System and method for autonomous mopping of a floor surface

• US 10,258,214 B2
• Filed: 10/06/2017
• Issued: 04/16/2019
• Est. Priority Date: 01/06/2010
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Dooley, Michael J., Case, James Philip, Romanov, Nikolai
• Primary Examiner(s): Jen, Ian
• Application Number:
  US15/726,536
• Publication Number:
  US 20180092500A1
• Time in Patent Office: 557 Days
• CPC Class Codes: A47L 11/30 by suction
• 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 11/4036 Parts or details of the surface treating tools
• CPC Class Codes: A47L 11/4061 Steering means; Means for avoiding obstacles; Details related to the place where the driver is accommodated
• CPC Class Codes: A47L 11/4066 Propulsion of the whole machine
• CPC Class Codes: A47L 11/4088 Supply pumps; Spraying devices; Supply conduits
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: B25J 11/0085 Cleaning
• CPC Class Codes: G05B 2219/39219 Trajectory tracking
• CPC Class Codes: G05D 1/021 specially adapted to land vehicles
• CPC Class Codes: G05D 1/0212 with means for defining a desired trajectory involving a plurality of land vehicles G05D1/0287
• CPC Class Codes: G05D 1/0219 ensuring the processing of the whole working surface

Abstract

A mobile robot configured to travel across a residential floor or other surface while cleaning the surface with a cleaning pad and cleaning solvent is disclosed. The robot includes a controller for managing the movement of the robot as well as the treatment of the surface with a cleaning solvent. The movement of the robot can be characterized by a class of trajectories that achieve effective cleaning. The trajectories include sequences of steps that are repeated, the sequences including forward and backward motion and optional left and right motion along arcuate paths.

Claims

1. A method of cleaning a space with a mobile robot, the method comprising:

applying, by the mobile robot, a cleaning solution to a floor surface forward of a cleaning assembly of the mobile robot;

moving, by a drive system, the mobile robot forward a first distance along a forward trajectory from a forward trajectory starting location to a forward trajectory ending location such that at least a portion of the cleaning assembly moves across the applied cleaning solution;

subsequent to moving the mobile robot along the forward trajectory, moving, by the drive system, the mobile robot backward a second distance along a backward trajectory from a backward trajectory starting location to a backward trajectory ending location, the second distance being less than the first distance and the backward trajectory starting location being the same as the forward trajectory ending location; and

repeating the steps of applying the cleaning solution, moving the mobile robot forward, and moving the mobile robot backward, wherein each backward trajectory ending location is a starting location for a subsequent forward trajectory.

2. The method of claim 1, wherein the forward trajectory comprises a first arcuate trajectory, and the backward trajectory comprises a second arcuate trajectory.

3. The method of claim 1, wherein the forward trajectory comprises a first straight trajectory, and the backward trajectory comprises a second straight trajectory.

4. The method of claim 1, wherein the first distance forward is twice as large as the second distance backward.

5. The method of claim 1, the method further comprising:

subsequent to moving the mobile robot along the backward trajectory, moving the mobile robot to the right a third distance along a rightward trajectory; and

subsequent to moving the mobile robot along the rightward trajectory, moving the mobile robot to the left a fourth distance along a leftward trajectory, wherein the third distance is equivalent to the fourth distance.

6. The method of claim 5, wherein the third distance is less than one width of the cleaning assembly of the mobile robot.

7. The method of claim 1, the method further comprising:

determining a position and orientation of the mobile robot;

directing, by a motion controller system, the drive system to move the mobile robot over the floor surface until each traversable section of the floor surface has been traversed.

8. The method of claim 1, wherein movement along the forward trajectory comprises a movement forward by the first distance and a movement to the left by a third distance, and wherein movement along the backward trajectory comprises a backward movement by the second distance and a movement to the right by a fourth distance.

9. The method of claim 1, wherein the first distance is between approximately one width of the cleaning assembly and five widths of the cleaning assembly.

10. The method of claim 1, wherein the first distance is no more than double the width of the cleaning assembly.

11. The method of claim 1, wherein the second distance is between approximately one third of a width of the cleaning assembly and four widths of the cleaning assembly.

12. The method of claim 1, wherein an elapsed time of five to sixty seconds occurs between cleaning solution applications.

13. The method of claim 12, wherein an elapsed time of fifteen to thirty seconds occurs between cleaning solution applications.

14. The method of claim 1, wherein a cleaning sheet of the cleaning assembly mechanically agitates the cleaning solution on the floor surface during forward and backward movement.

15. The method of claim 1, wherein a nozzle is configured to apply the cleaning solution onto the floor surface in front of the cleaning assembly.

16. The method of claim 1, wherein the cleaning assembly comprises a cleaning sheet configured to move the applied cleaning solution to another portion of the floor surface.

17. A mobile robot comprising:

a nozzle configured to apply a cleaning solution to a floor surface in accordance with a cleaning plan;

a cleaning assembly; and

a drive system configured to move the mobile robot in accordance with the cleaning plan, wherein the cleaning plan comprises;

applying, by the mobile robot, the cleaning solution to the floor surface forward of the cleaning assembly of the mobile robot;

moving, by a drive system, the mobile robot forward a first distance along a forward trajectory from a forward trajectory starting location to a forward trajectory ending location such that at least a portion of the cleaning assembly moves across the applied cleaning solution;

subsequent to moving the mobile robot along the forward trajectory, moving, by the drive system, the mobile robot backward a second distance along a backward trajectory from a backward trajectory starting location to a backward trajectory ending location, the second distance being less than the first distance and the backward trajectory starting location being the same as the forward trajectory ending location; and

repeating the steps of applying the cleaning solution, moving the mobile robot forward, and moving the mobile robot backward, wherein each backward trajectory ending location is a starting location for a subsequent forward trajectory.

18. The mobile robot of claim 17, wherein the cleaning assembly comprises a cleaning sheet configured to move the applied cleaning solution to another portion of the floor surface.

19. The mobile robot of claim 17, wherein the forward trajectory comprises a first arcuate trajectory, and the backward trajectory comprises a second arcuate trajectory.

20. The mobile robot of claim 17, wherein the forward trajectory comprises a first straight trajectory, and the backward trajectory comprises a second straight trajectory.