Autonomous lawnmower using laser scanner

• US 10,561,063 B2
• Filed: 01/10/2018
• Issued: 02/18/2020
• Est. Priority Date: 01/10/2018
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Hasegawa, Toshiyuki, Wians, Jeffrey Allen
• Primary Examiner(s): Torres, Alicia
• Application Number:
  US15/867,386
• Publication Number:
  US 20190208699A1
• Time in Patent Office: 769 Days
• CPC Class Codes: A01B 69/008 automatic
• CPC Class Codes: A01D 2101/00 Lawn-mowers
• CPC Class Codes: A01D 34/006 Control or measuring arrangements
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• CPC Class Codes: A01D 34/64 mounted on a vehicle, e.g. a tractor, or drawn by an animal or a vehicle A01D34/695 takes precedence
• CPC Class Codes: A01D 69/02 electric
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01S 7/4808 Evaluating distance, position or velocity data
• CPC Class Codes: G05D 1/0011 associated with a remote control arrangement
• CPC Class Codes: G05D 1/0061 for transition from automatic pilot to manual pilot and vice versa
• CPC Class Codes: G05D 1/0088 characterized by the autonomous decision making process, e.g. artificial intelligence, predefined behaviours using knowledge based models G06N5/00
• CPC Class Codes: G05D 1/0214 in accordance with safety or protection criteria, e.g. avoiding hazardous areas monitoring the location of vehicles within a certain area, e.g. forbidden or allowed areas, in traffic control systems for road vehicles G08G1/13
• CPC Class Codes: G05D 1/0219 ensuring the processing of the whole working surface
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means

Abstract

A lawnmower includes a cutting blade, a laser scanner rotatably mounted above the cutting blade, a first motor rotatably driving the laser scanner, and a processor communicatively coupled to the laser scanner. The processor may obtain laser scanner measurements of a plurality of angles around the lawnmower, each laser scanner measurement including a distance and a received signal strength. The processor may classify a surface at each of the angles based on the distance and the received signal strength. The processor may determine a navigation path of the lawnmower based on the classification of the surface at each of the angles. The lawnmower may also include a second motor operably coupled to one or more drive wheels. The processor may control the second motor to move the lawnmower along the navigation path.

Claims

1. A lawnmower, comprising:

a cutting blade;

a laser scanner rotatably mounted above the cutting blade;

a first motor rotatably driving the laser scanner; and

a processor communicatively coupled to the laser scanner and configured to;

obtain laser scanner measurements of a plurality of angles around the lawnmower, each laser scanner measurement including a distance and a received signal strength;

classify a surface at each of the angles based on the distance and the received signal strength; and

determine a navigation path of the lawnmower based on the classification of the surface at each of the angles.

2. The lawnmower of claim 1, further comprising a second motor operably coupled to one or more drive wheels, wherein the processor is configured to control the second motor to move the lawnmower along the navigation path.

3. The lawnmower of claim 1, further comprising a wireless receiver that receives a manual override signal from a remote control, wherein the processor controls the lawnmower according to the manual override signal instead of the navigation path.

4. The lawnmower of claim 1, wherein the processor is configured to classify a surface having a signal strength above a threshold as grass.

5. The lawnmower of claim 1, wherein the laser scanner is oriented at a downward angle, wherein the processor classifies the surface at each of the angles by comparing the distance to an object detection threshold and a grass detection threshold.

6. The lawnmower of claim 5, wherein the processor classifies the surface at one or more of the angles as tall grass to be mowed when the distance is between the object detection threshold and the grass detection threshold.

7. The lawnmower of claim 6, wherein the processor determines the navigation path to turn the lawnmower toward the angle where the surface is classified as tall grass in response to classifying a surface in a forward direction as either an object or a lower surface.

8. The lawnmower of claim 1, wherein the processor is configured to:

detect an object based on a signal strength less than a threshold strength and a detected distance less than a threshold distance; and

determine the navigation path to avoid the object.

9. The lawnmower of claim 1, wherein the laser scanner is a one dimensional LIDAR scanner.

10. The lawnmower of claim 1, wherein the laser scanner is coupled to the first motor via a drive belt and coupled to the processor via serial communication.

11. A method of controlling lawnmower, comprising:

obtaining laser scanner measurements of a plurality of angles around the lawnmower, each laser scanner measurement including a distance and a received signal strength;

classifying a surface at each of the angles based on the distance and the received signal strength; and

determining a navigation path of the lawnmower based on the classification of the surface at each of the angles.

12. The method of claim 11, further comprising controlling a drive motor of the power equipment to move the lawnmower along the navigation path.

13. The method of claim 11, further comprising:

receiving a manual override signal from a remote control; and

controlling the lawnmower according to the manual override signal instead of the navigation path.

14. The method of claim 11, wherein a surface at each of the angles comprises classifying at least one surface having a signal strength above a threshold as grass.

15. The method of claim 11, wherein the laser scanner is oriented at a downward angle, and wherein classifying the surface at each of the angles comprises comparing the distance to an object detection threshold and a grass detection threshold.

16. The method of claim 15, wherein the classifying comprises classifying the surface at one or more of the angles as tall grass to be mowed when the distance is between the object detection threshold and the grass detection threshold.

17. The method of claim 16, wherein determining the navigation path comprises determining to turn the lawnmower toward the angle where the surface is classified as tall grass in response to classifying a surface in a forward direction as either an object or a lower surface.

18. The method of claim 11, further comprising:

detecting an object based on a signal strength less than a threshold strength and a detected distance less than an object detection threshold distance; and

determine the navigation path to avoid the object.

19. A non-transitory computer-readable medium storing executable code for controlling a lawnmower, comprising code to:

obtain laser scanner measurements of a plurality of angles around the lawnmower from a laser scanner rotatably mounted to the lawnmower above a cutting blade at a downward angle, each laser scanner measurement including a distance and a received signal strength;

classifying a surface at each of the angles based on the distance and the received signal strength; and

determining a navigation path of the lawnmower based on the classification of the surface at each of the angles.

20. The non-transitory computer-readable medium of claim 19, further comprising code to control a drive motor of the lawnmower to move the lawnmower along the navigation path.