A method for calculating flow rate from surface velocity in edge devices

Abstract

This invention belongs to the field of hydrological measurement technology and provides a method for calculating flow rate using surface velocity in edge computing devices. The method includes the following steps: S1, importing and storing a water level stratification velocity conversion parameter table into the edge computing device; S2, collecting real-time water level and real-time surface velocity, and calculating the cross-sectional water-passing area; S3, querying the water level stratification velocity conversion parameter table to obtain characteristic water levels, and reading the corresponding vertical lines and velocity conversion coefficients; S4, calculating the average velocity of the corresponding vertical lines based on the velocity conversion coefficients and real-time surface velocity, and calculating the average velocity of the river channel; S5, calculating the real-time flow rate of the river channel based on the average flow rate and the cross-sectional water-passing area. This invention is applicable to low-power edge computing devices in the field and can improve the accuracy of flow measurement in emergency river conditions.

Description

Technical Field

[0001] This invention belongs to the field of hydrological measurement technology, specifically relating to a method for calculating flow rate from surface velocity in edge devices, applicable to scenarios where automatic field measurement equipment continuously monitors flow velocity in unattended situations. Background Technology

[0002] Flow measurement of natural rivers is a very important task in hydrological surveying. However, in the measurement of river flow, the surface velocity of a cross section is different from that of the middle and lower layers. To achieve a more accurate flow measurement, it is necessary to measure the velocity at different water depths of the cross section before calculating the overall river flow. When the flood flow is fast and the water carries a lot of silt or debris, the velocity sensor must be inserted into the water to measure the underwater velocity. The debris in the water can easily damage the velocity sensor, and the measurement efficiency is low. This method is not suitable for flood flow measurement in emergency situations, nor is it suitable for continuous monitoring of river sections with large changes in flood flow when there is no one on duty. Summary of the Invention

[0003] This invention aims to address the technical problems existing in the prior art by providing a method for calculating flow rate from surface velocity in edge devices. This method is suitable for low-power edge computing devices in the field and is applicable to the accurate measurement of river flow in field environments with high sediment content, many debris carried in the water, and no human intervention. It can effectively improve the accuracy of flood flow measurement in emergency situations.

[0004] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0005] A method for calculating flow rate using surface velocity in edge devices includes the following steps:

[0006] S1. Draw a table of water level stratification flow velocity conversion parameters under historical characteristic water levels, import the table of water level stratification flow velocity conversion parameters into the edge computing device and store it as a parameter for flow velocity calculation.

[0007] S2. Collect the real-time water level and real-time surface velocity of the river channel. Based on the intersection line between the real-time water level and the cross section of the river channel, obtain the water-passing area of ​​the cross section of the river channel and calculate the water-passing area of ​​the cross section.

[0008] S3. Input the collected real-time water level into the edge computing device, query the water level stratification flow velocity conversion parameter table in the edge computing device, obtain the characteristic water level that matches the real-time water level, and read the corresponding vertical line and flow velocity conversion coefficient based on the characteristic water level.

[0009] S4. Calculate the average flow velocity of the corresponding vertical line using the edge computing device based on the velocity conversion factor and the real-time surface velocity, and then calculate the average flow velocity of the river channel.

[0010] S5. Calculate the real-time flow rate of the river based on the average flow velocity and cross-sectional water area of ​​the river.

[0011] Optionally, in step S1, the water level stratification velocity conversion parameter table includes multiple clusters of characteristic water levels, each cluster of characteristic water levels includes multiple clusters of vertical lines, and each cluster of vertical lines includes multiple velocity conversion coefficients.

[0012] Optionally, a water level stratification velocity conversion parameter table is generated using a parent-child table method. The parent table records the correspondence between each cluster of characteristic water levels and the cluster number of multiple velocity conversion coefficients. The child table records each cluster of vertical lines and the data clusters formed by the corresponding multiple velocity conversion coefficients. Each cluster of characteristic water levels contains multiple clusters of vertical lines, and each cluster of vertical lines contains several velocity conversion coefficients. Each cluster of characteristic water levels corresponds to a characteristic water level value range.

[0013] Optionally, the characteristic water level value is based on the water level measured at different water depths at the installation section of the flow meter.

[0014] Alternatively, characteristic water levels can be collected using one of the following methods: radar sensor, contact sensor, or image recognition method.

[0015] Optionally, for a certain characteristic water level, different water depths are arranged in an arithmetic sequence, multiple clusters of vertical lines are measured for different water depths, and multiple velocity conversion coefficients are measured for each cluster of vertical lines.

[0016] Optionally, surface velocity data and depth velocity data under historical characteristic water levels can be collected using one or more of Doppler current profilers, rotor current meters, and rotary cup current meters. The surface velocity data and depth velocity data can be combined to calculate the velocity conversion factor and draw a table of velocity conversion parameters for water level stratification.

[0017] Optionally, in step S2, the real-time water level is collected by a water level gauge and the real-time surface velocity is collected by a flow meter.

[0018] Optionally, in step S3, when performing a query, the collected real-time water level is matched with the characteristic water level, and the matching method is one of the following: the split-half method, the downward compatibility method, and the upward compatibility method.

[0019] Optionally, in step S4, the formula for calculating the average flow velocity of the river channel is as follows:

[0020] S=(S 垂线1 +S 垂线2 +S 垂线3 +...+S 垂线N ) / n,

[0021] Where S is the average flow velocity of the river channel, S 垂线1 To S 垂线n is the average flow velocity from vertical line 1 to vertical line N, and n is the number of vertical lines;

[0022] The formula for calculating the average velocity along a vertical line is as follows:

[0023] S 垂线i =(S 表 ×coefficient1+S 表 ×coefficient2+...+S 表 × coefficient M ) / m,

[0024] Among them, S 垂线i Let S be the average flow velocity along vertical line i. 表 The real-time surface velocity corresponding to vertical line i, with coefficients 1 to 1. M is the velocity conversion factor corresponding to vertical line i, which is obtained from the comparative calibration results, and m is the number of velocity conversion factors for vertical line i.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] (1) This invention is applicable to unattended field environments and scenarios where low-power edge computing devices are used to continuously monitor flow. It is suitable for continuous and accurate measurement of river flow in unattended field environments with high sediment content, a lot of debris in the water, and no human presence. It can effectively improve the accuracy of flood flow measurement in emergency river conditions and can be used for rapid and accurate flow measurement when hydrological stations have no public network signal or communication is interrupted. It can provide more accurate data for flood control decision-making.

[0027] (2) This invention obtains the average flow velocity of the river channel by automatically matching the flow velocity conversion coefficient on each vertical line in real time water level, and then calculates the real-time flow of the river channel, thereby improving the accuracy of edge device calculation.

[0028] (3) This invention avoids the problem of excessive calculation error caused by using only surface velocity and a single conversion factor to calculate flow rate, and improves the accuracy of calculating flow rate using surface velocity.

[0029] (4) This invention is applicable to field areas with poor or interrupted communication, has stronger environmental adaptability, provides strong support for improving the flood response capabilities of hydrological stations, and is also an effective method for improving the accuracy of water resource monitoring in terms of water resource measurement. Attached Figure Description

[0030] Figure 1 This is a flowchart of a surface flow velocity calculation method for edge devices according to an embodiment of the present invention;

[0031] Figure 2 This is a technical roadmap for a surface flow velocity calculation method for edge devices according to an embodiment of the present invention;

[0032] Figure 3 This is a table of parameters for calculating the stratified flow velocity at water levels, as described in this embodiment of the invention.

[0033] Figure 4 This is a roadmap for computational flow rate in an embodiment of the present invention. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] Combination Figures 1-4 As shown, this embodiment of the invention provides a method for calculating the surface velocity of an edge device, comprising the following steps:

[0037] S1. Draw a table of water level stratification flow velocity conversion parameters under historical characteristic water levels, import the table of water level stratification flow velocity conversion parameters into the edge computing device and store it as a parameter for flow velocity calculation.

[0038] S2. Collect the real-time water level and real-time surface velocity of the river channel. Based on the intersection line between the real-time water level and the cross section of the river channel, obtain the water-passing area of ​​the cross section of the river channel and calculate the water-passing area of ​​the cross section.

[0039] S3. Input the collected real-time water level into the edge computing device, query the water level stratification flow velocity conversion parameter table in the edge computing device, obtain the characteristic water level that matches the real-time water level, and read the corresponding vertical line and flow velocity conversion coefficient based on the characteristic water level.

[0040] S4. Calculate the average flow velocity of the corresponding vertical line using the edge computing device based on the velocity conversion factor and the real-time surface velocity, and then calculate the average flow velocity of the river channel.

[0041] S5. Calculate the real-time flow rate of the river based on the average flow velocity and cross-sectional water area of ​​the river.

[0042] The above methods and steps are applicable to environments where low-power edge computing devices in the field continuously perform traffic monitoring and calculations.

[0043] Furthermore, in step S1, the water level stratification velocity conversion parameter table includes multiple characteristic water levels, each characteristic water level includes multiple clusters of vertical lines, and each cluster of vertical lines includes multiple velocity conversion coefficients.

[0044] Example 2

[0045] Combination Figures 1-4 As shown, this embodiment of the invention provides a method for calculating the surface velocity of an edge device, comprising the following steps:

[0046] S1. Draw a table of water level stratification flow velocity conversion parameters under historical characteristic water levels, import the table of water level stratification flow velocity conversion parameters into the edge computing device and store it as a parameter for flow velocity calculation.

[0047] S2. Collect the real-time water level and real-time surface velocity of the river channel. Based on the intersection line between the real-time water level and the cross section of the river channel, obtain the water-passing area of ​​the cross section of the river channel and calculate the water-passing area of ​​the cross section.

[0048] S3. Input the collected real-time water level into the edge computing device, query the water level stratification flow velocity conversion parameter table in the edge computing device, obtain the characteristic water level that matches the real-time water level, and read the corresponding vertical line and flow velocity conversion coefficient based on the characteristic water level.

[0049] S4. Calculate the average flow velocity of the corresponding vertical line using the edge computing device based on the velocity conversion factor and the real-time surface velocity, and then calculate the average flow velocity of the river channel.

[0050] S5. Calculate the real-time flow rate of the river based on the average flow velocity and cross-sectional water area of ​​the river.

[0051] Furthermore, in step S1, the water level stratification velocity conversion parameter table includes multiple characteristic water levels, each characteristic water level includes multiple clusters of vertical lines, and each cluster of vertical lines includes multiple velocity conversion coefficients.

[0052] Specifically, in accordance with the requirements of the "Specification for River Flow Measurement" (GB50179-2015), sufficient vertical velocity data are measured at characteristic water levels to form conversion parameters. The conversion parameters are the conversion coefficients between the flow velocity at the measuring point and the surface velocity at different vertical depths.

[0053] Based on this, in this embodiment, a water level stratification velocity conversion parameter table is generated by a parent-child table method. The parent table records the correspondence between each cluster of characteristic water levels and the cluster number of multiple velocity conversion coefficients. The child table records the data clusters formed by each cluster of vertical lines and the corresponding multiple velocity conversion coefficients. Each characteristic water level contains multiple clusters of vertical lines, and each cluster of vertical lines contains several velocity conversion coefficients. Each cluster of characteristic water levels corresponds to a characteristic water level value range.

[0054] Specifically, obtain the characteristic water level range that matches the current water level, read the corresponding vertical line and decomposition coefficient data based on the characteristic water level range, and read at least one vertical line, with each vertical line containing at least one conversion coefficient; then convert the multiple velocity conversion coefficients on each vertical line to the surface velocity to obtain the corresponding velocity value, and then perform the average velocity conversion to finally complete the flow rate calculation.

[0055] As a preferred method, the characteristic water level range is obtained based on the flow velocity range measured by the flow meter at different cross-sections at different water depths;

[0056] As a preferred method, water level height can be collected using one of the following: radar sensors, contact sensors, or image recognition methods; alternatively, water level data can be obtained through manual observation and data collection.

[0057] As a preferred method, for a certain characteristic water level, different water depths are arranged in an arithmetic sequence, multiple clusters of vertical lines are measured for different water depths, and multiple flow velocity conversion coefficients are measured for each cluster of vertical lines.

[0058] Specifically, the characteristic water level is determined based on the shape of the instrument's installation cross-section. In natural river channels, the determination of the characteristic water level is related to changes in the cross-sectional shape. At points of abrupt changes in shape, it is advisable to add a characteristic water level and measure a set of vertical lines and corresponding conversion factors. In channels, different water depths can be determined using an arithmetic progression, and then a set of vertical lines and corresponding conversion factors can be measured for each water depth. The selection of the characteristic water level should consider its representativeness; it is advisable to determine a characteristic water level for a given water depth where the number of vertical lines and conversion factors is the same, and where the changes are relatively small. Furthermore, it is important to note that two closely spaced characteristic water levels should have different numbers of vertical lines or conversion factors to avoid data redundancy that wastes storage space and computational efficiency.

[0059] As a preferred method, surface velocity and depth velocity data at historical characteristic water levels are collected using one or more of Doppler current profilers (ADCP), rotor current meters, and vortex cup current meters. The surface velocity data and depth velocity data are then combined to calculate the velocity conversion factor, and a table of velocity conversion parameters for water level stratification is drawn. Specifically, rotor current meters and vortex cup current meters require manual operation, but other contactless sensors can also be used for data collection. In addition, calculating the velocity conversion factor from surface velocity data and depth velocity data is existing technology and will not be elaborated on here.

[0060] Example 3

[0061] Combination Figures 1-4 As shown, this embodiment of the invention provides a method for calculating the surface velocity of an edge device, comprising the following steps:

[0062] S1. Draw a table of water level stratification flow velocity conversion parameters under historical characteristic water levels, import the table of water level stratification flow velocity conversion parameters into the edge computing device and store it as a parameter for flow velocity calculation.

[0063] S2. Collect the real-time water level and real-time surface velocity of the river channel. Based on the intersection line between the real-time water level and the cross section of the river channel, obtain the water-passing area of ​​the cross section of the river channel and calculate the water-passing area of ​​the cross section.

[0064] S3. Input the collected real-time water level into the edge computing device, query the water level stratification flow velocity conversion parameter table in the edge computing device, obtain the characteristic water level that matches the real-time water level, and read the corresponding vertical line and flow velocity conversion coefficient based on the characteristic water level.

[0065] S4. Calculate the average flow velocity of the corresponding vertical line using the edge computing device based on the velocity conversion factor and the real-time surface velocity, and then calculate the average flow velocity of the river channel.

[0066] S5. Calculate the real-time flow rate of the river based on the average flow velocity and cross-sectional water area of ​​the river.

[0067] Based on this, in this embodiment, in step S2, the real-time water level is collected by a water level gauge and the real-time surface velocity is collected by a flow meter.

[0068] As a preferred approach, in step S3, when performing a query, the collected real-time water level is matched with the characteristic water level, and the matching method adopts one of the following: the split-half method, the downward compatibility method, and the upward compatibility method.

[0069] Specifically, the halving method involves taking the average of a certain characteristic water level with its two adjacent characteristic water levels. The two numbers obtained are the water level range represented by the current characteristic water level. When the current water level falls within this range, the vertical coefficient cluster of the current characteristic water level is taken as the calculation parameter. This method is suitable for rivers or channels with regular cross-sectional shapes.

[0070] The downward compatibility method uses the current characteristic water level and the adjacent lower characteristic water level as the interval. When the current water level falls within this interval, the vertical coefficient cluster of the current characteristic water level is taken as the calculation parameter.

[0071] The upward compatibility method, in contrast to the downward compatibility method, uses the current characteristic water level and the adjacent higher characteristic water level as an interval. When the current water level falls within this interval, the vertical coefficient cluster of the current characteristic water level is used as the calculation parameter. Both the downward and upward compatibility methods are suitable for natural river channels with irregular cross-sectional shapes.

[0072] Example 4

[0073] Combination Figures 1-4As shown, this embodiment of the invention provides a method for calculating the surface velocity of an edge device, comprising the following steps:

[0074] S1. Draw a table of water level stratification flow velocity conversion parameters under historical characteristic water levels, import the table of water level stratification flow velocity conversion parameters into the edge computing device and store it as a parameter for flow velocity calculation.

[0075] S2. Collect the real-time water level and real-time surface velocity of the river channel. Based on the intersection line between the real-time water level and the cross section of the river channel, obtain the water-passing area of ​​the cross section of the river channel and calculate the water-passing area of ​​the cross section.

[0076] S3. Input the collected real-time water level into the edge computing device, query the water level stratification flow velocity conversion parameter table in the edge computing device, obtain the characteristic water level that matches the real-time water level, and read the corresponding vertical line and flow velocity conversion coefficient based on the characteristic water level.

[0077] S4. Calculate the average flow velocity of the corresponding vertical line using the edge computing device based on the velocity conversion factor and the real-time surface velocity, and then calculate the average flow velocity of the river channel.

[0078] S5. Calculate the real-time flow rate of the river based on the average flow velocity and cross-sectional water area of ​​the river.

[0079] Based on this, in this embodiment, the formula for calculating the average flow velocity of the river channel in step S4 is as follows:

[0080] S=(S 垂线1 +S 垂线2 +S 垂线3 +...+S 垂线N ) / n,

[0081] Where S is the average flow velocity of the river channel, S 垂线1 To S 垂线n is the average flow velocity from vertical line 1 to vertical line N, and n is the number of vertical lines;

[0082] The formula for calculating the average velocity along a vertical line is as follows:

[0083] S 垂线i =(S 表 ×coefficient1+S 表 ×coefficient2+...+S 表 × coefficient M ) / m,

[0084] Among them, S 垂线i Let S be the average flow velocity along vertical line i. 表 The real-time surface velocity corresponding to vertical line i, with coefficients 1 to 1. Mis the velocity conversion factor corresponding to vertical line i, which is obtained from the comparative measurement calibration, and m is the number of velocity conversion factors for vertical line i;

[0085] Specifically, the comparative calibration is the result of the calibration work of hydrological instruments.

[0086] The above description is merely an embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A surface flow rate calculation flow method for edge devices, characterized by, The method comprises the following steps: S1, draw a water level stratified flow rate conversion parameter table under a historical characteristic water level, import the water level stratified flow rate conversion parameter table into an edge computing device and store it as a parameter for flow rate calculation; S2, collect real-time water level and real-time surface flow rate of the river channel, obtain the water passing area of the river channel cross section according to the intersection line of the real-time water level and the river channel cross section, and calculate the water passing area of the cross section; S3, input the collected real-time water level into the edge computing device, query the water level stratified flow rate conversion parameter table in the edge computing device, obtain the characteristic water level matched with the real-time water level, and read the corresponding vertical line and flow rate conversion coefficient according to the characteristic water level; S4, calculate the average flow rate of the corresponding vertical line according to the flow rate conversion coefficient on the corresponding vertical line and the real-time surface flow rate through the edge computing device, and then calculate the average flow rate of the river channel; S5, calculate the real-time flow rate of the river channel according to the average flow rate of the river channel and the water passing area of the cross section. In step S1, the water level stratified flow rate conversion parameter table comprises a plurality of characteristic water levels, each characteristic water level comprises a plurality of vertical lines, and each cluster of vertical lines comprises a plurality of flow rate conversion coefficients.

2. The surface flow rate computational flow method for edge devices of claim 1, wherein, The water level stratified flow rate conversion parameter table is generated by a parent-child table method, the parent table records the corresponding relationship between each cluster of characteristic water levels and the cluster serial numbers of a plurality of flow rate conversion coefficients, and the child table records the data cluster formed by each cluster of vertical lines and a plurality of corresponding flow rate conversion coefficients.

3. The surface flow rate computational flow method for edge devices of claim 2, wherein, The characteristic water level value range is obtained according to the flow rate range of the current meter at different cross sections and different water depths.

4. The surface flow rate computational flow method for edge devices of claim 3, wherein, The water surface height is collected by one of a radar sensor, a contact sensor and an image recognition method.

5. The surface flow rate computational flow method for edge devices of claim 2, wherein, For a certain characteristic water level, different water depths are arranged in an arithmetic sequence, a plurality of clusters of vertical lines are measured for different water depths, and a plurality of flow rate conversion coefficients corresponding to each cluster of vertical lines are measured.

6. The surface flow rate computational flow method for edge devices of claim 5, wherein, The surface flow rate data and depth flow rate data under the historical characteristic water level are collected by one or more of a Doppler flow rate profiler, a rotor current meter and a rotating cup current meter, the surface flow rate data and depth flow rate data are collected to calculate the flow rate conversion coefficient, and the water level stratified flow rate conversion parameter table is drawn.

7. The surface flow rate computational flow method for edge devices of claim 1, wherein, In step S2, the real-time water level is collected by a water level gauge, and the real-time surface flow rate is collected by a current meter.

8. The surface flow rate computational flow method for edge devices of claim 1, wherein, In step S3, when querying, the collected real-time water level is matched with the characteristic water level, and the matching method adopts one of a bisection method, a downward compatibility method and an upward compatibility method.

9. The surface flow rate computational flow method for edge devices of claim 1, wherein, In step S4, the average flow rate of the river channel is calculated according to the following formula: ， wherein, is the average flow velocity of the river course, to is the average flow velocity of the perpendicular line 1 to the perpendicular line to is the number of perpendicular lines; The average flow rate of the vertical line is calculated according to the following formula: ， wherein, is the average flow velocity of the vertical line is the corresponding real-time surface flow velocity of the vertical line is the corresponding flow velocity conversion coefficient of the vertical line is the corresponding first flow velocity conversion coefficient of the vertical line is the corresponding second flow velocity conversion coefficient of the vertical line is the number of flow velocity conversion coefficients of the vertical line ​​​​​​​​

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