IMPROVED NAVIGATION FOR A ROBOTIC WORKING TOOL

• US 20160278285A1
• Filed: 11/12/2013
• Published: 09/29/2016
• Est. Priority Date: 11/12/2013
• Status: Active Grant

• Current Assignee: Husqvarna AB (HUSQVARNA)
• Original Assignee: Husqvarna AB (HUSQVARNA)
• Inventors: Reigo, Peter
• Granted Patent: US 10,136,576 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: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 2200/40 Working vehicles
• CPC Class Codes: B60L 2240/16 longitudinal
• CPC Class Codes: B60L 2240/22 Yaw angle
• CPC Class Codes: B60L 2240/62 Vehicle position
• CPC Class Codes: B60L 2260/32 Auto pilot mode
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• 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 1/0278 using satellite positioning signals, e.g. GPS
• 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 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

A robotic work tool system (200) comprising a charging station (210) and a robotic work tool (100), said robotic work tool (100) comprising a position determining device (190) for determining a current position and at least one deduced reckoning navigation sensor (195), the robotic work tool (100) being configured to determine that a reliable current position is possible to determine and in response thereto calibrate at least one of the at least one deduced reckoning navigation sensor (195).

Claims

1. A robotic work tool system comprising a robotic work tool, said robotic work tool comprising a position determining device for determining a current position and at least one deduced reckoning navigation sensor, the robotic work tool being configured to

determine that a reliable current position is possible to determine and in response thereto calibrate at least one of the at least one deduced reckoning navigation sensor.

2. The robotic work tool system according to claim 1, wherein the robotic work tool is further configured to

determine an expected navigation parameter;

compare the expected navigation parameter to a current navigation parameter to determine a navigation error (Δ

);

determine if the navigation error (Δ

) is negligible; and

if the navigation error (Δ

) is not negligible, calibrate the at least one of the at least one deduced reckoning navigation sensor.

3. The robotic work tool system according to claim 2, wherein the navigation parameter is one or a combination taken from the group of navigation parameters comprising position, speed, direction, tilt angle, and acceleration.

4. The robotic work tool system according to claim 2, wherein the robotic work tool is configured to correct is current position and/or direction based on the navigation error (Δ

).

5. The robotic work tool system claim 3, wherein the robotic work tool is configured to correct its position by returning to the expected position.

6. The robotic work tool system claim 3, wherein the robotic work tool is configured to correct its position by steering towards an expected movement line.

7. The robotic work tool system according to claim 1, wherein the robotic work tool is configured to determine that a reliable current position is not possible to determine and, in response thereto continue operation using deduced reckoning navigation.

8. The robotic work tool system according to claim 1, wherein the position determining device is a Global Navigation Satellite System device.

9. The robotic work tool system according to claim 1, wherein the robotic work tool is a robotic lawnmower.

10. The robotic work tool system according to claim 1, wherein the robotic work tool is a farming equipment, a vacuum cleaner, a floor cleaner, a street sweeper, a snow removal tool, a golf ball retriever robot, a cleaner robot, a leaves blower robot, a leaves collector robot, snow thrower robot or a mine clearance robot.

11. A method for use in a robotic work tool system, comprising a robotic work tool, said robotic work tool comprising a position determining device for determining a current position and at least one deduced reckoning navigation sensor, the method comprising determining that a reliable current position is possible to determine and in response thereto calibrating at least one of the at least one deduced reckoning navigation sensor.