecting the sub maps.

2. The method of claim 1, further comprising calculating position information varied according to the movement of the mobile robot.

3. The method of claim 2, wherein the step of obtaining image information comprises obtaining two or more images at different positions of the movement region.

4. The method of claim 3, further comprising matching feature points of the two more images with each other.

5. The method of claim 4, wherein the step of making a map comprises making a map on a current movement position based on the matching information of the feature points, and the calculated position information.

6. The method of claim 1, comprising;

obtaining image information of a cleaning region corresponding to one of a plurality of the sub maps to be cleaned at predetermined time intervals while performing a cleaning process along the one of the sub maps;

extracting feature points from the obtained image information, and matching extracted feature points with feature points included in the one of the sub maps; and

compensating for a position of the mobile robot based on a matching result between the feature points,

wherein the compensated position of the mobile robot is performed when the mobile robot is positioned at a boundary between the one sub map and neighboring sub maps of the plurality of the sub maps, the boundary where a closed curved line is formed.

7. The method of claim 6, wherein the step of compensating for a position of the mobile robot comprises compensating for a position of the mobile robot when the number of the matched feature points is more than a reference value.

8. The method of claim 6, wherein the step of compensating for a position of the mobile robot comprises re-executing at least one of the method steps when the number of the matched feature points is less than a reference value.

9. A mobile robot, comprising:

a detection unit configured to obtain image information at a predetermined time interval while moving within each of a plurality of movement regions; and

a control unit configured to divide an entire region to be cleaned into the plurality of movement regions, to extract feature points from the obtained image information, to make sub maps corresponding to each of the plurality of movement regions based on the extracted feature points, to determine whether respective movement paths, generated by movement of the mobile robot, corresponding to the each of the plurality of movement regions form a dosed curved line by checking whether a starting moving point and an ending moving point of the respective movement paths are the same as each other, to compensate a sub map having a movement path, not forming a closed curved line, by connecting a starting point and an ending point of the movement path and to make a map of the entire region by connecting the sub maps.

10. The mobile robot of claim 9, further comprising a position detection unit configured to calculate position information varied according to the movement of the mobile robot.

11. The mobile robot of claim 10, wherein the control unit comprises:

an image processor configured to match the extracted feature points of two or more images with each other; and

a movement controller configured to control movement of the mobile robot.

12. The mobile robot of claim 11, wherein the control unit is configured to make a map on a current movement position based on the matching information of the feature points, and the calculated position information.

13. The mobile robot of claim 9, wherein the control unit is configured to extract feature points from image information obtained while performing a cleaning process along a pre-made map, and to match the extracted feature points with feature points included in the map,

wherein the control unit is configured to compensate for its position based on a matching result between the feature points.

14. A mobile robot, comprising:

detector configured to obtain image information at a time interval while moving within each of a plurality of movement regions; and

a controller configured to divide a region to be cleaned into the plurality of movement regions, to extract feature points from the obtained image information, to make sub maps corresponding to each of the plurality of movement regions based on the extracted feature points, to determine whether respective movement paths, generated by movement of the mobile robot, corresponding to the each of the plurality of movement regions form a closed figure by checking whether a starting moving point of the figure and an ending moving point of the figure are the same as each other, to compensate a sub map having a movement path that forms an open figure, by connecting a starting point and an ending point of the open figure, and to make a map of the entire region by connecting the sub maps.

15. The mobile robot of claim 14, further comprising a position detector configured to calculate position information which varies according to the movement of the mobile robot.

16. The mobile robot of claim 15, wherein the controller comprises:

an image processor configured to match the extracted feature points of two or more images with each other; and

a movement controller configured to control movement of the mobile robot.

17. The mobile robot of claim 16, wherein the controller is configured to make a map on a current movement position based on the matching information of the feature points, and the calculated position information.

18. The mobile robot of claim 14, wherein the controller is configured to extract feature points from image information obtained while performing a cleaning process along a pre-made map, and to match the extracted feature points with feature points included in the map, wherein the control unit is configured to compensate for its position based on a matching result between the feature points.