Obstacle detection for a robotic working tool

• US 10,185,325 B2
• Filed: 12/19/2013
• Issued: 01/22/2019
• Est. Priority Date: 12/19/2013
• Status: Active Grant

• Current Assignee: Husqvarna AB (HUSQVARNA)
• Original Assignee: Husqvarna AB (HUSQVARNA)
• Inventors: Reigo, Peter, Sjoholm, Ludvig
• Primary Examiner(s): Zanelli, Michael J
• Application Number:
  US15/105,013
• Publication Number:
  US 20170031360A1
• Time in Patent Office: 1,860 Days
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• CPC Class Codes: A01D 75/185 Avoiding collisions with obstacles
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B60L 2200/40 Working vehicles
• CPC Class Codes: B60L 2220/46 Wheel motors, i.e. motor connected to only one wheel
• CPC Class Codes: B60L 2240/423 Torque
• 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: B60L 50/52 characterised by DC-motors
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/30 Constructional details of charging stations
• CPC Class Codes: B60L 8/003 Converting light into electric energy, e.g. by using photo-voltaic systems
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G05D 1/028 using a RF signal
• 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 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• 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 robotic work tool (100) and a beacon marker (280), said robotic work tool (100) comprising a beacon sensor (175) configured to sense a signal being transmitted by the beacon marker (280), said beacon marker (280) marking an area (270) around an obstacle (260) in a work area (205) in which said robotic work tool (100) is arranged to operate, wherein said robotic work tool is configured to determine a proximity to a beacon marker (280) and to adapt its operation accordingly.

Claims

1. A robotic lawnmower system comprising a robotic lawnmower and a beacon marker, said robotic lawnmower comprising a beacon sensor configured to sense a signal being transmitted by the beacon marker, said beacon marker marking an area around an obstacle in a work area in which said robotic lawnmower is arranged to operate, wherein said robotic lawnmower is configured to:

determine a proximity to the beacon marker and to adapt operation of the robotic work tool based on the proximity to the beacon marker.

2. The robotic lawnmower system according to claim 1, wherein the robotic lawnmower is further configured to determine the proximity to the beacon marker as a state of being close or not close by comparing a signal strength of the beacon signal to a threshold value, and if the signal strength is above the threshold value, the beacon marker is close, and, if not, the beacon marker is not close.

3. The robotic lawnmower system according to claim 1, wherein the robotic lawnmower is configured to determine the proximity to the beacon marker by comparing the signal strength of the beacon signal to a model of signal declination.

4. The robotic lawnmower system according to claim 1, wherein the robotic lawnmower is configured to determine the proximity to the beacon marker by sending a signal to the beacon marker and measuring a two-way response.

5. The robotic lawnmower system according to claim 4, wherein the robotic lawnmower is configured to determine the proximity to the beacon marker as a state of being close or not close by comparing the two-way response to a threshold value, and if the two-way response time is above the threshold value, the beacon marker is close, and, if not, the beacon marker is not close.

6. The robotic lawnmower system according to claim 4, wherein the robotic lawnmower is configured to determine a distance to the beacon marker based on the two-way response time.

7. The robotic lawnmower system according to claim 1, wherein the robotic lawnmower is configured to adapt its operation when determining a proximity to an obstacle by slowing down or making a turn less than 180 degrees.

8. The robotic lawnmower system according to claim 1, wherein the beacon marker and the beacon sensor are synchronized.

9. The robotic lawnmower system according to claim 1, wherein the beacon marker is a radio frequency beacon.

10. The robotic lawnmower system according to claim 9, wherein said beacon marker comprises fastening means for securing said beacon marker to an obstacle or a pole.

11. The robotic lawnmower system according to claim 1, wherein the beacon marker is an ultrasonic beacon.

12. The robotic lawnmower system according to claim 1, further comprising a position determining device comprising a Global Navigation Satellite System device.

13. A method for use in a robotic lawnmower system comprising a robotic lawnmower and a beacon marker, said robotic lawnmower comprising a beacon sensor configured to sense a signal being transmitted by the beacon marker, said beacon marker marking an area around an obstacle in a work area in which said robotic lawnmower is arranged to operate, said method comprising determining a proximity to a beacon marker and adapting an operation of the robotic lawnmower based on the proximity to the beacon marker.