Method and system for multi-mode coverage for an autonomous robot

• US 8,838,274 B2
• Filed: 06/30/2010
• Issued: 09/16/2014
• Est. Priority Date: 06/12/2001
• Status: Expired due to Fees

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Jones, Joseph L., Mass, Philip R.
• Primary Examiner(s): BEHNCKE, CHRISTINE M
• Application Number:
  US12/826,909
• Publication Number:
  US 20100263142A1
• Time in Patent Office: 1,539 Days
• Field of Search: 700/245, 700/253, 700/255, 700/250, 318/568.12, 318/568.13, 318/568.17, 134/18
• US Class Current: 700/253
• CPC Class Codes: A47L 11/00 Machines for cleaning floors, carpets, furniture, walls, or wall coverings
• CPC Class Codes: B25J 11/0085 Cleaning
• CPC Class Codes: B25J 9/1694 characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception control, multi-sensor controlled systems, sensor fusion
• CPC Class Codes: G05D 1/0219 ensuring the processing of the whole working surface
• CPC Class Codes: G05D 1/0227 using mechanical sensing means, e.g. for sensing treated area
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: Y10S 901/01 Mobile robot

Abstract

A mobile robot operable to move on a surface in a room is provided. The mobile robot includes a shell and a chassis including at least two wheels. At least one motor is connected to the wheels for moving the mobile robot on the surface. A cleaner is operable to clean the surface as the mobile robot moves on the surface. A wall sensor is operable to detect a wall in the room as the mobile robot moves on the surface. A controller is operable to control the motor to move the mobile robot on the surface in accordance with a wall following mode and a bounce mode. In the wall following mode, the mobile robot moves generally adjacent to and along the wall in response to detection of the wall by the wall sensor. In the bounce mode, the mobile robot moves away from the wall.

Claims

1. A mobile robot operable to move on a surface in a room, the mobile robot comprising:

a shell;

a chassis including at least two wheels;

at least one motor connected to the at least two wheels for moving the mobile robot on the surface;

a controller operable to control the at least one motor to move the mobile robot on the surface in accordance with a first mode and a second mode;

a cleaner operable to clean the surface as the mobile robot moves on the surface;

a forward obstacle sensor approximately as wide as the shell and operable to detect obstacles forward of the shell along a direction of travel; and

a following sensor directed at a lateral position outside the shell and forward of the wheels, and operable to detect a wall in the room as the mobile robot moves on the surface,

wherein, in the first mode, the mobile robot moves generally adjacent to and along a portion of the wall in response to detection of the wall by the following sensor, the portion of the wall comprising at least one of an inside corner defining an angle less than 180° and

an outside corner defining an angle between 180° and

360°

,

wherein to negotiate the inside corner, the controller is operable to control the mobile robot according to a corner-handling routine comprising;

detecting a forward obstacle by the forward obstacle sensor,

turning the mobile robot in place to scan the following sensor away from a followed obstacle;

while turning, with the following sensor, losing detection of the followed obstacle, acquiring detection of the forward obstacle, and subsequently losing detection of the forward obstacle, and

in response to the following sensor losing detection of the forward obstacle, ceasing the turning of the mobile robot;

in the second mode, the mobile robot moves away from the wall, and

the controller is operable to control the mobile robot to move in accordance with the second mode after controlling the mobile robot to move in accordance with the first mode for a distance.

2. The mobile robot according to claim 1, wherein the controller is operable to control the mobile robot to move in accordance with the second mode after controlling the mobile robot to move in accordance with the first mode for the distance and encountering an obstacle.

3. The mobile robot according to claim 1, wherein the controller is further operable to control the mobile robot to change directions on the surface in accordance with one of predetermined times and random times during the second mode.

4. The mobile robot according to claim 3, wherein the controller is operable to control the mobile robot to move in accordance with the second mode until a number of second interactions is reached.

5. The mobile robot according to claim 3, wherein the controller is operable to control the mobile robot to cycle between the first mode and the second mode.

6. The mobile robot according to claim 1, wherein the controller is further operable to control the mobile robot to move in accordance with a spot cleaning mode in which the mobile robot moves only within a predetermined area of the room.

7. The mobile robot according to claim 6, wherein, in the spot cleaning mode, the mobile robot moves from a center of the predetermined area to a periphery of the predetermined area by successively moving around the center in increasing paths.

8. The mobile robot according to claim 7, further comprising:

a side brush disposed on a brush side of the mobile robot,

wherein, in the spot cleaning mode, the mobile robot moves around the center of the predetermined area with the brush side toward the periphery of the predetermined area.

9. The mobile robot according to claim 7, further comprising:

a side brush disposed on a brush side of the mobile robot,

wherein, in the spot cleaning mode, the mobile robot moves around the center of the predetermined area with the brush side toward the center of the predetermined area.

10. The mobile robot according to claim 1, further comprising:

wherein the controller is further operable to control the mobile robot to move in accordance with an obstacle mode in which the mobile robot moves to avoid physically contacting the obstacle in response to detection of the presence of the obstacle.

11. The mobile robot according to claim 10, wherein, in the obstacle mode, the mobile robot moves generally adjacent to and along a periphery of the obstacle.

12. The mobile robot according to claim 1, further comprising:

a cliff sensor operable to detect a cliff in the room,

wherein the controller is further operable to control the mobile robot to move in accordance with a cliff mode in which the mobile robot moves away from the cliff in response to detection of the cliff by the cliff sensor.

13. The mobile robot according to claim 1, wherein detecting a forward obstacle by the obstacle sensor comprises detecting contact between the robot and the forward obstacle.

14. The mobile robot according to claim 1, wherein turning the mobile robot in place comprises turning the mobile robot through at least a minimum angle based on an angle-of-encounter between the forward obstacle and the mobile robot.

15. The mobile robot according to claim 14, wherein the minimum angle is at least one of 14°

and 20°

.

16. The mobile robot according to claim 1, wherein turning the mobile robot in place comprises turning the mobile robot through at most a maximum angle based on an angle-of-encounter between the forward obstacle and the mobile robot.

17. The mobile robot according to claim 16, wherein the maximum angle is at least one of 19°

and 44°

.

18. The mobile robot according to claim 1, wherein the corner-handling routine further comprises:

after the turning has ceased, controlling the mobile robot to move generally adjacent to and along a portion of the forward obstacle.

19. A mobile robot operable to move on a surface in a room, the mobile robot comprising:

a shell;

a chassis including at least two wheels;

at least one motor connected to the at least two wheels for moving the mobile robot on the surface;

a controller operable to control the at least one motor to move the mobile robot on the surface in accordance with a plurality of modes;

a cleaner operable to clean the surface as the mobile robot moves on the surface;

a following sensor directed at a lateral position outside the shell and forward of the wheels, and operable to detect a wall in the room as the mobile robot moves on the surface;

a cliff sensor operable to detect a cliff in the room as the mobile robot moves on the surface; and

a forward obstacle sensor approximately as wide as the shell and operable to detect obstacles forward of the shell along a direction of travel,

wherein the controller is operable to control the mobile robot to move in accordance with one of the plurality of modes after controlling the mobile robot to move generally adjacent to and along a portion of the wall including at least one of an inside corner defining an angle less than 180° and

an outside corner defining an angle between 180° and

360°

; and

wherein to negotiate the inside corner, the controller is operable to control the mobile robot according to a corner-handling routine comprising;

detecting a forward obstacle by the forward obstacle sensor, turning the mobile robot in place to scan the following sensor away from a followed obstacle;

while turning, with the following sensor, losing detection of the followed obstacle, acquiring detection of the forward obstacle, and subsequently losing detection of the forward obstacle, and

in response to the following sensor losing detection of the forward obstacle, ceasing the turning of the mobile robot.

20. The mobile robot according to claim 19, wherein the controller is operable to control the mobile robot to move in accordance with the plurality of modes in response to detection of the wall by the following sensor, detection of the cliff by the cliff sensor, and detection of the presence of the obstacle by the obstacle sensor.

21. The mobile robot according to claim 19, wherein the plurality of modes includes a wall following mode in which the mobile robot moves generally adjacent to and along the wall in response to detection of the wall by the following sensor.

22. The mobile robot according to claim 21, wherein the plurality of modes includes a bounce mode in which the mobile robot moves away from the wall after the mobile robot moves in accordance with the wall following mode for one of a predetermined time and distance.

23. The mobile robot according to claim 22, wherein the controller is operable to control the mobile robot to change directions on the surface in accordance with one of predetermined times and random times during the bounce mode.

24. The mobile robot according to claim 23, wherein the controller is operable to control the mobile robot to cycle between the wall following mode and the bounce mode.

25. The mobile robot according to claim 19, wherein the plurality of modes includes a spot cleaning mode in which the mobile robot moves only within a predetermined area of the room from a center of the predetermined area to a periphery of the predetermined area by successively moving around the center in increasing paths.

26. The mobile robot according to claim 19, wherein the plurality of modes includes an obstacle mode in which the mobile robot moves to avoid physically contacting the obstacle in response to detection of the presence of the obstacle by the obstacle sensor.

27. The mobile robot according to claim 26, wherein, in the obstacle mode, the mobile robot moves generally adjacent to and along a periphery of the obstacle.

28. The mobile robot according to claim 19, wherein the plurality of modes includes a cliff mode in which the mobile robot moves away from the cliff in response to detection of the cliff by the cliff sensor.

29. The mobile robot according to claim 19, wherein detecting a forward obstacle by the obstacle sensor comprises detecting contact between the robot and the forward obstacle.

30. The mobile robot according to claim 19, wherein turning the mobile robot in place comprises turning the mobile robot through at least a minimum angle based on an angle-of-encounter between the forward obstacle and the mobile robot.

31. The mobile robot according to claim 30, wherein the minimum angle is at least one of 14°

and 20°

.

32. The mobile robot according to claim 19, wherein turning the mobile robot in place comprises turning the mobile robot through at most a maximum angle based on an angle-of-encounter between the forward obstacle and the mobile robot.

33. The mobile robot according to claim 32, wherein the maximum angle is at least one of 19°

and 44°

.

34. The mobile robot according to claim 19, wherein the corner-handling routine further comprises:

after the turning has ceased, controlling the mobile robot to move generally adjacent to and along a portion of the forward obstacle.