Method and system for flow correction and fault early warning of water and fertilizer all-in-one machine

Abstract

The invention discloses a method and a system for flow correction and fault early warning of a water and fertilizer all-in-one machine. The method comprises the following steps: acquiring flow data acquired by a Hall flowmeter; acquiring liquid level data acquired by a liquid level sensor; the actual fertilization volume is calculated according to liquid level data collected by the liquid level sensor, and the flow pulse parameter of the Hall flowmeter is corrected based on the actual fertilization volume; contrastive analysis is performed according to the actual fertilization volume of a single fertilizer barrel and the theoretical fertilization amount corresponding to the fertilizer barrel, whether the difference value of the two exceeds a set threshold value or not is judged, and if yes, fertilization precision low fault early warning is given; comparing the actual fertilization volumes of the various fertilizer barrels to judge whether the proportions of the application amounts of the various fertilizers are balanced or not, and if not, giving out an imbalance early warning of the application amounts. According to the invention, a multi-sensor fusion technology is adopted, and the flow pulse parameters of the Hall flowmeter can be corrected. In addition, fault early warning can be carried out on the fertilization amount accuracy of a single fertilizer barrel, and fault early warning can also be carried out on the fertilization balance of multiple fertilizer barrels.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural intelligent irrigation equipment, and in particular to a method and system for flow correction and fault warning of a water-fertilizer integrated machine. Background Art

[0002] Integrated water-fertilizer technology is the key supporting technology for achieving precise fertilization in facility agriculture. It has been widely used in facility agriculture at this stage. The realization of precise water-fertilizer integration is inseparable from the accurate detection of the flow rate of the fertilizer liquid, especially the volume of fertilizer.

[0003] In facility agriculture, integrated water and fertilizer machines are required. According to the characteristics of the planting soil and the growth law of crops, irrigation equipment is used to accurately and quantitatively supply water and nutrients to crops at the same time. To achieve the purpose of precise quantitative fertilization, accurate detection of the amount of fertilizer applied is the key. At present, most integrated water and fertilizer machines use Hall flow meters for flow and fertilizer amount detection because of their low price and wide detection range.

[0004] However, in the field of water and fertilizer irrigation, due to the complex and special application scenarios, the key detection parameters of the Hall flowmeter vary greatly compared with the factory due to the coupling of multiple factors such as bubbles and large particles in the fertilizer liquid, the presence of two-phase flow, installation stress and position, fertilizer pump speed, vibration source, viscosity of the flowing medium and pipeline pressure, and so on. The key detection parameters need to be calibrated in specific application scenarios. In addition, affected by multiple coupling factors, the Hall flowmeter cannot maintain accuracy for a long time, resulting in more or less fertilizer application, and even leading to a large difference in the liquid level between the fertilizer barrels after a period of fertilization when the fertilizer application amount and the fertilizer barrel are the same and the initial liquid level is the same. This will lead to more or less nutrients applied to the crops, affecting the quality of the product. In order to be suitable for water and fertilizer irrigation application scenarios and accurately detect the amount of fertilizer liquid applied, the flow pulse parameter value of the key parameter of the flowmeter needs to be calibrated regularly. In addition, in order to achieve intelligent fertilization and evaluate whether the amount of fertilizer liquid applied is accurate and balanced, it is also necessary to warn of faults that occur during fertilization.

[0005] In the prior art, patent CN 215269854 U discloses a multi-terminal monitoring integrated water, fertilizer and gas drip irrigation system, in which a liquid level sensor is provided in the water storage tank, and a solenoid valve and a flow meter are provided on the water supply pipe. In this patent, the liquid level sensor and the flow meter work independently, and the liquid level sensor is used to monitor the amount of water in the water storage tank. The controller replenishes water in time based on the liquid level data collected by the liquid level sensor, and the flow meter is used to monitor the irrigation flow. In this patent, the liquid level sensor and the flow meter will each produce a metering error. The flow meter will cause a metering error due to various factors such as bubbles, pipeline pressure, and vibration, and the liquid level sensor will cause inaccurate metering due to factors such as liquid surface shaking and vibration. Other prior arts such as CN 108323295A also use similar control methods and have the same technical defects. Summary of the invention

[0006] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a method and system for flow correction and fault warning of a water-fertilizer integrated machine.

[0007] Technical solution: To achieve the above purpose, the method for flow correction and fault warning of a water-fertilizer integrated machine of the present invention comprises:

[0008] Obtain the flow data collected by the Hall flow meter and calculate the amount of fertilizer based on it;

[0009] Acquire liquid level data collected by the liquid level sensor;

[0010] The liquid level sensor performs data collection when the water-fertilizer integrated machine is stopped and not in operation, and the method further includes:

[0011] Calculating the actual fertilization volume according to the liquid level data collected by the liquid level sensor, and correcting the flow pulse parameter of the Hall flowmeter based on the actual fertilization volume;

[0012] Compare and analyze the actual fertilizer volume of a single fertilizer bucket with the theoretical fertilizer volume corresponding to the fertilizer bucket to determine whether the difference between the two exceeds the set threshold. If so, a low fertilization accuracy fault warning is given;

[0013] Compare the actual fertilizer volumes of various fertilizer barrels to determine whether the application ratios of the various fertilizers are balanced. Otherwise, give an early warning of unbalanced application.

[0014] Further, the obtaining of liquid level data collected by the liquid level sensor includes:

[0015] Determine whether the preset key sampling time node has been reached, and if so, continue to execute subsequent steps;

[0016] The liquid level sensor is used to collect real-time liquid level data at fixed time intervals, and the real-time liquid level data collected multiple times are cached into an array;

[0017] The array is verified by a first-level data straight line smoothness filtering algorithm to obtain a valid array that meets preset requirements;

[0018] The effective array is processed by a second median average filtering algorithm to obtain the liquid level data.

[0019] Furthermore, the array is verified by the first data straight line smoothness filtering algorithm to obtain a valid array that meets preset requirements, including:

[0020] Adjacent data difference processing is performed on the values ​​in the array, and statistical analysis is performed to determine whether each difference calculated is less than a set threshold. If so, the cached array is considered valid and is used as the valid array.

[0021] Furthermore, the performing of a second median average filtering algorithm on the effective array to obtain the liquid level data specifically includes:

[0022] Sorting the data in the valid array in ascending order;

[0023] According to the preset filter window size, the middle part of the sorted data is intercepted;

[0024] The data in the filtering window is averaged, and the average processing is performed based on the following formula:

[0025] y=average(x [(m-k) / 2] ,…,x [(m+k) / 2-1] );

[0026] Among them, y is the output result of the filtering algorithm; m is an even number, representing the total number of sampling points; k is an even number, representing the size of the filtering window; x [(m-k) / 2] ,…,x [(m+k) / 2-1] The window sampling values ​​are selected after the original array is sorted from small to large.

[0027] Furthermore, the liquid level sensor is a non-contact millimeter wave radar liquid level sensor, which is installed at the middle position of the top of the fertilizer barrel, and the liquid level data is the distance value between the probe of the non-contact millimeter wave radar liquid level sensor and the liquid surface; the actual fertilization volume is calculated according to the liquid level data collected by the liquid level sensor, and the flow pulse parameter of the Hall flowmeter is corrected based on the actual fertilization volume, including:

[0028] The fertilizer amount is calculated based on the first reflection height h1 measured at the previous key sampling time node and the second reflection height h2 measured at the current key sampling time node. The calculation formula is as follows:

[0029] V=S*△h=π*r 2 *(h2-h1);

[0030] Among them, V is the amount of fertilizer applied during the fertilization cycle between two key sampling time nodes, in L; S is the cross-sectional area of ​​the cylindrical fertilizer barrel, in mm 2 ; △h is the change in liquid level in the fertilizer bucket before and after fertilization in one day, unit is mm; r is the radius of the fertilizer bucket, unit is mm;

[0031] The flow pulse parameters are calculated based on the following formula:

[0032] Q = N / V;

[0033] Among them, N is the total number of pulses output by the Hall flowmeter during the fertilization process, and Q is the calibrated flow pulse parameter value of the flowmeter.

[0034] Furthermore, the actual fertilizer application volumes of the various fertilizer barrels are compared to determine whether the application ratios of the various fertilizers are balanced, and if not, an early warning of imbalanced application is given, including:

[0035] Compare the actual fertilizer volumes of all fertilizer buckets after a single fertilization cycle is completed, and determine whether the converted difference between the actual fertilizer volumes corresponding to the fertilizer buckets exceeds a preset threshold. If so, give a short-term warning of uneven fertilizer application between fertilizer routes;

[0036] The actual total volume of fertilizer applied by all fertilizer buckets after multiple fertilization cycles is compared to determine whether the converted difference between the actual total volume of fertilizer applied by each fertilizer bucket exceeds a preset threshold. If so, a warning of long-term imbalance in fertilizer application between routes is given.

[0037] Furthermore, the method further comprises:

[0038] After the fertilizer adding operation for the fertilizer barrel is completed, the preset time is extended, and the step of collecting the liquid level data using the liquid level sensor is implemented to obtain the latest liquid level data as the initial liquid level data for subsequent calculations.

[0039] A system for flow correction and fault warning of a water-fertilizer integrated machine, the system comprising:

[0040] Multiple fertilizer buckets;

[0041] A fertilizer liquid pipeline, a flow regulating valve, a Hall flow meter and a liquid level sensor are arranged corresponding to each of the fertilizer barrels;

[0042] A main control board, all the flow regulating valves, the Hall flowmeter and the liquid level sensor are connected to the main control board, and the main control board can implement the above-mentioned method for flow correction and fault warning of the water-fertilizer integrated machine;

[0043] The power module is used to supply power to each power consumption unit.

[0044] Furthermore, the Hall flowmeter outputs a pulse signal, which is modulated by an optical coupling isolation input circuit and then input to the main control board.

[0045] Furthermore, the main control board is connected to a touch screen.

[0046] Beneficial effects: The method and system for flow correction and fault warning of the water-fertilizer integrated machine of the present invention have the following beneficial effects:

[0047] (1) By adopting multi-sensor fusion technology, the fertilizer volume can be calculated from the perspective of the overall fertilization of the system when the machine is stopped, and the amount of fertilizer can be detected more accurately. Based on this, the flow pulse parameters of the Hall flow meter can be corrected, which can effectively improve the accuracy of subsequent water and fertilizer application.

[0048] (2) Based on the actual fertilizer volume of a single fertilizer bucket, it is possible to determine whether the accuracy of the application of a single fertilizer meets the requirements, and based on the actual fertilizer volume of multiple fertilizer buckets, it is possible to determine whether the balance of the application of multiple water and fertilizers meets the requirements.

[0049] (3) The ultrasonic level sensor is used to measure the level change of the fertilizer liquid. It has the advantages of small measurement angle and measurement blind area. Compared with the traditional immersion level sensor, the ultrasonic level sensor does not contact the water and fertilizer and is not corroded. It is suitable for measuring fertilizer liquids of different concentrations and has good universality. Compared with the laser ranging sensor, the ultrasonic level sensor is more suitable for measuring the liquid level height and has a low price.

[0050] (4) The array data collected by the liquid level sensor is processed by a double filtering algorithm, which can effectively eliminate the influence of data fluctuations on the results and ensure the accuracy of the final liquid level data.

[0051] (5) When multiple fertilizers are applied together, the flow correction and fault warning algorithms are independent of the initial liquid level of the fertilizer barrels corresponding to each fertilizer, and do not require the liquid level heights of each fertilizer barrel to be the same. They are only related to the change in the liquid level of a single parameter, and the system design method does not require multiple parameters for judgment and analysis.

[0052] (6) Taking advantage of the characteristics of facility crop fertilization and irrigation, the key sampling time node method is adopted. When the liquid level does not fluctuate at night and the machine is not running for fertilization and irrigation, the distance between the sensor probe and the liquid level is detected. This can reduce the influence of liquid level fluctuations and electromagnetic interference and vibration during machine operation on data detection accuracy, ensure the accuracy and stability of the detection data, and the design method is ingenious and practical.

[0053] (7) After the warning of uneven application of multiple fertilizers is issued, compensation plans can be formulated for the short-term and long-term differences in fertilizer application. When the compensation data is large, the compensation can be evenly distributed over multiple subsequent fertilization cycles as needed to ensure the accuracy of the application of multiple fertilizers and avoid negative effects caused by excessive short-term compensation when the compensation data is large. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a schematic diagram of the composition of the system for flow correction and fault warning of the integrated water and fertilizer machine;

[0055] Figure 2 It is a schematic diagram of the connections between the components in the system;

[0056] Figure 3 It is a schematic diagram of the combination of the liquid level sensor and the fertilizer bucket;

[0057] Figure 4 A flow chart of a method for flow correction and fault warning of a water-fertilizer integrated machine;

[0058] Figure 5 It is a specific flow chart of the flow correction method;

[0059] Figure 6 Schematic diagram of the specific process of the fault warning method.

[0060] In the figure: 1. Fertilizer barrel; 2. Fertilizer liquid pipeline; 3. Flow control valve; 4. First signal line; 5. Liquid level sensor; 6, 7. Liquid level sensor fixing connector; 8, 9. Screws; 10. Second signal line; 11. Third signal line; 12. Hall flowmeter; 13. Control box; 14. Touch screen; 15. Antenna of remote communication transmission module. DETAILED DESCRIPTION

[0061] The present invention will be further described below in conjunction with the accompanying drawings.

[0062] The method for flow correction and fault warning of the water-fertilizer integrated machine of the present invention is based on the following Figure 1 The system implementation shown includes:

[0063] A plurality of fertilizer barrels 1; the figure shows three fertilizer barrels 1, corresponding to three types of fertilizers A, B, and C respectively;

[0064] A fertilizer liquid pipeline 2, a flow regulating valve 3, a Hall flowmeter 12 and a liquid level sensor 5 are provided corresponding to each of the fertilizer barrels 1; the liquid level sensor 5 is connected to the top of the fertilizer barrel 1 through the liquid level sensor 5 fixing connectors 6 and 7, and the liquid level sensor 5 fixing connectors 6 and 7 are fixed relative to the fertilizer barrel 1 through screws 8 and 9 respectively;

[0065] The main control board is installed in the control box 13. All the flow regulating valves 3, the Hall flowmeter 12 and the liquid level sensor 5 are connected to the main control board. The main control board can implement the above-mentioned method for flow correction and fault warning of the water-fertilizer integrated machine; specifically, the flow regulating valve 3 is connected to the main control board through the first signal line 4, the liquid level sensor 5 is connected to the main control board through the second signal line 10, and the Hall flowmeter 12 is connected to the main control board through the third signal line 11. Figure 2 As shown, the main control board includes a crystal oscillator circuit, an optical coupling isolation input circuit and an MCU main control unit, wherein the communication mode between the liquid level sensor 5 and the main control board of the integrated water and fertilizer machine is RS485, and the main control board of the integrated water and fertilizer machine in the RS485 bus communication network is the host, and the liquid level sensor 5 is the slave, and the communication protocol mode between the two is Modbus-RTU; after the liquid level sensor 5 measures the height data of its probe from the liquid surface, that is, the real-time liquid level data, it is filtered by an intelligent algorithm and stored locally, and after the host sends a read command at an interval of a certain time, the slave packages the liquid level data in a certain protocol format and sends it to the host; the Hall flowmeter 12 outputs a pulse signal, which is modulated by the optical coupling isolation input circuit of the main control board and input into the MCU main control unit of the main control board, and the MCU main control unit detects the number of pulses output by the Hall flowmeter 12 within 1 day (that is, within the fertilization cycle between two key sampling time nodes) accordingly;

[0066] A power module, which is used to supply power to each power-consuming unit, wherein the power-consuming unit includes a main control board, a Hall flow meter 12, a liquid level sensor 5, and a flow control valve 3;

[0067] A touch screen 14 is installed on the control box 13 and connected to the main control board. The user can send instructions to the main control board, modify parameters and obtain information through the touch screen 14;

[0068] The antenna 15 of the remote communication transmission module is connected to the main control board.

[0069] Based on the above system, Figure 6 The method for flow correction and fault warning of the integrated water and fertilizer machine shown includes the following steps S101-S102:

[0070] Step S101, obtaining flow data collected by the Hall flow meter, and calculating the amount of fertilizer applied based on the data;

[0071] Step S102, obtaining liquid level data collected by the liquid level sensor;

[0072] The liquid level sensor performs data collection when the water-fertilizer integrated machine is stopped and not in operation, and the method further includes the following steps S103-S105:

[0073] Step S103, calculating the actual fertilization volume according to the liquid level data collected by the liquid level sensor, and correcting the flow pulse parameter of the Hall flowmeter based on the actual fertilization volume; the flow pulse parameter refers to the number of pulses generated when one liter of liquid flows through the Hall flowmeter; in the next fertilization cycle implemented after the shutdown, the fertilization flow is calculated based on the corrected flow pulse parameter;

[0074] Step S104, comparing and analyzing the actual fertilizer volume of a single fertilizer bucket with the theoretical fertilizer amount corresponding to the fertilizer bucket, judging whether the difference between the two exceeds a set threshold, and giving a low fertilization accuracy fault warning if it does; in this way, it can be judged whether the fertilizer amount in the fertilization cycle between two adjacent shutdowns meets the requirements;

[0075] Step S105, comparing the actual fertilizer volumes of the various fertilizer barrels, and judging whether the application ratios of the various fertilizers are balanced, otherwise giving an early warning of imbalanced application.

[0076] In the above method, based on the use of liquid level sensors to collect liquid level data in the shutdown state, on the one hand, the multi-sensor fusion technology is used to measure the fertilizer volume from the perspective of the overall fertilization of the system when the machine is shut down, which can accurately detect the amount of fertilizer, and based on this, the flow pulse parameters of the Hall flowmeter are corrected, which can effectively improve the accuracy of subsequent water and fertilizer application. On the other hand, the above method can judge whether the accuracy of the application of a single fertilizer meets the requirements based on the actual fertilizer volume of a single fertilizer bucket, and can judge whether the application balance of multiple water and fertilizers meets the requirements based on the actual fertilizer volume of multiple fertilizer buckets. Based on this, it is possible to complete multi-sensor fusion calibration, single fertilizer application amount accuracy fault warning, and fertilization imbalance warning between multiple fertilizer buckets, and ensure the accuracy of fertilization in all directions.

[0077] Preferably, the step S102 of acquiring the liquid level data collected by the liquid level sensor comprises the following steps S201-S202:

[0078] Step S201, determine whether the preset key sampling time node is reached, and if yes, continue to execute the subsequent steps;

[0079] Step S202, using the liquid level sensor to collect real-time liquid level data every fixed time period, such as 500 ms, and caching the real-time liquid level data collected multiple times into an array;

[0080] Step S203, verifying the array using a first-level data line smoothness filtering algorithm to obtain a valid array that meets preset requirements;

[0081] Step S204, performing a second median average filtering algorithm process on the effective array to obtain the liquid level data.

[0082] In this embodiment, 12 o'clock in the morning is selected as the key sampling time node. At this time, since the machine is stopped, it will not be affected by the strong electromagnetic interference and vibration caused by inductive loads such as water pumps, AC contactors and solenoid valves when the water-fertilizer integrated machine is working. Such factors can effectively avoid the influence of water wave vibration and electromagnetic interference on the accuracy of the test results and reduce the calculation time for obtaining valid data.

[0083] At the key sampling time node of 12:00 a.m. at night, the liquid level data obtained after double filtering is used as the initial value for fertilization the next day. After the fertilization is completed on the day, the distance between the ultrasonic liquid level sensor probe and the liquid surface is detected at the key sampling time node of 12:00 a.m. at night according to the above method, and this value is also used as the initial distance value for fertilization the next day. The difference between the two distance values ​​is the liquid level difference of the fertilizer barrel on that day. The amount of fertilizer applied on that day can be calculated based on the liquid level difference. Figure 5 Shown is a process diagram of a complete flow calibration process.

[0084] Preferably, in the above step S203, the verification process of the array by using the first layer of data straight line smoothness filtering algorithm to obtain a valid array that meets the preset requirements includes:

[0085] Adjacent data difference processing is performed on the values ​​in the array, and statistical analysis is performed to determine whether each difference calculated is less than a set threshold. If so, the cached array is considered valid and is used as the valid array.

[0086] In actual operation, the data in the array can be set to a fixed number n, and the difference between adjacent data can be calculated in real time when the data in the array reaches n. When a difference greater than the set threshold occurs, one approach is to exclude these n real-time liquid level data, and re-add the latest real-time liquid level data, and continue to calculate until n-1 consecutive differences are obtained that are all less than the set threshold, then the cached array is considered valid; another approach is that when a difference greater than the set threshold occurs, the real-time liquid level data corresponding to the difference greater than the set threshold and the real-time liquid level data before it are deleted from the array, and the corresponding number of latest real-time liquid level data are added to obtain a new array, and the calculation is continued based on the new array until n-1 consecutive differences are obtained that are less than the set threshold, then the cached array is considered valid. The latter approach can retain part of the useful data in the array and improve calculation efficiency. The difference judgment condition for adjacent real-time liquid level data can be expressed as: |x i -x i+1 |<△L, where x i is the sampling value, i is a sampling sequence based on time, and its value is 0, 1,…, n-1; △L is the set threshold.

[0087] Preferably, the second median average filtering algorithm is performed on the effective array in the above step S204 to obtain the liquid level data, which specifically includes the following steps S301-S303:

[0088] Step S301, sorting the data in the valid array in ascending order;

[0089] Step S302, intercepting the middle part of the sorted data according to a preset filter window size;

[0090] Step S303, performing average processing on the data in the filtering window, and the average processing is performed based on the following formula:

[0091] y=average(x [(m-k) / 2] ,…,x [(m+k) / 2-1] );

[0092] Among them, y is the output result of the filtering algorithm; m is an even number, representing the total number of sampling points; k is an even number, representing the size of the filtering window; x [(m-k) / 2] ,…,x [(m+k) / 2-1] The window sampling values ​​are selected after the original array is sorted from small to large.

[0093] In the above method, after the double filtering algorithm, the influence of data fluctuation on the result can be effectively eliminated, thereby ensuring the accuracy of the final liquid level data.

[0094] Preferably, the liquid level sensor is a non-contact millimeter wave radar liquid level sensor, which is installed in the middle of the top of the fertilizer barrel. The real-time liquid level data is the reflection height distance between the radar transmitter head of the millimeter wave radar liquid level sensor and the liquid surface in the fertilizer barrel. The above step S103 calculates the actual fertilization volume according to the liquid level data collected by the liquid level sensor, and corrects the flow pulse parameters of the Hall flowmeter based on the actual fertilization volume, including the following steps S401-S402:

[0095] Step S401, calculating the fertilizer amount based on the first reflection height h1 measured at the previous key sampling time node and the second reflection height h2 measured at the current key sampling time node, the calculation formula is as follows:

[0096] V=S*△h=π*r 2 *(h2-h1);

[0097] Where V is the amount of fertilizer applied during the fertilization cycle between two key sampling time nodes, in L;

[0098] S is the cross-sectional area of ​​the cylindrical fertilizer barrel, in mm 2 ;like Figure 3 As shown, △h is the change in the liquid level of the fertilizer bucket before and after fertilization in one day, in mm; r is the radius of the fertilizer bucket, in mm; the first reflection height h1 and the second reflection height h2 are both data obtained through the above double filtering process;

[0099] Step S402, calculating the flow pulse parameter based on the following formula:

[0100] Q = N / V;

[0101] Among them, N is the total number of pulses output by the Hall flowmeter during the fertilization process, and Q is the calibrated flow pulse parameter value of the flowmeter.

[0102] The non-contact millimeter wave radar level sensor (hereinafter referred to as ultrasonic level sensor) is used to measure the level change of fertilizer liquid. It has the advantages of small measurement angle and measurement blind area. Compared with the traditional immersion level sensor, the ultrasonic level sensor does not contact the water and fertilizer and is not corroded. Compared with the laser ranging sensor, the ultrasonic level sensor is more suitable for measuring the liquid level height and has a low price. Although the laser ranging sensor has high measurement accuracy for solid targets, when measuring liquids, the refraction and reflection of light will cause the propagation path of the light beam in the liquid to deviate, resulting in measurement errors and inaccurate measurement results.

[0103] Preferably, the actual fertilization volumes of the various fertilizer barrels are compared in the above step S105 to determine whether the application ratios of the various fertilizers are balanced, and if not, an application imbalance warning is given, including:

[0104] The actual fertilizer volumes of all fertilizer buckets after a single fertilization cycle are compared to determine whether the converted difference between the actual fertilizer volumes corresponding to the fertilizer buckets exceeds a preset threshold. If so, a short-term fertilizer application imbalance warning is given; here, when the target fertilizer volumes corresponding to the fertilizer buckets are the same, the difference between the corresponding actual fertilizer volumes is directly calculated; when the target fertilizer volumes corresponding to the fertilizer buckets are different, the actual fertilizer volumes are normalized and converted in proportion to the target fertilizer volumes, and then the difference is calculated;

[0105] After multiple fertilization cycles are completed, the actual total volume of fertilizer applied by all fertilizer buckets is compared to determine whether the converted difference between the actual total volume of fertilizer applied by each fertilizer bucket exceeds the preset threshold. If so, a warning of long-term imbalance in fertilizer application between fertilizer paths is given. In actual use, a single fertilization cycle is generally a fertilization operation for one day, and multiple fertilization cycles are fertilization operations for multiple days. For example, the actual total volume of fertilizer applied by each fertilizer bucket is counted once every 10 days, and a long-term fertilization comparison is performed to determine whether there is imbalance.

[0106] like Figure 6 The flowchart of a complete fault warning process in this embodiment is shown. Through the above method, when multiple fertilizers are applied at the same time, the balance of various water and fertilizer application can be ensured, and the nutrient elements applied to the crops will not be too much or too little due to short-term fertilization errors or long-term cumulative errors.

[0107] Preferably, after giving a short-term warning of uneven fertilizer application between fertilizer paths, the main control board can give a correction plan, specifically, adjust the target fertilizer application amount corresponding to each fertilizer barrel in the next fertilization cycle, and compensate for the uneven fertilization generated in the current fertilization cycle in the next fertilization cycle. When there is a long-term warning of uneven fertilizer application between fertilizer paths, the compensation data corresponding to the fertilizer that needs to be compensated is calculated based on the difference in fertilizer application amount, and a compensation plan for the subsequent fertilization plan is obtained. When the compensation data is large, compensation can be implemented in multiple subsequent fertilization cycles, and the target fertilizer application amount of the fertilizer barrel corresponding to the fertilizer in these cycles is adjusted so that the total compensation in all compensation cycles is consistent with the compensation data. In addition, for the Hall flowmeter corresponding to the fertilizer barrel with inaccurate fertilization for a long time, the main control board can give maintenance suggestions.

[0108] Preferably, as fertilization and irrigation proceed, when the amount of fertilizer liquid stored in the fertilizer bucket is low, it is necessary to add fertilizer to the fertilizer bucket, which will cause the initial liquid level of the fertilizer bucket to change. Therefore, a new round of flow correction and fault warning function detection is required after the fertilizer adding operation is completed. Based on this, the method further includes the following steps S501-S502:

[0109] After the fertilizer adding operation for the fertilizer barrel is completed, the preset time is extended and the step of collecting the liquid level data using the liquid level sensor is implemented, that is, the above steps S202 to S204 are implemented to obtain the latest liquid level data as the initial liquid level data for subsequent calculations.

[0110] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for flow correction and fault warning of a water-fertilizer integrated machine, the method comprising: Obtain the flow data collected by the Hall flow meter and calculate the amount of fertilizer based on it; Acquire liquid level data collected by the liquid level sensor; It is characterized in that the liquid level sensor performs data collection when the water-fertilizer integrated machine is stopped and not in operation, and the method further comprises: Calculating the actual fertilization volume according to the liquid level data collected by the liquid level sensor, and correcting the flow pulse parameter of the Hall flowmeter based on the actual fertilization volume; Compare and analyze the actual fertilizer volume of a single fertilizer bucket with the theoretical fertilizer volume corresponding to the fertilizer bucket to determine whether the difference between the two exceeds the set threshold. If so, a low fertilization accuracy fault warning is given; Compare the actual fertilizer volumes of various fertilizer barrels to determine whether the application ratios of the various fertilizers are balanced. Otherwise, give an early warning of unbalanced application.

2. The method for flow correction and fault warning of a water-fertilizer integrated machine according to claim 1 is characterized in that: The step of obtaining the liquid level data collected by the liquid level sensor comprises: Determine whether the preset key sampling time node has been reached, and if so, continue to execute subsequent steps; The liquid level sensor is used to collect real-time liquid level data at fixed time intervals, and the real-time liquid level data collected multiple times are cached into an array; The array is verified by a first-level data straight line smoothness filtering algorithm to obtain a valid array that meets preset requirements; The effective array is processed by a second median average filtering algorithm to obtain the liquid level data.

3. The method for flow correction and fault warning of a water-fertilizer integrated machine according to claim 2 is characterized in that: The array is verified by the first data straight line smoothness filtering algorithm to obtain a valid array that meets the preset requirements, including: Adjacent data difference processing is performed on the values ​​in the array, and statistical analysis is performed to determine whether each difference calculated is less than a set threshold. If so, the cached array is considered valid and is used as the valid array.

4. The method for flow correction and fault warning of a water-fertilizer integrated machine according to claim 2 is characterized in that: The performing a second median average filtering algorithm process on the effective array to obtain the liquid level data specifically includes: Sorting the data in the valid array in ascending order; According to the preset filter window size, the middle part of the sorted data is intercepted; The data in the filtering window is averaged, and the average processing is performed based on the following formula: y=average(x [(m-k) / 2] ,…,x [(m+k) / 2-1] ); Among them, y is the output result of the filtering algorithm; m is an even number, representing the total number of sampling points; k is an even number, representing the size of the filtering window; x [(m-k) / 2] ,…,x [(m+k) / 2-1] The window sampling values ​​are selected after the original array is sorted from small to large.

5. The method for flow correction and fault warning of a water-fertilizer integrated machine according to claim 1 is characterized in that: The liquid level sensor is a non-contact millimeter wave radar liquid level sensor, which is installed at the middle position of the top of the fertilizer barrel, and the liquid level data is the distance value between the probe of the non-contact millimeter wave radar liquid level sensor and the liquid surface; the actual fertilization volume is calculated according to the liquid level data collected by the liquid level sensor, and the flow pulse parameter of the Hall flowmeter is corrected based on the actual fertilization volume, including: The fertilizer amount is calculated based on the first reflection height h1 measured at the previous key sampling time node and the second reflection height h2 measured at the current key sampling time node. The calculation formula is as follows: V=S*△h=π*r 2 *(h2-h1); Among them, V is the amount of fertilizer applied during the fertilization cycle between two key sampling time nodes, in L; S is the cross-sectional area of ​​the cylindrical fertilizer barrel, in mm 2 ; △h is the change in liquid level in the fertilizer bucket before and after fertilization in one day, unit is mm; r is the radius of the fertilizer bucket, unit is mm; The flow pulse parameters are calculated based on the following formula: Q = N / V; Among them, N is the total number of pulses output by the Hall flowmeter during the fertilization process, and Q is the calibrated flow pulse parameter value of the flowmeter.

6. The method for flow correction and fault warning of a water-fertilizer integrated machine according to claim 1 is characterized in that: The actual fertilizer volumes of the various fertilizer barrels are compared to determine whether the application ratios of the various fertilizers are balanced. Otherwise, an early warning of imbalanced application is given, including: Compare the actual fertilizer volumes of all fertilizer buckets after a single fertilization cycle is completed, and determine whether the converted difference between the actual fertilizer volumes corresponding to the fertilizer buckets exceeds a preset threshold. If so, give a short-term warning of uneven fertilizer application between fertilizer routes; The actual total volume of fertilizer applied by all fertilizer buckets after multiple fertilization cycles is compared to determine whether the converted difference between the actual total volume of fertilizer applied by each fertilizer bucket exceeds a preset threshold. If so, a warning of long-term imbalance in fertilizer application between routes is given.

7. The method for flow correction and fault warning of a water-fertilizer integrated machine according to claim 1 is characterized in that: The method further comprises: After the fertilizer adding operation for the fertilizer barrel is completed, the preset time is extended, and the step of collecting the liquid level data using the liquid level sensor is implemented to obtain the latest liquid level data as the initial liquid level data for subsequent calculations.

8. A system for flow correction and fault warning of a water-fertilizer integrated machine, characterized in that: The system comprises: Multiple fertilizer buckets; A fertilizer liquid pipeline, a flow regulating valve, a Hall flow meter and a liquid level sensor are arranged corresponding to each of the fertilizer barrels; A main control board, all the flow regulating valves, the Hall flowmeter and the liquid level sensor are connected to the main control board, and the main control board can implement the method for flow correction and fault warning of the water-fertilizer integrated machine according to any one of claims 1 to 7; The power module is used to supply power to each power consumption unit.

9. The system for flow correction and fault warning of the integrated water and fertilizer machine according to claim 8 is characterized in that: The Hall flowmeter outputs a pulse signal, which is modulated by the optical coupling isolation input circuit of the main control board and then input to the MCU main control unit of the main control board.

10. The system for flow correction and fault warning of the integrated water and fertilizer machine according to claim 8, characterized in that: The main control board is connected with a touch screen.

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