Robotic lawn mowing boundary determination

• US 10,750,667 B2
• Filed: 12/21/2017
• Issued: 08/25/2020
• Est. Priority Date: 10/10/2014
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Yamauchi, Brian, Beaulieu, Andrew, Balutis, Paul C.
• Primary Examiner(s): Camby, Richard M
• Application Number:
  US15/850,413
• Publication Number:
  US 20180168097A1
• Time in Patent Office: 978 Days
• Field of Search: None
• CPC Class Codes: A01B 69/008 automatic
• CPC Class Codes: A01D 2101/00 Lawn-mowers
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• CPC Class Codes: G05D 1/0212 with means for defining a desired trajectory involving a plurality of land vehicles G05D1/0287
• CPC Class Codes: G05D 1/0219 ensuring the processing of the whole working surface
• CPC Class Codes: G05D 1/0221 involving a learning process
• CPC Class Codes: G05D 1/0236 in combination with a laser lasers per se H01S
• CPC Class Codes: Y10S 901/01 Mobile robot

Abstract

A method of mowing an area with an autonomous mowing robot comprises storing, in non-transient memory of the robot, a set of geospatially referenced perimeter data corresponding to positions of the mowing robot as the mowing robot is guided about a perimeter of an area to be mowed, removing from the set of perimeter data one or more data points thereby creating a redacted data set and controlling the mowing robot to autonomously mow an area bounded by a boundary corresponding to the redacted data set, including altering direction of the mowing robot at or near a position corresponding to data in the redacted data set so as to redirect the robot back into the bounded area.

Claims

1. A mowing robot comprising:

a grass cutter;

a drive system including a motorized wheel; and

a controller operably coupled to the motorized wheel for maneuvering the mowing robot to traverse a lawn area, the controller configured to;

control the mowing robot to autonomously mow within an area bounded by a boundary at a first speed, and

control the mowing robot to autonomously mow at a second speed slower than the first speed when the mowing robot is within a predetermined distance to the boundary.

2. The mowing robot of claim 1, wherein the controller is configured to adjust a mowing direction of the mowing robot in response to reaching the boundary.

3. The mowing robot of claim 2, wherein the controller is configured to control the mowing robot to mow along the boundary at the second speed.

4. The mowing robot of claim 1, wherein the first speed is slower than a manual operating speed of the mowing robot, and the mowing robot is configured to operate at the manual operating speed in response to a detachable push bar being connected to the mowing robot.

5. The mowing robot of claim 1, wherein the controller is configured to cause the mowing robot to autonomously mow at the second speed when the mowing robot is within the predetermined distance to the boundary, until the mowing robot reaches the boundary.

6. The mowing robot of claim 1, wherein the controller is configured to identify the boundary from stored geospatially referenced perimeter coordinates determined in a teaching mode.

7. The mowing robot of claim 1, wherein the controller is configured to:

determine a second boundary that is at a predetermined distance from and inside the first boundary,

control the mowing robot to mow at the first speed when the robot is within an area bounded by the second boundary, and

control the mowing robot to mow at the second speed when the mowing robot is on the second boundary, or between the second boundary and the first boundary.

8. The mowing robot of claim 7, wherein the controller is configured to:

identify cells of a two-dimensional data array as corresponding to the positions of the mowing robot;

identify cells within the first boundary and within the predetermined distance of the first boundary; and

determine the second boundary based on the cells that are within the first boundary and within the predetermined distance of the first boundary.

9. The mowing robot of claim 1, wherein the controller is configured to apply a smoothing function to the second boundary to smooth the second boundary.

10. A method of mowing an area with an autonomous mowing robot, the method comprising:

maneuvering, using a drive system including a motorized wheel, the mowing robot to traverse a lawn area;

controlling, using a controller operably coupled to the drive system, the mowing robot to autonomously mow within an area bounded by a predetermined boundary at a first speed; and

controlling, using the controller, the mowing robot to autonomously mow at a second speed slower than the first speed when the mowing robot is within a predetermined distance to the predetermined boundary.

11. The method of claim 10, comprising storing, in non-transient memory of the robot, a set of geospatially referenced perimeter data corresponding to positions of the mowing robot as the mowing robot is guided about a perimeter of an area to be mowed.

12. The method of claim 11, comprising determining, at the controller, the boundary based on at least a portion of the stored set of geospatially referenced perimeter data.

13. The method of claim 10, comprising:

determining a second boundary that is at a predetermined distance from and inside the predetermined boundary,

controlling the mowing robot to mow at the first speed when the robot is within an area bounded by the second boundary, and

controlling the mowing robot to mow at the second speed when the mowing robot is on the second boundary, or between the second boundary and the predetermined boundary.

14. The method of claim 13, comprising:

identifying cells of a two-dimensional data array as corresponding to the positions of the mowing robot;

identifying cells that are within the predetermined boundary and within the predetermined distance of the predetermined boundary; and

determining the second boundary based on the cells that are within the predetermined boundary and within the predetermined distance of the predetermined boundary.