US6809490B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for multi-mode coverage for an autonomous robot
Assignee: iRobot Corp
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Filing: 2002-06-12
•
Granted: 2004-10-26
•
Expires: 2022-06-12
Abstract
Abstract A control system for a mobile robot (10) is provided to effectively cover a given area by operating in a plurality of modes, including an obstacle following mode (51) and a random bounce mode (49). In other embodiments, spot coverage, such as spiraling (45), or other modes are also used to increase effectiveness. In addition, a behavior based architecture is used to implement the control system, and various escape behaviors are used to ensure full coverage.
Inventors
- 👤 Joseph L. Jones
- 👤 Philip R. Mass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:02
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/02; G05D1/021; G05D1/0268; G05D1/0272; G05D1/0212; G05D1/0219; G05D1/0227; G05D1/0231; G05D1/0238; G05D1/0242
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
148 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; (c) and a control system operatively connected to said obstacle detection sensor and said means for moving; (d) said control system configured to operate the robot in a plurality of operational modes and to select from among the plurality of modes in real time in response to signals generated by the obstacle detection sensor, said plurality of operational modes comprising: a spot-coverage mode whereby the robot operates in an isolated area, an obstacle following mode whereby said robot travels adjacent to an obstacle, and a bounce mode whereby the robot travels substantially in a direction away from an obstacle after encountering the obstacle, and wherein, when in the obstacle following mode, the robot travels adjacent to an obstacle for a distance at least twice the work width of the robot.
Claim 2
Dependent Claim
148 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; (c) and a control system operatively connected to said obstacle detection sensor and said means for moving; (d) said control system configured to operate the robot in a plurality of operational modes and to select from among the plurality of modes in real time in response to signals generated by the obstacle detection sensor, said plurality of operational modes comprising: a spot-coverage mode whereby the robot operates in an isolated area, an obstacle following mode whereby said robot travels adjacent to an obstacle, and a bounce mode whereby the robot travels substantially in a direction away from an obstacle after encountering the obstacle, and wherein, when in the obstacle following mode, the robot travels adjacent to an obstacle for a distance at least twice the work width of the robot.
Claim 3
Dependent Claim
33 words
A mobile robot according to claim 1 in which said control system is configured to operate first in said spot-coverage mode, then alternate operation between said obstacle following mode and said bounce mode.
Claim 4
Dependent Claim
16 words
A mobile robot according to claim 2 in which said spot-coverage mode comprises substantially spiral movement.
Claim 5
Dependent Claim
25 words
A mobile robot according to claim 2 in which the control system is configured to return to said spot-coverage mode after a predetermined traveling distance.
Claim 6
Dependent Claim
25 words
A mobile robot according to claim 2 in which the control system is configured to return to said spot-coverage mode after a predetermined elapsed time.
Claim 7
Dependent Claim
32 words
A mobile robot according to claim 2 in which the control system is configured to return to said spot-coverage mode if the average distance between obstacle interactions is above a predetermined threshold.
Claim 8
Dependent Claim
17 words
A mobile robot according to claim 1 , whereby said obstacle detection sensor comprises a tactile sensor.
Claim 9
Dependent Claim
18 words
A mobile robot according to claim 7 , whereby said obstacle detection sensor further comprises an IR sensor.
Claim 10
Dependent Claim
78 words
The mobile robot according to claim 1 , whereby said obstacle following mode comprises alternating between decreasing the turning radius of the robot as a function of distance traveled such that the robot turns towards the obstacle until the obstacle detection sensor detects the obstacle, and decreasing the turning radius of the robot as a function of distance traveled such that the robot turns away from the obstacle until the obstacle detection system no longer detects the obstacle.
Claim 11
Dependent Claim
41 words
The mobile robot according to claim 1 , whereby the robot operates in said obstacle following mode for a distance greater than twice the work width of the robot and less than approximately ten times the work width of the robot.
Claim 12
Dependent Claim
40 words
The mobile robot according to claim 10 , whereby the robot operates in said obstacle following mode for a distance greater than twice the work width of the robot and less than five times the work width of the robot.
Claim 13
Dependent Claim
18 words
The mobile robot according to claim 1 , further comprising a means for manually selecting an operational mode.
Claim 14
Dependent Claim
143 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; (c) and a control system operatively connected to said obstacle detection sensor and said means for moving; (d) said control system configured to operate the robot in a plurality of operational modes and to select from among the plurality of modes in real time in response to signals generated by the obstacle detection sensor, said plurality of operational modes comprising: an obstacle following mode whereby said robot travels adjacent to an obstacle for a distance at least twice the work width of the robot and a bounce mode whereby the robot travels substantially in a direction away from an obstacle after encountering the obstacle; (e) whereby said control system is configured to alternate into said obstacle following mode after a predetermined number of sensor interactions.
Claim 15
Dependent Claim
143 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; (c) and a control system operatively connected to said obstacle detection sensor and said means for moving; (d) said control system configured to operate the robot in a plurality of operational modes and to select from among the plurality of modes in real time in response to signals generated by the obstacle detection sensor, said plurality of operational modes comprising: an obstacle following mode whereby said robot travels adjacent to an obstacle for a distance at least twice the work width of the robot and a bounce mode whereby the robot travels substantially in a direction away from an obstacle after encountering the obstacle; (e) whereby said control system is configured to alternate into said obstacle following mode after a predetermined number of sensor interactions.
Claim 16
Dependent Claim
18 words
A mobile robot according to claim 13 , wherein said predetermined number of sensor interactions is randomly determined.
Claim 17
Dependent Claim
22 words
A mobile robot according to claim 13 , wherein said predetermined number of sensor interactions is between approximately 5 and approximately 15.
Claim 18
Dependent Claim
32 words
A mobile robot according to claim 13 , wherein said control system is configured to alternate into said bounce mode after the robot travels a predetermined distance in said obstacle following mode.
Claim 19
Dependent Claim
43 words
A mobile robot according to claim 13 , wherein said control system is configured to alternate into said bounce mode upon either the robot has traveled a maximum distance or the robot has traveled a minimum distance and an obstacle has been encountered.
Claim 20
Dependent Claim
17 words
A mobile robot according to claim 17 , wherein said minimum distance is at least 115 cm.
Claim 21
Dependent Claim
17 words
A mobile robot according to claim 18 , wherein said maximum distance is less than 520 cm.
Claim 22
Dependent Claim
23 words
A mobile robot according to claim 13 , wherein the control system alternates operational modes based on the distance traveled by said robot.
Claim 23
Dependent Claim
130 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; (c) a control system operatively connected to said obstacle detection sensor and said robot moving means; and wherein (d) said control system is configured to operate the robot in a plurality of operational modes, said plurality of operational modes including an obstacle following mode wherein the robot travels adjacent to an obstacle, and a bounce mode wherein the robot travels substantially in a direction away from an obstacle after encountering the obstacle; (e) said control system being further configured to alternate into said obstacle following mode after a predetermined number of sensor interactions; and (f) a means for determining a level of clutter associated with the surface over which the robot moves.
Claim 24
Dependent Claim
130 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; (c) a control system operatively connected to said obstacle detection sensor and said robot moving means; and wherein (d) said control system is configured to operate the robot in a plurality of operational modes, said plurality of operational modes including an obstacle following mode wherein the robot travels adjacent to an obstacle, and a bounce mode wherein the robot travels substantially in a direction away from an obstacle after encountering the obstacle; (e) said control system being further configured to alternate into said obstacle following mode after a predetermined number of sensor interactions; and (f) a means for determining a level of clutter associated with the surface over which the robot moves.
Claim 25
Dependent Claim
27 words
A mobile robot according to claim 21 , wherein said means for determining the level of clutter comprises tracking the number of interactions with obstacles over time.
Claim 26
Dependent Claim
38 words
A mobile robot according to claim 22 , further comprising a means for imputing the approximate area of the surface, wherein said means for determining the level of clutter further relates to the approximate area of the surface.
Claim 27
Dependent Claim
25 words
A mobile robot according to claim 22 , wherein the level of clutter is correlated to the frequency at which the controller alternates operational modes.
Claim 28
Dependent Claim
22 words
A mobile robot according to claim 21 , wherein the level of clutter is positively correlated to a minimum obstacle following distance.
Claim 29
Dependent Claim
131 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; and (c) a control system operatively connected to said obstacle detection sensor and said robot moving means; and wherein (d) said control system is configured to operate the robot in a plurality of operational modes, said plurality of operational modes including an obstacle following mode wherein the robot travels adjacent to an obstacle, and a bounce mode wherein the robot travels substantially in a direction away from an obstacle after encountering the obstacle; (e) said control system being further configured to alternate into said obstacle following mode after a predetermined number of sensor interactions; and further (f) wherein the control system alternates between said operational modes based upon a lack of sensor input.
Claim 30
Dependent Claim
131 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; and (c) a control system operatively connected to said obstacle detection sensor and said robot moving means; and wherein (d) said control system is configured to operate the robot in a plurality of operational modes, said plurality of operational modes including an obstacle following mode wherein the robot travels adjacent to an obstacle, and a bounce mode wherein the robot travels substantially in a direction away from an obstacle after encountering the obstacle; (e) said control system being further configured to alternate into said obstacle following mode after a predetermined number of sensor interactions; and further (f) wherein the control system alternates between said operational modes based upon a lack of sensor input.
Claim 31
Dependent Claim
46 words
A mobile robot according to claim 1 , wherein said control system further comprises memory wherein an operational system program is stored, said operational system program comprising a plurality of behaviors and an arbiter to select which behavior is given control over the means for moving.
Claim 32
Dependent Claim
13 words
A mobile robot according to claim 27 , further comprising an escape behavior.
Claim 33
Dependent Claim
29 words
A mobile robot according to claim 28 , wherein said obstacle detection sensor comprises a tactile sensor, and wherein said escape behavior comprises operating in said obstacle following mode.
Claim 34
Dependent Claim
22 words
A mobile robot according to claim 28 , wherein said escape behavior is triggered by the rate of a motor stall event.
Claim 35
Dependent Claim
25 words
A mobile robot according to claim 30 , wherein said escape behavior is triggered by an increase in said rate of a motor stall event.
Claim 36
Dependent Claim
20 words
A mobile robot according to claim 28 , wherein said escape behavior is triggered by the duration of sensor input.
Claim 37
Dependent Claim
17 words
A mobile robot according to claim 28 , wherein said escape behavior comprises shutting off the robot.
Claim 38
Dependent Claim
20 words
A mobile robot according to claim 28 , wherein said escape behavior is triggered by a lack of sensor input.
Claim 39
Dependent Claim
29 words
A mobile robot according to claim 13 , further comprising a cliff detector, whereby said control system is configured to reduce the robot's velocity upon detection of a cliff.
Claim 40
Dependent Claim
132 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; (c) and a control system operatively connected to said obstacle detection sensor and said means for moving; (d) said control system configured to operate the robot in a plurality of modes, said plurality of modes comprising: an obstacle following mode whereby said robot travels adjacent to an obstacle, and a bounce mode whereby the robot travels substantially in a direction away from an obstacle after encountering the obstacle; (e) whereby said control system is configured to alternate into said obstacle following mode after a predetermined number of sensor interactions, and further comprising: (f) a wheel drop sensor, whereby said robot utilizes the rate of wheel drop sensor events as input to said control system.
Claim 41
Dependent Claim
132 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; (c) and a control system operatively connected to said obstacle detection sensor and said means for moving; (d) said control system configured to operate the robot in a plurality of modes, said plurality of modes comprising: an obstacle following mode whereby said robot travels adjacent to an obstacle, and a bounce mode whereby the robot travels substantially in a direction away from an obstacle after encountering the obstacle; (e) whereby said control system is configured to alternate into said obstacle following mode after a predetermined number of sensor interactions, and further comprising: (f) a wheel drop sensor, whereby said robot utilizes the rate of wheel drop sensor events as input to said control system.
Claim 42
Independent Claim
135 words
A method of controlling a mobile-robot equipped with a sensor for detecting an obstacle, said method comprising the steps of: a. moving in a spiral running motion; b. discontinuing said spiral running motion after the earlier of sensing an obstacle or traveling a predetermined distance; c. running in a substantially forward direction until an obstacle is detected; d. turning and running along the detected obstacle for a distance at least twice the work width of the robot; e. turning away from the detected obstacle and running in a substantially forward direction; and f. thereafter repeating said step of running along a detected obstacle and said step of turning away from the detected obstacle, wherein changes in movement are selected in real time in response to any of calculated distance or signals generated by the sensor.
Claim 43
Independent Claim
135 words
A method of controlling a mobile-robot equipped with a sensor for detecting an obstacle, said method comprising the steps of: a. moving in a spiral running motion; b. discontinuing said spiral running motion after the earlier of sensing an obstacle or traveling a predetermined distance; c. running in a substantially forward direction until an obstacle is detected; d. turning and running along the detected obstacle for a distance at least twice the work width of the robot; e. turning away from the detected obstacle and running in a substantially forward direction; and f. thereafter repeating said step of running along a detected obstacle and said step of turning away from the detected obstacle, wherein changes in movement are selected in real time in response to any of calculated distance or signals generated by the sensor.
Claim 44
Dependent Claim
26 words
The mobile-robot steering method according to claim 37 , further comprising the step of repeating the spiral running motion after a predetermined number of sensor events.
Claim 45
Dependent Claim
28 words
The mobile-robot steering method according to claim 37 , whereby the robot runs along said obstacle for at least a minimum distance but less than a maximum distance.
Claim 46
Dependent Claim
22 words
The mobile-robot steering method according to claim 39 , whereby said obstacle sensor comprises an IR sensor able to detect said boundary.
Claim 47
Dependent Claim
18 words
The mobile-robot steering method according to claim 40 , whereby said obstacle sensor further comprises a tactile sensor.
Claim 48
Dependent Claim
118 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; (c) a cliff sensor; and (d) a control system operatively connected to said obstacle detection sensor, said cliff sensor, and said means for moving; (e) said control system configured to operate the robot in a plurality of operational modes, said plurality of operational modes comprising: a spot-coverage mode whereby the robot operates in an isolated area, an obstacle following mode whereby said robot travels adjacent to an obstacle for a distance at least twice the work width of the robot, and a bounce mode whereby the robot travels substantially in a direction away from an obstacle after encountering the obstacle.
Claim 49
Dependent Claim
118 words
A mobile robot comprising: (a) means for moving the robot over a surface; (b) an obstacle detection sensor; (c) a cliff sensor; and (d) a control system operatively connected to said obstacle detection sensor, said cliff sensor, and said means for moving; (e) said control system configured to operate the robot in a plurality of operational modes, said plurality of operational modes comprising: a spot-coverage mode whereby the robot operates in an isolated area, an obstacle following mode whereby said robot travels adjacent to an obstacle for a distance at least twice the work width of the robot, and a bounce mode whereby the robot travels substantially in a direction away from an obstacle after encountering the obstacle.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2007-10-26 | 2008-04-26 | 2008-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-10-26 | 2012-04-26 | 2012-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-10-26 | 2016-04-26 | 2016-10-26 | $7700.00 | Window Closed / Lapsed |