AUTONOMOUS FLOOR-CLEANING ROBOT

• US 20100257691A1
• Filed: 06/28/2010
• Published: 10/14/2010
• Est. Priority Date: 01/03/2002
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: SANDIN, Paul E., MACK, Newton E., NUGENT, David M., JONES, Joseph L.
• Granted Patent: US 8,763,199 B2
• Time in Patent Office: Days
• US Class Current: 15/319
• CPC Class Codes: A47L 11/282 having rotary 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 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
• CPC Class Codes: A47L 5/30 with driven dust-loosening tools, e.g. rotating brushes
• CPC Class Codes: A47L 5/34 with height adjustment of nozzles or dust-loosening tools
• CPC Class Codes: A47L 7/02 with driven tools for special purposes with floor-polishing tools A47L11/20
• CPC Class Codes: A47L 9/009 Carrying-vehicles; Arrangements of trollies or wheels; Means for avoiding mechanical obstacles
• CPC Class Codes: A47L 9/0411 driven by electric motor
• CPC Class Codes: A47L 9/0477 Rolls
• CPC Class Codes: A47L 9/0494 Height adjustment of dust-loosening tools
• CPC Class Codes: A47L 9/1409 Rigid filtering receptacles dust collecting receptacles for cyclones A47L9/1683
• CPC Class Codes: A47L 9/2826 the condition of the floor
• CPC Class Codes: A47L 9/2852 Elements for displacement of the vacuum cleaner or the accessories therefor, e.g. wheels, casters or nozzles
• CPC Class Codes: A47L 9/2894 Details related to signal transmission in suction cleaners
• CPC Class Codes: A47L 9/32 Handles

Abstract

A robot includes a robot housing having a substantially arcuate forward portion and a motor drive housed by the robot housing and configured to maneuver the robot on a floor surface. At least two independently driven drive wheels are moveably attached to the robot housing and biased toward the floor surface, each of the drive wheels being moveable downwardly in response to the each of the drive wheels moving over a cliff in the floor surface. A plurality of cliff sensors are disposed adjacent a forward edge of the robot housing and spaced from each other, each cliff sensor including an emitter and a detector aimed toward the floor surface and configured to receive emitter emissions reflected off of the floor surface, each cliff sensor being responsive to a cliff in the floor surface and configured to send a signal when a cliff in the floor surface is detected. The robot also includes a wheel drop sensor in communication with each drive wheel that senses when a drive wheel moves downwardly and sends a signal indicating downward movement of the pivoted drive wheel. A controller is in communication with the cliff sensors, each of the wheel drop sensors, and the motor drive to redirect the robot when a cliff in the floor surface is detected.

Claims

1. A robot comprising:

a robot housing having a substantially arcuate forward portion;

a motor drive housed by the robot housing and configured to maneuver the robot on a floor surface;

at least two independently driven drive wheels moveably attached to the robot housing and biased toward the floor surface, each of the drive wheels being moveable downwardly in response to the each of the drive wheels moving over a cliff in the floor surface;

a plurality of cliff sensors disposed adjacent a forward edge of the robot housing and spaced from each other, each cliff sensor comprising an emitter and a detector aimed toward the floor surface and configured to receive emitter emissions reflected off of the floor surface, each cliff sensor responsive to a cliff in the floor surface and configured to send a signal when a cliff in the floor surface is detected;

a wheel drop sensor in communication with each drive wheel that senses when a drive wheel moves downwardly and sends a signal indicating downward movement of the drive wheel; and

a controller in communication with the cliff sensors, each of the wheel drop sensors, and the motor drive to redirect the robot when a cliff in the floor surface is detected.

2. The robot of claim 1, further comprising at least one edge brush driven about a non-horizontal axis, at least a portion of the at least one edge brush extending beyond a peripheral edge of the robot housing to move debris while the robot is maneuvered across the floor surface.

3. The robot of claim 1, further comprising at least one edge brush rotated about a non-horizontal axis, at least a portion of the at least one edge brush periodically during a duration of time intersecting a path between at least one of the plurality of cliff sensors and the floor surface.

4. The robot of claim 1, further comprising an obstacle detection sensor including an emitter and detector configured to detect the proximity of the robot to an obstacle and transmit a detection signal to the controller.

5. The robot of claim 4, wherein the obstacle detection sensor is substantially adjacent the forward portion of the robot housing.

6. The robot of claim 1, wherein the controller is configured to initiate a collision avoidance routine that navigates the robot about objects as the robot is maneuvered across the floor surface.

7. The robot of claim 1, wherein the plurality of cliff sensors are substantially equally spaced from one another along an arc defined by the arcuate forward portion of the robot housing.

8. The robot of claim 1, wherein the at least two drive wheels are moved to an extended position when the robot is removed from the floor surface.

9. The robot of claim 1, wherein the wheel drop sensor senses when the drive wheel pivots downwardly.

10. The robot of claim 1, wherein the wheel drop sensor senses when the drive wheel extends downwardly.

11. An autonomous coverage robot comprising:

a robot housing including a substantially arcuate forward portion, as defined in a plane parallel to a floor surface;

a motor drive mounted in the robot housing and configured to maneuver the robot on a surface;

at least two drive wheel modules controlled by the motor drive comprising independently driven drive wheels moveably attached to the robot housing and biased toward the floor surface, each of the drive wheels being moveable downwardly in response to the each of the drive wheels moving over a cliff in the floor surface;

at least one edge cleaning brush driven about a non-horizontal axis, at least a portion of the at least one edge cleaning brush extending beyond a peripheral edge of the robot housing to direct debris while the robot is maneuvered across the floor surface;

a plurality of cliff sensors housed in the forward portion of the robot housing substantially near a forward edge and spaced from each other, each cliff sensor comprising an emitter and a detector aimed toward the floor surface and configured to receive emitter emissions reflected off of the surface, each cliff sensor responsive to a cliff in the floor surface;

at least one obstacle sensor, disposed at a front side of the robot, each sensor being responsive to obstacles encountered by the robot;

a wheel drop sensor, associated with each drive wheel, that senses when a drive wheel moves in a direction away from the robot housing and which sends a signal indicating a wheel drop condition of the drive wheel; and

a controller in communication with the plurality of cliff sensors, the at least one obstacle sensor, each of the wheel drop sensors, and the motor drive to redirect the robot in response to a signal from one of the plurality of cliff sensors, the at least one obstacle sensor, and at least one of the wheel sensors.

12. The robot of claim 11, wherein the at least one edge cleaning brush periodically during a duration of time occludes an emission path of the emitter of at least one of the plurality of cliff sensors as the robot is moved across the floor surface.

13. The autonomous coverage robot of claim 11, wherein the plurality of cliff sensors are substantially evenly positioned along an arc defined by the arcuate forward portion of the robot housing.

14. The autonomous coverage robot of claim 11, wherein the controller is configured to initiate a collision avoidance routine that navigates the robot about objects as the robot moves across the floor surface.

15. The autonomous coverage robot of claim 11, wherein the at least one edge cleaning brush is mounted in a recess in the robot housing in front of one of the drive wheels and adjacent the peripheral edge of the robot housing.

16. The autonomous coverage robot of claim 11, further comprising a bumper extending along a portion of the robot housing, the bumper having a bumper sensor responsive to movement of the bumper relative to the robot housing.

17. The autonomous coverage robot of claim 11, wherein the wheel drop sensor senses when the drive wheel pivots in a direction away from the robot housing.

18. The autonomous coverage robot of claim 11, wherein the wheel drop sensor senses when the drive wheel extends in a direction away from the robot housing.

19. A robot comprising:

a robot housing having a substantially arcuate forward edge;

at least two independently driven drive wheels located adjacent a lateral edge of the robot housing, each of the drive wheels being moveably attached to the robot housing and biased toward the floor surface, each of the drive wheels being moveable downwardly in response to movement of each of the drive wheels over a cliff in the floor surface;

at least three cliff sensors disposed along a contour of the arcuate forward edge of the robot housing and spaced from each other, each cliff sensor comprising an emitter and a detector aimed toward the floor surface and configured to receive emitter emissions reflected off of the floor surface, each cliff sensor being responsive to a cliff in the floor surface;

a bumper having a shape of the arcuate forward edge and extending along the robot housing to a position adjacent to the drive wheels, the bumper having a bumper sensor responsive to movement of the bumper relative to the robot housing;

a wheel drop sensor, associated with each drive wheel, that senses when a respective drive wheel moves downwardly, and which sends a signal indicating downward movement of the respective drive wheel; and

a controller responsive to signals generated by the bumper sensor and the wheel drop sensors to redirect the robot in response to a signal from one of the bumper sensor and at least one of the wheel drop sensors.

20. The robot according to claim 19, further comprising an obstacle sensor in a forward portion of the robot responsive to obstacles encountered by the robot, the obstacle sensor further comprising an emitter and a detector configured to detect a proximity of an object and transmit a detection signal that causes the motor drive to reduce the speed of the robot.

21. The robot according to claim 19, wherein the controller is configured to initiate a collision avoidance routine that navigates the robot about objects as the robot moves across the floor surface.

22. The robot of claim 19, wherein the at least three cliff sensors are substantially evenly distributed along the arc defined by the arcuate forward portion of the robot housing.

23. The robot of claim 19, further comprising an edge cleaner, the edge cleaner comprising:

a motor;

a shaft mounted in a recess in an underside of the robot housing and rotatable with the motor; and

a side brush comprising at least two arms extending outwardly from the shaft and attached to the shaft such that rotation of the shaft causes the side brush to move debris from the floor surface beyond a peripheral edge of the robot housing for collection by the robot.

24. The robot of claim 19, wherein the wheel drop sensor sends a signal causing the motor drive to redirect the robot when the wheel moves downwardly by a predetermined amount.

25. The robot of claim 23, wherein the at least two arms of the side brush are curvilinear in order to facilitate the movement of debris in a direction under the robot housing.

26. The robot of claim 19, wherein at least one of the three cliff sensors is disposed adjacent a mid-point of the arcuate forward edge.

27. The robot of claim 19, wherein the wheel drop sensor senses when the respective drive wheel pivots downwardly.

28. The robot of claim 19, wherein the wheel drop sensor senses when the respective drive wheel extends downwardly.

29. The robot of claim 23, wherein the at least two arms of the side brush periodically during a duration of time intersect a path between at least one of the three cliff sensors and the floor surface as the robot is moved across the floor surface.