ROBOT CLEANER AND METHOD FOR CONTROLLING THE SAME

• US 20130340201A1
• Filed: 06/21/2013
• Published: 12/26/2013
• Est. Priority Date: 06/25/2012
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Jang, Jaewon, Park, Sungil, Kim, Hwang
• Granted Patent: US 9,775,476 B2
• Time in Patent Office: Days
• US Class Current: 15/319
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: A47L 9/009 Carrying-vehicles; Arrangements of trollies or wheels; Means for avoiding mechanical obstacles

Abstract

A robot cleaner and a method for controlling the same are disclosed. The robot cleaner includes a body provided with a suction portion and a slope formed to be inclined at a lower end thereof, an auxiliary front wheel disposed at a rear side of the slope, a main wheel disposed at a rear side of the auxiliary front wheel and arranged such that a height of the main wheel is variable with respect to the body, and a driving unit to lower or raise the main wheel with respect to the body, wherein the driving unit lowers the main wheel when the auxiliary front wheel enters a stepped portion. The robot cleaner is capable of climbing up a higher stepped portion than in conventional cases.

Claims

1. A robot cleaner comprising:

a body provided with a suction portion;

an auxiliary front wheel disposed at the body;

a main wheel disposed at a rear side of the auxiliary front wheel and arranged such that a height of the main wheel is variable with respect to the body; and

a driving unit to lower or raise the main wheel with respect to the body,

wherein the driving unit lowers the main wheel when the auxiliary front wheel enters a stepped portion.

2. The robot cleaner according to claim 1, wherein a height of the auxiliary front wheel with respect to the body is fixed.

3. The robot cleaner according to claim 1, wherein:

when the main wheel is lowered with respect to the body, an area of the main wheel exposed outside of the body increases; and

when the main wheel is raised with respect to the body, the area of the main wheel exposed outside of the body decreases.

4. The robot cleaner according to claim 1, wherein the driving unit raises the main wheel when the main wheel contacts an upper surface of the stepped portion.

5. The robot cleaner according to claim 1, wherein the driving unit adjusts the height of the main wheel to make the body level when the body is inclined by the auxiliary front wheel.

6. The robot cleaner according to claim 1, wherein the driving unit comprises:

an elastic member, one end of the elastic member being connected to one end of a main wheel housing adapted to accommodate the main wheel; and

an actuator to pull the elastic member to lower the main wheel with respect to the body.

7. The robot cleaner according to claim 6, wherein the actuator comprises:

a rack connected to the other end of the elastic member;

a pinion to move the rack forward or backward; and

a driving motor to rotate the pinion.

8. The robot cleaner according to claim 7, wherein the rack is engaged with the pinion and moved to cause tensile deformation of the elastic member such that the main wheel is lowered.

9. A method for controlling a robot cleaner comprising the steps of:

determining whether an auxiliary front wheel installed at a body of the robot cleaner enters a stepped portion;

lowering a main wheel of the robot cleaner with respect to the body when the auxiliary front wheel enters the stepped portion;

determining whether the main wheel enters the stepped portion; and

raising the main wheel with respect to the body when the main wheel enters the stepped portion.

10. The method according to claim 9, wherein, during the lowering step, the main wheel is lowered until the body becomes level.

11. The method according to claim 9, wherein, during the raising step, the main wheel is raised until the body becomes level.

12. The method according to claim 9, wherein, during the step of determining whether the auxiliary front wheel enters the stepped portion, whether the auxiliary front wheel enters the stepped portion is determined by determining whether load applied to the main wheel increases.

13. The method according to claim 9, wherein, during the step of determining whether the auxiliary front wheel enters the stepped portion, whether the auxiliary front wheel enters the stepped portion is determined by determining whether the body is inclined for a predetermined time in a manner that a front side of the body is at a higher position than a rear side of the body.

14. The method according to claim 9, wherein, during the step of determining whether the main wheel enters the stepped portion, whether the main wheel enters the stepped portion is determined by determining whether load applied to the main wheel is reduced.

15. The method according to claim 9, wherein, during the step of determining whether the main wheel enters the stepped portion, whether the main wheel enters the stepped portion is determined by determining whether the body is inclined for a predetermined time in a manner that a rear side of the body is at a higher position than a front side of the body.

16. The method according to claim 9, wherein, during the step of determining whether the auxiliary front wheel enters the stepped portion, whether the auxiliary front wheel enters the stepped portion is determined by determining whether rotational power applied to the main wheel increases.

17. The method according to claim 9, wherein, during the step of determining whether the main wheel enters the stepped portion, whether the main wheel enters the stepped portion is determined by determining whether rotational power applied to the main wheel decreases.

18. A robot cleaner comprising:

a body provided with a suction portion;

an auxiliary front wheel disposed at the body;

a main wheel disposed at a rear side of the auxiliary front wheel and arranged such that a height of the main wheel is variable with respect to the body;

a controller to control a driving unit adapted to lower or raise the main wheel with respect to the body; and

a sensor to transmit a signal to the controller;

wherein the controller lowers or raises the main wheel according to a signal transmitted from the sensor.

19. The robot cleaner according to claim 18, wherein the sensor provides information used to determine inclination of the body.

20. The robot cleaner according to claim 18, wherein the sensor provides information on variation in load applied to the main wheel or variation in rotational power applied to the main wheel.