A Robotic Work Tool System and Method Comprising a Charging Station

• US 20150366137A1
• Filed: 02/20/2013
• Published: 12/24/2015
• Est. Priority Date: 02/20/2013
• Status: Active Grant

• Current Assignee: Husqvarna AB (HUSQVARNA)
• Original Assignee: Husqvarna AB (HUSQVARNA)
• Inventors: Markusson, Olle, Jgenstedt, Patrik, Hallin, Peter
• Granted Patent: US 9,872,437 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• CPC Class Codes: A01D 69/02 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 1/0225 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 1/03 using near-field transmission systems, e.g. inductive-loop type G05D1/021 and subgroups take precedence
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• 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), a boundary wire (250), a signal generator (240) for generating and transmitting a signal through said boundary wire (250) for demarcating a work area (205) and for generating a magnetic field (265) for guiding a robotic work tool (100) to said charging station (210), said robotic work tool (100) being configured to detect a magnetic field strength of the magnetic field (265) in the work area (205), direct itself towards an increasing magnetic field strength, determine that the robotic work tool (100) is unable to reach the charging station (210), inform the robotic work tool system (200) accordingly, whereby the robotic work tool system (200) is configured to adapt a current level of the signal generating the magnetic field (365).

Claims

1. A robotic work tool system comprising:

a charging station, a boundary wire, a signal generator for generating and transmitting a signal through said boundary wire for demarcating a work area and for generating a magnetic field for guiding a robotic work tool to said charging station, said robotic work tool being configured to;

detect a magnetic field strength of the magnetic field in the work area;

direct the robotic work tool towards an increasing magnetic field strength;

determine that the robotic work tool is unable to reach the charging station; and

adapt a detection of the magnetic field.

2. The robotic work tool system according to claim 1, wherein the robotic work tool is configured to adapt the detection of the magnetic field by:

informing the robotic work tool system accordingly, whereby the robotic work tool system is configured to adapt a current level of the signal generating the magnetic field.

3. The robotic work tool system according to claim 1, wherein the robotic work tool is configured to adapt the detection of the magnetic field by adjusting a threshold level for detecting the magnetic field.

4. The robotic work tool system according to claim 1, wherein the robotic work tool is configured for manual adaptation.

5. The robotic work tool system according to claim 1, wherein the robotic work tool is configured for automatic adaptation.

6. The robotic work tool system according to claim 1, wherein the robotic work tool is configured to determine that it is being unable to reach the charging station based on how many times it collides with an object while trying to find the charging station.

7. The robotic work tool system according to claim 1, wherein the robotic work tool is configured to determine that it is being unable to reach the charging station based on how long time it spends trying to find the charging station.

8. The robotic work tool system according to claim 1, wherein the robotic work tool system is configured to adapt the magnetic field by decreasing it.

9. The robotic work tool system according to claim 1, wherein the robotic work tool is further configured to determine that it is often or always able to reach the charging station and in response thereto inform the robotic work tool system accordingly to adapt the magnetic field to an increased range.

10. The robotic work tool system according to claim 1, wherein said robotic work tool is configured for communication during a working session and for instructing said robotic work tool system to dynamically adapt the magnetic field during said working session.

11. The robotic work tool system according to claim 1, wherein robotic work tool is a robotic lawn mower.

12. A method for use in a robotic work tool system, comprising a charging station, a boundary wire, a signal generator for generating and transmitting a signal through said boundary wire for demarcating a work area and for generating a magnetic field for guiding a robotic work tool to said charging station, said method comprising:

detecting a magnetic field strength of the magnetic field in the work area;

directing the robotic work tool towards an increasing magnetic field strength;

determining that the robotic work tool is unable to reach the charging station; and

adapt a detection of the magnetic field.

13. The method according to claim 12, further comprising adapting the detection of the magnetic field by:

informing the robotic work tool system accordingly; and

adapting a current level of the signal generating the magnetic field.

14. The method according to claim 12, further comprising adapting the detection of the magnetic field by adjusting a threshold level for detecting the magnetic field.