Intelligent hydrological monitoring system based on Internet of Things

Abstract

The invention 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 (Programmable Logic Controller), a mechanical system and a flow measurement system, the flow measurement control platform controls the PLC and the flow measurement system through a network communication module in an instruction mode, the flow measurement system is used for obtaining hydrological monitoring data and uploading the hydrological monitoring data to the flow measurement control platform, and the flow measurement system comprises ADCP flow measurement, radar flow measurement, time difference method ultrasonic flow measurement, a propeller flow meter and a field water level gauge. And the flow measurement system selects a flow measurement method at different measurement point positions in the same section as required to carry out combined flow measurement. According to the invention, a plurality of flow measurement methods are carried through the flow measurement system and are uniformly controlled and scheduled by the flow measurement control platform, so that the monitoring system has good expansibility. On the basis, corresponding flow measurement schemes can be automatically generated according to different water level levels, advantages and disadvantages of the flow measurement methods are complementary, and the detection precision is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrological monitoring, in particular to an intelligent hydrological monitoring system based on the Internet of Things. BACKGROUND

[0002] At present, the water resources management of each basin is facing challenges such as insufficient precision of water distribution, non-uniformity of measurement technical standards, and low level of intelligentization of monitoring system. The primary task is to improve the precision of water diversion measurement. However, due to the complex working conditions of rivers in the basin, such as high silt content, turbid water flow, channel silt, more sediment, changing channel section, and water intake working conditions, the traditional measurement methods are greatly affected, and there is a large measurement error.

[0003] With the development of the Internet of Things and big data technology, the demand for intelligent scheduling and sustainable utilization of water resources has emerged. It is necessary to build a perfect monitoring network, improve the coverage range, establish a real-time dynamic water quantity monitoring system, realize comprehensive data collection and efficient transmission, promote the informatization upgrade of the monitoring and measurement system, rely on big data analysis, cloud computing and artificial intelligence technology, research and utilize intelligent water quantity monitoring platform, improve the automatic processing capacity of data, reduce human intervention, and improve management efficiency.

[0004] The present application aims to build an intelligent hydrological monitoring platform and a high-precision hydrological monitoring system. SUMMARY

[0005] In view of the deficiencies of the existing hydrological monitoring system in the background art, the present application provides an intelligent hydrological monitoring system based on the Internet of Things, which has the advantages of unmanned automatic flow measurement, combined flow measurement with multiple flow measurement methods to improve measurement accuracy, and automatic generation of real and reliable data reports, solving the technical problems raised in the background art.

[0006] The present application provides the following technical solution: an intelligent hydrological monitoring system based on the Internet of Things, comprising 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 is running on the upper computer, the flow measurement control platform realizes data intercommunication with the PLC controller and the flow measurement system through the network communication module, the PLC controller is used for identifying the instructions of the flow measurement control platform and controlling the action of the mechanical system, the mechanical system is used for bearing the action demand of the flow measurement system during flow measurement, and the flow measurement system is used for obtaining hydrological monitoring data and uploading the flow measurement control platform.

[0007] Preferably, the flow measurement system comprises ADCP flow measurement, radar flow measurement, time difference method ultrasonic flow measurement, propeller current meter and field water level meter, and the flow measurement system selects flow measurement methods as needed for combined flow measurement at different measurement points in the same section.

[0008] Here, as needed, the advantages and disadvantages of each flow measurement method and the applicable hydrological working conditions can be selected, such as the radar method which is suitable for measuring the flow velocity of the water surface and is suitable for measuring relatively clean and calm water surface; the time difference method which is suitable for measuring high sediment content, turbulent flow and large cross-section range; and the ADCP flow measurement which is suitable for measuring high-precision, large-flow and low-sediment content. For example, for the case of small water surface waves, 1-5 meters of water depth, low sediment content, 5-10 meters of high sediment content, and laminar flow, a combined detection can be set up, the radar method is used for the water surface, the ADCP flow measurement is used for the 1-5 meter measuring point, and the time difference method is used for the 5-10 meter flow measurement. Thus, the respective advantages of the flow measurement methods are utilized for combined detection to further improve the precision of the final cross-section flow velocity, flow and other hydrological data based on the upper limit of the precision of each detection device.

[0009] Preferably, the deviation between different flow measurement methods is calculated based on the hydrological data of the same measuring point in the same cross-section obtained by the combined flow measurement.

[0010] The deviation refers to the deviation of the data obtained by different flow measurement methods at the same measuring point in the same cross-section. The warning result is based on the factors of different flow measurement methods used at the measuring point, such as the above-mentioned 1-5 meter measuring point using ADCP flow measurement and 5-10 meter using time difference method. The factor basis is the difference in sediment content of 1-5 meter and 5-10 meter laminar flow. At this time, if the deviation of the ADCP flow measurement result from the time difference method flow measurement result is smaller, it means that the entire laminar flow has uniform sediment content, and if the deviation is larger, it means that the laminar flow has obvious difference in sediment content. The combined detection result is closer to the high-precision requirement, and can be further confirmed in combination with the monitoring video.

[0011] Preferably, the mechanical system includes a triangular bridge, an electric winch, a traveling frame, a lifting device, and a video acquisition. The triangular bridge is erected on the two side embankments of the river / channel to be measured. The electric winch is fixedly installed on the triangular bridge. The traveling frame is slidably installed on the triangular bridge. The electric winch drives the traveling frame to reciprocally walk across the river / channel at the bottom end of the triangular bridge. The lifting device is fixedly installed on the triangular bridge and vertically lifts the equipment for hydrological measurement through the lifting guide wheel. The video acquisition is used to obtain real-time dynamics of the on-site environment.

[0012] Preferably, the flow measurement control platform is composed 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 state display module, the flow measurement dynamic simulation module is used for visually displaying a river section panoramic view and an enlarged view, and dynamically simulating the whole process of flow measurement of the flow measurement section, the measurement setting module is used for completing parameter setting, measurement setting, real-time preview and printing measurement report functions, the manual / automatic operation module is used for completing manual / automatic switching operation to control the operation of flow measurement equipment, the video operation module is used for controlling the up-down and left-right rotation of a camera with a holder to obtain real-time dynamic pictures of the surrounding environment, the video display module is used for displaying the video pictures collected by the video operation module, and the state display module is used for displaying the current operation state of each device in real time.

[0013] Preferably, the network communication module is divided into an intranet and an extranet, the intranet is used for interconnection between internal devices of the flow measurement system, and the extranet 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. The intranet data transmission is completed by microwave communication, and the extranet data transmission is realized by the Internet or a special network.

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

[0015] Preferably, after the flow measurement setting is completed, the flow measurement control platform automatically reads water level meter data and generates left and right vertical line starting point distances, automatically generates the measurement method of the corresponding vertical line, and can modify the automatically generated measurement method.

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

[0017] Preferably, in the flow measurement real-time preview process, the real-time warning is performed on the problematic measurement points, and the re-measurement and supplementary measurement operations are performed.

[0018] The present application has the following beneficial effects: 1. The present application has an automatic water level collection function, the flow measurement system can automatically measure flow without manual operation according to the set time and the set water level change, and can automatically generate a corresponding flow measurement scheme according to different water level levels.

[0019] 2. The present application carries multiple flow measurement methods through the flow measurement system, and is uniformly controlled and scheduled 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, so that the advantages and disadvantages of each flow measurement method are complementary, a solution for improving measurement accuracy is provided from the flow measurement scheme level, and the detection accuracy is further improved beyond the upper limit of the accuracy of the equipment used by each existing flow measurement method.

[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; Figure 2 This is a schematic diagram of the mechanical system structure layout of the present invention; Figure 3 This is a schematic diagram of the layout of the flow measurement and control platform modules of the present invention; Figure 4 This is a schematic diagram of the measurement settings window of the present invention; Figure 5 For the present invention Figure 4 A schematic diagram of the window for displaying measurement methods in China; Figure 6 For the present invention Figure 4 A schematic diagram showing the window for adding and subtracting vertical lines after executing ADCP; Figure 7 For the present invention Figure 4 A schematic diagram showing the adjustment of the measurement methods for each vertical line. Figure 8 This is a schematic diagram of radar-based current meter measurement in the appendix of this invention; 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; Figure 10 This is a schematic diagram of radar flow measurement in the appendix of this invention; Figure 11 This is a schematic diagram of the instrument distribution of the time difference method system in the appendix of this invention; Figure 12 For the present invention Figure 3 A partially enlarged schematic diagram of the dynamic simulation module for medium-speed flow measurement; Figure 13 For the present invention Figure 3 A magnified view of a portion of the status display module.

[0023] In the figure: 1, triangular bridge; 2, electric winch; 3, trolley frame; 4, lead fish; 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, state display module. DETAILED DESCRIPTION

[0024] Please refer to Figure 1-Figure 3 The intelligent hydrological monitoring system based on the Internet of Things includes a host computer, a flow measurement control platform, a network communication module, a PLC controller, a mechanical system, and a flow measurement system.

[0025] The host computer is a computer or an embedded server module installed with a running executable program. The flow measurement control platform is mounted in the computer or the embedded server module and can run. The embedded server can use a Linux operating system, which is stable and reliable.

[0026] The mechanical system and the flow measurement system are physical devices installed at the hydrological monitoring site.

[0027] The mechanical system includes a triangular bridge 1, an electric winch 2, a trolley frame 3, hoisting equipment, and video acquisition. The triangular bridge 1 is a steel structure truss structure composed of two upright columns and a truss. The two upright columns are respectively erected on the two sides of the river channel to be measured, and are fixed to the ground by reinforced concrete and bolts. The truss is erected at the top of the two upright columns across the river channel. The electric winch 2 is fixedly installed on one upright column of the triangular bridge 1. The trolley frame 3 is slidingly installed at the bottom end of the truss of the triangular bridge 1. The electric winch 2 drives the trolley frame 3 to reciprocally walk horizontally at the bottom end of the truss of the triangular bridge 1 through a transmission chain or a steel cable and the like transmission mechanism. The hoisting equipment is fixedly installed on one upright column of the triangular bridge 1. The hoisting equipment and the electric winch 2 are installed on the same upright column. The bottom end of the trolley frame 3 is rotatably installed with a hoisting guide wheel. The steel rope of the hoisting equipment passes through the hoisting guide wheel and hangs the equipment used for hydrological measurement. The video acquisition is a camera that acquires the dynamic of the on-site environment. Multiple groups can be arranged, such as tracking and monitoring the external river channel and the flow measurement equipment, monitoring the driving device, monitoring the river channel condition in front of the flow measurement, and the like. The external river channel monitoring camera is an infrared network high-definition intelligent ball machine, which realizes manual monitoring of the river channel in all directions and automatic tracking function of the movement track of the flow measurement equipment. The camera is a controllable pan-tilt device, which can realize up-down and left-right rotation control. The electric winch 2 is used to drive the flow measurement equipment. A grating encoder is installed on the driving shaft of the winch to realize accurate positioning of the trolley frame 3 / flow measurement equipment.

[0028] The flow measurement system includes ADCP flow measurement, radar flow measurement, time difference method ultrasonic flow measurement, propeller current meter, and on-site water level meter.

[0029] ADCP flow measurement is a flow test method based on acoustic Doppler current profiler; radar flow measurement is a flow test method based on radar flow meter; time difference method ultrasonic flow measurement is a flow test method based on acoustic full-section time difference method flow meter; propeller current meter is only used for flow velocity measurement and does not punch deep (i.e. does not measure water depth); field water level meter is a general device for measuring current water level. For specific measurement principles and advantages and disadvantages of each flow measurement, please refer to the appendix content of the subsequent application.

[0030] The device for ADCP flow measurement is mounted on one end of the steel rope of the hoisting device, controlled by the hoisting device to realize lifting in water, and translated in horizontal span under the drive of the trolley frame 3; the device for radar flow measurement is installed on the truss of the triangular bridge 1; the device for time difference method ultrasonic flow measurement is installed on both sides of the river / channel section where the triangular bridge 1 is located. The driving source of the hoisting device and the electric winch 2 can be provided by two 1.5kw servo motors, the lead fish 4 for ADCP flow measurement weighs 50kg, and for horizontal movement of the trolley frame 3, automatic parking is set at the maximum and minimum starting points, and automatic parking is set at the highest and river bottom when the lead fish 4 is vertically lifted by the hoisting device, the braking time of the lead fish 4 is less than 1s, and automatic parking control is preset for point positioning in horizontal and vertical movement.

[0031] Among them, when the vertical ADCP flow measurement, first, the mechanical system electric winch 2 drives the lead fish 4 to run above the flow vertical line, and then the hoisting device drives the lead fish 4 to be below the water surface, and sends the water surface signal to the flow control platform, when the river bottom detection device detects that the lead fish 4 has fallen to the river bottom, the lead fish 4 stops descending and sends the river bottom signal to the flow control platform, the electric winch 2 lifts the lead fish 4 above the water surface, and finally the lead fish 4 is put into the water below the water surface for flow measurement.

[0032] The flow control platform controls the PLC controller through the network communication module to control / drive the mechanical system to perform operation, and realizes instruction control and data intercommunication between the flow control platform and the flow measurement system through the communication module. The PLC controller is integrated into the flow control box 5 and installed on the column of the triangular bridge 1.

[0033] The flow control platform is composed of flow dynamic simulation module 100, measurement setting module 200, manual / automatic operation module 300, video operation module 400, video display module 500 and state display module 600.

[0034] The flow measurement dynamic simulation module 100 is used for intuitively displaying the river section panoramic view and the enlarged view, and dynamically simulating the whole process of the flow measurement section flow measurement, including: real-time display of the flow measurement equipment position at the flow measurement section, real-time display of the positions of each measuring point, completion of the measuring point, and flow velocity of the measuring point, real-time display of the key data in the flow measurement process, and the function of manually changing the position of the slider (the display key simulated by the flow measurement equipment on the flow measurement dynamic simulation module 100) to display the corresponding start point distance and water depth.

[0035] The measurement setting module 200 is used for completing the parameter setting, measurement setting, real-time preview, and printing of the measurement report.

[0036] The manual / automatic operation module 300 is used for completing the manual and automatic switching operation, the high and low speed switching operation of the frequency converter, the car out and car back operation of the equipment, and the folding and unfolding operation of the flow measurement equipment, etc. If automatic flow measurement is required, the “manual / automatic” button is clicked to switch to the automatic state. The automatic flow measurement is to select different flow measurement methods according to the different working conditions of the predetermined settings.

[0037] The video operation module 400 is used for controlling the up, down, left and right rotation of the camera with a pan-tilt head, so as to obtain the real-time dynamic picture of the surrounding environment.

[0038] The video display module 500 is used for displaying the video picture collected by the video operation module 400. Each camera occupies an independent picture, and each image can be zoomed in or out, so as to facilitate the observation of the flow measurement condition.

[0039] The state display module 600 is used for real-time display of the current equipment running condition.

[0040] The network communication module is divided into an internal network and an external network. The internal network refers to a small local area network inside the flow measurement system, and the external network refers to the data communication of the flow measurement system, the mechanical system and the flow control platform. The data transmission in the network is completed by microwave communication, and the connection with external data is realized by the Internet or a special network. Thus, the remote operation is realized, and the remote setting and issuing of the flow measurement scheme can be realized, including the water level, the start point distance, the velocity and depth vertical line, the water depth, the single line measurement time and other parameters. The server mode can not only realize the remote flow measurement function, but also can realize the remote debugging, remote assistance, automatic updating and other functions.

[0041] The measurement control platform is loaded in the host computer or embedded server module, runs, first checks the on-site environment based on the video operation module 400 and the video display module 500, then sets the measurement parameters based on the measurement setting module 200, then switches between manual and automatic operation based on the manual / automatic operation module 300, and then operates the electric winch 2, the hoisting equipment, and the measurement system, and feeds back the obtained parameters to the measurement dynamic simulation module 100 for intuitive display. The water level collection has two collection functions: collecting the on-site water level meter data and using the water depth to participate in the flow calculation; using the river bottom detection device on the lead fish 4 to participate in the flow calculation, and updating the cross-section data after the actual water depth is completed. After the comprehensive measurement is completed, the measurement setting module 200 exports the parameter results in the form of a standardized report. At this point, the intelligent hydrological monitoring platform and the hydrological monitoring system are completed.

[0042] Because the measurement system is equipped with multiple measurement methods and is uniformly controlled and scheduled by the measurement control platform, the monitoring system has good expandability. On this basis, a corresponding measurement scheme can be automatically generated according to different water level levels, the advantages and disadvantages of each measurement method are complementary, a solution for improving measurement accuracy is provided from the measurement scheme level, and the detection accuracy is further improved beyond the upper limit of the accuracy of the equipment used by each measurement method.

[0043] The system has an automatic water level collection function, the measurement system can automatically measure without manual intervention according to the set time and set water level change, the system report is automatically generated and accurate and reliable. The system generates a data report after the measurement is completed, the report format completely meets the requirements of the hydrological specification, and can be directly used for compilation. Before the report is generated, if there is any objection to the measurement point, any measurement point can be re-measured at any time, once the report is generated, the data cannot be modified to prevent human tampering with the original data and ensure the authenticity and reliability of the data measurement. Under the premise of meeting the requirements of the flow measurement specification, the measurement duration is shortened, the labor intensity is reduced, the human operation error and the hardware failure rate are reduced, the stability and reliability of the measurement are improved, and the reform of the measurement and reporting method and the modernization of hydrology are promoted. By uploading the data report that cannot be changed by humans to the server to establish a data sharing mechanism, multi-department collaborative management can be promoted, information silos can be reduced, and the transparency of water resource allocation can be improved.

[0044] The preferred embodiments are supplemented by the interface operation of the measurement control platform to supplement the functions to be achieved by the system during monitoring.

[0045] The measurement control platform is opened by the computer, the interface is as shown in Figure 3 There are six areas.

[0046] Flow measurement dynamic simulation module 100: intuitively display the river section simulation panoramic view and section zoomed-in view (double-click the section simulation panoramic view), dynamically simulate the whole process of section flow measurement during flow measurement, including: real-time display of the lead fish 4 at the flow measurement section position, real-time display of the positions of each measurement point, completion of the measurement point, and main data such as flow velocity of the measurement point, and the function of viewing the corresponding start distance and water depth by sliding the mouse to the corresponding vertical line position.

[0047] Video operation module 400 and video display module 500: three cameras are installed in this embodiment, and the installation positions and functions are as follows: two infrared network high-definition intelligent ball machines are installed outside the cableway house, which can realize all-around monitoring of the external river and the river in front of the flow measurement; one gun machine is installed inside the hanging box, which can track and monitor the lead fish 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, enlarged and reduced.

[0048] Manual / automatic operation module 300: mainly completes manual and automatic switching operation, high and low speed switching operation of the frequency converter, car out and car back operation of the hanging box, lifting operation of the lead fish 4 and the flow meter, etc. According to the actual situation, click the “manual / automatic” button to switch to manual or automatic state. If automatic flow measurement is required, click the “manual / automatic” button to switch to automatic state. Click the “one-key return” key to avoid floating objects or return to the initial position in emergency.

[0049] Measurement setting module 200: the main functions include flow measurement setting, parameter setting, flow measurement real-time preview, and printing of flow result table.

[0050] State display module 600: refer to Figure 3 for real-time display of the current equipment running state.

[0051] Network signal: lit when the communication with the hanging box is normal; Hanging box charging: when the hanging box voltage is insufficient, it will automatically charge when returning to the horizontal position; Frequency power-on: lit when the frequency converter is connected to the power supply; Horizontal limit: lit when the horizontal limit acts during car back; Vertical limit: lit when rising to the upper limit position; Touch bottom limit: lit when the lead fish 4 continues to drop after touching the bottom; Water surface signal: lit when the lead fish 4 enters the water; Flow velocity signal: lit when the flow meter rotates and there is a flow velocity signal; Water bottom signal: lit when the lead fish 4 detects the river bottom.

[0052] Among them, the functions in the measurement setting module 200 are as follows: 1) Flow measurement setting: refer to Figure 4, the flow measurement setting belongs to the extended operation function, which automatically reads the water level meter data and generates the left and right vertical line starting point distance, automatically generates the corresponding vertical line measurement method, and can modify the automatically generated measurement method. Click the "flow measurement" button to enter the flow measurement setting. The flow measurement setting interface can adjust the vertical line starting point, vertical line endpoint and vertical line spacing. If you need to punch, select "measure punch" (borrow section does not need to select "measure punch"), then click the "auto generate" button to generate the flow measurement scheme. According to the demand, adjust the flow measurement scheme, if you want to save this scheme, click the "save" button, and then click "confirm" to load the flow measurement scheme. The default flow measurement of the flowmeter is "auto generate"; first select "measure punch", then select "auto generate" to default each vertical line to punch; You can also manually punch "√" in the punch dialog box to select whether to punch.

[0053] Referring to Figure 5 , double-click the "measurement method" dialog box corresponding to each vertical line to select the measurement method. Water surface method, one-point method, two-point method, three-point method, and five-point method are all propeller flowmeter flow measurement, without punching; Borrowed water depth only participates in area calculation, without flow velocity measurement; The measured water depth only measures the river bottom elevation, without flow velocity measurement; First select "punch", then select the propeller flowmeter measurement method, and each appears first punch and then flow measurement.

[0054] Double-click the "starting point distance" dialog box corresponding to each vertical line to modify the vertical line starting point distance. Double-click the "water edge coefficient" dialog box corresponding to each vertical line to modify the relevant coefficient, for example: the water surface coefficient is 0.85.

[0055] Referring to Figure 6 , if you choose to use 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 water edge coefficient, click "save" (you can also not save), click "confirm", and click "start".

[0056] For joint measurement, each vertical line number can be set separately, as shown in Figure 7 .

[0057] 2) Preview: Click "Start" to start automatic measurement, click "Preview" to preview real-time measurement data in table form, and you can perform re-measurement, supplementary measurement and other operations on problematic measurement points at any time, or wait for the system to complete the flow measurement, and then view the flow measurement results. If you disagree, select the vertical line you want to re-measure, click "re-measure", and the system will re-measure the selected measurement points. After the system completes the flow measurement, click "save record" to complete the flow measurement.

[0058] During the flow measurement, if the problem of the measuring point is found through real-time preview, the problematic vertical line or measuring point is selected and then the "re-measurement start" is clicked.

[0059] After the measurement is completed, "preview" is clicked and then "flow measurement record" is clicked. If the data needs to be exported, the "measurement number" to be exported is selected and "export report" is clicked to generate the flow measurement report.

[0060] 3) Parameter setting: the modification of corresponding parameters is completed according to the function description. The main modification functions include "host computer setting", "measurement method", "water gauge", "current meter parameter" and "river bottom elevation" and the like.

[0061] Host computer setting: the network and flow measurement coefficient and the like are set. Some parameter settings refer to Table 1 below: Table 1 Parameter name Explanation Value range Height of current meter Height of current meter relative to water surface signal -0.5~0.5 Unit: meter Buoyancy coefficient Height of water bottom signal relative to water surface signal 0~1 Unit: meter Number of prompt signals How many current signals correspond to one prompt sound 1~100 Horizontal position of lead fish parking Position of lead fish stopping after completion of current measurement Vertical position of lead fish parking Position of lead fish stopping after completion of current measurement Lifting height of lead fish Height of lead fish moving between vertical lines from water surface 1~5 Unit: meter Current measurement time Time of measuring point current measurement 10~200 Unit: second K value of current meter Modify this coefficient after replacing current meter C value of current meter Modify this coefficient after replacing current meter Starting vertical line position Starting vertical line position when generating current measurement scheme Termination vertical line position Termination vertical line position when generating current measurement scheme Vertical line spacing Spacing between vertical lines when generating current measurement scheme Starting water depth Minimum water depth of vertical line when generating current measurement scheme Left water edge coefficient Fill in this coefficient according to Hydrological Specification Right water edge coefficient Fill in this coefficient according to Hydrological Specification Dead water edge coefficient Fill in this coefficient according to Hydrological Specification Half-depth method coefficient Fill in this coefficient according to Hydrological Specification Water surface method coefficient Fill in this coefficient according to Hydrological Specification Radar method coefficient Modify this coefficient after comparing with current meter Water depth measurement coefficient Fill in this coefficient according to river condition Automatic current measurement coefficient Automatic current measurement water level threshold 0.1~1 Unit: meter Number of sounding Number of sounding for current measurement 1~3 Temperature measurement automatic Automatic temperature measurement switch 0~1 0: off; 1: on Temperature measurement horizontal position Fill in this coefficient according to river condition Temperature measurement vertical position Fill in this coefficient according to river condition Current measurement automatic Automatic current measurement switch 0~1 0: off; 1: on Measurement method: the water depth flow measurement range corresponding to the 1-point-5-point method on each vertical line is set according to the relevant specifications.

[0062] Water gauge: the water gauge number and water gauge elevation are set. The default operation system uses the water level meter to read the water level. When the automatic water level meter fails, the water gauge reading is used to measure the flow.

[0063] Current meter parameter: the current meter number and K, C values are set for the convenience of selection during the flow measurement. The K value is the hydraulic pitch and the C value is the instrument constant. The K, C values are the core parameters of the current meter and directly affect the measurement accuracy. The standard tank experiment needs to be calibrated.

[0064] River bottom elevation: the river bottom elevation is input to generate the river section map.

[0065] The monitoring system has the following functions and characteristics: The flow measurement system has good scalability and can simultaneously support functions such as propeller current meter, ADCP, radar wave speed meter and electromagnetic current meter measurement; the system has an automatic water level acquisition function, the flow measurement system can automatically measure the flow without manual intervention according to the set time and set water level change, and can automatically generate a corresponding flow measurement scheme according to different water level levels; the system has a re-measurement, supplementary measurement function when flow measurement is abnormal, and a function of interrupting and continuing measurement when the automatic measurement and control system cannot normally operate due to unexpected conditions during measurement; the flow measurement system uses a client / embedded server mode, the embedded server uses a Linux operating system which is stable and reliable, and remote control function and image transmission can be realized without the aid of third-party control software; the system automatically generates accurate and reliable reports. After the flow measurement is completed, the system automatically generates data reports, the report format fully meets the requirements of hydrological specifications, and can be directly used for compilation. Before the report is generated, if there is any objection to the measurement point, any measurement point can be re-measured at any time, once the report is generated, the data cannot be modified to prevent human tampering with the original data and ensure the authenticity and reliability of the data measurement.

[0066] The full-automatic electromechanical integrated flow measurement system takes a full-automatic measurement and control software system as the core, and through technical upgrading of the hardware system, realizes on-site measurement, calculation, arrangement and analysis, automatic acquisition of water level, starting point distance, water depth, flow rate and other data signals, automatic calculation of water surface width, cross-section flow and other hydrological elements, and output of flow result data compatible with the specification compilation program. Under the premise of meeting the requirements of the flow measurement specification, the measurement duration is shortened, the labor intensity is reduced, the human operation error and the hardware failure rate are reduced, the stability and reliability of the measurement are improved, and the reform of the measurement and reporting mode and the modernization of hydrology are promoted.

[0067] Referring to Figure 8 , the principle of radar flow measurement technology is based on the Doppler effect. This effect is named after Austrian physicist Christian Johann Doppler in recognition of his contribution in this field. In the field of acoustics, when there is relative motion between the sound source and the receiving body (including the probe and the reflecting body), the frequency of the echo will change, and this frequency change is called frequency shift, i.e. Doppler effect. When the radar current meter moves at a relative speed V with the water body, the frequency of the electromagnetic wave received by the radar current meter is different from the frequency of the electromagnetic wave emitted by itself, and this frequency difference is called Doppler shift. By analyzing the relationship between the frequency shift and the speed V, the flow rate of the fluid surface can be calculated.

[0068] Referring to Figure 9The radar flowmeter integrates a radar water level meter and a radar flow velocity meter to measure the water surface distance and flow velocity. The radar water level meter has an antenna beam angle of 11x11°, and the radar antenna angle is 14x32°. When the radar water level meter irradiates the water surface, the irradiation area is similar to a circle. When the radar flow velocity meter irradiates the water surface, the irradiation area is similar to an elliptical area.

[0069] Referring to Figure 10 The measured surface flow velocity is converted into cross-section average flow velocity according to the built-in water conservancy model of the radar flowmeter through preset cross-section parameters. According to the measured liquid level, the radar flowmeter automatically calculates the cross-section area in combination with the cross-section geometric parameters, and then obtains the flow according to the flow velocity-area method formula. Finally, the liquid level, cross-section average flow velocity and flow are transmitted to the data management platform.

[0070] The radar flowmeter is a non-contact flow velocity measuring device, and its remarkable feature is that it can realize remote fluid measurement without direct contact with the water body. When measuring the flow velocity, the device is not disturbed by factors such as water surface conditions, floating objects in the water, water quality and flow state. Under the conditions of high flood and high sediment, the radar flowmeter will replace contact-type flow measuring devices such as acoustic time difference method to monitor the flow of water in channels and rivers.

[0071] However, the radar flowmeter mainly measures the flow velocity of the water surface, and its performance in low-speed measurement is not ideal. The low-speed end of the measurement range is relatively high, usually above 0.3 m / s. In the case of extremely smooth water surface, even if the flow velocity is high, the instrument may not work normally due to the lack of sufficient reflection signals. In addition, the movement speed of waves and floating objects is not consistent with the flow velocity of the water surface. This difference will change due to different water flow conditions, floating object characteristics and wind speed and direction, resulting in measurement errors that cannot be ignored. In addition to moving with the water flow, waves and floating objects also have their own movement, which will also introduce additional measurement errors.

[0072] Referring to Figure 11 The basic principle is to use a pair of ultrasonic transducers. Ultrasonic waves propagate at a uniform speed in liquids or solids, which is set as c, and the fluid velocity is V. Both A and B are used to emit and receive ultrasonic probes. The length of the AB connecting line (sound channel) is L, and the angle between it and the flow direction is θ.

[0073] The ultrasonic wave is emitted by the A probe and received by the B probe, and the propagation time T up The ultrasonic wave is emitted by the B probe and received by the A probe, and the propagation time T down .

[0074]

[0075] θ: sound channel angle, the angle between the sound channel and the flow channel axis; L: length of sound channel, actual path of ultrasonic signal propagation.

[0076] The main equipment of the acoustic full-section time-difference method flow online monitoring system is the acoustic full-section time-difference method flowmeter, which comprises a device host, a slave, a matrix type sonar transducer (frequency 200 kHz, 90 kHz, 28 kHz), a high-precision timing device, wireless transmission, and a flow totalizer. Other devices further comprise a water level gauge, a device installation kit, a power supply system (both mains and solar power supply are available), a device special support, and the like.

[0077] The measurement is realized through the interactive work of the two sets of equipment installed on the workstations on both sides of the river. The installation orientation is usually at an angle of 45 degrees to the direction of the river, and the double machines are used to alternately emit modulated ultrasonic signals, and the flow velocity of the full section of the river is determined according to the time difference required by the double machines to receive the signals of the other party.

[0078] After the sonar signal is emitted from the host, within the range of 45-degree angle, the acoustic direct wave and the multi-path wave reverberation are mixed, and the complete signal is obtained by the slave. After reciprocity, the slave sound wave passes through the same channel, and the acoustic signal received by the host can basically reflect the flow velocity field properties of the transducer elevation water layer. Through the representative model of the water layer flow velocity, the flow velocity of a certain water depth can be calculated. Generally, one layer of transducer can represent about 4 meters of water depth (slightly changed according to the cross-section width and the regularity degree of the cross-section).

[0079] The flow velocity algorithm mainly uses the water level area method to calculate, and the calculation of the virtual vertical flow velocity is carried out according to the distribution law of the water flow velocity along the cross section, the cross-section characteristics, the water level, the virtual flat-bottom channel coefficient, the installation height of the transducer, and the measured flow velocity of the time-difference method instrument. Then, the cross-section flow is calculated according to the flow velocity meter method.

[0080] The measured flow velocities of the multiple sound channels V i (i=1, 2, …, k), k is the number of sound channels, are combined by using the mathematical function relationship to obtain the estimated value of the average flow velocity of the channel / river , multiplied by the flow area A, to obtain the volume flow qv. qv= A ; The characteristics are as follows: The device is installed on both sides of the channel, and the installation is convenient without water, but relatively difficult with water. Post-maintenance: the probe may be covered by sundries, and needs to be maintained regularly. The measurable cross-section range is large; wireless communication and high-precision timing synchronization system are adopted; the system has strong anti-sand content capacity; it is suitable for cross-sections in turbulent state; a multi-layer system can be used to measure the stratified flow velocity and calculate the total flow of the cross-section.

[0081] The disadvantages are that unstable cross-section should be avoided; certain water depth is required; the sensor is at risk of being damaged by garbage; the acoustic signal is affected by some factors: suspended solids, weeds, bubbles, temperature and salinity, etc.

[0082] ADCP flow test method The acoustic wave has a unique effect that when the acoustic wave approaches an object, the frequency experienced by the object is higher than the frequency of the transmitted wave, and when the acoustic wave moves away from the object, the frequency experienced by the object is lower than the frequency of the transmitted wave, which is the famous acoustic Doppler shift effect. ADCP measures water flow velocity by using this principle. ADCP transmits short pulses of acoustic waves of fixed frequency into the water. These pulses encounter scattering bodies (plankton, silt, etc.) in the water and backscatter. The ADCP receives the backscatter signal and processes the Doppler shift to obtain the flow velocity and measure the relative motion in the water body, including the motion speed of the water body relative to the instrument and the speed of the instrument in the water body. The principle can be represented by the following formula: , where is the Doppler shift (HZ); F is the transmitted wave frequency (HZ); V is the water flow velocity along the acoustic beam direction (m / s); C is the propagation speed of the acoustic wave in water (m / s).

[0083] ADCP continuously transmits acoustic waves into the water body and receives acoustic waves. In this way, all points on the vertical line are measured. Combined with the water depth measured by the side depth device, the unit flow of the vertical line is obtained. When ADCP measures from the beginning of the cross-section to the end of the cross-section, the flow of the entire cross-section is measured.

[0084] From the formula of the measurement principle of ADCP, it can be seen that the influencing factors of flow velocity V include: , acoustic Doppler shift, Fs, transmitted frequency, c, propagation speed of acoustic wave in water, and propagation speed of acoustic wave in water is usually a certain value, but the temperature and salinity of the water body have a certain influence on this value; in the influence of Fd, the frequency of the transmitted wave is fixed, and the only factor affecting the flow velocity V is the receiving frequency. Therefore, from the measurement principle, the receiving device of the acoustic wave in the ADCP instrument is the key factor affecting the measurement accuracy of the flow velocity, and the material and manufacturing process of the equipment determine the measurement accuracy of the equipment.

[0085] The application of ADCP in channels (especially large flow water channels) is relatively rare. The main difficulty is that large flow water channels are often accompanied by large flow velocity, and relying solely on test personnel at both ends of the channel can easily cause the ship to tilt or even capsize, making on-site testing difficult and posing a greater safety risk. The use effect is not good in the presence of large sediment content and moving bottom.

Claims

1. An intelligent hydrological monitoring system based on Internet of Things, characterized in that: It 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. The flow measurement control platform communicates with the PLC controller and the flow measurement system via 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 meet the action requirements of the flow measurement system during flow measurement. The flow measurement system is used to acquire hydrological monitoring data and upload it to the flow measurement control platform.

2. The IoT based smart hydrological monitoring system as claimed in claim 1, wherein: 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.

3. The IoT based smart hydrological monitoring system as claimed in claim 2, wherein: 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.

4. The IoT based smart hydrological monitoring system as claimed in claim 1, wherein: 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.

5. 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.

6. The IoT-based intelligent hydrological monitoring system according to claim 1, characterized in that: The network communication module consists of 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, as well as between the mechanical system and the flow measurement control platform. Internal network data transmission is accomplished via microwave communication, while external network data transmission is achieved via the Internet or a dedicated network.

7. The IoT-based intelligent hydrological monitoring system according to claim 5, 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.

8. The IoT-based intelligent hydrological monitoring system according to claim 7, 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.

9. The IoT-based intelligent hydrological monitoring system according to claim 7, characterized in that: The parameter settings include setting the water depth measurement range corresponding to the 1-5 point method on each vertical line.

10. The IoT-based intelligent hydrological monitoring system according to claim 7, 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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