Robot cleaner and operating method thereof

• US 20050137749A1
• Filed: 05/04/2004
• Published: 06/23/2005
• Est. Priority Date: 12/22/2003
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Jeon, Hyeong-Shin, Im, Hyoung-Bin
• Granted Patent: US 7,359,766 B2
• Time in Patent Office: Days
• US Class Current: 700/245
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• 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 1/0234 using optical markers or beacons optical beacons per se G01S1/70
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93

Abstract

A robot cleaner comprises a suction unit installed within a cleaner body, for sucking dirt on a floor; a driving unit for moving the cleaner body; a wheel installed at a bottom of the cleaner body to be contacted with the floor, and rotated by movement of the cleaner body; a detecting unit for detecting whether the wheel is rotated; and a control unit for controlling the driving unit in response to signal from the detecting unit. Accordingly, the robot cleaner can smoothly and continuously carry out a cleaning operation, even when the robot cleaner is abnormally stopped due to an obstacle which is not previously recognized in traveling.

Claims

1. A robot cleaner comprising:

a suction unit installed within a cleaner body, for sucking dirt on a floor;

a driving unit for moving the cleaner body;

a wheel installed at a bottom of the cleaner body to be contacted with the floor, and rotated by movement of the cleaner body;

a detecting unit for detecting whether the wheel is rotated; and

a control unit for controlling the driving unit in response to signal from the detecting unit.

2. The robot cleaner of claim 1, wherein the detecting unit comprises:

an indicating means formed on the wheel, wherein a state thereof is changed while the wheel is rotated; and

a detecting means installed near the wheel, for detecting a state of the indicating means.

3. The robot cleaner of claim 2, wherein the indicating means comprises a plurality of coated layers made as materials having optical absorptance different from each other are alternately applied onto an outer circumferential surface of the wheel in a circumferential direction;

and

the detecting means comprises an optical sensor for emitting light to the coated layer and for sensing reflectivity variation of light reflected from the coated layer.

4. The robot cleaner of claim 1, wherein the control unit outputs a signal for controlling the driving unit in order to move the cleaner body in the opposite direction to the normally traveling direction, when the detecting unit detects a rotation stoppage of the wheel.

5. A robot cleaner comprising:

a suction unit provided at a cleaner body, for sucking dirt on a floor;

a driving wheel installed at the cleaner body and rotated by the driving motor to move the cleaner body;

at least one auxiliary wheel installed at a bottom of the cleaner body, for supporting the cleaner body on the floor in a state of being in contact with the floor, and rotated by movement of the cleaner body; and

a detecting unit installed near the auxiliary wheel and for detecting whether the auxiliary wheel is rotated.

6. The robot cleaner of claim 5, wherein the detecting unit comprises:

an indicating means formed as materials having optical absorptance different from each other are alternately applied onto an outer circumferential surface of the auxiliary wheel in a circumferential direction; and

an optical sensor installed near the auxiliary wheel, for emitting light to the indicating means and for sensing reflectivity variation of light reflected from the indicating means.

7. The robot cleaner of claim 5, wherein the auxiliary wheel is rotatably installed at the cleaner body in such a manner that a partial portion of the auxiliary wheel is inserted into a recessed portion formed in a bottom of the cleaner body, and protruded portions protruded from both ends of the auxiliary wheel are inserted into insertion grooves formed both sides of an inner circumferential surface of the recessed portion.

8. An operating method of a robot cleaner comprising:

a first step of carrying out cleaning operation by moving by itself and sucking dirt on a floor;

a second step of detecting whether the cleaner normally travels by sensing whether a wheel supporting the cleaner on a floor and rotated by movement of the cleaner is rotated; and

a third step of extricating the cleaner from a place where a rotation stoppage of the wheel is detected in the second step.

9. The method of claim 8, further comprising a step of maintaining cleaning operation by moving by itself and sucking dirt on the floor, when the rotation of the wheel is detected in the second step which is performed after the third step.

10. The method of claim 8, further comprising a step aborting the operation of the cleaner, when the rotation stoppage of the wheel is detected after the second and the third steps are repeatedly performed more than predetermined times.

11. The method of claim 8, wherein the second step is performed by emitting light to the wheel and sensing a variation of the light reflected from the wheel by an optical sensor.

12. The method of claim 8, wherein the third step is performed by reversely rotating a driving motor for moving the cleaner so as to move the cleaner in a direction opposite to the normally traveling direction of the cleaner.