Device for measuring deposition amount and particle size spectrum of aerial pesticide application fog drops

Abstract

The invention provides a device for measuring deposition rate and particle size spectrum of aerial pesticide application fog drops, which belongs to the technical field of intelligent detection, and comprises the following steps: a fog drop collector receives settled fog drops in the pesticide application process and mixes the fog drops with dielectric carrier liquid to generate an oil-based mixture; the coplanar electrode capacitance sensing module comprises a passivation insulating layer and an electrode cover; the micro-flow control pump is used for controlling the flow speed of the oil-based mixture flowing through the fog drop conveying channel; and the processor determines the deposition amount and the particle size spectrum of the fog drops according to a capacitance signal generated by the coplanar electrode in the process that the oil-based mixture flows through the fog drop conveying channel. The capacitance sensing area is established based on the coplanar electrode, the capacitance signal of the sensing area is changed by utilizing the dielectric constant difference between the dielectric carrier liquid and the liquid drop, the number of the fog drops and the particle size corresponding to each fog drop can be reversely deduced through the capacitance signal, real-time measurement can be realized, the measurement efficiency is improved, and good environmental adaptability is achieved; and an intelligent detection means is provided for aviation pesticide application quality evaluation.

Description

Technical Field

[0001] The present invention relates to the field of intelligent detection technology, and in particular to a device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application. Background Art

[0002] During the spraying process, detecting the amount of spray droplet deposition and particle size spectrum is an important means to evaluate the quality of spraying, and provides important guidance for aircraft spraying spray pressure regulation, nozzle model selection, spraying flow control, flight parameter optimization and the development of precision variable spraying equipment.

[0003] Currently, the droplet deposition and particle size spectrum of sprayed pesticides are primarily measured using the water-sensitive paper method. This method involves placing water-sensitive paper on the ground in the spraying area. When droplets land on the paper, they turn into blue spots. After the experiment, the paper is collected and an image of the droplet deposition is obtained using a microscope or specialized scanning software. Image software is then used to calculate the droplet size.

[0004] The aforementioned water-sensitive paper measurement method has the following drawbacks: It requires sample placement before testing and subsequent collection and return to the laboratory for image acquisition and software measurement. This method cannot achieve real-time measurement of droplet size spectra during field application, and is time-consuming and labor-intensive. For aerial application testing of large spray widths and large operating areas, the collected water-sensitive paper samples typically take two weeks or even longer to process, resulting in high labor intensity, time, and material costs. It should be noted that in humid environments, water-sensitive paper easily becomes damp and turns blue, making it unusable. Furthermore, measurement efficiency is low. Summary of the Invention

[0005] The present invention provides a device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application, which is used to solve the defects of the prior art in droplet deposition detection, such as poor real-time performance, low precision, and time and labor consumption.

[0006] The present invention provides a device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application, which mainly includes: A droplet collector, the droplet collector being used to receive settled droplets during the application process and mix the droplets with a dielectric carrier liquid to form an oil-based mixture; the dielectric carrier liquid is immiscible with the droplets and has different dielectric constants; A coplanar electrode capacitance sensing module, comprising a passivation insulating layer and an electrode cover, wherein the passivation insulating layer and the electrode cover cooperate to form a droplet transport channel that penetrates the coplanar electrode capacitance sensing module, wherein a coplanar electrode composed of at least two electrodes is embedded in the passivation insulating layer; an inlet of the droplet transport channel is connected to an outlet of the droplet collector; a microfluidic control pump, the microfluidic control pump being used to control the flow rate of the oil-based mixture flowing through the droplet transport channel; A processor is used to determine the deposition amount and particle size spectrum of the droplets based on the capacitance signal generated by the coplanar electrode during the process of the oil-based mixture flowing through the droplet transport channel.

[0007] According to the device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application provided by the present invention, the coplanar electrode capacitance sensing module further includes a carrier glass layer; The carrier glass layer covers the outer side of the passivation insulating layer away from the droplet transport channel.

[0008] According to a device for measuring the deposition amount and particle size spectrum of aerial pesticide droplets provided by the present invention, a channel contraction area is provided in the droplet transport channel, and the channel width of the channel contraction area is greater than the diameter of the droplets.

[0009] According to the device for measuring the deposition amount and particle size spectrum of droplets during aerial pesticide application provided by the present invention, the droplet transport channel has multiple curved sections.

[0010] According to a device for measuring the deposition amount and particle size spectrum of aerial pesticide droplets provided by the present invention, a piezoelectric vibrator is installed on the electrode cover at the entrance of the droplet transport channel, and the piezoelectric vibrator vibrates sinusoidally within a preset frequency range.

[0011] According to a device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application provided by the present invention, the droplet collector comprises: a dielectric carrier liquid supply device, wherein the dielectric carrier liquid supply device is loaded with dielectric carrier liquid; A mist droplet receiving tray is connected to the dielectric carrier liquid supply device and is used to receive the mist droplets settled during the application process.

[0012] According to the device for measuring the deposition amount and particle size spectrum of aerial pesticide droplets provided by the present invention, the thickness of the passivation insulating layer is no more than 2 microns.

[0013] According to the present invention, a device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application further includes a liquid collecting tank; The inlet of the liquid collecting tank is connected to the outlet of the droplet transport channel through the micro-flow control pump.

[0014] According to the device for measuring the deposition amount and particle size spectrum of aerial pesticide spraying droplets provided by the present invention, the dielectric carrier liquid is silicone oil.

[0015] According to a device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application provided by the present invention, the processor is used to determine the amount of droplet deposition and particle size spectrum based on the capacitance signal generated by the coplanar electrode during the process of the oil-based mixture flowing through the droplet transport channel, specifically including: determining each capacitance peak in the capacitance signal; determining the number of the droplets received and settled by the droplet collector according to the number of the capacitance peaks; Inputting each of the capacitance peak values into a droplet size decision model to obtain a droplet size corresponding to each droplet output by the droplet size decision model; Calculating the deposition amount received by the droplet collector during the application process according to the droplet particle size of each droplet; Determining the particle size spectrum of the droplets received by the droplet collector during the application process according to the distribution of the droplet particle sizes of all the droplets; The droplet size decision model is obtained by training based on historical droplet samples and droplet size labels corresponding to each historical droplet sample.

[0016] According to the device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application provided by the present invention, the processor calculates the amount of deposition received by the droplet collector during the pesticide application process according to the droplet particle size of each droplet as follows: ; in, Q is the deposition amount, n is the number of droplets, D i For the i The diameter of the droplets.

[0017] The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application provided by the present invention establishes a capacitive sensing area based on coplanar electrodes, and utilizes the difference in dielectric constant between the dielectric carrier liquid and the droplets to change the capacitance signal in the sensing area. The number of droplets and the corresponding particle size of each droplet can be inferred from the capacitance signal. This device can achieve real-time measurement, improve measurement efficiency, has good environmental adaptability, and provides an intelligent detection method for the quality assessment of aerial pesticide application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a structural schematic diagram of the device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application provided by the present invention.

[0020] Figure 2It is a structural schematic diagram of the coplanar electrode capacitance sensing module provided by the present invention.

[0021] Figure 3 This is a schematic diagram of the arrangement of three groups of coplanar electrode capacitance sensing modules provided by the present invention.

[0022] Figure 4 It is a schematic diagram of a capacitance value change curve when a droplet passes through a coplanar electrode capacitance sensing module provided by the present invention.

[0023] Figure 5 It is a schematic diagram of a capacitance value change curve when a mist droplet with a particle size of 250 microns passes through a coplanar electrode capacitance sensing module provided by the present invention.

[0024] Figure 6 It is a schematic diagram of a capacitance value change curve when a mist droplet with a particle size of 480 microns passes through a coplanar electrode capacitance sensing module provided by the present invention.

[0025] Figure 7 It is a schematic diagram of a capacitance value change curve when a mist droplet with a particle size of 700 microns passes through a coplanar electrode capacitance sensing module provided by the present invention.

[0026] Figure 8 It is a fitting schematic diagram of the droplet size decision model provided by the present invention.

[0027] Reference numerals: Droplet collector 1; dielectric carrier liquid supply device 11; droplet receiving tray 12; coplanar electrode capacitance sensor module 2; passivation insulation layer 21; electrode cover 22; coplanar electrode 23; glass carrier layer 24; microfluidic control pump 3; processor 4; liquid collection tank 5. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0029] It should be noted that, in the description of the present invention, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. Without further limitation, the phrase "comprises a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus comprising the elements. Terms such as "upper" and "lower" indicate positions or relationships based on those shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation, and are therefore not to be construed as limitations on the present invention. Unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be broadly construed, for example, to mean fixed, removable, or integral; mechanical or electrical; direct or indirect through an intermediary; or internal communication between two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The following combination Figures 1-8 The present invention describes a device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application.

[0031] Figure 1 Schematic diagram of the structure of the device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application provided by the present invention. Figure 1 As shown, the measuring device includes but is not limited to: a droplet collector 1, a coplanar electrode capacitance sensing module 2, a microfluidic control pump 3 and a processor 4, wherein: As one of the key components of the entire aerial pesticide spraying droplet deposition and particle size spectrum measurement device, the droplet collector 1 is mainly used to receive the settled droplets during the spraying process and mix the droplets with a dielectric carrier liquid to generate an oil-based mixture.

[0032] During the spraying operation, after the droplets are sprayed from the spray nozzle, they will gradually settle to the ground under the influence of gravity and air resistance in the air. The droplet collector 1 is usually installed on the ground or on the surface of the plants in the spraying area, and its structural design needs to consider how to collect the droplets efficiently. For example, the droplet collector 1 can be a receiving tray with a large surface area, and the surface of the receiving tray is covered with a hydrophilic material so that the droplets can adhere to it more easily. After the droplets settle on the receiving tray of the droplet collector 1, the dielectric carrier liquid (such as silicone oil) will contact and mix with the droplets under the action of gravity or the microfluidic control pump 3 to form an oil-based mixture.

[0033] It should be noted that the design of the droplet collector 1 must ensure that each droplet, after settling, can contact the dielectric carrier liquid (e.g., silicone oil) and form an oil-based mixture, while also preventing droplet aggregation. For example, the entire droplet collector 1 may include a droplet receiving tray 12 and a dielectric carrier liquid supply device 11. The droplet receiving tray 12 may have a porous or grid-like structure, with the pores slightly larger than the maximum droplet diameter, to ensure that droplets are distributed individually on the droplet receiving tray 12 and prevent aggregation. Furthermore, the surface of the droplet receiving tray 12 may be coated with a hydrophilic material to facilitate droplet adhesion and dispersion.

[0034] The dielectric carrier fluid selected here is immiscible with the droplets and has different dielectric constants, a crucial prerequisite for droplet detection based on capacitive sensing. This difference in dielectric constant causes a significant change in the capacitance signal when the oil-based mixture passes through the capacitive sensing area of the coplanar electrodes, enabling processor 4 to effectively detect the number and size of droplets based on this capacitance signal change.

[0035] Figure 2 Schematic diagram of the structure of the coplanar electrode capacitance sensing module provided by the present invention. Figure 2 As shown, the coplanar electrode capacitance sensing module 2 includes but is not limited to: a passivation insulating layer 21, an electrode cover 22, a coplanar electrode 23 and a glass carrier layer 24, wherein: the coplanar electrode capacitance sensing module 2 is a core component for realizing the detection of droplet parameters, including the number of droplets deposited on the droplet collector 1, the particle size of each droplet, and the particle size spectrum of all droplets.

[0036] The coplanar electrode capacitance sensing module 2 mainly includes a passivation insulating layer 21 and an electrode cover 22 . The passivation insulating layer 21 and the electrode cover 22 cooperate to form a droplet transport channel that runs through the entire coplanar electrode capacitance sensing module 2 .

[0037] The passivation insulating layer 21 is an insulating structure disposed on the surface of the coplanar electrodes 23. It serves to electrically insulate and physically protect the coplanar electrodes 23 without affecting the electric field distribution. The passivation insulating layer 21 can be a rectangular sheet and slightly larger than the distribution area of the coplanar electrodes 23 to ensure complete coverage and mechanical support. The passivation insulating layer 21 can be made of polydimethylsiloxane (PDMS), polyimide (PI), or other polymeric materials with high dielectric strength, good chemical stability, and easy film formation.

[0038] The passivation insulating layer 21 can effectively prevent the oil-based mixture from directly contacting the electrodes and interfering with the electric field distribution by isolating the coplanar electrodes 23 from the oil-based mixture, thereby ensuring that the capacitance change in the coplanar electrode capacitance sensing area is only caused by the difference in dielectric constant between the dielectric carrier liquid and the droplets, providing a basis for the subsequent processor 4 to accurately detect the number and particle size of droplets.

[0039] It should be noted that the thickness of the passivation insulating layer 21 is a key factor, directly affecting the sensitivity and response speed of the coplanar electrode capacitance sensing module. The thinner the passivation layer, the stronger the equivalent electric field interaction between the droplets and the coplanar electrodes, which can cause more significant capacitance changes and help improve the accuracy of identifying small droplet particle sizes. Conversely, if the passivation layer is too thick, it will weaken the electric field penetration ability, resulting in a weakened signal response and affecting detection accuracy.

[0040] Optionally, the thickness of the passivation insulating layer 21 can be controlled within a relatively thin range, thereby achieving electrode insulation while maximizing the sensitivity of the coplanar electrode capacitance sensing area to differences in dielectric constant. In actual fabrication, the film can be formed by spin coating a diluted PDMS solution, combined with spin speed control and thermal curing processes to achieve precise thickness control, ensuring that the passivation layer achieves a good balance between structural strength and electrical performance.

[0041] Alternatively, as Figure 2 As shown, the passivation insulating layer 21 can be positioned above the coplanar electrode 23 and cooperates with the electrode cover 22 to form a droplet transport channel that runs through the entire coplanar electrode capacitive sensing module 2. A coplanar electrode 23 composed of at least two electrodes is embedded in the passivation insulating layer 21, and the inlet of the droplet transport channel is connected to the outlet of the droplet collector 1. Figure 2 The arrow from left to right in the figure indicates the flow direction of the oil-based mixture, that is, the liquid formed by the mixture of the dielectric carrier liquid and the collected droplets flows along the droplet transport channel from the droplet collector 1 to the coplanar electrode capacitive sensing area.

[0042] Specifically, the coplanar electrode 23 can be a conductive structure arranged on the surface of the glass carrier layer 24 and embedded in the passivation insulating layer 21, which is used to form a stable coplanar electrode capacitance sensing area. Its shape can be two parallel strip electrodes, or it can be designed into a structure such as a mutual finger type, a comb type or a rectangular ring type according to the detection accuracy requirements to adjust the electric field distribution range and sensitivity. The electrode material can be selected from metal materials such as copper, chromium, gold or platinum with stable conductive properties and compatible with micro-nano manufacturing processes. By establishing a stable coplanar electrode capacitance sensing area, the coplanar electrode 23 makes the change in dielectric constant caused by the droplets passing through the electrode area in the oil-based mixture reflected as a change in capacitance signal, thereby achieving accurate detection of the number and particle size of droplets.

[0043] It should be noted that the current traditional sandwich electrode structure is a structure in which two electrodes are respectively placed on the upper and lower sides of the droplet transport channel, sandwiching the liquid in the middle to form a vertical electric field. The present invention takes into account that a larger coplanar electrode capacitance sensing area not only increases the probability of droplets passing through the coplanar electrode capacitance sensing area, but also prolongs the time that droplets interact with the coplanar electrode capacitance sensing area, making the capacitance change caused by each droplet more significant and the waveform signal clearer, which helps to improve the response sensitivity and recognition accuracy of processor 4 to tiny droplets.

[0044] As an optional embodiment, the coplanar electrode 23 of the present invention can arrange two electrodes at intervals on the same plane. The coplanar electrode 23 of the present invention can form a transverse electric field on the same plane. The electric field lines pass through the liquid horizontally from one electrode to the other electrode, presenting a "hemispherical" arc distribution, forming a coplanar electrode capacitance sensing area with a wider spatial distribution in the droplet transport channel.

[0045] The inlet of the droplet transport channel is connected to the outlet of the droplet collector 1 to ensure that the oil-based mixture can flow smoothly from the droplet collector 1 into the coplanar electrode capacitance sensing module 2 to detect the number of droplets and the droplet particle size.

[0046] A micro-flow control pump 3 is used to control the flow rate of the oil-based mixture flowing through the droplet transport channel.

[0047] Specifically, the microfluidic control pump 3 is a core component for regulating the flow rate of the oil-based mixture through the droplet transport channel. Its function is to control the passage of droplets through the coplanar electrode capacitance sensing area of the coplanar electrode capacitance sensing module 2. Its shape can be a compact rectangular parallelepiped structure, suitable for integrated installation in the droplet transport channel.

[0048] Optionally, the microfluidic control pump 3 may include a pump casing and a pump body. The pump body is used to guide and pressure-displace the oil-based mixture's flow path, while the pump casing encases the pump body, providing structural support and protection. The pump body in the microfluidic control pump 3 can be constructed from corrosion-resistant, high-strength materials such as polypropylene (PP) and polytetrafluoroethylene (PTFE) to accommodate the long-term flow requirements of dielectric carrier fluids such as silicone oil. Precisely controlling the pump speed effectively regulates the droplet transport rhythm, improving the stability of capacitance detection and the accuracy of particle size identification.

[0049] As an optional embodiment, the microfluidic control pump 3 can be a peristaltic pump or a syringe pump, which can control the flow rate between tens of microliters and hundreds of microliters per minute to meet the detection requirements under different concentrations and particle size ranges. Specifically, the microfluidic control pump 3 can be driven by a motor and cooperate with a speed controller and a visual host computer system connected thereto to achieve flow rate regulation. After inputting the set parameters in the visual host computer system connected to the speed controller, the flow rate adjustment operation is automatically performed. The above-mentioned set parameters may include target flow rate value, flow range, pump speed adjustment cycle, etc. After inputting the set parameters on the interface of the visual host computer system, the speed controller automatically adjusts the motor speed according to the received control instructions, thereby accurately controlling the flow rate of the oil-based mixture in the droplet transport channel.

[0050] Furthermore, the microfluidic control pump 3 can adjust the flow rate in combination with specific operating scenarios. For example, in large-scale, high-intensity pesticide application operations, such as those with fast flight speeds, large spray volumes, and high droplet density, the pump speed of the microfluidic control pump 3 can be appropriately increased to speed up the flow rate of the oil-based mixture, thereby preventing droplets from agglomerating or overlapping in the channel and ensuring that each droplet passes through the coplanar electrode capacitance sensing area in sequence. In refined pesticide application or low-density spraying scenarios, such as small-scale precision spraying in orchards and greenhouses, where the number of droplets is small and the deposition rate is low, the pump speed can be appropriately reduced to allow the droplets to stay in the sensing area longer, thereby increasing the sensing intensity of the capacitance signal of individual tiny droplets and enhancing the stability and accuracy of droplet size recognition.

[0051] The liquid collection tank 5 is a liquid collection unit provided at the end of the microfluidic control pump 3, and is used to store the oil-based mixture discharged from the droplet collector 1 through the coplanar electrode capacitance sensor module 2 and the microfluidic control pump 3. The shape can be a sealed or semi-open rectangular or cylindrical container, and the specific structure can be flexibly designed according to the device volume and application scenario. By constructing a closed recovery path, the liquid collection tank 5 effectively avoids backflow or retention caused by liquid residue in the channel, achieving complete closed-loop management of the detection process and safe control of liquid output. For example, in the spraying field environment, the liquid collection tank 5 can be quickly replaced and regularly cleaned through a valve port structure to ensure the continuous operation and clean maintenance of the system.

[0052] Alternatively, as Figure 1As shown, the microfluidic control pump 3 can be positioned downstream of the coplanar electrode capacitance sensing module 2, i.e., in the middle section connecting the outlet of the droplet transport channel and the liquid collection tank 5. The inlet end of the microfluidic control pump 3 (i.e., the side where the fluid enters the pump) is connected to the outlet of the coplanar electrode capacitance sensing module 2, while the outlet end (the side where the fluid exits the pump) can be connected to the liquid collection tank 5 via a fluid conduit, thereby establishing a continuous and closed fluid transport path. This arrangement prevents the fluid suction or pressure fluctuations generated by the pump from being transmitted back to the front end during operation, thereby disrupting the natural settling of droplets in the droplet collector 1.

[0053] It should be noted that, in the present invention, multiple groups of coplanar electrode capacitance sensing modules 2 can be arranged in parallel, thereby realizing multi-channel droplet detection at the same time.

[0054] Figure 3 This is a schematic diagram of the arrangement of three groups of coplanar electrode capacitance sensing modules provided by the present invention. Figure 3 As shown in the example, three groups of coplanar electrode capacitance sensing modules are labeled A, B, and C, and are arranged in parallel on different droplet transport channels. The input end of each group of coplanar electrode capacitance sensing modules is connected to the entrance of the corresponding droplet transport channel, and the output end is connected to the exit of the corresponding droplet transport channel. Each group of coplanar electrode capacitance sensing modules can independently complete the identification of the number and particle size of droplets. This parallel structure can achieve multi-channel synchronous monitoring, thereby improving the detection efficiency of droplets in different areas. For example, in an aerial spraying operation, three groups of coplanar electrode capacitance sensing modules 2 can be arranged in the three corresponding nozzle areas under the aircraft wing to achieve synchronous sampling and analysis, thereby improving the detection efficiency of droplets.

[0055] Furthermore, Figure 3 The coplanar electrode capacitive sensing module group B in the figure is used to illustrate the entire process of a single droplet passing through the coplanar electrode capacitive sensing area. The numbers 1 to 5 marked inside the module correspond to the following stages: No. 1: The droplet has not yet entered the coplanar electrode capacitance sensing area; No. 2: The front of the droplet enters the capacitive sensing area of the coplanar electrode; Number 3: When the droplet completely enters the coplanar electrode capacitance sensing area; No. 4: The droplet gradually leaves the coplanar electrode capacitive sensing area; Number 5: The droplet completely leaves the coplanar electrode capacitive sensing area.

[0056] Figure 4 Schematic diagram of the capacitance change curve of the fog droplet passing through the coplanar electrode capacitance sensing module provided by the present invention. Figure 4As shown, when the droplet has not yet entered the coplanar electrode capacitance sensing area (corresponding to number 1), the capacitance maintains the initial value, that is, the capacitance value when there is only dielectric carrier liquid in the coplanar electrode capacitance sensing area; as the front of the droplet enters the coplanar electrode capacitance sensing area (corresponding to number 2), the capacitance begins to rise; when the droplet completely enters the coplanar electrode capacitance sensing area (corresponding to number 3), the capacitance reaches a peak value; then the droplet gradually leaves the coplanar electrode capacitance sensing area (corresponding to number 4), and the capacitance gradually decreases; finally, the droplet completely leaves (corresponding to number 5), and the capacitance returns to the initial level.

[0057] Optionally, the present invention fully considers the corresponding relationship between the motion trajectory of the droplets in the coplanar electrode capacitance sensing module and the capacitance signal response during the design process. Based on this law, the following is adopted: Figure 3 The structural layout shown is similar to Figure 4 The signal analysis method shown enables the position change of the droplet in the coplanar electrode capacitance sensing area to be intuitively reflected through the change of the capacitance signal.

[0058] The processor 4 is configured to determine the deposition amount and particle size spectrum of the droplets based on the capacitance signal generated by the coplanar electrodes during the process of the oil-based mixture flowing through the droplet transport channel.

[0059] Processor 4 is the core information processing unit for receiving and analyzing the capacitance signal generated by the coplanar electrode capacitance sensing module 2 during the flow of the oil-based mixture through the droplet transport channel. It can accurately identify and count the deposition amount and particle size spectrum of the droplets. Due to the significant difference in dielectric constant between the dielectric carrier liquid (such as silicone oil) and the droplets, for example, the dielectric constant of silicone oil is 2.4, while the dielectric constant of water is 81, when the droplets entrained in the oil-based mixture pass through the coplanar electrode capacitance sensing area, the capacitance value will cause a significant sudden change in an instant, forming a clear capacitance peak. Each time a droplet passes through the sensing area, an independent capacitance mutation peak will be generated. Therefore, the number of capacitance peaks corresponds to the number of droplets. The processor 4 can determine the total number of droplets by counting the number of peaks in the capacitance signal.

[0060] It should be noted that, although in actual applications, the droplets may contain a certain proportion of other components and their overall dielectric constant may deviate slightly from that of pure water, since the main component of the droplets is water, their dielectric constant is still much higher than that of dielectric carriers such as silicone oil. Therefore, in the droplet detection, the droplets are analyzed and processed approximately according to the dielectric constant of water. The processor 4 can still ensure high recognition accuracy and stability when identifying the capacitance peak and counting the number of droplets.

[0061] Furthermore, because the capacitance change is affected by the droplet's own dielectric properties and particle size, larger droplets occupy a larger volume, displacing more dielectric carrier fluid, and thus causing a more significant capacitance change. In the present invention, a functional relationship model between capacitance peak value and droplet size is established, using capacitance peak value as the independent variable and droplet size as the dependent variable. This allows processor 4 to infer the corresponding droplet size based on the value of each capacitance peak value.

[0062] Specifically, the present invention can establish a functional relationship model between peak capacitance and droplet size based on a method of fitting historical experimental data. This functional relationship model uses peak capacitance as the independent variable and droplet size as the dependent variable. It utilizes a large amount of peak capacitance data for droplets of known particle sizes in the coplanar electrode capacitance sensing module 2, and then constructs a mapping function between peak capacitance and droplet size through a regression model. This regression model can be trained using linear fitting or a machine learning method based on support vector regression (SVR).

[0063] It should be noted that, compared to the capacitance change value, the present invention chooses to use the capacitance peak as the dependent variable because the capacitance peak reflects the most obvious and prominent part of the capacitance change when each droplet passes through the sensing area, which is less affected by interference and is more easily accurately identified. This not only improves the accuracy of the judgment, but also makes the processing results more stable and reliable. For example, when the droplet passing speed fluctuates or the droplet rotates or deforms slightly in the channel, the overall change process of the capacitance signal may be elongated or become irregular, causing the capacitance change value to be greatly affected and the extraction result to be unstable. As the maximum point in the signal, the capacitance peak is often not disturbed by these detailed changes and can still accurately reflect the main differences in droplet particle size. Therefore, it is more suitable as the dependent variable of the functional relationship model.

[0064] After obtaining the number and particle size data of all droplets, the processor 4 can further calculate the droplet deposition amount per unit area or per unit time, and count the droplet distribution frequency of each particle size segment, thereby constructing complete particle size spectrum information.

[0065] Optionally, to facilitate user operation and result display, the processor 4 can also be connected to a host computer system to display results such as particle size spectrum, deposition amount, and droplet number in real time through a graphical interface. The host computer can use a graphical development platform to build a human-computer interaction interface to realize data visualization, export, and analysis functions.

[0066] This embodiment provides a device for measuring the amount of droplet deposition and particle size spectrum from aerial pesticide application. This device establishes a capacitive sensing area based on coplanar electrodes. The difference in dielectric constant between the dielectric carrier liquid and the droplets changes the capacitance signal in the sensing area. The capacitance signal can be used to infer the number of droplets and the corresponding particle size of each droplet. This device enables real-time measurement, improves measurement efficiency, and exhibits good environmental adaptability, providing an intelligent detection method for aerial pesticide application quality assessment. Compared to existing image processing methods, such as those based on water-sensitive paper, the capacitive sensing-based detection device provided by this invention not only offers advantages such as high real-time performance, excellent detection accuracy, and wide applicability, but also significantly reduces manual intervention and post-processing time, overcoming existing issues such as sample failure, long processing cycles, and limited experimental scenarios.

[0067] In another embodiment provided by the present invention, the coplanar electrode capacitance sensing module further includes a carrier glass layer; the carrier glass layer covers the outer side of the passivation insulating layer away from the droplet transport channel.

[0068] The glass carrier layer 24 is located at the bottom of the coplanar electrode capacitive sensing module 2 and is used to support the coplanar electrodes 23 and the passivation insulating layer 21 above them. The glass carrier layer 24 can be a rectangular flat plate with the size of a standard microscope slide. It can be made of a glass material with high light transmittance, high mechanical strength, and excellent electrical insulation properties, such as borosilicate glass. Depending on the specific application, transparent polymer materials such as polycarbonate (PC) and polyethylene terephthalate (PET) can also be used.

[0069] The present invention provides a device for measuring the deposition amount and particle size spectrum of droplets from aerial pesticide application. By arranging a carrier glass layer in a coplanar electrode capacitance sensing module and covering it on the outer side of the passivation insulating layer facing away from the droplet transport channel, the device can enhance the mechanical strength of the module while providing a flat and stable support base for the electrode structure, preventing structural deformation caused by external impact or operational stress, thereby ensuring the morphological consistency and sensing accuracy of the capacitance detection area; at the same time, the glass material used in the carrier glass layer has good electrical insulation properties, which helps to shield environmental electrical noise and interference of adjacent structures on the electric field distribution, further improving the stability of the capacitance signal output.

[0070] In another embodiment provided by the present invention, a channel contraction area is provided in the droplet transport channel, and the channel width of the channel contraction area is greater than the diameter of the droplets.

[0071] Specifically, the channel contraction region refers to a locally narrowed area of geometric structure formed in a certain section of the droplet transport channel, making the cross-sectional width of this section of the channel larger than the maximum diameter of the target droplets, typically 1.1 to 1.3 times the droplet diameter. By setting up such a contraction structure, the flow restriction effect in fluid dynamics can be effectively utilized to geometrically restrict the arrangement of droplets during the transport process, thereby forcing droplets to pass through the coplanar electrode capacitive sensing area one by one when passing through this area, avoiding signal overlap or interference caused by multiple droplets entering side by side at the same time, and improving the resolution and recognition accuracy of the capacitive signal.

[0072] Specifically, in narrow droplet transport channels, droplets or particles are forced to form linear queues due to the combined effects of fluid shear force, interfacial tension, and channel boundaries, enabling automatic, intermittent flow. This makes it suitable for scenarios such as continuous detection or individual analysis. In this device, the contraction region of the droplet transport channel can be precisely constructed using micro-nanofabrication techniques (such as soft lithography or micromilling) and can be customized to the target droplet size range. For example, for droplets with a maximum size of 200 microns, the contraction region of the droplet transport channel can be designed as a cylindrical segment with a diameter of approximately 220 microns.

[0073] Optionally, considering that the device needs to adapt to the droplet size distribution under different spraying conditions, the channel contraction area can also be designed as a modular replaceable structure, or a flexible channel wall with adjustable width can be used (for example, using shape memory alloys or flexible polymers to control boundary deformation) to achieve dynamic adaptation to droplets of different particle sizes, thereby improving the versatility and flexibility of the droplet transport channel.

[0074] The device for measuring the deposition amount and particle size spectrum of aerial pesticide droplets provided by the present invention sets a channel contraction area in the droplet transport channel so that the channel width of the area is greater than the droplet diameter. This not only achieves effective control of the droplet movement path at the structural level, preventing multiple droplets from entering the sensing area at the same time and causing capacitance signal interference, but also provides a stable and single detection window for the coplanar electrode capacitance sensing module 2, ensuring that each capacitance signal peak can correspond to a unique droplet passage event. It is one of the key auxiliary structures to ensure that the droplet particle size signal can be independently measured, and is suitable for high-speed detection, batch measurement or pesticide application scenarios with high droplet concentration, effectively improving the accuracy of particle size determination and the overall data availability of the system.

[0075] In another embodiment provided by the present invention, the droplet transport channel has multiple curved sections.

[0076] Specifically, the multi-segment curved section refers to a droplet transport channel that is not a straight-line path, but rather a series of curved structures, such as continuously changing S-, serpentine, Z-, or broken-line curves. This structure can be achieved through microchannel design and processing techniques, such as using PDMS soft lithography to embed a curved channel template into a passivation insulating layer. During processing, the channel's curvature radius is maintained to ensure that the flow stability of the mixture is not affected.

[0077] From the perspective of microfluidic fluid dynamics, the present invention proposes that the curved channel configuration can effectively disrupt the laminar flow of the fluid in a straight channel, creating a certain degree of lateral disturbance. This redistributes the droplets in the mixed liquid during transport, preventing the concentration of droplets in a certain area of the channel due to gravity deposition, wall adhesion, or localized accumulation. This ensures that the droplets remain evenly distributed before entering the coplanar electrode capacitive sensing module. Furthermore, the curved structure also helps the droplets align toward the center of the channel under the action of fluid shear force, thereby improving the stability and reproducibility of the droplets as they pass through the detection area.

[0078] As an optional embodiment, the curved channel design adopted in the present invention can also be combined with the channel contraction structure to jointly construct a more complete droplet screening and alignment mechanism. For example, a channel contraction area is connected after the curved section, so that the droplets appear in a "single row arrangement, passing through in sequence" state when passing through the coplanar electrode capacitance sensing module, effectively improving the timing resolution capability of the capacitance signal.

[0079] It should be noted that the geometry, length, and position of these multiple curved sections can be optimized based on the droplet size, flow rate, and concentration of the spray application scenario. To accommodate different particle size distributions or operating conditions, a modular structure can be employed, allowing for reconfigurable channel paths by replacing curved sections with different configurations.

[0080] The device for measuring the deposition amount and particle size spectrum of aerial pesticide droplets provided by the present invention can improve the spatial distribution of droplets during transportation, reduce the risks of aggregation and deviation, and enhance the quality and passing accuracy of droplets entering the coplanar electrode capacitance sensing module by providing multiple curved sections in the droplet transport channel. This improves the accuracy and repeatability of particle size signal recognition and enhances the adaptability and measurement reliability of the device in various agricultural spraying environments.

[0081] In another embodiment provided by the present invention, a piezoelectric vibrator is installed on the electrode cover 22 at the entrance of the droplet transport channel, and the piezoelectric vibrator vibrates sinusoidally within a preset frequency range.

[0082] Specifically, a piezoelectric vibrator is a driving device that utilizes piezoelectric materials to generate mechanical deformation under alternating current excitation. It is capable of continuously producing small, periodic vibrations within a certain frequency range. In this device, the piezoelectric vibrator can use a piezoelectric ceramic (such as PZT) as the actuator element, which is fixed to the outer surface of the electrode cover 22 near the entrance of the droplet transport channel. Driven by a controller, the vibrator operates in a sinusoidal manner with an adjustable frequency range between 50Hz and 500Hz.

[0083] This invention utilizes microfluidics manipulation. The periodic vibration of a piezoelectric vibrator at the entrance of the droplet transport channel effectively disrupts the interfacial stability of the mixed fluid, causing droplets entering the channel to break apart as individual particles before being entrained by the silicone oil, thereby reducing droplet aggregation or coalescence. This process leverages the coupling between acoustically induced shear disturbances and interfacial tension, resulting in a more uniform and neatly arranged droplet formation.

[0084] Furthermore, the piezoelectric vibrator in this device can be used in conjunction with flow rate control to optimize the dynamic spacing of droplets. For example, in conditions of high droplet density, increasing the vibration frequency can enhance droplet separation. In scenarios with large or easily deformed droplets, the vibration amplitude can be appropriately reduced to avoid fragmentation or signal distortion. The piezoelectric vibrator structure can also be flexibly replaced with a piezoelectric buzzer or surface-mounted piezoelectric film to meet different layout space and cost control requirements.

[0085] As an optional embodiment, when it is necessary to quickly measure the amount of droplet deposition but the requirements for the accuracy of the particle size spectrum are not high, the aerial pesticide application droplet deposition and particle size spectrum measuring device provided by the present invention, by arranging a piezoelectric vibrator on the electrode cover 22 and causing it to generate sinusoidal vibrations within a preset frequency range, can actively disturb the generation state of the droplets before they enter the transport channel, causing the droplets to break one by one and stably separate, effectively improving the arrangement of droplets entering the coplanar electrode capacitance sensing module, reducing the risk of signal overlap, and further enhancing the resolution and reliability of droplet particle size detection. It is suitable for aerial spraying scenarios with high-speed passage and easy particle size overlap.

[0086] In another embodiment provided by the present invention, the droplet collector 1 includes: a dielectric carrier liquid supply device 11, the dielectric carrier liquid supply device 11 is loaded with a dielectric carrier liquid; a droplet receiving tray 12, the droplet receiving tray 12 is connected to the dielectric carrier liquid supply device 11, and is used to receive the droplets settled during the application process.

[0087] Specifically, the dielectric carrier liquid supply device 11 can be a sealed liquid storage container or an integrated micro-pumping system, filled with a liquid medium with low polarity and low dielectric constant, such as silicone oil or fluorocarbon oil. This dielectric carrier liquid is incompatible with water-based pesticide droplets and has a significant difference in dielectric constant from the droplets, which helps achieve high-contrast capacitance signal changes in the coplanar electrode capacitance sensing module. The dielectric carrier liquid supply device 11 can stably output the dielectric carrier liquid through gravity flow, microvalve flow control, or a constant flow pump, and continuously supply the liquid to the droplet receiving tray 12.

[0088] The droplet receiving tray 12 can be a flat-bottomed groove or a shallow tray structure, with a hydrophilic surface treatment to enhance the adhesion and dispersion properties of the droplets after sedimentation. The droplets are deposited on the tray surface during the falling process and form an oil-based mixture after being fully mixed with the dielectric carrier liquid. In order to ensure mixing uniformity and avoid droplet aggregation, the droplet receiving tray 12 can be designed as a grid structure, the surface pore size of which can be slightly larger than the maximum diameter of the droplets, for example, 200 to 500 microns, so that the droplets can fall in individually and remain in a dispersed state. In addition, the bottom or side wall of the droplet receiving tray 12 is pre-set with a liquid inlet connected to the dielectric carrier liquid supply device 11 to ensure that the liquid level is continuously stable.

[0089] In actual applications, the dielectric carrier liquid supply device 11 can also be configured with an insulation layer or a heating module in combination with changes in ambient temperature to prevent the viscosity of the dielectric carrier liquid from increasing at low temperatures, thereby ensuring flow performance and mixing efficiency; and the droplet receiving plate 12 can be designed as a detachable structure to facilitate cleaning, replacement or adaptation to different spraying intensity scenarios.

[0090] The device for measuring the amount of droplet deposition and particle size spectrum in aerial pesticide application provided by the present invention, by providing a droplet collector 1 including a dielectric carrier liquid supply device 11 and a droplet receiving tray 12, can promptly and stably complete the contact and mixing of droplets and dielectric carrier liquid during the application process, thereby ensuring the composition stability of the generated oil-based mixture, thereby improving the detection accuracy and response consistency of the coplanar electrode capacitance sensing module for the number of droplets and particle size. It is suitable for the droplet deposition measurement needs under different application conditions and has good versatility and adaptability.

[0091] In another embodiment provided by the present invention, the thickness of the passivation insulating layer 21 is no more than 2 microns.

[0092] Specifically, a passivation insulating layer 21 is provided in the coplanar electrode capacitive sensing module 2, covering the coplanar electrodes 23. Its function is to provide electrical insulation while protecting the electrodes from corrosion and contamination by droplets or dielectric carrier fluid. The passivation insulating layer 21 can be made of PDMS, a material with excellent flexibility, chemical stability, and dielectric properties, and is widely used for electrode passivation in microfluidic systems.

[0093] In this embodiment, to improve the capacitive response to tiny droplets, the thickness of the passivation insulating layer 21 is controlled to be no greater than 2 microns. This thickness enhances the effective electric field strength between the droplets and the coplanar electrode 23, thereby producing a more significant capacitance change when the droplets pass through the sensing area, which helps enhance the sensor's ability to resolve changes in droplet size.

[0094] The passivation insulating layer 21 can be prepared using a spin coating process. For example, after diluting PDMS and toluene in a mass ratio of 1:3, the film is spin-coated on the glass carrier layer 24 at 4000 rpm for 60 seconds and then cured at 90°C for 1 hour to form a passivation insulating film of uniform thickness. This process can be integrated into the batch manufacturing process of the coplanar electrode capacitive sensing module 2, and exhibits good controllability and consistency.

[0095] In practical applications, reducing the thickness of the passivation insulating layer 21 can also reduce dielectric response delays in droplets, improving signal timeliness. This is particularly useful for continuous, real-time detection of high-speed droplets during aerial pesticide application. For applications in more complex or extreme environments, PDMS can be replaced with other high-dielectric-strength materials, such as polyimide, to maintain dielectric performance while achieving a thickness of no more than 2 microns.

[0096] The device for measuring the deposition amount and particle size spectrum of aerial pesticide droplets provided by the present invention controls the thickness of the passivation insulating layer 21 to no more than 2 microns, thereby not only structurally ensuring the reliable packaging and durability of the coplanar electrode 23, but also functionally improving the response sensitivity and particle size discrimination accuracy of the coplanar electrode capacitance sensing module 2, effectively enhancing the device's ability to identify fine droplets, and improving the applicability and accuracy of the overall measurement system in complex agricultural spraying environments.

[0097] In another embodiment provided by the present invention, a liquid collecting tank 5 is further included; the inlet of the liquid collecting tank 5 is connected to the outlet of the droplet transport channel through the microfluidic control pump 3.

[0098] Specifically, the liquid collection tank 5 collects the oil-based mixture (i.e., the liquid formed by the mixture of droplets and a dielectric carrier fluid) pumped from the end of the droplet transport channel by the microfluidic control pump 3. This serves to temporarily store the liquid, control its discharge, and facilitate secondary sample recovery. This structure not only improves the device's closed-loop liquid transport path but also facilitates subsequent analysis, drainage treatment, or safe transfer. It is particularly suitable for field operations or precision agriculture environments where waste liquid leakage must be avoided.

[0099] The sump 5 can be a sealed or semi-open container. Its capacity is determined by the actual detection time and the droplet transport rate, and can range from 10 to 50 mL. The sump 5 can be made of a corrosion-resistant and organic solvent-resistant polymer material, such as polytetrafluoroethylene or polypropylene, to accommodate long-term contact with dielectric carrier fluids such as silicone oil and fluorinated oil.

[0100] The microfluidic control pump 3, installed between the droplet transport channel and the sump 5, is responsible for delivering the oil-based mixture to the sump 5 at a set flow rate, thereby achieving stable control of the flow rate within the channel. This pump not only ensures that droplets pass sequentially through the coplanar electrode capacitive sensing module 2 during transport, avoiding congestion and signal overlap, but also prevents the oil-based mixture from remaining, stagnating, or backflowing within the pipeline.

[0101] In practical applications, the liquid collection tank 5 can also be equipped with a liquid level monitoring module, or a transparent window can be used to facilitate manual observation of the liquid accumulation status to assist in adjusting the spraying parameters or maintaining the equipment. In situations where samples need to be retained for offline testing, the liquid collection tank 5 can also be designed as a detachable structure for easy replacement and cleaning.

[0102] The device for measuring the deposition amount and particle size spectrum of droplets from aerial pesticide application provided by the present invention can realize the unified recovery and management of the oil-based mixture by arranging a liquid collecting tank 5 downstream of the microfluidic control pump 3 and connecting its inlet to the outlet of the droplet transport channel, thereby improving the liquid path closed-loop design of the device, enhancing the safety and maintainability of the system operation, and providing convenience for subsequent sample analysis or reuse, further enhancing the practicality and environmental friendliness of the device in the environment of agricultural precision pesticide application.

[0103] In another embodiment provided by the present invention, the dielectric carrier fluid is silicone oil.

[0104] Specifically, silicone oil is a type of synthetic organosilicon compound based on polysiloxane. It exhibits excellent chemical inertness, electrical insulation, thermal stability, and low surface tension. It is a commonly used dielectric material in microfluidic systems and capacitive sensing technologies. In the device for measuring the deposition and particle size spectrum of aerial pesticide spraying droplets provided by the present invention, silicone oil is stored in a dielectric carrier fluid supply device 11 and continuously delivered to a droplet receiving tray 12 during the spraying operation, where it mixes with the settling droplets to form an oil-based mixture.

[0105] Silicone oil has a dielectric constant of approximately 2.4, far lower than that of mist droplets (approximately 81). Therefore, as mist droplets enter the coplanar electrode capacitive sensing module 2 and become encapsulated by the silicone oil, the equivalent dielectric constant of the sensing area changes significantly, causing a sudden change in capacitance. By extracting and analyzing this capacitance change, processor 4 can accurately identify the presence, quantity, and particle size of mist droplets. This capacitance-based recognition mechanism requires sufficient dielectric contrast between the continuous phase medium and the discrete phase mist droplets, and silicone oil is an ideal material for this purpose.

[0106] In actual use, silicone oil not only stably encapsulates droplets without dissolving or chemically reacting with them, but also maintains low volatility and a wide temperature range, making it particularly suitable for aerial spraying operations, characterized by large temperature differences and unstable airflow. Furthermore, the viscosity of silicone oil can be selected based on demand. Common silicone oil grades of 5 cSt or 10 cSt (5 cSt or 10 cSt indicate the kinematic viscosity of the silicone oil. A higher number indicates a thicker, slower-flowing liquid; a lower number indicates a thinner, faster-flowing liquid) maintain excellent fluidity while effectively encapsulating droplets of varying particle sizes.

[0107] The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application provided by the present invention uses silicone oil as the dielectric carrier liquid. This not only ensures that the capacitance difference between the oil-based mixture and the electrode is sufficiently significant, thereby improving the accuracy of capacitance sensing, but also ensures the chemical stability and measurement consistency of the system under different operating environments, thereby enhancing the engineering practicality and environmental compatibility of the entire measuring device in the field of precision agricultural pesticide application.

[0108] Figure 5 It is a schematic diagram of a capacitance value change curve when a mist droplet with a particle size of 250 microns passes through a coplanar electrode capacitance sensing module provided by the present invention. Figure 6 It is a schematic diagram of a capacitance value change curve when a mist droplet with a particle size of 480 microns passes through a coplanar electrode capacitance sensing module provided by the present invention. Figure 7 This is a schematic diagram of the capacitance change curve when a mist droplet with a particle size of 700 microns passes through the coplanar electrode capacitance sensing module provided by the present invention. Figure 5 、 Figure 6 、 Figure 7 The horizontal axis is time, the unit is milliseconds (ms), and the vertical axis is capacitance, the unit is femtofarad (fF). Figure 5 、 Figure 6 、 Figure 7 As shown, as droplet size increases, the corresponding capacitance peak also gradually increases, indicating that droplets of different sizes induce significant differences in the instantaneous capacitance change when passing through the coplanar electrode capacitance sensing area. Based on this principle, the present invention can use the capacitance peak to infer the droplet size, thereby determining the droplet deposition amount and particle size spectrum.

[0109] The present invention provides a device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application. The processor 4 is used to determine the amount of droplet deposition and particle size spectrum based on the capacitance signal generated by the coplanar electrode during the process of the oil-based mixture flowing through the droplet transport channel, mainly including but not limited to the following steps: Step 101: determining each capacitance peak value in the capacitance signal; Specifically, the capacitance peak refers to the local maximum value that appears on the signal curve of capacitance changing with time, which usually corresponds to the capacitance mutation generated when a single droplet completely enters the detection area of the coplanar electrode 23. Figures 5 to 7 As shown, droplets of different particle sizes (such as 250 microns, 480 microns, and 700 microns) cause capacitance changes with different amplitudes when passing through the detection area.

[0110] Optionally, the value of the capacitance peak value can be obtained by real-time sampling of the capacitance signal output by the coplanar electrode capacitance sensing module 2 by the processor 4, and through the following steps: First, the processor 4 sets a capacitance reference value, that is, the stable capacitance value of the system when no droplets pass through, and then the processor 4 continuously collects the capacitance signal and determines whether there is a sudden increase that is significantly higher than the capacitance reference value as a basis for judging that the droplets may enter the sensing area. Once a significant increase in the capacitance value is identified, the processor 4 continuously tracks the capacitance change, records the dynamically changing capacitance value, and after identifying a complete "rise-fall" or "rise-fall-rise-fall" capacitance change waveform, the maximum value in the capacitance change waveform is used as the capacitance peak value of the droplet. For example, the initial stable capacitance of coplanar electrode capacitance sensing module 2 is 2.60fF. When a droplet passes through the coplanar electrode capacitance sensing area, the capacitance signal suddenly changes, with the recorded capacitance sampling values being: 10fF, 30fF, 50fF, 60.1fF, 60.6fF, 60.9fF, 60.4fF, 60.7fF, 61.2fF, and 60.8fF. Processor 4 identifies this "rise-fall-rise-fall" capacitance change waveform and extracts the maximum value of 61.2fF, identifying it as the capacitance peak corresponding to the droplet.

[0111] Step 102: determining the number of the droplets received and settled by the droplet collector 1 according to the number of the capacitance peaks; Specifically, each capacitance peak corresponds to a droplet entrained in silicone oil and passing through the coplanar electrode capacitance sensing area. Therefore, by counting the capacitance peaks per unit time, the total number of droplets received by the droplet collector 1 can be calculated. Compared to traditional image recognition methods, this approach offers greater real-time performance and environmental adaptability, and is unaffected by factors such as lighting, background, or visual overlap. It is particularly suitable for high-speed, high-volume spray monitoring scenarios.

[0112] Figure 8 : is a fitting diagram of the droplet size decision model provided by the present invention, wherein the abscissa is the capacitance peak value, the unit is femtofarad (fF), and the ordinate is the droplet size, the unit is micrometer (μm). Figure 8 As shown, the fitting process of the entire droplet size decision model may include but is not limited to the following steps: Step 103: Input each of the capacitance peaks into a droplet size decision model to obtain the droplet size corresponding to each droplet output by the droplet size decision model; the droplet size decision model is trained based on historical droplet samples and the droplet size label corresponding to each historical droplet sample.

[0113] Specifically, if Figure 8 As shown in the figure, the droplet size decision model can be a machine learning model built based on a supervised learning strategy, with the input being the capacitance peak and the output being the droplet size. The model inputs a series of capacitance response signals of droplets of known size in an experimental environment and uses a regression algorithm (such as linear regression or support vector regression) to fit the capacitance difference to form a mapping relationship between the capacitance difference and the particle size. For example, the model can fit a function of the form , where y is the droplet size and x is the capacitance peak. The processor 4 inputs each capacitance peak into the model during real-time detection to obtain the corresponding droplet size value.

[0114] As an optional embodiment, Figure 8 As shown, the present invention can construct a fitting function y=9.6273x+35.622 based on a linear regression method to express the linear relationship between the capacitance peak and the droplet size. Figure 8 The coefficient of determination R given in 2 =0.9936, which is calculated based on the proportional relationship between the sum of squares of the model residuals (the sum of the squares of the differences between the predicted values and the true values) and the total sum of squares (the sum of the squares of the differences between all true values and their means). It is used to measure the degree of fit of the model to the sample data. The closer the value is to 1, the better the model fits the sample data.

[0115] Step 104: Calculating the deposition amount received by the droplet collector 1 during the pesticide application process according to the droplet particle size of each droplet; Specifically, the deposition volume refers to the total volume of all collected droplets during the application process, and the unit is usually microliters ( This deposition parameter can be used to evaluate the actual landing effect of the spray dosage, helping to adjust the spray flow rate or optimize the flight height and speed.

[0116] Step 105: determining the particle size spectrum of the droplets received by the droplet collector 1 during the pesticide application process based on the distribution of the particle sizes of all the droplets; Specifically, the particle size spectrum is a key statistical indicator to describe the characteristics of droplet size distribution, usually expressed as D v0.1 (10% volume distribution particle size), D v0.5 (volume median diameter, VMD) and D v0.9 The processor 4 constructs a cumulative distribution curve based on the collected particle size data and calculates the corresponding statistical value.

[0117] like Figure 8 As shown in the figure, the continuous particle size information output by the droplet size decision model can also be used to draw the probability density function curve, and then evaluate the particle size distribution width (Relative Span, RS) or the small particle volume fraction (such as V100%, V150%, V200%), providing data support for the evaluation of spraying uniformity and penetration.

[0118] Specifically, the calculation formulas for VMD and RS are as follows: (1) (2) in Indicates the The particle size of the droplets, Indicates particle size The number or volume weight of droplets; D v0.1 、D v0.5、 D v0.9 are the particle size values corresponding to when the cumulative volume distribution reaches 10%, 50%, and 90%, respectively, where D v0.5 The VMD is the volume median diameter of the distribution, while the RS reflects the width of the particle size distribution. These indicators can be used to measure droplet size concentration, spray uniformity, and the risk of liquid drift during the spray process, assisting the system in spraying quality control and parameter optimization.

[0119] The device for measuring droplet deposition and particle size spectrum for aerial pesticide application provided by the present invention can achieve real-time quantitative evaluation of the pesticide application effect by analyzing and processing the coplanar electrode capacitance signals, combining droplet number statistics, particle size prediction models and volume accumulation calculations, and provides a complete closed-loop feedback system for agricultural precision spraying. It has good adaptability and promotion value under different crop types, climate environments and pesticide application strategies.

[0120] In another embodiment provided by the present invention, the processor 4 in step 104 calculates the deposition amount received by the droplet collector 1 during the application process according to the droplet particle size of each droplet using the following specific calculation formula: (3) in, Q is the deposition amount, n is the number of droplets, D i For the i The diameter of the droplets.

[0121] Specifically, the formula is based on the sphere volume calculation formula Assuming that the droplets remain approximately spherical after being wrapped in a dielectric carrier liquid (such as silicone oil), the processor 4 obtains the particle size of each droplet in step 103 and substitutes the particle size data into the above expression in sequence, cumulatively summing the obtained droplet volume as the total deposition amount Q of the droplet collector 1 in the current spraying cycle. If the particle size unit is micrometer, Q can be further converted into mass deposition amount ( g) or volume concentration ( L / cm²).

[0122] Optionally, in order to improve the calculation accuracy, the processor 4 can pre-process the original particle size data, such as removing low signal-to-noise ratio peaks, correcting deviation values, smoothing the sampling curve, etc. At the same time, the processor can also combine the sampling time window and the volume change of the liquid in the transport channel to realize the instantaneous deposition rate ( L / s) to further reflect the uniformity of pesticide application.

[0123] In actual applications, this calculation mechanism can be applied to a variety of aerial spraying operation modes, including helicopter pod spraying, fixed-wing UAV downward spraying and other scenarios. The system can dynamically adjust the sampling frequency and integration time according to different flight parameters and nozzle types to match the spraying rate.

[0124] The device for measuring the deposition amount and particle size spectrum of aerial pesticide droplets provided by the present invention calculates the deposition amount by adopting a volume integral formula. It can realize real-time, automatic and accurate estimation of the total deposition volume of droplets without relying on image acquisition and manual recognition, thereby improving the quantitative ability, data availability and on-site operation efficiency of the measurement system, and providing solid data support for the accuracy and dosage control of agricultural pesticide application.

[0125] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0126] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application, characterized in that: include: A droplet collector, the droplet collector being used to receive settled droplets during the application process and mix the droplets with a dielectric carrier liquid to form an oil-based mixture; the dielectric carrier liquid is immiscible with the droplets and has different dielectric constants; A coplanar electrode capacitance sensing module, comprising a passivation insulating layer and an electrode cover, wherein the passivation insulating layer and the electrode cover cooperate to form a droplet transport channel that penetrates the coplanar electrode capacitance sensing module, wherein a coplanar electrode composed of at least two electrodes is embedded in the passivation insulating layer; an inlet of the droplet transport channel is connected to an outlet of the droplet collector; a microfluidic control pump, the microfluidic control pump being used to control the flow rate of the oil-based mixture flowing through the droplet transport channel; A processor is used to determine the deposition amount and particle size spectrum of the droplets based on the capacitance signal generated by the coplanar electrode during the process of the oil-based mixture flowing through the droplet transport channel.

2. The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application according to claim 1, characterized in that: The coplanar electrode capacitance sensing module further includes a glass carrier layer; The carrier glass layer covers the outer side of the passivation insulating layer away from the droplet transport channel.

3. The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application according to claim 1, characterized in that: A channel contraction region is provided in the droplet transport channel, and a channel width of the channel contraction region is greater than a diameter of the droplets.

4. The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application according to claim 1, characterized in that: The droplet transport channel has multiple curved sections.

5. The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application according to claim 1, characterized in that: A piezoelectric vibrator is installed on the electrode cover at the entrance of the droplet transport channel, and the piezoelectric vibrator vibrates sinusoidally within a preset frequency range.

6. The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application according to claim 1, characterized in that: The droplet collector comprises: a dielectric carrier liquid supply device, wherein the dielectric carrier liquid supply device is loaded with dielectric carrier liquid; A mist droplet receiving tray is connected to the dielectric carrier liquid supply device and is used to receive the mist droplets settled during the application process.

7. The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application according to claim 1, characterized in that: The thickness of the passivation insulating layer is no more than 2 microns.

8. The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application according to claim 1, characterized in that: Also included is a sump; The inlet of the liquid collecting tank is connected to the outlet of the droplet transport channel through the micro-flow control pump.

9. The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application according to claim 1, characterized in that: The dielectric carrier fluid is silicone oil.

10. The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application according to any one of claims 1 to 9, characterized in that: The processor is configured to determine the deposition amount and particle size spectrum of the droplets based on the capacitance signal generated by the coplanar electrode during the process of the oil-based mixture flowing through the droplet transport channel, specifically including: determining each capacitance peak in the capacitance signal; determining the number of the droplets received and settled by the droplet collector according to the number of the capacitance peaks; Inputting each of the capacitance peak values into a droplet size decision model to obtain a droplet size corresponding to each droplet output by the droplet size decision model; Calculating the deposition amount received by the droplet collector during the application process according to the droplet particle size of each droplet; Determining the particle size spectrum of the droplets received by the droplet collector during the application process according to the distribution of the droplet particle sizes of all the droplets; The droplet size decision model is obtained by training based on historical droplet samples and droplet size labels corresponding to each historical droplet sample.

11. The device for measuring the amount of droplet deposition and particle size spectrum of aerial pesticide application according to claim 10, characterized in that: The processor calculates the deposition amount received by the droplet collector during the application process according to the droplet particle size of each droplet using the following specific calculation formula: ； in, Q is the deposition amount, n is the number of droplets, D i For the i The diameter of the droplets.

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