Spray unit

Abstract

The present invention relates to a spray unit including a shaft (20), a disk (30), a disk-shape-changing assembly (40), and a liquid applicator (50). The disk is configured to rotate about the shaft centered on the center of the disk. The liquid applicator is configured to apply liquid to a surface of the disk. The disk-shape-changing assembly is configured to change the diameter of the disk, thereby changing the trajectory of liquid droplets leaving the spray unit.

Description

[Technical field]

[0001] The present invention relates to a spray unit and to a vehicle equipped with such a spray unit. [Background technology]

[0002] The application of crop protection products to crops is typically carried out by spray application, where the atomizing device is usually a hydraulic spray nozzle, a rotating disk or a rotating cage, or an air shear device. In order to effectively apply the crop protection product to the leaves of the crop, the characteristics of the atomizing device are very important, in particular the droplet size generated. The range of droplet sizes is known as the droplet spectrum. Fine atomization produces a very large number of small droplets, which leads to a greater coverage in terms of the number of deposits per unit area and in terms of an increased area under the deposit, both of which are favorable in terms of biological effectiveness, whereas coarse atomization produces a relatively small number of larger droplets, which leads to a smaller number of deposits per unit area. However, smaller droplets are prone to drift, resulting in undesirable off-target losses, and generally have poor penetration into the crop cover, both of which can be mitigated by using larger droplets and droplets with greater momentum, but at the cost of reducing the number of opportunities for deposits to form in the crop cover to be treated. However, different parts of the crop field have different requirements for mitigating drift during spray application of the product, for example the downwind end of the crop field has a greater risk of off-target drift outside the spray area compared to the center of the field or compared to the upwind end of the field. Another use case is that different types or sizes of weeds require different droplet sizes, and different agrochemical active ingredients express their effectiveness differently depending on the droplet size. As a result, it is advantageous to be able to continuously adjust the droplet size during application according to the optimal balance between the number of droplets per unit area required for biological performance and the risk of off-target drift. Furthermore, the effect of wind on drift is also important, and in particular the wind is not constant but varies three-dimensionally in time and space, resulting in a continuous change in the optimal balance between droplet numbers per unit area and off-target drift.Therefore, there is a need for a spraying device that can continuously adjust its droplet size according to its position in the target field and the current wind speed and direction, while keeping in mind the biological consequences of such changes in droplet spectrum. For example, under gusty wind conditions, significantly larger droplets may be required at the edge of the field to suppress drift, but this reduces the effectiveness of the active ingredient, so a larger application rate is required in such situations. With hydraulic spray nozzles, it is difficult to achieve these conflicting requirements because in order to obtain different spray droplet spectra, the nozzle must be operated at different pressures or the nozzle must be changed to a different orifice size, both of which take time. However, with a rotating disk, the droplet spectrum can be adjusted almost instantly by changing the rotation speed and the flow rate to the disk independently of each other. However, reducing the rotation speed of the rotating disk, for example on an unmanned aerial vehicle (UAV), has two consequences. First, the droplet size after atomization increases, if necessary, and second, the velocity of the droplets leaving the disk decreases, which reduces the width of the spray cone, especially when contained in the downdraft from the rotor of the UAV or in an air-assisted boom sprayer, thereby reducing the width of the spray swath and making the overlap generated by multiple spray swaths more variable. This is undesirable because it increases the work speed to treat the same area and also creates the risk of creating untreated areas between adjacent swaths, and also creates the risk of overdosing and underdosing. Second, the rotation speed of the rotor, for example on the UAV, during the acceleration / deceleration of the UAV during spraying, and during the mass loss of the UAV as the spray fluid is distributed, affects the amount and speed of the downdraft and subsequently the width of the spray swath.As a result, there is a need for a spraying device that can continuously adjust its droplet spectrum according to its position within the target field, the current wind speed and direction, the downdraft from the UAV rotor and / or the flight height of the UAV, without affecting the width of the spray cone and the width of the spray swath applied. Summary of the Invention

[0003] It would be advantageous to have an improved means for spraying liquids, such as those containing chemical and / or biological agriculturally active ingredients.

[0004] The object of the present invention is solved by the subject matter of the independent claims, further embodiments are incorporated in the dependent claims. It should be noted that the aspects and examples described below with respect to the present invention apply both to the spray unit and to a vehicle having one or more spray units.

[0005] In a first aspect, a spray unit is provided. The spray unit includes a shaft, a disk, a disk shape-changing assembly, and a liquid applicator. The disk is configured to rotate about the shaft centered on a center of the disk. The liquid applicator is configured to apply liquid to a surface of the disk. The disk shape-changing assembly is configured to change a diameter of the disk to thereby change a trajectory of liquid droplets leaving the spray unit.

[0006] In other words, the disk shape changing assembly can change the diameter of the rotating disk, which can change the geographic location where the droplets leave the spray unit towards the ground, and therefore the trajectory of the liquid droplets, thus affecting the spray swath width. As a result, the spray swath width and the liquid droplet size can be independently varied in a manner that can achieve a constant and uniform swath width over a wide range of spray droplet sizes.

[0007] In this way, an optimal application of active ingredient per plant per unit area of ​​land can be provided.

[0008] In one example, the disc shape-changing assembly includes at least one movable shape-defining member configured to change a diameter of the disc or a diameter of the second disc by changing a position of at least a portion of the shape-defining member, and the disc shape-changing assembly includes at least one actuator configured to drive the at least one shape-defining member.

[0009] In other words, the controllable actuator changes the geometry of the disk diameter and therefore the spray swath width, for example depending on weather conditions. Alternatively, the geometry of the diameter of a second disk in close proximity to the rotating disk is changed. Droplets leaving the edge of the rotating disk impinge against the second disk. By changing the geometry of the diameter of the second disk, a similar result can be obtained as when changing the geometry of the diameter of the rotating disk.

[0010] In one example, the disc shape changing assembly includes at least one shape defining member selected from the group consisting of a blade, an elastic film, and a slotted circular disc.

[0011] In one example, the disk shape changing assembly includes at least two blades, each of the at least two blades coupled to the disk or to the second disk via at least one blade pivot point, the at least one actuator configured to be coupled to at least one of the at least two blades via a blade drive link, and the at least two blades configured to be coupled by at least one inter-blade link.

[0012] In other words, all the blades are connected via inter-blade links, so that they can be driven simultaneously by at least one actuator, and thus the diameter of the rotating disc, or the diameter of the second disc, can be varied in a consistent and uniform manner, so that the spray swath width can also be precisely controlled.

[0013] In one example, the disk shape-changing assembly includes a concentric elastic film attached to an edge of the disk or to an edge of a second disk, the disk shape-changing assembly further includes at least two extensible rods, each of the at least two extensible rods being connected to the disk or to the second disk and to the elastic film via at least one rod pivot point, the rods being configured to stretch and relax the elastic film evenly in all radial directions, the at least one actuator being configured to be connected to at least one of the two extensible rods via a rod drive link, and the at least two rods being configured to be connected by at least one inter-rod link.

[0014] In other words, instead of a driven blade as described above, the rotating disk can include an elastic film at the edge of the disk (or the second disk) that is uniformly stretchable to different disk diameter sizes. Control of the stretching of the elastic film is realized via an extensible rod connected to the disk (or the second disk) and to the elastic film. The stretching of the rod is again controlled by at least one actuator.

[0015] In one example, the disk shape-changing assembly includes at least four rods, each of the at least four rods connected to the disk or to the second disk and to the elastic film via at least one rod pivot point, the rods configured to stretch and relax the elastic film evenly in all radial directions, at least one actuator configured to be connected to at least one of the four extendable rods via a rod drive link, and the at least four rods configured to be connected by at least one inter-rod link.

[0016] In one example, the rods are arranged in a substantially radially symmetric arrangement beneath the disc or beneath the second disc.

[0017] In this way, the elastic film can be easily stretched evenly in all radial directions.

[0018] In one example, a second disk is disposed axially below and spaced from the disk.

[0019] In this way it is ensured that the time and distance travelled by the liquid droplets before they leave the edge of the rotating disc and impact the second disc is minimised.

[0020] In one example, the disc shape-changing assembly includes at least one slotted circular disc configured to laterally surround the disc thereby expanding a diameter of the disc, and at least one actuator configured to control a position of the at least one slotted circular disc relative to the disc.

[0021] Another alternative to driven blades and stretchable elastic films is to vary the diameter of the rotating disk by at least one slotted circular disk that can be driven relative to the rotating disk and that can laterally surround the disk to expand the diameter of the disk, again at least one actuator controlling the drive of the at least one slotted disk relative to the rotating disk.

[0022] In one example, the disc shape-changing assembly includes at least two slotted circular discs, a second slotted circular disc of the at least two slotted circular discs configured to laterally surround the first slotted circular disc, and at least one actuator configured to control a position of the second slotted circular disc relative to the first slotted circular disc and / or relative to the discs.

[0023] In other words, more than one slotted circular disk can be provided to have greater flexibility in varying the diameter of the rotating disk.

[0024] In one example, the disk shape-changing assembly is configured to rotate about the shaft or about a second shaft.

[0025] In this way, not only the spray swath width can be influenced by the disk shape changing assembly. By varying the rotation speed of the disk shape changing assembly, the atomization process of the liquid droplets to be sprayed can also be further manipulated, if desired. If there is a second disk rotating about the second axle, the rotation speed of the second disk can be different from the rotation speed of the rotating disk, thereby providing further control of the atomization process of the liquid droplets.

[0026] In one example, the disk shape-changing assembly is non-rotating.

[0027] In one example, at least a portion of the surface of the disk shape change assembly against which the liquid droplets impinge as they leave the outer edge of the disk has a low friction surface.

[0028] In other words, particularly when the disk shape-changing assembly is not intended to rotate and therefore is in a fixed position, at least a portion of the surface of the disk shape-changing assembly against which liquid droplets from the rotating disk impinge can be constructed of a material having very low friction and very low adhesion, such that individual droplets formed from the rotating disk roll over its surface and do not significantly adhere.

[0029] In a second aspect, there is provided a spraying vehicle comprising at least one spraying unit according to the first aspect.

[0030] In one example, the spraying vehicle includes a liquid tank, at least one spraying unit as described above, a plurality of sensors, and a processing unit. The liquid tank is configured to contain a liquid. The at least one spraying unit is configured to spray the liquid. At least one sensor in the plurality of sensors is configured to measure a rotational speed of the disk about an axis centered on a center of the disk. At least one sensor in the plurality of sensors is configured to measure a liquid flow rate from a liquid applicator to a surface of the disk. The processing unit is configured to determine a liquid droplet size of liquid droplets leaving the spraying unit including utilizing the measured rotational speed of the disk, the measured liquid flow rate from the liquid applicator to the disk surface, and physicochemical properties of the liquid. The processing unit is configured to control at least one actuator of the spraying unit, and determining at least one command to control the at least one actuator includes utilizing the determined liquid droplet size.

[0031] In other words, the width of the spray cone and the width of the spray swath dispensed can be maintained constant even though the droplet size is continuously adapted, for example, based on the position of the atomization device within the target field, based on the current wind speed and direction, and / or based on, for example, the downdraft from the UAV rotor and / or the flight height of the UAV.

[0032] Advantageously, any advantage provided by any of the above aspects applies equally to all other aspects, and vice versa.

[0033] The above aspects and examples will be apparent from and elucidated with reference to the embodiments described hereinafter.

[0034] Exemplary embodiments are described below with reference to the following drawings: [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 is a side view showing a schematic configuration of an example of a newly developed spray unit. [Diagram 2] FIG. 2 shows a schematic configuration of an example of a spray unit having a cone-shaped disk in a side view. [Diagram 3] FIG. 3 shows a schematic configuration of an example of a spray unit having a disk shape changing assembly on the second disk in a side view. [Figure 4] FIG. 4 illustrates, in a bottom view, a schematic configuration of an example of a spray unit having a disk shape-changing assembly including a blade. [Diagram 5] FIG. 5 illustrates, in plan view, a schematic configuration of an example of a spray unit having a disk shape-changing assembly including a blade. [Figure 6]FIG. 6 illustrates, in a bottom view, a schematic configuration of another example of a spray unit having a disk shape-changing assembly including a blade. [Figure 7] FIG. 7 illustrates, in plan view, a schematic configuration of another example of a spray unit having a disk shape-changing assembly including a blade. [Figure 8] FIG. 8 illustrates, in bottom view, a schematic configuration of an example of an aerosol unit having a disk shape-changing assembly including an elastic film. [Figure 9] FIG. 9 illustrates, in plan view, a schematic configuration of an example of a spray unit having a disk shape-changing assembly including an elastic film. [Figure 10] FIG. 10 illustrates, in side view, a schematic configuration of an example spray unit having a disk shape changing assembly including a slotted circular disk. [Figure 11] FIG. 11 illustrates, in side view, a schematic configuration of another example of an aerosol unit having a disk shape changing assembly including a slotted circular disk. [Figure 12] FIG. 12 shows a schematic example of a circular slotted disk from different perspectives. [Figure 13] FIG. 13 illustrates, in a side view, a schematic configuration of another example of a spray unit having a disk shape changing assembly including a slotted circular disk and a second shaft. [Figure 14] FIG. 14 illustrates a schematic configuration of an example of a spray vehicle including a spray unit. [Figure 15] FIG. 15 shows a schematic example of a spraying vehicle having a spraying unit and a control member of a disk shape changing assembly. [Figure 16] FIG. 16 shows a schematic example of a spraying vehicle with a spraying unit and a control member of the disk shape changing assembly as a function of different droplet sizes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] FIG. 1 illustrates an example of a spray unit 10 in a side view. The spray unit includes a shaft 20, a disk 30, a disk shape-changing assembly 40, and a liquid applicator 50. The disk is configured to rotate about the shaft centered on the center of the disk. The liquid applicator is configured to apply liquid to a surface of the disk. The disk shape-changing assembly is configured to change the diameter of the disk, thereby changing the trajectory of liquid droplets leaving the spray unit.

[0037] The disk shape changing assembly can change the diameter of the disk 30 and thus affect the spray swath width. As a result, a proper application of active ingredient per plant per unit area of ​​land can be more easily provided. In example a) in FIG. 1, a spray unit with a narrower spray swath is illustrated, based on a narrower disk diameter by the disk shape changing assembly. In example b) in FIG. 1, a spray unit with a wider disk diameter by the disk shape changing assembly is illustrated, resulting in a wider spray swath (assuming that all other parameters, e.g. disk rotation speed, liquid flow, liquid itself, etc., are the same in examples a) and b).

[0038] In one example, the term "disc" refers to a flat disc, but also includes a cone-shaped disc.

[0039] In one example, the liquid applicator includes at least one supply pipe configured to transport liquid from a liquid reservoir to the disk and to supply the liquid onto the disk.

[0040] In one example, the liquid applicator includes at least one liquid tank and at least one supply pipe.

[0041] In one example, the term "liquid(s)" refers to liquid(s) that contain chemical-based and / or biological-based agriculturally active ingredients, such as, for example, herbicides, insecticides, fungicides, crop nutrients, biostimulants, plant growth regulators, and the like.

[0042] In one example, the phrase "the disk shape changing assembly is configured to change the trajectory of the liquid droplets" describes a change in the geographic location where the liquid droplets leave the spray unit toward the ground. Depending on the disk rotation speed, the liquid flow rate, and the liquid, changing the disk diameter by the disk shape changing assembly can also change the size and / or velocity of the liquid droplets leaving the spray unit toward the ground.

[0043] In one example, the disk shape changing assembly is configured to change the diameter of the disk during use of the spray unit to change the trajectory of liquid droplets leaving the spray unit, where use of the spray unit refers to spraying a target area with the liquid.

[0044] In one example, the disk shape changing assembly is configured to change the trajectory of liquid droplets leaving the spray unit by changing the diameter of the disk as the disk rotates about an axis centered on the center of the disk.

[0045] In one example, the disc shape changing assembly is configured to change the trajectory of liquid droplets leaving the spray unit by changing the diameter of the disc at the same time that the liquid applicator applies liquid to the surface of the disc.

[0046] In one example, an arrow near the shaft indicates a potential direction of rotation for the shaft and disk. The rotation can also be clockwise.

[0047] In one example, arrows on the plane of the disk represent directions for centrifugal force and atomization of the liquid.

[0048] In one example, an arrow next to the liquid droplet leaving the disk indicates the spray direction.

[0049] In one example, an arrow on the side of the disc shape changing assembly indicates the direction of disc diameter change by the spray direction assembly.

[0050] Fig. 2 shows a schematic configuration of an example of a spray unit 10 having a cone-shaped disk 30 in a side view. Except for the cone-shaped disk 30, the spray unit is similar to that shown in Fig. 1. The spray unit includes a shaft 20, a disk 30, a disk shape change assembly 40, and a liquid applicator 50. In this example, at least one actuator 60 configured to change the diameter of the disk shape change assembly is also shown. The arrows in Fig. 2 have the same meaning as explained in the context of Fig. 1.

[0051] According to one example, the disc shape changing assembly 40 includes at least one movable shape determining member configured to change the diameter of the disc 30 or the diameter of the second disc 31 (in this case the spray unit includes the second disc 31) by changing the position of at least a part of the shape determining member, and the disc shape changing assembly includes at least one actuator 60 configured to drive the at least one shape determining member.

[0052] In one example, at least one actuator refers to at least one mechanical device that converts energy into motion. The energy source may be, for example, electric current, hydraulic fluid pressure, pneumatic pressure, mechanical energy, thermal energy, or magnetic energy. For example, an electric motor assembly may be a type of actuator that converts electric current into rotational motion and may further convert the rotational motion into linear motion to perform actuation. Thus, an actuator may include a motor, gears, links, wheels, screws, pumps, pistons, switches, servos, or other components for converting a form of energy into motion.

[0053] In one example, the location of at least one actuator 60 is proximate to the shaft 20 , the disk 30 , and / or the disk shape-changing assembly 40 .

[0054] According to one example, the disk shape changing assembly includes at least one shape defining member selected from the group consisting of a blade 41 , an elastic film 42 and a slotted circular disk 43 .

[0055] In one example, a schematic configuration of an example of a disk shape-changing assembly including a blade is illustrated in FIGS.

[0056] In one example, a schematic configuration of an example disk shape-changing assembly including an elastic film is illustrated in FIGS.

[0057] In one example, a schematic configuration of an example disc shape-changing assembly including a slotted circular disc is shown in FIGS.

[0058] FIG. 3 shows a schematic configuration of an example of a spray unit 10 with a disk shape change assembly 40 on a second disk 31 in a side view. The spray unit includes an axle 20, a disk 30, a second disk 31 with a disk shape change assembly 40, a liquid applicator 50, and at least one actuator 60. The disk is configured to rotate about an axle centered on the center of the disk. The liquid applicator is configured to apply liquid to the surface of the disk. The disk shape change assembly is configured to change the diameter of the second disk to change the trajectory of liquid droplets leaving the spray unit. The arrows in FIG. 2 have the same meaning as those shown in FIG. 1.

[0059] In one example, the second disc 31 is adjacent to disc 30 and is located below disc 30 relative to the ground.

[0060] In one example, the second disc 31 is positioned as close as possible to the disc 30 (eg, within 1 millimeter or less) while still allowing the disc 30 to rotate about the shaft 20 .

[0061] In one example, the second disk 31 is disposed substantially symmetrically and parallel to disk 30 (preferably minimally spaced axially).

[0062] In one example, the second disc 31 has a similar diameter as the disc 30 .

[0063] FIG. 4 shows a schematic configuration of an example of a spray unit 10 having a disk 30 or a second disk 31 and a disk shape changing assembly 40 including a blade 41 in a bottom view. The disk shape changing assembly includes at least two blades 41, at least one blade pivot point 44, a blade drive link 61, and at least one inter-blade link 45, each of the at least two blades 41 being connected to the disk 30 or to the second disk 31 via at least one blade pivot point 44, at least one actuator 60 being configured to be connected to at least one of the two blades 41 via the blade drive link 61, and the at least two blades being connected by at least one inter-blade link 45. In example a) in FIG. 4, some blades 41 are shown in their respective initial (non-extended) positions. In example b) in FIG. 4, all blades move outward simultaneously by rotating about their respective blade pivot points in the direction shown by the curved arrows. Simultaneous movement of all blades is made possible by actuator action in cooperation with the blade drive links and inter-blade links. The increased diameter of the disk is represented by the double-ended arrow. For illustrative purposes, FIG. 4 only illustrates a few blades, a few blade pivot points, and a few inter-blade links. In operation, these components are distributed circumferentially across the disk.

[0064] FIG. 5 shows a schematic arrangement of an example of a spray unit 10 with a disk 30 or a second disk 31 and a disk shape changing assembly 40 including a blade 41 in a plan view. This example is similar to the one described in FIG. 4 (but from a different perspective). In example a) the blade is shown in a non-extended position, whereas in example b) the blade is shown in an extended position resulting in a larger diameter of the disk (as again represented by the double-ended arrows). FIG. 5 also shows the liquid atomization process (in black). For illustrative purposes, FIG. 5 shows only some blades. In operation, these components are distributed circumferentially over the entire disk.

[0065] In one example, the diameter change of the disk 30 by the disk shape change assembly occurs at a radial position from the center of the disk that is greater than the radial position at which liquid dispersal occurs on the rotating (spinning) disk.

[0066] Fig. 6 shows a schematic configuration of another example of the spray unit 10 having the disk 30 or the second disk 31 and the disk shape changing assembly 40 including the blade 41 in a bottom view. The disk shape changing assembly includes at least two blades 41 (each blade also includes an elliptical portion shown in dotted lines), at least one blade pivot point 44, a blade driving link 61, and at least one inter-blade link 45, each of the at least two blades 41 being connected to the disk 30 or to the second disk 31 via at least one blade pivot point 44 (circle shown in dotted lines), at least one actuator 60 being configured to be connected to at least one of the two blades 41 via the blade driving link 61, and at least two blades being connected by at least one inter-blade link 45. In the example a) in Fig. 6, some blades 41 are shown in their initial (non-extended) positions. In example b) in FIG. 6, all blades move outward simultaneously by radial movement along the blade pivot points in the direction shown by the straight arrows. The simultaneous movement of all blades is made possible by cooperation of the actuators and the blade drive links and inter-blade links. The widening of the disk diameter is represented by the double-ended arrows. For illustrative purposes, FIG. 4 only shows a few blades, a few blade pivot points and a few inter-blade links. In operation, these components are distributed circumferentially over the entire disk.

[0067] In one example, the at least one actuator is configured to control the actuation of the blade 41 .

[0068] In one example, the one or more blades 41 are configured to be driven by angle and / or position.

[0069] In one example, the blade or blades 41 have a planar shape.

[0070] FIG. 7 illustrates, in plan view, a schematic configuration of another example of a spray unit 10 with a disk 30 (or a second disk 31, not visible) and a disk shape-changing assembly 40 including a blade 41. This example is similar to the one described in FIG. 6 (but from a different perspective). In example a) the blade is illustrated in a non-extended position, whereas in example b) the blade is illustrated in an extended position resulting in a larger diameter of the disk (again as represented by the double-ended arrows). FIG. 7 also illustrates (in black) the liquid atomization process. For illustrative purposes, FIG. 7 illustrates only some blades. In operation, these components are expanded over the entire disk.

[0071] FIG. 8 shows a schematic configuration of an example of a spray unit 10 having a disk 30 or a second disk 31 and a disk shape-changing assembly 40 including an elastic film 42 in a bottom view. The disk shape-changing assembly includes a concentric elastic film 42 attached to the edge of the disk 30 or to the edge of the second disk 31, the disk shape-changing assembly further includes at least two extensible rods 70, at least one rod pivot point 46, a rod drive link 62, and at least one inter-rod link 47, each of the at least two extensible rods 70 being connected to the disk or to the second disk and also to the elastic film via at least one rod pivot point 46, the rods being configured to stretch and relax the elastic film equally in all radial directions, the at least one actuator 60 being configured to be connected to at least one of the two extensible rods via the rod drive link 62, the at least two rods being configured to be connected by at least one inter-rod link 47. In example a) in FIG. 8, the elastic films are shown in their default (unstretched) positions. In example b) in FIG. 8, the elastic film is stretched simultaneously in all radial directions. The simultaneous movement of the rods stretching the elastic film is enabled by actuator action in cooperation with the rod drive link and at least one inter-rod link. The widening of the disk diameter is represented by the double-ended arrow. For illustrative purposes, Figure 8 shows two extensible rods (positioned perpendicular to one another) and two optionally additional extensible rods (shown in dashed lines).

[0072] According to one example, the disk shape changing assembly includes at least four rods 70, at least one rod pivot point 46, a rod drive link 62, and at least one inter-rod link 47, each of the at least four rods 70 being connected to the disk 30 or to the second disk 31 and also to the elastic film via at least one rod pivot point 46, the rods being configured to stretch or relax the elastic film evenly in all radial directions, at least one actuator 60 being configured to be connected to at least one of the four extensible rods via the rod drive link 62, and the at least four rods being configured to be connected by at least one inter-rod link 47.

[0073] In one example, the disk shape changing assembly includes at least six rods 70, at least one rod pivot point 46, a rod drive link 62, and at least one inter-rod link 47, each of the at least six rods 70 being connected to the disk 30 or to the second disk 31 and also to the elastic film via at least one rod pivot point 46, the rods being configured to stretch or relax the elastic film equally in all radial directions, at least one actuator 60 being configured to be connected to at least one of the six extendable rods via the rod drive link 62, and the at least six rods being configured to be connected by at least one inter-rod link 47.

[0074] In one example, the disk shape-changing assembly 40 includes a plurality of extendable rods that interact in a manner similar to that described above in connection with at least six rods.

[0075] In another example, at least one actuator is configured to control actuation of the extensible rod, and thus, to control the extension of the elastic film.

[0076] In one example, the elastic film is a monolayer film, or a multi-component elastic film material, or a multi-layer film material, preferably of constant thickness.

[0077] In one example, the elastic film is substantially continuous in at least the cross direction.

[0078] In one example, the elastic film is a thermoplastic polymer composition.

[0079] In one example, the extendable rod includes multiple components configured to slide in and out of one another according to a telescopic principle.

[0080] According to one example, a plurality of rods (70) are arranged in a substantially radially symmetrical arrangement below the disc (30) or below the second disc (31).

[0081] According to one example, the second disc (31) is arranged axially spaced below disc (30).

[0082] According to one example, the second disc (31) is minimally spaced axially from the disc (30).

[0083] Figure 9 shows a schematic arrangement of an example of a spray unit 10 in plan view with a disk 30 or a second disk 31 (not visible in this view) and a disk shape-changing assembly 40 including an elastic film 42. This example is similar to the one described in Figure 8 (but from a different view). In example a) the elastic film is shown in a non-stretched position, whereas in example b) the elastic film is shown in a stretched position resulting in a larger diameter of the disk (again as represented by the double-headed arrows). Figure 9 also shows the liquid atomization process (in black). The extendable rods 70 are not visible because they are located below the disks (relative to the ground) and constitute the respective disk shape-changing assemblies.

[0084] 10 illustrates a schematic configuration of an example spray unit 10 having a disk shape-changing assembly 40 including at least one slotted circular disk 43 in side view. The spray unit includes a shaft 20, a disk 30, a disk shape-changing assembly 40, and a liquid applicator 50. The disk shape-changing assembly includes at least one slotted circular disk 43 configured to laterally surround the disk 30 to thereby expand a diameter of the disk, and at least one actuator 60 configured to control a position of the at least one slotted circular disk relative to the disk.

[0085] In one example, the actuator 60 includes a slotted circular disc drive link member 63 that connects the at least one actuator to the slotted circular disc either directly or by physically interacting with the slotted circular disc's connecting member 48 (the slotted circular disc 43 includes a connecting member 48).

[0086] According to one example, the disk shape changing assembly 40 includes at least two slotted circular disks 43, a second of the at least two slotted circular disks configured to laterally surround the first slotted circular disk, and at least one actuator 60 configured to control the position of the second slotted circular disk relative to the first slotted circular disk and / or relative to disk 30.

[0087] In one example, the shape-changing assembly 40 includes at least one slotted circular inter-disk link 49, and at least two slotted circular discs 43 are configured to be connected by the at least one slotted circular inter-disk link 49.

[0088] In one example, the disk shape-changing assembly 40 includes a plurality of slotted circular disks that interact in a manner similar to that described above in connection with the first slotted disk and the second slotted disk.

[0089] In another example, the at least one actuator is configured to control the actuation of at least one slotted circular disk.

[0090] In one example, at least one slotted circular disk is positioned above or below the disk (relative to the ground).

[0091] In one example, a number of slotted circular disks are positioned above and / or below the disk (relative to the ground).

[0092] In example a) in FIG. 10, the disk 30 is shown with a plurality of circular slotted disks adjacent to it above its surface. The plurality of circular slotted disks do not intervene in the liquid atomization process. In example b) in FIG. 10, the disk is laterally surrounded by a first circular slotted disk, which is laterally surrounded by a second circular slotted disk. The disk diameter is therefore wider compared to the disk diameter in the case shown in example a), and therefore the spray swath is also wider compared to the spray swath in the case shown in example a) (provided that all other relevant parameters remain the same).

[0093] In one example, an arrow near the shaft indicates a potential direction of rotation for the shaft and disk. The rotation can also be clockwise.

[0094] In one example, an arrow next to the liquid droplet leaving the spray unit indicates the spray direction.

[0095] FIG. 11 shows a schematic configuration of another example of a spray unit 10 with a disk shape-changing assembly including at least one slotted circular disk in a side view. This example is similar to that shown in FIG. 10, except that at least one circular disk is disposed below the disk (relative to the ground) and is driven toward the disk from below to laterally surround the disk and expand the diameter of the disk. In example a) in FIG. 11, the disk 30 is shown with multiple slotted circular disks 43 (as part of the disk shape-changing assembly 40) in close proximity to the disk below the disk surface. The multiple circular slotted disks do not participate in the liquid atomization process. In example b) in FIG. 11, the disk is laterally surrounded by a first slotted circular disk, which is laterally surrounded by a second slotted circular disk. The diameter of the disc is therefore wider compared to the diameter of the disc in the case shown in example a) and therefore the spray swath is also wider compared to the spray swath in the case shown in example a) (provided that all other relevant parameters remain the same).

[0096] In one example, an arrow near the shaft indicates a potential direction of rotation for the shaft and disk. The rotation can also be clockwise.

[0097] In one example, an arrow next to the liquid droplet leaving the spray unit indicates the spray direction.

[0098] Figure 12 shows schematic examples of a slotted circular disk 43 from different perspectives. Examples a) and b) in Figure 12 show a side view of the slotted circular disk, with an optional connecting member 48 located above or below the slotted circular disk. The optional connecting member 48 allows for a centralized drive control of at least one slotted circular disk relative to the disk. Example c) shows a similar slotted circular disk in plan view.

[0099] FIG. 13 illustrates a schematic configuration of another example of the spray unit 10, the second shaft 21, and the disk shape changing assembly 40 including a plurality of slotted circular disks 43 in a side view. The spray unit includes the shaft 20, the second shaft 21, the disk 30, the disk shape changing assembly 40, the liquid applicator 50, and at least one actuator 60. The disk shape changing assembly includes a plurality of slotted circular disks 43, the plurality of slotted circular disks configured to laterally surround the disk 30, thereby expanding the diameter of the disk, and the at least one actuator configured to control the position of the at least one slotted circular disk relative to the disk. The at least one actuator includes a slotted circular disk drive link member 63 that connects the slotted circular disk connecting member 48 to the at least one actuator. The plurality of slotted circular disks are connected by a slotted circular disk inter-disk link 49. The disk 30 rotates around the shaft 20. The plurality of slotted circular discs 43 is connected to the second shaft 21 via a connecting member 48, preferably at the centre of the connecting member. The arrows in Figure 13 have the same meaning as explained in Figure 11. The second shaft 21 can be either non-rotating or rotating.

[0100] According to one example, the disk shape changing assembly is configured to rotate about the shaft 20 or about the second shaft 21 .

[0101] According to one example, the disk shape-changing assembly is non-rotating.

[0102] According to one example, at least a portion of the surface of the disk shape change assembly against which the liquid droplets impinge as they leave the outer edge of the disk 30 has a low friction surface.

[0103] In one example, such a surface is hydrophobic.

[0104] The surface chemistry of such surfaces can be modified. In the case of smooth surfaces, the surface adhesion of the sprayed liquid (either as a film, ligaments or droplets) can be modified in this way. In the case of aqueous liquids, hydrophilic surfaces will be slippery and have more adhesion, whereas hydrophobic surfaces will be slippery and have less adhesion (and vice versa for oils). However, in the case of smooth surfaces, the range of accessible adhesion is not large (as seen by the narrow range of contact angles).

[0105] In one example, such surface of the disk shape-changing assembly is textured.

[0106] The surface may, for example, include a comb-like structure. As an example, 3D printing may be used to generate textured surface structures.

[0107] In one example, the size of the texture features is between 10 nm and 100 microns, preferably between 1 micron and 80 microns. In the case of micro-textured surfaces, the range of adhesion forces (and contact angles) is significantly increased. (Further details are provided in the article by Bico et al, Wetting of textured surfaces, Colloids and Surfaces A 206 (2002) 41-16).

[0108] In one example, such surfaces of the disk shape-changing assembly have a contact angle with water of greater than 110°, preferably greater than 120°.

[0109] In one example, such a surface is superhydrophobic, preferably having a contact angle with water of more than 150°, as known to those skilled in the art, the higher the angle the lower the adhesion force.

[0110] Recent advances in wetting of textured surfaces have resulted in surfaces that are non-wetting for a wide range of liquids (further details are provided in A Tuteja et al, Robust omniphobic surfaces, PNAS 105 (2008) 18200-18205; US Patent Publication Nos. 2019 / 0077968(A1); 2019 / 0039796(A1); 2015 / 0273518(A1); https: / / en.wikipedia.org / wiki / LiquiGlide). Such surfaces can also be used for at least a portion of the surface of the disk shape-changing assembly.

[0111] In one example, the spray unit may be used with boom sprayers, UAVs, unmanned ground vehicles (UGVs), robotic platforms, and backpack sprayers.

[0112] FIG. 14 illustrates a schematic example of a spray vehicle 100 having the spray unit 10 described with respect to any one of FIGS.

[0113] In one example, the spraying vehicle is a drone or UAV.

[0114] In one example, the spray vehicle is a land vehicle, such as an unmanned ground vehicle (UGV), a robotic platform, a tractor, or the like.

[0115] FIG. 15 illustrates a schematic example of a spray vehicle 100 having a spray unit 10 and at least one control member of the actuator 60 and thus the disk shape change assembly 40. The spray vehicle includes a liquid tank 110, at least one spray unit 10 as described herein, for example in relation to FIGS. 1-13, a number of sensors 120, and a processing unit 130. The liquid tank is configured to contain a liquid. The at least one spray unit is configured to spray the liquid. At least one sensor 121 of the number of sensors is configured to measure the rotational speed of the disk 30 around the shaft 20 centered on the center of the disk. At least one sensor 122 of the number of sensors is configured to measure the liquid flow rate from the liquid applicator 50 relative to the surface of the disk 30. The processing unit is configured to determine a liquid droplet size of the liquid droplets leaving the spray unit (alternatively, a liquid droplet size of the liquid droplets at the edge of the disk after atomization on the disk) including utilizing the measured rotational speed of the disk, the measured liquid flow rate from the liquid applicator to the disk surface, and physicochemical properties of the liquid. The processing unit is configured to control at least one actuator 60 of the spray unit, and determining at least one command for controlling the at least one actuator includes utilizing the determined liquid droplet size.

[0116] In one example, the at least one sensor 121 configured to measure the rotational speed of the disk about the shaft includes a tachometer (RPM gauge).

[0117] In one example, the at least one sensor 122 configured to measure the liquid flow rate from the liquid applicator relative to the surface of the disk is a rotameter.

[0118] In one example, the processing unit is configured to control at least one actuator, and determining at least one instruction for controlling the at least one actuator includes utilizing the determined liquid droplet size, a measured rotational speed for the disk, a measured liquid flow rate from the liquid applicator to the disk surface, and physicochemical properties of the liquid.

[0119] In one example, the processing unit is configured to determine a liquid droplet spectrum of liquid droplets leaving the spray unit (alternatively, a liquid droplet spectrum of liquid droplets at the edge of the disk after atomization on the disk), and the processing unit is configured to control at least one actuator, and determining at least one instruction for controlling the at least one actuator includes utilizing the determined liquid droplet spectrum.

[0120] The term "liquid droplet spectrum" refers to the size distribution of liquid droplets.

[0121] In one example, the spray vehicle further includes an input unit configured to receive data related to the physicochemical properties of the liquid. The input unit is configured to provide information related to the physicochemical properties of the liquid to the processing unit. As an example, the physicochemical properties of the liquid can be encoded on the packaging of the liquid, for example in a QR code that the input unit of the spray vehicle can scan.

[0122] According to one example, at least one sensor 123 of the plurality of sensors is configured to measure the speed of the spray vehicle relative to the ground, at least one sensor 124 of the plurality of sensors is configured to measure the air movement direction relative to the spray vehicle with respect to the longitudinal axis of the spray vehicle, and at least one sensor 125 of the plurality of sensors is configured to measure the air movement speed relative to the spray vehicle, and a processing unit is configured to determine the air movement direction with respect to the projection of the longitudinal axis on the ground and to determine the air movement speed with respect to the ground, the determination including utilizing the speed of the spray vehicle, the air movement direction with respect to the spray vehicle with respect to the longitudinal axis of the spray vehicle, and the air movement speed with respect to the spray vehicle, and the processing unit is configured to control the rotational speed of the disk, and / or the liquid flow rate from the liquid applicator to the disk surface, and / or at least one actuator, and the determination of at least one command for the control includes utilizing the determined air movement direction with respect to the projection of the longitudinal axis on the ground and the determined air movement speed with respect to the ground.

[0123] In one example, the at least one actuator is configured to control the disc shape-changing assembly 40, and preferably configured to drive the at least one shape defining member.

[0124] In one example, the at least one actuator is configured to control the actuation of the blade 41 .

[0125] In another example, at least one actuator is configured to control the actuation of the extensible rod 70 and thus the extension of the elastic film 42 .

[0126] In another example, the at least one actuator is configured to control the actuation of at least one slotted circular disc 43 .

[0127] According to one example, the spray vehicle further includes at least one sensor 126 in the plurality of sensors configured to provide data from which a height of the spray vehicle above the ground can be determined. The processing unit is configured to control the rotational speed of the disk, and / or the liquid flow rate from the liquid applicator to the disk surface, and / or the at least one actuator, and determining at least one command for the control includes utilizing the determined air movement direction with respect to the projection of the longitudinal axis on the ground, the determined air movement speed with respect to the ground, and the determined height of the spray vehicle above the ground.

[0128] In one example, controlling the rotational speed of the disks may also include controlling the rotational speed of the second disk 31 .

[0129] In one example, the at least one sensor 123 configured to measure the speed of the spray vehicle relative to the ground includes a GPS system.

[0130] In one example, the at least one sensor 123 configured to measure the speed of the spraying vehicle relative to the ground includes a laser reflectance-based system.

[0131] In one example, the at least one sensor 124 configured to measure the direction of air movement relative to the spraying vehicle includes a wind vane.

[0132] In one example, the at least one sensor 125 configured to measure air movement speed relative to the spraying vehicle includes an anemometer.

[0133] In one example, the at least one sensor 125 configured to measure air movement velocity relative to the spraying vehicle includes a Pitot tube.

[0134] In one example, the at least one sensor 124 and 125 configured to measure air movement direction, speed (and distance) relative to the spraying vehicle includes a LIDAR sensor, preferably a Doppler LIDAR sensor.

[0135] In one example, the sensor 126 used to determine height is a radar sensor.

[0136] In one example, the sensor 136 used to determine height is a laser time-of-flight sensor.

[0137] FIG. 16 illustrates a schematic example of a spraying vehicle 100 with a spraying unit 10 and a control member of the disk shape changing assembly 40 as a function of different liquid droplet sizes. In this example, the spraying vehicle is a UAV and includes at least one spraying unit arranged under a propeller unit of the UAV. The spraying unit includes a spray direction assembly 40 with a spray direction assembly configured to change the diameter of the disk 30. A number of sensors 120 (not shown) sense, among other things, the rotation of the disk and the liquid flow from the liquid applicator to the disk surface. A processing unit 130 determines the liquid droplet size of the liquid droplets leaving the spraying unit. The processing unit further uses the sensed and calculated information to instruct at least one actuator (not shown) to control the diameter of the disk via the disk shape changing assembly. In example a), the droplet size of the atomized liquid leaving the spraying unit is large (and the rotation speed of the disk is small), in which case the shape defining member of the disk shape changing assembly is driven to expand the diameter of the disk. In example b), the droplet size of the atomized liquid droplets leaving the spray unit is smaller (and the rotational speed of the disk is higher), in which case the shape defining member of the disk shape changing assembly is driven to its unextended position to generate a spray swath similar to example a). In examples a) and b), it is assumed that the liquid flow rate and liquid are the same.

[0138] It should be noted that the embodiments of the present invention are described with reference to different subject matters. In particular, some embodiments are described with reference to spray unit type claims, while other embodiments are described with reference to spray vehicle type claims. However, a person skilled in the art will infer from the above and following descriptions that, unless otherwise specified, any combination of features belonging to one type of subject matter, as well as any combination between features related to different subject matters, is considered to be disclosed by the present application. However, all features can be combined and can provide synergistic effects that exceed the mere sum of the features.

[0139] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the dependent claims.

[0140] In the claims, the term "comprising" does not exclude other elements or other steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be interpreted as limiting their scope.

Claims

1. A spray unit (10), comprising: - a shaft (20), a disk (30), - a disk shape changing assembly (40); a liquid applicator (50), the disk is configured to rotate about the shaft centered on a center of the disk; the liquid applicator is configured to apply liquid to a surface of the disc; The disk shape changing assembly is configured to change the diameter of the disk, thereby changing the trajectory of liquid droplets leaving the atomization unit (10).

2. The disk shape-changing assembly includes at least one movable shape defining member; the at least one movable shape-defining member is configured to vary the diameter of the disc (30) or the diameter of the second disc (31) by varying the position of at least a part of the shape-defining member, 2. The spray unit of claim 1, wherein the disk shape-changing assembly includes at least one actuator (60) configured to actuate the at least one shape-defining member.

3. 3. The spray unit according to claim 2, wherein the disc shape changing assembly comprises at least one shape defining member selected from the group consisting of a blade (41), an elastic film (42), and a slotted disc (43).

4. The disk shape changing assembly includes at least two blades (41); Each of the at least two blades is connected to the disk (30) or to a second disk (31) via at least one blade pivot point (44); the at least one actuator is configured to be coupled to at least one of the at least two blades via a blade drive link (61); A spray unit according to claim 3, wherein the at least two blades are configured to be connected by at least one inter-blade link (45).

5. The disk shape change assembly includes a concentric elastic film (42) attached to an edge of the disk (30) or to an edge of a second disk (31); The disk shape changing assembly further includes at least two extendable rods (70); Each of the at least two extensible rods is connected to the disk or to a second disk and to the elastic film via at least one rod pivot point (46); the rods are configured to stretch and relax the elastic film evenly in all radial directions; the at least one actuator (60) is configured to be coupled to at least one of the two extendable rods via a rod drive link (62); A spray unit according to claim 3, wherein the at least two rods are configured to be connected by at least one inter-rod link (47).

6. The disk shape changing assembly includes at least four rods (70); each of said at least four rods is connected to said disk (30) or to a second disk (31) and further to said elastic film via at least one rod pivot point (46); the rods are configured to stretch and relax the elastic film evenly in all radial directions; the at least one actuator (60) is configured to be coupled to at least one of the four extendable rods via a rod drive link (62); A spray unit according to claim 5, wherein the at least four rods are configured to be connected by at least one inter-rod link (47).

7. A spray unit according to claim 5 or 6, wherein the rods (70) are arranged in a substantially radially symmetrical arrangement below the disc (30) or below the second disc (31).

8. A spray unit according to any one of claims 2 to 7, wherein the second disc (31) is arranged axially spaced below the disc (30).

9. The disk shape change assembly includes at least one slotted circular disk (43); the at least one slotted circular disk is configured to laterally surround the disk (30) and thereby expand the diameter of the disk; 4. The spray unit of claim 3, wherein the at least one actuator (60) is configured to control the position of the at least one slotted circular disc relative to the disk.

10. The disk shape changing assembly includes at least two slotted circular disks (43); a second slotted circular disk of the at least two slotted circular disks configured to laterally surround the first slotted circular disk; 10. A spray unit according to claim 9, wherein the at least one actuator (60) is configured to control the position of the second slotted circular disc relative to the first slotted circular disc and / or relative to the disc (30).

11. A spray unit according to any one of the preceding claims, wherein the disk shape-changing assembly is configured to rotate about the shaft (20) or about a second shaft (21).

12. A spray unit according to any one of claims 1 to 10, wherein the disc shape-changing assembly is non-rotating.

13. A spray unit according to any one of claims 1 to 12, wherein at least a portion of the surface of the disc shape change assembly against which the liquid droplets impinge as they leave the outer edge of the disc (30) has a low friction surface.

14. A spraying vehicle (100) comprising at least one spraying unit (10) according to any one of the preceding claims.

15. A spray vehicle, a liquid tank (110), - at least one spray unit (10) according to any one of claims 2 to 13, a plurality of sensors (120); a processing unit (130), The liquid tank is configured to contain a liquid; The at least one spray unit is configured to spray a liquid; At least one sensor (121) in the plurality of sensors is configured to measure a rotational speed of the disk (30) about the shaft (20) centered on a center of the disk; At least one sensor (122) in the plurality of sensors is configured to measure a liquid flow rate from the liquid applicator (50) relative to a surface of the disk (30); the processing unit is configured to determine a liquid droplet size of the liquid droplets leaving the spray unit, including by utilizing the measured rotational speed of the disk, the measured liquid flow rate from the liquid applicator to the disk surface, and physico-chemical properties of the liquid; The processing unit is configured to control the at least one actuator (60) of the spray unit; The determining of at least one command for controlling the at least one actuator includes utilizing the determined liquid droplet size.

16. a liquid tank (110), - at least one spray unit (10) according to any one of claims 2 to 13, a plurality of sensors (120); a processing unit (130), The liquid tank is configured to contain a liquid; The at least one spray unit is configured to spray a liquid; At least one sensor (123) in the plurality of sensors is configured to measure a speed of the spray vehicle relative to a ground surface; At least one sensor (124) in the plurality of sensors is configured to measure a direction of air movement relative to the spraying vehicle with respect to a longitudinal axis of the spraying vehicle; At least one sensor (125) in the plurality of sensors is configured to measure air movement velocity relative to the spraying vehicle; the processing unit is configured to determine an air movement direction relative to a projection of the longitudinal axis onto a ground surface and configured to determine an air movement speed relative to the ground surface; The determining includes utilizing the speed of the spraying vehicle, the direction of air movement relative to the spraying vehicle with respect to the longitudinal axis of the spraying vehicle, and the speed of air movement relative to the spraying vehicle; the processing unit is configured to control the rotational speed of the disk, and / or the liquid flow rate from the liquid applicator to the disk surface, and / or the at least one actuator; The spray vehicle of claim 14, wherein determining at least one command for control includes utilizing the determined air movement direction relative to a projection of the longitudinal axis onto the ground and the determined air movement speed relative to the ground.

17. At least one sensor (126) in the plurality of sensors is configured to provide data from which a height of the spray vehicle above a ground surface can be determined; the processing unit is configured to control the rotational speed of the disk, and / or the liquid flow rate from the liquid applicator to the disk surface, and / or the at least one actuator; The spray vehicle of claim 16, wherein determining at least one command for control includes utilizing the determined air movement direction relative to a projection of the longitudinal axis on the ground, the determined air movement speed relative to the ground, and the determined height of the spray vehicle above the ground.

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