Method and Control System for Controlling a Wired Vehicle Fleet

Abstract

A wired vehicle fleet having a first vehicle connected with a supply unit by a first bendable connection element and a second vehicle connected with the supply unit by a second bendable connection element is controlled by a control unit to avoid a collision between the first and the second bendable connection elements.

Claims

1. A method for controlling a wired vehicle fleet, the vehicle fleet comprising a first vehicle connected with a supply unit by a first bendable connection element and a second vehicle connected with the supply unit by a second bendable connection element, the method comprising: determining a minimum and a maximum height of the first bendable connection element; determining a minimum and a maximum height of the second bendable connection element; determining a first wayline of the first vehicle; and determining a second wayline of the second vehicle depending on the heights of the first and second bendable connection elements.

2. The method of claim 1, wherein the second wayline runs between the first wayline and a location of the supply unit if the minimum height of the first bendable connection element is higher than the maximum height of the second bendable connection element; and wherein the first wayline runs between the second wayline and the location of the supply unit if the maximum height of the first bendable connection element is lower than the minimum height of the second bendable connection element.

3. The method of claim 1, further comprising determining a third wayline of the supply unit, wherein the location of the supply unit is defined by the third wayline.

4. A method for controlling a wired vehicle fleet, the vehicle fleet comprising a first vehicle connected with a supply unit by a first bendable connection element and a second vehicle connected with the supply unit by a second bendable connection element, the method comprising: determining a first wayline of the first vehicle; determining a second wayline of the second vehicle; determining a first safety zone in consideration of a length of the first bendable connection element and a minimum and a maximum height of the first bendable connection element; determining a second safety zone in consideration of a length of the second bendable connection element and a minimum and a maximum height of the second bendable connection element; anticipating variations of the first safety zone based on anticipated variations of the first vehicle moving along the first wayline; anticipating variations of the second safety zone based on anticipated variations of the second vehicle moving along the second wayline; anticipating a collision of the first bendable connection element with the second bendable connection element if an anticipated variation of the first safety zone intersects an anticipated variation of the second safety zone.

5. The method of claim 4, further comprising: determining a third wayline of the supply unit; and anticipating variations of the first safety zone and the second safety zone based on anticipated positions of the supply unit moving along the third wayline.

6. The method of claim 5, further comprising determining an alternative wayline of the supply unit if a collision of the first bendable connection element with the second bendable connection element is anticipated.

7. The method of claim 4, further comprising determining an alternative wayline of the second vehicle if a collision of the first bendable connection element with the second bendable connection element is anticipated.

8. The method of claim 4, further comprising: if a collision of the first bendable connection element with the second bendable connection element is anticipated, performing the following steps: determining a minimum and a maximum height of the first bendable connection element; determining a minimum and a maximum height of the second bendable connection element; determining a first wayline of the first vehicle; and determining a second wayline of the second vehicle depending on the heights of the first and second bendable connection element.

9. The method of claim 4, further comprising adjusting the height of the first or the second bendable connection element.

10. The method of claim 4, wherein the first safety zone is determined in consideration of a size of the first vehicle; and the second safety zone is determined in consideration of a size of the second vehicle.

11. A control system for controlling a wired vehicle fleet, the control system comprising: a supply unit; a first vehicle connected with the supply unit by a first bendable connection element; a second vehicle connected with the supply unit by a second bendable connection element; and a control unit configured to determine a minimum and a maximum height of the first bendable connection element; determine a minimum and a maximum height of the second bendable connection element; determine a first wayline of the first vehicle; and determine a second wayline of the second vehicle depending on the heights of the first and second bendable connection element.

12. The control system of claim 11, further comprising a floating unit for carrying the first or the second bendable connection element in the air.

13. The control system of claim 12, wherein the control unit is configured to determine the maximum height of the first or the second bendable connection element in consideration of a floating height of the floating unit and a size of the floating unit.

14. The control system of claim 12, wherein the floating unit comprises an envelope for enclosing a gas volume.

15. The control system of claim 11, wherein the first or the second bendable connection element is a pipe for supplying a fluid.

16. The control system of claim 11, wherein at least one of the first vehicle, the second vehicle and the supply unit comprises a height variable mast for connecting the first or the second bendable connection element.

17. The control system of claim 16, the first vehicle comprising a first height variable mast connected with the first bendable connection element for adjusting the maximum height of the first bendable connection element; the second vehicle comprising a second height variable mast connected with the second bendable connection element for adjusting the maximum height of the second bendable connection element; and wherein the control unit is configured to adjust the maximum height of each of the first and second bendable connection elements so that the maximum height of the bendable connection element of the one of the first and second vehicle being closer to the supply unit is below the minimum height of the bendable connection element of the other vehicle being more distant from the supply unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Several aspects of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0042] FIG. 1 illustrates a control system for controlling a wired vehicle fleet.

[0043] FIG. 2 illustrates a control system for controlling a wired vehicle fleet with safety zones covering bendable connection elements.

[0044] FIG. 3 illustrates a control system for controlling a wired vehicle fleet with a moveable supply unit.

[0045] FIG. 4 illustrates a control system for controlling a wired vehicle fleet with safety zones covering bendable connection elements fixed to carrier ropes.

[0046] FIG. 5 is a simplified view of an agricultural vehicle as part of the vehicle fleet.

[0047] FIG. 6 illustrates simplified view of a control unit.

[0048] FIG. 7 illustrates a control system for controlling a wired vehicle fleet with safety zones covering bendable connection elements and floating units.

[0049] FIG. 8 illustrates a control system for controlling a wired vehicle fleet with safety zones covering UAVs, bendable connection elements and floating units.

[0050] FIG. 9 illustrates a flow diagram for a first method.

[0051] FIG. 10 illustrates a flow diagram for a second method.

DETAILED DESCRIPTION

[0052] FIG. 1 and FIG. 2 show a control system 1 for controlling a wired vehicle fleet 2 comprising a supply unit 3a, a first vehicle 4 connected with the supply unit 3a by a first bendable connection element 6 and a second vehicle 5 also connected with the supply unit 3a by a second bendable connection element 7. The first vehicle 4 and the second vehicle 5 of the vehicle fleet 2 are operating in an agricultural field 8. The first vehicle 4 moves along a wayline 16 and the second vehicle 5 moves along a wayline 17. At the end of the waylines 16 and 17 the first vehicle 4 and the second vehicle 5 may turn in a headland 13 of the agricultural field 8 so that the first vehicle 4 will continue to move along a first wayline 9 and the second vehicle 5 will continue to move along a second wayline 10.

[0053] The supply unit 3a is a stationary entity such as a container. The supply unit 3a is placed at a corner of the agricultural field 8 so that the first and the second vehicle 4 and 5 can easily pass the stationary supply unit 3a when moving along their waylines in the agricultural field 8.

[0054] While the first and second vehicles 4 and 5 are operating in the agricultural field 8 the first and second vehicles 4 and 5 stay connected with the supply unit 3a by their first and second bendable connection elements 6 and 7. The lengths 28 and 29 of the first and the second bendable connection element 6 and 7 may be adjustable to prevent a break of the bendable connection elements 6 and 7 when the first and second vehicle 4 and 5 are getting away from the supply unit 3a. For example, the supply unit 3a may comprise a winch 22 for the bendable connection element 6 and a winch 23 for the bendable connection element 7 to adjust separately the lengths 28 and 29 by unwinding or winding up of the bendable connection elements 6 and 7.

[0055] As can be seen in FIG. 2, one end of the first bendable connection element 6 is connected to the winch 22 and the other end of the first bendable connection element 6 is connected to a distal end 24 of a height variable mast 18 of the first vehicle 4 (see also FIG. 5). Analogously, one end of the second bendable connection element 7 is connected to the winch 23 and the other end of the first second bendable connection element 7 is connected to a distal end 24 of a height variable mast 18 of the second vehicle 5 (see also FIG. 5). The heights of the winch 22 and winch 23 are adjustable, too. Hence, the height of the first and the second bendable connection element 6 and 7 are adjustable by adjusting the height of the corresponding mast 18 or the winch 22, 23.

[0056] The first bendable connection element 6 as well as the second bendable connection element 7 may comprise each a slack 19. The slack 19 may depend on the corresponding lengths 28 and 29 between the one end and the other end of the first and second bendable connection element 6 and 7.

[0057] The first bendable connection element 6 may be covered by a first safety zone 20 and the second bendable connection element 7 may be covered by a second safety zone 21 as explained later on.

[0058] Crop 32 growing on the agricultural field 8 may be treated by the first vehicle 4 and the second vehicle 5 such as spraying, weeding or mowing between the rows of crop 32.

[0059] FIG. 3 and FIG. 4 show also a control system 1 for controlling a wired vehicle fleet 2 comprising a supply unit 3b, a first vehicle 4 connected with the supply unit 3b by a first bendable connection element 6 and a second vehicle 5 also connected with the supply unit 3b by a second bendable connection element 7.

[0060] The control system 1 of FIG. 3 and FIG. 4 may be the same as of FIG. 1 and FIG. 2 except for the stationary supply unit 3a. In contrast to the stationary supply unit 3a, the supply unit 3b shown in FIG. 3 and FIG. 4 is a movable entity such as a vehicle. For example, the supply unit 3b may be a vehicle of the same type as the first or the second vehicle 4 or 5. I.e., the vehicle fleet 2 shown in FIG. 3 and FIG. 4 comprises three agricultural vehicles which may operate in a cooperative manner in the agricultural field 8.

[0061] The supply unit 3a illustrated in FIG. 1 and FIG. 2 as well as the supply unit 3b illustrated in FIG. 3 and FIG. 4 may comprise the same components as for example a energy storage and a tank for resources needed for the field operation. The energy storage may be a battery for storing electrical energy. The tank may comprise several tanks for example to store fuel for propelling the vehicles of the vehicle fleet 2 or agents such as fertilizers or pesticides to be dispensed on crops of the agricultural field 8 by the vehicles of the vehicle fleet 2. The electrical energy and the resources may be transferred from the supply unit 3a or 3b to the first and second vehicle 4 and 5 through the corresponding first and second bendable connection elements 6 and 7 the first and second vehicle 4 and 5 are connected with.

[0062] The first and the second bendable connection element 6 and 7 may comprise a wire, a pipe or both for transferring the electrical energy or the resources. The wire may also be used to transfer data or signals between the supply unit 3a, 3b and the vehicles 4, 5.

[0063] As shown in FIG. 3, the first vehicle 4 moves along a wayline 16 and the second vehicle 5 moves along a wayline 18 analogously to FIG. 1. Additionally, the supply unit 3b moves along a wayline 35. At the end of the waylines 16, 17 and 35, the first vehicle 4, the second vehicle 5 and the supply unit 3b may turn in a headland 13 of the agricultural field 8 so that the first vehicle 4 will continue to move along a first wayline 9, the second vehicle 5 will continue to move along a second wayline 10 and the supply unit 3b will continue to move along a third wayline 33.

[0064] Irrespectively that the winch 22 and winch 23 are connected with the moveable supply unit 3b instead of the supply unit 3a the heights of the first and second bendable connection element 6 and 7 are adjustable in an analogous manner as described above. But in contrast to FIG. 2, the first and the second bendable connection element 6 and 7 are fixed each to a carrier rope 36 by several fixations 37 to reduce the slack 19. (The control system 1 according to FIG. 1 and FIG. 2 may also be equipped with carrier ropes 36).

[0065] FIG. 5 shows an agricultural vehicle 38 connected with an implement 39 such as a mower to harvest or cut crop 32. The agricultural vehicle 38 may be of any type such as an agricultural robot, a tractor, a harvester, etc. The agricultural vehicle 38 may represent at least one of the first vehicle 4, the second vehicle 5 and the supply unit 3b. The agricultural vehicle 38 comprises a roof 41 on which a height variable mast 18 is mounted. A distal end 24 of the mast 18 is connected with the first bendable connection element 6 or the second bendable connection element 7. The height variable mast 18 may comprise a telescopic extendable element to raise or lower the distal end 24 of the mast 18 to adjust the height of the first or the second bendable connection element 6 or 7. As shown in FIG. 5, a carrier rope 36 may be optionally connected to the mast 18. The first or the second bendable connection element 6 or 7 may be connected to the carrier rope 36 by one or more fixations 37 for reducing a slack 19 of the bendable connection element. The more fixations 37 are used to connect the bendable connection element 6, 7 to the carrier rope 36 the more the slack 19 may be reduced.

[0066] At least one of the supply unit 3a, 3b, the first and the second vehicle 4 and 5 comprises a control unit 40. The control unit 40 may be integrated in the supply unit 3a shown in FIG. 1. The control unit 40 may be integrated in the agricultural vehicle 38 representing the supply unit 3b as shown in FIG. 3, FIG. 4 and FIG. 5. Alternatively, control unit 40 may be integrated in any of the first and second vehicle 4 and 5. More alternatively, the control unit 40 may be provided beyond supply unit 3a, 3b, the first and the second vehicle 4 and 5 and communicate with supply unit 3a, 3b, the first and the second vehicle 4 and 5 via cellular network or any other wireless communication.

[0067] FIG. 6 shows the control unit 40 comprising an interface 42, a controller 43 and a memory 44. The control unit 40 may receive and send signals or data via the interface 42. The interface 42 may be a wireless interface or a connector. The interface 42 may additionally be provided to communicate wirelessly to further stationary or mobile devices to enable monitoring or planning of the wired vehicle fleet 2 by a human operator. The controller 43 may store the data or signals received by the control unit 40 in the memory 44. The memory 44 may contain additional data or executable programs, for example in terms of a computer-implemented method, that may be retrieved, processed or carried out by the controller 43. Data or signals resulting from the processing of data or signals or from the execution of a program may be stored to the memory 44 or sent to the interface 42 by the controller 43.

[0068] The first bendable connection element 6 and the second bendable connection element 7 may be connected to the interface 42 of the control unit 40. The control unit 40 may communicate with the first vehicle 4 and the second vehicle 5 through the corresponding bendable connection elements 6 and 7. Thus, the control unit 40 may control the vehicle speed or the steering of the first and the second vehicle 4 and 5 to move the first and the second vehicle 4 and 5 along their waylines. The control unit 40 may also control the implement 39 of the first and the second vehicle 4 and 5. In case of a moveable supply unit 3b the control unit 40 may also control the vehicle speed or the steering of the supply units 3b as well as any implement 39 connected to the supply unit 3b.

[0069] FIG. 7 shows the same control system 1 as shown in FIG. 4 wherein the first bendable connection element 6 and the second bendable connection element 7 are additionally equipped with at least one floating unit 45 for carrying the bendable connection elements in the air. The floating units 45 may be fixed to the fixations 37 and may comprise an envelope to enclose a gas volume. The gas volume may comprise a gas lighter than air as for example helium to provide a buoyancy force. The floating unit 45 may be of the same type and may have the same functionality as the floating unit described in the GB patent application, application number 2205518.0, mentioned above.

[0070] FIG. 8 shows a control system 1 similar to FIG. 7 wherein drones (unmanned aerial vehicles) are operating as first and second vehicle 4 and 5. I.e. in contrast to ground-based agricultural vehicles, the drones may fly over the agricultural field 8 to treat the crop 32 and may vary their altitudes. The height of the winch 22 and winch 23 may be adjusted to the corresponding altitude of the first and second vehicle 4 and 5.

[0071] FIG. 9 shows a flow diagram of a first method M1. The method M1 may be a computer implemented method and may be carried out by the control unit 40. The method M1 may be part of a wayline planning for vehicle fleet 2 prior to moving on agricultural field 8. The method M1 may be started before one of the moveable supply unit 3b, the first and the second vehicle 4 and 5 approaches the headland 13 of the agricultural field 8. The method M1 works with each control system 1 as shown in FIG. 2, FIG. 4, FIG. 7 and FIG. 8. The method M1 starts with step S100 and proceeds to step S101 for determining a minimum and a maximum height of the first bendable connection element 6. The control unit 40 may determine the height 30 of the distal end 24 of the mast 18 of the first vehicle 4 to determine the maximum height of the first bendable connection element 6. The minimum height may be determined by the slack 19 of the first bendable connection element 6 by the control unit 40. The slack 19 may be calculated by the control unit 40 based on a length of the bendable connection element. The minimum height of the first bendable connection element 6 may be a predefined parameter stored in the memory 44 and retrieved by the control unit 40.

[0072] The method proceeds to step S102 for determining a minimum and a maximum height of the second bendable connection element 7. The control unit 40 may determine the minimum and the maximum height of the second bendable connection element 7 based on the height 31 of the distal end 24 of the mast 18 of the second vehicle 5 and the slack 19 of the second bendable connection element 7 analogously to the determination of the first bendable connection element 6 as described above.

[0073] The method proceeds to step S103 and the control unit 40 determines a first wayline 9 of the first vehicle 4. As can be seen in FIG. 1 or FIG. 3, the first wayline 9 may be a straight line through the agricultural field 8 and may be parallel to at least one other wayline. The first wayline 9 may be stored in the memory 44 or may be transferred to the first vehicle 4 for guiding the first vehicle 4 along the first wayline 9. Alternatively, the control unit 40 may determine control signals for guiding the first vehicle 4 along the first wayline 9 and may send the control signals to the first vehicle 4. Thus, the first vehicle 4 may travel autonomously along the first wayline 9 for an automated field operation.

[0074] In case of a moveable supply unit 3b the method may proceed to step S104. Otherwise the method proceeds to step S105 and S106 or S107 to determine a second wayline of the second vehicle 5.

[0075] At step S104, the control unit 40 may determine a third wayline 33 for the moveable supply unit 3b. As can be seen in FIG. 3, the third wayline 33 may be a straight line through the agricultural field 8 and may be parallel to at least one other wayline, e.g. the first wayline 9. The third wayline 33 may be stored in the memory 44. The control unit 40 may determine control signals for guiding the supply unit 3b along the third wayline 33 and may control the moveable supply unit 3b accordingly. Thus, the supply unit 3b may travel autonomously along the third wayline 33 for an automated field operation.

[0076] The method proceeds to step S105 and the control unit 40 determines whether the minimum height of the first bendable connection element 6 is higher than the maximum height of the second bendable connection element 7 (first option) or whether the minimum height of the second bendable connection element 7 is higher than the maximum height of the first bendable connection element 6 (second option). Then, the control unit 40 determines a second wayline 10 of the second vehicle 5 depending on the heights of the first and second bendable connection element 6 and 7 so that the first and the second bendable connection elements 6 and 7 won't collide against each other when the first vehicle 4 and the second vehicle 5 travel along their corresponding first and second waylines 9 and 10.

[0077] In case of the first option, the method proceeds to step S106 and a wayline extending between the first wayline 9 and the position of the supply unit 3a, 3b will be determined as the second wayline 10 by the control unit 40 as shown in FIG. 1 or FIG. 3. In case of the second option, the method proceeds to step S107 and a wayline extending next to the first wayline 9 but having a greater distance from the supply unit 3a, 3b than the first wayline 9 will be determined as the second wayline 10 by the control unit 40. Thus, the vehicle connected with the bendable connection element having the lower height is guided closer to the supply unit 3a, 3b than the other vehicle connected with the bendable connection element having the greater height.

[0078] As can be seen in FIG. 3, the position of the moveable supply unit 3b may be the current position of the supply unit 3b. Alternatively, the position of the moveable supply unit 3b may be defined by the third wayline 33 determined at step S104 and may be an anticipated position 34 of the supply unit 3b.

[0079] As can be seen in FIG. 1 or FIG. 3, the second wayline 10 may be a straight line through the agricultural field 8 and may be parallel to at least one other wayline, e. g. the first wayline 9. The second wayline 10 may be stored in the memory 44 or may be transferred to the second vehicle 5 for guiding the second vehicle 5 along the second wayline 10. Alternatively, the control unit 40 may determine control signals for guiding the second vehicle 5 along the second wayline 10 and may send the control signals to the second vehicle 5. Thus, the second vehicle 5 may travel autonomously along the second wayline 10 for an automated field operation.

[0080] After step S106 or S107, the method proceeds to step S108 and the first method M1 ends. Finally, the control unit 40 determined a first and a second wayline 9 and 10 for the first and second vehicle 4 and 5 which enable a travel of the first and the second vehicle 4 and 5 through the agricultural field 8 without a collision between the first bendable connection element 6 and the second bendable connection element 7.

[0081] Optionally, the first method M1 may be carried out by control unit 40 which may be beyond supply unit 3a, 3b, the first and the second vehicle 4 and 5 to enable off-board wayline planning. The wayline plan may then be communicated to vehicle fleet 2.

[0082] FIG. 10 shows a flow diagram of a second method M2. The method M2 may be a computer implemented method and may be carried out by the control unit 40. The method M2 works with each control system 1 as shown in FIG. 2, FIG. 4, FIG. 7 and FIG. 8. The method M2 starts with step S200 and proceeds to step S201 for determining a first wayline 9 of the first vehicle 4. The first wayline 9 may be determined by the control unit 40 analogously to step S103 of method M1.

[0083] The method M2 may be part of a collision avoidance system. The first and second waylines 9, 10 may be part of a predetermined wayline planning. The waylines may change during operation, e. g. if the vehicles 4 and 5 are provided with means for obstacle detection and a detected obstacle such as a stone or a tree forces the vehicles 4 or 5 to leave the predetermined wayline.

[0084] The method proceeds to step S202 and the control unit 40 determines a second wayline 10 of the second vehicle 5. The second wayline 10 be determined by the control unit 40 analogously to step S106 or S107 of method M1.

[0085] The method proceeds to step S203 and the control unit 40 determines a first safety zone 20 in consideration of a length 28 of the first bendable connection element 6 and a minimum and a maximum height of the first bendable connection element 6 as can be seen in FIG. 2 and FIG. 4. The length 28 of the first bendable connection element 6 depends on the distance between the first vehicle 4 and the supply unit 3a, 3b as it is apparent from FIG. 1 to FIG. 4. Since the distance between the first vehicle 4 and the supply unit 3a, 3b may vary the length 28 of the first bendable connection element 6 may vary accordingly. The minimum height of the first bendable connection element 6 depends on the slack 19 of the first bendable connection element 6 as can be seen in FIG. 2 and FIG. 4. The slack 19 may be reduced if the first bendable connection element 6 is attached to the carrier rope 36 by at least a fixation 37 as can be seen in FIG. 4 and FIG. 5. The maximum height of the first bendable connection element 6 may depend on the height 30 of the distal end 24 of the mast 18 of the first vehicle 4 as can be seen in FIG. 2 and FIG. 4. Since the height of the height variable mast 18 is adjustable the maximum height of the first bendable connection element 6 may vary accordingly. The maximum height of the first bendable connection element 6 may depend on the height of the winch 22 of the first bendable connection element 6. Alternatively, the maximum height of the first bendable connection element 6 may depend on a floating height of at least one floating unit 45 attached to the first bendable connection element 6 as can be seen in FIG. 7 and FIG. 8. Thus, the first safety zone 20 determined by the control unit 40 covers the first bendable connection element 6 completely and reaches from the winch 22 of the first bendable connection element 6 to the mast 18 of the first vehicle 4 and from the maximum height to the minimum height of the first bendable connection element 6. So for simplicity, the first safety zone 20 may be shaped as a cuboid. Alternatively, the first safety zone 20 may be determined as a tube or any other solid surrounding the first bendable connection element 6.

[0086] The method proceeds to step S204 and the control unit 40 determines a second safety zone 21 in consideration of a length 29 of the second bendable connection element 7 and a minimum and a maximum height of the second bendable connection element 7 as can be seen in FIG. 2 and FIG. 4. The second safety zone 21 may be determined analogously to the first safety zone 20. The length 29 of the second bendable connection element 7 depends on the distance between the second vehicle 5 and the supply unit 3a, 3b as it is apparent from FIG. 1 to FIG. 4. Since the distance between the second vehicle 5 and the supply unit 3a, 3b may vary the length 29 of the second bendable connection element 7 may vary accordingly. The minimum height of the second bendable connection element 7 depends on the slack 19 of the second bendable connection element 7 as can be seen in FIG. 2 and FIG. 4. The slack 19 may be reduced if the second bendable connection element 7 is attached to the carrier rope 36 by at least a fixation 37 as can be seen in FIG. 4 and FIG. 5. The maximum height of the second bendable connection element 7 may depend on the height 31 of the distal end 24 of the mast 18 of the second vehicle 5 as can be seen in FIG. 2 and FIG. 4. Since the height 31 of the height variable mast 18 is adjustable the maximum height of the second bendable connection element 7 may vary accordingly. The maximum height of the second bendable connection element 7 may depend on the height of the winch 23 of the second bendable connection element 7. Alternatively, the maximum height of the second bendable connection element 7 may depend on a floating height of at least one floating unit 45 attached to the second bendable connection element 7 as can be seen in FIG. 7 and FIG. 8. Thus, the second safety zone 21 determined by the control unit 40 covers the second bendable connection element 7 completely and reaches from the winch 23 of the second bendable connection element 7 to the mast 18 of the second vehicle 5 and from the maximum height to the minimum height of the second bendable connection element 7. So for simplicity, the second safety zone 21 may be shaped as a cuboid. Alternatively, the second safety zone 21 may be determined as a tube or any other solid surrounding the second bendable connection element 7.

[0087] While the first and the second vehicle 4 and 5, and optionally the supply unit 3b, travel along their waylines 9, 10 and 33 the bendable connection elements 6 and 7 will change their positions. E. g., the first bendable connection element will change its position as indicated by numeral 14 when the first vehicle 4 arrives a vehicle position 11 and the second bendable connection element 7 will change its position as indicated by numeral 15 when the second vehicle 5 arrives a vehicle position 12 (see FIG. 1 and FIG. 3). In addition, the position of the first and second bendable connection elements 6 and 7 depend on the position of the supply unit 3a, 3b regardless whether the supply unit 3a, 3b changes its position, e. g. to a position indicated by numeral 34 (see FIG. 3) or not.

[0088] These positional changes of the first and second bendable connection elements 6 and 7 may affect the lengths 28 and 29 and the maximum and the minimum heights of the first and second bendable connection elements 6 and 7 resulting in different variations of the first safety zone 20 of the first bendable connection element 6 and in different variations of the second safety zone 21 of the second bendable connection element 7. As can be seen in FIG. 2 or FIG. 4 for example, if the first vehicle 4 travels from the wayline 16 to the anticipated position 11 the length 28 of the first bendable connection element 6 will be extended as indicated by the bendable connection element 14. Consequently, the first safety zone 20 will be extended to the safety zone 20* to cover the first bendable connection element 6 extended to the bendable connection element 14. I. e., a variation of the first safety zone 20 is defined by the extended safety zone 20*.

[0089] Thus, the control unit 40 updates the first and second safety zones 20 and 21 in dependence of the different positions of the supply unit 3b and the first and second vehicle 4 and 5 and determines the corresponding variations of the first and second safety zone 20 and 21 for the different positions.

[0090] The method proceeds to step S205 and the control unit 40 anticipates variations of the first safety zone 20 based on anticipated positions 11 of the first vehicle 4 moving along the first wayline 9 (see FIG. 1 to FIG. 4. The anticipated positions 11 of the first vehicle 4 may be determined by the control unit 40 based on the current position of the first vehicle 4, the first wayline 9, the driving speed of the first vehicle 4 and the operation time of the vehicle fleet 2. Then, the anticipated variations of the first safety zone 20 may be determined by the control unit 40 based on the changes of the length 28 and the maximum and the minimum height of the first bendable connection element 6 affected by the anticipated positions 11 of the first vehicle 4.

[0091] The method proceeds to step S206 and the control unit 40 anticipates variations of the second safety zone 21 based on anticipated positions 12 of the second vehicle 5 moving along the second wayline 10 analogously to step S205 (see FIG. 1 to FIG. 4). The anticipated positions 12 of the second vehicle 5 may be determined by the control unit 40 based on the current position of the second vehicle 5, the second wayline 10, the driving speed of the second vehicle 5 and the operation time of the vehicle fleet 2. Then, the anticipated variations of the second safety zone 21 may be determined by the control unit 40 based on the changes of the length 29 and the maximum and the minimum height of the second bendable connection element 7 affected by the anticipated positions 12 of the second vehicle 5.

[0092] In case of a moveable supply unit 3b (see FIG. 3 and FIG. 4), anticipated positions 34 of the supply unit 3b are needed to be taken into account for the anticipation of the first and second safety zones 20 and 21 since these anticipated positions 34 may also affect the lengths 28 and 29 and the maximum and the minimum heights of the first and the second bendable connection element 6 and 7. Thus, the method proceeds optionally to step S207 and the control unit 40 optionally determines a third wayline 33 of the supply unit 3b and anticipates variations of the first safety zone 20 and the second safety zone 21 based on anticipated positions 34 of the supply unit 3b moving along the third wayline 33. The anticipated positions 34 of the supply unit 3b may be determined by the control unit 40 based on the current position of the supply unit 3b, the third wayline 33, the driving speed of the supply unit 3b and the operation time of the vehicle fleet 2.

[0093] Then, the method proceeds to step S208 and the control unit 40 anticipates a collision of the first bendable connection element 6 with the second bendable connection element 7 if an anticipated variation of the first safety zone 20 intersects an anticipated variation of the second safety zone 21. As can be seen in FIG. 2 and FIG. 4 for example, the first safety zone 20 intersects the second safety zone 21 within a collision zone 27 indicating a collision at the same operation time of the vehicle fleet 2.

[0094] If a collision is anticipated at step S208, the method proceeds to step S209 and the control unit 40 executes at least one preventive measure to avoid the anticipated collision. For example, a preventive measure may be a determination of an alternative wayline of the movable supply unit 3b. Another preventive measure may be a determination of an alternative wayline of the second vehicle 5. Another preventive measure may be to carry out at least one of the steps S100 to S108 of the first method M1.

[0095] The method may optionally proceed to step S210 and the control unit 40 may optionally adjust the height of the first or the second bendable connection element 6 or 7. Step S210 may also be executed as a preventive measure to avoid an anticipated collision. The height of the first or second bendable connection element 6 or 7 can be adjusted by an adjustment of the heights 30 or 31 of the variable mast 18 or by an adjustment of the height of the winch 22 or winch 23. So, the control unit 40 may adjust the height of the first and second bendable connection element 6 or 7 such that the maximum height of the bendable connection element connected with the vehicle being guided closer to the supply unit 3a, 3b is lower than the minimum height of the bendable connection element connected with the other vehicle being guided with a greater distance from the supply unit 3a, 3b.

[0096] When the first safety zone 20 is determined by the control unit 40 at step S203 and when the second safety zone 21 is determined by the control unit 40 at step S204 the control unit 40 may optionally consider the size of the first vehicle 4 with respect to the first safety zone 20 and the size of the second vehicle 5 with respect to the second safety zone 21. Thus, the first vehicle 4 may be covered by the first safety zone 20 extended with safety zone 25 and the second vehicle 5 may be covered by the second safety zone 21 extended with safety zone 26. The extended safety zones 25 and 26 may encompass the first and the second vehicle 4 and 5 irrespective of the type of the first and the second vehicle 4 and 5 so that ground-based agricultural vehicles (see FIG. 2, FIG. 4, FIG. 7) may be encompassed as well as drones (see FIG. 8). I. e., the first and the second safety zones 20 and 21 is not restricted to the first and second bendable connection elements 6 and 7 only.

[0097] If a collision couldn't be anticipated by the control unit 40 at step S208, the method proceeds to step S211. Finally, the second method M2 ends with step S211.

[0098] Both methods M1 and M2 enable the control system 1 to provide a (predictive) wayline plan for collision free travel of the wired vehicle fleet 2 in agricultural field 8 and also enable to avoid collision during the operation of the wired vehicle fleet 2 (with or without a predetermined wayline plan).

[0099] All references cited herein are incorporated herein in their entireties. If there is a conflict between definitions herein and in an incorporated reference, the definition herein shall control.

LISTING OF DRAWING ELEMENTS

[0100] 1 control system [0101] 2 vehicle fleet [0102] 3a supply unit [0103] 3b supply unit [0104] 4 first vehicle [0105] 5 second vehicle [0106] 6 first bendable connection element [0107] 7 second bendable connection element [0108] 8 agricultural field [0109] 9 first wayline [0110] 10 second wayline [0111] 11 anticipated position [0112] 12 anticipated position [0113] 13 headland [0114] 14 bendable connection element [0115] 15 bendable connection element [0116] 16 wayline [0117] 17 wayline [0118] 18 mast [0119] 19 slack [0120] 20 first safety zone [0121] 21 second safety zone [0122] 22 winch [0123] 23 winch [0124] 24 distal end [0125] 24 first safety zone (extended) [0126] 26 second safety zone (extended) [0127] 27 collision zone [0128] 28 length [0129] 29 length [0130] 30 height [0131] 31 height [0132] 32 crop [0133] 33 third wayline [0134] 34 anticipated position [0135] 35 wayline [0136] 36 carrier rope [0137] 37 fixation [0138] 38 agricultural vehicle [0139] 39 implement [0140] 40 control unit [0141] 41 roof [0142] 42 interface [0143] 43 controller [0144] 44 memory [0145] 45 floating unit