Portable automatic water injection system for verifying rain gauge

Abstract

The portable automatic water injection system comprises a microcomputer, a peristaltic pump, a data acquisition module and a printer, a data processing algorithm is built in the microcomputer, and the microcomputer is used for setting water injection parameters, controlling operation of the peristaltic pump, receiving and processing feedback signals of the data acquisition module and calculating indication errors and deviation values; the data acquisition module and the printer are connected to the microcomputer through cables, the microcomputer is connected to the lithium battery, and the data acquisition module is a 485AD conversion module / pulse collector and is used for receiving digital signals or pulse signals of a to-be-tested rain gauge and feeding back data to the microcomputer; according to the invention, through automatic water injection and intelligent data processing, the efficiency and precision of pluviometer verification are significantly improved. The portable design is suitable for field operation, and a verification report can be quickly generated. The system supports various rain intensity simulation and signal input modes, is high in adaptability, and provides reliable technical support for hydrological and meteorological monitoring.

Description

Technical Field

[0001] The invention relates to the technical field of hydrology and meteorology, in particular to a portable automatic water filling system for calibrating a rain gauge. Background Art

[0002] Precipitation is a key component of the hydrological and meteorological cycles and a crucial element in hydrological and meteorological monitoring. Rainfall provides crucial support and foundation for flood control, drought relief, and water resources management. Therefore, the accuracy of rain gauge data must be regularly verified to prevent significant data deviations.

[0003] At present, most hydrological stations and meteorological stations in China use manual rain gauges to conduct regular calibration of tipping bucket rain gauges and weighing rain gauges. When the human visual identification of the water level scale line or the measuring cup is inaccurate, certain errors will inevitably occur. This device uses a peristaltic pump for quantitative water injection. An algorithm is added to the program to ensure that different volumes of rain are injected under the same rainfall intensity. The accuracy of the rain gauge used on site is calibrated, and the parameters of the rain gauge can be adjusted on site according to the calibration values, so that the accuracy of the data is effectively guaranteed. The instrument operation saves time and labor, and the device structure is simple. While improving efficiency, it reduces costs and improves accuracy. The instrument is easy to operate and the measurement results are accurate and reliable, providing strong data support for the collection and analysis of basin hydrological, meteorological, and agricultural information. Summary of the Invention

[0004] In view of this, in order to solve the problems existing in the technical background, the present invention proposes a portable automatic water filling system for calibrating rain gauges. Specifically, it includes the following contents:

[0005] A portable automatic water filling system for calibrating a rain gauge includes a microcomputer, a peristaltic pump, a data acquisition module, and a printer. The microcomputer has a built-in data processing algorithm for setting water filling parameters, controlling the operation of the peristaltic pump, receiving and processing feedback signals from the data acquisition module, and calculating indication error and deviation values.

[0006] The peristaltic pump is connected to the water container and the rain gauge to be measured through a hose, and is controlled by a microcomputer to achieve quantitative water injection.

[0007] The data acquisition module and the printer are both connected to a microcomputer via a cable, and the microcomputer is connected to a lithium battery. The data acquisition module is a 485AD conversion module / pulse collector for receiving digital signals or pulse signals from the rain gauge to be measured and feeding the data back to the microcomputer;

[0008] The printer is electrically connected to the microcomputer and is used to output a calibration report, including water injection parameters, rain gauge feedback values, indication errors and deviation values;

[0009] The data acquisition module is connected to the rain gauge to be measured, collects the display data fed back from the rain gauge to be measured and sends the result to the microcomputer, which calculates the data returned by the rain gauge to be measured and calculates the indication error and deviation value.

[0010] Furthermore, the microcomputer uses limiting filtering, median filtering and moving average filtering algorithms to process data, effectively reducing noise interference.

[0011] Furthermore, the peristaltic pump water injection rate can be adjusted in the range of 0.5 to 10 mm / min, and the step accuracy is 0.1 mm / min.

[0012] Furthermore, the peristaltic pump connects the pump tube outlet to a glass rain gauge, inputs the target rainfall intensity and rainfall value, starts the calibration program, records the deviation between the actual water injection volume and the target value, and the microcomputer automatically adjusts the pump speed and repeats the water injection until the error is less than ±0.1mm.

[0013] The above technical solution has the following beneficial effects:

[0014] This invention significantly improves the efficiency and accuracy of rain gauge calibration through automated water injection and intelligent data processing. Its portable design is suitable for field operations, offers ease of operation, and rapidly generates calibration reports. The system supports a variety of rainfall intensity simulation and signal input methods, offering strong adaptability and providing reliable technical support for hydrological and meteorological monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a structural schematic diagram of a portable automatic water filling system for calibrating a rain gauge. DETAILED DESCRIPTION

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] See also Figure 1 A portable automatic water filling system for calibrating a rain gauge is shown, comprising a microcomputer, a peristaltic pump, a data acquisition module, and a printer. The microcomputer has a built-in data processing algorithm for setting water filling parameters, controlling the operation of the peristaltic pump, receiving and processing feedback signals from the data acquisition module, and calculating indication error and deviation values.

[0018] The peristaltic pump is connected to the water container and the rain gauge to be measured through a hose, and is controlled by a microcomputer to achieve quantitative water injection.

[0019] The data acquisition module and the printer are both connected to the microcomputer via cables. The microcomputer is connected to a lithium battery. The data acquisition module is a 485AD conversion module / pulse collector, which is used to receive the digital signal or pulse signal of the rain gauge to be measured and feedback the data to the microcomputer;

[0020] The printer is electrically connected to the microcomputer and is used to output a calibration report, including water injection parameters, rain gauge feedback values, indication errors, and deviation values;

[0021] The data acquisition module is connected to the rain gauge to be measured, collects the display data fed back from the rain gauge to be measured, and sends the result to the microcomputer. The microcomputer calculates the data returned by the rain gauge to be measured and calculates the indication error and deviation value.

[0022] In this embodiment, the microcomputer uses clipping filter, median filter and moving average filter algorithms to process data, effectively reducing noise interference. The adjustable range of the water injection rate of the peristaltic pump is 0.5 - 10 mm / min, and the step accuracy is 0.1 mm / min. The peristaltic pump connects the outlet of the pump tube to the glass rain gauge, inputs the target rain intensity and rain amount value, starts the calibration program, records the deviation between the actual water injection amount and the target value, and the microcomputer automatically adjusts the pump speed and repeats the water injection until the error is less than ±0.1 mm.

[0023] First, the clipping filter is used to set the upper and lower thresholds to limit the data outside the threshold range within the threshold range to reduce the influence of noise on the signal. It is applicable to the processing of unconventional noise and outliers. Then, the median filter is used to suppress noise by calculating the median of the first 11 groups of data after moving average filtering. It has a good suppression effect on salt and pepper noise and pulse noise and has a good effect on sensor data processing. Finally, the moving average filter is used to smooth the signal by calculating the average value of data within a certain period (6s), effectively reducing the influence of high-frequency noise and is used for signal smoothing and denoising processing.

[0024] Principle of clipping filter: Set the threshold range, truncate the extreme values outside the range to the threshold boundary values to prevent accidental large values from interfering. Formula: If x(n) < min_thresh, y(n) = min_thresh; if min_thresh ≤ x(n) ≤ max_thresh, y(n) = x(n); if x(n) > max_thresh, y(n) = max_thresh

[0025] min_thresh: Lower threshold. max_thresh: Upper threshold. Thresholds are usually set based on experience or historical data (e.g., ±Δ is the allowable fluctuation range).

[0026] Median Filter, principle: replace the current value with the median of the data in the window to prevent impulse noise.

[0027] formula:

[0028] Take the sliding window [x(nk),…,x(n),…,x(n+k)] containing the current value, a total of 2k+1 points (k is the window radius).

[0029] Sort the data in the window: x(1)≤x(2)≤…≤x(2k+1).

[0030] Output median: y(n)=x(k+1).

[0031] The window size is usually an odd number (such as 3, 5, 7, etc.) to ensure that there is a unique middle value.

[0032] Moving Average Filter, principle: perform arithmetic averaging on N consecutive sampling values ​​to prevent periodic interference. Formula: x(n): The current n-th sampling value. y(n): The output value after the n-th filtering. N: The window size (the number of sampling points involved in the average). Variant weighted moving average: Different weights are assigned to the data within the window, such as the nearest value has a higher weight. The formula is as follows:

[0033]

[0034] During the specific implementation, the rain gauge to be tested is first connected to the signal input interface of the portable rain gauge titration system to receive the real-time feedback of the rainfall value.

[0035] The next step is to preheat the peristaltic pump, place the peristaltic pump inlet hose into the prepared water container, and add clean water for testing into the container. Place the peristaltic pump outlet into the matching glass rain gauge, and enter the rainfall intensity and rainfall value you want to calibrate on the microcomputer. Turn on the peristaltic pump, fill the entire pipeline with clean water, and after water flows out of the pump tube outlet, open the calibration screen and start the calibration program. The peristaltic pump draws clean water from the test container and injects it into the glass rain gauge through the peristaltic pump. After stopping at the set time, enter the actual value read on the glass rain gauge into the corresponding window, and click the calibration button to adjust the number of revolutions. The computer automatically calculates the new number of revolutions of the peristaltic pump. Click the start button again. After the end, observe whether the value in the glass rain gauge is consistent with the value entered on the microcomputer. If they are consistent, the calibration ends. If they are inconsistent, continue to calibrate the peristaltic pump repeatedly.

[0036] The next step is to calibrate the rain gauge. Connect the peristaltic pump outlet to the water inlet of the rain gauge to be tested, and connect the rain gauge signal line to the signal acquisition module of the portable automatic water filling system. At this point, you can choose digital output (the data volume is more accurate, the general resolution is 0.01mm, and the communication protocol needs to be provided in advance) or connect the pulse signal of the rain gauge to be tested (the general resolution is 0.1). At this time, the measurement program starts according to the rainfall intensity and rainfall values ​​set during calibration. After the program is completed, the rainfall value error of the titration value measured by the rain gauge to be tested can be obtained. The user can determine whether the rain gauge to be tested can continue to be used based on the error value given by the titrator or adjust the rain gauge parameters on site and titrate again. According to hydrological and meteorological definitions, precipitation can be divided into four rainfall intensities: 10mm / min heavy rainfall intensity, 4mm / min heavy rainfall intensity, 2mm / min medium rainfall intensity, and 1mm / min medium and small rainfall intensity. The rainfall intensity tested by this instrument can be divided into twenty levels to choose from: 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, and 10 mm / min. According to the "Precipitation Observation Specification" (SL21-2015), the default value is 2.0 mm / min.

[0037] The above describes the basic principles and main features of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the invention to be protected. The scope of protection of the invention is defined by the attached claims and their equivalents.

Claims

1. A portable automatic water filling system for calibrating a rain gauge, characterized in that: It includes a microcomputer, a peristaltic pump, a data acquisition module, and a printer. The microcomputer has a built-in data processing algorithm for setting water injection parameters, controlling the operation of the peristaltic pump, receiving and processing feedback signals from the data acquisition module, and calculating indication errors and deviations. The peristaltic pump is connected to the water container and the rain gauge to be measured through a hose, and is controlled by a microcomputer to achieve quantitative water injection. The data acquisition module and the printer are both connected to a microcomputer via a cable, and the microcomputer is connected to a lithium battery. The data acquisition module is a 485AD conversion module / pulse collector for receiving digital signals or pulse signals from the rain gauge to be measured and feeding the data back to the microcomputer; The printer is electrically connected to the microcomputer and is used to output a calibration report, including water injection parameters, rain gauge feedback values, indication errors and deviation values; The data acquisition module is connected to the rain gauge to be measured, collects the display data fed back from the rain gauge to be measured and sends the result to the microcomputer, which calculates the data returned by the rain gauge to be measured and calculates the indication error and deviation value.

2. A portable automatic water filling system for calibrating a rain gauge according to claim 1, characterized in that: The microcomputer uses limiting filtering, median filtering and moving average filtering algorithms to process data, effectively reducing noise interference.

3. A portable automatic water filling system for calibrating a rain gauge according to claim 1, characterized in that: The peristaltic pump water injection rate can be adjusted in the range of 0.5 to 10 mm / min, and the step accuracy is 0.1 mm / min.

4. A portable automatic water filling system for calibrating a rain gauge according to claim 1, characterized in that: The peristaltic pump connects the pump tube outlet to the glass rain gauge, inputs the target rainfall intensity and rainfall value, starts the calibration program, records the deviation between the actual water injection volume and the target value, and the microcomputer automatically adjusts the pump speed. Repeat the water injection until the error is less than ±0.1mm.

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