Lawn care robot

• US 8,954,193 B2
• Filed: 12/12/2013
• Issued: 02/10/2015
• Est. Priority Date: 03/17/2006
• Status: Expired due to Fees

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Sandin, Paul E., Jones, Joseph L., Ozick, Daniel N., Cohen, David A., Lewis, David M. Jr., Vu, Clara, Dubrovsky, Zivthan A., Preneta, Joshua B., Mammen, Jeffrey W., Gilbert, Duane L., Campbell, Tony L., Bergman, John
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): LI, CE LI
• Application Number:
  US14/104,390
• Publication Number:
  US 20140095008A1
• Time in Patent Office: 425 Days
• Field of Search: 700/245, 700/250, 700253-255, 700257-259, 700/261, 701/23, 701 25- 27, 318/568.12, 318/568.16, 318/580, D15/14, 56/101, 56 102 A- 102 B, 56 102 D- 102 F, 56/102.R
• US Class Current: 700/258
• 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 body;

a drive system carried by the body and configured to maneuver the robot across a lawn;

a grass cutter carried by the body;

at least one obstacle sensor carried by the body, the at least one obstacle sensor configured to detect when the body encounters a surface phenomenon that may be treated as an obstacle; and

a kill switch in a manual handle configured to be attached to the body and in communication with the drive system, the kill switch configured to turn off the cutter when the kill switch is not manually depressed;

wherein the drive system is configured to operate in an autonomous mode when the manual handle is not attached to the body and redirect the robot away from detected obstacles, and

wherein the drive system is configured to operate in a manual mode when the kill switch is manually depressed.

2. The robot lawnmower of claim 1, wherein the drive system is configured to have a default kill switch off condition when the detachable handle is attached to the body and a default kill switch on condition when the detachable handle is detached from the body.

3. The robot lawnmower of claim 1, wherein the manual handle is configured in the form of a conventional push mower handle.

4. The robot lawnmower of claim 1, comprising a user interface configured to notify a user while in manual mode when obstacle sensor detects an obstacle.

5. The robot lawnmower of claim 1, where in the body is configured to receive and stow the detachable manual handle.

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

7. The robot lawnmower of claim 1, wherein the obstacle sensor comprises:

a tilt sensor carried by the body, the tilt sensor configured to monitor a robot tilt to provide terrain data to determine whether the body is maneuvering over surface phenomena that may be treated as obstacles,

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

a water content sensor configured to sense water content indicative of a non-grass surface below the body and detect surface obstacles indicated as water.

8. 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 body and differentially driven with respect to each other.