A multi-channel river flow calculation method based on acoustic time difference method

Abstract

The application relates to the technical field of river hydrological testing, in particular to a multi-channel river flow calculation method based on an acoustic time difference method, which comprises the following steps: calculating the average flow velocity of the near-river-bottom partial area according to the measured flow velocity of the near-river-bottom channel and a river bottom shape coefficient, multiplying the average flow velocity by the near-river-bottom partial area to obtain the near-river-bottom partial area flow; determining the average flow velocity of the inter-channel partial area according to the measured flow velocities of two adjacent channels, multiplying the average flow velocity by the inter-channel partial area determined according to the elevations of the two adjacent channels to obtain the inter-channel partial area flow; calculating the surface flow velocity according to a logarithmic flow velocity formula and the measured flow velocity of the near-surface channel, then calculating the average flow velocity of the near-surface partial area, multiplying the average flow velocity by the near-surface partial area to obtain the near-surface partial area flow; and adding the near-river-bottom partial area flow, the inter-channel partial area flow and the near-surface partial area flow to obtain the final river cross-section flow. The method effectively improves the accuracy of river flow calculation.

Description

Technical Field

[0001] The embodiments of this application relate to the field of river hydrological measurement technology, and in particular to a multi-channel river flow calculation method based on acoustic time difference method. Background Technology

[0002] Acoustic time-of-flight flow measurement technology, with its advantages of simplicity, reliability, real-time capability, and online operation, has been widely applied in real-time online flow monitoring and is currently a relatively mature technical solution for automatic flow reporting. During the propagation of ultrasonic waves from one bank to the other in a river channel, the average velocity across the cross-section of the river can be obtained by calculating the difference between the downstream and upstream propagation times at a given moment and dividing it by the propagation path. Multiplying the velocity by the area yields the flow rate.

[0003] Multichannel river flow calculation based on the acoustic time-of-flight method refers to measuring the average flow velocity of water passing through the horizontal line of the equipment elevation using ultrasonic devices (also known as sound channels) deployed at different elevations on both banks of the river. The river flow is then calculated based on the average flow velocity of the sound channels at different elevations. A commonly used method is the area velocity method, which involves obtaining the average flow velocity of a portion of the river cross-section, multiplying it by the area to obtain the flow component, and summing the flow components of the portions to obtain the river cross-section flow.

[0004] Acoustic time-of-flight (TOF) flow measurement technology has been promoted in China since the late 20th century, initially applied to artificial channel flow measurement scenarios. After years of continuous upgrades and innovations, it has been gradually applied to river flow measurement scenarios. However, to date, no domestic standards or specifications for TOF river flow measurement have been established; currently, the international standard ISO 6416:2017-10 is still being followed. In general, the application of acoustic TOF flow measurement technology to river flow measurement production still faces the following three problems.

[0005] First, there is the issue of calculation error in the cross-sectional area. The method for calculating the cross-sectional area specified in ISO 6416:2017-10 uses the cross-sectional width of the channel depth combined with the trapezoidal area formula. In channels and natural rivers where the conditions of the trapezoidal cross-sectional formula are not met, the calculated cross-sectional area has a relatively large error, which in turn leads to a relatively large error in flow measurement.

[0006] Second, there is the issue of error in the average flow velocity across the near-bottom area. ISO 6416:2017-10 specifies that the flow velocity measured near the bottom of the channel should be multiplied by a given bottom coefficient. The riverbed coefficient is the average flow velocity over the area near the riverbed. The value ranges from 0.7 to 0.9, but no basis is given for this value. Riverbed coefficient The arbitrariness of the flow rate results in an error in the average flow velocity of the near-bottom area, which in turn leads to a large error in the flow measurement results, especially in natural rivers where this error is even greater.

[0007] Third, there is the error in the average flow velocity of the area near the water surface. ISO 6416:2017-10 uses the flow velocity measurements from the two channels closest to the water surface, which are linearly extrapolated before being multiplied by a water surface adjustment factor. Thus, the surface velocity of the water can be deduced. Then, the average velocity of the near-water surface area is calculated using the surface velocity and the velocity measurements of the near-water channel. However, this method uses a linear extrapolation value that is too large, and the water surface adjustment coefficient... There is also arbitrariness, which leads to a large error in the calculated average flow velocity of the near-water surface area. As the distance between the water surface and the near-water surface sound channel increases, the error in the water surface flow velocity will far exceed the requirements of the flow measurement specifications.

[0008] Some research teams have used interpolation methods based on measured water level area curves to replace the trapezoidal area formula, which has effectively solved the problem of calculation error in cross-sectional area. However, for areas near the riverbed and near the water surface, the method of calibration using measured hydrological data requires determining the riverbed coefficient. and water surface velocity adjustment coefficient Finding the correct value requires significant manpower and resources, but the improvement in accuracy is minimal in practical applications. and The coefficients are not single-valued linear. In other words, there are no good solutions to the errors in the average flow velocity near the riverbed and the average flow velocity near the water surface, which leads to low accuracy of the acoustic time difference method in calculating river flow in hydrological surveys. Summary of the Invention

[0009] To address the aforementioned technical issues, embodiments of this application propose a multi-channel river flow calculation method based on acoustic time difference. This method discards the riverbed coefficient and water surface adjustment coefficient, avoids arbitrariness, eliminates errors in water surface velocity caused by linear extrapolation, and saves the manpower, material resources, and time required for calibration coefficients, thereby effectively improving the accuracy of river flow calculation.

[0010] To achieve the above objectives, embodiments of this application propose a multi-channel river flow calculation method based on acoustic time difference method. The method includes the following steps: calculating the average flow velocity of the near-bottom area based on the obtained measured flow velocity values ​​of the near-bottom channel and the riverbed morphology coefficient, and then multiplying it by the near-bottom area to obtain the near-bottom area flow rate; determining the average flow velocity of the inter-channel area based on the obtained measured flow velocity values ​​of two adjacent channels, and then multiplying it by the inter-channel area to obtain the inter-channel area flow rate; wherein, the inter-channel area is determined based on the elevation of the two adjacent channels; calculating the surface flow velocity based on the logarithmic velocity formula and the obtained measured flow velocity values ​​of the near-water surface channel, and then calculating the average flow velocity of the near-water surface area, and then multiplying it by the near-water surface area to obtain the near-water surface area flow rate; and summing the near-bottom area flow rate, the inter-channel area flow rate, and the near-water surface area flow rate to obtain the final river cross-sectional flow rate.

[0011] To achieve the above objectives, embodiments of this application also propose a multi-channel river flow calculation system based on the acoustic time-of-flight method. The system includes: a near-bottom area flow calculation module, used to calculate the average flow velocity of the near-bottom area based on the obtained measured flow velocity values ​​of the near-bottom acoustic channels and the riverbed morphology coefficient, and then multiply it by the near-bottom area to obtain the near-bottom area flow rate; and an inter-channel area flow calculation module, used to determine the average flow velocity of the inter-channel area based on the obtained measured flow velocity values ​​of two adjacent acoustic channels, and then multiply it by the inter-channel area flow rate. The system divides the area to obtain the flow rate of the inter-channel portion, where the inter-channel portion area is determined based on the elevation of two adjacent channels. The near-water surface portion area flow rate calculation module is used to calculate the surface velocity based on the logarithmic velocity formula and the obtained measured velocity values ​​of the near-water surface channel, and then calculate the average velocity of the near-water surface portion area, which is then multiplied by the near-water surface portion area to obtain the near-water surface portion area flow rate. The accumulation module is used to accumulate the near-riverbed portion area flow rate, the inter-channel portion area flow rate, and the near-water surface portion area flow rate to obtain the final river cross-section flow rate.

[0012] To achieve the above objectives, embodiments of this application also propose an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform a multi-channel river flow calculation method based on acoustic time difference as described above.

[0013] To achieve the above objectives, embodiments of this application also propose a computer-readable storage medium storing a computer program that, when executed by a processor, enables a multi-channel river flow calculation method based on acoustic time difference as described above.

[0014] Optionally, before calculating the average flow velocity of the near-bottom area based on the obtained measured flow velocity values ​​of the near-bottom acoustic channel and the riverbed morphology coefficient, the method further includes:

[0015] Sensors were deployed on both banks of the target river channel to set up [the target river channel]. Each channel has a specific elevation and flow velocity, and the measured values ​​of each channel are obtained; among them, the first channel... For the near-bottom sound channel, the first Each channel For near-water surface sound channel, It is an integer greater than 2;

[0016] Based on the cross-sectional map of the target river channel, obtain the area of ​​the near-bottom portion. The area near the riverbed is the cross-sectional area between the near-riverbed sound channel and the riverbed.

[0017] Based on the elevation of the near-riverbed sound channel, the width of the near-riverbed sound channel, and the area of ​​the near-riverbed portion. The starting elevation of the riverbed is calculated, and based on the cross-sectional diagram of the target river channel, the partial cross-sectional area between the starting elevation of the riverbed and the riverbed is obtained. ;

[0018] The starting elevation of the riverbed is expressed by the formula:

[0019] ;

[0020] in, To determine the starting elevation of the riverbed, The elevation of the near-riverbed acoustic channel. The width of the sound channel near the riverbed. This refers to the area near the riverbed.

[0021] Obtain water surface elevation ,Will and The difference between them is taken as the water depth of the target river channel.

[0022] Optionally, based on the obtained measured velocity values ​​of the near-bottom channel and the riverbed morphology coefficient, the average velocity of the near-bottom area is calculated, and then multiplied by the near-bottom area to obtain the near-bottom area flow rate, including:

[0023] Based on the following formula, and Determine the riverbed morphology coefficient:

[0024] ;

[0025] in, This is the riverbed morphology coefficient;

[0026] The average flow velocity near the riverbed is calculated using the following formula, based on the measured flow velocity values ​​of the near-bottom acoustic channel and the riverbed morphology coefficient, and then multiplied by... The flow rate of the near-bottom area is obtained:

[0027] ;

[0028] ;

[0029] in, The flow rate is the area near the riverbed. The average flow velocity is the area near the riverbed. The measured flow velocity is near the bottom of the river channel.

[0030] Optionally, for two adjacent channels and Specifically, the average flow velocity of the inter-channel area is determined based on the measured flow velocity values ​​of two adjacent channels, and then multiplied by the inter-channel area to obtain the inter-channel area flow rate, including:

[0031] Based on the river channel cross-section diagram and sound channel of the target river elevation Harmony Channel elevation ,get and The cross-sectional area of ​​the middle section is used as the vocal tract. With the vocal tract inter-channel area ;

[0032] The average flow velocity of the inter-channel area is determined by the measured flow velocity values ​​of two adjacent channels using the following formula, and then multiplied by the inter-channel area to obtain the inter-channel area flow rate:

[0033] ;

[0034] ;

[0035] in, For the vocal tract The measured flow velocity value, For the vocal tract The measured flow velocity value, For the vocal tract With the vocal tract Average flow velocity across the inter-channel area. For the vocal tract With the vocal tract The flow rate of the inter-channel area.

[0036] Optionally, based on the logarithmic velocity formula and the obtained measured velocity values ​​of the near-surface acoustic channel, the surface velocity is calculated, including:

[0037] Based on Brandt's logarithmic formula with water surface velocity as the base, a logarithmic velocity formula is established, which is expressed as:

[0038] ;

[0039] ;

[0040] in, Let be the line-average velocity at any horizontal line of the target river channel cross-section. For an unknown water surface velocity, For dynamic flow velocity, Kármán's constant, For relative water depth, It is the acceleration due to gravity. For hydraulic gradient, For water depth;

[0041] Channel Measured flow velocity , channel Measured flow velocity Substituting these values ​​into the logarithmic formula for the vertical velocity distribution, we obtain the following about the vocal tract. Regarding the vocal tract Transformation formula:

[0042] ;

[0043] ;

[0044] in, It is the audio channel elevation The relative water depth at that location It is the audio channel elevation The relative water depth and acoustic channel That is, the sound channel near the water surface;

[0045] The following formula is used to describe the relationship between the vocal tract and the vocal tract. Transformation formulas and about the vocal tract Solve the transformation formulas simultaneously to find the surface velocity of the water. :

[0046] .

[0047] Optionally, the average flow velocity of the near-water surface area can be calculated, and then multiplied by the area of ​​the near-water surface to obtain the flow rate of the near-water surface area, including:

[0048] Based on the river channel cross-section diagram and near-water acoustic channel elevation and water surface elevation ,get and The cross-sectional area between the two sections is used as the area near the water surface. ;

[0049] Based on the near-water surface acoustic channel, the following formula is used. Measured flow velocity and water surface velocity Calculate the average flow velocity over the near-water surface area, then multiply by The flow rate of the near-water surface area is obtained as follows:

[0050] ;

[0051] ;

[0052] in, The average flow velocity is the area near the water surface. This refers to the flow rate of the area near the water surface.

[0053] Optionally, the final cross-sectional flow rate of the river channel is obtained by summing the area flow rates near the riverbed, the area flow rates between the channels, and the area flow rates near the water surface, using the following formula:

[0054] ;

[0055] in, The flow rate is the area near the riverbed. The flow rate is the area near the water surface. For the vocal tract With the vocal tract The flow rate of the inter-channel area.

[0056] The embodiments of this application propose a multi-channel river flow calculation method based on acoustic time difference method, which has at least the following advantages compared with traditional calculation methods.

[0057] First, this application uses measured cross-sectional data and the change of cross-section controlled by the arrangement of the sound channels to obtain a partial area, thereby eliminating the calculation error of the partial area between the sound channels as much as possible and effectively improving the calculation accuracy of the river flow.

[0058] Second, this application uses a riverbed morphology coefficient calculated from river cross-section data to replace the artificially given riverbed coefficient in the traditional calculation method, avoiding human arbitrariness and thus avoiding human error in the calculation of the area flow near the riverbed. At the same time, the riverbed morphology coefficient depends on the actual flow measurement cross-section, that is, it is calculated from the measured data. This fundamentally saves a lot of manpower, material resources and time that are consumed in the traditional calculation method of calibrating the riverbed coefficient using hydrological survey data.

[0059] Third, this application uses the logarithmic velocity formula and on-site measured data to calculate the current water surface velocity, replacing the linear extrapolation calculation method in the traditional calculation method. This solves the problem of excessive deviation in water surface velocity in high water sections, eliminates the arbitrary value of the water surface velocity adjustment coefficient, and fundamentally saves a lot of manpower, material resources and time spent on calibration coefficients using hydrological survey data in the traditional calculation method, effectively improving the calculation accuracy of the area flow near the water surface. Attached Figure Description

[0060] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies of this application will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0061] Figure 1 This is a flowchart of a multi-channel river flow calculation method based on acoustic time difference method provided in one embodiment of this application;

[0062] Figure 2 This is a schematic diagram of a four-channel river flow measurement section based on the acoustic time difference method provided in one embodiment of this application.

[0063] Figure 3 This is a schematic diagram of the structure of a multi-channel river flow calculation system based on the acoustic time difference method provided in another embodiment of this application;

[0064] Figure 4 This is a schematic diagram of the structure of an electronic device provided in another embodiment of this application. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. In the various embodiments of this application, many technical details are presented to enable the reader to better understand this application. However, even without these technical details and various variations and modifications based on the following embodiments, the technical solutions claimed in this application can be implemented. The division of the following embodiments is only for convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0066] To address the error issues inherent in traditional river flow calculation methods, one embodiment of this application proposes a multi-channel river flow calculation method based on acoustic time difference, applied to an electronic device. The electronic device can be a terminal or a server. In this embodiment and subsequent embodiments, the electronic device is described using a server as an example. The implementation details of the multi-channel river flow calculation method based on acoustic time difference proposed in this embodiment are described below. The following implementation details are provided for ease of understanding and are not essential for implementing this solution.

[0067] The specific process of the multi-channel river flow calculation method based on acoustic time difference method proposed in this embodiment can be described as follows: Figure 1 As shown, it includes:

[0068] Step 11: Calculate the average flow velocity of the near-bottom area based on the obtained measured flow velocity value of the near-bottom channel and the riverbed morphology coefficient, and then multiply it by the area of ​​the near-bottom area to obtain the flow rate of the near-bottom area.

[0069] In its specific implementation, the river flow calculation method proposed in this embodiment is divided into three stages: near-bottom calculation, inter-channel calculation, and near-surface calculation. The first step is near-bottom calculation. Based on the measured flow velocity values ​​of the near-bottom channel and the riverbed morphology coefficient, the server needs to calculate the average flow velocity of the near-bottom area, and then multiply it by the area of ​​the near-bottom region to obtain the flow rate of the near-bottom region.

[0070] In one example, performing multi-channel river flow calculation based on the acoustic time-of-flight method requires deploying sensors on both banks of the target river and setting up [the target river channel]. One channel The value is an integer greater than 2, which forms a cross-section in the target river channel. After the layout is completed, it is also necessary to obtain the measured values ​​of the elevation and flow velocity of each channel.

[0071] Understandably, the sound channels are set up sequentially from bottom to top, starting from the riverbed and moving upwards. The first sound channel... For the near-bottom sound channel, the first Each channel This is for near-water surface sound channels. The placement of near-riverbed sound channels needs to be as close as possible to the bottom of the target riverbed.

[0072] After completing the audio channel segmentation, the server needs to obtain the area near the riverbed based on the cross-sectional map of the target river channel. The area near the riverbed is the cross-sectional area between the near-riverbed sound channel and the riverbed.

[0073] Next, the server will analyze the elevation, width, and area of ​​the near-bottom acoustic channel. The starting elevation of the riverbed is calculated, and based on the cross-sectional diagram of the target river channel, the partial cross-sectional area between the starting elevation of the riverbed and the riverbed is obtained. .

[0074] The starting elevation of the riverbed is expressed by the formula:

[0075] ;

[0076] in, To determine the starting elevation of the riverbed, The elevation of the near-riverbed acoustic channel. The width of the sound channel near the riverbed. This refers to the area near the riverbed.

[0077] Finally, the server also needs to obtain the water surface elevation. and calculate and The difference between the two values ​​is taken as the water depth of the target river channel. At this point, all preparations are complete, and we can proceed to the subsequent calculation stage.

[0078] In one example, we want to perform a four-channel river flow calculation based on the acoustic time-of-flight method, which means setting up four channels in the target river channel, the first channel... The fourth acoustic channel is located near the riverbed. This is the near-water surface acoustic channel. The measurement cross-section of the four-channel river flow based on the acoustic time-of-flight method is shown below. Figure 2 As shown.

[0079] exist Figure 2 middle, The first sound channel, which is the sound channel near the riverbed, is installed at an elevation of [elevation value missing]. The measured flow velocity value is (Obtained through actual measurement) The width of the cross-section at the location from the left bank to the right bank is . This is the second audio channel, and its installation elevation is... The measured flow velocity value is . This is the third channel, and its installation elevation is... The measured flow velocity value is . This is the fourth sound channel, the one near the water surface, and its installation elevation is... The measured flow velocity value is . Indicates the water surface of the target river channel. Indicates the riverbed of the target river channel. Indicates the starting point of the target riverbed.

[0080] and Each channel The corresponding sensors are deployed on both banks of the target river channel. and Each channel The corresponding sensors are deployed on both banks of the target river channel. and Each channel The corresponding sensors are deployed on both banks of the target river channel. and Each channel The corresponding sensors are deployed on both banks of the target river channel. and These represent the left and right banks of the target river channel, respectively.

[0081] Starting point for riverbed elevation The cross-sectional area between the following portion and the riverbed is: , channel elevation The cross-sectional area of ​​the portion near the riverbed formed by the following is: , channel elevation With the vocal tract elevation The cross-sectional area formed by the two is , channel elevation With the vocal tract elevation The cross-sectional area formed by the two is , channel elevation With the vocal tract elevation The cross-sectional area formed by the two is , channel elevation water surface elevation The cross-sectional area of ​​the near-water surface portion formed by the two is The cross-sectional areas defined above can all be calculated from river cross-sectional data.

[0082] In one example, when the server calculates the average flow velocity of the near-bottom area based on the obtained measured flow velocity values ​​of the near-bottom acoustic channel and the riverbed morphology coefficient, and then multiplies it by the near-bottom area to obtain the near-bottom area flow rate, it first uses the following formula based on... and Determine the riverbed morphology coefficient:

[0083] ;

[0084] in, This represents the riverbed morphology coefficient. This comprehensively reflects the concave and convex characteristics of the riverbed. Under similar conditions, a riverbed with greater concavity and convexity exhibits higher frictional resistance, which has a greater impact on flow velocity and shape coefficient. The value is small. The larger the value, the smaller the impact on the flow rate.

[0085] Next, the average flow velocity of the near-bottom area is calculated using the following formula, based on the measured flow velocity values ​​of the near-bottom acoustic channel and the riverbed morphology coefficient, and then multiplied by... The flow rate of the near-bottom area is obtained:

[0086] ;

[0087] ;

[0088] in, The flow rate is the area near the riverbed. The average flow velocity is the area near the riverbed. The measured flow velocity is near the bottom of the river channel.

[0089] Step 12: Determine the average flow velocity of the inter-channel area based on the measured flow velocity values ​​of the two adjacent channels, and then multiply it by the inter-channel area to obtain the inter-channel area flow rate. The inter-channel area is determined based on the elevation of the two adjacent channels.

[0090] In the specific implementation, after completing the near-bottom calculation, the calculation between the channels can be carried out. The server determines the area between the channels based on the elevation of the two adjacent channels, and determines the average flow velocity of the area between the channels based on the measured flow velocity values ​​of the two adjacent channels. Then, the flow rate of the area between the channels is obtained by multiplying the average flow velocity of the area between the channels by the area between the channels.

[0091] In one example, for two adjacent vocal tracts and In the process of performing inter-channel calculations, it is first necessary to consider the cross-sectional diagram of the target river channel and the audio channels. elevation Harmony Channel elevation ,get and The cross-sectional area of ​​the middle section is used as the vocal tract. With the vocal tract inter-channel area .

[0092] Next, the average flow velocity of the inter-channel area is determined based on the measured flow velocity values ​​of two adjacent channels using the following formula. This average velocity is then multiplied by the inter-channel area to obtain the inter-channel area flow rate:

[0093] ;

[0094] ;

[0095] in, For the vocal tract The measured flow velocity value, For the vocal tract The measured flow velocity value, For the vocal tract With the vocal tract Average flow velocity across the inter-channel area. For the vocal tract With the vocal tract The flow rate of the inter-channel area.

[0096] Step 13: Based on the logarithmic velocity formula and the measured velocity values ​​of the near-water surface channel, calculate the surface velocity, then calculate the average velocity of the near-water surface area, and multiply it by the near-water surface area to obtain the near-water surface area flow rate.

[0097] In the specific implementation, after completing the inter-channel calculations, the near-water surface calculations can proceed. The near-water surface calculations consist of two parts: the first part calculates the surface velocity, and the second part calculates the area flow rate near the surface. Based on the logarithmic velocity formula and the measured velocity values ​​of the near-water surface channels, the server calculates the surface velocity, then calculates the average velocity of the near-water surface area, and finally multiplies it by the area of ​​the near-water surface to obtain the area flow rate near the surface.

[0098] In one example, for calculating the surface velocity, the server needs to establish a logarithmic velocity formula based on Brandt's logarithm formula with the surface velocity as the base. The logarithmic velocity formula is expressed as:

[0099] ;

[0100] ;

[0101] in, Let be the line-average velocity at any horizontal line of the target river channel cross-section. For an unknown water surface velocity, For dynamic flow velocity, Kármán's constant, For relative water depth, It is the acceleration due to gravity. For hydraulic gradient, The water is deep.

[0102] Next, the audio channels Measured flow velocity in the near-water surface acoustic channel , channel Measured flow velocity Substituting these values ​​into the logarithmic formula for the vertical velocity distribution, we obtain the following about the vocal tract. Regarding the vocal tract Transformation formula:

[0103] ;

[0104] ;

[0105] in, It is the audio channel elevation The relative water depth at that location It is the audio channel elevation The relative water depth and acoustic channel That is, the sound channel near the water surface.

[0106] Finally, the following formula is used to analyze the relationship between the vocal tract and the vocal tract. Transformation formulas and about the vocal tract By solving the transformation formulas simultaneously, the surface velocity of the water can be determined. :

[0107] .

[0108] In one example, when the server calculates the area flow rate near the water surface, it first bases the calculation on the cross-sectional diagram of the target river channel and the near-water surface acoustic channel. elevation and water surface elevation ,get and The cross-sectional area between the two sections is used as the area near the water surface. Then, based on the near-water surface acoustic channel, the following formula is used. Measured flow velocity and water surface velocity Calculate the average flow velocity over the near-water surface area, then multiply by The flow rate of the near-water surface area is obtained as follows:

[0109] ;

[0110] ;

[0111] in, The average flow velocity is the area near the water surface. This refers to the flow rate of the area near the water surface.

[0112] Step 14: Accumulate the area flow rate near the riverbed, the area flow rate between the channels, and the area flow rate near the water surface to obtain the final cross-sectional flow rate of the river channel.

[0113] In practice, after calculating the area flow rate near the riverbed, the area flow rate between the channels, and the area flow rate near the water surface, the server can sum them up to obtain the final cross-sectional flow rate of the river channel.

[0114] In one example, the server accumulates the area flow near the riverbed, the area flow between the channels, and the area flow near the water surface to obtain the final river cross-sectional flow, which can be achieved using the following formula:

[0115] ;

[0116] in, The flow rate is the area near the riverbed. The flow rate is the area near the water surface. For the vocal tract With the vocal tract The flow rate of the inter-channel area.

[0117] In one example, the server can perform multiple calculations to obtain multiple river cross-sectional flows, and then take the average of the calculated multiple river cross-sectional flows as the final river cross-sectional flow.

[0118] The multi-channel river flow calculation method based on acoustic time difference proposed in this embodiment has at least the following advantages compared with traditional calculation methods.

[0119] First, this embodiment uses measured cross-sectional data and changes in the cross-section controlled by the channel layout to obtain a partial area, thereby eliminating the calculation error of the partial area between channels as much as possible and effectively improving the calculation accuracy of river flow.

[0120] Secondly, this embodiment uses a riverbed morphology coefficient calculated from river cross-section data to replace the manually given riverbed coefficient in the traditional calculation method, avoiding human arbitrariness and thus avoiding human error in the calculation of the area flow near the riverbed. At the same time, the riverbed morphology coefficient depends on the actual flow measurement cross-section, that is, it is calculated from the measured data. This fundamentally saves a lot of manpower, material resources and time that are consumed in the traditional calculation method of calibrating the riverbed coefficient using hydrological survey data.

[0121] Third, this embodiment uses the logarithmic velocity formula and on-site measured data to calculate the current water surface velocity, replacing the linear extrapolation calculation method in the traditional calculation method. This successfully solves the problem of excessive deviation in water surface velocity in high water sections, eliminates the arbitrary value of the water surface velocity adjustment coefficient, and fundamentally saves a lot of manpower, material resources and time spent on calibration coefficients using hydrological survey data in the traditional calculation method, effectively improving the calculation accuracy of the area flow rate near the water surface.

[0122] The steps described above are for clarity only. In implementation, they can be combined into one step, or some steps can be broken down into multiple steps, as long as they involve the same logical relationship, they are all within the scope of protection of this application. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, without changing the core design of the algorithm and process, are also within the scope of protection of this application.

[0123] Another embodiment of this application proposes a multi-channel river flow calculation system based on the acoustic time-of-flight method. The implementation details of this multi-channel river flow calculation system based on the acoustic time-of-flight method are described below. The following implementation details are provided for ease of understanding and are not essential for implementing this example. Figure 3 This is a schematic diagram of a multi-channel river flow calculation system based on acoustic time difference method proposed in this embodiment. The system includes: a near-bottom area flow calculation module 21, an inter-channel area flow calculation module 22, a near-water surface area flow calculation module 23, and an accumulation module 24.

[0124] The near-bottom area flow calculation module 21 is used to calculate the average flow velocity of the near-bottom area based on the obtained measured flow velocity value of the near-bottom channel and the riverbed morphology coefficient, and then multiply it by the near-bottom area to obtain the near-bottom area flow.

[0125] The inter-channel partial area flow rate calculation module 22 is used to determine the average flow rate of the inter-channel partial area based on the obtained measured flow rate values ​​of the two adjacent channels, and then multiply it by the inter-channel partial area to obtain the inter-channel partial area flow rate. The inter-channel partial area is determined based on the elevation of the two adjacent channels.

[0126] The near-water surface area flow rate calculation module 23 is used to calculate the water surface velocity based on the logarithmic velocity formula and the obtained measured velocity value of the near-water surface channel, and then calculate the average velocity of the near-water surface area, and then multiply it by the near-water surface area to obtain the near-water surface area flow rate.

[0127] Accumulation module 24 is used to accumulate the area flow near the riverbed, the area flow between the channels, and the area flow near the water surface to obtain the final river cross-sectional flow.

[0128] It is worth mentioning that all modules and units involved in this embodiment are logical modules. In practical applications, a logical module can be a physical unit, a part of a physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this application, this embodiment does not introduce units that are not closely related to solving the technical problems proposed in this application; however, this does not mean that other units are absent in this embodiment.

[0129] It is not difficult to see that this embodiment is a system embodiment corresponding to the above method embodiments, and this embodiment can be implemented in conjunction with the above method embodiments. The relevant technical details and technical effects mentioned in the above method embodiments are still valid in this embodiment, and will not be repeated here to reduce repetition. Accordingly, the relevant technical details mentioned in this embodiment can also be applied to the above method embodiments.

[0130] Another embodiment of this application provides an electronic device, such as Figure 4 As shown, it includes: at least one processor 31; and a memory 32 communicatively connected to the at least one processor 31; wherein the memory 32 stores instructions executable by the at least one processor 31, the instructions being executed by the at least one processor 31 to enable the at least one processor 31 to perform a multi-channel river flow calculation method based on acoustic time difference method as described in the above method embodiment.

[0131] The memory and processor are connected via a bus, which can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors and memories. The bus can also connect various other circuits, such as peripherals, voltage regulators, and power management circuits, which are well known in the art and will not be described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor is transmitted over the wireless medium via an antenna, which further receives data and transmits it to the processor.

[0132] The processor manages the bus and handles general processing, and also provides various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. The memory is used to store data used by the processor during operation.

[0133] Another embodiment of this application proposes a computer-readable storage medium storing a computer program that, when executed by a processor, can implement a multi-channel river flow calculation method based on acoustic time difference method as described in the above method embodiments.

[0134] That is, those skilled in the art will understand that all or part of the steps in the above method embodiments can be implemented by hardware related to program instructions. The program is stored in a storage medium and includes several instructions to cause a device (such as a microcontroller, chip) or processor to execute all or part of the steps of the multi-channel river flow calculation method based on acoustic time difference method described in the method embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.

[0135] It will be understood by those skilled in the art that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application. For those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A method for calculating multi-channel river flow based on acoustic travel time method, characterized in that, The method comprises the following steps: The near-bottom partial-area flow rate is calculated based on the measured flow rate of the near-bottom acoustic channel and the bottom shape coefficient, and then multiplied by the near-bottom partial area to obtain the near-bottom partial-area flow rate. The inter-channel partial-area flow rate is determined based on the measured flow rates of the two adjacent acoustic channels, and then multiplied by the inter-channel partial area to obtain the inter-channel partial-area flow rate, wherein the inter-channel partial area is determined based on the elevations of the two adjacent acoustic channels. The surface flow rate is calculated based on the logarithmic flow rate formula and the measured flow rate of the near-surface acoustic channel, and then the near-surface partial-area flow rate is calculated based on the surface flow rate, and then multiplied by the near-surface partial area to obtain the near-surface partial-area flow rate. The final river cross-section flow rate is obtained by accumulating the near-bottom partial-area flow rate, the inter-channel partial-area flow rate and the near-surface partial-area flow rate. The near-bottom partial-area flow rate is calculated based on the measured flow rate of the near-bottom acoustic channel and the bottom shape coefficient, and then multiplied by the near-bottom partial area to obtain the near-bottom partial-area flow rate. The riverbed form coefficient is determined by the following equation based on the area of the portion near the riverbed and the partial cross-sectional area between the initial riverbed elevation and the riverbed ​ ； wherein is the riverbed form coefficient; The near-bottom area average flow velocity is calculated based on the obtained measured flow velocity of the near-bottom sound channel and the river bottom shape coefficient by the following formula, and multiplied by to obtain the near-bottom area flow. ； ； wherein, is the near-bed partial-area flow rate, is the near-bed partial-area average flow velocity, is the measured flow velocity of the near-bed acoustic channel; The surface flow rate is calculated based on the logarithmic flow rate formula and the measured flow rate of the near-surface acoustic channel, and the surface flow rate is calculated based on the logarithmic flow rate formula. The logarithmic flow rate formula is established based on the surface flow rate, and the logarithmic flow rate formula is represented as: ； ； wherein, is the mean velocity of the river section of the target river at any horizontal line of the river section, is the unknown surface velocity of the water, is the dynamic velocity, is the Karman constant, is the relative depth of water, is the gravitational acceleration, is the hydraulic slope, is the water depth; The measured values of the flow rates of the sound channels , the measured values of the flow rates of the sound channels , the measured values of the flow rates of the sound channels , the measured values of the flow rates of the sound channels are substituted into the logarithmic formula of the vertical distribution of the flow rates, respectively, to obtain the transformation formula about the sound channels , the transformation formula about the sound channels . ； ； wherein is the relative water depth at the elevation of the sound channel is the relative water depth at the elevation of the sound channel i.e. the near-surface sound channel;​​ The following formula is used to describe the relationship between the vocal tract and the vocal tract. Transformation formulas and about the vocal tract Solve the transformation formulas simultaneously to find the surface velocity of the water. : 。 2. The method of claim 1, wherein the acoustic travel time method is based on a multi-channel river flow calculation method, characterized by, Before the near-bottom partial-area flow rate is calculated based on the measured flow rate of the near-bottom acoustic channel and the bottom shape coefficient, the following steps are further included: Sensors were deployed on both banks of the target river channel to set up [the target river channel]. Each channel has a specific elevation and flow velocity, and the measured values ​​of each channel are obtained; among them, the first channel... For the near-bottom sound channel, the first Each channel For near-water surface sound channel, It is an integer greater than 2; Based on the river cross-section map of the target river, the near-bed portion area is obtained , the near-bed portion area is the portion cross-sectional area between the near-bed acoustic channel and the riverbed; based on the near-bottom sound channel elevation, the near-bottom sound channel width, and the near-bottom portion area , the initial river bottom elevation is derived, and based on the river channel section map of the target river channel, the partial section area between the initial river bottom elevation and the river bed is obtained ; The initial bottom elevation is calculated by the formula: ； wherein, is the calculated initial riverbed elevation, is the elevation of the near riverbed sound channel, is the width of the near riverbed sound channel, is the near riverbed portion area; Obtain water surface elevation ,Will and The difference between them is taken as the water depth of the target river channel.

3. The method of claim 2, wherein the method is based on the acoustic travel time method. For two adjacent channels and Determination of the inter-channel partial area flow rate based on the obtained flow rate measured values of the two adjacent channels, and multiplication by the inter-channel partial area, to obtain the inter-channel partial area flow rate, includes: Based on the river channel cross-section diagram and sound channel of the target river elevation Harmony Channel elevation ,get and The cross-sectional area of ​​the middle section is used as the vocal tract. With the vocal tract inter-channel area ; The inter-channel partial-area flow rate is determined based on the measured flow rates of the two adjacent acoustic channels, and then multiplied by the inter-channel partial area to obtain the inter-channel partial-area flow rate. ； ； wherein is the flow rate measured value for the sound channel is the flow rate measured value for the sound channel is the flow rate measured value for the sound channel is the flow rate measured value for the sound channel is the inter-channel partial area average flow rate for the sound channel is the inter-channel partial area average flow rate for the sound channel is the inter-channel partial area flow rate for the sound channel is the inter-channel partial area flow rate for the sound channel is the inter-channel partial area flow rate for the sound channel is the inter-channel partial area flow rate for the sound channel 4. The method of claim 3, wherein the method is based on the acoustic travel time method. The near-surface partial-area flow rate is calculated based on the surface flow rate, and then multiplied by the near-surface partial area to obtain the near-surface partial-area flow rate. Based on the river channel cross-section diagram and near-water acoustic channel elevation and water surface elevation ,get and The cross-sectional area between the two sections is used as the area near the water surface. ; Based on the near-water surface acoustic channel, the following formula is used. Measured flow velocity and water surface velocity Calculate the average flow velocity over the near-water surface area, then multiply by The flow rate of the near-water surface area is obtained as follows: ； ； wherein, is the area-averaged flow velocity in the near-surface portion, is the area flow in the near-surface portion.

5. A method for calculating multi-channel river flow based on acoustic travel time method according to any one of claims 2 to 4, characterized in that, The final river cross-section flow rate is obtained by accumulating the near-bottom partial-area flow rate, the inter-channel partial-area flow rate and the near-surface partial-area flow rate, which is realized by the following formula: ； wherein, is the near-bed partial area flow rate, is the near-surface partial area flow rate, is the sound channel is the sound channel is the inter-channel partial area flow rate.

6. A multi-channel river flow rate calculation system based on an acoustic travel time method, characterized by, The method comprises the following steps: The near-bottom partial-area flow rate is calculated based on the measured flow rate of the near-bottom acoustic channel and the bottom shape coefficient, and then multiplied by the near-bottom partial area to obtain the near-bottom partial-area flow rate. The inter-channel partial-area flow rate is determined based on the measured flow rates of the two adjacent acoustic channels, and then multiplied by the inter-channel partial area to obtain the inter-channel partial-area flow rate, wherein the inter-channel partial area is determined based on the elevations of the two adjacent acoustic channels. The surface flow rate is calculated based on the logarithmic flow rate formula and the measured flow rate of the near-surface acoustic channel, and then the near-surface partial-area flow rate is calculated based on the surface flow rate, and then multiplied by the near-surface partial area to obtain the near-surface partial-area flow rate. The final river cross-section flow rate is obtained by accumulating the near-bottom partial-area flow rate, the inter-channel partial-area flow rate and the near-surface partial-area flow rate. Based on the obtained flow velocity measured value of the near river bottom sound channel and the river bottom shape coefficient, the near river bottom part area average flow velocity is calculated, and then multiplied by the near river bottom part area to obtain the near river bottom part area flow, including: The riverbed form coefficient is determined by the following equation based on the area of the portion near the riverbed and the partial cross-sectional area between the initial riverbed elevation and the riverbed ​ ； wherein is the riverbed form coefficient; The near-bottom area average flow velocity is calculated based on the obtained measured flow velocity of the near-bottom sound channel and the river bottom shape coefficient by the following formula, and multiplied by to obtain the near-bottom area flow. ； ； wherein, is the near-bed partial-area flow rate, is the near-bed partial-area average flow velocity, is the measured flow velocity of the near-bed channel. Based on the logarithmic flow velocity formula and the obtained flow velocity measured value of the near water surface sound channel, the water surface flow velocity is calculated, including: Based on the Brant logarithmic formula with the water surface flow velocity as the base, the logarithmic flow velocity formula is established, and the logarithmic flow velocity formula is expressed as: ； ； wherein, is the mean velocity of the arbitrary horizontal line of the river section of the target river, is the unknown water surface velocity, is the dynamic velocity, is the Karman constant, is the relative water depth, is the gravitational acceleration, is the hydraulic slope, is the water depth; The measured values of the flow rates of the sound channels The measured values of the flow rates of the sound channels The measured values of the flow rates of the sound channels The measured values of the flow rates of the sound channels are substituted into the logarithmic formula of the vertical distribution of the flow rates, respectively, to obtain the transformation formula about the sound channels about the sound channels ​ ； ； wherein is the relative water depth at the elevation of the sound channel is the relative water depth at the elevation of the sound channel i.e. the near-surface sound channel;​​ The following formula is used to describe the relationship between the vocal tract and the vocal tract. Transformation formulas and about the vocal tract Solve the transformation formulas simultaneously to find the surface velocity of the water. : 。 7. An electronic device, comprising: Including: At least one processor; And a memory connected in communication with the at least one processor; Wherein the memory has instructions stored therein, which can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the multi-channel river flow calculation method based on the acoustic time difference method as claimed in any one of claims 1 to 5.

8. A computer readable storage medium storing a computer program, characterized in that, The computer program is executed by the processor to implement the multi-channel river flow calculation method based on the acoustic time difference method as claimed in any one of claims 1 to 5.

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