Navigation method and system for autonomous machines with markers defining the working area

• US 6,255,793 B1
• Filed: 11/07/1995
• Issued: 07/03/2001
• Est. Priority Date: 05/30/1995
• Status: Expired due to Term

• Current Assignee: F Robotics Acquisitions Ltd. (Stanley Black & Decker, Inc.)
• Original Assignee: Friendly Robotics Ltd (Whirlpool Corporation)
• Inventors: Abramson, Shai, Peless, Ehud, Dror, Gideon
• Primary Examiner(s): SALATA, ANTHONY J
• Application Number:
  US08/554,691
• Time in Patent Office: 2,065 Days
• Field of Search: 180/167-169, 318/568.12, 318/568.16, 318/568.17, 318/580, 318/587, 364/424.02, 364/449, 364/443, 364/459, 364/461, 153/19, 56/102.K, 56/102.A, 56/102.F, 56/102.J
• US Class Current: 318/580
• CPC Class Codes: A01D 2101/00 Lawn-mowers
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• CPC Class Codes: G01C 22/00 Measuring distance traversed on the ground by vehicles, persons, animals or other moving solid bodies, e.g. using odometers, using pedometers
• CPC Class Codes: G05D 1/0219 ensuring the processing of the whole working surface
• 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 1/0261 using magnetic plots
• CPC Class Codes: G05D 1/0263 using magnetic strips
• CPC Class Codes: G05D 1/0265 using buried wires
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30

Abstract

A method for automatically operating a robot, attached to a lawnmower or other unmanned machine, within an enclosed area is disclosed. The method includes the steps of: 1) providing the following elements: a proximity sensor positioned on the robot, a boundary along the perimeter of the working area and along the perimeter of each area enclosed in the working area in which the robot should not operate, the boundaries being detectable by the proximity sensor, a processing unit connected to the proximity sensor and receiving an input therefrom, a navigation unit on the robot to determine the coordinates of the robot relative to an arbitrary origin, a direction finder, and a memory to store values generated by the processing unit; and 2) causing the robot to move along each of the boundaries provided around or within the working area, to detect the boundaries and to memorize their shape, and to store in the memory values representative of the coordinates of the boundaries, thereby to generate a basic map of the working area. When the robot is to operate within the area, the method includes the steps of: (a) causing the robot to start from a starting point having known coordinates within the basic map of the working area; (b) continuously determining the coordinates of the robot by analyzing data obtained from the navigation unit and by detecting the vicinity of a boundary; and (c) correcting the actual position of the robot on the basic map by comparing the calculated and the actual coordinates of each detected boundary.

Claims

1. A method for automatically operating a robot within a working area enclosed by a boundary comprising the steps of:

providing a boundary along edges of an area so as to provide a boundary outlining the working area, said boundary being detectable by a sensor;

providing boundaries along edges of each area enclosed in the working area, in which it is desired that the robot should not operate, said boundaries also being detectable by a sensor;

providing a sensor positioned on the robot, said sensor for detecting said boundaries;

providing processing means connected to said sensor and receiving an input therefrom;

providing location means on said robot to determine the coordinates of the robot relative to an arbitrary origin, at any specific time;

providing direction finding means on said robot;

providing memory means to store values generated by said processing means and, optionally, by said location means;

moving said robot into said area;

(a) causing the robot to move along each of the boundaries provided around or within said working area and to make a complete traversal of said boundary outlining said working area, to detect said boundaries and to memorize their shape, and to store in the memory means values representative of the coordinates of said boundaries, relative to an arbitrary origin, thereby to initially generate a basic map of the working area;

(b) causing the robot to start from an arbitrary starting point having known coordinates within the basic map of the working area;

(c) causing said robot to move autonomously along a path, said path comprising at least a plurality of substantially straight lines between portions of said boundaries, and to detect a boundary when in the vicinity of the boundary; and

(d) during said movement;

continuously determining the coordinates of the robot by analyzing data obtained from the location means and by detecting the vicinity of a boundary; and

correcting the actual position of the robot on the basic map by comparing the calculated and the actual coordinates of each detected boundary.

2. A method according to claim 1, wherein the location means comprise movement measuring means.

3. A method according to claim 2, wherein the movement measuring means comprise an odometer.

4. A method according to claim 1, wherein the robot is coupled to a selected one of the group of:

a vacuum cleaner, a floor sweeper and a floor polisher.

5. A method according to claim 1, wherein the robot is coupled to a lawn mower.

6. A method according to claim 5 and including the steps of:

providing the lawnmower with at least a plurality of lawn height sensors;

cutting a first swath of lawn in a first direction;

performing a maneuver, under control of said robot and in response to output of said lawn height sensors, in a second direction generally opposite of said first direction to bring said lawnmower to a location parallel to but overlapping said first swath by a predetermined percentage as indicated by the different output of said lawn height sensors;

cutting a second swath of lawn parallel to said first swath while continually monitoring the lawn height output of said lawn height sensors thereby to ensure that the percentage of overlap is generally maintained;

repeating said steps of performing a maneuver and cutting a second swath for further swaths of lawn, wherein the previously cut lawn is denoted by said first swath of lawn and the swath to be cut is denoted by said second swath of lawn.

7. The method of claim 1, wherein said step of causing said robot to move autonomously along a path, includes moving along said path substantially free of repetition.

8. A method according to claim 1 wherein the sensor is a proximity sensor.

9. A method according to claim 8, wherein the boundary comprises a metallic wire through which electric current flows, and the proximity sensor comprises a magnetic field detector.

10. A method according to claim 8, wherein the boundary comprises a guide wire through which an acoustic signal passes, and the proximity sensor comprises an acoustic detector.

11. A method according to claim 8, wherein the boundary comprises passive metallic means which is excitable by a magnetic field, and the proximity sensor comprises an electric field detector.

12. A method according to claim 8, wherein the boundary comprises passive magnetic means, and the proximity sensor comprises a magnetic field detector.

13. A method according to claim 10, wherein the acoustic signal is in the ultra-sound range.

14. A method according to claim 12, wherein said passive magnetic means comprises a plurality of pins having magnets therein.

15. A method according to claim 12, wherein said passive magnetic means comprises a multiplicity of magnets each shaped into the form of pins.

16. A method according to claim 8, wherein the proximity sensor comprises a high contrast pattern code reader and the boundary comprises high contrast pattern means.

17. A method according to claim 16, wherein the boundary comprises a two color guide wire having patterns of a first color at fixed distances thereon and a second color for the non-patterned portions of the guide wire.

18. A method according to claim 16, wherein the boundary comprises a multiplicity of pins each having a high contrast pattern thereon.

19. A method according to claim 8, wherein the proximity sensor comprises a radiometer and the boundary comprises radioactive means.

20. A method according to claim 19, wherein the boundary comprises a guide wire having a radioactive unit placed at fixed distances thereon.

21. A method according to claim 19, wherein the boundary comprises a multiplicity of pins each having a radioactive unit thereon.

22. A method according to claim 8, wherein the proximity sensor comprises a resonance tag meter and the boundary comprises a multiplicity of pins having at least one coil-capacitive circuit therein.

23. A method according to claim 8, wherein the proximity sensor comprises a transceiver and the boundary comprises a multiplicity of pins having at least one transceiver therein.

24. A system for automatically operating a robot within a working area enclosed by a boundary, comprising:

boundary means suitable for positioning along the edges of the working area, and of each area enclosed in the working area, in which it is desired the robot not to operate, said boundary means being detectable by a sensor; and

a robot comprising;

a sensor for detecting said boundary means;

processing means on said robot in operative communication with said sensor and receiving an input therefrom, said processing means including means for initially generating a map of said working area in accordance with a complete traversal of said boundary means;

location means on said robot, to determine the coordinates of the robot relative to an arbitrary origin, at any specific time;

memory means to store values generated by said processing means;

direction finding means position on said robot, to determine the direction of travel thereof; and

motion means, to cause the robot to move in a substantially continuous operative mode, in a plurality of substantially straight lines between portions of said boundary means within said working area.

25. A system according to claim 24, wherein the boundaries are provided with a plurality of individually recognizable markers.

26. A system according to claim 25, wherein the markers are substantially located at even distances from one another.

27. A system according to claim 25, wherein the marker comprises an RF tag or a magnetic tag.

28. A system according to claim 24, wherein the movement measuring means comprise an odometer.

29. A system according to claim 24, wherein the robot is coupled to a lawn mower.

30. A system according to claim 24, wherein the robot is coupled to a device selected from the group of:

a vacuum cleaner, a floor sweeper and a floor polisher.

31. A system according to claim 29 and additionally including a plurality of lawn height sensors for measuring the height of the lawn and means for controlling said lawn mower to cut the lawn along an already cut swath of grass.

32. The system of claim 24, additionally comprising, said location means, said motion means and said memory means in operative communication for moving said robot in said operative mode within said working area along a path substantially free of repetition.

33. A system according to claim 24 wherein the sensor is a proximity sensor.

34. A system according to claim 33, wherein the boundary means which is detectable by a proximity sensor comprises a metallic wire through which electric current flows, and the proximity sensor comprises a magnetic field detector.

35. A system according to claim 33, wherein the boundary which is detectable by a proximity sensor comprises a guide wire through which an acoustic signal passes, and the proximity sensor comprises an acoustic detector.

36. A system according to claim 33, wherein the boundary which is detectable by a proximity sensor comprises a passive metallic means which is excitable by a magnetic field, and the proximity sensor comprises an electric field detector.

37. A system according to claim 33, wherein the boundary which is detectable by a proximity sensor comprises passive magnetic means, and the proximity sensor comprises a magnetic field detector.

38. A system according to claim 33, wherein the boundary comprises passive magnetic means, and the proximity sensor comprises a magnetic field detector.

39. A system according to claim 38, wherein said passive magnetic means comprises a plurality of pins having magnets therein.

40. A system according to claim 38, wherein said passive magnetic means comprises a multiplicity of magnets each shaped into the form of pins.

41. A system according to claim 33, wherein the proximity sensor comprises a high contrast pattern code reader and the boundary comprises high contrast pattern means.

42. A system according to claim 41, wherein the boundary comprises a two color guide wire having patterns of a first color at fixed distances thereon and a second color for the non-patterned portions of the guide wire.

43. A system according to claim 41, wherein the boundary comprises a multiplicity of pins each having a high contrast pattern thereon.

44. A system according to claim 33, wherein the proximity sensor comprises a radiometer and the boundary comprises radioactive means.

45. A system according to claim 44, wherein the boundary comprises a guide wire having a radioactive unit placed at fixed distances thereon.

46. A system according to claim 44, wherein the boundary comprises a multiplicity of pins each having a radioactive unit thereon.

47. A system according to claim 33, wherein the proximity sensor comprises a resonance tag meter and the boundary comprises a multiplicity of pins having at least one coil-capacitive circuit therein.

48. A system according to claim 33, wherein the proximity sensor comprises a transceiver and the boundary comprises a multiplicity of pins having at least one transceiver therein.