Flow rate grading regulation based omnidirectional water-saving irrigation method and system for farmland

Abstract

This invention discloses a method and system for omnidirectional water-saving irrigation of farmland based on flow-level regulation, belonging to the field of water-saving irrigation technology. The method and system include: S1, collecting real-time data of omnidirectional irrigation operation, obtaining historical switching event identifier sequences, and preprocessing them; S2, executing step-by-step gradual control of variable frequency pump output frequency ramp constraints and valve opening feedback values ​​based on the overshoot discrimination results of the switching event windows, and generating a switching event window evidence package; S3, outputting the corrected total water consumption and triggering metering verification based on the integral correction analysis and corrected water consumption consistency analysis results; S4, performing evidence supplementation and switching suppression closed-loop regulation, and completing the archiving and issuance of water-saving metering conclusions. This solves the problem of existing graded irrigation systems estimating water consumption based on steady-state timing and nominal flow rate, ignoring the accumulation of flow overshoot within the switching event window, leading to systematic bias in water-saving assessments and a lack of traceable evidence chains.

Claims

1. A method for omnidirectional water-saving irrigation of farmland based on flow-level regulation, characterized in that, Includes the following steps: S1: Collect real-time data of omnidirectional irrigation operation and obtain historical data switching event identifier sequences; preprocess the real-time data of omnidirectional irrigation operation. S2, perform overshoot judgment on the real-time data of omnidirectional irrigation operation and the historical switching event identifier sequence, and perform step-by-step gradual control of variable frequency pump output frequency ramp constraint and valve opening feedback value based on the overshoot judgment result of the switching event window, and generate a switching event window evidence package. S3 performs integral correction analysis and corrected water use consistency analysis on the real-time data of omnidirectional irrigation operation and the evidence package of the cut-off event window. Based on the results of the integral correction analysis and corrected water use consistency analysis, it outputs the corrected total water use, the corrected water-saving assessment mark, and triggers metering verification. S4. Perform a quantitative analysis of the completeness of evidence for the event window evidence package and the revised total water consumption. Based on the results of the quantitative analysis of the completeness of evidence, perform evidence supplementation and closed-loop regulation to suppress the event window, and complete the archiving and issuance of the water-saving metering conclusion.

2. The method for omnidirectional water-saving irrigation of farmland based on flow graded regulation according to claim 1, characterized in that: The specific process for collecting real-time data on omnidirectional irrigation operation and obtaining historical data switching event identifier sequences is as follows: Collect real-time data on omnidirectional irrigation operation, including: instantaneous volumetric flow rate of the main pipe, instantaneous volumetric flow rate of the omnidirectional coverage branches, pressure value of the main pipe, pressure value of the omnidirectional coverage branches, output frequency of the variable frequency pump, output current of the variable frequency pump, valve opening feedback value, valve action time, time of issuance of flow grading level command, time of confirmation of flow grading level receipt, omnidirectional irrigation start / stop status markers and unified timestamp sequence; obtain historical switching event identifier sequence.

3. The method for omnidirectional water-saving irrigation of farmland based on flow graded regulation according to claim 1, characterized in that: The specific process for preprocessing the real-time data of omnidirectional irrigation operation is as follows: Outlier removal and noise smoothing are performed on the instantaneous volumetric flow rate of the main pipe, the instantaneous volumetric flow rate of the omnidirectional coverage branches, the pressure value of the main pipe, and the pressure value of the omnidirectional coverage branches. A time sequence integrity check is performed on the unified timestamp sequence using a timestamp monotonicity check and adjacent sampling interval consistency detection algorithm, and missing measurement segment markers are output. Missing sequences are filled in for the variable frequency pump output frequency, variable frequency pump output current, and valve opening feedback value using a piecewise linear interpolation and missing measurement segment upper bound constraint completion algorithm. The real-time data of omnidirectional irrigation operation are standardized using a zero-mean unit variance standardization algorithm. The real-time data of omnidirectional irrigation operation is normalized using a linear normalization algorithm.

4. The method for omnidirectional water-saving irrigation of farmland based on flow graded regulation according to claim 1, characterized in that: The specific process for determining overshoot of the event window in the real-time data of omnidirectional irrigation operation and the historical event switching identifier sequence is as follows: The timing of the flow classification level instruction and the instantaneous volume flow of the main pipe are used to construct the timing event window and lock the boundary of the timing event window. The instantaneous volume flow of the main pipe within the timing event window is first estimated by the middle value of the sliding window length before the starting point of the timing event window. The overshoot volume is calculated by the timing event window differential integral algorithm on the event baseline flow. The delay time of the instruction receipt is calculated by the difference between the confirmation time of the traffic tier acknowledgment and the issuance time of the traffic tier instruction. The pressure fluctuation intensity of the main pipe is calculated by the difference between the maximum and minimum values ​​within the switching event window; the consistency of valve action is determined by a time consistency discrimination algorithm between the valve action completion time and the flow classification level confirmation time. Calculate the ratio of the overshoot volume to the sum of the overshoot volumes, take the negative sign of the ratio and calculate the exponential function value, then subtract the exponential function value from the sum to obtain the exponential mapping term of the overshoot volume. Calculate the hysteresis time of the instruction acknowledgment and take its natural logarithm to obtain the logarithmic term of the instruction acknowledgment hysteresis; calculate the hyperbolic tangent of the pressure fluctuation intensity during gear shifting to obtain the hyperbolic tangent term of the pressure fluctuation. Calculate the negative value of the consistency of valve action and calculate the exponential function value to obtain the consistency logic denominator term; The pressure consistency ratio term is obtained by calculating the ratio of the hyperbolic tangent term of pressure fluctuation to the denominator term of consistency logic. The overshoot discrimination value of the shift event window is obtained by multiplying the overshoot volume index mapping term, the instruction acknowledgment hysteresis logarithm term, and the pressure consistency ratio term.

5. The method for omnidirectional water-saving irrigation of farmland based on flow graded regulation according to claim 1, characterized in that: The specific process of performing step-by-step gradual control of the variable frequency pump output frequency ramp constraint and valve opening feedback value based on the overshoot judgment result of the cut-off event window and generating the cut-off event window evidence package is as follows: Real-time comparison of the overshoot detection value and the overshoot detection threshold of the file switching event window: When the overshoot discrimination value of the cut-off event window is less than the overshoot discrimination threshold of the cut-off event window, the start point and end point of the cut-off event window are output, and it is determined that the cut-off event window has the overshoot measurable condition, and then the integral correction analysis and correction water use consistency analysis are entered. When the overshoot judgment value of the switching event window is greater than or equal to the overshoot judgment threshold of the switching event window, the switching ramp constraint flag and the switching trigger interval constraint flag are output. Frequency ramp constraint and frequency drop constraint are applied to the output frequency of the variable frequency pump: the change in the output frequency of the variable frequency pump within adjacent control cycles does not exceed the maximum change rate per unit time calculated according to the control cycle. The valve opening feedback value is adjusted to the target opening value in each control cycle according to the opening step size, and ends when the absolute value of the difference between the valve opening feedback value and the target opening value is not greater than the opening resolution. The starting point of the switching event window, the ending point of the switching event window, the overshoot volume, the switching pressure fluctuation intensity, the instruction acknowledgment delay time, the time of issuance of the flow classification gear instruction, and the time of confirmation of the flow classification gear acknowledgment are written into the switching event window evidence package. Proceed to integral correction analysis and correction water usage consistency analysis.

6. The method for omnidirectional water-saving irrigation of farmland based on flow graded regulation according to claim 1, characterized in that: The specific process of performing integral correction analysis and corrected water use consistency analysis on the real-time data of omnidirectional irrigation operation and the evidence package of the cut-off event window is as follows: The start and end times of the operating period are determined by the time when the omnidirectional irrigation start and stop status markers switch from non-operating to operating and from operating to non-operating in the unified timestamp sequence. The steady-state water consumption is obtained by integrating the instantaneous volumetric flow rate of the main pipe within the operating period. The corrected total water consumption is obtained by adding the cumulative overflow volumetric flow rate. The total water consumption of the branch is obtained by integrating and summing the instantaneous volumetric flow rate of the omnidirectional coverage branch over the operating time period; The sampling missing intensity is calculated by statistically analyzing the proportion of missing segments in a unified timestamp sequence; The time alignment residual strength is obtained by using an alignment residual calculation algorithm to calculate the time alignment residual strength at the time of issuing the flow grade level command, the time of valve action, and the time of overshoot peak. Calculate the difference between the corrected total water consumption and the branch water consumption and take the absolute value to obtain the water consumption difference range; calculate the ratio of the water consumption difference range to the water consumption difference range plus the water consumption difference range plus the absolute value and then calculate the exponential function value; subtract the exponential function value from the absolute value to obtain the water consumption difference exponential mapping term. Calculate the reciprocal of the sampling omission intensity to obtain the sampling omission reciprocal adjustment term; Calculate the reciprocal of the time alignment residual strength to obtain the time alignment residual reciprocal adjustment term; The corrected water usage consistency discrimination value is obtained by multiplying the water usage difference index mapping term, the sampling missing measurement reciprocal adjustment term, and the time alignment residual reciprocal adjustment term.

7. The method for omnidirectional water-saving irrigation of farmland based on flow graded regulation according to claim 1, characterized in that: The specific process of outputting the corrected total water consumption and corrected water conservation assessment marker, and triggering metering verification based on the results of integral correction analysis and corrected water use consistency analysis is as follows: Real-time comparison and correction of water usage consistency criteria and water consumption consistency threshold: When the corrected water usage consistency judgment value is less than the corrected water consumption consistency judgment threshold, a metering verification trigger flag is output to increase the sampling point density of the main pipe instantaneous volume flow rate and the omnidirectional coverage branch instantaneous volume flow rate; Improve the granularity of recording the confirmation time of flow classification level and the valve action time, and create and write the sampling missing measurement intensity and time alignment residual intensity into the abnormal measurement database; Proceed to the quantitative analysis of evidence completeness; When the corrected water use consistency discrimination value is greater than or equal to the corrected water use consistency discrimination threshold, the corrected total water use and the corrected water-saving assessment flag are output, and the process proceeds to the evidence completeness quantitative analysis.

8. The method for omnidirectional water-saving irrigation of farmland based on flow graded regulation according to claim 1, characterized in that: The specific process for conducting a quantitative analysis of the completeness of evidence for the event window evidence package and the corrected total water consumption is as follows: The field completeness rate of the evidence package is calculated by the ratio of the number of required fields present to the total number of required fields in the event window; the time continuous coverage rate is calculated by the coverage rate statistics of the instantaneous volume flow rate sampling points of the main pipe in the event window. The conserved residual value is obtained by calculating the difference between the corrected total water consumption and the total water consumption of the branch roads; Calculate the field completeness rate of the evidence package and take its natural logarithm to obtain the logarithmic term of the field completeness rate of the evidence package; Calculate the time continuous coverage rate and take its natural logarithm to obtain the logarithmic term of the time continuous coverage rate; calculate the absolute value of the conserved residual value, add it to the logarithmic term of the conserved residual and take its natural logarithm to obtain the logarithmic suppression term of the conserved residual; calculate the sum of the logarithmic term of the evidence package field integrity rate and the logarithmic term of the time continuous coverage rate, and then subtract the logarithmic suppression term of the conserved residual to obtain the logarithmic synthesis term of the evidence completeness; calculate the logistic function value of the logarithmic synthesis term of the evidence completeness to obtain the evidence completeness value of water-saving metering.

9. The method for omnidirectional water-saving irrigation of farmland based on flow graded regulation according to claim 1, characterized in that: The specific process of performing evidence supplementation and filing suppression closed-loop adjustment based on the quantitative analysis results of evidence completeness, and completing the archiving and issuance of water-saving metering conclusions is as follows: Real-time comparison of the completeness value of water-saving metering evidence and the threshold for completeness of water-saving metering evidence: When the water-saving metering evidence completeness value is less than the water-saving metering evidence completeness threshold, evidence completion and segmentation suppression are initiated: record the valve action time and increase the sampling point density of valve opening feedback value, while increasing the sampling point density of variable frequency pump output frequency and variable frequency pump output current; enable segmentation trigger interval constraint flag and expand the balance judgment window length; create and archive the field gap type, sampling missing measurement intensity and time alignment residual intensity to the evidence defect database; When the water-saving metering evidence completeness value is greater than or equal to the water-saving metering evidence completeness threshold, the corrected total water consumption, over-flushing volume, corrected water consumption consistency judgment value, and over-flushing judgment value of the cut-off event window will be created and archived to the water-saving metering database.

10. A farmland omnidirectional water-saving irrigation system based on flow-level regulation, employing the farmland omnidirectional water-saving irrigation method based on flow-level regulation as described in any one of claims 1-9, comprising: The data acquisition and preprocessing module is used to acquire real-time data of omnidirectional irrigation operation and obtain historical data cutoff event identifier sequences; Preprocess the real-time data of omnidirectional irrigation operation; The overshoot detection module for the cut-off event window is used to detect the overshoot of the cut-off event window on the real-time data of the omnidirectional irrigation operation and the historical cut-off event identifier sequence. Based on the overshoot detection result of the cut-off event window, it performs step-by-step gradual control of the variable frequency pump output frequency ramp constraint and valve opening feedback value and generates the cut-off event window evidence package. The water consumption consistency judgment module is used to perform integral correction analysis and correct water consumption consistency analysis on the real-time data of omnidirectional irrigation operation and the evidence package of the file-cutting event window. Based on the results of the integral correction analysis and correct water consumption consistency analysis, it outputs the corrected total water consumption and the corrected water-saving assessment mark, and triggers the metering verification. The evidence chain archiving and file-cutting suppression closed-loop adjustment module is used to perform quantitative analysis of the completeness of evidence packages and corrected total water consumption in the file-cutting event window. Based on the results of the quantitative analysis of evidence completeness, it performs evidence supplementation and file-cutting suppression closed-loop adjustment and completes the archiving and issuance of water-saving metering conclusions.

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