ROBOTIC MOWER BOUNDARY COVERAGE SYSTEM

• US 20120029756A1
• Filed: 07/28/2010
• Published: 02/02/2012
• Est. Priority Date: 07/28/2010
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Johnson, David A., Dickson, Monte A.
• Granted Patent: US 8,352,113 B2
• Time in Patent Office: Days
• US Class Current: 701/26
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• 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

Abstract

A robotic mower boundary coverage system includes a vehicle control unit on the robotic mower commanding a traction drive system to drive the robotic mower at a specified yaw angle with respect to a boundary wire, and a boundary sensor on the robotic mower signaling the distance between the boundary wire and the vehicle control unit. The vehicle control unit alternates commands to direct the traction drive system toward and away from the boundary wire based on the distance of the robotic mower to the boundary wire.

Claims

1. A robotic mower boundary coverage system, comprising:

a vehicle control unit on the robotic mower commanding a traction drive system to drive the robotic mower at a specified yaw angle with respect to a boundary wire;

a boundary sensor on the robotic mower signaling the distance between the boundary wire and the vehicle control unit;

the vehicle control unit alternating commands to direct the traction drive system toward and away from the boundary wire based on the distance of the robotic mower to the boundary wire.

2. The robotic mower boundary coverage system of claim 1 wherein the yaw angle is 45 degrees.

3. The robotic mower boundary coverage system of claim 1 wherein the vehicle control unit determines the orientation angle of the robotic mower with respect to the boundary wire.

4. The robotic mower boundary coverage system of claim 3 wherein the vehicle control unit calculates the orientation angle using a trigonometric relationship between a plurality of boundary sensors on the robotic mower.

5. A robotic mower boundary coverage system, comprising:

a vehicle control unit on the robotic mower commanding a traction drive system to drive the robotic mower at a specified distance with respect to a boundary wire;

a boundary sensor on the robotic mower signaling the actual distance between the robotic mower and the boundary wire;

the vehicle control unit commanding the traction drive system to turn the robotic mower at a specified angle based on the difference between the specified distance and the actual distance of the robotic mower to the boundary wire.

6. The robotic mower boundary coverage system of claim 5, wherein the vehicle control unit commands the traction drive system to turn the robotic mower at a reduced angle if the difference between the specified distance and the actual distance is reduced.

7. The robotic mower boundary coverage system of claim 5 wherein the vehicle control unit commands the traction drive system to drive the robotic mower straight ahead if the difference between the specified distance and the actual distance is under a threshold distance.

8. The robotic mower boundary coverage system of claim 5 wherein the traction drive system includes a left wheel motor and right wheel motor.

9. A robotic mower boundary coverage system, comprising:

a vehicle control unit commanding a traction drive system to mow in a pattern including alternating travel of the robotic mower toward the boundary wire and away from the boundary wire.

10. The robotic mower boundary coverage system of claim 9 wherein the vehicle control unit commands the robotic mower to travel away from the boundary wire when a boundary sensor detects the robotic mower is within a minimum distance to the boundary wire.

11. The robotic mower boundary coverage system of claim 9 wherein the vehicle control unit commands the robotic mower to travel toward the boundary wire when a boundary sensor detects the robotic mower is farther than a maximum distance to the boundary wire.

12. The robotic mower boundary coverage system of claim 9 wherein the vehicle control unit selects boundary coverage if boundary coverage was not executed in a specified preceding time period.