Water and fertilizer integrated control method and device for central pivot type sprinkling machine

Abstract

The invention discloses a water and fertilizer integrated control method and device for a central pivot type sprinkler, and the method comprises the steps: giving a certain irrigation quota, the fertilizer application amount per mu and the fertilizer type according to the related parameters of the central pivot type sprinkler and a fertilizer injection pump; the operation duration and the working frequency of the fertilizer injection pump of the sprinkling machine in the fertilizer solution sprinkling process, the operation duration and the working frequency of the fertilizer injection pump in the backwashing process and the operation duration of the sprinkling machine in the clear water sprinkling process can be calculated, and a strategy of firstly sprinkling the fertilizer solution and then synchronously carrying out the backwashing process and the clear water sprinkling process is formed; and the walking speed of the sprinkling machine and the frequency of the fertilizer injection pump are accurately regulated and controlled through the control system, so that full-automatic precision operation of water and fertilizer integration is realized. According to the invention, based on EC or pH feedback regulation, accurate regulation and control of the fertilizer injection amount can be realized without adopting metering equipment such as a flowmeter, the problem that the fertilization concentration change is relatively large due to large water pressure fluctuation of a large sprinkling irrigation machine is avoided, and the cost is reduced while water and fertilizer collaborative accurate application is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of water-fertilizer integration, and in particular relates to a water-fertilizer integration control method and device for a center-supported sprinkler irrigation machine. Background Art

[0002] The integrated water and fertilizer technology has significant effects of saving water, reducing weight, and increasing production. It has become a key measure for my country to increase grain production capacity, improve water and fertilizer utilization efficiency, and alleviate water shortage. The center pivot sprinkler has the characteristics of high degree of automation, large single-machine control area, strong adaptability, and can significantly reduce water consumption and labor costs. Relevant research shows that the use of large sprinklers for integrated water and fertilizer spraying can reduce labor input, avoid damage to crops during the operation of conventional agricultural machinery, and improve the yield and quality of crops while improving the utilization rate of water and fertilizer.

[0003] However, the water-fertilizer integration of large sprinklers in my country is still in its early stages, and there is a big gap compared with developed countries such as the United States. A small number of users who use large sprinklers for irrigation and fertilization mostly use products from other fields as fertilizer injection equipment. The matching and performance of the equipment cannot meet the requirements, and there is a lack of appropriate irrigation and fertilization strategies, which leads to problems such as poor accuracy of the system's water-fertilizer ratio and extensive water-fertilizer mixing control.

[0004] Therefore, conducting relevant research on the special water-fertilizer integrated device of the center-pivot sprinkler suitable for intensive agricultural production and the corresponding irrigation and fertilization strategy is in line with national policies and the actual requirements of domestic applications, and is of great significance to improving the utilization rate of water resources and fertilizers in my country, increasing crop yields, and protecting soil and groundwater. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a water-fertilizer integrated device with stable fertilizer injection flow suitable for center pivot sprinkler irrigation, which can accurately control the fertilizer concentration and fertilizer amount through irrigation and fertilization strategy, and based on E C Or pH control to achieve fully automatic precision operation of water and fertilizer integration.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A first aspect of the present invention provides a center pivot sprinkler irrigation machine water and fertilizer integration control method, which is used to control a center pivot sprinkler irrigation machine water and fertilizer integration device, wherein the center pivot sprinkler irrigation machine water and fertilizer integration device comprises a center pivot sprinkler irrigation machine, a fertilizer injection pump and a fertilizer storage unit connected to each other, and the control method comprises:

[0008] Obtain the inherent parameters of the sprinkler, and set the fertilizer application amount per mu, irrigation quota and fertilizer type for this irrigation and fertilization;

[0009] Collect the inflow flow of the sprinkler and the E of the clean water in the sprinkler main line before the start of this fertilizer injection irrigation. c value or pH value;

[0010] According to the inherent parameters of the sprinkler, the fertilizer application amount per mu, the irrigation quota and the fertilizer type of the current irrigation and fertilization, and the inflow flow rate, the working parameters of the sprinkler and the fertilizer injection pump are calculated to form the current irrigation and fertilization strategy, specifically, the strategy of first spraying fertilizer solution, then synchronously performing the backwashing process and spraying clean water;

[0011] Control the central pivot sprinkler irrigation machine water-fertilizer integrated equipment to execute the current irrigation and fertilization strategy;

[0012] In the process of controlling the central pivot sprinkler irrigation machine water-fertilizer integrated equipment to execute the current irrigation and fertilization strategy, the concentration of the sprinkler fertilizer solution is monitored and feedback-adjusted: the corresponding fertilizer solution concentration inversion prediction model is selected according to the fertilizer type, and the E of the fertilizer solution sprayed for this irrigation and fertilization is obtained according to the spraying fertilizer solution concentration and the selected fertilizer solution concentration inversion prediction model. c The predicted value or pH predicted value is compared with the E of the sprayed fertilizer solution collected after the start of fertilization. c The water or pH value is compared, and the control instructions of the central pivot sprinkler water and fertilizer integration equipment are formed based on the comparison results.

[0013] In some embodiments, the inherent parameters of the sprinkler include the overall length of the sprinkler, the range of the nozzle installed at the end of the sprinkler, the field spraying water utilization coefficient, the field surface slip coefficient, the rated speed of the drive motor, the effective radius of the matching tire, the drive motor reducer transmission ratio, the wheel reducer transmission ratio, the distance between the center point of the center support of the sprinkler and the end tower vehicle, the rated frequency of the fertilizer injection pump and the actual flow of the fertilizer injection pump after calibration.

[0014] In some embodiments, the E c The pH value and the pH value are measured by an E installed downstream of the junction of the fertilizer injection pipeline and the sprinkler main pipeline. c The flow rate is collected by the sensor and the pH sensor, and the inflow flow is collected by the flow meter installed at the water inlet of the main pipeline of the sprinkler irrigation machine.

[0015] In some embodiments, the fertigation strategy includes:

[0016] Preset program: Determine the coverage area A0 of the sprinkler and the shortest operation time t of the sprinkler in one week according to the inherent parameters of the sprinkler min ;

[0017] Sprinkler irrigation fertilizer solution: Determine the total fertilizer injection volume V of this sprinkler irrigation fertilizer solution based on the maximum solubility S of the given fertilizer at room temperature, the set fertilizer application rate M per mu, and the coverage area A0 of the sprinkler irrigation machine.f , and according to the total amount of fertilizer injected V f and the volume V of the fertilizer storage container in the fertilizer storage unit t Determine the actual amount of fertilizer V injected in this sprinkler irrigation; according to the sprinkler irrigation machine flow Q0, the set fertilizer depth h of the sprinkler irrigation process f , the coverage area A0 of the sprinkler and the shortest operation time t of the sprinkler in one week min , determine the setting value x of the percentage timer of the sprinkler during the fertilizer irrigation process f ; According to the shortest operation time of the sprinkler in a week t min and the setting value x of the percentage timer of the sprinkler during the fertilizer liquid irrigation process f , calculate the operating time t of the sprinkler during the fertilizer irrigation process f According to the actual amount of fertilizer V injected by the current sprinkler irrigation, the rated frequency f of the fertilizer injection pump d , the actual flow rate of the fertilizer injection pump after the verification q d and the operating time t of the sprinkler irrigation process f Determine the operating frequency f of the fertilizer injection pump;

[0018] Backwash process: Set the running time of the fertilizer injection pump during the backwash process t c And the operating frequency f c ;

[0019] Sprinkler irrigation water: according to the current irrigation quota h and the fertilizer liquid depth h during the sprinkler irrigation process f Calculate the irrigation depth h of sprinkler irrigation water w According to the inflow flow Q0 of the sprinkler, the coverage area A0 of the sprinkler, and the shortest operation time t of the sprinkler in one week min and the irrigation depth h of the sprinkler irrigation water w , determine the setting value x of the percentage timer of the sprinkler during the sprinkler irrigation process w ; According to the shortest operation time of the sprinkler in a week t min and the setting value x of the percentage timer of the sprinkler during the sprinkler irrigation process w , calculate the running time t of the sprinkler irrigation process w , and t w >t c ;

[0020] According to the operation time t of the sprinkler irrigation process f and the operating frequency f of the fertilizer injection pump, the operating time t of the fertilizer injection pump during the backwashing process c And the working frequency f of the fertilizer injection pump c The running time of the sprinkler irrigation machine during the sprinkler irrigation water cleaning process is t w, and the total duration of the sprinkler irrigation and fertilization integration operation t=t f +t w The irrigation and fertilization strategy is formed.

[0021] In some embodiments, the sprinkler coverage area A0 is calculated according to the following formula:

[0022]

[0023] Where, L s is the length of the sprinkler; R is the range of the sprinkler installed at the end of the sprinkler;

[0024] The shortest operation time of the sprinkler in a week is t min , calculated according to the following formula:

[0025]

[0026] Where, L f is the distance between the center point of the central support of the sprinkler and the terminal tower vehicle; i1 is the transmission ratio of the drive motor reducer; i2 is the transmission ratio of the wheel reducer; n is the rated speed of the drive motor; r is the effective radius of the matching tire; η is the field surface slip coefficient, which depends on the tire pattern, tire pressure and soil compactness, and is taken as 0.92~0.97;

[0027] The total amount of fertilizer injected by the sprinkler this time is V f , calculated according to the following formula:

[0028]

[0029] In the formula, k is the coefficient set to ensure that the fertilizer is fully dissolved, which is set to 1.3-1.6;

[0030] The actual injection amount V of the fertilizer solution for this sprinkler irrigation is calculated according to the following formula:

[0031] V=NV t

[0032]

[0033] In the formula, N is the number of times the fertilizer solution is dispensed for this irrigation. The N value obtained by the above formula is rounded up as the number of times the fertilizer solution is dispensed for this irrigation.

[0034] The setting value x of the percentage timer of the sprinkler during the fertilizer liquid irrigation process f , calculated according to the following formula and rounded down to get:

[0035]

[0036] Where η pis the field spraying water utilization coefficient, which is related to the wind speed. When the wind speed is lower than 3.4 m / s, η p Take 0.8~0.9, when the wind speed is 3.4~5.4m / s, η p Take 0.7~0.8; the fertilizer liquid depth h in the process of sprinkler irrigation f The value shall not be less than 5mm;

[0037] The operating time of the sprinkler during the fertilizer liquid irrigation process is t f , calculated according to the following formula:

[0038]

[0039] The operating frequency f of the fertilizer injection pump is calculated according to the following formula:

[0040]

[0041] The irrigation depth of the sprinkler irrigation water is h w , calculated according to the following formula:

[0042] h w =hh f

[0043] The setting value x of the percentage timer of the sprinkler during the sprinkler irrigation process w , calculated according to the following formula and rounded down to get:

[0044]

[0045] The running time of the sprinkler irrigation machine during the sprinkler irrigation water cleaning process is t w , calculated according to the following formula:

[0046]

[0047] In the formula, t min The minimum time the pivot machine runs in a week.

[0048] In some embodiments, in the process of controlling the central pivot sprinkler irrigation machine water-fertilizer integrated device to execute the current irrigation and fertilization strategy, the fertilizer solution concentration is monitored and feedback-adjusted, specifically including:

[0049] The concentration of the fertilizer stock solution configured in the fertilizer liquid container of the fertilizer storage unit during the process of the central pivot sprinkler irrigation is calculated according to the following formula:

[0050]

[0051] In the formula, C is the concentration of the original fertilizer solution; M is the amount of fertilizer applied per mu; A0 is the coverage area of ​​the sprinkler; V is the actual amount of fertilizer injected in this sprinkler irrigation;

[0052] According to the sprinkler machine inlet flow Q0, the actual flow of the fertilizer pump after verification q d The concentration of the sprinkler fertilizer solution is calculated based on the concentration of the configured fertilizer stock solution, and the calculation formula is as follows:

[0053]

[0054] In the formula, C s is the concentration of fertilizer solution for sprinkler irrigation;

[0055] According to the fertilizer type, the corresponding fertilizer solution concentration inversion prediction model is selected. The fertilizer solution concentration inversion prediction model is used to reflect the sprinkler irrigation fertilizer solution concentration and the E c The functional relationship between the value or pH value;

[0056] The concentration of the sprayed fertilizer solution C s The fertilizer concentration inversion prediction model is introduced to obtain the E of the fertilizer solution for this irrigation and fertilization sprinkler irrigation. c The predicted value and pH value are compared with the E of the fertilizer solution sprayed after the fertilization begins. c The value or pH value is compared. If the comparison result exceeds the set threshold, a shutdown signal is issued and a shutdown report is generated. If the comparison result does not exceed the set threshold, the current fertigation strategy will continue to be executed until the operating time of the sprinkler reaches the total time of the sprinkler water-fertilizer integration operation, and this fertigation ends.

[0057] In some embodiments, when a strong electrolyte is used as the fertilizer, the fertilizer solution concentration inversion prediction model is:

[0058] E c =aC s +b

[0059] In the formula, E c is the conductivity; a is the first coefficient, which needs to be calibrated through experiments; b is the E of the irrigation water before the start of fertilizer injection c value;

[0060] When acidic or alkaline fertilizer is used as fertilizer, the inversion prediction model of fertilizer solution concentration is:

[0061] pH=yC s +z

[0062] In the formula, pH is acidity and alkalinity; y is the second coefficient, which needs to be calibrated through experiments; z is the pH value of irrigation water before fertilization begins.

[0063] A second aspect of the present invention provides a center support type sprinkler irrigation water and fertilizer integrated device, comprising a fertilization device, a center support, a control system and a plurality of pipelines, wherein the fertilization device comprises a fertilizer injection pump and a fertilizer storage unit, and the center support comprises a center support bracket and a sprinkler irrigation main pipeline located in the middle thereof;

[0064] The fertilizer injection pump is connected between the sprinkler main line and the fertilizer storage unit through a pipeline, and injects the fertilizer liquid in the fertilizer storage unit into the sprinkler main line according to the control instruction of the control system; wherein the inlet of the fertilizer injection pump is connected to the fertilizer outlet at the bottom of the fertilizer storage container in the fertilizer storage unit through a fertilizer suction pipeline; the outlet of the fertilizer injection pump is connected to the sprinkler main line through the fertilizer injection pipeline; the sprinkler main line is connected to the inlet of the fertilizer storage container through a water supply pipeline, and a backwash pipeline is connected between the water supply pipeline and the fertilizer suction pipeline, and the fertilizer injection pump is flushed through the backwash pipeline after each spraying of fertilizer liquid.

[0065] The fertilizer storage unit is used to prepare fertilizer solution of corresponding concentration according to the control instruction of the control system, and the fertilizer storage unit includes the connected fertilizer storage container and the agitator;

[0066] The control system includes a sensor unit, a valve group, and a first control cabinet and a second control cabinet which are arranged on one side of the core support bracket and communicate with each other; wherein,

[0067] The sensing unit includes a liquid level sensor installed on the top of the fertilizer storage container, a pressure switch installed on the fertilizer injection pipeline, and a flow meter, an E c Sensors and pH sensors;

[0068] The valve group includes a water replenishment electric valve, a fertilizer suction electric valve, a fertilizer injection electric valve, and a backwashing electric valve, which are respectively installed on corresponding pipelines;

[0069] The second control cabinet is used to calculate the working parameters of the sprinkler and the fertilizer injection pump according to the parameters set by the user and the inflow flow of the sprinkler collected by the flow meter before the start of fertilizer injection, form the current irrigation and fertilization strategy and display it to the user; control the operation of the fertilization equipment, the sensor unit and the valve group according to the current irrigation and fertilization strategy, and monitor and feedback-adjust the concentration of the sprinkler fertilizer solution during the control process;

[0070] The first control cabinet is used to control the start and stop, travel speed and running time of the sprinkler, and the start and stop of the main water supply pump of the sprinkler according to the current irrigation and fertilization strategy.

[0071] In some embodiments, the fertilizer suction pipeline is also installed with a fertilizer suction filter and a fertilizer suction manual valve, the water supply pipeline is also installed with a water supply filter and a water supply manual valve, the fertilizer injection pipeline is also installed with a check valve and a fertilizer injection manual valve, and a manual drain valve is installed at the bottom of the fertilizer storage container.

[0072] In some embodiments, the second control cabinet includes a frequency converter and a second controller disposed inside the second cabinet, and a human-computer interaction unit disposed outside the second cabinet, the second controller integrates an irrigation and fertilization strategy generation module and an irrigation fertilizer concentration control module, the second controller controls the working frequency of the fertilizer injection pump through the frequency converter, and the second controller is connected to the sensor unit, the valve group and the agitator; the first control cabinet includes a percentage timer and a first controller disposed outside and inside the first cabinet respectively, the first controller communicates with the second controller, and the first controller controls the travel speed of the sprinkler through the percentage timer. Features and beneficial effects of the present invention:

[0073] 1) The present invention discloses a method for controlling the integration of water and fertilizer for a center pivot sprinkler. The method can calculate the number of rotations of the sprinkler, the setting value of the percentage counter, the working frequency of the plunger fertilizer pump and other working parameters according to the relevant parameters of the center pivot sprinkler and the fertilizer injection device, given a certain irrigation quota and fertilizer amount, to form an irrigation and fertilization strategy, and accurately control the travel speed of the sprinkler and the frequency of the fertilizer injection pump through the control system to achieve fully automatic precision operation of water and fertilizer integration; in addition, the method adopts an irrigation and fertilization strategy of first spraying fertilizer liquid, then synchronously performing the backwashing process and spraying clean water. Compared with the synchronous application of water and fertilizer, the advantage of this method of first irrigating water and fertilizer and then irrigating with clean water is that after water and fertilizer irrigation, the fertilizer liquid remaining on the leaves is immediately rinsed with irrigation clean water, which improves the fertilizer utilization rate while preventing the fertilizer residue from damaging the crop leaves.

[0074] 2) The present invention discloses a center-pivot sprinkler irrigation machine water-fertilizer integrated device. The device uses a plunger-type fertilizer injection pump as the core fertilization equipment. Compared with other fertilization equipment, the present invention can achieve precise adjustment of the amount of fertilizer injection without the use of flow meters and other metering equipment, avoiding the problem of large changes in fertilizer concentration caused by large water pressure fluctuations in large sprinklers, and realizing the coordinated and precise application of water and fertilizer while reducing costs; the present invention discloses a special center-pivot sprinkler irrigation machine water-fertilizer integrated device with a backwash function. After the irrigation and fertilization process, the fertilization device and the residual fertilizer liquid inside the pipeline can be cleaned through the backwash pipeline to prevent the residual fertilizer liquid from damaging the water-fertilizer integrated system; the present invention discloses A special water-fertilizer integration device for a center-support type sprinkler is equipped with a manual valve. When the system is powered off or the electric valve cannot work normally, the system can be controlled by the manual valve; a special water-fertilizer integration device for a center-support type sprinkler disclosed by the present invention is equipped with a safety protection device. A pressure switch is installed on the fertilizer injection pipeline. When the fertilizer injection pipeline fails or the fertilizer injection device fails, and the pressure in the fertilizer injection pipeline is greater than the working pressure of the fertilizer injection pump, the control system will automatically stop the fertilizer liquid spraying process and feedback to the human-computer interaction unit to prevent excessive pressure from damaging the system, thereby improving the safety of system operation.

[0075] 3) The present invention can monitor the water and fertilizer concentration of the main pipeline of the central pivot sprinkler in real time and perform feedback control during the water and fertilizer integration process; first, before the fertilizer injection process, the flow meter, E c The sensor and pH sensor respectively measure the inflow flow of the main pipeline of the center pivot sprinkler and the E of the irrigation water. c and pH value; then, based on the water-fertilizer integration strategy given by the irrigation and fertigation control system, the above formula is used to calculate the concentration of the fertilizer solution sprayed by the center pivot sprinkler, and the functional relationship between the corresponding spray fertilizer concentration, conductivity and pH value is selected through the preset fertilizer type to calculate the E of the fertilizer solution sprayed by the water-fertilizer integration strategy. c Or pH value; finally, the calculated E c Or pH value and E measured during fertilizer injection c Or pH value, if the difference between the two is greater than the set upper limit of the difference, the system will automatically stop the fertilizer spraying process and feedback to the human-computer interaction unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 An overall flow chart of a method for controlling water and fertilizer integration of a center pivot sprinkler provided by an embodiment of the first aspect of the present invention;

[0077] Figure 2 for Figure 1 The control method shown generates a flow chart of the irrigation and fertilization strategy;

[0078] Figure 3 Based on Figure 1 A flow chart of a method for monitoring and feedback control of fertilizer solution concentration during fertilization by the control method;

[0079] Figure 4 A schematic diagram of the overall structure of a water-fertilizer integrated device for a center-supported sprinkler irrigation machine provided in an embodiment of the second aspect of the present invention;

[0080] Figure 5 for Figure 4 A schematic diagram of the structure of a plunger-type fertilizer injection pump and its pipeline in the device shown;

[0081] Figure 6 for Figure 4 A schematic diagram of the structure of the fertilizer storage unit and its supporting pipelines in the device shown;

[0082] Figure 7 for Figure 4 A schematic diagram of the structure of the central support shaft and the control system in the device shown;

[0083] Figure 8 for Figure 4 The internal structure block diagram of the control system in the device shown. DETAILED DESCRIPTION

[0084] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0085] On the contrary, the present application covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present application as defined by the claims. Further, in order to make the public have a better understanding of the present application, some specific details are described in detail in the detailed description of the present application below. Those skilled in the art can fully understand the present application without the description of these details.

[0086] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the restrictive conditions that can be implemented in this application, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that can be produced by this application and the purposes that can be achieved, should still fall within the scope of the technical content disclosed in this application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of narration, and are not used to limit the scope of the implementation of this application. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of this application without substantial change in the technical content.

[0087] See also Figure 1 The first aspect of the present invention provides a central pivot sprinkler irrigation machine water-fertilizer integration control method, which is used to control the central pivot sprinkler irrigation machine water-fertilizer integration equipment, the central pivot sprinkler irrigation machine water-fertilizer integration equipment includes a central pivot sprinkler irrigation machine (hereinafter referred to as "sprinkler irrigation machine"), a fertilizer injection pump and a fertilizer storage unit connected to each other. The control method of this embodiment includes the following steps:

[0088] Obtain the inherent parameters of the sprinkler, and set the fertilizer application amount per mu, irrigation quota and fertilizer type for this irrigation and fertilization;

[0089] Collect the inflow flow of the sprinkler and the E of the clean water in the sprinkler main line before the start of this fertilizer injection irrigation. c value or pH value;

[0090] According to the inherent parameters of the sprinkler, the fertilizer application amount M per mu, the irrigation quota h and the fertilizer type of this irrigation and fertilization are set, and the working parameters of the sprinkler and the fertilizer injection pump are calculated based on the sprinkler's inflow flow before the start of fertilizer injection, so as to form the irrigation and fertilization strategy for this time, specifically, the strategy of first spraying fertilizer liquid, then synchronously performing the backwashing process and spraying clean water;

[0091] Control the central pivot sprinkler water and fertilizer integrated equipment to implement the irrigation and fertilization strategy;

[0092] In the process of the central pivot sprinkler water-fertilizer integrated equipment executing the irrigation and fertilization strategy, the concentration of the sprinkler fertilizer solution is monitored and feedback adjusted: the corresponding fertilizer solution concentration inversion prediction model is selected according to the fertilizer type, and the E of the fertilizer solution sprayed for this irrigation and fertilization is obtained according to the spraying fertilizer solution concentration and the selected fertilizer solution concentration inversion prediction model. c The predicted value or pH predicted value is compared with the E of the sprayed fertilizer solution collected after the start of fertilization. c The water or pH value is compared, and the control instructions of the central pivot sprinkler water and fertilizer integration equipment are formed based on the comparison results.

[0093] In some embodiments, the inherent parameters of the sprinkler include the overall length L of the sprinkler. s (unit: m), the range R of the sprinkler installed at the end of the sprinkler (unit: m), the field spraying water utilization coefficient η p , field surface slip coefficient η, rated speed of driving motor n (unit: r / min), effective radius of matching tire r (unit: m), transmission ratio i1 of driving motor reducer, transmission ratio i2 of wheel reducer, distance L between the center point of the center support of the sprinkler and the end tower vehicle f (Unit: m), rated frequency f of fertilizer injection pump d (Unit: Hz) and the actual flow rate q of the fertilizer injection pump after calibrationd (Unit: L / h), q d It can be obtained through the drop value of the liquid level sensor in the fertilizer storage unit within a certain period of time.

[0094] In some embodiments, a flow meter, an E c Sensor and pH sensor; Among them, the flow meter is located at the water inlet of the sprinkler main line, which is used to collect the clean water flow injected into the sprinkler main line before the start of fertilizer injection, that is, the inflow flow Q0 (unit: m 3 / h); E c The sensor and pH sensor are installed downstream of the junction of the fertilizer injection pipeline and the sprinkler main pipeline to collect the pH of the irrigation water before the start of fertilizer injection. c value and pH value, as well as the E of the fertilizer solution sprayed during fertilization c value and pH value.

[0095] In some embodiments, see Figure 2 , which is a specific flow chart for generating this irrigation and fertilization strategy. In the embodiment of the present invention, a strategy of first spraying fertilizer liquid, then synchronously performing the backwashing process and spraying clean water is adopted, and there is no time interval between water-fertilizer irrigation and clean water irrigation. Considering that fertilization and irrigation should be considered in coordination in the water-fertilizer integration operation of the sprinkler, each time fertilization is completed, it is necessary to spray clean water to a certain depth to meet the irrigation quota required by the crop and clean the leaf surface. Compared with the synchronous application of water and fertilizer, the advantage of this embodiment of first spraying fertilizer liquid, then synchronously performing the backwashing process and spraying clean water is that: after the spraying of fertilizer liquid is completed, the residual fertilizer liquid inside the fertilizer injection pump and its connecting pipeline is immediately cleaned to prevent the residual fertilizer liquid from damaging the water-fertilizer integration equipment of the center pivot sprinkler. At the same time, the residual fertilizer liquid on the leaves is eluted by irrigation clean water, which improves the fertilizer utilization rate while preventing the residual fertilizer from damaging the crop leaves. The specific steps for generating this irrigation and fertilization strategy in this embodiment include:

[0096] Preset program: Determine the coverage area A0 (unit: mu) of the sprinkler and the shortest operation time t of the sprinkler in one week according to the inherent parameters of the sprinkler min (Unit: h);

[0097] Sprinkler irrigation fertilizer solution: Determine the total fertilizer injection volume V of this sprinkler irrigation fertilizer solution based on the maximum solubility S (unit: kg / L) of the given fertilizer at room temperature, the set fertilizer application rate M (unit: kg) per mu, and the coverage area A0 of the sprinkler irrigation machine. f (Unit: L), and according to the total amount of fertilizer injected this time, V f and the volume V of the fertilizer storage container in the fertilizer storage unit t (Unit: L) to determine the actual amount of fertilizer V (unit: L) injected into the sprinkler irrigation machine; according to the sprinkler irrigation machine flow rate Q0 (unit: m3 / h), fertilizer liquid depth h during sprinkler irrigation f (Unit: mm), the coverage area A0 of the sprinkler and the shortest operation time t of the sprinkler in a week min , determine the setting value x of the percentage timer of the sprinkler during the fertilizer irrigation process f (Unit: %); Based on the shortest operation time of the sprinkler in a week t min The setting value x of the percentage timer of the sprinkler during the fertilizer irrigation process f , calculate the operating time t of the sprinkler during the fertilizer irrigation process f (Unit: h); based on the actual amount of fertilizer injected V during this irrigation, and the rated frequency f of the fertilizer injection pump d , the actual flow rate of the fertilizer injection pump after verification q d And the operation time of the sprinkler during the fertilizer spraying process f Determine the operating frequency f of the fertilizer injection pump (unit: Hz);

[0098] Backwash process: Set the running time of the fertilizer injection pump during the backwash process t c (unit: m in) and operating frequency f c (Unit: Hz); Among them, the running time of the fertilizer injection pump during the backwash process is t c Set it as a fixed time, usually 10 minutes; the working frequency of the fertilizer injection pump during the backwash process is f c Take the rated frequency f of the fertilizer injection pump as d ;

[0099] Sprinkler irrigation water: based on the current irrigation quota h (unit: mm) and the fertilizer liquid depth h during the sprinkler irrigation process f Calculate the irrigation depth h of sprinkler irrigation water w (Unit: mm); Based on the inflow flow Q0 of the sprinkler, the coverage area A0 of the sprinkler, and the shortest operation time t of the sprinkler in a week min and the irrigation depth of sprinkler water h w , determine the setting value x of the percentage timer of the sprinkler during the sprinkler irrigation process w (Unit: %); Based on the shortest operation time of the sprinkler in a week t min The setting value x of the percentage timer of the sprinkler during the sprinkler irrigation and water cleaning process w , calculate the running time t of the sprinkler irrigation process w (Unit: h), t w >t c ;

[0100] Finally, according to the above calculation, the operating time t of the sprinkler irrigation process is f And the operating frequency f of the fertilizer injection pump, the running time t of the fertilizer injection pump during the backwash process cAnd the working frequency f of the fertilizer injection pump c , the running time of the sprinkler during the sprinkler irrigation water cleaning process t w , and the total duration of the sprinkler irrigation and fertilization integration operation t=t f +t w (Unit: h) forms the irrigation and fertilization strategy. It should be noted that due to the operation time t of the sprinkler irrigation water cleaning process w Generally much longer than the running time of the fertilizer injection pump during the backwash process t c , and the sprinkler irrigation water cleaning process is carried out simultaneously during the backwashing process. Therefore, when calculating the total duration t of the sprinkler irrigation machine's water and fertilizer integration operation, the operating duration t of the fertilizer injection pump during the flushing process is not taken into account c , and the operating time of the sprinkler machine only by the sprinkler fertilizer liquid process t f The running time of sprinkler machine during sprinkler irrigation and water cleaning process w The sum is determined.

[0101] Furthermore, the sprinkler coverage area A0 is the total irrigation area controlled by one rotation around the central support axis, which is also the fertilization area. The calculation formula is as follows:

[0102]

[0103] The shortest operation time of the sprinkler in a week min Depends on the maximum travel speed v of the terminal tower vehicle e (Unit: m / min) and the distance L between the center point of the central support of the sprinkler and the end tower vehicle f , the calculation formula is as follows:

[0104]

[0105] Where η is the field surface slip coefficient, which depends on the tire pattern, tire pressure, soil compactness, etc., and is generally taken as 0.92 to 0.97;

[0106] The total amount of fertilizer injected by the sprinkler this time V f It can be expressed as:

[0107]

[0108] In the formula, S is the maximum solubility of the fertilizer at room temperature (generally 20°C), kg / L; k is the coefficient, which is 1.3 to 1.6 to ensure that the fertilizer is fully dissolved;

[0109] The actual injection amount V of the fertilizer solution for this sprinkler irrigation can be expressed as:

[0110] V=NV t

[0111]

[0112] Where N is the number of fertilizer applications for this irrigation (unit: times), which depends on the volume V of the fertilizer storage container in the fertilizer storage unit. t , since the number of fertilizer distribution is an integer, for the sake of conservatism, the N value is rounded up as the number of fertilizer distribution for this sprinkler irrigation;

[0113] The setting value x of the percentage timer of the sprinkler during the fertilizer irrigation process f Determines the travel speed of the sprinkler during the fertilizer spraying process, x f It can be expressed as:

[0114]

[0115] In the formula, since the percentage setting value of the sprinkler is usually an integer, the x obtained for the sake of conservatism is f The value is rounded down as the setting value of the percentage timer of the sprinkler during the fertilizer liquid sprinkler irrigation process; η p is the field spraying water utilization coefficient, which is related to the wind speed. When the wind speed is lower than 3.4 m / s, η p Take 0.8~0.9, when the wind speed is 3.4~5.4m / s, η p Take 0.7~0.8; According to relevant research, a single irrigation depth of less than 5mm is considered invalid. To prevent excessive volatilization of fertilizer after application, 10mm irrigation volume can be set as the fertilizer liquid depth of the sprinkler irrigation process, that is, h f =10mm;

[0116] Sprinkler irrigation process: Sprinkler machine operation time t f It can be expressed as:

[0117]

[0118] The operating frequency f of the fertilizer injection pump can be calculated by the following formula:

[0119]

[0120] In the formula, take the rated frequency f of the fertilizer injection pump d =50Hz;

[0121] Irrigation depth of sprinkler water h w It can be expressed as:

[0122] h w =hh f

[0123] Where, h is the irrigation quota of the sprinkler irrigation machine's water-fertilizer integrated operation, mm;

[0124] The setting value x of the percentage timer of the sprinkler during the sprinkler irrigation processw Determines the travel speed of the sprinkler during the watering process, x w It can be expressed as:

[0125]

[0126] In the formula, the obtained x w The value is rounded down as the setting value of the percentage timer of the sprinkler during the sprinkler irrigation water cleaning process;

[0127] Sprinkler irrigation water cleaning process sprinkler machine running time t w It can be expressed as:

[0128]

[0129] In some embodiments, see Figure 1 The specific steps for the control center pivot sprinkler water and fertilizer integrated equipment to implement this irrigation and fertilization strategy are as follows:

[0130] First, according to the current irrigation and fertilization strategy, add an appropriate amount of fertilizer to the fertilizer storage container of the fertilizer storage unit, and inject clean water at the same time. When the set water level is reached, fully stir the water-fertilizer mixture in the fertilizer storage container of the fertilizer storage unit; after the fertilizer liquid is fully dissolved, the control system accurately regulates the sprinkler and the fertilizer injection pump based on the current irrigation and fertilization strategy, and the sprinkler starts to spray the fertilizer liquid; after the fertilizer liquid in the fertilizer storage unit is injected, determine whether the fertilization process is over according to the current irrigation and fertilization strategy. If it is not over, repeat the above-mentioned fertilizer injection process. If it is over, start the backwash process to clean the residual fertilizer liquid in the fertilizer injection pump and the fertilization pipeline; at the same time, control the sprinkler based on the current irrigation and fertilization strategy, and the sprinkler continues to move and spray clean water. After the current irrigation quota is met, the irrigation and fertilization process ends. In addition, by collecting the sprinkler inflow flow, E c The corresponding fertilizer solution concentration inversion prediction model is selected based on the preset fertilizer solution type, and the water and fertilizer application information during the irrigation and fertigation process is inverted in real time, that is, the E of the fertilizer solution sprayed during this irrigation and fertigation is obtained. c Predicted value or pH predicted value, provide feedback to the fertigation process.

[0131] In some embodiments, see Figure 3 In the process of the central pivot sprinkler water-fertilizer integrated equipment executing the irrigation and fertilization strategy, the specific steps of monitoring and feedback adjustment of fertilizer solution concentration include:

[0132] The concentration of the fertilizer stock solution in the fertilizer storage container during the above-mentioned center pivot sprinkler irrigation process can be calculated by the following formula:

[0133]

[0134] Where, C is the concentration of the original fertilizer solution, kg / L; M is the amount of fertilizer applied per mu, kg; A0 is the coverage area of ​​the sprinkler, mu; V is the actual amount of fertilizer injected in this sprinkler irrigation, L;

[0135] According to the sprinkler machine inlet flow Q0, the actual flow of the fertilizer pump after verification q d The concentration of the sprinkler fertilizer solution is calculated based on the concentration of the configured fertilizer solution stock solution. The calculation formula is as follows:

[0136]

[0137] In the formula, C s The concentration of the sprayed fertilizer solution, kg / L, refers to the concentration of the fertilizer solution sprayed by the sprinkler nozzle, that is, the concentration of the fertilizer solution in the sprinkler main line;

[0138] According to the fertilizer type, the corresponding fertilizer solution concentration inversion prediction model is selected. The fertilizer solution concentration inversion prediction model is used to reflect the sprinkler irrigation fertilizer solution concentration and the E c The functional relationship between the value or pH value, where

[0139] For strong electrolytes such as potassium chloride, diammonium phosphate, potassium nitrate, and potassium sulfate, their solutions have strong conductivity, and there is the following functional relationship between the concentration of the sprayed fertilizer solution and the conductivity:

[0140] E c =aC s +b

[0141] In the formula, E c is the conductivity, μS / cm; a is the first coefficient, which is calibrated through experiments (taking potassium chloride as an example, a conductivity tester is used to measure the conductivity values ​​of potassium chloride solutions with concentrations of 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55% and 0.6% respectively. The above formula is obtained by fitting the test results to calibrate the coefficient a); b is the measured conductivity of clean water, that is, E c The sensor collects the E of the irrigation water before the start of fertilizer injection c Value, μS / cm;

[0142] For acidic or alkaline solutions such as urea and compound fertilizer solutions, there is a functional relationship between the concentration of the sprayed fertilizer solution and the pH:

[0143] pH=yC s +z

[0144] Wherein: pH is acidity and alkalinity; y is a coefficient, which is calibrated through experiments (the calibration process can refer to the calibration process of coefficient a above); z is the measured pH of clean water, that is, the pH value of irrigation clean water collected by the pH sensor before fertilization begins.

[0145] Based on the above functional relationship, the relationship between the concentration of the sprayed fertilizer solution of different types of fertilizers in the sprinkler main line and the conductivity or pH can be constructed;

[0146] The concentration of the sprayed fertilizer solution is brought into the fertilizer solution concentration inversion prediction model to obtain the E of the fertilizer solution for this irrigation and fertilization. c The predicted value and pH value are compared with the E of the fertilizer solution after the start of fertilization. c The value or pH value is compared. If the comparison result exceeds the set threshold, a shutdown signal is issued and a shutdown report is generated. If the comparison result does not exceed the set threshold, the current irrigation and fertigation strategy will continue to be executed until the operating time of the sprinkler reaches the total time t of the sprinkler water-fertilizer integration operation, and this irrigation and fertigation ends.

[0147] See also Figures 4 to 8 The second aspect of the present invention provides a center support type sprinkler water and fertilizer integrated device, which mainly includes fertilizer equipment, a center support 3, a control system and a plurality of pipelines. The fertilizer equipment includes a fertilizer injection pump 1 and a fertilizer storage unit 2. The center support 3 includes a center support bracket 51 and a sprinkler main pipeline 52 located in the middle thereof.

[0148] like Figures 4 to 6 As shown, the fertilizer injection pump 1 adopts a plunger-type fertilizer injection pump, which is connected between the sprinkler main line 52 and the fertilizer storage unit 2 through a pipeline, and injects the fertilizer liquid in the fertilizer storage unit 2 into the sprinkler main line 52 according to the control command of the control system. Specifically, the inlet d1 of the fertilizer injection pump 1 is connected to the fertilizer outlet at the bottom of the fertilizer storage container 31 in the fertilizer storage unit 2 through the fertilizer suction pipeline 11, and a fertilizer suction filter 22 is installed on the fertilizer suction pipeline 11; the outlet d2 of the fertilizer injection pump 1 is connected to the sprinkler main line 52 through the fertilizer injection pipeline 12; the sprinkler main line 52 is connected to the inlet at the top of the fertilizer storage container 31 through the water replenishment pipeline 14, and a water replenishment filter 26 is installed on the water replenishment pipeline 14. A backwashing pipeline 13 is connected between the water replenishment pipeline 14 and the fertilizer suction pipeline 11. After each spraying of fertilizer liquid, the fertilizer injection pump 1 is flushed through the backwashing pipeline 13 to prevent the fertilizer liquid residue from damaging the fertilizer injection pump 1.

[0149] like Figure 6As shown, the fertilizer storage unit 2 of this embodiment is used to prepare fertilizer liquid of corresponding concentration according to the control command of the control system, and mainly includes a fertilizer storage container 31, an agitator, a fertilizer storage container top cover 34 and a fixed base frame 35. The fertilizer storage container 31 is specifically a fertilizer barrel, which is placed on the fixed base frame 35. The agitator is composed of a stirring motor 32 and a stirring impeller. The stirring motor 32 is installed on the top of the fertilizer storage container 31. The stirring impeller is located in the fertilizer storage container 31 and driven by the stirring motor 32. The stirring motor 32 drives the stirring impeller according to the control command of the control system to fully stir the water-fertilizer mixture in the fertilizer storage container 31. The fertilizer storage container top cover 34 is connected to the fertilizer storage container 31 through a thread.

[0150] like Figures 4 to 8 As shown, the control system includes a sensor unit, a valve group, and a first control cabinet 53 and a second control cabinet 54 suspended on one side of a central support bracket 51 and connected to each other. Among them:

[0151] The sensing unit includes a liquid level sensor 33 installed on the top of the fertilizer storage container 31, a pressure switch 29 installed on the fertilizer injection pipeline 12, and a flow meter 61, an E c The liquid level sensor 33 is used to collect the liquid level information in the fertilizer storage container 31 in real time; the pressure switch 29 is used to collect the internal pressure of the fertilizer injection pipeline 12 in real time; the flow meter 61 is located at the water inlet of the sprinkler main pipeline 52, which is used to collect the flow rate into the machine; the E installed downstream of the confluence of the fertilizer injection pipeline 12 and the sprinkler main pipeline 52 c Sensor 62 and pH sensor 63 are used to collect the pH of irrigation water before fertilization begins. c Value and pH value and E of the fertilizer solution sprayed during fertilization c value and pH value.

[0152] The valve group includes a water supply manual valve 28 and a water supply electric valve 27 installed on the water supply pipeline 14, a manual drain valve 36 installed at the bottom of the fertilizer storage container 31, a fertilizer suction manual valve 37 and a fertilizer suction electric valve 23 installed on the fertilizer suction pipeline 11, and the fertilizer suction manual valve 37 is arranged close to the manual drain valve 36, a fertilizer injection electric valve 24, a check valve 67 and a fertilizer injection manual valve 68 installed on the fertilizer injection pipeline 12, and the check valve 67 and the fertilizer injection manual valve 68 are arranged close to the sprinkler main pipeline 52, and a backwash electric valve 25 installed on the backwash pipeline 13;

[0153] See also Figure 8The first control cabinet 53 includes a percentage timer 66 and a first controller respectively arranged outside and inside the first cabinet; the second control cabinet 54 includes a frequency converter 64 and a second controller arranged inside the second cabinet, and a human-computer interaction unit 65 arranged outside the second cabinet, and the second controller integrates an irrigation and fertilization strategy generation module and an irrigation fertilizer concentration control module (the irrigation and fertilization strategy generation module and the irrigation fertilizer concentration control module are in Figure 8 (not shown), the first controller and the second controller communicate with each other wirelessly or by wire;

[0154] The human-machine interaction unit 65 includes a liquid crystal screen for allowing the user to set the fertilizer application amount per mu and the irrigation quota and fertilizer type for this irrigation and fertilization, and displaying the real-time working status of the water-fertilizer integration device of the center pivot sprinkler to the user;

[0155] The fertigation strategy generation module can calculate the working parameters of the sprinkler and the fertilizer injection pump according to the parameters set by the user and the inflow flow of the sprinkler collected by the flow meter 61 before the start of fertilizer injection, form the current fertigation strategy and transmit it to the human-computer interaction unit 65 for display;

[0156] The irrigation fertilizer concentration control module is used to monitor and adjust the concentration of the irrigation fertilizer during the irrigation process: select the corresponding fertilizer concentration inversion prediction model according to the fertilizer type, and use the E of the irrigation water before the start of fertilization c The water and fertilizer application information in the irrigation and fertigation process is inverted in real time by using the pH value and the water and fertilizer application information, and the water and fertilizer application information is combined with the E of the fertilizer liquid sprayed after the fertilization begins. c The value is compared with the pH value, and a control instruction is formed based on the comparison result. Specifically, if the comparison result exceeds the set threshold, the second controller communicates with the first controller, sends a shutdown signal to stop the current fertigation, and sends a report to the human-computer interaction unit. If the comparison result does not exceed the set threshold, the current fertigation strategy continues to be executed until the current fertigation ends.

[0157] The first controller is directly connected to the percentage timer 66, and is connected to the sprinkler water supply main pump locally or remotely, and is used to control the start and stop of the sprinkler, the running time and the start and stop of the sprinkler water supply main pump according to the current fertilization and irrigation strategy generated by the fertilization and irrigation strategy generation module, and control the travel speed of the sprinkler through the percentage timer 66;

[0158] The frequency converter 64 is controlled by the second controller and is directly connected to the fertilizer injection pump to change the speed of the fertilizer injection pump motor to achieve control of the flow rate of the fertilizer injection pump 1;

[0159] The second controller is directly connected to the valve group, the stirring motor in the fertilization equipment and the LCD screen in the human-computer interaction unit 65, and is linked to the sensor unit through the RS-485 serial bus standard. The second controller controls the operation of the fertilization equipment, the sensor unit and the valve group according to the current fertilization strategy generated by the fertilization strategy generation module and the control instructions generated by the irrigation fertilizer solution concentration control module.

[0160] The following describes the specific working process of a central pivot sprinkler irrigation machine water and fertilizer integration device provided by the second embodiment of the present invention:

[0161] 1) When the water-fertilizer integration device of the present embodiment is started and fertilizer is injected into the sprinkler main line 52, the fertilizer application amount M per mu and the irrigation quota h of this irrigation and fertilization should be input into the human-machine interaction unit 65, and the fertilizer type should be set. Then, the irrigation and fertilization strategy generation unit in the second control cabinet 54 can calculate the setting value of the sprinkler percentage timer, the working frequency of the plunger fertilizer injection pump, the total irrigation and fertilization time and other working parameters, form the irrigation and fertilization strategy for this time, and output it by the human-machine interaction unit 65.

[0162] 2) According to the current irrigation and fertilization strategy, the top cover 34 of the fertilizer storage container is opened and an appropriate amount of fertilizer is poured in. The main water supply pump of the center pivot sprinkler is started through the first controller in the first control cabinet 53 to fill the main pipeline 52 of the center pivot sprinkler with water. Then the second controller opens the water replenishment electric valve 27 to inject clean water into the fertilizer storage container 31 through the water replenishment pipeline 14. When the liquid level sensor 33 detects that the liquid level in the fertilizer storage container 31 reaches the set water level, the second controller issues a control command to close the water replenishment electric valve 27 and the first controller issues a control command to close the main water supply pump of the sprinkler. At the same time, the second controller turns on the stirring motor 32 to allow the fertilizer to fully dissolve in the fertilizer storage container 31.

[0163] 3) After the fertilizer is fully dissolved, the first controller starts the main water supply pump of the center pivot sprinkler to supply water to the main pipe 52 of the center pivot sprinkler. When the nozzle starts to spray water, the center pivot sprinkler starts to move according to the setting value of the percentage timer 66; at the same time, the plunger fertilizer pump 1 and the fertilizer suction electric valve 23 are turned on by the second controller, and the fully dissolved fertilizer liquid flows from the fertilizer storage container 31 through the fertilizer suction pipe 11 and enters the inlet d1 of the plunger fertilizer pump 1 after being filtered by the fertilizer suction filter 23. The fertilizer liquid at the outlet d2 of the plunger fertilizer pump 1 is then injected into the main pipe 52 of the sprinkler through the fertilizer injection pipe 12, and the center pivot sprinkler starts to spray the fertilizer liquid. During this period, the second controller controls the flow rate of the plunger fertilizer pump 1 through the frequency converter 64.

[0164] 4) When the liquid level sensor 33 detects that the liquid level in the fertilizer storage container 31 reaches the lower limit, the liquid level sensor 33 automatically sends a signal to the second controller, and the second controller closes the plunger fertilizer injection pump 1 and the fertilizer suction electric valve 23; after the plunger fertilizer injection pump 1 stops running, it is checked whether the running time of the fertilizer liquid spraying process has reached t f Determine whether this water and fertilizer process is finished. If not, repeat step 2) until the fertilizer liquid spraying process is finished. If the fertilizer liquid spraying process is finished, execute step 5).

[0165] 5) Start the backwashing and clean water irrigation process. For the backwashing process, the second controller opens the backwashing electric valve 25 and the plunger fertilizer injection pump 1. Clean water is filtered by the water supply filter 26 from the central pivot sprinkler main line 52, and then enters the inlet d1 of the plunger fertilizer injection pump 1 through the water supply line 14, the backwashing line 13 and the fertilizer suction line 11. The residual fertilizer liquid at the outlet d2 of the plunger fertilizer injection pump 1 is then injected into the sprinkler main line 52 by the fertilizer injection line 12 until the set backwashing time is reached, that is, the running time t of the fertilizer injection pump during the backwashing process c After that, the second controller closes the backwash electric valve 25 and the plunger fertilizer injection pump 1, and the backwash process ends; for the clean water irrigation process, the first controller controls the central pivot sprinkler to continue moving according to the running speed set by the irrigation and fertilization strategy, and the sprinkler starts to spray clean water until the irrigation process ends. The first controller controls the central pivot sprinkler water supply main pump to shut down and stops the central pivot sprinkler.

[0166] In addition, the present invention can monitor the fertilizer concentration of the central pivot sprinkler main line 52 in real time during the irrigation and fertilization process and perform feedback control; first, before the fertilizer injection process, the flow meter 61, E c The sensor 62 and the pH sensor 63 respectively measure the flow rate of the central pivot sprinkler main line 52 and the pH of the irrigation water. c and pH value; then, based on the fertilization strategy generated by the fertilization strategy generation unit, the concentration of the fertilizer solution sprayed by the center pivot sprinkler is calculated by the above formula, and the functional relationship between the corresponding fertilizer solution concentration, conductivity and pH value is selected by the preset fertilizer type to calculate the E of the fertilizer solution sprayed by the water-fertilizer integration strategy c Or pH value; finally, the calculated E c Or pH value and E measured during fertilizer injection c Or pH value is compared, if the difference between the two is greater than the set upper limit of the difference, the first controller and the second controller send a shutdown instruction to the devices controlled by each to stop the irrigation and fertilization process, and feedback prompts to the human-computer interaction unit 65.

[0167] In the above embodiment, the pressure switch 29 is used to monitor the internal pressure of the fertilizer injection pipeline 12 in real time and transmit it to the second controller. When the fertilizer injection pipeline 12 or the fertilizer injection pump 1 fails, causing the internal pressure to be greater than the maximum working pressure of the plunger fertilizer injection pump 1, the second controller sends a shutdown command to the plunger fertilizer injection pump 1 to prevent excessive outlet water pressure from damaging the plunger fertilizer injection pump 1 and the fertilizer injection pipeline 12, while avoiding the occurrence of safety accidents.

[0168] In the above embodiment, when the electric valve of the equipment fails, the integrated application of water and fertilizer can be achieved through the water injection manual valve 28 and manual control.

[0169] Example 1

[0170] This application example takes the use of integrated water-fertilizer topdressing during the greening-jointing period of winter wheat as an example:

[0171] The fertilizer used is potassium chloride, the application amount M per mu is 4kg, and the irrigation quota h is 30mm; the sensor measures the flow rate of the sprinkler to be 80m 3 / h, the EC value of irrigation water is 771.48μS / cm; 0.342 kg of potassium chloride can be dissolved in each liter of water at room temperature, then:

[0172] S=0.342kg / L

[0173] The length of the center pivot sprinkler is 208m, and the range of the sprinkler installed at the end of the sprinkler is 25m. The coverage area of ​​the center pivot sprinkler is:

[0174]

[0175] The total amount of fertilizer injected by the center pivot sprinkler can be expressed as:

[0176]

[0177] The volume of the fertilizer storage container in the fertilization equipment for this sprinkler irrigation is 2000L, so the number of fertilizer distribution times N is:

[0178]

[0179] Rounding up to get the number of fertilizer distribution N = 3 buckets, then the actual fertilizer injection amount V is:

[0180] V=NV t =3×2000=6000L

[0181] The distance between the center point of the center support of the sprinkler and the terminal tower vehicle is 194m, the rated speed of the drive motor is 1425r / min, the effective radius of the matching tire is 0.6325m, the drive motor reducer transmission ratio is 40:1, the wheel reducer transmission is 50:1, and the field surface slip coefficient is 0.95. The shortest operation time of the center support sprinkler in one week is:

[0182]

[0183] At this time, the wind speed is 2.5m / s, and the field spraying water utilization coefficient is 0.85. The setting value of the percentage timer of the center pivot sprinkler during the process of sprinkler irrigation is:

[0184]

[0185] Round down to get the percentage timer setting value x of the central pivot sprinkler during the fertilizer liquid sprinkler irrigation process f =31%.

[0186] The operating time of the sprinkler during the fertilizer liquid irrigation process is:

[0187]

[0188] After the fertilizer injection pump is calibrated, the actual flow rate of the fertilizer injection pump is 305.2L / h, so the working frequency of the plunger fertilizer injection pump is:

[0189]

[0190] Rounding up, the operating frequency of the plunger fertilizer pump in the fertilizer spraying process is f = 41Hz.

[0191] In the water-fertilizer integration operation of the sprinkler, the fertilizer liquid and the clean water should be considered in coordination. After each fertilizer liquid is sprinkled, a certain depth of clean water must be sprayed to meet the irrigation quota required by the crop and to clean the leaf surface. The clean water depth of this sprinkler irrigation is:

[0192] h w =hh f =30-10=20mm

[0193] The setting value of the percentage timer of the central pivot sprinkler during the sprinkler irrigation process is:

[0194]

[0195] Round down to get the percentage timer setting value x of the central pivot sprinkler during the fertilizer liquid sprinkler irrigation process w =15%.

[0196] The running time of the sprinkler machine during the sprinkler water cleaning process is:

[0197]

[0198] The total duration of the sprinkler irrigation and fertilization integration operation is:

[0199] t=t f +t w =24.35+50.33=74.68h

[0200] The concentration c of the fertilizer stock solution prepared in the fertilizer container during the process of the sprinkler spraying the fertilizer solution is:

[0201]

[0202] When the fertilization process begins, the potassium chloride fertilizer concentration of the water-fertilizer mixture in the main pipeline can be calculated as:

[0203]

[0204] The functional relationship between the potassium chloride fertilizer solution concentration and the conductivity built into the control system is as follows:

[0205] E c =aC s +b=2.2441×10 6 ×5.02×10 -4 +771.48=1898.02μS / cm

[0206] The upper limit of the difference between the calculated value and the measured value set this time is 10%. At this time, the EC sensor measures the conductivity E' of the water-fertilizer mixture in the irrigation main line of the center pivot sprinkler. C is 1983.39μS / cm, we can get:

[0207]

[0208] At this time, the water-fertilizer integrated device of the center pivot sprinkler is in normal working condition.

[0209] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0210] Although embodiments of the present disclosure have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for integrated water and fertilizer control of a center pivot sprinkler, characterized in that: Used to control the water-fertilizer integrated equipment of the central pivot sprinkler, the water-fertilizer integrated equipment of the central pivot sprinkler includes a central pivot sprinkler, a fertilizer injection pump and a fertilizer storage unit connected to each other, the control method includes: Obtain the inherent parameters of the sprinkler, and set the fertilizer application amount per mu, irrigation quota and fertilizer type for this irrigation and fertilization; Collect the inflow flow of the sprinkler and the E of the clean water in the sprinkler main line before the start of this fertilizer injection irrigation. c value or pH value; According to the inherent parameters of the sprinkler, the fertilizer application amount per mu, the irrigation quota and the fertilizer type of the current irrigation and fertilization, and the inflow flow rate, the working parameters of the sprinkler and the fertilizer injection pump are calculated to form the current irrigation and fertilization strategy, specifically, the strategy of first spraying fertilizer solution, then synchronously performing the backwashing process and spraying clean water; Control the central pivot sprinkler irrigation machine water and fertilizer integration equipment to execute the current irrigation and fertilization strategy; In the process of controlling the central pivot sprinkler irrigation machine water-fertilizer integrated equipment to execute the current irrigation and fertilization strategy, the concentration of the sprinkler fertilizer solution is monitored and feedback-adjusted: the corresponding fertilizer solution concentration inversion prediction model is selected according to the fertilizer type, and the E of the fertilizer solution sprayed for this irrigation and fertilization is obtained according to the spraying fertilizer solution concentration and the selected fertilizer solution concentration inversion prediction model. c The predicted value or pH predicted value is compared with the E of the sprayed fertilizer solution collected after the start of fertilization. c The water or pH value is compared, and the control instructions of the center pivot sprinkler water and fertilizer integration equipment are formed based on the comparison results.

2. The control method according to claim 1, characterized in that: The inherent parameters of the sprinkler include the overall length of the sprinkler, the range of the nozzle installed at the end of the sprinkler, the field spraying water utilization coefficient, the field surface slip coefficient, the rated speed of the drive motor, the effective radius of the matching tire, the drive motor reducer transmission ratio, the wheel reducer transmission ratio, the distance between the center point of the center support of the sprinkler and the end tower vehicle, the rated frequency of the fertilizer injection pump and the actual flow of the fertilizer injection pump after calibration.

3. The control method according to claim 1, characterized in that: The E c The pH value and the pH value are measured by an E installed downstream of the junction of the fertilizer injection pipeline and the sprinkler main pipeline. c The flow rate is collected by the sensor and the pH sensor, and the inflow flow is collected by the flow meter installed at the water inlet of the main pipeline of the sprinkler irrigation machine.

4. The control method according to claim 1, characterized in that: The fertigation strategy includes: Preset program: Determine the coverage area A0 of the sprinkler and the shortest operation time t of the sprinkler in one week according to the inherent parameters of the sprinkler min ; Sprinkler irrigation fertilizer solution: Determine the total fertilizer injection volume V of this sprinkler irrigation fertilizer solution based on the maximum solubility S of the given fertilizer at room temperature, the set fertilizer application rate M per mu, and the coverage area A0 of the sprinkler irrigation machine. f , and according to the total amount of fertilizer injected V f and the volume V of the fertilizer storage container in the fertilizer storage unit t Determine the actual amount of fertilizer V injected in this sprinkler irrigation; according to the sprinkler irrigation machine flow Q0, the set fertilizer depth h of the sprinkler irrigation process f , the coverage area A0 of the sprinkler and the shortest operation time t of the sprinkler in one week min , determine the setting value x of the percentage timer of the sprinkler during the fertilizer irrigation process f ; According to the shortest operation time of the sprinkler in a week t min and the setting value x of the percentage timer of the sprinkler during the fertilizer liquid irrigation process f , calculate the operating time t of the sprinkler during the fertilizer irrigation process f According to the actual amount of fertilizer V injected by the current sprinkler irrigation, the rated frequency f of the fertilizer injection pump d , the actual flow rate of the fertilizer injection pump after the verification q d and the operating time t of the sprinkler irrigation process f Determine the operating frequency f of the fertilizer injection pump; Backwash process: Set the running time of the fertilizer injection pump during the backwash process t c And the operating frequency f c ; Sprinkler irrigation water: according to the current irrigation quota h and the fertilizer liquid depth h during the sprinkler irrigation process f Calculate the irrigation depth h of sprinkler irrigation water w According to the inflow flow Q0 of the sprinkler, the coverage area A0 of the sprinkler, and the shortest operation time t of the sprinkler in one week min and the irrigation depth h of the sprinkler irrigation water w , determine the setting value x of the percentage timer of the sprinkler during the sprinkler irrigation process w ; According to the shortest operation time of the sprinkler in a week t min and the setting value x of the percentage timer of the sprinkler during the sprinkler irrigation process w , calculate the running time t of the sprinkler irrigation process w , and t w >t c ; According to the operation time t of the sprinkler irrigation process f and the operating frequency f of the fertilizer injection pump, the operating time t of the fertilizer injection pump during the backwashing process c And the working frequency f of the fertilizer injection pump c The running time of the sprinkler irrigation machine during the sprinkler irrigation water cleaning process is t w , and the total duration of the sprinkler irrigation and fertilization integration operation t=t f +t w The irrigation and fertilization strategy is formed.

5. The control method according to claim 4, characterized in that: The coverage area A0 of the sprinkler is calculated according to the following formula: Where, L s is the length of the sprinkler; R is the range of the sprinkler installed at the end of the sprinkler; The shortest operation time of the sprinkler in a week is t min , calculated according to the following formula: Where, L f is the distance between the center point of the central support of the sprinkler and the terminal tower vehicle; i1 is the transmission ratio of the drive motor reducer; i2 is the transmission ratio of the wheel reducer; n is the rated speed of the drive motor; r is the effective radius of the matching tire; η is the field surface slip coefficient, which depends on the tire pattern, tire pressure and soil compactness, and is taken as 0.92~0.97; The total amount of fertilizer injected by the sprinkler this time is V f , calculated according to the following formula: In the formula, k is the coefficient set to ensure that the fertilizer is fully dissolved, which is set to 1.3-1.6; The actual injection amount V of the fertilizer solution for this sprinkler irrigation is calculated according to the following formula: V=NV t In the formula, N is the number of times the fertilizer solution is dispensed for this irrigation. The N value obtained by the above formula is rounded up as the number of times the fertilizer solution is dispensed for this irrigation. The setting value x of the percentage timer of the sprinkler during the fertilizer liquid irrigation process f , calculated according to the following formula and rounded down to get: Where η p is the field spraying water utilization coefficient, which is related to the wind speed. When the wind speed is lower than 3.4 m / s, η p Take 0.8~0.9, when the wind speed is 3.4~5.4m / s, η p Take 0.7~0.8; the fertilizer liquid depth h in the process of sprinkler irrigation f The value shall not be less than 5mm; The operating time of the sprinkler during the fertilizer liquid irrigation process is t f , calculated according to the following formula: The operating frequency f of the fertilizer injection pump is calculated according to the following formula: The irrigation depth of the sprinkler irrigation water is h w , calculated according to the following formula: h w =h-h f The setting value x of the percentage timer of the sprinkler during the sprinkler irrigation process w , calculated according to the following formula and rounded down to get: The running time of the sprinkler irrigation machine during the sprinkler irrigation water cleaning process is t w , calculated according to the following formula: Where, t min The minimum time the pivot machine runs in a week.

6. The control method according to claim 1, characterized in that: In the process of controlling the central pivot sprinkler irrigation machine water-fertilizer integrated equipment to execute the current irrigation and fertilization strategy, the fertilizer solution concentration is monitored and feedback-regulated, specifically including: The concentration of the fertilizer stock solution configured in the fertilizer liquid container of the fertilizer storage unit during the process of the central pivot sprinkler irrigation is calculated according to the following formula: In the formula, C is the concentration of the original fertilizer solution; M is the amount of fertilizer applied per mu; A0 is the coverage area of ​​the sprinkler; V is the actual amount of fertilizer injected in this sprinkler irrigation; According to the sprinkler machine inlet flow Q0, the actual flow of the fertilizer pump after verification q d The concentration of the sprinkler fertilizer solution is calculated based on the concentration of the configured fertilizer stock solution, and the calculation formula is as follows: In the formula, C s is the concentration of fertilizer solution for sprinkler irrigation; According to the fertilizer type, the corresponding fertilizer solution concentration inversion prediction model is selected. The fertilizer solution concentration inversion prediction model is used to reflect the sprinkler irrigation fertilizer solution concentration and the E c The functional relationship between the value or pH value; The concentration of the sprayed fertilizer solution C s The fertilizer concentration inversion prediction model is introduced to obtain the E of the fertilizer solution for this irrigation and fertilization sprinkler irrigation. c The predicted value and pH value are compared with the E of the fertilizer solution sprayed after the fertilization begins. c The value or pH value is compared. If the comparison result exceeds the set threshold, a shutdown signal is issued and a shutdown report is generated. If the comparison result does not exceed the set threshold, the current fertigation strategy will continue to be executed until the operating time of the sprinkler reaches the total time of the sprinkler water-fertilizer integration operation, and this fertigation ends.

7. The control method according to claim 6, characterized in that: When strong electrolytes are used as fertilizers, the inversion prediction model for fertilizer solution concentration is: E c =aC s +b In the formula, E c is the conductivity; a is the first coefficient, which needs to be calibrated through experiments; b is the E of the irrigation water before the start of fertilizer injection c value; When acidic or alkaline fertilizer is used as fertilizer, the inversion prediction model of fertilizer solution concentration is: pH=yC s +z In the formula, pH is acidity and alkalinity; y is the second coefficient, which needs to be calibrated through experiments; z is the pH value of irrigation water before fertilization begins.

8. A central pivot sprinkler irrigation machine water and fertilizer integration device based on the control method according to any one of claims 1 to 7, characterized in that: It includes a fertilizing device, a central support, a control system and several pipelines. The fertilizing device includes a fertilizer injection pump and a fertilizer storage unit. The central support includes a central support bracket and a sprinkler main pipeline located in the middle. The fertilizer injection pump is connected between the sprinkler main line and the fertilizer storage unit through a pipeline, and injects the fertilizer liquid in the fertilizer storage unit into the sprinkler main line according to the control instruction of the control system; wherein the inlet of the fertilizer injection pump is connected to the fertilizer outlet at the bottom of the fertilizer storage container in the fertilizer storage unit through a fertilizer suction pipeline; the outlet of the fertilizer injection pump is connected to the sprinkler main line through the fertilizer injection pipeline; the sprinkler main line is connected to the inlet of the fertilizer storage container through a water supply pipeline, and a backwash pipeline is connected between the water supply pipeline and the fertilizer suction pipeline, and the fertilizer injection pump is flushed through the backwash pipeline after each spraying of fertilizer liquid. The fertilizer storage unit is used to prepare fertilizer solution of corresponding concentration according to the control instruction of the control system, and the fertilizer storage unit includes the connected fertilizer storage container and the agitator; The control system includes a sensor unit, a valve group, and a first control cabinet and a second control cabinet which are arranged on one side of the core support bracket and communicate with each other; wherein, The sensing unit includes a liquid level sensor installed on the top of the fertilizer storage container, a pressure switch installed on the fertilizer injection pipeline, and a flow meter, an E c Sensors and pH sensors; The valve group includes a water replenishment electric valve, a fertilizer suction electric valve, a fertilizer injection electric valve, and a backwashing electric valve, which are respectively installed on corresponding pipelines; The second control cabinet is used to calculate the working parameters of the sprinkler and the fertilizer injection pump according to the parameters set by the user and the inflow flow of the sprinkler collected by the flow meter before the start of fertilizer injection, form the current irrigation and fertilization strategy and display it to the user; control the operation of the fertilization equipment, the sensor unit and the valve group according to the current irrigation and fertilization strategy, and monitor and feedback-adjust the concentration of the sprinkler fertilizer solution during the control process; The first control cabinet is used to control the start and stop, travel speed and running time of the sprinkler, and the start and stop of the main water supply pump of the sprinkler according to the current irrigation and fertilization strategy.

9. The device according to claim 8, characterized in that The fertilizer suction pipeline is also equipped with a fertilizer suction filter and a fertilizer suction manual valve, the water replenishment pipeline is also equipped with a water replenishment filter and a water replenishment manual valve, the fertilizer injection pipeline is also equipped with a check valve and a fertilizer injection manual valve, and a manual drain valve is installed at the bottom of the fertilizer storage container.

10. The device according to claim 8, characterized in that The second control cabinet includes a frequency converter and a second controller arranged inside the second cabinet, and a human-computer interaction unit arranged outside the second cabinet. The second controller integrates an irrigation and fertilization strategy generation module and an irrigation fertilizer liquid concentration control module. The second controller controls the working frequency of the fertilizer injection pump through the frequency converter. The second controller is connected to the sensor unit, the valve group and the agitator. The first control cabinet includes a percentage timer and a first controller respectively arranged outside and inside the first cabinet. The first controller communicates with the second controller, and the first controller controls the travel speed of the sprinkler through the percentage timer.

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