A sprayer control method and system for forest pest control

Abstract

The present application relates to the technical field of plant protection spraying, and specifically to a sprayer control method and system for forest pest control, the method comprising: installing a wind speed and direction sensor on the sprayer to obtain the wind speed and wind direction at each moment, determining the spraying influence stability at each moment based on the difference between the wind speeds of all adjacent moments in the multiple moments before each moment, and combining the difference between the wind speeds of the first moment and the last moment in the multiple moments; obtaining a trend sequence, determining the forest wind speed trend at each moment according to the overall level of the difference between all adjacent elements in the trend sequence and the overall level of the difference between all adjacent elements after the last extreme point of the trend sequence, and then obtaining the wind speed correction value at each moment, calculating the rotation angle of the sprayer nozzle at each moment, so as to control the rotation angle of the sprayer nozzle. The present application adaptively adjusts the spraying according to the changes in wind speed and direction, and improves the spraying efficiency for forest pest control.

Description

Technical Field

[0001] The present application relates to the technical field of plant protection spraying, and in particular to a sprayer control method and system for forest pest control. Background Art

[0002] Forest pests are harmful insects that affect the health of trees. They eat the leaves, buds and other parts of plants, which not only hinders the normal growth of plants, but also may cause a serious decline in yield and quality, and even cause the death of trees, thereby destroying the ecological balance of the forest. Sprayers are a highly efficient pesticide application equipment that disperses liquid into fine droplets and is widely used in the prevention and control of pests and diseases in forestry and agriculture. They can effectively cover the pesticides to various parts of the plants, improve the prevention and control effect, and protect trees from pests.

[0003] Due to the different heights of trees in the forest, traditional technology generally adjusts the angle of the sprayer nozzle to spray pest control drugs on the trees. However, since there is often natural wind in the forest, the natural wind will affect the spray mist of the sprayer, so that the drug cannot fall to the intended location, resulting in poor insect control effect in this part.

[0004] When controlling pests and diseases in forests, due to the different heights of trees, traditional spraying technology usually requires adjusting the nozzle angle to ensure that the drug can cover the tree crowns at different heights. However, the forest environment is often accompanied by natural wind, which can significantly affect the drift and deposition of the spray mist sprayed by the sprayer. Changes in wind speed and direction can cause droplets to deviate from the predetermined spraying path, causing the spray mist sprayed by the sprayer to drift and deposit, resulting in low drug coverage in the target area and poor pest control effects. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of this application is to provide a sprayer control method and system for forest pest control. The technical solutions adopted are as follows:

[0006] The present application provides a method for controlling a sprayer for forest pest control, comprising the following steps:

[0007] Install wind speed and direction sensors on the sprayer to obtain wind speed and direction at each moment. The wind speeds at multiple moments before each moment form a forest wind speed sequence. The wind direction angle at each moment is determined by combining the wind direction and the sprayer's forward direction.

[0008] Determine the unevenness of spray impact at each moment based on the difference between the wind speeds at all adjacent moments in the forest wind speed sequence at each moment; determine the wind speed impact rate at each moment based on the difference between the wind speeds at the first moment and the last moment in the forest wind speed sequence; determine the stability of spray impact at each moment by combining the unevenness of spray impact and the wind speed impact rate;

[0009] The forest wind speed series is decomposed into a time series to obtain a trend series. The forest wind speed trend at each moment is determined based on the overall level of the difference between all adjacent elements in the trend series and the overall level of the difference between all adjacent elements after the last extreme point of the trend series.

[0010] Obtain the wind speed correction value at each moment according to the spray impact stability at each moment and the forest wind speed trend;

[0011] According to the wind direction angle at each moment, the sprayer moving speed, the sprayer spray outlet speed and the angle between the nozzle and the forward direction of the spray, the rotation angle of the sprayer nozzle at each moment is calculated in combination with the wind speed correction value, and the rotation angle of the sprayer nozzle is controlled by a PID controller.

[0012] Preferably, the wind direction angle at each moment is the angle between the wind direction at each moment and the forward direction of the sprayer.

[0013] Preferably, the spray impact unevenness at each moment is the average value of the differences between wind speeds at all adjacent moments in the forest wind speed sequence at each moment.

[0014] Preferably, the wind speed influence rate at each moment is calculated as follows: , where Indicates the wind speed impact rate at the current moment; , They respectively represent the nth and first elements in the forest wind speed sequence at the current moment.

[0015] Preferably, the calculation formula for the spray impact stability at each moment is: , where DG represents the spray impact stability at the current moment; , CG represent the current spray impact unevenness and wind speed impact rate respectively; exp() represents an exponential function with a natural constant as the base; Represents a value that avoids zero denominator.

[0016] Preferably, the calculation formula for the forest wind speed trend at each moment is:

[0017] , where EG represents the forest wind speed trend at the current moment; m represents the number of elements in the trend sequence; , represents the jth and j-1th values ​​in the trend sequence; N represents the number of elements in the trend representation sequence; , Represents the kth and k-1th elements in the trend characterization sequence, where the trend characterization sequence is obtained by dividing the elements of the trend sequence through the extreme points of the trend sequence.

[0018] Preferably, all elements after the last extreme point in the trend sequence are selected to form a trend characterization sequence.

[0019] Preferably, the wind speed correction value at each moment is expressed as: , where v represents the wind speed correction value of the current wind speed; V represents the wind speed at the current moment; sgn represents the sign function; DG and EG represent the spray influence stability and forest wind speed trend at the current moment, respectively.

[0020] Preferably, the calculation process corresponding to the rotation angle of the spray nozzle at each moment is:

[0021] ; In the formula, Indicates the current rotation angle of the sprayer nozzle; Indicates the wind direction angle at the current moment; represents the cosine function; is the inverse tangent function; v represents the wind speed correction value of the current wind speed; dv and bv represent the moving speed of the sprayer and the outlet speed of the sprayer spray at the current moment; Indicates the angle between the sprayer nozzle and the forward direction at the current moment.

[0022] An embodiment of the present application also provides a sprayer control system for forest pest control, the system comprising a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor implements the steps of any one of the above methods when executing the computer program.

[0023] From the above, it can be seen that the sprayer control method and system for forest pest control provided by the present application have at least the following beneficial effects:

[0024] This application significantly improves the efficiency and effectiveness of forest pest control by precisely controlling the sprayer to cope with the influence of natural wind in the forest. Compared with traditional technology, the medicine is directly sprayed on forest trees. Due to the existence of natural wind in the forest, the natural wind will cause drift and deposition of the medicine mist sprayed by the sprayer, which often results in the failure of the medicine mist to accurately cover the target area, resulting in waste of resources and poor control effect. This application analyzes the numerical value of the wind speed in the forest, and realizes the correction of the wind speed in the forest at the current moment through the change state and change trend of the wind speed. By correcting the wind speed value, the angle of the sprayer nozzle is dynamically adjusted to ensure that the medicine mist can be adaptively sprayed according to the changes in wind speed and direction, effectively avoiding the drift and deposition problems of the medicine mist, thereby improving the control effect of forest pests. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A flowchart of the steps of a sprayer control method for forest pest control provided in this application. DETAILED DESCRIPTION

[0027] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of the sprayer control method and system for forest pest control proposed in the present application, its specific implementation, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0028] Unless otherwise specified and limited, terms such as "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a circuit structure, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such articles or devices. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the article or device including the element. In addition, the term "and\or" used herein includes any and all combinations of one or more related listed items. All technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application.

[0029] The following is a detailed description of a specific solution of a sprayer control method and system for forest pest control provided by the present application in conjunction with the accompanying drawings.

[0030] See also Figure 1 , which shows a flow chart of a sprayer control method for forest pest control provided by an embodiment of the present application, comprising the following steps:

[0031] Step 1: Install a wind speed and direction sensor on the sprayer to obtain the wind speed and direction at each moment. The wind speeds at multiple moments before each moment constitute the forest wind speed sequence, and the angle between the wind direction and the sprayer's forward direction is taken as the wind direction angle.

[0032] First, a wind speed and direction sensor is installed at the tail of the sprayer to collect wind speed and direction data of the environment during the spraying process. The sampling frequency of the sensor is 10 Hz. Furthermore, in this embodiment, the angle between the wind direction at each moment and the forward direction of the sprayer is used as the wind direction angle at each moment. The time interval for data collection in this embodiment is 0.1 s.

[0033] Furthermore, in order to analyze the wind speed data at each moment, the wind speeds at multiple moments before each moment are combined into a forest wind speed sequence at each moment. In this embodiment, the wind speeds 100 moments before each moment are combined into a forest wind speed sequence at each moment. In this embodiment, during the process of collecting wind speed data, due to the complex environment in the forest, the wind speed data collected by the wind speed and wind direction sensor has noise. Therefore, in this embodiment, mean filtering is used to filter the collected wind speed data, and the filtered data are arranged in the order of collection time to obtain a forest wind speed sequence.

[0034] Step 2: Determine the spray impact unevenness at each moment based on the difference between the wind speeds at all adjacent moments in the forest wind speed sequence at each moment; determine the wind speed impact rate at each moment based on the difference between the wind speeds at the first moment and the last moment in the forest wind speed sequence; determine the spray impact stability at each moment by combining the spray impact unevenness and the wind speed impact rate.

[0035] Fluctuations in wind speed and direction are crucial to the spraying operation of insecticide sprayers, as they directly affect the flight trajectory and deposition location of droplets. Under the influence of wind, droplets may deviate from the target area, reducing the efficacy of the drug. At the same time, strong winds may also blow droplets to non-target areas, which not only reduces the control effect, but also may pollute the environment and increase the risk to non-target organisms.

[0036] Since different wind speeds have different effects on droplets, the more stable the wind speed in the environment over a period of time, the more stable the effect of wind speed on droplets; at the same time, if the wind speed changes more, the effect of wind speed on droplets will be different at different times.

[0037] Taking the current moment as an example, the spray impact unevenness at the current moment is calculated based on the difference between the wind speeds at all adjacent moments in the forest wind speed sequence at the current moment, wherein the spray impact unevenness at each moment is the average value of the difference between the wind speeds at all adjacent moments in the forest wind speed sequence at each moment. For ease of understanding, the corresponding expression in this embodiment is as follows:

[0038] , where represents the unevenness of the spray impact at the current moment; n represents the number of elements in the forest wind speed sequence at the current moment, that is, the number of moments; , They represent the i-th and i-1-th elements in the forest wind speed sequence at the current moment respectively; Indicates the absolute value sign.

[0039] When the forest insect sprayer is spraying, if the wind speed in the environment changes more with time, the droplets sprayed by the sprayer will be affected by the wind speed and the change will not be stable. Therefore, the greater the wind speed change, the greater the absolute value of the wind speed difference at adjacent moments. The larger the value, the greater the value of the spray impact unevenness YG of the forest wind speed sequence. At this time, the nozzle angle of the sprayer should also be adjusted so that the spray spray can be evenly sprinkled on the trees to better prevent and control forest pests.

[0040] When the wind speed in the forest changes steadily, that is, the wind acceleration is constant, the adjustment of the sprayer nozzle angle should also be carried out smoothly to ensure that the drug effectively covers the target area, thereby reducing drug drift, improving the prevention and control effect, and reducing the potential impact on the environment.

[0041] Further, according to the difference between the wind speed at the first moment and the wind speed at the last moment in the forest wind speed sequence at the current moment, the influence rate of the wind speed in the forest wind speed sequence at the current moment on the wind speed of the sprayer droplets is analyzed. Specifically, the calculation formula in this embodiment is:

[0042] , where Indicates the wind speed impact rate at the current moment; , They respectively represent the nth and first elements in the forest wind speed sequence at the current moment.

[0043] The greater the overall change in wind speed in the forest over a period of time, the greater the impact of wind speed on the spray droplets of the sprayer, and the greater the adjustment angle of the sprayer nozzle should be. The larger it is, the greater the value of CG, the wind speed influence rate on the sprayer droplets.

[0044] Furthermore, based on the spray impact unevenness of the forest wind speed sequence at the current moment and the wind speed impact rate of the wind speed on the spray droplets of the sprayer, the spray impact stability of the wind speed at the current moment on the sprayer spray is constructed.

[0045] , where DG represents the spray impact stability at the current moment; exp() represents an exponential function with a natural constant as the base; Indicates the unevenness of the spray impact; Indicates the wind speed influence rate; Indicates a value that avoids the denominator being zero, and in this embodiment, the value is 1.

[0046] The greater the volatility of wind speed in the forest, the greater the impact of wind speed on the spray effect of the sprayer, and the greater the fluctuation in the state of the spray from the sprayer nozzle. Therefore, the greater the value of the spray influence unevenness YG, the smaller the difference between the initial wind speed and the final wind speed, indicating that the overall convergence of the wind speed is higher, so the wind speed influence rate CG of the sprayer droplets is smaller. Therefore, the forest wind speed sequence as a whole presents a state of large volatility but good convergence. In this case, the wind speed has a more unstable impact on the sprayer spray, so the spray influence stability DG is smaller.

[0047] Step 3: Decompose the forest wind speed sequence into a time series to obtain a trend sequence. Determine the forest wind speed trend at each moment based on the overall level of the difference between all adjacent elements in the trend sequence and the overall level of the difference between all adjacent elements after the last extreme point of the trend sequence.

[0048] Furthermore, since the wind speed in the forest is constantly changing, it will show a trend, such as rising or falling. When the wind speed has an upward trend, the measured wind speed should be compensated for by value, and when the wind speed has a downward trend, the wind speed should be compensated for by value reduction, so as to ensure the accurate measurement of the measured wind speed.

[0049] Therefore, the forest wind speed series is used as the input of the STL (Seasonal and Trend decomposition using Loess) decomposition algorithm, and the output is the trend, season, and residual of the forest wind speed series. The extracted trend part is recorded as the trend series. The STL decomposition algorithm is a well-known technology, and the specific calculation process will not be repeated here.

[0050] Since the trend closer to the current moment has a greater impact on the wind speed in the forest, this is because the recent trend can better reflect the current environmental conditions and short-term climate patterns, the data has high timeliness, and can more accurately predict and reflect the current wind speed changes. Therefore, the trend sequence is used as the input of the extreme point detection algorithm, and the output is the extreme point of the trend sequence. All elements after the last extreme point in the trend sequence are selected to form a trend representation sequence. The extreme point detection algorithm is a well-known technology, and the specific calculation process will not be repeated.

[0051] The forest wind speed trend is calculated based on the overall level of the difference between all adjacent elements in the trend sequence and the overall level of the difference between all adjacent elements after the last extreme point of the trend sequence.

[0052] , where EG represents the forest wind speed trend at the current moment; m represents the number of elements in the trend sequence; , represents the jth and j-1th values ​​in the trend sequence; N represents the number of elements in the trend representation sequence; , Represents the kth and k-1th elements in the trend representation sequence.

[0053] When the wind speed trend in the forest has a certain fluctuation, as long as the trend of wind speed increase is greater than the trend of wind speed decrease, the wind speed in the forest will have an upward trend as a whole, so the sum of the differences of adjacent elements of the trend sequence is The larger the value, the smaller the trend is. On the contrary, the smaller the trend is, the greater the trend is. Then the sum of the differences between adjacent elements of the trend sequence is The smaller the wind speed trend is, the smaller the trend is. Since the recent wind speed trend can better reflect the current environmental conditions and short-term climate patterns, when the recent wind speed change trend is a downward trend, the sum of the differences between adjacent elements in the trend representation sequence is The larger the value of , the greater the trend of the forest wind speed sequence.

[0054] When the forest wind speed trend of the forest wind speed sequence is positive, it means that the wind speed in the forest has an overall upward trend. When adjusting the wind speed at the current moment, the trend of the wind speed should be corrected to increase. When EG is negative, it means that the wind speed in the forest is on a downward trend, and the wind speed should be corrected to decrease.

[0055] Step 4: Obtain the wind speed correction value at each moment based on the spray impact stability at each moment and the forest wind speed trend.

[0056] Further, in this embodiment, according to the above process, the spray influence stability of the wind speed in the forest wind speed sequence at each moment on the spray can be obtained, and the wind speed change trend can be analyzed. Thus, the wind speed at each moment can be corrected by combining the wind speed at each moment with the spray influence stability and the forest wind speed trend, and the wind speed correction value at each moment is calculated. In this embodiment, the calculation formula is:

[0057] , where v represents the wind speed correction value of the current wind speed; V represents the wind speed at the current moment; EG represents the forest wind speed trend at the current moment; sgn represents the sign function; Indicates the spray impact stability at the current moment.

[0058] The greater the stability of the wind speed in the forest on the spray of the sprayer, the smaller the volatility of the wind speed in the forest before the current moment, and the effect of the wind speed in the forest on the spray of the sprayer is relatively stable. When the forest wind speed trend of the forest wind speed sequence is positive, it means that the wind speed in the forest is fluctuating in the direction of increase, and the value of EG is negative, and the wind speed is fluctuating in the direction of decrease. When it fluctuates in the direction of increase, As the value of increases, the wind speed correction value v becomes larger, and vice versa.

[0059] Step 5: According to the wind direction angle at each moment, the sprayer moving speed, the sprayer spray outlet speed and the angle between the nozzle and the forward direction of the spray, the rotation angle of the sprayer nozzle at each moment is calculated in combination with the wind speed correction value, and the rotation angle of the sprayer nozzle is controlled by a PID controller.

[0060] For the forest wind speed correction value obtained in the above steps, the greater the forest wind speed correction value, the greater the impact on the spraying of the sprayer, and thus the greater the impact on the angle between the sprayer nozzle and the sprayer's forward direction. The moving speed dv of the sprayer, the outlet speed bv of the sprayer, and the wind direction angle at the current moment , calculate the rotation angle of the sprayer nozzle , the expression is:

[0061]

[0062] In the formula, Indicates the current rotation angle of the sprayer nozzle; Indicates the wind speed correction value at the current moment; Indicates the wind direction angle at the current moment; represents the cosine function; is the inverse tangent function; dv represents the moving speed of the sprayer at the current moment, and bv represents the outlet speed of the sprayer at the current moment; Indicates the angle between the sprayer nozzle and the forward direction at the current moment.

[0063] Further, the calculated rotation angle of the sprayer nozzle , transmitted to the sprayer rotation angle control module. In this embodiment, the sprayer rotation angle control module is a PID controller. The PID controller adjusts the angle of the sprayer nozzle through feedback results. It should be noted that the specific control process of the PID controller is a well-known prior art to those skilled in the art and will not be elaborated in detail in this embodiment. The adjusted sprayer can accurately and evenly spray the atomized insect repellent mist at various positions of the trees in the forest. This embodiment can not only improve the forest's pest control effect, but also reduce the pollution caused by insect repellent drugs to the environment.

[0064] Based on the same inventive concept as the above method, an embodiment of the present application also provides a sprayer control system for forest pest control, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of any one of the above-mentioned sprayer control methods for forest pest control are implemented.

[0065] It is to be understood that the sequence of the embodiments of the present application described above is for description only and does not represent the advantages and disadvantages of the embodiments. The above describes specific embodiments of the present specification. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0066] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0067] The above content is only an implementation method of the present application and is not intended to limit the scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the protection scope of the present application.

Claims

1. A method for controlling a sprayer for forest pest control, characterized in that: The following steps are involved: Install wind speed and direction sensors on the sprayer to obtain wind speed and direction at each moment. The wind speeds at multiple moments before each moment form a forest wind speed sequence. The wind direction angle at each moment is determined by combining the wind direction and the sprayer's forward direction. Determine the unevenness of spray impact at each moment based on the difference between the wind speeds at all adjacent moments in the forest wind speed sequence at each moment; determine the wind speed impact rate at each moment based on the difference between the wind speeds at the first moment and the last moment in the forest wind speed sequence; determine the stability of spray impact at each moment by combining the unevenness of spray impact and the wind speed impact rate; The forest wind speed series is decomposed into a time series to obtain a trend series. The forest wind speed trend at each moment is determined based on the overall level of the difference between all adjacent elements in the trend series and the overall level of the difference between all adjacent elements after the last extreme point of the trend series. Obtain the wind speed correction value at each moment according to the spray impact stability at each moment and the forest wind speed trend; According to the wind direction angle at each moment, the movement speed of the sprayer, the spray outlet speed of the sprayer, and the angle between the nozzle and the forward direction of the spray, the rotation angle of the sprayer nozzle at each moment is calculated in combination with the wind speed correction value, and the rotation angle of the sprayer nozzle is controlled by a PID controller; The spray impact unevenness at each moment is the average value of the difference between the wind speeds at all adjacent moments in the forest wind speed sequence at each moment; The calculation formula of the wind speed influence rate at each moment is: , where Indicates the wind speed impact rate at the current moment; , They represent the nth and first elements in the forest wind speed sequence at the current moment respectively; The calculation formula for the spray influence stability at each moment is: , where DG represents the spray impact stability at the current moment; , CG represent the current spray impact unevenness and wind speed impact rate respectively; exp() represents an exponential function with a natural constant as the base; Indicates a value that avoids a denominator of zero; The calculation formula of the forest wind speed trend at each moment is: , where EG represents the forest wind speed trend at the current moment; m represents the number of elements in the trend sequence; , Represents the jth and j-1th values ​​in the trend sequence; N represents the number of elements in the trend representation sequence; , represents the kth and k-1th elements in the trend characterization sequence, where the trend characterization sequence is obtained by dividing the elements of the trend sequence by the extreme points of the trend sequence; Select all elements after the last extreme point in the trend sequence to form a trend representation sequence; The wind speed correction value expression at each moment is: , where v represents the wind speed correction value of the current wind speed; V represents the wind speed at the current moment; sgn represents the sign function; DG and EG represent the spray impact stability and forest wind speed trend at the current moment, respectively; The calculation process corresponding to the rotation angle of the spray nozzle of the sprayer at each moment is: ; In the formula, Indicates the current rotation angle of the sprayer nozzle; Indicates the wind direction angle at the current moment; represents the cosine function; is the inverse tangent function; v represents the wind speed correction value of the current wind speed; dv and bv represent the moving speed of the sprayer and the outlet speed of the sprayer spray at the current moment; Indicates the angle between the sprayer nozzle and the forward direction at the current moment.

2. A sprayer control method for forest pest control as claimed in claim 1, characterized in that: The wind direction angle at each moment is the angle between the wind direction at each moment and the forward direction of the sprayer.

3. A sprayer control system for forest pest control, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 2 are implemented.

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