Autonomous Surface Cleaning Robot

• US 20150128996A1
• Filed: 11/12/2013
• Published: 05/14/2015
• Est. Priority Date: 11/12/2013
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Romanov, Nikolai, Dooley, Michael J., Case, James Phillip
• Granted Patent: US 9,427,127 B2
• Time in Patent Office: Days
• US Class Current: 134/6
• CPC Class Codes: A47L 11/125 with supply of cleaning agents
• CPC Class Codes: A47L 11/284 having reciprocating tools
• CPC Class Codes: A47L 11/34 Machines for treating carpets in position by liquid, foam, or vapour, e.g. by steam
• CPC Class Codes: A47L 11/4005 Arrangements of batteries or cells; Electric power supply arrangements
• CPC Class Codes: A47L 11/4008 Arrangements of switches, indicators or the like
• 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 11/408 Means for supplying cleaning or surface treating agents
• CPC Class Codes: A47L 11/4083 Liquid supply reservoirs; Preparation of the agents, e.g. mixing devices
• CPC Class Codes: A47L 11/4088 Supply pumps; Spraying devices; Supply conduits
• 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 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• 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

Abstract

A mobile floor cleaning robot includes a body defining a forward drive direction, a drive system, a cleaning system, and a controller. The cleaning system includes a pad holder, a reservoir, a sprayer, and a cleaning system. The pad holder has a bottom surface for receiving a cleaning pad. The reservoir holds a volume of fluid, and the sprayer sprays the fluid forward the pad holder. The controller is in communication with the drive and cleaning systems. The controller executes a cleaning routine that includes driving in the forward direction a first distance to a first location, then driving in a reverse drive direction a second distance to a second location. From the second location, the robot sprays fluid in the forward drive direction but rearward the first location. The robot then drives in alternating forward and reverse drive directions while smearing the cleaning pad along the floor surface.

Claims

1. A mobile robot comprising:

a robot body defining a forward drive direction;

a drive system supporting the robot body to maneuver the robot across a floor surface;

a cleaning assembly disposed on the robot body, the cleaning assembly comprising;

a pad holder configured to receive a cleaning pad having a center and lateral edges; and

a fluid applicator configured to apply fluid to the floor surface; and

a controller in communication with the drive system and the cleaning assembly, the controller controlling the drive system and fluid applicator while executing a cleaning routine comprising;

applying fluid to a floor surface area substantially equal to a footprint area of the robot; and

returning the robot to the floor surface area in a movement pattern that moves the center and lateral edges of the cleaning pad separately through the floor surface area to moisten the cleaning pad with the applied fluid.

2. The robot of claim 1, wherein the cleaning routine further comprises applying fluid to the floor surface at an initial volumetric flow rate to moisten the cleaning pad, the initial volumetric flow rate being relatively higher than a subsequent volumetric flow rate when the cleaning pad is moistened.

3. The robot of claim 1, wherein the fluid applicator applies fluid to a floor surface area in front of the cleaning pad and in the forward drive direction of the mobile robot.

4. The robot of claim 3, wherein the fluid is applied to a floor surface area previously occupied by the cleaning pad.

5. The robot of claim 4, wherein the previously occupied floor surface area is stored on a map accessible to the controller.

6. The robot of claim 4, wherein fluid is applied to a floor surface area the robot has backed away from by a distance of at least one robot footprint length immediately prior to applying fluid.

7. The robot of claim 1, wherein executing the cleaning routine further comprises moving the cleaning pad in a birdsfoot motion forward and backward along a center trajectory, forward and backward along a trajectory to a left side of and heading away from a starting point along the center trajectory, and forward and backward along a trajectory to a right side of and heading away from a starting point along the center trajectory.

8. The robot of claim 1, wherein the drive system comprises right and left drive wheels disposed on corresponding right and left portions of the robot body, a center of gravity of the robot is positioned forward of the drive wheels, causing a majority of an overall weight of the robot to be positioned over the pad holder.

9. The robot of claim 8, wherein the overall weight of the robot is distributed between the pad holder and the drive wheels at a ratio of 3 to 1.

10. The robot of claim 8, wherein the overall weight of the robot is between about 2 lbs. and about 3 lbs.

11. The robot of claim 1, wherein the robot body and the pad holder both define substantially rectangular foot prints.

12. The robot of claim 1, further comprising a vibration motor disposed on a top portion of the pad holder.

13. A mobile floor cleaning robot comprising:

a robot body defining a forward drive direction;

a drive system supporting the robot body to maneuver the robot across a surface the drive system comprising right and left drive wheels disposed on corresponding right and left portions of the robot body; and

a cleaning assembly disposed on the robot body, the cleaning assembly comprising;

a pad holder disposed forward of the drive wheels and having a top portion and a bottom portion, the bottom portion having a bottom surface arranged within between about ½

cm and about1½

cm of the surface and configured to receive a cleaning pad, the bottom surface of the pad holder comprising at least 40% of a surface area of a footprint of the robot; and

an orbital oscillator having less than 1 cm of orbital range disposed on the top portion of the pad holder,

wherein the pad holder is configured to permit more than 80 percent of the orbital range of the orbital oscillator to be transmitted from the top of the received cleaning pad to the bottom surface of the received cleaning pad.

14. The robot of claim 13, wherein orbital range of the orbital oscillator is less than cm during at least part of a cleaning run.

15. The robot of claim 14, wherein the drive system drives forward and backward while oscillating the cleaning pad.

16. The robot of claim 14, wherein the drive system drives in a birdsfoot motion to move the cleaning pad forward and backward along a center trajectory, forward and backward along a trajectory to a left side of and heading away from a starting point along the center trajectory, and forward and backward along a trajectory to a right side of and heading away from a starting point along the center trajectory.

17. The robot of claim 13, wherein the cleaning pad has a top surface attached to the bottom surface of the pad holder and the top of the pad is substantially immobile relative to the oscillating pad holder.

18. The robot of claim 13, wherein the cleaning assembly further comprises at least one post disposed on the top portion of the pad holder, the at least one post sized for receipt by a corresponding aperture defined by the robot body.

19. The robot of claim 18, wherein the at least one post has a cross sectional diameter varying in size along its length.

20. The robot of claim 18, wherein the at least one post comprises a vibration dampening material.

21. The robot of claim 13, wherein the cleaning assembly further comprises:

a reservoir to hold a volume of fluid; and

a fluid applicator in fluid communication with the reservoir, the fluid applicator configured to apply the fluid along the forward drive direction forward of the pad holder.

22. The robot of claim 21, wherein the cleaning pad is configured to absorb about 90% of the fluid volume held in the reservoir.

23. A method of operating a mobile floor cleaning robot, the method comprising:

driving in a forward drive direction defined by the robot a first distance to a first location while moving a cleaning pad carried by the robot along a floor surface supporting the robot, the cleaning pad having a center and lateral edges;

driving in a reverse drive direction, opposite the forward drive direction, a second distance to a second location while moving the cleaning pad along the floor surface;

from the second location, applying fluid to an area substantially equal to a footprint area of the robot on the floor surface in the forward drive direction forward of the cleaning pad but rearward of the first location; and

returning the robot to the area in a movement pattern that moves the center and lateral edges of the cleaning pad separately through the area to moisten the cleaning pad with the applied fluid.

24. The method of claim 23, further comprising driving in a left drive direction or a right drive direction while driving through the applied fluid in the alternating forward and reverse directions after spraying fluid on the floor surface.

25. The method of claim 23, wherein applying fluid on the floor surface comprises spraying fluid in multiple directions with respect to the forward drive direction.

26. The method of claim 23, wherein the second distance is at least equal to a length of one footprint area of the robot.

27. The method of claim 23, wherein the mobile floor cleaning robot comprises:

a robot body defining the forward drive direction and having a bottom portion;

a drive system supporting the robot body and configured to maneuver the robot over the floor surface;

a pad holder disposed on the bottom portion of the robot body and configured to hold the cleaning pad; and

a fluid applicator housed by the robot body and in fluid communication with a fluid reservoir.

28. The method of claim 27, wherein the cleaning pad disposed on a bottom portion of the pad holder absorbs about 90% of the fluid contained in the reservoir.