One-driving-two water and fertilizer irrigation pressure adjusting method and device based on sensor network

Abstract

The invention provides a one-driving-two water and fertilizer irrigation pressure adjusting method and device based on a sensor network, relates to the technical field of irrigation pressure adjustment, and achieves the effect of improving the accuracy and resource utilization efficiency of an irrigation system through differential modeling and a dynamic adjustment strategy. The laminar flow model and the turbulent flow model are adopted for the main pipeline and the branch pipelines respectively, and an error correction mechanism is combined, so that high precision of pressure and flow velocity calculation in the pipelines is ensured; by means of a multiple regression model, the soil temperature and humidity, the nozzle pressure and the valve opening degree are dynamically associated, and uniformity and intelligent regulation and control of global irrigation are achieved; and finally, through real-time acquisition of soil parameters and optimization of nozzle flow distribution, water and fertilizer waste is reduced, and it is ensured that the soil environment is maintained in an ideal state. Compared with the prior art, the scheme not only improves the irrigation efficiency, but also is suitable for different soil and crop environments, and provides an intelligent, efficient and water-saving solution for a large agricultural irrigation system.

Description

Technical Field

[0001] The present invention relates to the technical field of irrigation pressure regulating methods, and in particular to a one-to-two water-fertilizer irrigation pressure regulating method and device based on a sensor network. Background Art

[0002] In modern agricultural irrigation systems, how to accurately control the distribution of water and fertilizer to meet the needs of crop growth has always been a key technical issue. In the prior art, many irrigation systems have simplified the modeling of pressure and flow rate of the main and branch pipes, failing to take into account the impact of different pipes on the pressure and flow rate of the fluid, and especially ignoring the significant impact of pipe bending on flow rate and pressure distribution, resulting in frequent uneven irrigation. At the same time, for the relationship between flow rate at the sprinkler and soil temperature and humidity, traditional methods often use static or single variable control, lacking the ability to model the dynamic relationship between soil temperature and humidity, actual pressure and the opening and closing degree of sprinkler valves, and are difficult to adapt to complex and changeable irrigation environments. In addition, for real-time data collection in each irrigation area and dynamic adjustment of valves, most systems fail to form a complete closed-loop control, resulting in waste of water resources and low irrigation efficiency, especially in large-scale irrigation systems with multi-branch pipe networks.

[0003] In the prior art, the publication number CN105432431B discloses an irrigation control method and device: after the first flow control component and the first pressure gauge are set at the irrigation water source, the crop to be irrigated is irrigated; the water content in the soil of the crop to be irrigated is detected by the water content detection component, if the water content is inconsistent with the preset water content threshold, the flow is adjusted by the first flow control component until the detection result shows that the water content is consistent with the preset water content threshold, and the corresponding flow is used as the current optimal irrigation flow; the current system pressure value is obtained by the first pressure gauge as the optimal irrigation pressure, and the optimal irrigation flow and the optimal irrigation pressure are maintained to irrigate the crop to be irrigated, so as to ensure that the moisture condition in the soil of the crop to be irrigated is in the optimal state. Although it can reversely adjust the irrigation pressure according to the water content in the soil to improve the irrigation efficiency, it does not take into account the influence of the installation height, diameter, bending and other parameters between different pipes on the internal fluid, nor does it take into account the influence of soil temperature on water evaporation, so that its control accuracy is insufficient and its applicability is low.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0005] The purpose of the present invention is to provide a one-to-two water-fertilizer irrigation pressure regulation method and device based on a sensor network to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions: A one-to-two water-fertilizer irrigation pressure regulation method based on a sensor network, characterized in that the specific steps include: S1: Collect the hydraulic parameters and pipeline parameters of the main pipeline and branch pipeline in the irrigation system, and build the pressure distribution models in the main pipeline and branch pipeline respectively based on the Bernoulli equation; S2: Generate corresponding pressure distributions based on the pressure distribution models of the main pipeline and the branch pipeline, obtain the actual pressures of the key points in the main pipeline and each nozzle on the branch pipeline, and adjust the hydraulic parameters based on the actual pressures of the key points in the main pipeline; S3: Collect the soil temperature and humidity of the irrigation area corresponding to each sprinkler, generate a relationship model between the soil temperature and humidity, the actual pressure and the nozzle valve opening and closing degree, and adjust the nozzle valve opening and closing degree based on the ideal soil temperature and humidity.

[0007] Preferably, the hydraulic parameters include the total flow of the irrigation system, the initial pump pressure and initial flow rate at the inlet of the main pipeline, and the measured pressure and measured flow rate at the connection between the main pipeline and the branch pipeline and at the outlet of the branch pipeline; The pipeline parameters include the pipeline length, pipeline diameter, pipeline thickness, friction coefficient, and bending coefficient of the main pipeline and the branch pipeline.

[0008] Preferably, the logic for constructing the pressure distribution model in the main pipeline and the branch pipeline is: Taking the height of the main pipeline inlet as the reference height, the relationship model between the ideal pressure, flow velocity and height difference in the main pipeline and branch pipeline is constructed based on the Bernoulli equation, which is expressed as: ; ; in represents the ideal pressure at the 𝑖th critical point in the main pipeline, Indicates the branch pipe The ideal pressure at each nozzle, subscript represents the index of the key point, , is the number of key points, Indicates the index of the sprinkler head. , is the number of nozzles, represents the density of the fluid in the irrigation system, represents the flow velocity at the 𝑖th key point in the main pipe, Indicates the branch pipe The flow rate at each nozzle, represents the acceleration due to gravity, represents the height difference between the 𝑖th key point in the main pipeline and the reference height, Indicates the branch pipe The height difference between the nozzle and the reference height, represents the equation constant, where the equation constant is calculated as: ; in , represent the initial pump pressure and initial flow rate at the main pipeline inlet respectively; Then calculate the pressure loss in the main pipeline and branch pipeline, the calculation method is: ; ; In the formula , Respectively represent the pressure loss in the main pipeline and branch pipeline, , Represent the friction coefficients of the main pipeline and branch pipeline respectively, , Respectively represent the pipeline lengths of the main pipeline and branch pipeline, , Respectively represent the pipe diameters of the main pipe and branch pipe; The actual pressure in the main pipeline and branch pipeline is expressed as: ; ; In the formula represents the actual pressure at the 𝑖th key point in the main pipeline, Indicates the branch pipe The actual pressure at each nozzle.

[0009] Preferably, the key points in the main pipeline include the bending points of the main pipeline and the connection points between the main pipeline and the branch pipeline. The logic for adjusting the hydraulic parameters based on the actual pressure of the key points in the main pipeline is: Calculate the actual pressure of each key point in the main pipeline respectively, compare the actual pressure at the connection between the main pipeline and the branch pipeline with the measured pressure at the inlet of the branch pipeline in the hydraulic parameters, and generate the corresponding error coefficient. The calculation method is: ; In the formula , Respectively represent the actual pressure at the connection between the main pipeline and the two branch pipelines, , Respectively represent the measured pressure at the connection between the main pipeline and the two branch pipelines; Then the actual pressure of the key point is corrected using the error coefficient. The corrected actual pressure is expressed as: ; By adjusting the initial pump pressure at the main pipeline inlet, the actual pressure at each key point after correction meets , the adjustment is considered complete, where Indicates the preset minimum pressure. Indicates the pressure threshold of the main pipeline and branch pipeline, represents the coefficient of volatility, and .

[0010] Preferably, the flow velocity calculation methods at different positions in the main pipeline and the branch pipeline are respectively: ; ; In the formula represents the total flow of the irrigation system, , denote the 𝑖th key point and the The distance between each nozzle and the center of the pipe, Indicates the bending coefficient of the pipe. Indicates the pipe thickness of the branch pipe.

[0011] Preferably, the logic for generating the relationship model between the soil temperature and humidity, the actual pressure and the valve opening degree of the sprinkler corresponding to the sprinkler is: First, the ideal pressure at the nozzle is corrected based on the error coefficient. The calculation method is: ; Then, the corrected ideal pressure at the sprinkler head, the nozzle valve opening and closing degree, and soil temperature are taken as independent variables, and soil moisture is taken as the dependent variable. A multivariate regression model is constructed as the relationship model between soil temperature and humidity, actual pressure, and nozzle valve opening and closing degree. The model is expressed as follows: ; In the formula are model parameters, , Respectively represent The soil moisture and soil temperature of the irrigation area corresponding to each sprinkler head, Indicates The opening and closing degree of the valve of each nozzle.

[0012] Preferably, the logic for adjusting the opening and closing degree of the nozzle valve is: Calculate the flow rate at each nozzle in the branch pipe, and then calculate the actual pressure at each nozzle; Substitute ideal soil moisture, soil temperature, and actual pressure into the multiple regression model; The multivariate regression model is solved to obtain the optimal valve opening and closing degree of each nozzle and make adjustments.

[0013] A one-to-two water-fertilizer irrigation pressure regulating device based on a sensor network, wherein the one-to-two water-fertilizer irrigation pressure regulating device based on a sensor network is used to execute the one-to-two water-fertilizer irrigation pressure regulating method based on a sensor network, specifically comprising: A hydraulic sensing module, which is used to collect the total flow of the irrigation system, the initial pump pressure and initial flow rate at the inlet of the main pipeline, and the measured pressure and flow rate at the connection between the main pipeline and the branch pipeline and at the outlet of the branch pipeline; A temperature and humidity sensing module, wherein the temperature and humidity sensing module includes a plurality of groups of temperature sensors and humidity sensors, which are arranged at the center of the irrigation area corresponding to the sprinkler head and are used to detect the soil temperature and soil humidity of the irrigation area; A model building module, wherein the model building module is used to respectively build pressure distribution models in the main pipeline and the branch pipeline; A data analysis module, the data analysis module is used to generate a relationship model between soil temperature and humidity, actual pressure and the opening and closing degree of the sprinkler valve, and generate a control instruction for the sprinkler valve based on the ideal soil temperature and humidity; A valve control module, wherein the valve control module is used to adjust the opening and closing degree of the valve of the nozzle according to the control instruction.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention solves the problems of inaccurate pressure calculation, uneven velocity distribution and imprecise irrigation control in the existing irrigation system through differentiated modeling and dynamic adjustment strategies, which improves the accuracy of the irrigation system and the efficiency of resource utilization. By adopting laminar flow and turbulent flow models for the main pipeline and branch pipeline respectively, combined with the error correction mechanism, the high accuracy of the pressure and velocity calculation in the pipeline is ensured; with the help of a multivariate regression model, the soil temperature and humidity, nozzle pressure and valve opening are dynamically associated to achieve uniformity and intelligent control of global irrigation; finally, by real-time collection of soil parameters and optimization of nozzle flow distribution, water and fertilizer waste is greatly reduced, ensuring that the soil environment is maintained in an ideal state. Compared with traditional technologies, this solution not only improves irrigation efficiency, but is also suitable for different soil and crop environments, providing an intelligent, efficient and water-saving solution for large-scale agricultural irrigation systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall method flow of the present invention; Figure 2 It is a schematic diagram of the module structure of the present invention. DETAILED DESCRIPTION

[0016] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0017] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0018] Example: See also Figure 1~Figure 2 , the present invention provides a technical solution: A one-to-two water-fertilizer irrigation pressure regulation method based on a sensor network, the specific steps comprising: S1: Collect hydraulic parameters and pipeline parameters of the main pipeline and branch pipeline in the irrigation system, and build pressure distribution models in the main pipeline and branch pipeline based on the Bernoulli equation. The hydraulic parameters include the total flow of the irrigation system, the initial pump pressure and initial flow rate at the inlet of the main pipeline, the measured pressure and measured flow rate at the connection between the main pipeline and the branch pipeline and the outlet of the branch pipeline. The pipeline parameters include the pipeline length, pipeline diameter, pipeline thickness, friction coefficient, and bending coefficient of the main pipeline and branch pipeline.

[0019] The logic for constructing the pressure distribution model in the main pipeline and branch pipeline is: Taking the height of the main pipeline inlet as the reference height, the relationship model between the ideal pressure, flow velocity and height difference in the main pipeline and branch pipeline is constructed based on the Bernoulli equation, which is expressed as: ; ; in represents the ideal pressure at the 𝑖th critical point in the main pipeline, Indicates the branch pipe The ideal pressure at each nozzle, subscript represents the index of the key point, , is the number of key points, Indicates the index of the sprinkler head. , is the number of nozzles, represents the density of the fluid in the irrigation system, represents the flow velocity at the 𝑖th key point in the main pipe, Indicates the branch pipe The flow rate at each nozzle, represents the acceleration due to gravity, represents the height difference between the 𝑖th key point in the main pipeline and the reference height, Indicates the branch pipe The height difference between the nozzle and the reference height, It is understandable that the relationship model between the main pipeline and the branch pipeline is essentially the same, but because the main pipeline mainly focuses on the pressure at the bends and joints, and the branch pipeline mainly focuses on the pressure at each nozzle, the areas of concern are different, so when constructing the pressure distribution model, they are constructed separately for analysis.

[0020] The equation constant is calculated as: ; in , They represent the initial pump pressure and initial flow rate at the main pipeline inlet respectively.

[0021] The classic fluid mechanics model Bernoulli's equation is used here to accurately describe the energy conservation relationship of the fluid in the pipeline (that is, the distribution of pressure, kinetic energy and potential energy). At the same time, the pressure distribution models of the main pipeline and the branch pipeline are constructed separately, and the key points of different areas (such as bending points, connection points, and nozzle pressure) are analyzed. The logic is clear and the physical meaning is clear. It can be refined to the key points and nozzles for analysis, which can provide a more comprehensive understanding of the pressure distribution of the entire system.

[0022] Then calculate the pressure loss in the main pipeline and branch pipeline, the calculation method is: ; ; In the formula , Respectively represent the pressure loss in the main pipeline and branch pipeline, , Represent the friction coefficients of the main pipeline and branch pipeline respectively, , Respectively represent the pipeline lengths of the main pipeline and branch pipeline, , Respectively represent the pipe diameters of the main pipe and branch pipe.

[0023] The pressure loss here is calculated based on the Darcy-Weisbach formula, which reflects the pressure loss caused by the viscous friction between the fluid and the pipe wall. By introducing pressure loss, the pressure distribution can be made closer to the actual application scenario, so as to accurately capture the pressure loss caused by the pipeline characteristics in the system and provide more accurate pressure distribution results.

[0024] The actual pressure in the main pipeline and branch pipeline is expressed as: ; ; In the formula represents the actual pressure at the 𝑖th key point in the main pipeline, Indicates the branch pipe The actual pressure at each nozzle.

[0025] In this step, by collecting water parameters in real time and combining them with dynamic calculation models, the system operation status can be quickly adjusted to adapt to different irrigation needs, and resource waste or equipment damage caused by insufficient or excessive pressure can be avoided. Moreover, since the pressure distribution models of the main pipeline and branch pipeline are constructed separately and analyzed at key points and sprinklers, a more comprehensive understanding of the pressure distribution of the entire system can be achieved, so that the deviation between the actual pressure of the sprinkler and the ideal pressure is smaller. Compared with the traditional method of considering the pipeline as a whole, the calculation results are more accurate, which can effectively improve the uniformity and efficiency of irrigation.

[0026] S2: Generate corresponding pressure distributions based on the pressure distribution models of the main pipeline and the branch pipeline respectively, obtain the actual pressures of the key points in the main pipeline and each nozzle on the branch pipeline, and adjust the hydraulic parameters based on the actual pressures of the key points in the main pipeline.

[0027] The key points in the main pipeline include the bending points of the main pipeline and the connection points between the main pipeline and the branch pipeline. The logic for adjusting the hydraulic parameters based on the actual pressure of the key points in the main pipeline is: Calculate the actual pressure of each key point in the main pipeline respectively, compare the actual pressure at the connection between the main pipeline and the branch pipeline with the measured pressure at the inlet of the branch pipeline in the hydraulic parameters, and generate the corresponding error coefficient. The calculation method is: ; In the formula , Respectively represent the actual pressure at the connection between the main pipeline and the two branch pipelines, , Respectively represent the measured pressure at the connection between the main pipeline and the two branch pipelines; Then the actual pressure of the key point is corrected using the error coefficient. The corrected actual pressure is expressed as: ; By adjusting the initial pump pressure at the main pipeline inlet, the actual pressure at each key point after correction meets , the adjustment is considered complete, where Indicates the preset minimum pressure. Indicates the pressure threshold of the main pipeline and branch pipeline, represents the coefficient of volatility, and By comparing the pressure at the key points of the main pipeline with the measured values ​​at the inlet of the branch pipeline, an error coefficient is generated, and the pressure at all key points is dynamically corrected to ensure that the calculation results are closer to the actual situation.

[0028] The flow velocity calculation methods at different locations in the main pipeline and branch pipeline are: ; ; In the formula represents the total flow of the irrigation system, , denote the 𝑖th key point and the The distance between each nozzle and the center of the pipe, The bending coefficient of the pipeline can be determined by simulation or empirical estimation. Indicates the pipe thickness of the branch pipe.

[0029] The reason why the flow velocity calculation methods in the main pipeline and the branch pipeline are different here is that the main pipeline is relatively thick, the flow velocity of the internal fluid is low, and it is more similar to laminar flow. The distribution of the flow velocity in the pipeline follows the parabolic law and can be described by the Poiseuille equation; while the branch pipeline is thinner, the flow velocity of the internal fluid is higher, and it is more similar to turbulence. The distribution of the flow velocity in the pipeline follows the logarithmic model law and can be described by the logarithmic distribution equation. Therefore, different calculation methods are used for calculation. Furthermore, since the main pipeline mainly plays the role of transporting water and fertilizer, there may be more bends during the transportation process, and the branch pipeline mainly plays the role of dispersing the internal water and fertilizer to different irrigation areas in the farmland, and its bends are less or even non-existent. Therefore, in order to simplify the calculation amount, the influence of the bends in the branch pipeline on the flow velocity can be ignored, and it can be corrected by adjusting the fluctuation coefficient, while the influence of the bends in the main pipeline on the flow velocity needs to be considered. In other words, after ignoring the bends of the branch pipe, the branch pipe can be analyzed and considered as a straight pipe, and the center of the pipe can be determined according to the straight pipe. For example, a branch pipe has a total length of 100 meters and has a bend. The lengths before and after the bend are 20 meters near the entrance and 80 meters near the entrance and exit respectively. Then, after the center of the pipe is determined as a straight pipe, it is 30 meters near the bend and 50 meters near the exit. Specifically, the Poiseuille equation is used for calculation at the first bend of the main pipe, and a variant of the Bernoulli equation is used for calculation at subsequent bends. This method can take into account the impact of the multi-bend characteristics of the main pipe on the flow, and improves the reliability of complex pipe network modeling by accurately calculating the changes in flow velocity and pressure at the bends.

[0030] In this step, the impact of the multi-bend characteristics of the main pipeline on the flow is comprehensively considered, and the differences in the characteristics of laminar flow and turbulent flow are also taken into account. At the same time, error correction and pump pressure regulation are combined to ensure high accuracy of pressure and flow rate calculations, improve the reliability of complex pipeline network modeling, ensure high accuracy of pressure and flow rate calculations, and the dynamic mechanism of error correction and key point pressure adjustment can also adapt to pressure changes under various operating conditions, providing guarantee for system stability.

[0031] S3: Collect the soil temperature and humidity of the irrigation area corresponding to each sprinkler, generate a relationship model between the soil temperature and humidity, the actual pressure and the nozzle valve opening and closing degree, and adjust the nozzle valve opening and closing degree based on the ideal soil temperature and humidity.

[0032] The logic for generating the relationship model between the soil temperature and humidity, actual pressure, and the valve opening degree of the sprinkler in the irrigation area corresponding to the sprinkler is: First, the ideal pressure at the nozzle is corrected based on the error coefficient. The calculation method is: ; Then, the corrected ideal pressure at the sprinkler head, the nozzle valve opening and closing degree, and soil temperature are taken as independent variables, and soil moisture is taken as the dependent variable. A multivariate regression model is constructed as the relationship model between soil temperature and humidity, actual pressure, and nozzle valve opening and closing degree. The model is expressed as follows: ; In the formula are model parameters, , Respectively represent The soil moisture and soil temperature of the irrigation area corresponding to each sprinkler head, Indicates The opening and closing degree of the valve of each nozzle.

[0033] The logic for adjusting the opening and closing degree of the sprinkler valve is: Calculate the flow rate at each nozzle in the branch pipe, and then calculate the actual pressure at each nozzle; Substitute ideal soil moisture, soil temperature, and actual pressure into the multiple regression model; The multivariate regression model is solved to obtain the optimal valve opening and closing degree of each nozzle and make adjustments.

[0034] In most traditional methods, sprinkler flow control is performed only based on pressure or soil moisture, and the correlation between soil temperature and humidity, pressure and valve opening and closing degree is not comprehensively considered, resulting in insufficient irrigation accuracy. When controlling the valve opening and closing degree, only static control methods are used, lacking dynamic adjustment capabilities based on real-time data, and it is difficult to cope with spatial differences in soil moisture or the dynamic needs of crop growth. Moreover, when considering the irrigation effect, only soil moisture is focused on, while the impact of soil temperature on crop growth and evaporation rate is ignored, resulting in limited irrigation effect.

[0035] In this step, by constructing a multivariate regression model between soil temperature and humidity, pressure and valve opening and closing degree, we can comprehensively evaluate the impact of various factors on irrigation effects and improve the prediction accuracy of soil moisture status. At the same time, through real-time data collection and error correction, the nozzle valve opening and closing degree is optimized based on the ideal soil temperature and humidity to ensure that the soil moisture in the irrigation area is always within the range suitable for crop growth. Customized water and fertilizer supply is provided to each irrigation area to avoid drought or excessive irrigation, maximize the suitability of the crop growth environment, and flexibly adjust the model parameters to meet the needs of different crops and soils, laying the foundation for large-scale promotion.

[0036] In summary, the present invention solves the problems of inaccurate pressure calculation, uneven velocity distribution and imprecise irrigation control in the existing irrigation system through differentiated modeling and dynamic adjustment strategies, which improves the accuracy of the irrigation system and the efficiency of resource utilization. By adopting laminar and turbulent models for the main pipeline and branch pipeline respectively, combined with the error correction mechanism, the high accuracy of the pressure and velocity calculation in the pipeline is ensured; with the help of a multivariate regression model, the soil temperature and humidity, nozzle pressure and valve opening are dynamically associated to achieve uniformity and intelligent control of global irrigation; finally, by real-time collection of soil parameters and optimization of nozzle flow distribution, water and fertilizer waste is greatly reduced, ensuring that the soil environment is maintained in an ideal state. Compared with traditional technologies, this solution not only improves irrigation efficiency, but is also suitable for different soil and crop environments, providing an intelligent, efficient and water-saving solution for large-scale agricultural irrigation systems.

[0037] The present invention also provides a one-to-two water-fertilizer irrigation pressure regulating device based on a sensor network, which is used to execute the above-mentioned one-to-two water-fertilizer irrigation pressure regulating method based on a sensor network, specifically comprising: Hydraulic sensing module: The hydraulic sensing module is used to collect the total flow of the irrigation system, the initial pump pressure and initial flow rate at the inlet of the main pipeline, and the measured pressure and flow rate at the connection between the main pipeline and the branch pipeline and at the outlet of the branch pipeline; The temperature and humidity sensing module includes several groups of temperature sensors and humidity sensors, which are arranged at the center of the irrigation area corresponding to the sprinkler head and are used to detect the soil temperature and soil humidity of the irrigation area; A model building module, the model building module is used to build pressure distribution models in the main pipeline and the branch pipeline respectively; A data analysis module is used to generate a relationship model between soil temperature and humidity, actual pressure and the opening and closing degree of the sprinkler valve, and to generate control instructions for the sprinkler valve based on the ideal soil temperature and humidity; The valve control module is used to adjust the opening and closing degree of the valve of the sprinkler according to the control instructions.

[0038] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0039] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0040] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0041] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A one-to-two water and fertilizer irrigation pressure regulation method based on a sensor network, characterized in that: The specific steps include: S1: Collect the hydraulic parameters and pipeline parameters of the main pipeline and branch pipeline in the irrigation system, and build the pressure distribution models in the main pipeline and branch pipeline respectively based on the Bernoulli equation; S2: Generate corresponding pressure distributions based on the pressure distribution models of the main pipeline and the branch pipeline, obtain the actual pressures of the key points in the main pipeline and each nozzle on the branch pipeline, and adjust the hydraulic parameters based on the actual pressures of the key points in the main pipeline; S3: Collect the soil temperature and humidity of the irrigation area corresponding to each sprinkler, generate a relationship model between the soil temperature and humidity, the actual pressure and the nozzle valve opening and closing degree, and adjust the nozzle valve opening and closing degree based on the ideal soil temperature and humidity.

2. The one-to-two water-fertilizer irrigation pressure regulation method based on a sensor network according to claim 1 is characterized in that: The hydraulic parameters include the total flow of the irrigation system, the initial pump pressure and initial flow rate at the inlet of the main pipeline, and the measured pressure and measured flow rate at the connection between the main pipeline and the branch pipeline and at the outlet of the branch pipeline; The pipeline parameters include the pipeline length, pipeline diameter, pipeline thickness, friction coefficient, and bending coefficient of the main pipeline and the branch pipeline.

3. The one-to-two water-fertilizer irrigation pressure regulation method based on a sensor network according to claim 2 is characterized in that: The logic for constructing the pressure distribution model in the main pipeline and branch pipeline is: Taking the height of the main pipeline inlet as the reference height, the relationship model between the ideal pressure, flow velocity and height difference in the main pipeline and branch pipeline is constructed based on the Bernoulli equation, which is expressed as: ； ； in represents the ideal pressure at the 𝑖th critical point in the main pipeline, Indicates the branch pipe The ideal pressure at each nozzle, subscript represents the index of the key point, , is the number of key points, Indicates the index of the sprinkler head. , is the number of nozzles, represents the density of the fluid in the irrigation system, represents the flow velocity at the 𝑖th key point in the main pipe, Indicates the branch pipe The flow rate at each nozzle, represents the acceleration due to gravity, represents the height difference between the 𝑖th key point in the main pipeline and the reference height, Indicates the branch pipe The height difference between the nozzle and the reference height, represents the equation constant, where the equation constant is calculated as: ； in , represent the initial pump pressure and initial flow rate at the main pipeline inlet respectively; Then calculate the pressure loss in the main pipeline and branch pipeline, the calculation method is: ； ； In the formula , Respectively represent the pressure loss in the main pipeline and branch pipeline, , Represent the friction coefficients of the main pipeline and branch pipeline respectively, , Respectively represent the pipeline lengths of the main pipeline and branch pipeline, , Respectively represent the pipe diameters of the main pipe and branch pipe; The actual pressure in the main pipeline and branch pipeline is expressed as: ； ； In the formula represents the actual pressure at the 𝑖th key point in the main pipeline, Indicates the branch pipe The actual pressure at each nozzle.

4. The one-to-two water-fertilizer irrigation pressure regulation method based on a sensor network according to claim 3 is characterized in that: The key points in the main pipeline include the bending points of the main pipeline and the connection points between the main pipeline and the branch pipeline. The logic for adjusting the hydraulic parameters based on the actual pressure of the key points in the main pipeline is: Calculate the actual pressure of each key point in the main pipeline respectively, compare the actual pressure at the connection between the main pipeline and the branch pipeline with the measured pressure at the inlet of the branch pipeline in the hydraulic parameters, and generate the corresponding error coefficient. The calculation method is: ； In the formula , Respectively represent the actual pressure at the connection between the main pipeline and the two branch pipelines, , Respectively represent the measured pressure at the connection between the main pipeline and the two branch pipelines; Then the actual pressure of the key point is corrected using the error coefficient. The corrected actual pressure is expressed as: ； By adjusting the initial pump pressure at the main pipeline inlet, the actual pressure at each key point after correction meets , the adjustment is considered complete, where Indicates the preset minimum pressure. Indicates the pressure threshold of the main pipeline and branch pipeline, represents the coefficient of volatility, and .

5. The one-to-two water-fertilizer irrigation pressure regulation method based on a sensor network according to claim 4 is characterized in that: The flow velocity calculation methods at different locations in the main pipeline and branch pipeline are: ； ； In the formula represents the total flow of the irrigation system, , denote the 𝑖th key point and the The distance between each nozzle and the center of the pipe, Indicates the bending coefficient of the pipe. Indicates the pipe thickness of the branch pipe.

6. The one-to-two water-fertilizer irrigation pressure regulation method based on a sensor network according to claim 4 is characterized in that: The logic for generating the relationship model between the soil temperature and humidity, actual pressure, and the valve opening degree of the sprinkler in the irrigation area corresponding to the sprinkler is: First, the ideal pressure at the nozzle is corrected based on the error coefficient. The calculation method is: ； Then, the corrected ideal pressure at the sprinkler head, the nozzle valve opening and closing degree, and soil temperature are taken as independent variables, and soil moisture is taken as the dependent variable. A multivariate regression model is constructed as the relationship model between soil temperature and humidity, actual pressure, and nozzle valve opening and closing degree. The model is expressed as follows: ； In the formula are model parameters, , Respectively represent The soil moisture and soil temperature of the irrigation area corresponding to each sprinkler head, Indicates The opening and closing degree of the valve of each nozzle.

7. The one-to-two water-fertilizer irrigation pressure regulation method based on a sensor network according to claim 6 is characterized in that: The logic for adjusting the opening and closing degree of the sprinkler valve is: Calculate the flow rate at each nozzle in the branch pipe, and then calculate the actual pressure at each nozzle; Substitute ideal soil moisture, soil temperature, and actual pressure into the multiple regression model; The multivariate regression model is solved to obtain the optimal valve opening and closing degree of each nozzle and make adjustments.

8. A one-to-two water and fertilizer irrigation pressure regulating device based on a sensor network, characterized in that: The one-to-two water-fertilizer irrigation pressure regulating device based on a sensor network is used to execute the one-to-two water-fertilizer irrigation pressure regulating method based on a sensor network as claimed in any one of claims 1 to 7, specifically comprising: A hydraulic sensing module, which is used to collect the total flow of the irrigation system, the initial pump pressure and initial flow rate at the inlet of the main pipeline, and the measured pressure and flow rate at the connection between the main pipeline and the branch pipeline and at the outlet of the branch pipeline; A temperature and humidity sensing module, wherein the temperature and humidity sensing module includes a plurality of groups of temperature sensors and humidity sensors, which are arranged at the center of the irrigation area corresponding to the sprinkler head and are used to detect the soil temperature and soil humidity of the irrigation area; A model building module, wherein the model building module is used to respectively build pressure distribution models in the main pipeline and the branch pipeline; A data analysis module, the data analysis module is used to generate a relationship model between soil temperature and humidity, actual pressure and the opening and closing degree of the sprinkler valve, and generate a control instruction for the sprinkler valve based on the ideal soil temperature and humidity; A valve control module, wherein the valve control module is used to adjust the opening and closing degree of the valve of the nozzle according to the control instruction.

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