Robot cleaner and controlling method thereof

• US 10,758,103 B2
• Filed: 08/07/2018
• Issued: 09/01/2020
• Est. Priority Date: 08/07/2017
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Park, Jeongseop, Yoon, Sungho, Jang, Jaewon
• Primary Examiner(s): Redding, David
• Application Number:
  US16/057,394
• Publication Number:
  US 20190038105A1
• Time in Patent Office: 756 Days
• CPC Class Codes: A47L 11/161 with supply of cleaning agents
• CPC Class Codes: A47L 11/282 having rotary tools
• CPC Class Codes: A47L 11/305 the tools being disc brushes
• CPC Class Codes: A47L 11/4002 Installations of electric equipment
• CPC Class Codes: A47L 11/4011 Regulation of the cleaning machine by electric means; Control systems and remote control systems therefor
• CPC Class Codes: A47L 11/4066 Propulsion of the whole machine
• CPC Class Codes: A47L 11/4083 Liquid supply reservoirs; Preparation of the agents, e.g. mixing devices
• CPC Class Codes: A47L 2201/00 Robotic cleaning machines, i.e. with automatic control of the travelling movement or the cleaning operation
• 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 9/28 Installation of the electric equipment, e.g. adaptation or attachment to the suction cleaner; Controlling suction cleaners by electric means
• CPC Class Codes: A47L 9/2805 Parameters or conditions being sensed

Abstract

The present application relates to a robot cleaner. The robot cleaner of the present application includes: a main body which forms an external shape; a water tank which stores water; a rotation mop which is in contact with a floor while rotating and moves the main body; a drive motor which rotates the rotation mop; a motion detection unit which measures a reference motion of the main body when the rotation mop rotates; and a controller which measures a slip rate based on an actual speed of the main body measured by the motion detection unit in the reference motion and an ideal speed of the main body estimated according to driving of the drive motor, and controls an amount of water supplied to the rotation mop.

Claims

1. A robot cleaner comprising:

a main body;

a water tank which stores water;

a rotation mop which contacts a floor and moves the main body while rotating;

a drive motor which rotates the rotation mop;

a motion sensor which measures a reference motion of the main body while the rotation mop rotates; and

a controller which;

calculates a slip rate based on an actual speed of the main body measured by the motion sensor during the reference motion and an ideal speed of the main body which is estimated according to driving of the drive motor, and

controls an amount of water supplied to the rotation mop based on the slip rate.

2. The robot cleaner of claim 1, further comprising a floor sensor which senses information of the floor.

3. The robot cleaner of claim 2, wherein the controller adjusts the amount of water supplied to the rotation mop further based on the information of the floor detected by the floor sensor.

4. The robot cleaner of claim 1, wherein a speed measured by the motion sensor includes at least one of a rotation speed of the main body or a straight moving speed of the main body.

5. The robot cleaner of claim 1, wherein the motion sensor includes a gyroscopic sensor that measures a rotation speed of the main body according to rotation of the rotation mop.

6. The robot cleaner of claim 5, wherein the controller calculates the slip ratio further based on an ideal rotation speed of the main body according to the rotation of the rotation mop and an actual rotation speed of the main body measured by the gyroscopic sensor.

7. The robot cleaner of claim 1, further comprising a memory that stores data related to a correlation between at least one slip rate measured during the reference motion and a water content rate identifying a degree to which the rotation mop contains water.

8. The robot cleaner of claim 7, wherein the controller further determines an actual water content rate for the measured slip rate based on the data stored in the memory, and compares the actual water content rate with a set water content rate when adjusting the amount of water supplied to the rotation mop.

9. The robot cleaner of claim 8, wherein the controller further adjusts the amount of water supplied to the rotation mop and drives the rotation mop when the set water content rate is equal to or greater than the actual water content rate.

10. The robot cleaner of claim 8, wherein the controller further drives the rotation mop without supplying additional water to the rotation mop when the set water content rate is less than the actual water content rate.

11. The robot cleaner of claim 1, wherein the motion sensor includes an acceleration sensor which measures a straight moving speed of the main body according to the rotation of the rotation mop.

12. The robot cleaner of claim 1, further comprising a floor sensor which senses information of the floor, wherein the floor sensor includes a cliff sensor which senses a cliff on the floor in a cleaning area, and wherein the cliff sensor includes at least one light emitter and at least one light sensor.

13. The robot cleaner of claim 1, wherein the rotation mop includes a pair of spin mops having a rotation axis perpendicular to the floor.

14. A method of controlling a robot cleaner, the method comprising steps of:

performing a reference motion by the robot cleaner based on rotating a rotation mop;

measuring a motion of the robot cleaner and a motion of the rotation mop;

calculating a slip rate of the robot cleaner based on the motion of the robot cleaner and the motion of the rotation mop; and

controlling an amount of water supplied to the rotation mop based on the slip rate.

15. The method of claim 14, wherein:

performing the reference motion includes turning the robot cleaner, and

measuring the motion of the robot cleaner includes determining an actual rotation speed of the main body of the robot cleaner using a gyroscopic sensor.

16. The method of claim 15, wherein the slip rate is calculated using an ideal rotation speed of the robot cleaner corresponding to the motion of the rotation mop and the actual rotation speed of the robot cleaner.

17. The method of claim 14, wherein:

performing the reference motion includes turning the robot cleaner, and

measuring the motion of the robot cleaner includes determining an ideal rotation number of the spin mop and an actual rotation number of the spin mop operated by a drive motor, in a range of rotation angle of the robot cleaner.

18. The method of claim 14, wherein:

performing the reference motion includes the robot cleaner moving in a direction, and

measuring the motion of the robot cleaner includes determines a moving distance of the robot cleaner in the direction.

19. The method of claim 18, wherein the slip rate is calculated using an ideal speed of the robot cleaner according to the motion of the spin mop and a speed of the robot cleaner.

20. The method of claim 14, further comprising:

determining information about a material of the floor, wherein the slip rate of the robot cleaner is further determined based on the information about the material of the floor.

21. The method of claim 20, wherein the amount of water supplied to the rotation mop is controlled further based on the information about the material of floor.

22. The method of claim 14, wherein controlling the amount of water supplied to the rotation mop includes:

determining an actual water content rate of the robot cleaner based on the slip rate;

comparing a set water content rate and the actual water content rate; and

supplying water to the spin mop and driving the spin mop when the set water content rate is equal to or greater than the actual water content rate.

23. The method of claim 14, wherein controlling the amount of water supplied to the rotation mop includes:

determining an actual water content rate of the robot cleaner based on the slip rate;

comparing a set water content rate and the actual water content rate; and

driving the rotation mop without supplying water to the rotation mop when the set water content rate is smaller than the actual water content rate.

24. The method of claim 23, further comprising:

supplying water to the rotation mop after the actual water content rate becomes less than the set water content rate based on driving the rogation mop.