Intelligent hydrological monitoring system based on internet of things

Abstract

The application relates to the technical field of hydrological monitoring and discloses an intelligent hydrological monitoring system based on Internet of Things, which comprises an upper computer, a flow measurement control platform, a network communication module, a PLC controller, a mechanical system and a flow measurement system. The flow measurement control platform respectively instructs the PLC controller and the flow measurement system through the network communication module. The flow measurement system is used for acquiring hydrological monitoring data and uploading the flow measurement control platform. The flow measurement system comprises an ADCP flow measurement, a radar flow measurement, a time-difference method ultrasonic flow measurement, a propeller current meter and a field water level meter. The flow measurement system selects a flow measurement method according to needs at different measuring point positions in the same section to jointly measure the flow. The flow measurement system is equipped with multiple flow measurement methods and is uniformly controlled and dispatched by the flow measurement control platform, so that the monitoring system has good expandability. On this basis, a corresponding flow measurement scheme can be automatically generated according to different water level levels, the advantages and disadvantages of various flow measurement methods are complementary, and the detection precision is further improved.

Description

Technical Field

[0001] This invention relates to the field of hydrological monitoring technology, specifically to an intelligent hydrological monitoring system based on the Internet of Things. Background Technology

[0002] Currently, water resource management in various river basins faces challenges such as insufficient accuracy in water allocation, inconsistent metering technical standards, and low level of intelligence in monitoring systems. The primary task is to improve the accuracy of water diversion metering. However, due to the complex river conditions within the basin, such as high sediment content, turbid water flow, channel silt, large amounts of sediment, constantly changing channel cross-sections, and the condition of water intakes, traditional metering methods are greatly affected, resulting in significant metering errors.

[0003] With the development of IoT and big data technologies, the demand for intelligent water resource scheduling and sustainable utilization has emerged. This requires building a comprehensive monitoring network, expanding coverage, establishing a real-time dynamic water quantity monitoring system, achieving comprehensive data collection and efficient transmission, promoting the informatization upgrade of the monitoring and metering system, and relying on big data analysis, cloud computing, and artificial intelligence technologies to study and utilize an intelligent water quantity monitoring platform to enhance the automatic data processing capabilities, reduce human intervention, and improve management efficiency.

[0004] This application aims to construct an intelligent hydrological monitoring platform and a high-precision hydrological monitoring system. Summary of the Invention

[0005] In view of the shortcomings of existing hydrological monitoring systems mentioned in the background art, the present invention provides an intelligent hydrological monitoring system based on the Internet of Things, which has the advantages of unattended automatic flow measurement, joint flow measurement by multiple flow measurement methods to improve measurement accuracy, and automatic generation of accurate and reliable data reports, thus solving the technical problems mentioned in the background art.

[0006] This invention provides the following technical solution: an intelligent hydrological monitoring system based on the Internet of Things, comprising a host computer, a flow measurement control platform, a network communication module, a PLC controller, a mechanical system, and a flow measurement system; the flow measurement control platform runs on the host computer, and the flow measurement control platform communicates with the PLC controller and the flow measurement system through the network communication module; the PLC controller is used to identify the instructions of the flow measurement control platform and control the actions of the mechanical system; the mechanical system is used to undertake the action requirements of the flow measurement system during flow measurement; and the flow measurement system is used to acquire hydrological monitoring data and upload it to the flow measurement control platform.

[0007] Preferably, the flow measurement system includes ADCP flow measurement, radar flow measurement, time-of-flight ultrasonic flow measurement, propeller current meter, and field water level gauge. The flow measurement system can select flow measurement methods at different measurement points within the same cross section for combined flow measurement as needed.

[0008] Here, the selection of each flow measurement method can be based on its advantages and disadvantages and the applicable hydrological conditions. For example, radar measurement is suitable for measuring surface velocity and is best suited for relatively clean and calm water surfaces; time-of-flight (TOF) measurement is suitable for measuring turbulent flows with high sediment content and large cross-sectional areas; ADCP measurement is suitable for measuring flows with high accuracy requirements, relatively high velocity, and low sediment content. For example, for laminar flows with small surface waves, low sediment content at depths of 1-5 meters, and high sediment content at depths of 5-10 meters, a combined detection system can be set up: radar measurement for the surface, ADCP measurement for depths of 1-5 meters, and TOF measurement for depths of 5-10 meters. This combined detection system leverages the advantages of each flow measurement method to further improve the accuracy of the final cross-sectional flow velocity, flow rate, and other hydrological data, based on the upper limit of the accuracy of each detection device.

[0009] Preferably, based on the hydrological data of the same measuring point within the same cross section obtained by the joint flow measurement, the deviation between different flow measurement methods is calculated, and the current hydrological conditions are given a reverse warning.

[0010] This deviation refers to the degree of deviation between flow measurement data obtained from different flow measurement methods at the same measuring point within the same cross-section and the data obtained from one flow measurement method compared to similar data from another flow measurement method. The warning result is based on factors related to the different flow measurement methods used at that measuring point. For example, as mentioned above, ADCP flow measurement is used at the 1-5 meter measuring point, and time-of-flight flow measurement is used at the 5-10 meter measuring point. The factor is the difference in sediment content in the laminar flow at the 1-5 meter and 5-10 meter levels. In this case, if the deviation between the ADCP flow measurement result and the time-of-flight flow measurement result is small, it indicates a uniform sediment content in the entire laminar flow, and if the deviation is large, it indicates a significant difference in sediment content in the laminar flow, and the combined detection result is closer to the high-precision requirements. This can be further confirmed by combining monitoring video.

[0011] Preferably, the mechanical system includes a triangular bridge, an electric winch, a gantry crane, lifting equipment, and video acquisition. The triangular bridge is erected on both banks of the river / channel to be measured. The electric winch is fixedly installed on the triangular bridge, and the gantry crane is slidably installed on the triangular bridge. The electric winch drives the gantry crane to move back and forth across the river / channel at the bottom of the triangular bridge. The lifting equipment is fixedly installed on the triangular bridge and uses lifting guide wheels to carry the equipment for hydrological measurement for vertical lifting. The video acquisition is used to obtain real-time dynamics of the site environment.

[0012] Preferably, the flow measurement control platform consists of a flow measurement dynamic simulation module, a measurement setting module, a manual / automatic operation module, a video operation module, a video display module, and a status display module. The flow measurement dynamic simulation module is used to intuitively display a panoramic view and enlarged view of the river cross-section, and dynamically simulates the entire flow measurement process of the flow measurement cross-section during flow measurement. The measurement setting module is used to complete parameter setting, measurement setting, real-time preview, and printing measurement reports. The manual / automatic operation module is used to complete manual and automatic switching operations to control the operation of the flow measurement equipment. The video operation module is used to control the pan-tilt camera to rotate up, down, left, and right to obtain real-time dynamic images of the surrounding environment. The video display module is used to display the video images collected by the video operation module. The status display module is used to display the current operating status of each device in real time.

[0013] Preferably, the network communication module consists of an intranet and an extranet. Interconnection between devices within the flow measurement system uses the intranet, while data communication between the flow measurement system and the flow measurement control platform, and between the mechanical system and the flow measurement control platform, uses the extranet. Intranet data transmission is accomplished via microwave communication, while extranet data transmission is achieved via the Internet or a dedicated network.

[0014] Preferably, the main functions of the measurement setting module include flow measurement settings, parameter settings, real-time flow measurement preview, and printing of flow result tables.

[0015] Preferably, after the flow measurement settings are completed, the flow measurement control platform automatically reads the water level gauge data and generates the distance between the starting points of the left and right vertical lines, automatically generates the measurement method for the corresponding vertical lines, and can modify the automatically generated measurement method.

[0016] Preferably, the parameter settings include setting the water depth measurement range corresponding to the 1-5 point method on each vertical line.

[0017] Preferably, during the real-time flow measurement preview process, a real-time warning is issued for problematic measurement points, and retesting or supplementary testing is performed.

[0018] The present invention has the following beneficial effects: 1. The present invention has an automatic water level acquisition function. The flow measurement system can perform unattended automatic flow measurement according to the set time and the set water level change, and can automatically generate corresponding flow measurement schemes according to different water level levels.

[0019] 2. This invention integrates multiple flow measurement methods into a flow measurement system, which is then uniformly controlled and scheduled by a flow measurement control platform, giving the monitoring system excellent scalability. Based on this, it can automatically generate corresponding flow measurement schemes according to different water level levels, allowing the advantages and disadvantages of each flow measurement method to complement each other. This provides a solution to improve measurement accuracy at the flow measurement scheme level, further enhancing detection accuracy beyond the upper limit of the equipment accuracy used in existing flow measurement methods.

[0020] 3. After the flow measurement is completed, the system of this invention will automatically generate a data report that meets the requirements of hydrological specifications. The generated report data cannot be modified, which prevents human tampering with the original data and ensures the authenticity and reliability of the data measurement. Under the premise of meeting the requirements of flow measurement specifications, the system shortens the measurement time, reduces labor intensity, reduces human operation error and hardware failure rate, and improves the stability and reliability of the measurement.

[0021] 4. This invention establishes a data sharing mechanism by uploading unalterable data reports to a server, which can promote multi-departmental collaborative management, reduce information silos, and improve the transparency of water resource allocation. Attached Figure Description

[0022] Figure 1 This is a block diagram of the system structure of the present invention;

[0023] Figure 2 This is a schematic diagram of the mechanical system structure layout of the present invention;

[0024] Figure 3 This is a schematic diagram of the layout of the flow measurement and control platform modules of the present invention;

[0025] Figure 4 This is a schematic diagram of the measurement settings window of the present invention;

[0026] Figure 5 For the present invention Figure 4 A schematic diagram of the window for displaying measurement methods in China;

[0027] Figure 6 For the present invention Figure 4 A schematic diagram showing the window for adding and subtracting vertical lines after executing ADCP;

[0028] Figure 7 For the present invention Figure 4 A schematic diagram showing the adjustment of the measurement methods for each vertical line.

[0029] Figure 8 This is a schematic diagram of radar-based current meter measurement in the appendix of this invention;

[0030] Figure 9 This is a schematic diagram of the antenna illumination area of ​​the radar-based water level gauge and current meter in the appendix of this invention;

[0031] Figure 10 This is a schematic diagram of radar flow measurement in the appendix of this invention;

[0032] Figure 11 This is a schematic diagram of the instrument distribution of the time difference method system in the appendix of this invention;

[0033] Figure 12 For the present invention Figure 3 A partially enlarged schematic diagram of the dynamic simulation module for medium-speed flow measurement;

[0034] Figure 13 For the present invention Figure 3 A magnified view of a portion of the status display module.

[0035] In the diagram: 1. Triangular cable tray; 2. Electric winch; 3. Crane frame; 4. Lead weight; 5. Flow measurement control box; 100. Flow measurement dynamic simulation module; 200. Measurement setting module; 300. Manual / automatic operation module; 400. Video operation module; 500. Video display module; 600. Status display module. Detailed Implementation

[0036] Please see Figures 1-3 The IoT-based intelligent hydrological monitoring system includes a host computer, a flow control platform, a network communication module, a PLC controller, a mechanical system, and a flow measurement system.

[0037] The host computer is a computer or embedded server module that installs and runs executable programs. The flow measurement and control platform is mounted on the computer or embedded server module and can run. The embedded server can use the Linux operating system, which is stable and reliable.

[0038] The mechanical system and the flow measurement system are physical devices installed at the hydrological monitoring site.

[0039] The mechanical system includes a triangular cable frame 1, an electric winch 2, a traveling frame 3, lifting equipment, and video acquisition. The triangular cable frame 1 is a steel truss structure, consisting of two columns and a truss. The two columns are erected on the banks of the river / channel to be measured, fixed to the ground with reinforced concrete and bolts. The truss spans the river / channel and is erected at the top of the two columns. The electric winch 2 is fixedly installed on one of the columns of the triangular cable frame 1. The traveling frame 3 is slidably installed at the bottom end of the truss of the triangular cable frame 1. The electric winch 2 drives the traveling frame 3 to move horizontally back and forth at the bottom end of the truss of the triangular cable frame 1 via a transmission chain or steel cable. The lifting equipment is fixedly installed on the triangular cable frame 1. On one column of the angle bridge 1, the lifting equipment and the electric winch 2 are mounted on the same column. A lifting guide wheel is rotatably mounted at the bottom of the gantry frame 3. The steel cable of the lifting equipment passes around the lifting guide wheel and carries the equipment used for hydrological measurement. Video acquisition specifically involves cameras that capture the dynamics of the on-site environment. Multiple sets can be deployed, such as for tracking and monitoring external river channels and flow measurement equipment, monitoring the drive unit, and monitoring the river conditions ahead of the flow measurement. The external river monitoring camera is an infrared network high-definition intelligent PTZ camera, enabling omnidirectional manual monitoring of the river channel and automatic tracking of the flow measurement equipment's trajectory. The camera is a controllable pan-tilt unit, capable of vertical, horizontal, and vertical rotation control. The electric winch 2 drives the flow measurement equipment. A grating encoder is mounted on the winch drive shaft to achieve precise positioning of the gantry frame 3 / flow measurement equipment.

[0040] The flow measurement system includes ADCP flow measurement, radar flow measurement, time-difference ultrasonic flow measurement, propeller current meter, and field water level gauge.

[0041] ADCP flow measurement is a flow measurement method based on an acoustic Doppler current profiler; radar flow measurement is a flow measurement method based on a radar flow meter; time-of-flight ultrasonic flow measurement is a flow measurement method based on an acoustic full-section time-of-flight flow meter; propeller current meters are only used for velocity measurement and do not measure depth (i.e., they do not measure water depth); field level gauges are generally used to measure the current water level. For the specific measurement principles, advantages, and disadvantages of each flow measurement method, please refer to the appendices following this application.

[0042] The equipment used for ADCP flow measurement is mounted on one end of the steel cable of the lifting equipment and is raised and lowered in the water under the control of the lifting equipment. At the same time, it is moved horizontally within the span by the gantry frame 3. The equipment used for radar flow measurement is installed on the truss of the triangular bridge frame 1. The equipment used for time-of-flight ultrasonic flow measurement is installed on both sides of the river / channel cross-section where the triangular bridge frame 1 is located. The driving source for the lifting equipment and the electric winch 2 can be provided by two 1.5kw servo motors. The lead weight 4 for ADCP flow measurement weighs 50kg. When the gantry frame 3 moves horizontally, it is set to automatically stop when the starting distance is at its maximum and minimum. When the lifting equipment lifts the lead weight 4 vertically, it is set to automatically stop when the lead weight 4 is at its highest point and at the bottom of the river. The braking time of the lead weight 4 is less than 1s. Both horizontal and vertical movements are preset with automatic stop control based on the measurement point positioning.

[0043] In the vertical ADCP flow measurement, firstly, the electric winch 2 of the mechanical system drives the lead weight 4 to move above the flow measurement vertical line. Then, the lifting equipment drives the lead weight 4 below the water surface and sends the water surface signal to the flow measurement control platform. When the riverbed detection device detects that the lead weight 4 has descended to the riverbed, the lead weight 4 stops descending and sends the riverbed signal to the flow measurement control platform. The electric winch 2 lifts the lead weight 4 above the water surface, and finally lowers the lead weight 4 below the water surface again for flow measurement.

[0044] The flow measurement control platform uses a network communication module to control the PLC controller to control / drive the mechanical system to perform operations. The flow measurement control platform also uses the communication module to achieve command control and data exchange with the flow measurement system. The PLC controller is integrated into the flow measurement control box 5 and installed on the column of the triangular cable tray 1.

[0045] The flow measurement control platform consists of a flow measurement dynamic simulation module 100, a measurement setting module 200, a manual / automatic operation module 300, a video operation module 400, a video display module 500, and a status display module 600.

[0046] The flow measurement dynamic simulation module 100 is used to intuitively display panoramic and enlarged views of the river cross section. During flow measurement, it dynamically simulates the entire flow measurement process of the flow measurement cross section, including: real-time display of the position of the flow measurement equipment at the flow measurement cross section, real-time display of the position of each measuring point, the completion status of the measuring point and the flow velocity at the measuring point, real-time display of key data during the flow measurement process, and the ability to manually change the position of the slider (the display key simulated on the flow measurement dynamic simulation module 100 by the flow measurement equipment) to display the corresponding starting distance and water depth, etc.

[0047] The measurement settings module 200 is used to complete functions such as parameter setting, measurement settings, real-time preview, and printing measurement reports.

[0048] The manual / automatic operation module 300 is used to complete manual / automatic switching operations, inverter high / low speed switching operations, equipment outgoing / returning operations, and flow measurement device deployment / retraction operations. For automatic flow measurement, click the "Manual / Automatic" button to switch to automatic mode. Automatic flow measurement selects different flow measurement methods according to preset operating conditions.

[0049] The video operation module 400 is used to control the pan-tilt camera to rotate up, down, left, and right to obtain real-time dynamic images of the surrounding environment.

[0050] The video display module 500 is used to display the video images captured by the video operation module 400. Each camera occupies an independent screen, and each image can be scaled individually for easy observation of the flow measurement situation.

[0051] The status display module 600 is used to display the current operating status of each device in real time.

[0052] The network communication module is divided into an internal network and an external network. The internal network refers to a small local area network within the flow measurement system, while the external network refers to data communication between the flow measurement system, the mechanical system, and the flow control platform. Data transmission within the network is accomplished via microwave communication, while connections to external data are achieved through the Internet or a dedicated network. This enables remote operation, allowing for the remote setting and distribution of flow measurement plans, including parameters such as water level, starting point distance, velocity and depth measurement vertical lines, water depth, and single-line measurement time. In server mode, it not only enables remote flow measurement but also provides functions such as remote debugging, remote assistance, and automatic updates.

[0053] The flow measurement and control platform will be integrated into a host computer or embedded server module. First, the video operation module 400 and video display module 500 will be used to view the on-site environmental conditions. Then, the measurement parameters will be set using the measurement setting module 200. Next, the manual / automatic operation module 300 will switch between manual and automatic modes to control the electric winch 2, lifting equipment, and flow measurement system. The acquired parameters will be fed back to the flow measurement dynamic simulation module 100 for intuitive display. Water level acquisition has two functions: collecting data from on-site water level gauges and using water depth in flow calculations; and using the riverbed detection device on the lead weight 4 to measure actual water depth for flow calculations. After the actual water depth measurement is completed, the cross-sectional data can be updated. After comprehensive flow measurement is completed, the measurement setting module 200 will export the results of each parameter in the form of standardized reports. At this point, the intelligent hydrological monitoring platform and hydrological monitoring system are complete.

[0054] Because the flow measurement system incorporates multiple flow measurement methods and is uniformly controlled and scheduled by the flow measurement control platform, this monitoring system possesses excellent scalability. Furthermore, it can automatically generate corresponding flow measurement schemes based on different water level levels, allowing the advantages and disadvantages of each flow measurement method to complement each other. This provides a solution to improve measurement accuracy at the flow measurement scheme level, further enhancing detection accuracy beyond the upper limit of the equipment accuracy used in existing flow measurement methods.

[0055] This system features automatic water level acquisition, enabling unattended automatic flow measurement based on set time and water level changes. System reports are automatically generated and are accurate and reliable. After each flow measurement, the system automatically generates data reports in a format fully compliant with hydrological standards, allowing for direct compilation. Before report generation, any measurement point can be remeasured at any time if there are objections. Once generated, the data cannot be modified, preventing tampering and ensuring the authenticity and reliability of the measurements. While meeting flow measurement standards, this system shortens measurement time, reduces labor intensity, lowers the incidence of human error and hardware failure, and improves the stability and reliability of measurements, thus promoting reforms in measurement and reporting methods and the modernization of hydrology. By uploading unalterable data reports to the server to establish a data sharing mechanism, multi-departmental collaborative management can be promoted, information silos reduced, and the transparency of water resource allocation improved.

[0056] The following preferred embodiments supplement the functions that the above system needs to achieve when performing monitoring by combining the interface operation of the flow measurement and control platform.

[0057] The flow measurement and control platform is opened by running the computer; the interface is as follows: Figure 3 As shown, there are a total of six areas.

[0058] The flow measurement dynamic simulation module 100: intuitively displays a panoramic view of the river cross-section and a magnified view of the cross-section (double-click the panoramic view of the cross-section simulation). During flow measurement, it can dynamically simulate the entire process of cross-section flow measurement, including: real-time display of the position of the lead weight 4 at the flow measurement cross-section, real-time display of the position of each measuring point, the completion status of the measuring point and the main data such as the flow velocity at the measuring point, and the ability to view the corresponding starting point distance and water depth by sliding the mouse to the corresponding vertical line position.

[0059] Video operation module 400 and video display module 500: This embodiment is equipped with three cameras, installed in the following locations and for the following functions: two infrared network high-definition intelligent PTZ cameras are installed outside the cableway house, enabling all-around monitoring of the external river channel and the river conditions ahead of the flow measurement; one bullet camera is installed inside the gondola to track and monitor the lead weight 4 and the propeller current meter. The three video monitoring windows are embedded in the flow measurement software interface, and the video monitoring windows can be switched between each other and zoomed in / out.

[0060] Manual / Automatic Operation Module 300: Primarily handles manual / automatic switching, inverter high / low speed switching, crane head movement (departure and return), and the raising and lowering of the lead weight 4 and flow meter. Click the "Manual / Automatic" button to switch to manual or automatic mode as needed. For automatic flow measurement, click the "Manual / Automatic" button to switch to automatic mode. Clicking the "One-Key Return" button allows you to avoid floating objects or return to the initial position in an emergency.

[0061] Measurement settings module 200: Its main functions include flow measurement settings, parameter settings, real-time flow measurement preview, and printing of flow result tables.

[0062] Status display module 600: See Figure 3 It displays the current operating status of the device in real time.

[0063] Network signal: Lights up when communication with the gondola is normal;

[0064] Hanging box charging: When the voltage in the hanging box is insufficient, it will automatically charge when it returns to the horizontal position;

[0065] Inverter power-on: The light illuminates when the inverter is powered on;

[0066] Horizontal Limit: The horizontal limit indicator lights up when you press Enter;

[0067] Vertical limit: Lights up when the upper limit is reached;

[0068] Bottom Limit: The indicator light will illuminate when the lead weight 4 continues to descend after hitting the bottom;

[0069] Surface signal: The surface signal lights up when the lead weight 4 enters the water;

[0070] Flow rate signal: The light illuminates when the flow meter rotates and a flow rate signal is available;

[0071] Underwater signal: Lights up when lead fish 4 detects the riverbed.

[0072] The functions of the measurement setting module 200 are described below:

[0073] 1) Flow measurement settings: See Figure 4 The flow measurement settings are an extended operation function. They automatically read water level gauge data and generate the starting distance between the left and right vertical lines, as well as the corresponding measurement methods for each vertical line. The automatically generated measurement methods can be modified. Click the "Flow Measurement" button to enter the flow measurement settings. The flow measurement settings interface allows you to adjust the starting point, ending point, and spacing of the vertical lines. If you need to drill depth, check "Measurement Depth" (this is not necessary when using a cross-section). Then click the "Automatic Generation" button to generate the flow measurement plan. Adjust the plan as needed. To save the plan for future flow measurements, click the "Save" button, and finally click "Confirm" to load the plan. "Automatic Generation" defaults to flow meter measurement; selecting "Measurement Depth" first, then "Automatic Generation," will default to drilling depth for each vertical line; you can also manually check the box in the Depth Dialog Box to select whether to drill depth.

[0074] See Figure 5 Double-click the "Measurement Method" dialog box corresponding to each vertical line to select the measurement method. The surface method, one-point method, two-point method, three-point method, and five-point method all use propeller current meter for flow measurement without drilling depth; the borrowed water depth is only used for area calculation and not for flow velocity measurement; the actual measured water depth is only used for riverbed elevation measurement and not for flow velocity measurement; first select "Drill Depth", then select the propeller current meter measurement method, and drill depth before measuring flow for each line.

[0075] Double-clicking the "Start Point Distance" dialog box corresponding to each vertical line allows you to modify the vertical line start point distance. Double-clicking the "Water Surface Coefficient" dialog box corresponding to each vertical line allows you to modify the relevant coefficients, for example, the water surface coefficient is 0.85.

[0076] See Figure 6 If you choose to use a vertical ADCP for flow measurement, click the "ADCP" button, right-click the vertical line number, select "Insert Row" or "Delete Row" to add or delete vertical lines, modify the starting point distance and the waterside coefficient, click "Save" (or not save), click "OK", and click "Start".

[0077] For joint measurements, each vertical line can be assigned a separate number, such as... Figure 7 As shown.

[0078] 2) Preview: Click "Start," and the system will begin automatic measurement. Click "Preview" to preview the measurement data in real-time in tabular format. You can re-measure or supplement any problematic measurement points at any time, or wait for the system to complete the current measurement and view the results. If there are any discrepancies, select the vertical line that needs to be remeasured and click "Remeasure." The system will then remeasure the selected measurement points. After the system completes the current measurement, click "Save Record" to complete the current measurement.

[0079] During the flow measurement process, if a problematic measuring point is identified through real-time preview and needs to be remeasured, select the problematic vertical line or measuring point and then click "Remeasurement Start".

[0080] After the measurement is completed, click "Preview", then click "Flow Measurement Record". If you need to export the data, select the "Measurement Number" to be exported and click "Export Report" to generate the flow measurement report.

[0081] 3) Parameter settings: Modify the corresponding parameters according to the function description. The main functions to be modified include "Host computer settings", "Measurement method", "Water gauge", "Current meter parameters" and "Riverbed elevation".

[0082] Host computer settings: Configure network and flow measurement coefficients, etc. See Table 1 below for some parameter settings:

[0083] Table 1

[0084] Parameter name illustrate Range of values Flow meter height The current meter's signal height relative to the water surface -0.5~0.5 Unit: meter Buoyancy coefficient underwater signal height relative to surface signal height 0~1 Unit: meter Number of prompt tone signals How many flow rate signals correspond to one beep? 1~100 Lead weight parking level Position of the lead weight after the current measurement is completed perpendicular parking position of lead weight Position of the lead weight after the current measurement is completed Lead fish increase height The height of the lead weight above the water surface when moving between vertical lines 1~5 Unit: meter Flow rate measurement time Measurement point flow time 10~200 Unit: seconds K-value of flow meter Modify this coefficient after replacing the flow meter. C-value of flow meter Modify this coefficient after replacing the flow meter. Starting perpendicular position When generating the flow measurement scheme, start vertical position Termination of perpendicular position Termination vertical position when generating the flow measurement scheme Perpendicular spacing Spacing between perpendiculars when generating flow measurement scheme Starting to measure water depth Minimum water depth for generating vertical lines in flow measurement scheme Left side coefficient Fill in this coefficient according to the "Hydrological Standard". Right side coefficient Fill in this coefficient according to the "Hydrological Standard". Dead water edge coefficient Fill in this coefficient according to the "Hydrological Standard". Half-depth coefficient Fill in this coefficient according to the "Hydrological Standard". Water surface coefficient Fill in this coefficient according to the "Hydrological Standard". Radar coefficient This coefficient was modified after comparison with the flow meter. Water depth coefficient Fill in this coefficient according to the river conditions. Automatic flow coefficient Automatic water level measurement threshold 0.1~1 Unit: meter Number of times to penetrate Number of times for flow measurement and drilling 1~3 Automatic temperature measurement Automatic temperature switch 0~1 0: Off; 1: On Temperature measurement level Fill in this coefficient according to the river conditions. Temperature measurement vertical position Fill in this coefficient according to the river conditions. Automatic flow measurement Automatic current measurement switch 0~1 0: Off; 1: On

[0085] Measurement method: The water depth measurement range corresponding to the 1-point to 5-point method on each vertical line is set according to relevant specifications.

[0086] Water gauge: Set the water gauge number and elevation. This operating system uses the water level gauge by default to read the water level, and uses the water gauge reading to measure the flow when the automatic water level gauge fails.

[0087] Flowmeter parameters: Set the flowmeter number and K and C values ​​for easy selection during flow measurement. K value is the hydraulic pitch, and C value is the instrument constant. K and C values ​​are the core parameters of the flowmeter, directly affecting the measurement accuracy, and need to be calibrated through a standard water tank experiment.

[0088] Riverbed elevation: Enter the riverbed elevation to generate a river cross-section map.

[0089] This monitoring system has the following functions and features:

[0090] The flow measurement system boasts excellent scalability, simultaneously supporting the measurement functions of propeller current meters, ADCP, radar wave velocity meters, and electromagnetic current meters. It features automatic water level acquisition, enabling unattended automatic flow measurement based on set time and water level changes, and automatically generating corresponding measurement plans for different water level levels. It supports remeasurement and supplementary measurements in case of flow anomalies, and allows for interruption and resumption of measurement in case of unexpected events during the measurement process. Communication between velocity, surface, and riverbed signals utilizes a digital signal transmission protocol. The system employs a client / embedded server mode, with the embedded server running a stable and reliable Linux operating system, enabling remote control and image transmission without the need for third-party control software. System reports are automatically generated, ensuring accuracy and reliability. After each flow measurement, the system automatically generates data reports in a format fully compliant with hydrological standards, ready for direct compilation. Before report generation, any measurement point can be remeasured at any time if there are objections. Once generated, the data cannot be modified, preventing tampering and ensuring the authenticity and reliability of the measurement data.

[0091] The fully automated mechatronics flow measurement system, with fully automated measurement and control software as its core and through technological upgrades to the hardware system, enables on-site measurement, calculation, processing, and analysis. It automatically collects data signals such as water level, distance from the starting point, water depth, and flow velocity; automatically calculates hydrological elements such as water surface width and cross-sectional flow rate; and can output flow data that is compatible with standardized compilation programs. While meeting the requirements of flow measurement specifications, it shortens the measurement time, reduces labor intensity, lowers the incidence of human error and hardware failure, and improves the stability and reliability of the measurement, thus promoting the reform of measurement and reporting methods and the modernization of hydrology.

[0092] See Figure 8 Radar current measurement technology is based on the Doppler effect, named after the Austrian physicist Christian Johann Doppler in recognition of his contributions to the field. In acoustics, when there is relative motion between a sound source and a receiver (including probes and reflectors), the frequency of the echo changes; this frequency change is called frequency shift, or the Doppler effect. When a radar current meter moves relative to a body of water at a relative velocity V, the frequency of the electromagnetic waves received by the radar current meter differs from the frequency of the electromagnetic waves it emits; this frequency difference is called the Doppler frequency shift. By analyzing the relationship between the frequency shift and the velocity V, the flow velocity at the fluid surface can be calculated.

[0093] See Figure 9The radar flow meter integrates a radar level gauge and a radar velocity gauge to measure the distance to the water surface and the flow velocity. The radar level gauge antenna beam angle is 11×11°, and the radar antenna angle is 14×32°. When the level gauge illuminates the water surface, the illumination area is similar to a circle; when the radar velocity gauge illuminates the water surface, the illumination area is similar to an elliptical region.

[0094] See Figure 10 By using pre-set cross-sectional parameters and based on the hydraulic model built into the radar flowmeter, the measured surface velocity is converted into the cross-sectional average velocity. Based on the measured liquid level, the radar flowmeter, combined with the cross-sectional geometric parameters, automatically calculates the cross-sectional area, and then uses the velocity-area method formula to determine the flow rate. Finally, the water level, cross-sectional average velocity, and flow rate are transmitted to the data management platform.

[0095] Radar flow meters, as a non-contact flow velocity measurement device, are characterized by their ability to measure fluid flow over long distances without direct contact with the water body. When measuring flow velocity, the device is unaffected by factors such as water surface conditions, floating debris, water quality, and flow regime. Under conditions of high flood levels and high sediment loads, radar flow meters will replace contact-based flow measurement devices such as acoustic time-of-flight methods for monitoring flow rates in channels and rivers.

[0096] However, radar flow meters primarily measure the surface velocity of water flow, and their performance in low-speed measurements is not ideal, with a relatively high low-speed end in their measurement range, typically above 0.3 m / s. In extremely smooth water conditions, even at high flow velocities, the instrument may malfunction due to insufficient reflected signals. Furthermore, the speed of waves and floating objects does not match the surface velocity of the water. This difference varies depending on water flow conditions, the characteristics of the floating objects, and wind speed and direction, leading to measurement errors that cannot be ignored. In addition to moving with the water flow, waves and floating objects also undergo their own motion, which further introduces additional measurement errors.

[0097] See Figure 11 The basic principle is to use a pair of ultrasonic transducers. Ultrasonic waves propagate at a uniform speed in liquids or solids, let's call it c. The fluid velocity is V. Two ultrasonic transducers for transmitting and receiving are placed at points A and B. The length of the line connecting A and B (the sound channel) is L, and the angle between the line and the direction of the fluid velocity is θ.

[0098] Ultrasonic waves are emitted by probe A and received by probe B. The propagation time is T. up The ultrasonic wave is emitted by probe B and received by probe A. The propagation time is T. down .

[0099]

[0100] θ: Channel angle, the angle between the channel and the flow channel axis;

[0101] L: Channel length, the actual path of ultrasonic signal propagation.

[0102] The main equipment of the acoustic full-section time-of-flight flow monitoring system is the acoustic full-section time-of-flight flow meter, which includes the main unit, slave units, matrix sonar transducers (frequency 200kHz, 90kHz, 28kHz), high-precision time synchronization device, wireless transmission, and flow totalizer. Other equipment includes water level gauges, equipment installation kits, power supply systems (mains power or solar power), and dedicated equipment brackets.

[0103] Measurements are achieved by having two sets of equipment installed at workstations on both banks of the river work together. Typically, the equipment is installed at a 45-degree angle to the direction of the river, and the two units alternately transmit modulated ultrasonic signals. The flow velocity across the entire river cross-section is determined by the difference in the time it takes for each unit to receive the other's signal.

[0104] After the sonar signal is emitted from the host, within a 45-degree angle range, the direct acoustic wave and the multipath wave reverberate, and the slave device acquires the complete signal. After exchange, the slave device's acoustic wave passes through the same channel and is received by the host device. The acoustic signal can basically reflect the velocity field properties of the water layer at the transducer elevation. Through the representative model of water layer velocity, the velocity at a certain water depth can be calculated. Generally, one transducer can represent a water depth of about 4 meters (which varies slightly depending on the cross-sectional width and the degree of cross-sectional regularity).

[0105] The flow velocity algorithm mainly uses the water level area method for calculation. Based on the distribution pattern of water flow velocity along the cross section, cross section characteristics, water level, virtual flat bottom channel coefficient, transducer installation height, and the measured flow velocity of the time difference instrument, the virtual vertical flow velocity is calculated, and then the cross section flow rate is calculated according to the flow meter method.

[0106] The fluid flow velocity V of multiple sound channels was measured. i (i=1,2,…,k), where k is the number of vocal tracts, by combining mathematical functional relationships, an estimate of the average flow velocity of the channel / river can be obtained. Multiplying this by the flow area A yields the volumetric flow rate qv.

[0107] qv= A ;

[0108] Its characteristics are:

[0109] Installed on both sides of the channel, installation is convenient when dry, but more difficult when wet. Post-installation maintenance: Debris may cover the probe, requiring regular maintenance. It has a large measurable cross-sectional area; employs wireless communication and a high-precision time synchronization system; the system is highly resistant to sand content; suitable for cross-sections under turbulent conditions; and can be used in multi-layer systems to measure stratified flow velocities and calculate the total cross-sectional flow.

[0110] The disadvantages are that unstable cross sections should be avoided; a certain water depth is required; the sensor is at risk of being damaged by debris; and the acoustic signal is affected by certain factors such as suspended matter, weeds, bubbles, temperature, and salinity.

[0111] ADCP-based flow measurement method

[0112] Sound waves exhibit a unique effect: when a sound wave approaches an object, the frequency perceived by the object is higher than the frequency of the emitted wave; conversely, when the sound wave moves away from the object, the frequency perceived is lower than the frequency of the emitted wave. This is the well-known acoustic Doppler shift effect, and ADCP (Advanced Digital Conversion) utilizes this principle to measure water flow velocity. ADCP emits short pulses of sound waves at a fixed frequency into the water. These pulses are backscattered by scattering agents (plankton, sediment, etc.) in the water. ADCP receives the Doppler shift of the echo signals, processes them to obtain the flow velocity, and measures the relative motion within the water, including the velocity of the water relative to the instrument and the velocity of the instrument within the water. The principle can be expressed by the following formula:

[0113] ,

[0114] In the formula F is the Doppler frequency shift (Hz); F is the transmitted wave frequency shift (Hz); V is the water flow velocity along the direction of the sound beam (m / s); C is the sound wave propagation speed in water (m / s).

[0115] ADCP continuously emits and receives sound waves into the water body, thus measuring all points along the vertical line. Combined with the water depth measured by the lateral depth device, the unit flow rate of that vertical line is obtained. When ADCP measures from the beginning to the end of the cross-section, the flow rate of the entire cross-section is measured.

[0116] As can be seen from the formula based on the basic principle of ADCP measurement, the factors affecting the flow velocity V include: Acoustic Doppler frequency shift, Fs, transmission frequency, c, the speed of sound in water. The speed of sound in water is usually a constant value, but the temperature and salinity of the water have a certain influence on this value. In the influence of Fd, the frequency of the transmitted wave is fixed, so the only factor affecting the flow velocity V is the receiving frequency. Therefore, from the perspective of measurement principle, the sound wave receiving device in ADCP instrument equipment is the key factor affecting the accuracy of flow velocity measurement. The material and manufacturing process of the equipment determine the measurement accuracy of the equipment.

[0117] The application of the cruise ADCP test method in channels (especially high-flow water conveyance channels) is relatively rare. The main difficulty is that high-flow water conveyance channels are often accompanied by unfavorable conditions such as high flow velocity. Relying solely on test personnel at both ends of the channel can easily cause the hull to tilt or even capsize, making on-site testing difficult and posing significant safety risks. Furthermore, the method is not effective in areas with high sediment content or unstable riverbeds.

Claims

1. An intelligent hydrological monitoring system based on the Internet of Things, characterized in that: The system includes a host computer, a flow measurement control platform, a network communication module, a PLC controller, a mechanical system, and a flow measurement system. The flow measurement control platform runs on the host computer and communicates with the PLC controller and the flow measurement system via the network communication module. The PLC controller identifies the commands from the flow measurement control platform and controls the actions of the mechanical system. The mechanical system undertakes the actions required by the flow measurement system during flow measurement. The flow measurement system acquires hydrological monitoring data and uploads it to the flow measurement control platform. The flow measurement system can select flow measurement methods at different measurement points within the same cross section for joint flow measurement as needed; Based on the hydrological data of the same measuring point within the same cross section obtained by the joint flow measurement, the deviation between different flow measurement methods is calculated, and the current hydrological conditions are given a reverse warning.

2. The IoT-based intelligent hydrological monitoring system according to claim 1, characterized in that: The flow measurement system includes ADCP flow measurement, radar flow measurement, time-difference ultrasonic flow measurement, propeller current meter, and field water level gauge.

3. The IoT-based intelligent hydrological monitoring system according to claim 1, characterized in that: The mechanical system includes a triangular bridge (1), an electric winch (2), a gantry crane (3), lifting equipment, and video acquisition. The triangular bridge (1) is erected on both banks of the river / channel to be measured. The electric winch (2) is fixedly installed on the triangular bridge (1). The gantry crane (3) is slidably installed on the triangular bridge (1). The electric winch (2) drives the gantry crane (3) to move back and forth across the river / channel at the bottom of the triangular bridge (1). The lifting equipment is fixedly installed on the triangular bridge (1) and vertically lifted by the lifting guide wheel carrying the equipment used for hydrological measurement. The video acquisition is used to obtain real-time dynamics of the on-site environment.

4. The IoT-based intelligent hydrological monitoring system according to claim 2, characterized in that: The flow measurement control platform consists of a flow measurement dynamic simulation module (100), a measurement setting module (200), a manual / automatic operation module (300), a video operation module (400), a video display module (500), and a status display module (600). The flow measurement dynamic simulation module (100) is used to intuitively display the panoramic view and enlarged view of the river cross section and dynamically simulate the entire process of flow measurement at the flow measurement cross section. The measurement setting module (200) is used to complete the functions of parameter setting, measurement setting, real-time preview, and printing measurement reports. The manual / automatic operation module (300) is used to complete the manual and automatic switching operation to control the operation of the flow measurement equipment. The video operation module (400) is used to control the camera with pan-tilt unit to rotate up, down, left, and right to obtain real-time dynamic images of the surrounding environment. The video display module (500) is used to display the video images collected by the video operation module (400). The status display module (600) is used to display the current operating status of each device in real time.

5. The IoT-based intelligent hydrological monitoring system according to claim 1, characterized in that: The network communication module is divided into an internal network and an external network. The internal network is used for interconnection between devices within the flow measurement system, while the external network is used for data communication between the flow measurement system and the flow measurement control platform, and between the mechanical system and the flow measurement control platform. Internal network data transmission is completed by microwave communication, while external network data transmission is realized by the Internet or a private network.

6. The IoT-based intelligent hydrological monitoring system according to claim 4, characterized in that: The main functions of the measurement setting module (200) include flow measurement settings, parameter settings, real-time flow measurement preview, and printing of flow result tables.

7. The IoT-based intelligent hydrological monitoring system according to claim 6, characterized in that: After the flow measurement settings are completed, the flow measurement control platform automatically reads the water level gauge data and generates the starting distance of the left and right vertical lines, automatically generates the measurement method for the corresponding vertical lines, and can modify the automatically generated measurement method.

8. The IoT-based intelligent hydrological monitoring system according to claim 6, characterized in that: The parameter settings include setting the water depth measurement range corresponding to the 1-5 point method on each vertical line.

9. The IoT-based intelligent hydrological monitoring system according to claim 6, characterized in that: During the real-time preview of the flow measurement, a real-time warning is issued for problematic measurement points, and retesting or supplementary testing is performed.

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