TETHERED ROBOT POSITIONING

• US 20110202224A1
• Filed: 02/16/2010
• Published: 08/18/2011
• Est. Priority Date: 02/16/2010
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Thompson, Jeffrey S., Anderson, Noel Wayne
• Granted Patent: US 8,234,010 B2
• Time in Patent Office: Days
• US Class Current: 701/26
• CPC Class Codes: G05D 1/0227 using mechanical sensing means, e.g. for sensing treated area
• CPC Class Codes: G05D 1/0234 using optical markers or beacons optical beacons per se G01S1/70
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• 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: G05D 1/0295 by at least one leading vehicle of the fleet

Abstract

A system and method for positioning a mobile machine, such as a robot, using a tether line connected between two mobile machines. A first mobile machine, such as a boundary vehicle, is controlled to move along a path, such as a boundary defining an area. The first machine employs a localization device to determine and maintain its position on the path. A tether line is connected between the boundary vehicle and a second mobile machine, such as a roving vehicle. The first machine determines the position of the second machine relative to the first machine from a length of extension and angle of the tether line. The first machine controls movement of the second machine to perform a task or mission, such as a task performed in the area defined by the boundary.

Claims

1. A mobile machine, comprising:

a localization detection device;

an extendable tether line; and

a controller coupled to the localization detection device and configured to control automatically movement of the machine along a defined path and to control movement of a second machine attached to a distal end of the tether line, wherein the movement of the second machine is dependent upon a position of the mobile machine but independent of the defined path of the mobile machine.

2. The mobile machine of claim 1, wherein the defined path is a boundary defining an area and wherein the controller is configured to control the movement of the second machine to perform a task in the area.

3. The mobile machine of claim 1 further comprising:

a body;

movable ground engaging structures attached to the body; and

a motor coupled to the movable ground engaging structures to drive the movable ground engaging structures to move the machine.

4. The mobile machine of claim 3, wherein the movable ground engaging structures are selected from the group of movable ground engaging structures consisting of wheels, tracks, and legs.

5. The mobile machine of claim 1, wherein the defined path is defined by a wire carrying a signal and wherein the localization detection device includes a device for detecting the signal in the wire.

6. The mobile machine of claim 1 further comprising:

a line extension monitoring device configured to monitor a length of extension of the tether line; and

a line angle monitoring device configured to monitor an angle of the tether line; and

wherein the controller is coupled to the line extension monitoring device and to the line angle monitoring device and is configured to determine a relative position of the second machine from the monitored length of extension and the monitored angle of the tether line.

7. The mobile machine of claim 6, wherein the tether line is wound around a spool and wherein the line extension monitoring device is configured to monitor the length of extension of the tether line by monitoring a rotation of the spool.

8. The mobile machine of claim 6, wherein the line angle monitoring device is configured to monitor the angle of the tether line in both a horizontal plane and a vertical plane.

9. The mobile machine of claim 1 further comprising a second machine attached at the distal end of the tether line, wherein the second machine comprises:

a second machine body;

second movable ground engaging structures attached to the second machine body;

a second machine motor coupled to the movable ground engaging structures to move the machine; and

a second machine controller configured to control movement of the second machine.

10. The mobile machine of claim 9, wherein:

the controller is further configured to generate control signals to control the movement of the second machine;

the mobile machine further comprises a transmitter coupled to the controller to transmit the control signals to the second machine;

the second machine further comprises a receiver coupled to the second machine controller to receive the control signals from the mobile machine; and

the second machine controller is configured to control movement of the second machine in response to the control signals from the mobile machine.

11. The mobile machine of claim 10, wherein the control signals are transmitted wirelessly from the mobile machine to the second machine.

12. The mobile machine of claim 10, wherein the control signals are transmitted via the tether line from the mobile machine to the second machine.

13. The mobile machine of claim 9 further comprising a task payload on the second mobile machine.

14. The mobile machine of claim 13, wherein the task payload is selected from the group of task payloads consisting of a mower, a cargo hold, a vacuum, a sweeper, a tiller, a plow, a snow remover, and a spreader.

15. The mobile machine of claim 9, comprising additionally a second localization detection device on the second machine configured to detect the defined path.

16. A method of controlling a mobile machine, comprising:

detecting by a first mobile machine a position of the first mobile machine along a path;

automatically moving the first mobile machine along the path;

determining by the first mobile machine a position of a second mobile machine relative to the first mobile machine; and

controlling automatically movement of the second mobile machine by the first mobile machine, wherein the controlled movement of the second mobile machine is dependent upon the position of the first mobile machine along the path but independent of the movement of the first mobile machine along the path.

17. The method of claim 16, wherein the detecting step includes detecting a signal in a wire defining the path.

18. The method of claim 16, wherein the determining step includes connecting a tether line under tension between the first mobile machine and the second mobile machine and determining the position of the second mobile machine from an extension length of the tether line and an angle of the tether line.

19. The method of claim 16, wherein the path is a boundary defining an area, and wherein the controlling step includes controlling movement of the second machine in the area to perform a task in the area.

20. The method of claim 16, wherein the path is a boundary defining an area, and wherein the controlling step includes controlling movement of the second machine along the path to create a map of the area.

21. The method of claim 20 further comprising detecting by the second mobile machine a position of the second mobile machine relative to the path.

22. A system for positioning a mobile machine, comprising:

a first mobile machine;

a localization detection device on the first mobile machine configured to detect a position of the first mobile machine along a path;

a tether line extendable from the first mobile machine and under tension;

a line extension monitoring device configured to monitor a length of extension of the tether line;

a line angle monitoring device configured to monitor an angle of the tether line;

a second mobile machine attached at a distal end of the tether line;

a first controller connected to the localization detection device, to the line extension monitoring device, and to the line angle monitoring device and configured to control automatically movement of the first mobile machine along a defined path, to determine a relative position of the second mobile machine from the monitored length of extension and monitored angle of the tether line, and to generate movement control signals to control movement of the second mobile machine;

a transmitter connected to the first controller and configured to transmit the movement control signals to the second mobile machine;

a receiver configured to receive the movement control signals at the second mobile machine; and

a second controller connected to the receiver and configured to control a position of the second mobile machine in response to the movement control signals received at the second mobile machine.

23. The system of claim 22, wherein the defined path is defined by a wire carrying a signal and wherein the localization detection device includes a device for detecting the signal in the wire.

24. The system of claim 22, wherein the tether line is wound around a spool and wherein the line extension monitoring device is configured to monitor a length of extension of the tether line by monitoring a rotation of the spool.

25. The system of claim 22, wherein the line angle monitoring device is configured to monitor an angle of the tether line in both a horizontal plane and a vertical plane.

26. The system of claim 22, wherein the movement control signals are transmitted wirelessly from the first mobile machine to the second mobile machine.

27. The system of claim 22, wherein the movement control signals are transmitted via the tether line from the first mobile machine to the second mobile machine.

28. The system of claim 22, wherein the defined path is a boundary defining an area and wherein the first controller is configured to generate movement control signals to control the movement of the second mobile machine to perform a task in the area.

29. The system of claim 28, wherein the second mobile machine further comprises a task payload configured to perform the task.

30. The system of claim 29, wherein the task payload is selected from the group of task payloads consisting of a mower, a cargo hold, a vacuum, a sweeper, a tiller, a plow, a snow remover, and a spreader.

31. The system of claim 22 further comprising a second localization detection device on the second mobile machine configured to detect the defined path.

32. A mobile machine, comprising:

a receiver configured to receive control signals from a master mobile machine connected to the mobile machine by a tether line, wherein the control signals are adapted to control movement of the mobile machine dependent upon a location of the master mobile machine but independent of a path of movement of the master mobile machine; and

a controller coupled to the receiver and configured to control movement of the mobile machine in response to the control signals.

33. The mobile machine of claim 32, wherein the receiver is configured to receive the control signals transmitted wirelessly from the master mobile machine to the mobile machine.

34. The mobile machine of claim 32, wherein the receiver is configured to receive the control signals transmitted via the tether line from the master mobile machine to the mobile machine.

35. A method of controlling a mobile machine, comprising:

receiving first control signals from a master mobile machine connected by a tether line to the mobile machine, wherein the first control signals are adapted to control movement of the mobile machine through a first portion of a defined area relative to a first location of the master mobile machine; and

receiving second control signals from the master mobile machine, wherein the second control signals are adapted to control movement of the mobile machine through a second portion of the defined area relative to a second location of the master mobile machine, wherein the controlled movement of the mobile machine is dependent upon the location of the master mobile machine but independent of a path taken by the master mobile machine between the first location and the second location.

36. The method of claim 35, wherein receiving the first and second control signals from the master mobile machine includes receiving the first and second control signals wirelessly from the master mobile machine.

37. The method of claim 35, wherein receiving the first and second control signals from the master mobile machine includes receiving the first and second control signals via the tether line from the master mobile machine.

38. The method of claim 35, wherein the defined area is defined by a path of movement of the master mobile machine including the first location and the second location.