Lawn care robot

• US 10,037,038 B2
• Filed: 04/28/2015
• Issued: 07/31/2018
• Est. Priority Date: 03/17/2006
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Sandin, Paul E., Jones, Joseph L., Ozick, Daniel N., Cohen, David A., Lewis, Jr., David M., Vu, Clara, Dubrovsky, Zivthan A., Preneta, Joshua B., Mammen, Jeffrey W., Gilbert, Jr., Duane L., Campbell, Tony L., Bergman, John
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): Li, Ce Li
• Application Number:
  US14/698,461
• Publication Number:
  US 20150234385A1
• Time in Patent Office: 1,190 Days
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• CPC Class Codes: B60L 2200/40 Working vehicles
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/425 Temperature
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 2250/16 by display
• CPC Class Codes: B60L 2260/32 Auto pilot mode
• CPC Class Codes: B60L 2270/145 Structure borne vibrations
• CPC Class Codes: B60L 3/0023 Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 50/52 characterised by DC-motors
• CPC Class Codes: B60L 50/62 charged by low-power generators primarily intended to support the batteries, e.g. range extenders
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: G05D 1/0225 involving docking at a fixed facility, e.g. base station or loading bay parking aids B62D15/027
• 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 1/0259 using magnetic or electromagnetic means
• CPC Class Codes: G05D 1/0261 using magnetic plots
• CPC Class Codes: G05D 1/0265 : using buried wires
• CPC Class Codes: G05D 1/028 : using a RF signal
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y10S 901/01 : Mobile robot
• CPC Class Codes: Y10S 901/09 : Closed loop, sensor feedback controls arm movement

Abstract

A robot lawnmower includes a body and a drive system carried by the body and configured to maneuver the robot across a lawn. The robot also includes a grass cutter and a swath edge detector, both carried by the body. The swath edge detector is configured to detect a swath edge between cut and uncut grass while the drive system maneuvers the robot across the lawn while following a detected swath edge. The swath edge detector includes a calibrator that monitors uncut grass for calibration of the swath edge detector. In some examples, the calibrator comprises a second swath edge detector.

Claims

1. A robot lawnmower comprising:

a drive system configured to maneuver the robot lawnmower across a lawn;

a controller in communication with the drive system;

a grass cutter;

at least one obstacle sensor in communication with the controller and configured to detect surface phenomena indicating potential obstacles;

a boundary responder detection system including a receiver unit configured to receive signals from active boundary responders;

wherein the controller is configured to;

operate in a check setup mode in which a user maneuvers the robot lawnmower to circumnavigate and approach a boundary and obstacles while the robot lawnmower is in manual mode, and to

permit operation of the robot lawnmower in an autonomous mode in which the controller determines a location of the robot lawnmower based at least in part on a time-of-flight from one or more of the active boundary responders and only after the check setup mode is completed; and

a user interface configured to provide notification during the check setup mode when the robot lawnmower detects surface phenomena indicated as water content detected by a water content sensor, as surface phenomena detected by a tilt sensor, or as loss of wheel contact detected by a wheel drop sensor.

2. The robot lawnmower of claim 1, wherein the drive system is configured to direct the robot lawnmower at a faster speed during manual mode than in autonomous mode.

3. The robot lawnmower of claim 1, wherein the controller operating the drive system in the manual mode does not redirect the robot lawnmower in response to the obstacle sensor detecting an obstacle.

4. The robot lawnmower of claim 1, wherein the active boundary responders are configured to emit signals detectable by the boundary responder detection system.

5. The robot lawnmower of claim 1, wherein the obstacle sensor comprises one or more of:

the tilt sensor, in which the tilt sensor is configured to monitor a robot tilt to provide terrain data to determine whether the robot is maneuvering over surface phenomena indicative of potential obstacles,

the wheel drop sensor, in which the wheel drop sensor is configured to sense when at least a portion of the drive system enters an extended position indicative of loss of wheel contact with a surface of the lawn, or

the water content sensor, in which the water content sensor is configured to sense water content indicative of a non-grass surface below the robot lawnmower and detect surface obstacles indicated as water.

6. The robot lawnmower of claim 5, wherein the obstacle sensor comprises the wheel drop sensor.

7. The robot lawnmower of claim 5, wherein the obstacle sensor comprises the water content sensor.

8. The robot lawnmower of claim 1, wherein the boundary responder detection system is in communication with the controller, and the boundary responder detection system is configured to detect at least one of the active boundary responders.

9. The robot lawnmower of claim 8, wherein the controller operating the drive system in manual mode does not redirect the robot lawnmower in response to the boundary responder detection system detecting at least one of the active boundary responders.

10. The robot lawnmower of claim 8, wherein the user interface is configured to notify the user while in check setup mode when the robot lawnmower detects at least one of the active boundary responders.

11. The robot lawnmower of claim 1, wherein the drive system comprises right and left sets of forward and rear drive wheels, each set of drive wheels being disposed on a corresponding side of the lawnmower and differentially driven with respect to each other.

12. The robot lawnmower of claim 1, wherein the active boundary responders continuously or periodically emit a signal.

13. The robot lawnmower of claim 1, wherein the active boundary responders emit a radio-frequency, electro-magnetic wave, or an acoustic signal.

14. The robot lawnmower of claim 1, wherein the active boundary responders are only powered when the robot lawnmower is within a certain range of the active boundary responders.

15. The robot lawnmower of claim 1, wherein the robot lawnmower also determines the location of the robot lawnmower based on the determination of an additional robot positioning system.

16. The robot lawnmower of claim 1, wherein the robot lawnmower is configured to resolve a time of flight from a home base.

17. The robot lawnmower of claim 16, wherein the home base comprises a battery charging device.

18. The robot lawnmower of claim 17, wherein the controller is configured to permit operation of the robot lawnmower in the autonomous mode only after the robot lawnmower has exceeded moving a certain distance in the check setup mode.

19. A robot lawnmower comprising:

a drive system configured to maneuver the robot lawnmower across a lawn;

a controller in communication with the drive system;

a grass cutter;

at least one obstacle sensor in communication with the controller and configured to detect surface phenomena indicating potential obstacles;

a boundary responder detection system including a receiver unit configured to receive signals from active boundary responders; and

a user interface;

wherein the robot lawnmower is configured to operate in a check setup mode during a first time period and operate in an autonomous mode during a second time period after the robot lawnmower has exceeded moving a certain distance in the check setup mode;

wherein when the robot lawnmower is operating in the check setup mode, a user manually maneuvers the robot lawnmower to circumnavigate and approach a boundary and obstacles, and the user interface is configured to provide notification when the robot lawnmower detects surface phenomena indicated by the at least one obstacle sensor;

wherein when the robot lawnmower is operating in the autonomous mode, the controller determines a location of the robot lawnmower based at least in part on a time-of-flight from one or more of the active boundary responders.

20. The robot lawnmower of claim 19, wherein the controller is configured to permit operation of the robot lawnmower in the autonomous mode only after the robot lawnmower has exceeded moving a certain distance in the check setup mode.

21. The robot lawnmower of claim 19, wherein the controller operating the drive system in the manual mode does not redirect the robot lawnmower in response to the obstacle sensor detecting an obstacle.

22. The robot lawnmower of claim 19, wherein the obstacle sensor comprises one or more of:

the tilt sensor, in which the tilt sensor is configured to monitor a robot tilt to provide terrain data to determine whether the lawnmower is maneuvering over surface phenomena indicative of potential obstacles,

the wheel drop sensor, in which the wheel drop sensor is configured to sense when at least a portion of the drive system enters an extended position indicative of loss of wheel contact with a surface of the lawn, or

the water content sensor, in which the water content sensor is configured to sense water content indicative of a non-grass surface below the lawnmower and detect surface obstacles indicated as water.