Control of spot spraying of pesticides

Abstract

This specification describes a method for operating a control system that sprays pesticides using a spray assembly. The method includes first determining the position of a first spot spray based on the position of the leading edge of the object, and then determining the initial position of at least one new adjacent spot spray in terms of lateral and longitudinal offsets relative to the first spot spray, such that the combined doses of the first and new spot sprays form a continuous spray zone covering a portion of the object. Next, a two-dimensional dose map obtained from the first and new spot sprays is determined and used to identify whether predetermined dose criteria are met. If these criteria are not met, the method includes adjusting the offset of at least one new adjacent spot spray to optimize the received dose. A control signal for the nozzle array is generated according to the position of the first spot spray and the adjusted offset of at least one new adjacent spot spray and output to the spray assembly.

Description

Technical Field

[0001] The present invention relates to the control of a spraying device for spot spraying pesticides on plants.

Background Art

[0002] Generally, pesticides, regardless of whether they are growth promoters (e.g., fertilizers), growth inhibitors (e.g., herbicides), or those that prevent diseases or pests (fungicides, insecticides, etc.), are sprayed on plants in liquid form using spraying. Pesticides are sprayed through nozzles that can be attached to a spray bar. The spray bar can be attached to a vehicle (e.g., a tractor or a robot), or to a device towed by a vehicle. Continuous spraying sprays pesticides everywhere, and the nozzles operate continuously. In contrast, spot spraying uses a valve (e.g., an electromechanical control valve) that can quickly switch the flow of the pesticide on and off to disperse droplets at specific predetermined locations.

[0003] The use of continuous spraying is often inefficient because pesticides are sprayed in places where they are not needed (e.g., exposed soil), which not only increases costs but also increases chemical residues in the soil, potentially causing various effects including the destruction of biodiversity and an increased likelihood of reduced yields due to phytotoxicity in the sprayed crops. Spot spraying can significantly reduce the amount of pesticide being dispersed. This increases efficiency (since pesticides are only sprayed where needed), reduces the environmental impact (e.g., reducing chemical residues in the soil and water and reducing carbon dioxide emissions due to reduced production and transportation of liquid pesticides), reduces water usage, and improves yields.

Summary of the Invention

[0004] This summary is provided to introduce some of the concepts described further in the detailed explanation in a simplified form. This summary is not intended to identify any important or fundamental features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0005] This specification describes a method for operating a control system that sprays pesticides using a spray assembly. The method includes first determining the position of a first spot spray based on the position of the leading edge of the object, and then determining the initial position of at least one new adjacent spot spray in terms of lateral and longitudinal offsets relative to the first spot spray, such that the combined doses of the first and new spot sprays form a continuous spray zone covering a portion of the object. Next, a two-dimensional dose map obtained from the first and new spot sprays is determined and used to identify whether predetermined dose criteria are met. If these criteria are not met, the method includes adjusting the offset of at least one new adjacent spot spray to optimize the received dose. A control signal for the nozzle array is generated according to the position of the first spot spray and the adjusted offset of at least one new adjacent spot spray and output to the spray assembly.

[0006] The first aspect provides a method for operating a spot spray control system for spraying a pesticide using a spray assembly including an array of nozzles, the method comprising: (i) determining the position of a first spot spray based on the position of the leading edge of an object; (ii) determining the initial position of at least one new adjacent spot spray with respect to the first spot spray such that the combined doses of the first and new spot sprays form a continuous spray zone covering a portion of the object, wherein each of the first and new spot sprays is determined by a non-uniform two-dimensional liquid space distribution, and the lateral offset is a multiple of the effective spacing between nozzles in the array of nozzles; (iii) determining a two-dimensional dose map obtained from the first and new spot sprays; (iv) adjusting the offset of at least one new adjacent spot spray to optimize the received dose in response to determining from the two-dimensional dose map that a predetermined dose criterion is not met; (v) generating a control signal for the array of nozzles according to the position of the first spot spray and the adjusted offset of at least one new adjacent spot spray; and (vi) outputting the control signal to the spray assembly.

[0007] The method may further include, in response to determining from a two-dimensional dose map that the object is not completely covered by the spray zone, repeating steps (ii) to (iv) until the object is completely covered.

[0008] Determining the initial position of at least one new adjacent spot spray relative to the first spot spray in terms of lateral and longitudinal offsets may include determining the initial position of three new adjacent spot sprays relative to the first spot spray in terms of lateral and longitudinal offsets, and adjusting the offset of at least one new adjacent spot spray to optimize the received dose may include adjusting the offset of the three new adjacent spot sprays to optimize the received dose within the quadrilateral defined by the first spot spray and the three new adjacent spot sprays. The method may further include, in response to determining from a two-dimensional dose map that an object is not completely covered by the spray zone, positioning additional spot sprays using the adjusted offsets until the object is completely covered.

[0009] The two-dimensional liquid spatial distribution of a spot spray can be determined based on the static two-dimensional liquid spatial distribution of the nozzle and the received motion data of the spray assembly.

[0010] The two-dimensional liquid spatial distribution of spot spray can be determined based on the static two-dimensional liquid spatial distribution of the nozzle and the detected distance between the nozzle array and the target object.

[0011] The two-dimensional liquid spatial distribution of spot spray can be determined based on the static two-dimensional liquid spatial distribution of the nozzle and the nozzle opening period.

[0012] The two-dimensional liquid spatial distribution of spot spray can be defined using a lookup table.

[0013] The two-dimensional liquid spatial distribution of a spot spray can be determined using a Gaussian distribution or a normal distribution.

[0014] The method may further include adjusting the nozzle opening period in response to changes in the forward speed of the nozzle during spraying to maintain a constant two-dimensional liquid spatial distribution of the spot spray.

[0015] Optimizing the received dose may include ensuring that the received dose consistently exceeds a predetermined minimum dose.

[0016] The method may further include adjusting a predetermined minimum dose based on the size or type of the object.

[0017] Optimizing the received dose may include ensuring that the received dose does not exceed a predetermined maximum dose.

[0018] A second aspect is a spot spray control system for spraying pesticide using a spray assembly including an array of nozzles, comprising a processor, one or more interfaces configured to receive object data and output control signals to the spray assembly, and a memory configured to store a computer program, wherein, when executed by the processor, the computer program (i) determines the position of a first spot spray based on the position of the leading edge of an object, and (ii) determines the initial position of at least one new adjacent spot spray (704, 1204) in terms of lateral and longitudinal offsets relative to the first spot spray, such that the combined doses of the first and new spot sprays form a continuous spray zone covering a portion of the object. A spot spray control system is provided, which causes the spot spray control system to perform the following: (iii) determine a two-dimensional dose map obtained from the first and new spot sprays, (iv) adjust the offset of at least one new adjacent spot spray to optimize the received dose in response to determining from the two-dimensional dose map that a predetermined dose criterion is not met, (v) generate a control signal for the nozzle array according to the position of the first spot spray and the adjusted offset of at least one new adjacent spot spray, and (vi) output the control signal to the spray assembly via one or more interfaces.

[0019] A third aspect provides a method for operating a spot spray control system for spraying a pesticide using a spray assembly including an array of nozzles, comprising: determining the longitudinal offset of a first spot spray, the lateral and longitudinal offsets of one or more new adjacent spot sprays, and the nozzle opening period for each spot spray using a pre-calculated table, wherein each of the first and new spot sprays is determined by a non-uniform two-dimensional liquid space distribution, and the lateral offset is a multiple of the effective spacing between nozzles in the array of nozzles; determining the position of the first spot spray based on the position of the leading edge of an object and the determined longitudinal offset of the first spot spray; determining the positions of one or more new adjacent spot sprays relative to the position of the first spot spray based on the determined lateral and longitudinal offsets of one or more new adjacent spot sprays; generating a control signal for the array of nozzles according to the positions of the first spot spray and one or more new adjacent spot sprays, the opening period for each spot spray, and the nozzle displacement velocity; and outputting the control signal to the spray assembly.

[0020] Determining the longitudinal offset of the first spot spray, the lateral and longitudinal offsets of one or more new adjacent spot sprays, and the nozzle open duration of each spot spray using a pre-calculated table may include performing a lookup within the pre-calculated table to determine the longitudinal offset of the first spot spray, the lateral and longitudinal offsets of one or more new adjacent spot sprays, and the nozzle open duration of each spot spray, based on the velocity of the nozzle array, a predetermined minimum dose, and the input distance between the nozzle and the object.

[0021] The method may further include, in response to determining that the object is not completely covered by the first and new spot sprays, positioning further spot sprays using determined lateral and longitudinal offsets until the object is completely covered.

[0022] The method may further include pre-calculating a table of offsets and nozzle open periods, the table including the longitudinal offset of a first spot spray for different values ​​of velocity, a given dose, pressure, and distance to the object, the lateral and longitudinal offsets of one or more new adjacent spot sprays, and the nozzle open period for each spot spray.

[0023] A fourth aspect is a spot spray control system for spraying pesticides using a spray assembly including an array of nozzles, comprising a processor, one or more interfaces configured to receive object data and output control signals to the spray assembly, and a memory configured to store a computer program, the computer program, when executed by the processor, using a pre-calculated table, determines the longitudinal offset of a first spot spray, the lateral and longitudinal offsets of one or more new adjacent spot sprays, and the nozzle open period for each spot spray, wherein each of the first and new spot sprays is determined by a non-uniform two-dimensional liquid space distribution, and the lateral offset is within the array of nozzles A spot spray control system is provided, which causes the spot spray control system to perform the following: determine the position of a first spot spray based on the effective spacing of the nozzles, the position of the leading edge of the object, and the determined longitudinal offset of the first spot spray; determine the positions of one or more new adjacent spot sprays relative to the position of the first spot spray based on the determined lateral and longitudinal offsets of one or more new adjacent spot sprays; generate a control signal for the nozzle array according to the positions of the first spot spray and one or more new adjacent spot sprays, the opening period of each spot spray, and the nozzle displacement velocity; and output the control signal to the spray assembly via one or more interfaces.

[0024] A fifth aspect provides a computer program that includes instructions causing a computer to perform one of the methods described above when executed by the computer.

[0025] A sixth aspect provides a computer-readable medium storing a computer program including instructions that, when executed by a computer, cause the computer to execute any of the methods described above.

[0026] The methods described herein can be implemented in the form of a computer program, such as a computer program including computer program code means adapted to perform all the steps of any of the methods described herein when executed on a computer, in a machine-readable form on a tangible storage medium, such as software on a tangible (or non-transitory) storage medium, examples of which include disks, thumb drives, memory cards, etc., and not including propagated signals. The software can be suitable for execution on a parallel processor or a serial processor such that the method steps can be executed in any suitable order or simultaneously.

[0027] This acknowledges that firmware and software can be valuable, separately tradable commodities. Software is intended to include software that runs on or controls "dumb" or standard hardware to perform desired functions. Software is also intended to include software such as HDL (Hardware Description Language) software that "describes" or defines the configuration of hardware, such as for designing a silicon chip or configuring a general-purpose programmable chip to perform desired functions.

[0028] The embodiments described hereinafter are not limited to implementations that solve some or all of the disadvantages of known pesticide spraying control methods.

[0029] As will be apparent to those skilled in the art, the preferred features can be combined as needed and can also be combined with any of the aspects of the present invention.

[0030] An embodiment of the present invention will be described as an example while referring to the following drawings.

Brief Explanation of Drawings

[0031] [Figure 1] It is a schematic diagram of an example of a first spot spray system. [Figure 2] It is a schematic diagram of an example of a second spot spray system. [Figure 3] It is a schematic diagram of a dual spray bar arrangement. [Figure 4] It is a diagram showing examples of two different one-dimensional (1D) spot dosage profiles. [Figure 5] It is a diagram showing an example of the shape of spot spray. [Figure 6] It is a diagram showing an example of an expression representing the 2D liquid spatial distribution of a nozzle in the form of a lookup table. [Figure 7] It is a diagram showing a first example of an operation method of the spot spray control system shown in FIG. 1 or FIG. 2. [Figure 8] It is a diagram showing two examples of the 2D liquid spatial distribution of spot spray obtained as a result of different opening periods and forward movement. [Figure 9] It is a graphical representation showing how the adjustment of an offset can be used to optimize the received dosage across an object. [Figure 10] It is a diagram showing an example of the method of FIG. 7. [Figure 11] It is a diagram showing an example of a method for adjusting the minimum dosage. [Figure 12] It is a diagram showing a second example of an operation method of the spot spray control system shown in FIG. 1 or FIG. 2. [Figure 13] It is a diagram showing an example of the method of FIG. 12. [Figure 14] It is a diagram showing an example of the method of FIG. 12. [Figure 15] It is a diagram showing an example of the method of FIG. 12. [Figure 16] It is a diagram showing an example of the method of FIG. 12. [Figure 17]This figure shows an example of a third operating method for the spot spray control system shown in Figure 1 or Figure 2. [Figure 18] This figure shows various components of an example of a computer-based spot spray control system. [Modes for carrying out the invention]

[0032] Throughout the entire diagram, a common reference number is used to illustrate similar features.

[0033] The following describes embodiments of the present invention as merely examples. These examples represent the best methods currently known to the applicant for carrying out the present invention, but are not the only ways in which the present invention can be achieved. This specification describes the function of such examples and the steps for constructing and operating such examples. However, the same or equivalent functions and sequences can also be achieved by different examples.

[0034] As mentioned above, spot spraying of pesticides is significantly more efficient than continuous spraying. However, for spot spraying to be effective, an efficient control system is required that can translate the target spraying area into a set of control signals for the valve associated with the nozzle. Errors in this translation can lead to a discrepancy between the target spraying area and the actual spraying area, which can reduce efficiency (for example, if the actual spraying area is larger than the target spraying area) and effectiveness (for example, if parts of the target spraying area are not sprayed). In many applications, the target spraying area is determined in real time (for example, using a camera system that scans the area before the spray bar passes over the entire field area), and therefore the time available to perform the translation is very short (e.g., less than 500ms).

[0035] A crucial spraying parameter when applying pesticides is the control of the dose per unit area. The highest level of spatial dose homogeneity must be guaranteed. In fact, if the dose is insufficient, the chemical efficiency will decrease and work may be hindered. If it is too high, the dose may exceed legal limits, harm the environment, and / or damage crops through plant toxicity.

[0036] Known control methods for pesticide spraying systems rely on each nozzle performing uniform spraying within its own spray pattern shape. When continuous spraying is performed using an array of nozzles mounted perpendicular to the displacement direction of the pesticide sprayer, there is no need to avoid parts of the ground. Therefore, good dose uniformity can be achieved by using nozzles that are separated laterally at a distance shorter than the vertical distance to the target, with a uniform lateral distribution profile, a relatively large lateral jet divergence angle (typical values ​​are 80 to 110 degrees), and where the droplet jets produced by adjacent nozzles overlap widely and combine upon impact with the ground to form uniformly dispersed, dense, cloud-like droplets.

[0037] In spot spraying, achieving uniform droplet distribution is far more difficult for the following reasons: Firstly, the area of ​​each spot spray must be as small as possible and spatially selective as possible (for example, to ensure that the pesticide is sprayed only where needed and not on other nearby plants). This requires the nozzle jet divergence angle to be much smaller than in continuous spraying (typically 15-25 degrees), which does not help to equalize the dose over a wide area. Secondly, the distance from the nozzle to the target must be as short as possible to ensure the best spot placement accuracy. Therefore, overlapping adjacent jets when both the distance from the nozzle to the target and the jet divergence angle are small is a difficult task because the resulting lateral distance between nozzles becomes very short. With such high-density nozzles, it is necessary to use low-flow nozzles to avoid over-spraying of the product. Low-flow nozzles are difficult to manufacture and tend to clog easily. Thirdly, because the sprayer may move at high speeds (e.g., several meters per second), the opening period of the electromechanical valve associated with the nozzle must be very short to produce short spots in the forward direction. This presents a challenge in valve design. Fourthly, the distance from the nozzle to the target may fluctuate during spraying due to the movement of the spray bar from the ground, the irregular surface of the ground, or differences in height between the targets to be sprayed (e.g., when the height of the plants changes). When the distance from the nozzle to the target fluctuates in this way, it becomes difficult to control the overlap ratio of adjacent jets. If the overlap ratio is not well controlled, for example, as the vertical distance increases, this overlap abruptly changes from the overlap of two jets to the overlap of three jets, making it difficult to achieve uniformity through overlap based on the lateral dose profile of a particular nozzle.

[0038] All of these factors make uniform dose distribution based on spot spraying difficult, whether in the case of a single spot spray (i.e., spot spraying when one nozzle is activated) or in the case of larger-scale spot spraying where multiple adjacent nozzles are activated cumulatively. Nevertheless, dose control remains a major challenge in spot spraying systems. Therefore, there is a strong need to develop methods to enable dose control in spot spraying systems characterized by dense nozzle arrays with small jet divergence angles and short distances from nozzle to target (typically 20-30 cm).

[0039] This specification describes an improved method for controlling spot spraying of pesticides that takes into account the heterogeneity of the two-dimensional (2D) liquid spatial distribution of a nozzle. This 2D heterogeneous liquid spatial distribution is used in a control algorithm to define spray zones based on detected objects (e.g., plants), calculate the resulting dose map, and refine the spray zones based on predetermined target dose parameters such as minimum, maximum, or average required doses. Based on these refined spray zones, control signals are generated for an array of nozzles in a spray assembly and output to the spray assembly.

[0040] The pesticides sprayed using the methods described herein may have either the purpose of plant protection or plant fertilization, and the plants that are the detected object, or, if the object is a group of plants, the plants that can form part of the detected object, may be crops or weeds.

[0041] The method described herein enhances the efficiency and adaptability of spot spraying. By precisely controlling the amount of pesticide supplied to the target object, the overall amount of pesticide sprayed can be reduced, thereby improving the efficiency and effectiveness of pesticide use, as well as its manufacture and transport, while minimizing its environmental impact. As will be discussed later, this method does not require precise control of spray height (i.e., the distance between the nozzle and the target object) and can adapt in real time (for example, within the time from detection of the target object to the nozzle passing over it) to changes in the spray assembly and changes in the topology of the surface being sprayed.

[0042] Figure 1 is a schematic diagram of a first spot spray system example 100. System 100 includes a spot spray control system 102, a spray assembly 104, an imaging system 106, and a distance detection unit 108. It should be understood that the spot spray system 100 may also include other elements not shown in Figure 1, such as one or more sensors (e.g., accelerometer, GPS receiver, etc.).

[0043] The spray assembly 104 includes a plurality of nozzles 110 mounted on a spray bar 112. The nozzles 110 are mounted along the spray bar 112 at regular intervals s. Each nozzle 110 has an electromechanical valve 114 positioned between the nozzle 110 and the spray bar 112. These electromechanical valves 114 can be quickly and precisely switched on and off to control the fluid flow from each nozzle 110 to generate each spot spray. A spot spray refers to the fluid output from a nozzle 110 during a single valve opening (i.e., from the time the valve is opened until it is closed again). The time the valve 114 is open to generate a single spot spray can be called the spot period or open period t, and may be approximately 3 to 20 ms. The spray bar 112 is in fluid communication with a tank and a pressure system 116 via an optional inlet electromechanical valve 118. The tank and pressure system 116 includes a tank for holding the pesticide to be sprayed and a pressure system for generating and controlling the pressure p that supplies the pesticide from the tank to the spray bar 112 and finally to the nozzle 110. The amount of fluid output in a single spot spray is a function of the opening period, nozzle design (e.g., nozzle diameter), and pressure, and the area covered by a single spot spray (and therefore the dose per unit area) also depends on the distance between the nozzle and the surface (e.g., the ground). An inlet valve 118 can be used to separate the tank and pressure system 116 from the spray bar 112, for example, for maintenance purposes.

[0044] It should be understood that the spray assembly 104 may differ from that shown in Figure 1. For example, the valve 114 may be incorporated into the spray bar 112, there may be multiple spray bars 112, and / or the inlet valve 118 may be omitted.

[0045] The imaging system 106 scans a portion of the field before the spray bar 112 passes over the area to identify the target for spraying. As described above, depending on the type of pesticide to be sprayed, the target can be a desirable plant (i.e., a crop) or an undesirable plant (i.e., a weed). The imaging system 106 may include one or more cameras and / or other sensors and a processing system configured to process the data captured by the cameras and / or other sensors and output data that determines the target to be sprayed.

[0046] The distance detection unit 108 determines the distance between the spray bar 112 and the target object (i.e., the highest part of the plant being sprayed) for one or more points (e.g., each point on the ground). In many applications, the pesticide is sprayed substantially vertically downward by the nozzles 110, and the distance determined by the distance detection unit 108 is the vertical height. In other spray orientations (e.g., spraying onto a substantially vertical surface), the distance detection unit 108 still determines the distance between the spray bar 112 and the target object, but this distance can be, for example, a distance in a vertical plane. Any preferred technique can be used to perform distance detection (e.g., height detection), and in some examples, the distance detection unit 108 may include a 3D depth sensor or a distance range sensor. The distance detection unit 108 can determine a single distance for the entire spray bar (e.g., the minimum distance between the spray bar and the target object below the spray bar), or it can determine finer-grained distance data, for example, for each group of adjacent nozzles, for each nozzle, or even finer-grained distance data.

[0047] The spot spray control system 102 generates control signals for the valve 114 associated with the nozzle 110 in the spray assembly 104 based on inputs received from the imaging system 106 and optionally from the distance detection unit 108. The spot spray control system 102 implements improved methods for controlling the spot spraying of pesticides as described herein, which are described in further detail below.

[0048] Although Figure 1 shows the distance detection unit 108, the imaging system 106, and the spot spray control system 102 as separate elements, it will be understood that some or all of these may share common components (for example, the distance detection unit 108 and the imaging system 106 may share sensors, and some or all of them may share processing power), or that two or more of the distance detection unit 108, the imaging system 106, and the spot spray control system 102 may be combined.

[0049] Figure 2 is a schematic diagram of a second spot spraying system example 200. System 200 includes a spot spraying control system, spray assembly, imaging system, and distance detection unit, similar to that shown in Figure 1, but only some of these elements are visible in Figure 2. Specifically, Figure 2 shows the nozzle 110 and spray bar 112, as well as the camera 202, which is part of the imaging system. The tank and pressure system, the spot spraying control system, and other parts of the imaging system can be located within the main body 204 of the spot spraying system 200. In this example, the spot spraying system 200 is towed behind a vehicle 206 (e.g., a tractor), and the direction of the vehicle's movement when it is moving forward is indicated by arrow 208. As shown in Figure 2, the imaging system scans a portion of the field 210 before (i.e., prior to) the spray bar 112 passes over the area, i.e., the area to be sprayed 212 is located behind the area being scanned 210. Since the distance between the scanned portion of the field 210 and the sprayed area 212 is constant, the time delay between scanning the field and the spray bar passing over the area can be calculated if the forward speed of the vehicle 206 is known. This time delay is taken into account when generating the control signal for the mechanical valve 114 in order to spatially synchronize the spot spray with the target object.

[0050] The spray assemblies shown in systems 100 and 200 in Figures 1 and 2 each include a single spray bar 112, on which nozzles 110 are mounted at regular intervals s. In some example systems, a spray assembly can include multiple spray bars, and the nozzles on different spray bars are offset from each other. In the example shown in Figure 3, nozzles are mounted at regular intervals s on each spray bar 302, 304, but these nozzles are offset between the spray bars, so the effective nozzle spacing for the entire spray assembly is s' = s / 2. The effective nozzle spacing can be further reduced by having two or more spray bars, for example, s / 3 for three spray bars and s / 4 for four spray bars. The spray bars are oriented perpendicular to the direction of movement of the system, and therefore, when there are multiple spray bars in a spray assembly, they are spaced apart from each other in the direction of movement indicated by arrow 308 in Figure 3. The control methods described herein can be used with any arrangement of spray bars and nozzles. Naturally, when valve control signals are directed to multiple bars simultaneously, the control signals for the second or subsequent bars must be delayed according to the forward speed of the bars so that the spray spots of all bars are positioned on the same horizontal line on the ground.

[0051] The static 2D liquid spatial distribution of a nozzle can be mathematically defined in terms of parameters that define one or more equations, such as a Gaussian or normal distribution, corresponding to the 2D distribution. Figure 4 shows two different examples of one-dimensional (1D) spot dose profiles 402 and 404. These 1D profiles 402 and 404 can represent dose profiles cut along lines such as line X-X' or line Y-Y' passing through an elliptical spot spray 502, as shown in Figure 5. In other examples, the static 2D liquid spatial distribution of the nozzle input to the method can be input in the form of a pre-calculated lookup table. For example, the lookup table can subdivide the 2D spatial distribution into a 2D grid of cells, as shown in example 602 in Figure 6, and specify the dose received within each cell. Figure 6 shows an example of a lookup table 602, as well as equivalent 1D distributions 604 and 606 along two vertical lines passing through the center of the spot spray (e.g., along lines equivalent to lines X-X' and Y-Y' shown in Figure 5).

[0052] Figure 7 shows an example of a first operating method for a spot spray control system, such as the spot spray control system 102 shown in Figure 1. As shown in Figure 7, the method includes determining the position of a first spot spray based on the position of the leading edge of an object (block 702), and then determining the initial positions of one or more new adjacent spot sprays relative to the first spot spray, such that the new and existing spot sprays form a continuous spray zone covering at least a portion of the object (block 704). The position of the first spot spray can be determined such that the leading edge of the object receives at least a predetermined minimum dose, which can be fixed or variable and can be received as an input to the method in various examples. As described above, the object is a plant or group of plants to which the spot spray control system should spray pesticide. The leading edge of the object corresponds to the first point of the object entering the scanned area 210 and therefore the first point of the object passing under the spray bar.

[0053] The initial positions of one or more new adjacent spot sprays are determined in terms of initial lateral and longitudinal offsets from the first spot spray. The lateral offset (which can also be called the lateral offset) is along an axis perpendicular to the direction of movement of the system (and therefore parallel to the spray bar), and each lateral offset is a multiple of the nozzle spacing, or (for example, as shown in Figure 3) a multiple of the effective nozzle spacing if the spray system includes multiple spray bars. The longitudinal offset is along a direction parallel to the direction of movement of the system, and each longitudinal offset corresponds to the duration of movement of the spray assembly at a known velocity. The velocity corresponding to the velocity across the surface on which this object is located can be called the displacement velocity or forward velocity to distinguish it from the velocity at which the nozzles are switched on / off by controlling the corresponding electromechanical valves. The lateral offset determines which nozzles on the spray bar are used (and therefore which electromechanical valves are switched on / off), while the longitudinal offset determines the time interval of the spot sprays, and therefore the control signals. The lateral and longitudinal offsets of the first set of one or more new adjacent spot sprays (placed in the first iteration of block 704) are determined with respect to the position of the first spot spray, whereas the lateral and longitudinal offsets of subsequent sets of one or more new adjacent spot sprays (added in subsequent iterations of the method in Figure 7) can be determined with respect to the position of the first spot spray or the immediately preceding adjacent spot spray.

[0054] As described above, the initial lateral and longitudinal offsets are determined (in block 704) such that the first spot spray and one or more new adjacent spot sprays overlap to form a continuous spray zone that covers at least a portion of the object. For small objects, the spray zone formed by the first spot spray and the first pair of one or more new adjacent spot sprays may cover the entire object, but for large objects, the spray zone may not cover the entire object and may therefore only cover a portion of it.

[0055] The method determines the location of the first spot spray (block 702) and the initial placement of one or more new adjacent spot sprays (block 704), then determines (e.g., calculates) a 2D dose map from the combination of the new spot sprays and the existing spot sprays, and uses this dose map to determine whether the location of one or more new adjacent spot sprays should be adjusted (block 707) and whether further new adjacent spot sprays should be added (709). Determining the 2D dose map (block 706) includes calculating the combined dose of the spots.

[0056] The combined spot spray dose is the dose of pesticide obtained from a first spot spray (positioned in block 702) and one or more further spot sprays (initial positioned in block 704). As described above, each individual spot spray (i.e., each of the first spot spray and one or more further spot sprays) is determined by a non-uniform 2D liquid space distribution as shown in Figures 4-6, which depends on the nozzle design assuming the nozzle is static. However, since the spray assembly is moving, the resulting 2D liquid space distribution of any spot spray is a modified version of the static 2D liquid space distribution as a result of the movement during the period when the valve associated with the nozzle is open. As described above, the valve opening period can be in the range of 3-20 ms, and the system speed can be about 2 m / s, so the nozzle moves about 1-4 cm during the valve opening time. Figure 8 shows two examples of 2D liquid space distributions of spot sprays 802 and 804 obtained as a result of different nozzle opening periods for a given forward speed. In the first resulting 2D liquid spatial distribution example 802, the open period is 5 ms, and in the second resulting 2D liquid spatial distribution example 804, the open period is 15 ms. Arrow 806 indicates the direction of movement of the spray assembly, and it can be clearly seen in the second example that both the dose and spread have increased as a result of the longer open period.

[0057] When the spray assembly is moving perpendicular to the spray bar (e.g., forward), the velocity of each nozzle is the same. However, if the movement of the spray assembly involves some rotation (e.g., due to a turn at a corner), the nozzle velocities will differ at different points along the spray bar. As a result, even if the same static 2D liquid spatial distribution is used for each nozzle, the resulting 2D liquid spatial distribution may differ between nozzles.

[0058] Since the spread of the static 2D liquid spatial distribution depends on the translational velocity (e.g., forward velocity) of the spray assembly, in some examples the nozzle opening period can be adjusted to compensate for changes in velocity (determined, for example, from motion data input to the method). However, since changing the opening period modifies the dose, the maximum spray amount for individual spray spots may differ even with this adjustment. This means that the combined dose of the spot spray and its arrangement changes depending on the local nozzle velocity.

[0059] The combined dose corresponds to the sum of the resulting 2D liquid spatial distributions of each spot spray, taking into account the movement of the spraying system. Therefore, calculating the combined dose involves determining the resulting 2D liquid spatial distribution of each spot spray (including considering the characteristics of each nozzle, their speed, and opening periods if they differ), and then summing up the resulting 2D liquid spatial distributions.

[0060] As shown in Figure 7, static 2D liquid spatial distribution of the nozzles, nozzle spacing, and motion data (e.g., determining the forward speed of the spray assembly) can be provided as input to the method. Alternatively, some or all of these can be fixed (e.g., the method can use fixed nozzle spacing and / or static 2D liquid spatial distribution instead of receiving these as input). If all nozzles in the spray assembly are identical or at least of the same design, the same static 2D liquid spatial distribution can be used for all nozzles in the spray assembly. Alternatively, if there are multiple types of nozzles in the spray assembly, the static 2D liquid spatial distribution of the nozzles corresponding to the lateral positions of the spot sprays is used to determine the initial positions of one or more adjacent spot sprays (in block 704) and to calculate the dose map (in block 706). The static 2D liquid spatial distribution may also depend on one or more other parameters, such as the specific pesticide mixture being sprayed, its dilutability, and the pressure in the tank and pressure system. Depending on these parameters, different static 2D liquid spatial distributions can be used (for example, by selecting and inputting them into the method), or (for example, in block 706) these effects can be included in the calculation of the resulting 2D liquid spatial distribution.

[0061] As described above, the static 2D liquid spatial distribution of the nozzle input to the method can be mathematically determined (for example, in terms of a Gaussian or normal distribution) or input in the form of a pre-calculated lookup table. Using a lookup table reduces the complexity of the calculations that determine the combined dose and dose map, and as mentioned above, this can be advantageous because the time available to perform these calculations is very short.

[0062] The method involves calculating a dose map (block 706) and then determining whether the dose sprayed across the entire object meets predetermined criteria (block 707). For example, these predetermined criteria may be that the dose sprayed at each point on the object exceeds a predetermined minimum value, or that the dose sprayed at each point on the object is between a predetermined minimum value and a predetermined maximum value. If the predetermined criteria are not met ("No" in block 707), one or more new spot spray offsets are added across the entire object to optimize the dose (block 708). This optimization may use the same predetermined criteria as in block 707, or it may use further or different criteria. Examples of optimization criteria include one or more of the following: (i) the dose sprayed at each point of the object exceeds a predetermined minimum value; (ii) the dose sprayed at each point of the object is between a predetermined minimum value and a predetermined maximum value; (iii) the area of ​​the object receiving at least a predetermined minimum dose is maximized; (iv) the difference in received doses across the entire object decreases; (v) the received doses across the entire object decrease while ensuring that they exceed a predetermined minimum value at all points on the object; (vi) the dose at any point on the object does not exceed a predetermined maximum dose; and (vii) the overall received dose outside the object decreases. Since the lateral offset is always a multiple of the nozzle spacing or effective nozzle spacing, there are limitations on how the lateral offset can be adjusted, but the adjustment of the longitudinal offset is more flexible.

[0063] The different optimization criteria (i) to (vii) described above offer different advantages. Criteria (i) and (iii) enhance the effectiveness of spraying. Criteria (ii) and (vi) ensure that when applying fertilizers or other pesticides to crops, the levels do not exceed legally permitted levels or pose a concern regarding plant toxicity. Criteria (iv) provides a more uniform dosage. Criteria (v) can reduce the amount of pesticide used while maintaining effectiveness. Criteria (vii) reduces pesticide waste and thus improves the efficiency of spot spraying, mitigating the negative environmental impact of pesticide overuse. Criteria (vii) also reduces the risk of plant toxicity to crops adjacent to the target. Criteria (vii) can be important when the target is a weed and the pesticide is a herbicide that is not highly selective and therefore may affect adjacent crops.

[0064] Figure 9 shows how offset adjustments can be used to optimize the received dose across the entire object. Figure 9 shows three examples 902, 904, and 906 of the same two spot sprays with different spacings (including individual liquid spatial distributions 908, 910), each example showing a predetermined minimum value (indicated as “min efficiency”), a maximum application rate (indicated as “max applied”), and a predetermined maximum value (indicated as “max legal”). Where the two spot sprays overlap, the cumulative doses from the two spot sprays in the overlapping area 912, 914, and 916, and the scope of the object 918 are shown.

[0065] In the first example 902, the initial placement of the first spot spray 908 is shown on the left, and the initial placement of a new adjacent spot spray 910 is shown on the right. The two spot sprays overlap and thus form a continuous spray zone, satisfying the criteria for block 704, but the combined dose 912 does not exceed a predetermined minimum value across the entire object 918. In the second example 904, the offset of the new adjacent spot spray 910 is reduced, and therefore spot sprays 908 and 910 are closer together. In this second example, the combined dose 914 exceeds a predetermined minimum value across the entire object 918. In the third example 906, the offset of the new adjacent spot spray 910 is further reduced, and therefore spot sprays 908 and 910 are closer together than in the second example. In this third example, the combined dose 916 exceeds a predetermined minimum value across the entire object 918. Whether the second or third example is considered optimal depends on the criteria used. In the second example, the maximum spraying rate is low, so the total dose within the target area is lower than in the third example, but the total dose outside the target area is higher than in the third example.

[0066] If the dose meets the specified criteria ("yes" in block 707), the method determines whether the entire object is covered by the spray zone (block 709), and if it is not covered ("no" in block 709), it may repeat to place another set of one or more new adjacent spot sprays (block 704), and the positions of these newly placed spot sprays may be adjusted as described above.

[0067] When the object defined in the input object data is completely covered ("Yes" in block 709), a control signal for the valve associated with the nozzle in the spray assembly is generated (block 710) using the adjusted offset from block 708 and output to the spray assembly. These control signals can be in the form of on / off commands for the valve (e.g., state vectors). These control signals will be understood to take into account the time it takes from when a point on the field is imaged until the spray bar (determined from motion data) passes that point, in order to synchronize the spot spray with the imaged object. This time is a function of the speed of the spray assembly and the distance between the field of view of the imaging system and the spray bar.

[0068] The method shown in Figure 7 enhances the efficiency and adaptability of spot spraying. By more carefully controlling the amount of pesticide supplied to the target object, the overall amount of pesticide sprayed can be reduced, thus improving the efficiency and effectiveness of pesticide use, as well as its manufacture and transport, while minimizing its environmental impact. This method can adapt in real time (for example, within the time from object detection to the nozzle passing over the object) to changes in the spray assembly and the topology of the surface being sprayed, without requiring precise control of the spray height (i.e., the distance between the nozzle and the target object).

[0069] The method in Figure 7 can be explained with reference to the example shown in Figure 10. In Figure 10, the object 1002 is shown in shade, and the trajectories of the three nozzles are shown by straight lines 1004. The position of the first spot spray 1006 is determined based on the position of the leading edge 1007 of the object 1002 (in block 702). Figure 10 also shows an area 1008 within the spot spray 1006 that receives at least a predetermined minimum dose, and the first spot spray 1006 is positioned such that the leading edge 1007 of the object 1002 receives at least a predetermined minimum dose (i.e., the leading edge 1007 is located within area 1008).

[0070] Next, the initial position of a new adjacent spot spray 1010 is determined (in block 704) such that the two spot sprays 1006 and 1010 overlap to form a continuous spray zone that covers a portion of the object 1002. This initial position of the new adjacent spot spray 1010 is determined in terms of offset, and in the illustrated example, the initial lateral offset dx(1) is one nozzle interval.

[0071] (In block 706) a dose map is calculated for the two spot sprays 1002 and 1010, and (in block 707) this dose map is used to determine whether the resulting doses from the two spot sprays meet a predetermined criterion. For example, this criterion could be that the dose sprayed at each point on the object 1002 exceeds a predetermined minimum value. In the example shown in Figure 10, the combination of the initial placement of the first spot spray 1006 and the second spot spray 1010 does not meet this criterion ("No" in block 707), and therefore (in block 708) the placement of the second spot spray 1010 is adjusted. As shown in Figure 10, the lateral offset dx(1), which is constrained to be a multiple of the nozzle spacing, remains unchanged, while the longitudinal offset dy(1) is reduced so that there is a single area 1012 that receives at least the predetermined minimum dose (rather than two separate areas as in the initial placement). (In block 708) By optimizing the offset, the area of ​​the object 1002 that receives at least the predetermined minimum dose is increased.

[0072] Next, the method determines that the placed spot sprays do not yet completely cover the entire object 1002 ("No" in block 709), and (in the second iteration of block 704) sets the initial position of an additional spot spray 1014 such that this new spot spray overlaps with the spray zones of the existing spot sprays 1006 and 1010 to form a continuous spray zone that covers the object 1002. The initial position of this new adjacent spot spray 1014 is determined in terms of offset, and the offset of the second spot spray 1014 can be adjusted (in block 708) in the same way as the first spot spray. The third figure in Figure 10 shows the final position of the newly added second spot spray 1014. The final lateral offset dx(2) is one nozzle spacing, and the final longitudinal offset dy(2) is smaller than the longitudinal spacing dy(1) between the first and second spot sprays. As shown in Figure 10, the combined doses of the three spot sprays 1006, 1010, and 1014 deliver at least a predetermined minimum dose to the entire object 1002 (i.e., the shaded area 1016, which indicates the area receiving at least the predetermined minimum dose, covers the entire object 1002).

[0073] After determining the positions of the three spot sprays, a control signal is generated (in block 710) using the final offset (from motion data input to the method) and the known velocity of the spray assembly. The lateral offset determines which nozzle is used to form the spot spray, and therefore which electromechanical valve receives the corresponding ON and subsequent OFF signals to form a particular spot spray. The longitudinal offset is converted into a temporal offset between the control signals (e.g., the time difference between a pair of ON and OFF control signals for one spot spray and a pair of ON and OFF control signals for the next spot spray). The control signals are output to the spray assembly to control the electromechanical valve associated with the spray nozzle.

[0074] In the example in Figure 10, three spot sprays are required to completely cover the object, and a control signal is generated at this point (in block 710). However, depending on the size of the object, a different number of spot sprays (e.g., two or three or more spot sprays) may be required, and the control signal can only be generated (in block 710) after determining the positions of all the required spot sprays.

[0075] In some examples, the same static 2D liquid spatial distribution can be used regardless of the distance between the spray bar 112 and the object, as determined by the distance detection unit 108. In other examples, the static 2D liquid spatial distribution used in some or all of the steps of the method in Figure 7 depends on the detected distance. For example, the same static 2D liquid spatial distribution can be input to the method along with the detected distance, and the method may further include modifying the input static 2D liquid spatial distribution in a height-dependent manner when calculating the combined dose (similar to modifications performed based on, for example, the forward movement of the spray assembly). In other examples, different static 2D liquid spatial distributions can be stored and used when the distance between the spray nozzle and the object is different. A longer distance results in a larger (i.e., expanded) spot spray, but the dose per unit area decreases because the spray volume remains the same but spreads over a wider area. In some examples, a single detected distance provided by the distance detection unit 108 (e.g., a single distance between the spray bar and the object) can be used for all nozzles, but in other examples, more granular distance data, such as distance data per nozzle, can be provided. As a result, even if the same static 2D liquid spatial distribution is used for each nozzle and all nozzles are moving at the same speed, the resulting 2D liquid spatial distribution may differ from nozzle to nozzle (for example, if the underlying surface is not flat and / or if the height of the object is different).

[0076] As described above, the nozzle opening period affects the spread of the 2D liquid spatial distribution as the spray assembly moves. The method described above assumes that the opening period is constant and the same for all nozzles and all spot sprays. In a variation of the method described above, the spray control system can control the nozzle opening period to maintain a constant resulting 2D liquid spatial distribution in response to variations in the forward velocity of the nozzles. For example, variations in forward velocity may be the result of rotation of the spray assembly and / or changes in the forward velocity of the spray assembly.

[0077] Instead of changing the opening period to maintain a constant 2D liquid spatial distribution in response to variations in forward velocity, the nozzle opening period can also be changed, along with the offset (of block 708), to further optimize the received dose, for example, by maintaining the dose at all points within a predetermined minimum and maximum dose, and / or by suppressing the overall dose while ensuring that all points of the object receive at least a predetermined minimum dose.

[0078] As described above, the predetermined minimum dose used can be fixed or variable and can be provided as input to the method (for example, as shown in Figure 7). In some examples, the spot spray control system 102 can determine the predetermined minimum dose used by the method in Figure 7 based on data received from the imaging system 106. Alternatively, the imaging system 106 can perform this determination and input the result to the spot spray control system 102. Object data is received as shown in Figure 11 (block 1102). If the method is performed by the spot spray control system 102, this data is received from the imaging system 106. Based on the received data, the predetermined minimum dose can be adjusted based on the size and / or type of the object, or selected from a plurality of predetermined minimum dose candidates (block 1104). The resulting minimum dose is then output for use in the method described above (for example, the method shown in Figure 7) (block 1106).

[0079] For larger objects (in block 1104), the minimum dose can be increased, where the size of the object can mean its area and / or its height (i.e., how tall it is). In addition to or instead of this, the minimum dose may also depend on the type of plant that is the object.

[0080] By adjusting the minimum dose based on size and / or type, the dose sprayed onto the target can be tailored to the specific target being sprayed, thereby increasing the overall effectiveness and / or efficiency of pesticide application. This adjustment can also reduce the dose reaching adjacent crops, thus lowering the phytotoxicity of those plants if the pesticide being sprayed is a herbicide.

[0081] While the method in Figure 11 refers to the modification of a predetermined minimum dose, a similar method can be used to determine or modify a predetermined maximum dose when using a predetermined maximum dose as one of the criteria in Block 707 and / or Block 708.

[0082] In the method described above, the adjusted offset used to generate the control signal (in block 710) after being determined (in block 708) is determined based on a dose map (calculated in block 708), rather than being determined according to any pattern. Figure 12 shows an example of a second operating method of a spot spray control system, such as the spot spray control system 102 shown in Figure 1, which uses a repeating pattern for an object that cannot be covered by four adjacent spot sprays. The method shown in Figure 12 is a variation of the method shown and described above in Figure 7. The method in Figure 12 can be used for objects of any size (including, for example, those smaller than the spray zone of four spot sprays), but is particularly suitable for large objects (for example, those requiring five or more, up to tens or hundreds of spot sprays, to cover).

[0083] As shown in Figure 12, the method begins in the same way as in Figure 7, but after determining the position of the first spot (block 702), the initial positions of three new adjacent spot sprays are determined (block 1204). As will be described later, the line connecting the center of the first spot spray and the centers of the three new spot sprays forms a quadrilateral (e.g., a square, rectangle, or rhombus).

[0084] The method continues as in Figure 7, and if the dose from the initial placement of the four spots (the first spot and three additional spots) does not meet a predetermined criterion (block 707, "No"), the offset of the three additional spots is adjusted so that the dose received within the quadrilateral defined by the center points of the four spots is optimized (block 1208). The predetermined criterion used in block 707 may be the same as described above with reference to Figure 7, or it may be modified to relate to a quadrilateral rather than an object, for example, so that the dose distributed at each point on the quadrilateral exceeds a predetermined minimum value, or so that the dose distributed at each point on the quadrilateral is between a predetermined minimum value and a predetermined maximum value. Examples of optimization criteria that can be used in block 1208 include one or more of the following: (i) the dose distributed at each point within the quadrilateral is greater than a predetermined minimum; (ii) the dose distributed at each point within the quadrilateral is between a predetermined minimum and a predetermined maximum; (iii) the difference in received dose across the entire quadrilateral decreases; (iv) the received dose across the entire quadrilateral decreases while ensuring that it is greater than a predetermined minimum at all points on the quadrilateral; and (v) the dose at any point on the quadrilateral does not exceed a predetermined maximum dose. As before, the lateral offset is always a multiple of the nozzle spacing or effective nozzle spacing, and therefore there are limitations on how the lateral offset can be adjusted, but the adjustment of the longitudinal offset is more flexible.

[0085] When the dose from the initial placement of the four spots (the first spot and three additional spots) meets a predetermined criterion ("yes" in block 707), it is determined whether the object is completely covered (block 709). If it is not completely covered, additional spot sprays are placed at the same offset as the first three new adjacent spot sprays to further cover the object (block 1212).

[0086] If the object does not extend longitudinally beyond the threshold distance, a control signal can be generated (in block 710) when the entire object is covered (i.e., when additional spots placed in block 1212 cover the entire object before proceeding to block 710). If the object does extend longitudinally beyond the threshold distance, a control signal can be generated (in block 710) to form the spot sprays already placed (in blocks 702, 1204, and 1212) before the entire object is covered (as shown by the dotted line from block 710 to block 709). In such an example, the additional spot sprays placed in block 1212 cover only a portion of the object, not the entire object, and a control signal is generated (in block 710) for these already placed spot sprays (from blocks 702, 1204, and 1212) before placing additional spot sprays (in block 1212) to extend the coverage of the object. The method can involve repeating a loop including blocks 709, 1212, and 710 until the object is completely covered ("yes" in block 709) and control signals for all spot spraying are generated (in block 710). The threshold distance can be determined based on the longitudinal field of view of the imaging system 102. For example, the threshold distance can be set to be equal to the longitudinal range of the portion of the field 210 that the imaging system 202 can image (as shown in Figure 2).

[0087] As described above, when generating control signals (in block 710) based on the known velocity of the spray assembly (received in the motion data input to the method), the longitudinal interval of the spot spray is converted into a temporal interval. The lateral offset determines which electromechanical valve receives the on and off control signal pair to form the spot spray, and the open period corresponds to the interval between the on and off control signals in the on and off control signal pair.

[0088] The method in Figure 12 can be further explained with reference to the examples shown in Figures 13 and 14. In the example shown in Figure 13, the four spots initially placed (in blocks 702 and 1204) are indicated by "1", and the quadrilateral 1302 formed by the lines connecting the centers of these spots is also shown. In this example, the lateral spacing dx is equal to the nozzle spacing, and as a result the quadrilateral is either a rectangle or a square. When adjusting the offset (in block 1208) to optimize the receiving dose within the quadrilateral 1302 (for example, so that all points within the quadrilateral 1302 are sure to fall between a predetermined minimum and maximum value), the only direction that is actually free is the longitudinal direction (i.e., adjusting dy), since the lateral spacing is constrained to be a multiple of the nozzle spacing. After adjusting the offset, the resulting offsets dx and dy are used to arrange further spot sprays (indicated by "2") (in block 1212) so that the entire object 1304 receives at least a predetermined minimum dose.

[0089] In the example shown in Figure 14, the first four spots (in blocks 702 and 1204) are indicated by "1," and the quadrilateral 1402 formed by the lines connecting the centers of these spots is also shown. In this example, the lateral spacing dx is equal to twice the nozzle spacing, resulting in a rhombus-shaped quadrilateral. When adjusting the offset (in block 1208) to optimize the received dose within quadrilateral 1402 (for example, so that all points in quadrilateral 1302 are reliably between a predetermined minimum and maximum value), the only direction that is actually free is the longitudinal direction (i.e., adjusting dy), since the lateral spacing is constrained to be a multiple of the nozzle spacing. As shown in Figure 14, two longitudinal offsets dy are involved in the initial four spot sprays, but these offsets are the same and remain the same when the adjustment is performed (in block 1208). After adjusting the offsets, the resulting offsets dx and dy are used to position further spot sprays (indicated as "2") so that the entire object 1404 (in block 1212) receives at least a predetermined minimum dose.

[0090] As shown in Figures 12 to 14, using iterative patterns on larger objects reduces the computational cost when calculating the control signal, which is advantageous because, as mentioned above, the time available to generate the control signal is very limited.

[0091] Figures 15 and 16 show two variations of the arrangement shown in Figure 14. In Figures 15 and 16, the spot sprays are arranged using the method of Figure 12, but the rows of spot sprays are not aligned perpendicular to the forward direction, but are slightly angled from the perpendicular. This means that nozzle opening occurs at different times (i.e., because the nozzles are not aligned in the forward direction), and as a result, less pressure adjustment is required within the spray system. In the example shown in Figure 15, each individual spot spray has a nozzle orientation such that its minor axis is aligned in the forward direction, resulting in an asymmetric spot spray pattern. In contrast, in the example shown in Figure 16, the orientation of the spot sprays is also tilted by the same angle (e.g., rotated by about 10° along the vertical axis) so that the major axes of the spot sprays in the rows are aligned. As a result, the spot spray pattern is symmetrical.

[0092] In a variation of the method described above, in addition to adjusting the offset (in blocks 708 and 1208), the nozzle opening period can be adjusted (for example, to satisfy one or more of the criteria (i) to (vii) described above with reference to Figure 7, or one or more of the criteria (i) to (v) described above with reference to Figure 12). As described above with reference to Figure 8, adjusting the valve, and therefore the nozzle, opening period changes the static 2D liquid spatial distribution, which in turn increases both the dose and longitudinal spread when calculating the resulting 2D liquid spatial distribution (including the effect of the movement of the spray assembly).

[0093] In a further variation of the method described above, in addition to adjusting the offset (in blocks 708 and 1208) and in addition to or instead of adjusting the opening period, the distance between the nozzle and the object can be adjusted (for example, to satisfy one or more of the criteria (i) to (vii) described above with reference to Figure 7, or one or more of the criteria (i) to (v) described above with reference to Figure 12). Adjusting the distance between the nozzle and the object changes the static 2D liquid spatial distribution (because the spread in both the longitudinal and lateral directions increases).

[0094] In the method described above, the offset is determined and adjusted dynamically during the spraying operation (i.e., while the imaging system is scanning the field). Figure 17 shows an example of a third operating method for a spot spray control system, such as the spot spray control system 102 shown in Figure 1. This method uses a repeating pattern on the object (similar to the method in Figure 12), but the offset used is selected from a set of pre-calculated tables. These tables are generated before the spraying operation and can be used for many spraying operations. Memory is required to store these tables, and this memory may reside away from the spot spray control system 102 (for example, it may be stored in a remote data center). However, by using pre-calculated tables, calculations required during the spraying operation are eliminated, allowing for faster placement of spot sprays. The method shown in Figure 17 is a modification of the method shown and described in Figures 7 and 12. The method in Figure 17 can be used for objects of any size.

[0095] As shown in Figure 17, this precalculation determines a table of longitudinal offsets for the first spot spray and lateral and longitudinal offsets for new adjacent spot sprays, along with the opening period for each spot spray, for different values ​​of one or more parameters from among the parameters of speed, dose requirements (e.g., minimum and / or maximum doses), pressure, and distance between the nozzle and the object (block 1702). Within each set of precalculated values, which includes (i) the longitudinal offset for the first spot spray, (iii) the lateral and longitudinal offsets for one or more new adjacent spot sprays, and (iii) the nozzle opening period for each spot spray, the nozzle opening period may be the same for each spot spray or may differ between spot sprays (e.g., so that different opening periods are determined for each spot spray). This precalculation (in block 1702) can be said to be performed offline, as the data is used for subsequent spray operations after it has been performed before the spraying operation. As shown in Figure 17, the pre-calculation can take as input the static 2D liquid spatial distribution of a nozzle, which can be defined in terms of a lookup table, as described above. In some examples, different tables (or different sets of tables) can be pre-calculated for different nozzles having different static 2D liquid spatial distributions.

[0096] During spraying, a pre-calculated table is used to determine the offset for the first spot spray and one or more new adjacent spot sprays, as well as the corresponding nozzle open duration for each spot spray (block 1704). This determination involves looking up the offset and nozzle duration in multiple pre-calculated tables corresponding to the current velocity (as shown in the motion data), a predetermined minimum dose, pressure, and distance, and optionally the nozzle type (the pre-calculated tables include different tables for different nozzles).

[0097] Once the offset is obtained (block 1704), the positions of the first spot spray and the new adjacent spot spray are determined (block 1706). The lateral position of the first spot spray is determined in the same manner as described above (block 702), and its longitudinal position is set at a point offset forward from the leading edge of the object by the longitudinal offset determined in the pre-calculated table. The positions of the new adjacent spot spray are determined relative to the first spot spray (in block 1204) using the lateral and longitudinal offsets as described above.

[0098] The method then continues as in the method shown in Figure 12. Once the positions of the first spot spray and one or more adjacent spot sprays are determined (in block 1706), it is determined whether the object is completely covered (block 709). If it is not completely covered, additional spot sprays are placed at the same offset as one or more new adjacent spot sprays to further cover the object (block 1212).

[0099] If the object does not extend longitudinally beyond a threshold distance, a control signal can be generated (in block 710) when the entire object is covered (i.e., when additional spots placed in block 1212 cover the entire object before proceeding to block 710). If the object does extend longitudinally beyond a threshold distance, a control signal can be generated (in block 710) to form the spot sprays already placed (in blocks 1706 and 1212) before the entire object is covered (as shown by the dotted line from block 710 to block 709). In such an example, the additional spot sprays placed in block 1212 cover only a portion of the object, not the entire object, and a control signal is generated (in block 710) for these already placed spot sprays (from blocks 1706 and 1212) before placing additional spot sprays (in block 1212) to extend the coverage of the object. The method can involve repeating a loop including blocks 709, 1212, and 710 until the object is completely covered ("yes" in block 709) and control signals for all spot spraying are generated (in block 710). The threshold distance can be determined based on the longitudinal field of view of the imaging system 102. For example, the threshold distance can be set to be equal to the longitudinal range of the portion of the field 210 that the imaging system 202 can image (as shown in Figure 2).

[0100] As described above, when generating control signals (in block 710) based on the known velocity of the spray assembly (received in the motion data input to the method), the longitudinal interval of the spot spray is converted into a temporal interval. The lateral offset determines which electromechanical valve receives the on and off control signal pair to form the spot spray, and the open period (determined in block 1704) corresponds to the temporal interval between the on and off control signals in the on and off control signal pair.

[0101] The method in Figure 17, in terms of spot spray placement, results in the same generated control signals as the method in Figure 12, but instead of adjusting the offset during the spraying process, the data is pre-calculated and retrieved based on the actual dynamic variables of the spraying process (e.g., motion data, a predetermined minimum dose, distance, etc.).

[0102] In the methods described above, many of the criteria ensure that all parts of the object receive at least a predetermined minimum dose. In variations of the methods described above, the criteria can be modified so that at least a minimum percentage of the object (e.g., at least 90% of the object) receives a predetermined minimum dose. When both a predetermined minimum and a predetermined maximum value are used, the predetermined maximum value must not be exceeded at any point in the spraying zone, even if a small portion of the object receives a dose lower than the predetermined minimum value.

[0103] The method described above can be implemented by a spot spray control system, such as the spot spray control system 102 shown in Figure 1. The spot spray control system can be implemented by one or more processors. The one or more processors can be programmable (e.g., a central processing unit (CPU) or microcontroller), a field-programmable gate array (FPGA), a DSP, an ASIC, a PLC, and / or one or more ARM processors. Figure 18 shows various components of an example spot spray control system in the form of a computer-based device 1800. As described above, this computer-based device can also perform some of the functions of the distance detection unit 108 and imaging system 106 shown in Figure 1.

[0104] The computer-based device 1800 includes one or more processors 1802, which may be a microprocessor, controller, or any other preferred type of processor, that process computer-executable instructions that control the operation of the device to perform the methods described herein (for example, as shown in Figures 7, 12, and 17). In some examples, for example when using a system-on-chip architecture, the processors 1802 may include one or more fixed function blocks (also called accelerators) that implement in hardware (rather than in software or firmware) a portion of the method of controlling the spot spraying system. The computer-based device may be provided with platform software, including an operating system 1804 or any other preferred platform software, so that application software 1806, such as software that performs the methods described herein, can be run on the device.

[0105] Computer-executable instructions may be provided using any computer-readable medium accessible to the computer-based device 1800. Computer-readable mediums may include computer storage media, such as memory 1808, and communication media. Computer storage media, such as memory 1808, include volatile and non-volatile, removable and non-removable media implemented by any method or technique for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, RAM, ROM, EPROM, EEPROM, flash memory, or other memory technologies; CD-ROM, digital versatile disk (DVD), or other optical storage devices; magnetic cassettes, magnetic tapes, magnetic disk storage, or other magnetic storage devices; or any other non-transmission media that can be used to store information accessible to the computer device. In contrast, communication media can embody computer-readable instructions, data structures, program modules, or other data in the form of modulated data signals, such as carrier waves, or other transport mechanisms. As defined herein, computer storage media are not included in communication media. Although the computer-based device 1800 contains computer storage media (memory 1808), it will be understood that the storage can be distributed or located in separate locations and accessed via a network or other communication link (for example, using a communication interface 1810).

[0106] The communication interface 1810 can be configured to receive data used in the manner described herein, such as motion data (e.g., from the vehicle 206 shown in Figure 2, or from sensors in the spot spray system), object data (e.g., from the imaging system 106), and height data (e.g., from the distance detection unit 108). The communication interface 1810 can also be configured to output generated control signals (e.g., to the electromechanical valve 114 in the spray assembly 104).

[0107] The computer-based device 1800 may also include an input / output interface 1812 configured to output display information to a display device 1814, which may be separate from or integrated with the computer-based device 1800. For example, the display device 1814 may be mounted on the main body 204 of the spot spraying system 200 shown in Figure 2, or located within the vehicle 206. In addition to or instead of this, the display information may also be output to a remote display device 1814 (at a monitoring position away from the spot spraying system) via a communication interface 1810. The display information can provide a graphical user interface. The input / output interface 1812 may also be configured to receive and process input from one or more devices, such as a user input device 1816 (for example, one or more buttons on the main body 204 of the spot spraying system 200 shown in Figure 2, or located in the vehicle 206). This user input can be used to adjust parameters of the method or to provide input such as a predetermined minimum dose. In some embodiments, if the display device 1814 is a touch-sensor display device, the display device 1814 may also function as a user input device 1816. In some examples, the input / output interface 1812 can be configured to output the generated control signals (for example, to the electromechanical valve 114 in the spray assembly 104) in place of or in addition to the communication interface 1810.

[0108] Memory 1808 can be configured to store data used in the methods described herein, such as static 2D liquid spatial distribution data 1818 and spray assembly configuration data 1820 (e.g., nozzle spacing). When using the method shown in Figure 17, memory 1808 can be configured to store a pre-calculated table.

[0109] Figure 18 shows a single computer device that can be locally implemented within the spot spraying systems 100, 200 shown in Figures 1 and 2. In other examples, some of the processing and / or data storage can be implemented in a location away from the spraying assembly, such as on a remote computer device located in a data center or elsewhere. For example, the configuration data for the static 2D liquid spatial distribution 1818 and / or spraying assembly 1820 can be stored remotely and accessed via the communication interface 1810. In addition to or instead of this, the remote computer device can perform the calculation of the dose map (in block 706) and the correction of the offset (in blocks 708 and 1208), and the resulting corrected offset can be received by the spraying system via the communication interface 1810. In other examples, processing and / or data storage can be divided in different ways between a local computer device close to the spraying assembly and a remote computer device (or between multiple local computer devices if, for example, data processing is performed on a computer device different from the data storage).

[0110] As used herein, the term “computer” means any device having processing power capable of executing instructions. Those skilled in the art will recognize that such processing power is incorporated into many different devices, and therefore the term “computer” includes PCs, servers, mobile phones, personal digital assistants, and many other devices.

[0111] A person skilled in the art would recognize that the memory used to store program instructions can be distributed across an entire network. For example, a remote computer can store an example of the process described as software. A local computer or terminal computer can access the remote computer, download part or all of the software, and execute the program. Alternatively, the local computer can download part of the software as needed, or execute some of the software instructions on the local terminal and the rest on the remote computer (or computer network). A person skilled in the art would also recognize that, by utilizing prior art known to those skilled in the art, all or part of the software instructions can be executed by dedicated circuits such as DSPs or programmable logic arrays.

[0112] As will be apparent to those skilled in the art, any range or apparatus value shown herein can be extended or modified without loss of the intended effect.

[0113] It will be understood that the benefits and advantages described above may relate to one embodiment or to multiple embodiments. The embodiments are not limited to those that solve some or all of the problems mentioned or that have some or all of the benefits and advantages described.

[0114] A reference to an item “a certain” means one or more of these items. The term “comprising” as used herein means including an identified method block or element, but such block or element does not include an exclusive list, and the method or apparatus may include further blocks or elements.

[0115] The steps of the methods described herein can be performed in any preferred order, or simultaneously as necessary. Individual blocks can also be removed from any of the methods without departing from the spirit and scope of the subject matter described herein. Aspects of any of the embodiments described above can also be combined with aspects of any other embodiments described above to form further embodiments without losing the effect of exploration.

[0116] The above description of preferred embodiments is merely illustrative and will be understood to be capable of various modifications by those skilled in the art. While various embodiments have been described above with a certain degree of detail or by reference to one or more individual embodiments, those skilled in the art will be able to make numerous changes to the disclosed embodiments without departing from the spirit or scope of the invention. [Explanation of symbols]

[0117] 1002 Object 1004 The Trajectory of Three Nozzles 1006 First spot spray 1007 Front edge of the object 1008 Area receiving the specified minimum dose 1010 Second spot spray 1014 Further spot spraying 1016 Area receiving the specified minimum dose dx(1) Initial lateral offset dy(1) Initial longitudinal offset dx(2) Final lateral offset dy(2) Final longitudinal offset

Claims

1. A method for operating a spot spray control system that sprays pesticides using a spray assembly including an array of nozzles, (i) Determining the position of the first spot spray based on the position of the leading edge of the object (702), (ii) With respect to the lateral and longitudinal offsets of the first spot spray, the initial position of at least one new adjacent spot spray (704, 1204) is determined such that the combined dose of the first and new spot sprays forms a continuous spray zone covering a portion of the object, wherein each of the first and new spot sprays is determined by a non-uniform two-dimensional liquid spatial distribution, and the lateral offset is a multiple of the effective spacing between the nozzles in the nozzle array. (iii) Determining a two-dimensional dose map obtained from the first and new spot sprays (706), (iv) In response to determining from the two-dimensional dose map that a predetermined dose criterion is not met (707), adjust the offset of the at least one new adjacent spot spray to optimize the received dose (708, 1208), (v) Generating a control signal for the nozzle array according to the position of the first spot spray and the adjusted offset of the at least one new adjacent spot spray (710), (vi) Outputting the control signal to the spray assembly, A method that includes this.

2. In response to determining from the two-dimensional dose map that the object is not completely covered by the spray zone (709), the steps (ii) to (iv) are further repeated until the object is completely covered. The method according to claim 1.

3. Determining the initial position of at least one new adjacent spot spray with respect to the first spot spray in terms of lateral and longitudinal offsets includes determining the initial position of three new adjacent spot sprays with respect to the first spot spray (1204), Adjusting the offset of at least one new adjacent spot spray to optimize the received dose includes adjusting the offset of the three new adjacent spot sprays to optimize the received dose within the quadrilateral defined by the first spot spray and the three new adjacent spot sprays (1208), The method according to claim 1.

4. In response to determining from the two-dimensional dose map that the object is not completely covered by the spray zone (709), the further includes arranging additional spot sprays using the adjusted offset until the object is completely covered (1212), The method according to claim 3.

5. The two-dimensional liquid spatial distribution of the spot spray is determined based on the static two-dimensional liquid spatial distribution of the nozzle and the motion data received from the spray assembly. The method according to any one of claims 1 to 4.

6. The two-dimensional liquid spatial distribution of the spot spray is determined based on the static two-dimensional liquid spatial distribution of the nozzle and the detected distance between the nozzle array and the target object. The method according to any one of claims 1 to 5.

7. The two-dimensional liquid spatial distribution of the spot spray is determined based on the static two-dimensional liquid spatial distribution of the nozzle and the nozzle's open period. The method according to any one of claims 1 to 6.

8. The two-dimensional liquid spatial distribution of the spot spray is determined in a lookup table. The method according to any one of claims 5 to 7.

9. The two-dimensional liquid spatial distribution of the spot spray is determined using a Gaussian distribution or a normal distribution. The method according to any one of claims 5 to 7.

10. The further includes adjusting the nozzle opening period in response to changes in the forward speed of the nozzle during spraying, so as to maintain a constant two-dimensional liquid spatial distribution of the spot spray. The method according to any one of claims 1 to 9.

11. Optimizing the received dose includes ensuring that the received dose reliably exceeds a predetermined minimum dose. The method according to any one of claims 1 to 10.

12. (1104) further includes adjusting the predetermined minimum dose based on the size or type of the object, The method according to claim 11.

13. Optimizing the received dose includes ensuring that the received dose does not exceed a predetermined maximum dose. The method according to any one of claims 1 to 12.

14. The instructions, when executed by a computer, include instructions that cause the computer to perform the method according to any one of claims 1 to 13. Computer program.

15. A computer program according to claim 14 is stored in Computer-readable media.

16. A spot spray control system for spraying pesticides using a spray assembly including an array of nozzles, Processor (1802), One or more interfaces (1810, 1812) configured to receive object data and output control signals to the spray assembly, Memory (1808) configured to store computer programs, The computer program, when executed by the processor, (i) Determining the position of the first spot spray based on the position of the leading edge of the object (702), (ii) With respect to the lateral and longitudinal offsets of the first spot spray, the initial position of at least one new adjacent spot spray (704, 1204) is determined such that the combined dose of the first and new spot sprays forms a continuous spray zone covering a portion of the object, wherein each of the first and new spot sprays is determined by a non-uniform two-dimensional liquid spatial distribution, and the lateral offset is a multiple of the effective spacing between the nozzles in the nozzle array. (iii) Determining a two-dimensional dose map obtained from the first and new spot sprays (706), (iv) In response to determining from the two-dimensional dose map that a predetermined dose criterion is not met (707), adjust the offset of the at least one new adjacent spot spray to optimize the received dose (708, 1208), (v) Generating a control signal for the nozzle array according to the position of the first spot spray and the adjusted offset of the at least one new adjacent spot spray (710), (vi) Outputting the control signal to the spray assembly via the one or more interfaces, A spot spray control system that causes the spot spray control system to perform the above-mentioned spot spray control system.

17. A method for operating a spot spray control system that sprays pesticides using a spray assembly including an array of nozzles, Using a pre-calculated table, determine the longitudinal offset of the first spot spray, the lateral and longitudinal offsets of one or more new adjacent spot sprays, and the nozzle opening period for each spot spray (1704), wherein each of the first and new spot sprays is determined by a non-uniform two-dimensional liquid space distribution, and the lateral offset is a multiple of the effective spacing between nozzles in the nozzle array. The position of the first spot spray is determined based on the position of the leading edge of the object and the determined longitudinal offset of the first spot spray, Based on the determined lateral and longitudinal offsets of the one or more new adjacent spot sprays, the positions of the one or more new adjacent spot sprays relative to the position of the first spot spray are determined (1706), (710) A control signal is generated for the nozzle array according to the position of the first spot spray and the one or more new adjacent spot sprays, the opening period of each spot spray, and the displacement velocity of the nozzle. Outputting the aforementioned control signal to the spray assembly, A method that includes this.

18. Using a pre-calculated table, the longitudinal offset of the first spot spray, the lateral and longitudinal offsets of one or more new adjacent spot sprays, and the nozzle opening period for each spot spray are determined. Based on the speed of the nozzle array, a predetermined minimum dose, and the input distance between the nozzle and the object, a search is performed within the pre-calculated table to determine the longitudinal offset of the first spot spray, the lateral and longitudinal offsets of one or more new adjacent spot sprays, and the nozzle opening period for each spot spray. The method according to claim 17, including the method described in claim 17.

19. In response to determining that the object is not completely covered by the first and new spot sprays (709), the further includes arranging additional spot sprays using the determined lateral and longitudinal offsets until the object is completely covered (1212), The method according to claim 17 or 18.

20. The method further includes pre-calculating the table of offsets and nozzle open periods (1702), the table including the longitudinal offset of a first spot spray for different values ​​of velocity, a given dose, pressure, and distance to the object, the lateral and longitudinal offsets of one or more new adjacent spot sprays, and the nozzle open period for each spot spray. The method according to any one of claims 17 to 19.

21. Includes an instruction that causes the computer to perform the method according to any one of claims 17 to 20 when executed by the computer, Computer program.

22. A computer program according to claim 21 is stored in Computer-readable media.

23. A spot spray control system for spraying pesticides using a spray assembly including an array of nozzles, Processor (1802), One or more interfaces (1810, 1812) configured to receive object data and output control signals to the spray assembly, Memory (1808) configured to store computer programs, The computer program, when executed by the processor, Using a pre-calculated table, determine the longitudinal offset of the first spot spray, the lateral and longitudinal offsets (1704) of one or more new adjacent spot sprays, and the nozzle opening period for each spot spray, wherein each of the first and new spot sprays is determined by a non-uniform two-dimensional liquid space distribution, and the lateral offset is a multiple of the effective spacing between nozzles in the nozzle array. The position of the first spot spray is determined based on the position of the leading edge of the object and the determined longitudinal offset of the first spot spray, Based on the determined lateral and longitudinal offsets of the one or more new adjacent spot sprays, the positions of the one or more new adjacent spot sprays relative to the position of the first spot spray are determined (1706), (710) A control signal is generated for the nozzle array according to the position of the first spot spray and the one or more new adjacent spot sprays, the opening period of each spot spray, and the displacement velocity of the nozzle. Outputting the control signal to the spray assembly via the one or more interfaces described above, A spot spray control system that causes the spot spray control system to perform the above-mentioned spot spray control system.

Images