Method of determining clogging of spray nozzles of agricultural spraying system

Abstract

To distinguish objects to be sprayed from objects not to be sprayed near the objects to be sprayed while spraying a cultivated field with chemicals or the like.SOLUTION: The present invention relates to a method of selectively spraying an area of a cultivated field (10) with an agriculture spraying vehicle. The vehicle comprises spraying equipment (200) having at least one imaging system (210), and at least one trailing spray bar (300) comprising a plurality of electromechanical nozzles (310) spaced apart from each other by a constant pitch distance. The agriculture spraying equipment (200) further comprises a control unit (220) including a processing unit to control the electromechanical valve of each electromechanical nozzle (310).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the field of treating agricultural plants, and more particularly to a selective application method using high-precision and high-resolution spot spraying.

Background Art

[0002] Spot spraying is the function of applying liquid droplets to specific predetermined locations. This endeavor has recently emerged as a way to significantly reduce the amount of pesticides in agriculture. In fact, the application of chemicals in agriculture is currently carried out by continuously operating nozzles. All objects on the nozzle's trajectory are sprayed. Modulation techniques such as PWM-based nozzle flow control can contribute to dose reduction and optimization, but do not fundamentally change the problems of standard sprayers that use non-target applications. Spraying chemicals everywhere is an inefficient treatment process, leading to increased costs, increased residual chemicals in the soil and plants, harm to biodiversity, damage to crop yields due to phytotoxicity, and increased amounts of water being transported.

[0003] In spot spraying, the nozzle is equipped with an electromechanically controlled valve that can very quickly switch the flow on and off. The flow is initially set to off and only turns on when targeting for spraying. This enables a significant reduction in chemicals and also reduces costs. The residues of chemicals, contamination of water and soil, and harmful consequences to biodiversity are significantly reduced. Finally, when the crops are slightly sprayed, the phytotoxicity due to limited selectivity is significantly reduced, and healthier crops with excellent pest resistance are obtained, thereby increasing crop yields.

[0004] Whether it is continuous spraying or spot spraying, in spray applications, two important variables need to be controlled to ensure the effectiveness of the application. The first variable is the droplet size, which fundamentally affects how the liquid interacts with the target. In most applications to plants, the desired effect is the absorption of the liquid by the plant's leaves (or, more precisely, the absorption of the active molecules carried by the transport liquid, which is universally water). To obtain good absorption, the droplets must be of a controlled size. If they are too small, they will evaporate in the air or be carried away by the wind before reaching the target. If they are too large, the droplets will roll over the plant without penetrating it. The second variable is the dosage or amount of liquid applied per unit area.

[0005] Two variables affect the droplet size. The two variables are the spraying pressure (the higher the liquid velocity, the more fragmented and smaller the droplets) and the nozzle shape (divergence angle, shape of the spray pattern, flow rate, shape of the nozzle outlet, etc.). Usually, since the nozzles are machined and fixed, these variables cannot be changed in situ. The divergence angle and the flow rate are fixed and are only affected by the pressure. The pressure is usually constant and is fixed at a value that produces the ideal droplet size. Multiple nozzles are usually mechanically exchangeable to suit different application methods with different droplet sizes and application speeds. For this purpose, systems with manual or automatic switching between multiple different nozzles have been developed. However, these changes are usually made from one field to another, from one crop to another, or from one type of application to another (herbicides, fungicides, etc.), but during field operations, the nozzles are fixed.

[0006] In conventional agricultural spraying applications, multiple nozzles are arranged on a spray bar that is orthogonal to the displacement direction of the vehicle to which they are attached and aligned parallel to the surface to be sprayed. The nozzles are characterized by a spray angle that diverges to evenly apply liquid to the surface to be sprayed, generally the ground, but may also be the leaves of vertical plants sprayed laterally. The nozzles are usually spaced apart from each other at a uniform pitch distance. Their divergent jets will enable the application of liquid to a given surface, which depends on the distance from the nozzle to the target (usually the height distance from the nozzle to the ground or the plant).

[0007] Normally, this height is selected such that the application width corresponds to the nozzle spacing, eliminating spray overlap and spray leakage areas. However, the application distance, usually the height, can also be increased, in which case the adjacent nozzle sprays overlap. Thus, the dosage applied per unit area depends not only on the flow rate of each nozzle but also on the nozzle density per unit length given by the nozzle pitch distance between nozzles. The height affects the overlap but not the dosage. Clearly, the dosage is also inversely proportional to the speed of the vehicle.

[0008] Control of the spraying liquid per unit area is basically important in the efficiency of application. In a spraying configuration with a constant and fixed nozzle flow rate and a fixed nozzle spacing, the remaining control variable is only the speed of the vehicle. In practice, this is a preferred control variable when the farmer wants to change the application dosage per unit area. In fact, farmers cannot easily change the nozzles, the density on the spray bar (nozzle pitch distance), the operating pressure, and the recommended spraying speed of the mixture. Farmers also have some freedom regarding the dilution of the active ingredient, but within the allowable range specified by the chemical manufacturer and the operating conditions (temperature and humidity).

[0009] Decades ago, pulse width modulation (PWM) was introduced into sprayers, enabling better dosage control. In this technology, electromechanically operated valves are placed in front of each nozzle and their flow can be quickly switched on and off. The duty cycle of the injection (the duration of the injection opening over the total duration) can be changed from a minimum level to a full nozzle opening in order to vary the average applied nozzle flow rate. For a homogeneous application, this process step must occur at a relatively high switching frequency, and the limit is the opening and closing speed of the electromechanically controlled valves. This technology enables the disposal of another variable for controlling the flow rate, and thus the dosage per unit area, independently of the speed of the sprayer. This, for example, allows for reducing the flow inside the spray bar and increasing the flow outside it, considering the radius of the U-turn with the sprayer, to maintain a uniform application rate across the ground.

[0010] In contrast to the above-described conventional spray applications where the liquid is applied everywhere in a uniform manner and all nozzles spray together, in spot spray applications, the liquid is applied only to some specific plurality of targets (a part of one plant, the whole plant, a group of plants, a part of the ground or other targets). Therefore, in order to accurately control the location where the product is applied, the system needs to position the nozzles accurately and perform a very short spraying operation that is a pulse of a predetermined duration. When the spray diverges, i.e., when small droplets are required, the size and shape of the spray spot are determined by the divergence angle, the distance to the target, and the shape of the nozzle pattern. Placing the nozzle close to the target results in a small spot but a higher dosage per unit area. Placing the nozzle at a greater distance results in a larger spot but a lower dosage per unit area.

[0011] When the machine is moving, its movement changes the dosage per unit area. For example, consider a 5x5 cm square spray pattern and a 25 millisecond spray pulse duration. If the machine is moving at 2 m / s, the spray moves 5 cm during the 25 milliseconds of the pulse, so the square does not remain square. The spot is 5x10 cm in size, so the dosage per unit area is on average divided by 2. Another effect of movement is that, considering the time it takes for the flow to fly from the nozzle to the target, the nozzle needs to be opened before passing vertically through the target. This time is the spraying distance divided by the spraying speed. The same time needs to be used to predict the opening of the nozzle before it passes vertically through the target. Due to the movement of the vehicle, this time is converted into an expected distance equal to the vehicle speed multiplied by the time.

[0012] To accurately position the nozzle for spraying, it is necessary to control its horizontal and vertical positions. In the vertical direction (the direction in line with the movement of the vehicle), the position of the spraying operation is determined only by the correct timing between image acquisition (where the position of the target is identified) and spraying. By controlling the exact moment when the injection opens, knowing the vehicle speed, its position can be accurately controlled. The horizontal position can be controlled by moving the nozzle horizontally. In practice, it is complex to achieve this, and an array of fixed high-density nozzles is preferred. The pitch, that is, the distance between two adjacent nozzles, is important for determining the possible discrete positions of the injection. Their positioning accuracy relative to the ground or plants can be much higher than the pitch, but the possible positions of the injection are determined by the arrangement of the nozzles along the spraying bar. Clearly, the smaller the pitch, the better the control of the horizontal position of the injection.

[0013] Briefly, application rate control, or the amount of liquid applied per unit area, is important for any spraying application. In conventional sprayers, the horizontal density, flow rate, and pressure of the nozzles are fixed, and the application rate can only be controlled by the speed of the nozzles on the ground. By adding PWM control of the nozzle flow rate, the application rate can be controlled independently of the vehicle speed. In the case of spot spraying, two more variables affect the application rate. The first variable is the duration of the impulse opening, and the second variable is the height from the nozzle to the ground.

[0014] For any sprayer, a common problem is nozzle clogging, which is promoted by small-flow nozzles. To prevent clogging, the usual method is to use filters to retain particles of a size sufficient to block the flow. These filters are used either for each nozzle, at the level (height position) of the pressure system, or both. Since nozzle clogging cannot be easily observed by farmers and can occur at any time, it is important for reliable spraying operations to simply and ideally automatically detect nozzle clogging.

[0015] Finally, although the control of the application rate can be efficiently implemented, in order to provide information to the user of the sprayer, whether directly or indirectly involved, and to ensure that the approved application rate per unit area is respected, the measurement of the application rate is desired. Direct measurement of the application rate measures the amount of liquid applied, knows the area processed by the machine, and calculates the application rate per unit area. Indirect measurement of the application rate counts the time the nozzles are open and extrapolates the application rate based on the known nozzle flow rate.

[0016] Patent Document 1 describes a spraying system for controlling the application rate used in a conventional spraying system (continuous spraying) that uses two nozzles together to spray in the same range, one with a constant flow rate and the other with a variable flow rate, modulated by PWM. The PWM ratio is controlled as a function of the slope height and the system pressure to ensure the desired flow rate, which is also measured.

[0017] Patent Document 2 describes a spraying system in which a plurality of spraying bars equipped with nozzle combinations can be assembled overlapping each other or otherwise.

[0018] Patent Document 3 describes a combination of a plurality of nozzles that are controlled by an electric valve and operate in combination to provide a wide range of spraying flows. This system combines the continuous operation and PWM operation of two composite nozzles aligned in the forward direction of spraying. Also, the spraying flow is adjusted using the injection overlap of adjacent nozzles. The algorithm for mode selection is implemented to control the deposition rate considering vehicle speed, desired imprint acceleration, modulation map, and bar height. By controlling the number of nozzles in operation, duty cycle, and nozzle mode (continuous or PWM), the flow rate can be controlled over a wide range to compensate for fluctuations in pressure or speed. All of these settings operate in continuous flow mode.

[0019] Patent Document 4 describes a system for controlling the spraying flow rate that uses PWM individually at each nozzle and calculates the duty cycle as a function of a plurality of variables such as vehicle speed, bar height, turning radius, modulation map, etc.

[0020] These systems have the disadvantage of uniformly spraying chemicals on cultivated land, resulting in a large amount of chemical residues in the soil and plants, and damaging biodiversity and crop yields.

Prior Art Documents

Patent Documents

[0021]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0022] The object of the present invention is therefore to provide a method for selectively spraying on arable land using the relationship of plant characteristics, enabling the application of a chemical to a predetermined plant and avoiding the application of the chemical to other predetermined plants.

[0023] Another object of the present invention is to provide a method for detecting clogging of the spraying nozzles of an agricultural spraying system.

Means for Solving the Problems

[0024] These objects are particularly achieved by a method for selectively spraying an area of arable land with an agricultural spraying vehicle. The vehicle comprises spraying equipment having at least one imaging system and at least one subsequent spraying bar aligned along a direction perpendicular to the direction of the agricultural spraying vehicle during operation. The subsequent spraying bar comprises a plurality of electromechanical nozzles arranged at a constant pitch distance and spaced apart from each other and configured to selectively spray the area. The plurality of electromechanical nozzles comprise a corresponding plurality of nozzles and a corresponding plurality of electromechanical valves. The agricultural spraying equipment further comprises a control unit comprising a tank and a pressure system and a processing unit for controlling the electromechanical valves of each electromechanical nozzle. The method comprises i) obtaining, by means of at least one imaging system, an image of an area of arable land and distinguishing, by means of the processing unit, the plants to be sprayed from the plants not to be sprayed on the image; ii) determining at least one nozzle arranged substantially vertically above the plants to be sprayed; iii) calculating a spraying pattern on the area based on the divergence angle of the at least one nozzle and the vertical distance between the nozzle and the area to be selectively sprayed, the spraying pattern covering the plants to be sprayed and possibly touching the plants not to be sprayed; iv) calculating a distance, an injection shift distance, by which the spraying pattern is shifted laterally so that the shifted spraying pattern covers the plants to be sprayed without covering the plants not to be sprayed, and expressing the injection shift distance as a multiple of the nozzle pitch; v) By shifting at least one nozzle positioned vertically above the plants to be sprayed by the injection shift distance in the lateral direction, the spraying pattern is shifted laterally by the injection shift distance, so that the spraying pattern from the at least one newly selected nozzle is not sprayed onto the plants that should not be sprayed. Comprising.

[0025] In one embodiment, the mask defining the plants to be sprayed extends radially in all directions to determine the expansion area to be sprayed, and ensures that the corresponding plants are correctly sprayed even in the presence of inaccuracies in the lateral position of the selected nozzles or the opening and closing moments of the nozzles.

[0026] In one embodiment, the mask defining the plants to be sprayed is contained within the corresponding plants to be sprayed to determine the reduced area to be sprayed, even in the presence of inaccuracies in the lateral position of the selected nozzles or the opening and closing moments of the nozzles.

[0027] In one embodiment, the opposite side in the lateral direction of the expansion area or the reduced area is reduced by a distance corresponding to the injection shift distance in the lateral direction, and a laterally reduced spraying area is determined so as not to drop the spraying pattern outside the radially expanded area or the reduced area corresponding to the plants on which the lateral injection divergence is sprayed.

[0028] In one embodiment, a buffer area is calculated around the plants identified as non-spray targets by at least one imaging system. The buffer area cuts out a part of the reduced spraying area and determines an even more reduced spraying area.

[0029] In one embodiment, the control unit controls one or more electromechanical valves of the electromechanical nozzles as follows i) The shift pattern described above, ii) The speed of the agricultural spraying vehicle, iii) The height of the spraying bar on the cultivated land, iv) the pressure of the liquid in the spray bar provided by the pressure system, and v) the volume per unit area applied are used to select and open.

[0030] In one embodiment, the electromechanical valves of a plurality of electromechanical nozzles are controlled to open the spray nozzles so as to apply a dosage volume in the range of 25% to 100% of the total spray volume according to any one of the following configuration modes a to f. a Open all the nozzles of the spray bar to spray 100% of the total dosage. b Open every three adjacent spray nozzles of the spray bar. Here, one spray nozzle is closed for every three adjacent spray nozzles to spray 75% of the total dosage. c Open every two adjacent spray nozzles of the spray bar. Here, one spray nozzle is closed for every two adjacent spray nozzles to spray 66% of the total dosage. d Open every other one of two adjacent nozzles of the spray bar to spray 50% of the total dosage. e Open every other one of three adjacent spray nozzles of the spray bar to spray 33% of the total dosage. f Open every other one of four adjacent spray nozzles of the spray bar to spray 25% of the total dosage.

[0031] In one embodiment, in order to improve the accuracy of the total applied volume per unit area, the selection and opening of one or more electromechanical valves of the corresponding nozzles are combined with PWM to further modulate the spray dosage.

[0032] In one embodiment, the selection and opening of one or more electromechanical valves of the corresponding nozzles change periodically between consecutive PWM pulses to obtain an interleaved spot spray pattern with improved application homogeneity.

[0033] In one embodiment, one of two adjacent nozzles is open during the first PWM pulse, and one of the two adjacent nozzles is open during the second PWM pulse.

[0034] In one embodiment, the spraying equipment includes at least two spraying bars arranged parallel to each other. Each spraying bar is provided with a plurality of electromechanical nozzles. The nozzles of each spraying bar are arranged at a certain pitch distance and separated from each other. One spraying bar is laterally shifted from the other spraying bar by a distance equal to half of the pitch distance.

[0035] In one embodiment, the spraying equipment includes at least three spraying bars arranged parallel to each other. Each spraying bar is provided with a plurality of electromechanical nozzles. The nozzles of each spraying bar are arranged at a certain pitch distance and separated from each other. One spraying bar is laterally shifted from one of the two other spraying bars by a distance equal to one-third of the pitch distance, and one spraying bar is laterally shifted from the other of the two other spraying bars by a distance equal to two-thirds of the pitch distance.

[0036] Another aspect of the present invention relates to a method for selectively spraying a cultivated area using an agricultural spraying vehicle equipped with spraying equipment. The spraying equipment includes at least one imaging system and at least two spraying bars arranged parallel to each other. Each spraying bar is provided with a plurality of electromechanical nozzles including corresponding nozzles and corresponding electromechanical valves. The nozzles of each spraying bar are arranged at a certain pitch distance and separated from each other. One spraying bar is laterally shifted from the other spraying bar by a distance equal to half of the pitch distance. The agricultural spraying equipment further includes a control unit including a tank and a pressure system per spraying bar and a processing unit for controlling the electromechanical valves of each electromechanical nozzle of each spraying bar. This method includes i) operating one of the two spraying bars in a first mode where both spraying bars are independent of each other and each spraying bar sprays different products at different locations, or ii) operating the two spraying bars together, considering them as a single bar with the lateral spatial nozzle density doubled, and spraying the same product in a second mode and includes either of them.

[0037] In one embodiment, the spraying equipment includes at least three spraying bars arranged in parallel with each other, and each spraying bar is provided with a plurality of electromechanical nozzles. The plurality of nozzles of each spraying bar are arranged at a certain pitch distance and separated from each other. One spraying bar is laterally shifted from one of the two other spraying bars by a distance equal to one-third of the pitch distance, and one spraying bar is laterally shifted from the other of the two other spraying bars by a distance equal to two-thirds of the pitch distance.

[0038] Another aspect of the present invention relates to a method for determining clogging of the spraying nozzles of an agricultural spraying system. The agricultural spraying system includes a tank and a pressure system, a main electromechanical valve attached downstream of the tank and the pressure system, and a spraying bar including a plurality of electromechanical nozzles each provided with a nozzle and an electromechanical valve downstream of the main electromechanical valve. This spraying bar includes a conduit extending from the main electromechanical valve and communicating with each electromechanical valve of the plurality of electromechanical nozzles, a pressure buffer in fluid communication with the conduit of the spraying bar, and a pressure sensor arranged to measure the pressure in the conduit. This method includes a step of closing any electromechanical valve of the plurality of electromechanical nozzles when it is in an open state; b a step of closing the main electromechanical valve to isolate the spraying bar from the tank and the pressure system; c a step of measuring the pressure p1 in the spraying bar; d a step of actuating the electromechanical valve to open a single electromechanical nozzle K for a certain period of time; e a step of measuring the pressure p2 in the spraying bar and comprises. If the difference between the pressure p1 measured in step c and the pressure p2 measured in step e exceeds a predetermined threshold depending on the absolute pressure p1, the nozzle k is considered not to be clogged. If the difference is below the given threshold, the nozzle k is considered to be at least partially clogged.

[0039] 1. In one embodiment, steps c through e are repeated for each nozzle (k + 1, ..., K + i..., k + n) and the plurality of electromechanical nozzles.

[0040] 1. In one embodiment, if the pressure p2 measured in step e is below a predetermined minimum pressure, the main electromechanical valve opens to fill the pressure buffer before repeating steps c through e.

[0041] 1. In one embodiment, the pressure buffer is an elastic pressure buffer element having a known relationship proportional between the pressure in the buffer and the volume of liquid stored in the buffer.

[0042] Another aspect of the present invention relates to an agricultural spraying vehicle equipped with an agricultural spraying system. The agricultural spraying system includes a tank and a pressure system, a main electromechanical valve attached downstream of the tank and the pressure system, and a spraying bar including a plurality of electromechanical nozzles each having a nozzle and an electromechanical valve downstream of the main electromechanical valve. The spraying bar extends from the main electromechanical valve and includes a conduit leading to each electromechanical valve of the plurality of electromechanical nozzles, a pressure buffer in fluid communication with the conduit of the spraying bar, and a pressure sensor arranged to measure the pressure in the conduit. The agricultural spraying vehicle further includes a control unit including a processor configured to execute the method as described above, and a display unit configured to display clogging information for each nozzle.

[0043] Another aspect of the present invention relates to a method for controlling the application rate per unit area of an agricultural spraying vehicle moving on a cultivated land, which applies selective spot spraying. The agricultural spraying vehicle is equipped with spot spraying equipment. This equipment includes an imaging system and a subsequent spraying bar arranged perpendicular to the movement of this equipment. The spraying bar is provided with a plurality of electromechanical nozzles arranged at a certain pitch distance from each other. The plurality of electromechanical nozzles each include a nozzle and an electromechanical valve. The spraying equipment further includes a tank and a pressure system with a pressure sensor, a control unit for processing the image to control the electromechanical valves of each electromechanical nozzle, and a spraying bar height control unit for arranging the nozzles at a desired distance from the object to be sprayed. This method is i) obtaining an image of the cultivated land area by the at least one imaging system and distinguishing plants to be sprayed from plants not to be sprayed on the image by the processing unit to obtain a segmented image with a spraying mask and a non-spraying mask; ii) determining the density of operating nozzles per unit length and determining the vertical distance from the nozzle to the target based on the desired volume, vehicle speed, and hydraulic pressure per unit area to be applied to ensure a certain spray overlap; iii) adjusting the flow of the open nozzles by the PWM ratio to obtain the desired volume per unit area to be applied; iv) selecting the maximum distance between the minimum height of the spraying bar determined by the user and the maximum distance between the determined vertical distance from the nozzle to the target; v) moving the spraying bar with the spraying bar height control unit to arrange the nozzles at the determined vertical distance from the nozzle to the target; vi) calculating the lateral spray shift distance corresponding to half of the spray spot width on the ground based on the divergence angle of the nozzle, the liquid pressure, and the previously selected maximum vertical distance; vii) extending the mask of the plants to be sprayed from the input segmented plant image including the mask of the plants to be sprayed and the mask of the plants not to be sprayed at a predetermined distance to obtain an extended spraying mask; viii) Reducing the size of the extended spray mask in the horizontal direction by the calculated horizontal injection shift distance to obtain a reduced spray mask; ix) Further considering the open nozzles and the PWM ratio, and defining a nozzle activation map by the intersection of the trajectory of the nozzles of the spray bar and the mask; X) Converting the nozzle activation map into a time-varying electromechanical valve state vector, and applying a signal to the electromechanical valve based on the time-varying electromechanical valve state vector; comprising.

[0044] In one embodiment, the method further applies a buffer zone that extends radially in all directions around the mask of the plants that should not be sprayed to obtain a non-spray mask.

[0045] In one embodiment, the horizontally reduced spray mask is further trimmed by a buffer distance by a non-spray extended mask resulting from the extension of the mask of the non-spray plants before defining the nozzle actuation map.

[0046] The present invention will be better understood with the help of the description of the embodiments given by way of examples and illustrated by the figures.

Brief Description of the Drawings

[0047]

Figure 1

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Figure 12

[0048] Referring to FIG. 1, an agricultural spraying facility 200 according to one embodiment includes a plurality of imaging devices 210. Each of the plurality of imaging devices 210 has an imaging range that includes each observation area 212 for detecting cultivated plants 12 and non-cultivated plants 14 such as weeds on the cultivated land 10. The spraying facility 200 further includes a spraying bar 300 that follows the imaging device 210. The spraying bar includes a plurality of electromechanical nozzles 310, for example, between 20 and 50.

[0049] Referring to FIG. 2, which shows an agricultural spraying facility 200 in which one unit section of one spraying bar is illustrated, each electromechanical nozzle 310 includes a nozzle 314 and an electromechanical valve 312 configured to switch on and off quickly and with high timing accuracy to control the jet flow of the nozzle 314. These nozzles have a divergent jet (mainly in the lateral direction) for applying micro-droplets to a specific range at a specific distance. A plurality of nozzles are assembled in a row and are usually separated by a given distance, typically uniform, called the nozzle pitch distance, to form the spraying bar 300. The spraying bar is arranged parallel to the area to be sprayed (with the chemical agent). A plurality of spraying bars can be assembled to expand the spraying operation width of the system.

[0050] The spray bar 300 is in fluid communication with the tank and pressure system 230 and is adapted to supply the liquid to be sprayed at a desired pressure to the spray bar 300, and its output forms a common inlet to a plurality of electromechanical nozzles 310 that are separated from each other along the spray bar at a constant pitch. A pressure buffer 332 and a pressure sensor 334 are in fluid communication with the spray bar 300 downstream of the electromechanical valve 330 of the spray input.

[0051] The agricultural spraying equipment 200 further includes a control unit 220 that controls the electromechanical valve 314 of the nozzle 310 to timely switch the on and off of the nozzle using the relationship between the plants 12 and the non-cultivated plants 14 detected by the imaging device 210. The control unit 220 communicates with the spray bar control unit 210. The spray bar control unit 210 detects the distance from the spray bar 300 to the ground to control the actuator to lower or raise the spray bar at a desired distance as a function of the spray range calculated in real time by the control unit 220. The spray range is calculated using (using the relationship as) a function of the plants 12 and the non-cultivated plants 14 (such as weeds) detected by the imaging device 210.

[0052] The agricultural spraying equipment 200 enables control of the distance separating the spray bar 300 from the area on the cultivated land 10 to be sprayed. Generally, this area is cultivated land, but it may also be a vertical cultivation structure or vertical plants with characteristics of lateral spraying. Other angles are possible, but the nozzle injection is usually perpendicular to the area to be sprayed. The spray bar is attached to a moving vehicle with the bar direction perpendicular to the moving direction of the vehicle, and spraying is applied when the nozzles are displaced over the area sprayed at a controllable speed by the agricultural spraying equipment 200.

[0053] A first aspect of the present invention addresses the control of which nozzles to operate in order to spray multiple portions of a target ground while avoiding spraying other nearby multiple portions. The present invention operates nozzles that are good at avoiding spraying unnecessary objects in consideration of the distance from the nozzle to the object and the knowledge (obtained data) of the angle of jet divergence. Usually, the nozzle 350 located directly above the object to be sprayed is selected for spraying. However, due to the angle of divergence, as a result of the operation, it may be sprayed on nearby objects, such as plants. In order to avoid such unnecessary spraying, for the selected nozzle 352 to be operated for spraying, a counter distance 354 corresponding to half of the spraying width is taken at the ground position, which is referred to as the lateral jet shift distance.

[0054] One embodiment comprises a method of independently controlling the switching of each nozzle so as to apply a spraying spot with high spatial accuracy and high dosage control, regardless of the nozzle speed, the nozzle distance to the target, and the hydraulic pressure.

[0055] One embodiment comprises a method of controlling the dosage per unit area using a variable number of nozzles per unit length. This means that the height of the bar from the ground is sufficient to have (achieve) a homogeneous application and overlap rate.

[0056] Referring to FIGS. 3a and 3b, in the case of non-cultivated plants 14, weeds or the like that need to be sprayed (the drug) are laterally adjacent to non-sprayed cultivated plants 12 that should not be the spraying target. Using the distance from the nozzle to the target plant and the divergence of the jet, the lateral shift 354 of the jet is calculated. The lateral shift 354 is a distance corresponding to several times the pitch distance between the nozzles. Instead of operating the nozzle 350 positioned perpendicular to the target plant 14, the next nozzle 352, the distance to which from the vertical nozzle 350 corresponds to the lateral shift distance 354, is selected for spraying. As a result, the spraying pattern 320 on the ground is shifted so that it no longer extends over the cultivated plants 12.

[0057] The following table shows the dosages obtained as a function of multiple opening and closing patterns of the nozzles. Clearly, the larger the pattern, the higher the spray bar must be from the ground to maintain a homogeneous application. The right column shows the minimum height of the spray bar, indicated as a multiple of the minimum height, that achieves the optimal overlap when all nozzles are in operation.

[0058]

Table 1

[0059] The configurations of these different patterns are schematically shown in FIGS. 4a to 4d. FIG. 4a shows the nozzles of the spray bar or a part of the spray bar (100% of the flow rate per unit length of the spray bar) when all nozzles are operating, corresponding to a nozzle density pattern of 1111. The numbers indicate the number of injections made by the spray. This also corresponds to the injection overlap rate. An overlap rate of 2 is obtained at a distance of 2h, and an overlap rate of 3 is obtained at a distance of 3h. The uniformity of application is obtained at distances of h, 2h, 3h, and 4h for overlap rates of 1, 2, 3, and 4, respectively.

[0060] FIG. 4b is a figure similar to FIG. 4a, but with a content of using 3 nozzles for 4 sprays (75% of the flow rate, pattern 1110). The uniformity of application is obtained at a distance of 4h for an overlap rate of 3.

[0061] FIG. 4c is a figure similar to FIG. 4b, but with a content of using 2 nozzles for 3 sprays (66% of the flow rate, pattern 110). The uniformity of application is obtained at a distance of 3h for an overlap rate of 2.

[0062] FIG. 4d shows a figure similar to FIG. 4c, but with a content of using 1 nozzle and 1 nozzle for 2 sprays (50% of the flow rate, pattern 10). The uniformity of application is obtained at distances of 2h and 4h for overlap rates of 1 and 2, respectively.

[0063] Another aspect of the present invention is to use height for dosage adjustment. Height is not usually used for dosage control because it affects overlap in a standard spray bar, but the dosage per unit length is given by nozzle density and flow rate. However, in the case of spot spraying, the dosage per unit area is more directly controlled by height and affects the area of the spray.

[0064] Referring to FIG. 5, the relationship between the pattern of operating nozzles and their respective distances from the ground is shown from left to right. First, two adjacent nozzles operate (distance p between operating nozzles). To spray the entire ground without overlap of the sprays, the distance from the nozzles to the ground needs to be h. Second, two nozzles operate at a separation distance of 2p. In this case, to obtain complete coverage of the ground by the sprays without overlap, the distance from the vertical nozzles to the ground needs to be 2h. Third, since the nozzle distance is 3p, the ideal height must be 3h. Finally, on the right side, the nozzle distance is 4p, and to obtain complete ground spraying without overlap, the distance from the nozzles to the ground needs to be 4h.

[0065] Another aspect of the present invention is to combine PWM with spray overlap and adjust the PWM ratio using speed and height information. One common method of adjusting the dosage of a spraying system is to employ high-speed on and off operations of the nozzles. By reproducing at a ratio of on and off states (pulse width modulation), the flow rate can be changed. One aspect of the present invention is to use PWM in combination with the spray overlap rate for controlling the dosage per unit area. This allows for more granularity in dosage control for a given speed, a given height, and a given spray overlap pattern.

[0066] The following table shows possible combinations of spray overlap patterns and PWM ratios, ensuring continuous dosage control between 33% and 100% of the dosage at a given speed. The height needs to be at least three times the minimum height required to avoid overlap with all nozzles in operation.

[0067]

Table 2

[0068] In an embodiment as shown in FIG. 6, the vertical distance between the distal end of the nozzle connected to the spraying bar 300 and the ground makes the lateral spot spraying dimension twice the nozzle pitch. Spraying pattern A shows the case of spot spraying using a spatial combination of a plurality of continuous spraying operations that avoid overlap of the jets and whose overall width corresponds to the width of the object to be sprayed. Spraying pattern B shows the case of spot spraying obtained at the center of the spot where an overlap of factor 2 of the jets is desired. Spraying pattern C is obtained by adjacent PWM sprays that are all horizontally aligned and show no horizontal overlap between them. Between consecutive PWM pulses, the actuated nozzles are shifted horizontally by one unit (interleaved spot spraying) by one unit to provide better spraying homogeneity. Spraying pattern D is obtained by PWM pulses interleaved with an overlap of factor 2. The PWM duty cycle is selected to be shorter than in example C. Spraying pattern E is obtained when all nozzles are turned on simultaneously and creates a spraying line. Keeping the nozzles on results in a continuous spraying operation as in a conventional sprayer (without spot spraying).

[0069] Another aspect of the present invention is to use an interleaving (or horizontal shifting of selected nozzles) between two consecutive PWM pulses in order to better homogenize the dosage. One of the problems with PWM is that the flow is interrupted and the uniformity of the applied dosage is lost. To help reduce this effect, one aspect of the present invention is to shift the spraying pattern horizontally by one nozzle pitch between two PWM pulses in order to obtain an interleaved (or mosaic) position at the center of the spot, resulting in better homogeneity. This method can also be used without PWM and helps to properly position the spraying shape horizontally by an increment of one nozzle pitch. This method can be used with different PWM ratios between two consecutive switching operations and further enhances the dynamic characteristics of dosage control.

[0070] Another aspect of the present invention is to use interleaved PWM with vertical injection overlap to better homogenize the dosage. The above-mentioned tool can actually control the dosage in combination with the injection overlap. This is obtained by vertically overlapping two consecutive (and thus interleaved) spraying patterns. Thereby, the range of dosage control can be expanded. The distance between the nozzle and the ground necessarily creates some drift of the droplets, which helps to make the dosage per unit area uniform.

[0071] Another aspect of the present invention is to control and manage the extension of spraying around a given target in spot spraying applications. The target of spraying, such as a plant, must sometimes be completely covered at the spraying spot. To ensure this even in the presence of positioning errors, the system needs to spray with a defined radial extension of the spraying area around and outside the target. Thereby, even with errors in the opening and closing timing of the nozzle or the lateral position of the nozzle, the entire target area can be sprayed.

[0072] The same applies to the radial reduction of the target range, resulting in an application that is strictly confined within the target range. This is necessary, for example, when it is guaranteed that the product sprayed during application reaches only one target and no product is applied behind or outside the target range. When the boundary of the target is radially reduced, the sprayed spot completely enters within the characteristic range of the plant (e.g., leaves).

[0073] Yet another aspect of the present invention is to apply a buffer (exclusion) area around the target that should not be sprayed, ensuring that spot spraying does not touch plants located within the buffer area even with some spraying inaccuracies. The buffer area can be defined around the target using an exclusion function. This means that spraying on the target must be absolutely avoided. Thus, the spraying system can define a geometry that surrounds the geometry of a given target of any shape with a certain overlap distance. This "buffer" geometry is then used as the exclusion area of the spraying system.

[0074] Figures 7a through 7f show different spreading patterns from this perspective. For example, Figure 7a shows a top schematic view of a part of a cultivated field including a plant 14 to be spread and a plant 12 not to be spread. Figure 7b shows the shape of the object to be spread extended in the radial direction by a distance 52 to present an extended area 50 to be spread. Figure 7c shows an extended area that shrinks horizontally by a horizontal distance 54 corresponding to a horizontal injection shift distance and a distance 55. Figure 7d shows the shape of the (cropped) result further cut out by a safety protection buffer distance created around the object not to be spread, preventing the injection from touching it. Figure 7e shows the intersection of the nozzle trajectory on the cultivated field and the spread shape, forming a section 62 where the nozzle operates between the intersections. Figure 7f shows a spread pattern 64 obtained in two nozzle operation sections.

[0075] In the embodiment shown in FIG. 8, a combination of two spraying bars with the same nozzle pitch distance is used in parallel and close to each other. The second bar 304 is laterally shifted by half of the nozzle pitch distance 306 from the first bar 302. With this implementation, the spraying system can be operated in so-called dual-mode spraying. In the first mode, the two spraying bars operate independently of each other and spray different products in different locations. They can both operate in continuous spraying mode, or both in spot spraying mode, or the first one in spot spraying mode and the second one in continuous mode, or vice versa. In this mode, since each bar has its own pressure system, both bars can be adjusted independently with respect to the dosage per unit area, bar height, and bar pressure. In the second mode, the two spraying bars are operated together and spray the same liquid at the same pressure. The lateral shift by half of the nozzle pitch between the two bars reduces the lateral distance between two nozzles by half, improving the lateral spraying space resolution by a factor of two. The fact that the nozzles are not arranged in a single line must be compensated for by appropriate timing attenuation between the openings of the first bar nozzles and the second bar nozzles. Multiple spraying examples obtained by dual-mode spraying are illustrated. To obtain spraying patterns A and B, the two bars are combined to perform spot spraying with different PWM duty cycles. To obtain spraying patterns C and D, they (the two bars) are used to perform spot spraying on separate targets. To obtain spraying pattern E, they are used together to perform spot spraying with the maximum overlap ratio.

[0076] The above combination of two spraying bars for enhancing lateral accuracy can be further extended to three or more spraying bars that are shifted from each other by one-third or one-fourth of the nozzle pitch distance. In this case, the lateral accuracy increases in a ratio corresponding to the number of spraying bars.

[0077] Another aspect of the present invention is to provide a method for controlling the dosage applied per unit area. This method can be operated in both continuous spraying operations and spot spraying operations. This method may be operated with a single spraying bar, or in combination with two spraying bars shifted horizontally by half the nozzle pitch to form a double lateral resolution spraying system, either independently or together.

[0078] As shown in FIG. 9, this method receives, as input, a segmented plant image containing plant species, using a basic spraying rule applied to each plant. The basic spraying rule means which plant species to spray or not to spray, and which liquid to use when the system has two or more different spraying bars with different products on each bar. Next, safety protection buffers for each plant species and each product to be sprayed, as well as expansion or reduction values, are also received as input values. The desired dosage per unit area applied to each product to be sprayed is also received as an input value (which can follow multiple local variations provided by a so-called spraying modulation map). Finally, a certain number of variables that affect the dosage applied per unit area, such as the minimum desired distance or height of each spraying bar from the ground or target, the movement and speed of the vehicle, and the pressure of each spraying bar liquid, are received as input values.

[0079] This method generates multiple output results for controlling the dosage applied. The main output result is the state vector of the nozzle electromechanical valves, which is a vector of the on and off states of each nozzle electromechanical valve of the controlled spraying bar. The second output result is the height of the spraying bar, which is supplied to the control unit for the height of the spraying bar. The third output result is a spraying amount map indicating the amount of liquid sprayed per unit area.

[0080] This method comprises four main operations, which are detailed below with reference to FIG. 10.

[0081] The first operation calculates the nozzle density pattern and the PWM ratio to apply the desired dosage per unit area. This calculation uses the vehicle speed, the pressure of the spray bar, and the desired dosage to be applied (which may vary according to the tillage map). In the calculation, the PWM is first set to 60%, and a nozzle density pattern smaller than desired while providing the highest flow rate is selected to obtain the dosage expected at the operating speed and pressure required by the user and the minimum spray bar height (with all nozzles open, or 3 out of 4 nozzles open, or 2 out of 3 nozzles open, etc.). Next, the height is increased to the recommended height as needed to provide uniform application with the selected nozzle density pattern. The corresponding dosage is calculated, and finally the PWM is calculated (increased) to obtain the ultimately required dosage.

[0082] The second operation of this method calculates the lateral injection shift distance used in the third operation. For this, the maximum of the minimum height of the spray bar (required by the user) and the height of the nozzle density pattern resulting from the spray bar is selected. This height value is used to calculate the lateral injection shift distance based on the nozzle injection angle that depends slightly on the pressure of the spray bar.

[0083] The third operation of this method acquires the input (value-based) segmented image of multiple plants and generates a spray map from it. First, the specified radial zoom value is applied to the shape of the target object. Then, the extension mask is horizontally shrunk by the previously calculated lateral injection shift distance. Next, a safety protection buffer distance is applied around the non-target objects to prevent the spray agent from touching them, and the overlap mask is cut out if it is in this buffer area. Then, the obtained and cut-out shape is intersected with the nozzle trajectory (in the case of dual-mode spray bar operation using two bars together to increase the spatial resolution, the density is doubled), and the intervals for operating the nozzles are obtained. The PWM and nozzle density pattern rules are applied to obtain the nozzle operation map. The latter is ultimately converted into the on and off sequence of the nozzle electromechanical valves (state vector).

[0084] The fourth and final operation of this automatic dosing method is to calculate the amount of liquid applied to a predetermined unit area on the ground based on the final opening time length and pressure of the nozzle electromechanical valve.

[0085] Another aspect of the present invention is the provision of a method for automatically controlling nozzle clogging as shown in FIGS. 11 and 12. This method requires the use of an electromechanical valve 330 at the spray bar inlet that allows the bar 300 to be isolated from the input from the pressure system 230, which also requires the presence of a pressure buffer 332 attached to the spray bar having a relatively linear relationship between pressure and volume, and an accurate and linear pressure sensor 334 for measuring the pressure within the spray bar. This method operates as follows during the clogging control procedure. First, all nozzles 310 are closed, a nominal pressure is established within the bar, and the input electromechanical valve 330 is closed. Second, the hydraulic pressure before and after the opening time of the first nozzle is measured. Given the expected nozzle flow rate, opening time, and the pressure-volume relationship of the pressure buffer, the theoretical pressure loss is calculated and compared to the actual pressure loss. If significantly smaller, the corresponding nozzle is considered clogged and so recorded. The procedure is repeated for all nozzles of the bar, and the pressure of the bar is periodically refilled with opening pulses of the electromechanical valve input to the spray bar. At the end of the operation, this method provides clogging information for all nozzles of the entire spraying system.

Claims

1. A method of selectively spraying a range with a farming spray vehicle having a cultivated land (10), wherein the farming spray vehicle has a spraying facility (200) having at least one imaging system (210); at least one subsequent spraying bar (300) that aligns along a direction perpendicular to the direction of the farming spray vehicle during operation, a plurality of electromechanical nozzles (310) are arranged at a constant pitch distance from each other and are configured to selectively spray the range, and at least one subsequent spraying bar (300) having a plurality of electromechanical nozzles (310) provided with corresponding nozzles (314) and corresponding electromechanical valves (312); and comprising the farming spraying facility (200) has a tank and a pressure system (230); a control unit (220) comprising a processing unit for controlling the electromechanical valves (312) of each electromechanical nozzle (310); and further comprising the method comprising acquiring, by at least one of the imaging systems (210), an image of a range of the cultivated land (10), and distinguishing, by the processing unit, plants (14) to be sprayed from plants (12) that should not be sprayed on the image; determining at least one nozzle (350) that will be disposed substantially vertically above the plants (14) to be sprayed; calculating a spraying pattern on the range based on the divergence angle of the at least one nozzle (350) and the vertical distance between the nozzle (350) and the range to be selectively sprayed, wherein the range is to be selectively sprayed, the spraying pattern covers the plants (14) to be sprayed, and may touch the plants (12) that should not be sprayed, calculating the spraying pattern; calculating a distance, an injection shift distance (354), by which the spraying pattern is shifted horizontally so that the shifted spraying pattern covers the plants (14) to be sprayed without covering the plants (12) that should not be sprayed, and expressing the injection shift distance (354) as a multiple of the nozzle pitch; By shifting at least one nozzle (350) positioned vertically above the plant (14) to be sprayed by the injection shift distance in the lateral direction, the spraying pattern is shifted laterally by the injection shift distance, so that the spraying pattern from at least one newly selected nozzle (352) is not sprayed onto the plants (12) that should not be sprayed. A method for selectively spraying an area of cultivated land (10) using an agricultural spraying vehicle comprising the above. **Claim 2** Even when there is inaccuracy in the lateral position of the selected nozzle or the moment of opening and closing of the nozzle, it is ensured that the corresponding plants (14) are correctly sprayed, and the mask defining the plants (14) to be sprayed extends in all directions radially at a distance (52) determining the extended area (50) to be sprayed. The method according to claim 1. **Claim 3** Even when there is inaccuracy in the lateral position of the selected nozzle or the moment of opening and closing of the nozzle, it is ensured that it is included inside the corresponding plants (14) to be sprayed, and the mask defining the plants (14) to be sprayed is reduced in all directions radially at a distance determining the reduced area to be sprayed. The method according to claim 1. **Claim 4** The lateral opposite sides of the extended area (50) or the reduced area are reduced by a distance (54, 55) corresponding to the injection shift distance in the lateral direction to determine a laterally reduced spraying area (56), and it is ensured that the divergence of the lateral injection does not fall outside the radially extended area (50) of the spraying pattern or the reduced area corresponding to the plants (14) to be sprayed. The method according to claim 3. **Claim 5** A buffer area (57) is calculated around the plant (12) identified as a plant that should not be sprayed by at least one of the imaging systems (210), and the buffer area (57) cuts out a part of the reduced spraying area (56) to determine an even more reduced spraying area (58). The method according to claim 4. **Claim 6** The control unit (220) controls one or more electromechanical valves (312) of the electromechanical nozzles (310) with the shifted pattern, the speed of the agricultural spraying vehicle, the height of the spraying bar (300) on the cultivated land (10), the pressure of the liquid in the spraying bar (300) provided by the pressure system (230), and the volume per unit area applied The method according to any one of claims 1 to 5, which is selected and opened based on the relationship.

7. a A configuration in which all nozzles of the spraying bar (300) are opened to spray 100% of the total dose, b A configuration in which three adjacent spraying nozzles of the spraying bar (300) are opened, where one spraying nozzle is closed for each set of the three adjacent spraying nozzles to spray 75% of the total dose, c A configuration in which two adjacent spraying nozzles of the spraying bar (300) are opened, where one spraying nozzle is closed for each set of the two adjacent spraying nozzles to spray 66% of the total dose, d A configuration in which nozzles are opened one by one for every other one of two adjacent nozzles of the spraying bar (300) to spray 50% of the total dose, e A configuration in which spraying nozzles are opened one by one for every other one of three adjacent spraying nozzles of the spraying bar (300) to spray 33% of the total dose, f A configuration in which spraying nozzles are opened one by one for every other one of four adjacent spraying nozzles of the spraying bar (300) to spray 25% of the total dose The electromechanical valve (312) of the plurality of electromechanical nozzles (310) is controlled to open the spraying nozzles so as to apply a dose volume in the range of 25% to 100% of the total dose according to any one of the above, according to the method according to any one of claims 1 to 6.

8. The selection and opening of one or more of the corresponding nozzles of the electromechanical valve (312) are combined with PWM to further modulate the spraying dose to improve the accuracy of the total applied volume per unit area, according to the method according to any one of claims 1 to 7.

9. The selection and opening of one or more of the corresponding nozzles of the electromechanical valve (312) change periodically between consecutive PWM pulses to obtain an interleaved spot spraying pattern with improved application homogeneity, according to the method according to claim 8.

10. One of two adjacent nozzles is open during the first PWM pulse, and the other of the two adjacent nozzles is open during the second PWM pulse, according to the method according to claim 9.

11. The method according to any one of claims 1 to 10, wherein the spraying device (200) comprises at least two spraying bars (302, 304) arranged parallel to each other, each spraying bar (302, 304) comprises a plurality of electromechanical nozzles (310), the plurality of nozzles (314) of each spraying bar are arranged at a constant pitch distance from each other, and one spraying bar (302) is laterally offset from the other spraying bar (304) by a distance equal to half of the pitch distance.

12. The spraying device (200) comprises at least three spraying bars arranged parallel to each other, and each spraying bar comprises a plurality of electromechanical nozzles (310). The plurality of nozzles (314) of each spraying bar are arranged at a constant pitch distance from each other. One spraying bar is laterally offset from one of the two other spraying bars by a distance equal to one-third of the pitch distance, and the one spraying bar is laterally offset from the other of the two other spraying bars by a distance equal to two-thirds of the pitch distance. The method according to any one of claims 1 to 10.

13. A method for selectively spraying a range of a cultivated land (10) using an agricultural spraying vehicle, wherein the agricultural spraying vehicle comprises a spraying device (200) having at least one imaging system (210); at least two spraying bars (302, 304) arranged parallel to each other, each spraying bar (302, 304) comprising a plurality of electromechanical nozzles (310) each having a corresponding plurality of nozzles (314) and a corresponding plurality of electromechanical valves (312); and the agricultural spraying vehicle further comprises the plurality of nozzles (314) being arranged at a constant pitch distance from each other; one of the spraying bars (302) being laterally offset from the other spraying bar (304) by a distance equal to half of the pitch distance; the agricultural spraying device (200) comprises a tank and a pressure system (230) for each spraying bar; and a control unit (220) comprising a processing unit for controlling the electromechanical valves (312) of the electromechanical nozzles (310) of each spraying bar; the method comprising Operating one of the two spraying bars (302, 304) in a first mode, in which both spraying bars are independent of each other and each spraying bar sprays different products at different positions, operating in the first mode, Operating the two spraying bars in a second mode, in which the two spraying bars are combined together and regarded as a single bar with a lateral spatial nozzle density twice as high to spray the same product, operating the two spraying bars in the second mode A method of selectively spraying a range of a cultivated land (10) using an agricultural spraying vehicle, comprising:

14. The spraying equipment (200) comprises at least three spraying bars arranged parallel to each other, each spraying bar comprising a plurality of electromechanical nozzles (310), A plurality of nozzles (314) of each spraying bar are arranged at a constant pitch distance from each other, One spraying bar is laterally displaced from one of the two other spraying bars by a distance equal to one-third of the pitch distance, and the one spraying bar is laterally displaced from the other of the two other spraying bars by a distance equal to two-thirds of the pitch distance. The method according to claim 13.

15. A tank and a pressure system (230), A main electromechanical valve (330) mounted downstream of the tank and the pressure system (230), A spraying bar (300) comprising a plurality of electromechanical nozzles (310) each having one nozzle (314) and an electromechanical valve (312) downstream of the main electromechanical valve (330), the spraying bar (300) extending from the main electromechanical valve (330) and comprising a conduit reaching each electromechanical valve (312) of the plurality of electromechanical nozzles (310), A pressure buffer (332) in fluid communication with the conduit of the spraying bar (300), A pressure sensor (334) arranged to measure the pressure in the conduit A method for determining clogging of a spraying nozzle of an agricultural spraying system, the method comprising: a Closing the electromechanical valve (312) of the plurality of electromechanical nozzles (310) if the electromechanical valve (312) is open; b Closing the main electromechanical valve (330) to disconnect the spraying bar (300) from the tank and the pressure system (230); c Measuring the pressure p1 inside the spraying bar (300); d Activating one electro-mechanical valve (312) to open a single electro-mechanical nozzle k for a fixed period; e Measuring the pressure p2 inside the spraying bar (300), wherein if the difference between the pressure p1 measured in step c and the pressure p2 measured in step e exceeds a given threshold value that depends on the absolute value of the pressure p1, the nozzle k is considered not to be clogged, and if the difference is below the given threshold value, the nozzle k is considered to be at least partially clogged, the step of measuring the pressure p2; A method for determining clogging of a spraying nozzle of an agricultural spraying system, comprising:

16. The method according to claim 15, wherein steps c to e are repeated for each nozzle (k + 1,..., k + i,..., k + n) of the plurality of electro-mechanical nozzles (310).

17. The method according to claim 16, wherein when the pressure p2 measured in step e is below a predetermined minimum pressure, before repeating steps c to e, the main electro-mechanical valve (330) is opened to fill the pressure buffer (332).

18. The method according to any one of claims 15 to 17, wherein the pressure buffer (332) is an elastic pressure buffer element having a known relationship proportional to the pressure in the buffer and the volume of the liquid stored in the buffer.

19. An agricultural spraying vehicle comprising an agricultural spraying system, wherein the agricultural spraying system comprises: A tank and a pressure system (230); A main electro-mechanical valve (330) mounted downstream of the tank and the pressure system (230); A spraying bar (300) comprising a plurality of electro-mechanical nozzles (310) each having one nozzle (314), and an electro-mechanical valve (312) downstream of the main electro-mechanical valve (330), wherein the spraying bar (300) extends from the main electro-mechanical valve (330) and comprises a conduit reaching each electro-mechanical valve (312) of the plurality of electro-mechanical nozzles (310); A pressure buffer (332) in fluid communication with the conduit of the spraying bar (300); A pressure sensor (334) arranged to measure the pressure in the conduit; In an agricultural spraying vehicle comprising: The agricultural spraying vehicle is A control unit having a processing device configured to execute the method according to any one of claims 15 to 18, A display unit for displaying clogging information of each nozzle An agricultural spraying vehicle further comprising.

20. A method for controlling the application rate per unit area of an agricultural spraying vehicle moving on a cultivated land (10) to which selective spot spraying is applied, The agricultural spraying vehicle is provided with a spot spraying facility (200), The spot spraying facility (200) includes an imaging system (210) and a subsequent spraying bar (300) arranged perpendicular to the movement of the facility, The spraying bar (300) includes a plurality of electromechanical nozzles (310), and the electromechanical nozzles (310) are arranged at a certain pitch distance from each other, and each electromechanical nozzle includes a nozzle (314) and an electromechanical valve (312), The spraying facility (200) further includes a tank and a pressure system (230) provided with a pressure sensor, a control unit (220) for processing an image and controlling the electromechanical valve (312) of each electromechanical nozzle (310), and a spraying bar height control unit (240) for arranging a plurality of the nozzles at a desired distance from a spraying target, The method is, Using the at least one imaging system (210) to obtain an image of a range (212) of the cultivated land (10), and distinguishing, by a processing unit, plants (14) to be sprayed from plants (12) that should not be sprayed on the image to obtain a segmented image having a spraying mask and a non-spraying mask, Determining the density of operating nozzles per unit length based on the desired volume, vehicle speed and liquid pressure per unit area to be applied, and determining the vertical distance from the nozzle to the target to ensure a certain spray overlap, Modulating the flow of the open nozzles with a PWM ratio to obtain the desired volume per unit area to be applied, Selecting the maximum distance between the minimum height of the spraying bar determined by the user and the determined vertical distance from the nozzle to the target, Moving the spraying bar using the spraying bar height control unit (240) to arrange the nozzles at the determined vertical distance from the nozzle to the target Calculating a lateral injection shift distance corresponding to half of the spread spot width on the ground based on the divergence angle of the nozzle, the liquid pressure, and a previously selected maximum vertical distance; Extending the plant spread mask from the input segmented plant image, which includes a mask (14) of the plants to be spread and a mask (12) of the plants that must not be spread, by a distance (52) to obtain an extended spread mask (50); Reducing the size of the extended spread mask (50) laterally by the calculated lateral injection shift distance (54, 55) to obtain a reduced spread mask (56); Further defining a nozzle activation map (62) by the intersection of the nozzle trajectory (60) of the spread bar and the spread mask, taking into account the open nozzle and the PWM ratio; Converting the nozzle activation map into a time-varying electromechanical valve state vector and applying a signal to the electromechanical valve (312) based on the time-varying electromechanical valve state vector; A method comprising the above steps.

21. The method according to claim 20, further applying a buffer area (57) that extends radially omnidirectionally around the mask of the plants (12) that must not be spread to obtain a non-spread mask.

22. The method according to claim 20 or 21, wherein the laterally reduced spread mask (56) is further cut out by an extended non-spread mask resulting from the extension of the mask of the plants (12) that must not be spread by the buffer distance (57) before defining the nozzle activation map.

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