Navigation for a robotic working tool

• US 10,444,756 B2
• Filed: 12/11/2014
• Issued: 10/15/2019
• Est. Priority Date: 12/11/2014
• Status: Active Grant

• Current Assignee: Husqvarna AB (HUSQVARNA)
• Original Assignee: Husqvarna AB (HUSQVARNA)
• Inventors: Kamfors, Mattias, Ohrlund, Magnus
• Primary Examiner(s): Badii, Behrang
• Assistant Examiner(s): Greene, Daniel L
• Application Number:
  US15/534,201
• Publication Number:
  US 20170344012A1
• Time in Patent Office: 1,769 Days
• CPC Class Codes: A01D 2101/00 Lawn-mowers
• 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 34/78 electric
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 2200/40 Working vehicles
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2260/32 Auto pilot mode
• CPC Class Codes: B60L 3/0061 relating to electrical machines
• CPC Class Codes: B60L 50/52 characterised by DC-motors
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60L 53/16 Connectors, e.g. plugs or sockets, specially adapted for charging electric vehicles
• CPC Class Codes: B60L 8/003 Converting light into electric energy, e.g. by using photo-voltaic systems
• CPC Class Codes: G05D 1/0219 ensuring the processing of the whole working surface
• 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 1/0265 using buried wires
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30
• CPC Class Codes: G05D 1/0278 : using satellite positioning signals, e.g. GPS
• 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 90/14 : Plug-in electric vehicles

Abstract

A robotic work tool system (200) comprising a charging station (210) and a robotic work tool (100) configured to work within a work area (205) being divided into at least one section (405), the robotic work tool comprising a controller (110) for controlling the operation of the robotic work tool (100) to cause the robotic work tool to move along a trajectory, the robotic work tool (100) being configured to determine that a section boundary is encountered, and if so change the trajectory of the robotic work tool (100) to cause the robotic work tool to remain in the section.

Claims

1. A robotic work tool system comprising a charging station and a robotic work tool, the robotic work tool comprising a controller, the controller being configured to divide a work area into a plurality of sections and control the operation of the robotic work tool to cause the robotic work tool to move along a trajectory within a section of the plurality of sections, the robotic work tool being configured to determine that a boundary of the section is encountered, and if so change the trajectory of the robotic work tool to cause the robotic work tool to remain within the section.

2. The robotic work tool system according to claim 1, wherein the robotic work tool is further configured to determine whether the boundary of the section borders on a next section of the plurality of sections, and if not, change the trajectory of the robotic work tool when it is determined that the switch section signal has been received.

3. The robotic work tool system according to claim 1, wherein the robotic work tool is a robotic lawnmower, and wherein the robotic work tool system further comprises a boundary wire arranged to enclose the work area.

4. The robotic work tool system of claim 1, wherein the robotic work tool is further configured to order the plurality of sections in a working order and visit each of the sections according to the working order.

5. The robotic work tool system according to claim 1, wherein the robotic work tool is further configured to determine whether a switch section signal has been received, and if not, change the trajectory of the robotic work tool.

6. The robotic work tool system according to claim 5, wherein the robotic work tool is further configured to determine that a boundary wire is encountered, and if so, determine if the switch section signal has been received and if so follow the boundary wire out of the section.

7. The robotic work tool system according to claim 6, wherein the robotic work tool is further configured to determine that the switch section signal has been received when an associated section time has been exceeded.

8. The robotic work tool system according to claim 6, wherein the robotic work tool is further configured to receive the switch section signal through the boundary wire.

9. The robotic work tool system according to claim 6, wherein the robotic work tool is further configured to receive the switch section signal through user input.

10. The robotic work tool system according to claim 1, wherein the robotic work tool further comprises a position determining device and wherein the boundary of the section is virtual and the robotic work tool is configured to determine that it has encountered the boundary through use of the position determining device.

11. The robotic work tool system according to claim 10, wherein the section is defined by coordinates.

12. The robotic work tool system according to claim 10, wherein the section is defined relative to a position of the robotic work tool.

13. The robotic work tool system according to claim 10, wherein the boundary is also physical and determined through use of beacons or other navigation means such as a section boundary wire in combination with the position determining device.

14. The robotic work tool system according to claim 10, wherein the position determining device is a Global Navigation Satellite System device.

15. The robotic work tool system of claim 1, wherein the robotic work tool is further configured to associate a section time with the section and spend at least the section time within the section, and wherein the robotic work tool is further configured to determine if the section time has been exceeded, and if so, leave the section.

16. The robotic work tool system of claim 15, wherein the section time is based on a size of the section, a configuration or complexity of the section, or a number of obstacles in the section.

17. A robotic work tool comprising a controller configured to divide a section of a work area into a plurality of subsections and control the operation of the robotic work tool to cause the robotic work tool to move along a trajectory within a subsection of the plurality of subsections, the robotic work tool being configured to determine that a boundary of the subsection is encountered, and if so change the trajectory of the robotic work tool to remain within the subsection.

18. A method for controlling operation of a robotic work tool comprising a controller, the method comprising:

dividing, via the controller, a work area into a plurality of sections;

causing, via the controller, the robotic work tool to work within a section of the plurality of sections;

determining that a boundary of the section is encountered, and if so changing the trajectory of the robotic work tool to remain within the section.

19. The method according to claim 18, wherein the method further comprises determining if a switch section signal has been received, and if not, changing the trajectory of the robotic work tool.