Mobile airbase for operating an agricultural unmanned aerial vehicle, method of operating mobile airbase and method of replenishing an unmanned aerial vehicle

Abstract

A mobile airbase (3) for operating an agricultural unmanned aerial vehicle, "UAV" (1), for distributing an agricultural product to an area over which the UAV travels comprises a frame (32), at least one ground support, in particular a wheel, rotatably connected to the frame (32), at least one landing platform (31), configured for receiving the UAV (1), and at least one product supply, configured for supplying at least one product to be distributed by the UAV (1). The product supply (351, 352) comprises a diluent tank (351), at least one product container (352, 352a, 352b, 352c, 352d), and a product nozzle (3513). The product nozzle (3513) comprises at least one diluent inlet (35132), connected to the at least one diluent tank (351), a product inlet (35133a, 35133b) connected to the product container (352, 352a, 352b, 352c, 352d) and a nozzle outlet (35134). The product inlet (35133a, 35133b) is configured to inject the product into a flow of the diluent.

Description

[0001] MOBILE AIRBASE FOR OPERATING AN AGRICULTURAL UNMANNED AERIAL VEHICLE, METHOD OF OPERATING MOBILE AIRBASE AND METHOD OF REPLENISHING AN UNMANNED AERIAL VEHICLE

[0002] Technical field

[0003] The present disclosure relates generally to the use of unmanned aerial vehicles (“UAVs”) in agriculture, and in particular to distribution of one or more products in liquid form to an area over which the UAV flies.

[0004] Background

[0005] In agriculture it is common to use added product or substance, such as fertilizer, herbicides or pesticide to improve the yield from the crops or to prevent weeds or pests. Other products include minerals, chalk or seeds. The product may be in granulated, powdered, or liquid form.

[0006] Different distribution techniques exist for product of the different forms. The product is commonly spread from agricultural implements which may be mounted on, or towed behind, a tractor or other type of self-propelled vehicle. In some areas, airborne spreading is practiced by airplanes or helicopter, however, such practices are costly, and in many areas, such practices are not permitted.

[0007] Moreover, airborne spreading is generally associated with a lack of precision, due to the height and speeds at which it is carried out.

[0008] A common problem for traditional spreading techniques is the inevitable tramlines needed. Tramlines decrease the arable field area and increase soil compaction locally. Also, tramlines tend to further erosion, in particular on sloping fields, where soil is led away by water flowing in the tramlines.

[0009] Moreover, ground-based spreading may be difficult when fields are wet, as machines tend to sink and get stuck.

[0010] Another common problem for the spreading techniques is the effect from wind, which may interfere with the desired throwing pattern from acentrifugal spreader, or with the mist created from a liquid spreading implement, in a negative way. Rain may also cause problems, limiting the ability for tractors or other ground-based vehicles to get traction in field.

[0011] Hence, there has arisen an interest in the use of UAVs or “drones” equipped with spreader units for spreading various products.

[0012] While one line of development in the field of agricultural UAVs is to use a large number of small UAVs, another line of development is to use fewer but larger UAVs. For example, a larger UAV for distribution of agricultural product may have a distribution width of about 10-15 m and a load capacity of about 100-1000 kg.

[0013] However, the use of UAVs in agriculture is still in its infancy and hence there is a need for improvements in their capabilities, operation and in their precision.

[0014]

[0015] It is an objective of the present disclosure to provide solutions which eliminate or alleviate at least some of the disadvantages mentioned above. A particular provide solutions that allow the use of larger UAVs for distribution of a product to an area.

[0016] The invention is defined by the appended independent claims.

[0017] Embodiments are set forth in the appended dependent claims, in the following description and in the attached drawings.

[0018] According to a first aspect, there is provided a mobile airbase for operating an agricultural unmanned aerial vehicle, “UAV” for distributing an agricultural product to an area over which the UAV travels, the mobile airbase comprising a frame, at least one ground support, in particular a wheel, rotatably connected to the frame, at least one landing platform, configured for receiving the UAV, and at least one product supply, configured for supplying at least one product to be distributed by the UAV. The product supply comprises a diluent tank, at least one product container, and a product nozzle. The product nozzle comprises at least one diluent inlet, connected to the at least one diluent tank, a product inlet, connected to the productcontainer and a nozzle outlet. The product inlet is configured to inject the product into a flow of the diluent.

[0019] An agricultural product is defined as a product that is to be distributed in the course of agriculture. In most cases, the product will be solid or liquid, but a gaseous product is not excluded. For example, the product may be one or more of seeds, fertilizer, pesticide, insecticide, fungicide, or the like.

[0020] The diluent tank(s) may be configured to hold an amount of a diluent, in particular water.

[0021] The product container (s) may be configured to hold a respective amount of a respective concentrated product, that is to be diluted by the diluent. The product container may be a container in which the product is delivered from its manufacturer or distributor, without the need for the operator to handle the concentrated product, in particular by pouring a liquid from one container to another. However, the principle may also be applied to a product container that has been refilled with concentrated product.

[0022] A product nozzle is a nozzle to be used for filling product to a product tank of the UAV. In particular, the nozzle provides the part which releasably engages a product inlet of a product tank that forms part of, or is carried by, the UAV.

[0023] The nozzle may be connected to a product tank inlet via a quickconnection.

[0024] By “quick-connection” may be meant that the product nozzle is insertable to, and removable from, a product inlet of a product tank without being locked or secured thereto.

[0025] By “quick-connection” may be meant a connection configured for easy insertion and removal of the nozzle relative to an inlet of a product tank, without requiring any tools.

[0026] By “quick-connection” may be meant that the product nozzle is releasable by movement relative to the product tank. The movement may be generally linear and only partly rotational, such as less than 360 degrees or less than 180 degrees.A quick-connection may comprise a tube device of the nozzle configured for inserting in a receiving hole of a product tank. Such tube device may act on a inlet valve to open a flow path to an inlet pipe of the product tank inlet.

[0027] A quick-connection may comprise gaskets or o-rings to seal a space between the nozzle and the inlet of the product tank.

[0028] A quick-connection generally does not include threads.

[0029] By injecting the concentrated product into the flow of diluent in the product nozzle, there is no need for any buffer tank for storing the diluted product, hence, the number of components that need cleaning is reduced.

[0030] The product nozzle may comprise an elongated part, which is displaceable along its longitudinal direction, and an actuator configured to control a position along a longitudinal direction of the elongated part.

[0031] The product nozzle may comprise at least one product inlet, connected to a product container.

[0032] The product supply may comprise a product pump and / or a product meter.

[0033] The mobile airbase may further comprise a product container rinsing system, comprising a diluent supply, and a spray device, connected to the diluent supply and configured for spraying an interior of the product container.

[0034] The diluent supply of the product container rinsing system may be connected to the diluent tank, optionally by a pump.

[0035] The diluent supply may comprise a diluent inlet, a diluent pump and a diluent meter.

[0036] The mobile airbase may further comprise a ground controller connected to at least one product supply and to the diluent supply, and configured to control the supply of the at least one product and the supply of the diluent so as to provide a respective predetermined ratio of at least one product to diluent at the nozzle outlet.

[0037] In the mobile airbase, a product takeup pipe may be sized and adapted to extend to a bottom of a product container.The mobile airbase, a product level meter is provided at a lowermost portion of the product takeup pipe.

[0038] The mobile airbase may further comprise a product container holder, which is configured for holding a product container which is formed essentially as a right prism, said product container holder being inclined in two orthogonal planes relative to a horizontal plane.

[0039] According to a second aspect, there is provided a system comprising a mobile airbase as described above and at least one unmanned aerial vehicle configured for distributing at least one liquid agricultural product to an area over which the UAV travels.

[0040] According to a third aspect, there is provided a method of replenishing at least one liquid diluted agricultural product of an agricultural unmanned aerial vehicle, “UAV”, for distributing a product to an area over which the UAV travels, the method comprising connecting a product nozzle to a product container of the UAV, feeding a diluent from a diluent tank to the product nozzle, and feeding at least one concentrated product from a product container to the product nozzle. The at least one concentrated product is injected into a flow of the diluent in the product nozzle, such that the diluted product is provided at a nozzle outlet.

[0041] At least two concentrated products may be fed from respective product containers to provide respective product ratios to the diluent at the nozzle outlet.

[0042] The flow of diluent and the at least one product may be disturbed as compared to a laminar flow in the product nozzle, so as to enhance mixing of the diluent and the at least one product.

[0043] According to a fourth aspect, there is provided a method of operating the mobile airbase as described above, the method comprising causing the UAV to land on the landing platform, connecting the product nozzle to a product tank of the UAV, and supplying, through the product nozzle, at least one product from the at least one product container diluted by the diluent from the diluent tank. Said supplying comprises, once a predetermined amount of diluted at least one product has been supplied to the product tank of the UAV,ceasing supply of the product to the product nozzle and subsequently ceasing supply of the diluent to the product nozzle, such that the product nozzle is flushed from product residues.

[0044] According to a fifth aspect, there is provided a method of cleaning a product container of agricultural product residues, in a system comprising a diluent container and the product container, comprising providing a rinse nozzle, which is inserted into the product container, the rinse nozzle comprising a spray device for spraying the diluent upwardly into the product container; using a first pump to supply pressurized diluent to the rinse nozzle, such that diluent is sprayed onto the entire interior of the product container; using a second pump to extract the product-laden diluent from a lowermost portion of the product container; supplying said product-laden diluent to a product tank of a product distribution device in the form of a UAV; and spreading the product-laden diluent to an area over which the UAV is travelling.

[0045] The product-laden diluent may be spread to an area where the product, even when diluted, may have a positive yet decreased effect on growing crops or plants. Such area may be pastureland or forest. Such area may be agricultural area with growing plants or crops, which may benefit from the effect of the product even when diluted more than to achieve optimal effect.

[0046] It may be advantageous to spread the product-laden diluent away from farms, residential areas or cities, to not risk contaminating the ground or water courses where people or animals are present.

[0047] The method may comprise flying the UAV to a uninhabited rural area to spread the product-laden diluent.

[0048] It may be advantageous to spread the product-laden diluent to an area where it does not cause environmental harm and where it may be beneficial to growing crops or plants.

[0049] The product-laden diluent may be injected into a diluent flow provided to the product tank.The product container may be formed as an essentially right prizm, and the second pump may be configured to extract the product-laden diluent from a corner of the right prizm which is positioned such that it constitutes a unique lowermost point of the product container.

[0050] The rinse nozzle may be integrated with a product takeup nozzle that is used for extracting the product from the product container.

[0051] The product distribution device may be an unmanned aerial vehicle and wherein the diluent container and the product container are provided on a mobile airbase having at least one landing platform for receiving the UAV.

[0052] The rinse nozzle may be connected to a product takeup pipe.

[0053] The rinse nozzle may extend along, preferably concentrically with, a portion of the product takeup pipe.

[0054] For example, the rinse nozzle may extend along the product takeup pipe over at least 1 / 3 of the length of the product takeup pipe, preferably at leat >2 or at least % of the length of the product takeup pipe.

[0055] The spray device may be situated at a lowermost portion of the product takeup pipe.

[0056] For example, the spray device may be situated immediately adjacent the lowerpost part of the product takeup pipe. For example, a product level sensor may be situated between the lowermost part of the product takeup pipe and the spray device.

[0057] In order to determine that all of the product (concentrated for normal use, or diluted, in the rinsing scenario) has been drawn from the product container, it is possible to detect bubbles occurring in the channel from the product takeup pipe.

[0058] For example, it may be detected that the amount of air bubbles exceeds a threshold value, which may indicate that the product container is empty.

[0059] Such detection may be provided optically and / or acoustically.

[0060] According to a sixth aspect, there is provided a device for extracting a liquid agricultural product from a product container, comprising a product takeup pipe having a length sufficient to extend through an opening at anupper portion of the product container and to reach a bottom of the product container; and a product inlet at one end of the product takeup pipe. A rinse nozzle, which is connected to the product takeup pipe, and which extends along, preferably concentrically with, a portion of the product takeup pipe.

[0061] A product container is contemplated to be a closable container, in the form of a hollow body having a shape which is cylindrical or right prizm and which has an opening with a cross section that is smaller, preferably much smaller, than a cross section of the hollow body.

[0062] A spray device may be situated at a lowermost portion of the product takeup pipe, the spray device being configured to provide a spray in a direction away from the product inlet.

[0063] The direction away from the product inlet may be a direction towards the upper portion of the product container.

[0064] According to a seventh aspect, there is provided a mobile airbase for operating an agricultural unmanned aerial vehicle, “UAV”, for distributing an agricultural product to an area over which the UAV travels, the mobile airbase comprising a frame, at least one ground support, in particular a wheel, rotatably connected to the frame, at least one landing platform, configured for receiving the UAV, at least one product supply, configured for supplying at least one product to be distributed by the UAV, an intermediate tank, and a quick transfer channel, configured for rapidly transferring product from the intermediate tank to a product tank of the UAV.

[0065] The product may be one or more products to be distributed by the UAV, in particular liquid products. The system may comprise one intermediate tank and optionally one quick transfer channel for each product to be transferred.

[0066] The mobile airbase may further comprise a pressurization system for pressurizing the intermediate tank to provide pressure-assisted transfer of the product from the intermediate tank to the product tank.

[0067] The pressure may in particular be a gas pressure, such as air pressure.The product supply may comprise a diluent tank, at least one product container, and a product nozzle, the product nozzle comprising at least one diluent inlet, connected to the at least one diluent tank, a product inlet connected to the product container and a nozzle outlet, wherein the product inlet is configured to inject the product into a flow of the diluent.

[0068] The product nozzle may be fixedly connected or connectable to the intermediate tank.

[0069] According to an eighth aspect, there is provided a method of operating a UAV and a mobile airbase, the mobile airbase comprising a frame, at least one ground support, in particular a wheel, rotatably connected to the frame, at least one landing platform, configured for receiving the UAV, and at least one product supply, configured for supplying at least one product to be distributed by the UAV. The method comprises pre-filling at least one intermediate tank with a product to be transferred from the product supply to the UAV, causing the UAV to land on the landing platform, connecting a quick transfer channel between the intermediate tank and a tank of the UAV, and transferring the product from the intermediate tank to the tank via the quick transfer channel.

[0070] The product may be one or more products to be distributed or fuel. The intermediate tank may be pressurized. Hence, the transfer speed may be increased.

[0071] The intermediate tank may be positioned at a greater vertical level than the tank of the UAV. This may also increase transfer speed.

[0072] According to a ninth aspect, there is provided a method of cleaning an intermediate tank of agricultural product residues, in a system comprising at least one product tank, at least one diluent tank, an intermediate tank and an UAV tank, the method comprising supplying diluent from the diluent tank to the intermediate tank, and transferring product-laden diluent from the intermediate tank to the UAV tank.

[0073] Said supplying diluent from the diluent tank to the intermediate tank may comprise spraying or showering an inside of the intermediate tank with the diluent.Said transferring product-laden diluent from the intermediate tank to the UAV tank may comprise spraying or showering an inside of the intermediate tank with the product-laden diluent.

[0074] Said supplying diluent from the diluent tank to the intermediate tank and transferring product-laden diluent from the intermediate tank to the UAV tank may be repeated with volumes smaller than a UAV tank volume, and in particular volumes which are a unit fraction of the UAV tank volume.

[0075] The method may further comprise spreading the product-laden diluent to an area over which the UAV is travelling.

[0076] Drawings

[0077] Figs 1a-1b schematically illustrate an UAV and a mobile airbase.

[0078] Figs 2a-2f schematically illustrate a liquid filling system of the mobile airbase.

[0079] Fig. 3 schematically illustrates the mobile airbase with supplemental functions.

[0080] Detailed description

[0081] Throughout this specification, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0082] The terms "a" and "an" are used herein to refer to one or to more than one (i.e. to at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element.

[0083] In the context of this specification, modifying terms, such as "about", “approximately” and “substantially” are understood to refer to a range of numbers that a person of skill in the art would consider equivalent to the recited value in the context of achieving the same function or result. Any value, range or term thus modified is to be understood as being disclosed also without the modifying term.Referring to fig. 1a, an unmanned aerial vehicle (“UAV”) 1, commonly known as a “drone”, is an aircraft that operates without a human pilot on board. UAVs can be controlled remotely by a human operator and / or autonomously by onboard computers.

[0084] While UAVs may come in many different designs and configurations, in the present disclosure, the UAV will, as a non-limiting example, be assumed to comprise the following systems.

[0085] An UAV 1 would typically comprise an airframe 11 , i.e. the structure of the UAV, which includes the body, wings (if any), and landing gear 113. It provides the necessary support and shape for the drone. In the illustrated example, the airframe comprises a central and generally horizontally extending web 111 and a pair of generally horizontally extending flanges 112, end portions of which provide comers of a rectangle at which rotors 122 are positioned.

[0086] An UAV 1 would typically also comprise a propulsion system 121, 122, which would include the motor(s)121, rotor(s) 122, and sometimes jet engines, which generate the thrust needed for the UAV 1 to fly.

[0087] The propulsion system may also comprise a transmission system (not shown), for transferring mechanical power from one or more motors 121 to one or more rotors 122.

[0088] An UAV 1 would typically also comprise a power source 13, such as a battery or fuel system that provides the energy required to power the UAV’s systems and propulsion.

[0089] An UAV 1 would typically also comprise a flight control system 14, which would include the onboard computer and sensors (such as gyroscopes and accelerometers) that help stabilize and control the UAV during flight.

[0090] An UAV 1 would typically also comprise a communication system 15, which allows the UAV to communicate with the ground control station (ground controller 40) or operator, enabling remote control and / or data transmission.

[0091] An UAV 1 would typically also comprise a navigation system 16, including Global Navigation Satellite System (GNSS) and / or other sensors that help the UAV 1 determine its position and navigate to its destination.The navigation system may also include gyro(s) and accelerometer(s) for inertial navigation, which may be used in case of limited availability of GNSS.

[0092] An UAV 1 would typically also comprise a payload 17, which, depending on the UAV’s purpose, can include cameras, sensors, delivery packages, or other equipment that the UAV is designed to carry.

[0093] An UAV 1 may comprise a local beacon detector 18, which may be used for connecting to and navigating by a local beacon 181.

[0094] An UAV 1 may also comprise one or more cameras 19 for capturing images that can be used for manual flight, for navigation and / or for inspection. In particular, it may be desirable to provide one or more cameras having night vision capability, e.g. by having capability to pick up light in the infra-red spectrum.

[0095] In particular, one or more cameras 19 may be positioned to provide a view of a spreader unit, such that the distribution operation can be monitored, either in real-time or later.

[0096] The UAV 1 may also have one or more sensors for collision avoidance, such as radar sensors, lidar sensors, ultrasound sensors, laser sensors or cameras.

[0097] The various systems controlling the flight, navigation, communication and operation of the UAV 1 may be provided as separate systems, or as a wholly or partially integrated system, collectively referred to as a “onboard controller” 14, 15, 16.

[0098] A special case may be that the payload 17 has its own control system, although such control system would need to communicate with the onboard controller 14, 15, 16 or with the ground controller 40, e.g. when a need to replenish product is detected.

[0099] An UAV 1 would typically also require a ground controller 40, which comprises the interface used by the operator to control the UAV, which can be a handheld controller, a computer, or a more complex setup for larger UAVs.Typically, all actuators and / or sensors onboard the UAV 1 may be connected to the onboard controller, to enable the onboard controller to make autonomous decisions and / or for communication to / from the ground controller 40.

[0100] In some embodiments, communication may be only between the UAV 1 and the airbase 3, with all control functions being provided at the airbase 3, e.g. through the ground controller 40. In such embodiments, on-site operator control and / or supervision would be necessary.

[0101] In some embodiments, additional communication may be to a central control and / or monitoring site, such as via a direct communication link or via a cloud-based system. In such embodiments, the airbase 3 may operate as a gateway, such that the UAV 1 communicates with the airbase 3 and the airbase 3 forwards communication to / from the UAV 1 from / to a remote control site. In such embodiments, an operator could control and / or monitor several airbase / UAV systems remotely and / or ambulatory.

[0102] In some embodiments, the airbase 3 and the UAV 1 may both communicate with a central control site, such as via a direct communication link or via a cloud-based system. This would also allow an operator to control and / or monitor several airbase / UAV systems remotely and / or ambulatory.

[0103] The communication may utilize cellular and / or satellite-based communication technology. Optionally wlan functionality may be used by the airbase 3, if available where the airbase 3 is stationed.

[0104] Data processing and / or storage may be provided at the airbase 3, in a remote server and / or control site and or by cloud-based computing / storage.

[0105] In the present context, it is contemplated that the UAV 1 would be sized and adapted for payloads 17 in excess of 100 kg, preferably in excess of 200 kg or in excess of 400 kg. Such UAV platforms are commercially available, e.g. in a quadcopter configuration with a generally H-shaped airframe and a petrol- or jet fuel-powered turbo shaft engine.

[0106] The payload may comprise a spreader device 171 for spreading a liquid or solid product to ground over which the UAV travels. The spreader device 171 may comprise one or more product tanks 170, a spreader unit1711 and a spreader unit support 1712, which extends such that the spreader unit 1711 is situated outside an area of downwash from the rotors 122. The spreader unit 1711 may comprise one or more spreader discs (not shown) for spreading a solid (powdery or granular) product, such as fertilizer, pesticide, herbicide, fungicide, seeds, ora combination thereof. Alternatively, the spreader unit 1711 may comprise a sprayer boom for spreading a liquid product, such as fertilizer, pesticide, herbicide, fungicide, or a combination thereof.The product tank 170 may be provided with a product level sensor. For example a weight sensor, a pressure sensor, an optical sensor, a radar sensor, a lidar sensor, a magnetic sensor or an ultrasonic sensor may be used to detect the level of solid product in the product tank 170.

[0107] Hence, the UAV 1 may detect a low product level in the product tank 170, which may trigger the UAV 1 to return to the airbase 3 for replenishment.

[0108] As illustrated, the spreader device 171 may extend outside the downwash area from the rotors 122, such that the spreader device also defines a forward working direction Dw of the UAV 1. Optionally, the spreader device 171 may also extend downwardly from the UAV, preferably below a landing gear 113. Hence, the spreader device 171 extends outwardly from the airframe 111, 112 towards a direction which is the working direction Dw.

[0109] Alternatively, the product level sensor may be dispensed with. Instead a product feed sensor may be provided in the spreader unit, e.g. in the form of a detector (typically optical or acoustic) for detecting flow of the product in the channel of the spreader unit 171.

[0110] Hence, the UAV 1 may detect that the product flow in the channel has ceased, which may trigger the UAV 1 to return to the airbase 3 for replenishment.

[0111] Referring to fig. 1b, there is illustrated a mobile airbase 3 with a UAV 1 received at a landing platform 31 of the mobile airbase 3.

[0112] The mobile airbase 3 comprises a landing platform 31, which is supported by a frame 32. The frame 32 may provide one or more floors, such as a lower floor 321 and an upper floor 322. In the illustrated example, thelanding platform 31 is provided nearer the upper floor 322 than the lower floor 321.

[0113] The frame 32 may comprise one or more support legs (not shown), which may be deployed for stabilizing the airbase 3. Optionally, such support legs may be used to provide a predetermined orientation of the airbase 3, e.g. such that the landing platform 31 is oriented horizontally.

[0114] One or more grounding rods (not shown) may be provided on the frame 32, configured for providing grounding of the airbase 3. Such grounding rod may be electrically coupled with the frame 32 and configured to penetrate ground on which the airbase 3 is positioned.

[0115] A grounding rod may be integrated with one or more of the support legs, e.g. such that the grounding rod is made to penetrate ground when the support leg is lowered into contact with the ground.

[0116] In the illustrated example, the landing platform 31 is provided at a vertical level between the lower floor 321 and the upper floor 322. In particular, the landing platform may be situated at a vertical distance from the lower floor 321 which is about 20-80 % of a vertical distance between the lower floor 321 and the upper floor 322, preferably about 30-70 % or about 40-60 %.

[0117] Such a positioning of the landing platform 31 , or landing platforms if several, provides for decreased transport height of the airbase when the UAV(s) 1 are on the airbase 3. The positioning also provides for decreased build height in the event a solid replenishment system, such as the one in figs 5a-5b is to be provided.

[0118] Alternatively, the landing platform 31 may be provided on the upper floor 322, and flush with the upper floor 322.

[0119] The landing platform 31 may be provided with one or more weight sensors (not shown), configured for detecting a weight of the UAV 1.

[0120] The weight sensor(s) may be used to determine the level of fuel and / or product in the tank of the UAV 1 , instead of, or in addition to, any fuel level meter and / or product level meter provided in the UAV 1.Further, in the illustrated example, a tow bar 33 is provided, such that the airbase can be towed by a vehicle, such as a traction vehicle.

[0121] In the illustrated example, the airbase 3 is configured for operation with a farm tractor. However, the airbase may alternatively be configured for operation with a semi-trailer or a swap body type lorry or trailer.

[0122] It is conceivable that the airbase 3 may be provided on vehicle platform, either integrated with a heavy vehicle chassis or as a heavy vehicle trailer. It is also conceivable that the airbase may be provided as an autonomously drivable platform.

[0123] A ladder 34 may be provided to enable operator access to the upper floor 322. A handrail 37 may be provided at any floor where it may be required or desired. The handrail 37 may be foldable, so as to reduce height of the airbase 3 for transport.

[0124] A gate 371 may be provided at the upper floor 322 to prevent an operator from falling down the ladder, and / or to prevent an operator from entering the second floor 322 when an UAV 1 is on or near the landing platform 31. A position of the gate 371 may be detectable by the ground controller 40, such that the ground controller 40 may allow or deny a UAV 1 to land when the gate is in an open or unlocked position.

[0125] A locking state and / or position of the gate 371 may also be controllable by the ground controller 40, so as to selectively prevent access to the upper floor 322 when an UAV 1 is near or at the landing platform 31.

[0126] Optionally, the handrail 37 and the gate 371 , if any, may be configured also to prevent unauthorized access to all or parts of the airbase 3 and in particular to any upper floor 322.

[0127] At such protected parts of the airbase 3, there may be provided one or more cameras and / or biosensor(s) (motion detectors, etc.), configured to detect unauthorized access. Upon such detection, the ground controller 40 may be configured to indicate unauthorized access, to alert an operator and / or to prevent one or more UAVs 1 from landing at the airbase 3.

[0128] One or more antennas 41 , e.g. for GNSS and / or communication may be integrated with the handrail 37, so as to be foldable with the handrail 37.The mobile airbase 3 may be supported by ground supports 36, in particular wheels or tracks.

[0129] In the illustrated example, the lower floor 321 is configured to house diluent (such as water) in diluent containers 351 , product in product containers 352 and fuel in fuel containers 353.

[0130] The containers, and in particular the product containers, may be positioned on one or more slidable shelves 3211. Such shelves may be slidable in a horizontal direction, in particular laterally or rearwardly relative to the direction of travel for the airbase 3, such that they can be more easily accessed by an operator.

[0131] Side panels 3231 , 3232, 3233, 3234 may be provided to enclose the lower floor 321 in order to restrict access and to protect items stored on the lower floor from theft, dust, debris, rain or sun.

[0132] At least some of the side panels may be openable to provide access to the interior of the airbase 3.

[0133] Alternatively, or additionally, the airbase may comprise a device for swapping and / or recharging batteries for powering the UAV 1.

[0134] The ground controller 40 may be provided on the mobile airbase 3. The ground controller may comprise one or more control units, which control all or some of the functions of the airbase and / or the UAV 1. In some embodiments, the ground controller 40 may be embodied as a single processing device, while in other embodiments, the controller may consist of two or more controllers which control different functions, optionally with coordination therebetween.

[0135] A navigation beacon 181 for providing a local navigation signal to the UAV 1 may also be provided on the mobile airbase 3.

[0136] The airbase 3 may also comprise a power generation system (not shown), which may operate with a fuel-driven generator, a generator that is connectable to a power outlet of the traction vehicle and / or solar panels.

[0137] Alternatively, or additionally, the power generation system may comprise batteries. The power generation system may be used to power the functionsof the airbase and optionally to charge batteries of the UAV 1.Fig. 2a schematically illustrates a liquid replenishing system for the UAV 1.

[0138] The liquid replenishing system may comprise a fuel replenishing system and / or a liquid product replenishing system.

[0139] A fuel replenishing system may comprise a fuel container 353, a fuel pump 3531 and a fuel nozzle 3532, configured to connect to a fuel tank 13 of the UAV 1.

[0140] The fuel nozzle 3532 may be provided as an elongate member which may be fixed or retractable by means of an actuator controlled by the ground controller 40, or by a separate fuel controller (not shown).

[0141] The fuel nozzle 3532 may also be provided with one or more valves for regulating flows and / or with one or more sensors for detecting e.g. fuel flow, for detecting connection to the fuel tank 13 and / or for detecting fuel level in the fuel tank 13.

[0142] Such sensors may also be connected to the ground controller 40.

[0143] A liquid product replenishing system may comprise one or more diluent containers 351 and one or more product containers 352, 352a, 352b, 352c, 352d.

[0144] A diluent pump 3511 may be provide for the diluent container(s) 351. A diluent meter (not shown) may be provided for metering an amount of diluent delivered to a product nozzle 3513.

[0145] A product pump 3521a, 3521b, 3521c, 3521 d may be provided for each of the product containers 352, 352a, 352b, 352c, 352d.

[0146] Each product pump 3521a, 3521b, 3521c, 3521 d may be provided in order to meet a predetermined capacity requirement.

[0147] For example, one or more of the product pumps 3521a, 3521 b, 3521c, 3521 d may be provided as a centrifugal pump, in which a respective volume meter may be needed.

[0148] Additionally, or alternatively, one or more of the product pumps 3521a, 3521b, 3521c, 3521 d may be provided as a peristaltic pump, such that no additional volume meter may be needed.A respective product meter (not shown) may be provided for metering an amount of each individual product delivered to the product nozzle 3513.

[0149] One or more filters (not shown) may be provided in the channels connecting, in particular, the fuel tank 353 to the fuel nozzle 3532; the diluent container 351 to the product nozzle 3513 and / or the product containers 352a, 352b, 352c, 352d to the product nozzle 3513. Such filters may be configured for separating solid particles from the liquid.

[0150] Hence, the controller 40 may control the product pumps 3521a, 3521b, 3521c, 3521 d based on the flow of the diluent.

[0151] The diluent pump 3511 may be connected to the product nozzle 3513, configured for connecting to a product tank 170 of the UAV 1. In particular, the product nozzle 3513 may be configured to releasably connect to the product tank 170.

[0152] The product nozzle 3513 may be provided as an elongate member which may be fixed or retractable by means of an actuator 3514 controlled by the ground controller 40, or by a separate fuel controller (not shown).

[0153] A high pressure pump 3512 may be provided for feeding diluent from the diluent container to the product container(s) 352, 352a, 352b, 352c, 352d for rinsing the product containers(s) 352, 352a, 352b, 352c, 352d.

[0154] Onboard the UAV 1 , the product tank 170 may comprise a product tank filling inlet 172. An outlet of the product tank 170 may be connected to a product spreader unit 1711 via one or more product spreader pumps 1713 Fig. 2b schematically illustrates a magnified view of the product nozzle 3513 of fig. 2a.

[0155] A diluent inlet 35132 of the elongate body 35131 may be connected to the diluent container 351 via the diluent pump 3511.

[0156] A nozzle outlet 35134 is provided at a distal end of the elongate body 35131.

[0157] One or more product inlets 35133a, 35133b are provided between the diluent inlet 35132 and the nozzle outlet 35134 and configured to inject the product into the flow of diluent, such that the product is diluted by the diluent.In some embodiments, a mixer 35135 may be provided between the product inlets and the nozzle outlet 35134.

[0158] A mixer 35135 may be provided as a set of fixed baffles, vanes or helical guides, or as one or more movable impeller, that causes turbulence and optionally shearing of the flow of diluent and product so as to improve mixing.

[0159] The actuator 3514 may be a linear actuator which may be configured to extend and retract the product nozzle 3513 to / from engagement with the product tank 170 of the UAV 1.

[0160] Fig. 2c schematically illustrates a more detailed view of a product nozzle 3513.

[0161] As is illustrated in fig. 2c, the product inlets 35133a, 35133b may be designed with a respective product inlet 351331 body that extends into the channel defined by the elongate body 35131 , with at least one orifice 351332 through which the product may be released into the channel.

[0162] In some embodiments, one or more of the product inlets 35133a, 35133b may have two or more such orifices 351332.

[0163] The orifices 351332 may be distributed over the product inlet body 351331.

[0164] The product inlet body 351331 may be designed in various ways. As a non-limiting example, a product inlet body 351331 may be designed as an elongate and generally circular cylindrical member. In other embodiments, the product inlet body 351331 may be designed as a generally curved member or as a member having also an elongate cross section, such as oval or drop shaped.

[0165] In yet further embodiments, the product inlet body 351331 or part thereof may be designed to provide a venturi effect.

[0166] Also in fig. 2c, there is provided a more detailed view of the mixer 35135. In the illustrated example, the mixer 35135 comprises one or more mixer mounts 351351 , 351352 and one or more mixer vanes 351353, 351354, which may be affixed to the mounts and configured to createturbulence and / or shearing of the diluted product passing towards the nozzle outlet 35134.

[0167] Fig. 2d schematically illustrates a magnified view of one of the product containers 352 of fig. 2a. The product container 352 is a product container arranged on the mobile airbase 3 and intended to hold an amount of concentrated product that is to be diluted by the diluent.

[0168] The product container 352 may be a product package or canister, which may be in a standardized format that is delivered by the product supplier.

[0169] In the illustrated example, the product container 352 is provided as a container having a generally right prism shape with rounded corners.

[0170] Holders for product containers may be provided as cages or receptacles that are oriented such that the product container(s) 352 are held at an angle A to a horizontal plane, preferably such that one of the comers of the product container forms a lowermost point of the product container 352. To this end, the holder may provide an angle in each of two mutually orthogonal planes, which are both perpendicular to the horizontal plane.

[0171] Alternatively, the product container may be generally cylindrical, in which case it needs only be angled in one vertical plane to provide a lowermost point at which the product is most favorably picked up.

[0172] A product takeup pipe 3526 is provided having a length sufficient to reach a bottom of the product container 352 and in particular to reach the corner forming the lowermost point of the product container 352.

[0173] At a lowermost portion of the product takeup pipe 3526, there may be provided a product level detector 3522, which may be configured to detect a low level of the product. Alternatively, a product level detector may be provided along the entire takeup pipe 3526, such that a product level can be indicated at any time.

[0174] In some embodiments, it is possible to provide a rinse nozzle 3523 and a product takeup pipe 3526 that are formed as separate parts, which may be introduced into the product container 352 exclusively or simultaneously.Moreover, a product level detector 3522 may be provided as a separate part, which may be inserted into the product container independently of the rinse nozzle 3523 and / or the product takeup pipe 3526. Alternatively, a product level detector 3522 may be arranged on each of the rinse nozzle 3523 and the product takeup pipe 3526, such that the level in the container may be detected also when only a rinse nozzle 3523 or only a product takeup pipe 3526 is introduced.

[0175] The product takeup pipe 3526 may be connected to the product pump 3521a, 3521b, 3521c, 3521 d.

[0176] Optionally one or more controllable valves 35211 , one or more nonreturn valves and / or one or more product meters may be provided between the product takeup pipe 3526 and the product inlet 35133a, 35133b.

[0177] A rinse nozzle 3523 may be connected, in the sense that it is mounted to the product takeup pipe 3526, or formed in one piece therewith. The rinse nozzle 3523 may be connected to the diluent tank 351 via the high pressure pump 3512. A spray device 3524 may be provided on the rinse nozzle 3523 and directed upwardly for spraying an interior of the product container 352 in order to remove product residues from the product container 352.

[0178] Optionally one or more controllable valves 35121 , one or more nonreturn valves may be provided between the pump 3512 and the rinse nozzle 3523.

[0179] Hence, the product takeup pipe 3526 and the associated product pump 3521a, 3521b, 3521c, 3521 d may be used in a cleaning operation, whereby the inside of the product container 352 is sprayed with diluent and the resulting product-laden diluent is extracted by the product pump 3521a, 3521b, 3521c, 3521 d and injected into the product nozzle 3513. Such injection may, but need not, take place while diluent is fed to the product nozzle 3513, such that the (possibly diluted) product-laden diluent is fed to the product tank 170 of the UAV 1 and then optionally distributed by the UAV 1.

[0180] Fig. 2e schematically illustrates a magnified view of the product filling inlet of the product tank 170 of the UAV 1 of fig. 2a.The product tank 170 may be configured to hold diluted product, as provided from the product filling system via the product nozzle 3513.

[0181] The product inlet 172 may comprise an inlet funnel 1721 for facilitating engagement with the product nozzle 3513. Optionally, a cap 1722 may be provided.

[0182] A cap 1722 may be provided as a slidable or pivotable member.

[0183] Yet optionally, an inlet valve 174 may be provided that is configured to be opened by the nozzle 3513 and to otherwise close the product inlet 172 to prevent contamination and / or leakage from the product tank 170.

[0184] The product inlet 172 may connect to an inlet pipe 1723 which extends downwardly towards a bottom of the product tank 170.

[0185] Fig. 2f schematically illustrates a lower portion of the product tank 170. The inlet pipe 1723 may extend almost to the bottom of the product tank 170 and may end at an inlet nozzle 17231 which may be slightly curved towards a direction parallel with a bottom of the product tank 170.

[0186] The inlet pipe 1723 may be provided with a non-return valve, configured to prevent the product from moving upwardly through the inlet pipe 1723.

[0187] A product tank outlet 1701 is provided for extraction of product from the product tank 170. The product tank outlet may thus be connected to the one or more product spreader pumps 1713 which supply the product spreader unit 1711.

[0188] The product spreader pumps 1713 may be individually controllable, such that the spreading rate may be controlled.

[0189] To this end, for example, each of the product spreader pumps 1713 may feed one or a group of spreader nozzles 17111.

[0190] Referring to fig. 3, it may be desirable to provide for faster transfer of product or fuel from the mobile airbase to the UAV 1.

[0191] To this end, it is possible to provide an intermediate tank 360 on the mobile airbase 3, which, in the case of product is connected to a product tank 351 and / or a diluent tank 352. A quick transfer channel 363 in the form of apipe or hose may be provided for connecting the intermediate tank 360 to the product tank 170 of the UAV 1.

[0192] In the case of fuel, an intermediate tank would be connected to the fuel tank on the mobile airbase, and on the UAV 1.

[0193] The intermediate tank 360 may be positioned at a higher vertical level than a product tank of the UAV 1 , when received on the mobile airbase 3, such that the product can be transferred by means of gravity.

[0194] A pressurization system 362 may be provided for pressurizing the intermediate tank 360, such that the transfer time can be further reduced, or such that the intermediate tank 360 may be positioned at a lower vertical level than the UAV 1.

[0195] The pressurization system 362 may comprise a compressor and optionally a pressure tank for providing a gas pressure to drive the product or fuel from the intermediate tank 360 through the quick transfer channel 363 to the product tank 170, or from fuel tank to fuel tank, as the case may be.

[0196] Valves, in particular non-return valves and control valves, may be provided as needed.

[0197] When the UAV 1 approaches the mobile airbase 3 for replenishment, the intermediate tank(s) 360 may be prefilled with diluted product and / or fuel.

[0198] When the UAV 1 lands on the mobile airbase 3, quick transfer channel connection(s) is / are established and the product / fuel is rapidly transferred to the product tank 170, or fuel tank, as the case may be, on the UAV 1.

[0199] The mixing of the product and the diluent may take place upon filling the intermediate tank 360.

[0200] Cleaning of the intermediate tank 360 may be provided in the same manner as the cleaning of the product tank 170 of the UAV 1.

[0201] That is, a cleaning liquid, such as water, may be injected into the intermediate tank 360, preferably by spraying so as to catch any product clinging to the interior walls of the intermediate tank.

[0202] The product-laden cleaning liquid in the intermediate tank may then be transferred to the product tank, optionally also using a spraying device.It is possible to use a smaller amount of cleaning liquid in the intermediate tank 360, but to repeat the cleaning cycle once or more, with the cleaning liquid from one or more cycles of cleaning the intermediate tank 360 being collected in the product tank 170 to be distributed as disclosed above. To this end, the volume of diluent introduced into the intermediate tank may be an approximate unit fraction of the volume of the product tank 170, such as about for two cycles, about 1 / 3 for three cycles, etc.

Claims

26CLAIMS1. A mobile airbase (3) for operating an agricultural unmanned aerial vehicle, “UAV” (1), for distributing an agricultural product to an area over which the UAV travels, the mobile airbase (3) comprising:a frame (32),at least one ground support, in particular a wheel, rotatably connected to the frame (32),at least one landing platform (31), configured for receiving the UAV (1), andat least one product supply, configured for supplying at least one product to be distributed by the UAV (1),wherein the product supply (351, 352), comprises:a diluent tank (351),at least one product container (352, 352a, 352b, 352c, 352d), and a product nozzle (3513),the product nozzle (3513) comprising at least one diluent inlet (35132), connected to the at least one diluent tank (351), a product inlet (35133a, 35133b) connected to the product container (352, 352a, 352b, 352c, 352d) and a nozzle outlet (35134),wherein the product inlet (35133a, 35133b) is configured to inject the product into a flow of the diluent.

2. The mobile airbase (3) as claimed in claim 1, wherein the product nozzle (3513) comprises an elongated part, which is displaceable along its longitudinal direction, and an actuator (3514) configured to control a position along a longitudinal direction of the elongated part.

3. The mobile airbase (3) as claimed in claim 1 or 2, wherein the product nozzle (3513) comprises at least one product inlet (35133a, 35133b), connected to a product container (352, 352a, 352b, 352c, 352d).

4. The mobile airbase (3) as claimed in claim 3, wherein the product supply (351, 352) comprises a product pump (3521a, 3521b, 3521c, 3521 d) and / or a product meter.

5. The mobile airbase (3) as claimed in any one of the preceding claims, further comprising a product container rinsing system, comprising: a diluent supply (351),a spray device (3524), connected to the diluent supply (351) and configured for spraying an interior of the product container (352, 352a, 352b, 352c, 352d).

6. The mobile airbase (3) as claimed in claim 5, wherein the diluent supply of the product container rinsing system is connected to the diluent tank (351), optionally by a pump (35121).

7. The mobile airbase (3) as claimed in any one of the preceding claims, wherein the diluent supply (351) comprises a diluent inlet, a diluent pump (3511 ) and a diluent meter (3512).

8. The mobile airbase (3) as claimed in any one of the preceding claims, further comprising a controller (40) connected to at least one product supply (352) and to the diluent supply (351), and configured to control the supply of the at least one product and the supply of the diluent so as to provide a respective predetermined ratio of at least one product to diluent at the nozzle outlet (35134).

9. The mobile airbase (3) as claimed in any one of the preceding claims, wherein a product takeup pipe (3526) is sized and adapted to extend to a bottom of a product container (352, 352a, 352b, 352c, 352d).

10. The mobile airbase (3) as claimed in any one of the preceding claims, wherein a product level meter is provided at a lowermost portion of the product takeup pipe (3526).

11. The mobile airbase (3) as claimed in any one of the preceding claims, further comprising a product container holder, which is configured for holding a product container (352, 352a, 352b, 352c, 352d) which is formed essentially as a right prism, said product container holder being inclined in two orthogonal planes relative to a horizontal plane.

12. A system comprising a mobile airbase (3) as claimed in any one of claims 1-11 and at least one unmanned aerial vehicle configured for distributing at least one liquid agricultural product to an area over which the UAV (1) travels.

13. A method of replenishing at least one liquid diluted agricultural product of an agricultural unmanned aerial vehicle, “UAV” (1), for distributing a product to an area over which the UAV (1 ) travels, the method comprising:connecting a product nozzle (3513) to a product tank of the UAV (1 ), feeding a diluent from a diluent tank to the product nozzle (3513), and feeding at least one concentrated product from a product container (352, 352a, 352b, 352c, 352d) to the product nozzle (3513),whereby the at least one concentrated product is injected into a flow of the diluent in the product nozzle (3513), such that the diluted product is provided at a nozzle outlet (35134).

14. The method as claimed in claim 13, wherein at least two concentrated products are fed from respective product containers (352, 352a, 352b, 352c, 352d) to provide respective product ratios to the diluent at the nozzle outlet (35134).2915. The method as claimed in claim 13 or 14, wherein the flow of diluent and the at least one product is disturbed as compared to a laminar flow in the product nozzle (3513), so as to enhance mixing of the diluent and the at least one product.

16. A method of operating the mobile airbase (3) as claimed in any one of claims 1-11, the method comprising:causing the UAV (1) to land on the landing platform (31), connecting the product nozzle (3513) to a product tank of the UAV (1 ), andsupplying, through the product nozzle (3513), at least one product from the at least one product container (352, 352a, 352b, 352c, 352d) diluted by the diluent from the diluent tank (351 ),wherein said supplying comprises:once a predetermined amount of diluted at least one product has been supplied to the product tank of the UAV (1 ), ceasing supply of the product to the product nozzle (3513) and subsequently ceasing supply of the diluent to the product nozzle (3513), such that the product nozzle (3513) is flushed from product residues.

17. A method of cleaning a product container of agricultural product residues, in a system comprising a diluent container and the product container (352, 352a, 352b, 352c, 352d), comprising:providing a rinse nozzle (3523), which is inserted into the product container (352, 352a, 352b, 352c, 352d), the rinse nozzle (3513) comprising a spray device for spraying the diluent upwardly into the product container (352, 352a, 352b, 352c, 352d);using a first pump (3511 ) to supply pressurized diluent to the rinse nozzle (3523), such that diluent is sprayed onto the entire interior of the product container (352, 352a, 352b, 352c, 352d);30using a second pump (3521a, 3521b, 3521c, 3521 d) to extract the product-laden diluent from a lowermost portion of the product container (352, 352a, 352b, 352c, 352d);supplying said product-laden diluent to a product tank (170) of a product distribution device in the form of a UAV (1); andspreading the product-laden diluent to an area over which the UAV (1 ) is travelling.

18. The method as claimed in claim 17, wherein the product-laden diluent is injected into a diluent flow provided to the product tank (170).

19. The method as claimed in claim 17 or 18, wherein the product container (352, 352a, 352b, 352c, 352d) is formed as an essentially right prizm, and wherein the second pump (3521a, 3521b, 3521c, 3521 d) is configured to extract the product-laden diluent from a corner of the right prizm which is positioned such that it constitutes a unique lowermost point of the product container (352, 352a, 352b, 352c, 352d).

20. The method as claimed in any one of claims 17-19, wherein the rinse nozzle (3523) integrated with a product takeup nozzle (3526) that is used for extracting the product from the product container (352, 352a, 352b, 352c, 352d).

21. The method as claimed in any one of claims 17-20, wherein the product distribution device is an unmanned aerial vehicle and wherein the diluent container and the product container (352, 352a, 352b, 352c, 352d) are provided on a mobile airbase (3) having at least one landing platform (31) for receiving the UAV (1).

22. The method as claimed in any one of claims 17-21, wherein the rinse nozzle is connected to a product takeup pipe (3526).3123. The method as claimed in claim 22, wherein the rinse nozzle (3523) extends along, preferably concentrically with, a portion of the product takeup pipe (3526).

24. The method as claimed in claim 22 or 23, wherein the spray device (3524) is situated at a lowermost portion of the product takeup pipe (3526).

25. A device for extracting a liquid agricultural product from a product container (352, 352a, 352b, 352c, 352d), comprising:a product takeup pipe (3526) having a length sufficient to extend through an opening at an upper portion of the product container (352, 352a, 352b, 352c, 352d) and to reach a bottom of the product container (352, 352a, 352b, 352c, 352d); anda product inlet at one end of the product takeup pipe (3526), characterized bya rinse nozzle (3523), which is connected to the product takeup pipe (3526), and which extends along, preferably concentrically with, a portion of the product takeup pipe (3526).

26. The device as claimed in claim 25, wherein a spray device (3524) is situated at a lowermost portion of the product takeup pipe (3526), the spray device (3524) being configured to provide a spray in a direction away from the product inlet.

27. A mobile airbase (3) for operating an agricultural unmanned aerial vehicle, “UAV” (1), for distributing an agricultural product to an area over which the UAV travels, the mobile airbase (3) comprising:a frame (32),at least one ground support, in particular a wheel, rotatably connected to the frame (32),32at least one landing platform (31), configured for receiving the UAV (1), andat least one product supply, configured for supplying at least one product to be distributed by the UAV (1),an intermediate tank (360), anda quick transfer channel (363), configured for rapidly transferring product from the intermediate tank (360) to a product tank (170) of the UAV (1).

27. The mobile airbase as claimed in claim 27, further comprising a pressurization system (362) for pressurizing the intermediate tank (360) to provide pressure-assisted transfer of the product from the intermediate tank (360) to the product tank (170).

28. The mobile airbase as claimed in claim 26 or 27, wherein the product supply (351 , 352) comprises:a diluent tank (351),at least one product container (352, 352a, 352b, 352c, 352d), and a product nozzle (3513),the product nozzle (3513) comprising at least one diluent inlet (35132), connected to the at least one diluent tank (351), a product inlet (35133a, 35133b) connected to the product container (352, 352a, 352b, 352c, 352d) and a nozzle outlet (35134),wherein the product inlet (35133a, 35133b) is configured to inject the product into a flow of the diluent.

29. The mobile airbase as claimed in claim 28, wherein the product nozzle is connectable to the intermediate tank (360).

30. A method of operating a UAV (1 ) and a mobile airbase (3), the mobile airbase comprising:a frame (32),33at least one ground support, in particular a wheel, rotatably connected to the frame (32),at least one landing platform (31), configured for receiving the UAV (1), andat least one product supply, configured for supplying at least one product to be distributed by the UAV (1),the method comprising:pre-filling at least one intermediate tank (360) with a product to be transferred from the product supply to the UAV (1),causing the UAV (1) to land on the landing platform (31), connecting a quick transfer channel (363) between the intermediate tank (360) and a tank (170) of the UAV (1 ), andtransferring the product from the intermediate tank (360) to the tank (170) via the quick transfer channel (363).

31. The method as claimed in claim 30, wherein the intermediate tank (360) is pressurized.

32. The method as claimed in claim 30 or 31 , wherein the intermediate tank (360) is positioned at a greater vertical level than the tank (170) of the UAV (1).

33. A method of cleaning an intermediate tank of agricultural product residues, in a system comprising at least one product tank (352, 352a-352d), at least one diluent tank (351), an intermediate tank (360) and an UAV tank (170), the method comprising:supplying diluent from the diluent tank (351) to the intermediate tank (360), andtransferring product-laden diluent from the intermediate tank (360) to the UAV tank (170).3434. The method as claimed in claim 33, wherein said supplying diluent from the diluent tank (351) to the intermediate tank (360) comprises spraying or showering an inside of the intermediate tank (360) with the diluent.

35. The method as claimed in claim 33 or 34, wherein said transferring product-laden diluent from the intermediate tank (360) to the UAV tank (170) comprises spraying or showering an inside of the intermediate tank (360) with the product-laden diluent.

36. The method as claimed in any one of claims 33-35, wherein said supplying diluent from the diluent tank (351) to the intermediate tank (360) and transferring product-laden diluent from the intermediate tank (360) to the UAV tank (170) are repeated with volumes smaller than a UAV tank volume, and in particular volumes which are a unit fraction of the UAV tank volume.

37. The method as claimed in any one of claims 33-35, further comprising spreading the product-laden diluent to an area over which the UAV (1) is travelling.

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