Electronic directing system

• US 7,574,282 B2
• Filed: 06/03/2003
• Issued: 08/11/2009
• Est. Priority Date: 06/07/2002
• Status: Active Grant

• Current Assignee: Husqvarna AB (HUSQVARNA)
• Original Assignee: Husqvarna AB (HUSQVARNA)
• Inventors: Bergvall, Bengt-Allan, Petersson, Ulf
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Marc; McDieunel
• Application Number:
  US10/516,793
• Publication Number:
  US 20050267629A1
• Time in Patent Office: 2,261 Days
• Field of Search: 700/245, 700/253, 700/254, 700/255, 700/258, 700/262, 700/302, 700/248, 318/568.12, 318/580, 318/581, 318/587, 180/167, 180/168, 180/169, 701/50, 701/213, 701/23, 701/24, 701/25, 701/28, 701/200, 701/207, 701/208, 701/212, 701/214, 701/301, 901/1, 901/9, 901/23, 901/42, 901/47, 342/357.06, 342/357.1, 342/357.13, 342/358, 348/36, 348/38, 348/39, 348/113, 219/124.34, 382/107, 382/278, 382/279, 606/130
• US Class Current: 700/245
• CPC Class Codes: A01D 2101/00 Lawn-mowers
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• 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 2260/32 Auto pilot mode
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• 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
• CPC Class Codes: Y02P 90/60 Electric or hybrid propulsion means for production processes
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

The present disclosure relates to an arrangement and an electronic navigational control system for a self-propelling device (5), preferably a lawn-mowing robot. The system comprises at lease one navigational control system (3) connected to at least one signal generator (1) and a sensing unit arranged at the self-propelling device (5). The sensing unit senses at least one, in the air medium propagating, time and space varying magnetic field, at least transmitted via the navigational control station (3) and in turn retransmits at least one signal processed by the unit to at least one driving source which contributes to the device'"'"'s movements across the surface. The system comprises structure by which the signal generator (1) sends a current through the navigational control station (3), the current generating the time and space varying magnetic field, whereby the sensing unit comprises structure by which the device (5) is maneuvered based on the properties of the sensed magnetic field.

Claims

1. Method for maneuvering a self-propelling device (5) towards a navigational control station (3) by means of an electronic navigational control system comprising at least said navigational control station (3) with at least one loop (4) connected to at least one signal generator (1) and one sensing unit (14,15,16) arranged at the self-propelling device (5), whereby the sensing unit (14,15,16) at least senses an, in the air-medium propagating, time and space varying magnetic field, transmitted by the at least one loop (4) and in turn retransmits at least one, by the sensing unit (14,15,16) processed signal to at least one drive source that contributes to the device'"'"'s (5) movements across a surface, the signal generator (1) sends a current through the at least one loop (4), the current generating the time and space varying magnetic field (43,44,52,54), whereby the sensing unit (14,15,16) maneuvers the device (5) based on the properties of the sensed magnetic field (43,44,52,54),

characterised in that said sensed magnetic field (43,44,52,54), in an area enclosed by said loop (4), at least at one point of time has different directions (50,51).

2. Method according to claim 1 characterised in that the device (5), when moving mainly outside the range of the navigational control station and sensing a change in the magnetic field (44,54), maneuvers itself in relation to the navigational control station (3) so that it by means of one or many maneuvers will approach, essentially stay at a constant distance from or distance itself from the navigational control station (3), alternatively stop and/or turn.

3. Method according to claim 2 characterised in that the device (5), when moving in a course direction and senses an unchanged magnetic field strength (44,54), changes directions 90degrees, that the device, when moving in a course direction and senses an increased magnetic field strength (44,54), continues in the same course direction and that the device, when moving in a course direction and senses a decreased magnetic field strength (44,54), changes course directions 180degrees.

4. Method according to claim 2 characterised in that the device (5) moves in a course direction that corresponds to that the sensed magnetic field (44, 54) is constant.

5. Method according to claim 2 characterised in that the device (5), when sensing that the magnetic field (44,54) changes directions (55), continues to move a certain distance in the same direction, then stops and turns until it again detects that the magnetic field (44,54) changes directions (55), whereupon it moves essentially in the same direction as a line (55), which ties together points where the sensed magnetic field (44,54) changes directions.

6. Method according to claim 1 characterised in that the sensing unit (14,15,16), when sensing the magnetic field (43,52) within the range of the navigational control station (3), adapts its processing of the sensed magnetic field (43,52).

7. Method according to claim 1 characterised in that at least one signal generator (1) sends a first current trough the navigational control station (3), whereby the magnetic field (43,44), generated by the current at a point of time mainly inside the range of the navigational control station (3), has a direction essentially opposed to the direction of the magnetic field (43,44) at the same point of time mainly outside of the mentioned range.

8. Method according to claim 1 characterised in that at least one signal generator (1) sends a second current through the navigational control station (3) and the mentioned (1) or another signal generator (1) sends a third current through the navigational control station (3), whereby the magnetic field (43,44), generated by the second current in a second area mainly within the range of the navigational control station (3), at a point of time has a direction essentially corresponding to the direction (46) of the magnetic field (43,44) generated by the third current at the same point of time in a third area mainly within the range of the navigational control station (3).

9. Method according to claim 8 characterised in that the second current corresponds to the third current.

10. Method according to claim 1 characterised in that at least one signal generator (1) sends a second current trough the navigational control station (3) and the mentioned (1) or another signal generator (1) sends a third current through the navigational control station (3), whereby the magnetic field (52,54), generated by the second current in a second area mainly within the range of the navigational control station (3), at a point of time has a direction essentially opposite to the direction (50,51) of the magnetic field (52,54) generated by the third current at the same point of time in a third area mainly within the range of the navigational control station (3).

11. Method according to claim 8 characterised in that the direction (46,50,51) of the magnetic fields (43,44,52,54) generated in the second and third areas depend on the properties of the sent currents.

12. Method according to claim 8 characterised in that the magnetic field'"'"'s (43,44,52,54) direction (46,50,51) within the second and the third areas respectively at a point of time depends on the properties and the occurrence of current pulses (7,9,11).

13. Method according to claim 8 characterised in that when a first current pulse N7 (9) occurs, the magnetic field (54) in the second area, at a point of time, shows a direction (50) essentially opposed to the direction (51) of the magnetic field at the same point of time in the third area and when another current pulse F9 (11) occurs, the magnetic field (54) in the second area, at a point of time, shows a direction (46) essentially corresponding to the direction (46) of the magnetic field in the third area.

14. Method according to claim 10 characterised in that outside and within the range of the navigational control station an undefined area (55) is created that essentially defines two areas, which at a point of time have magnetic fields essentially opposed to each other.

15. Method according to claim 14, wherein the second current corresponds to the third current.

16. Method according to claim 14, wherein the direction of the magnetic fields generated in the second and third areas depend on the properties of the sent currents.

17. Method according to claim 1 characterised in that at least one current in the system constitutes a sinus component.

18. Method according to claim 1 characterised in that at least one current sent in the system most of the time is in a state of rest when it is mainly constant, whereby periodically the state of rest is interrupted by at least one characteristic reference current pulse (7,9,11).

19. Method according to claim 18 characterised in that the sensing unit (14,15,16), knowing the properties of the reference pulse (7), adapts the time intervals within which the sensing unit (14,15,16) sense magnetic fields.

20. Method according to claim 19 characterised in that adaptation means that the sensing unit (14,15,16) synchronises the unit'"'"'s (14,15,16) working frequency in the time domain based on the reference current pulse (7).

21. Method according to claim 19 characterised in that adaptation means that the sensing unit (14,15,16) synchronises the properties of the time intervals in the time domain based on the properties of the reference current pulse (7,9,11).

22. Method according to claim 18 characterised in that each signal generator (1) in the navigational control system synchronises its sent current pulses (7,9,11) with the other current pulses (7,9,11) in the system so that no current pulses (7,9,11) coincide at the same time during the same signal period (8).

23. Electronic navigational control system for a self-propelling device (5), the system comprising at least one navigational control station (3) with at least one loop (4) connected to at least one signal generator (1) and a sensing unit (14,15,16) arranged at the self-propelling device (5), whereby the sensing unit (14,15,16) senses at least one time and space varying and in the air medium propagating magnetic field, at least transmitted via the at least one loop (4),in turn re-transmitting at least one, by the sensing unit (14,15,16) processed, signal to at least one driving source that contributes to the device'"'"'s movements across an area, the system comprises means by which the signal generator (1) sends a current through the at least one loop (4), the current generating the time and space varying magnetic field (43,44,52,54), whereby the sensing unit (14,15,16) comprises means by which the device (5) is maneuvered based on the properties of the sensed magnetic field (43,44,52,54), characterised in that that said sensed magnetic field (43,44,52,54), in an area enclosed by said loop (4), at least at one point of time has different directions (50,51).

24. Electronic navigational control system according to claim 23 characterised in that at least one current being sent in the system during the main part of the time is in a state of rest, where it is essentially constant, whereby the state of rest is periodically interrupted by at least one characteristic reference current pulse (7,9,11).

25. Electronic navigational control system according to claim 23 characterised in that the navigational control station (3) comprises a first loop (6) which surrounds a first area, said loop extends in one plane.

26. Electronic navigational control system according to claim 25 characterised in that the navigational control station (3) comprises a second and a third loop (4), whereby the second loop (4) surrounds a second area and the third loop (4) surrounds a third area.

27. Electronic navigational control system according to claim 26 characterised in that the respective loop (4,6) extends in one plane.

28. Electronic navigational control system according to claim 25 characterised in that the plane extends parallel to the ground surface or vertical to the ground surface.

29. Electronic navigational control system according to claim 25 characterised in that at least one loop constitutes an electric conductor that is placed above, in or below the continuous surface across which the device is intended to move.

30. Electronic navigational control system according to claim 25 characterised in that at least one loop constitutes a continuous electric conductor that is wound in more than one turn.

31. Electronic navigational control system according to claim 30 characterised in that the electric conductor constitutes a fix guide path placed on a carrier.

32. Electronic navigational control system according to claim 23 characterised in that by a self-propelling device (5) is meant an operating robot comprising a operating system for working on the surface across which the robot is moving.

33. Electronic navigational control system according to claim 32 characterised in that the operating system is controlled based on information received and/or stored for processing by the sensing unit (14,15,16).

34. Electronic navigational control system according to claim 32 characterised in that the robot constitutes a lawn-mowing robot, whereby the operating system constitutes knives which, when moving, cut off the biological material growing on the surface.

35. Electronic navigational control system according to claim 32 characterised in that the robot constitutes a vacuum cleaning robot, whereby the operating system comprises the parts with which a vacuum cleaning robot is normally equipped for cleaning the surface from dirt, for instance a rotating brush and a suction device.

36. Electronic navigational control system according to claim 32 characterised in that the robot constitutes a cleaning robot, whereby the operating system comprises the parts with which a cleaning robot is normally equipped for cleaning the surface from dirt, for instance tools for wet-cleaning.