Hydrological information prediction method for hydraulic engineering

Abstract

The invention relates to the technical field of water conservancy surveying and mapping, in particular to a water conservancy project-oriented hydrological information prediction method, which comprises the following steps of: installing an ultrasonic detection device and acquiring an ultrasonic signal and inclination angle data of each reflecting plate, calculating the vibration degree of a reflecting plate bracket, and analyzing the frequency change characteristics of the ultrasonic signal; adjusting the inclination angles of the reflecting plates in combination with the vibration degrees to obtain the actual inclination angles of the reflecting plates, and calculating the actual reflecting distance of any reflecting plate, the ultrasonic initial velocity at the ultrasonic probe and the attenuation rate of the ultrasonic signal, so as to obtain the height from the liquid level to the ultrasonic probe; and liquid level height prediction is carried out by using a prediction algorithm. According to the invention, accurate real-time liquid level information and prediction results are provided.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy surveying and mapping, and in particular to a hydrological information prediction method for water conservancy projects. Background Art

[0002] Liquid level monitoring and prediction is a key link to ensure the safe operation, efficient management and disaster prevention of water conservancy projects. It is of great significance to ensure the stability of reservoir dams, bridge construction safety, and optimize irrigation system management. The prediction process includes non-contact measurement, deep learning prediction and other processes. The accuracy of measurement data is the cornerstone of accurate prediction. It is necessary to consider many influencing factors to ensure the reliability of data as much as possible.

[0003] The existing prediction of liquid level height data is made by measuring the liquid level height sequence. However, when the liquid level is generally measured by ultrasound, the actual sound velocity is measured using a reflective baffle to obtain the liquid level height. When calculating the sound velocity, the influence of the actual wind force on the reflective baffle offset and vibration is ignored, and the change of the sound velocity in the vertical direction is also ignored. It is generally believed that the sound velocity is constant, but in fact, the closer to the water surface, the greater the air humidity and the smaller the sound velocity; ultimately leading to inaccurate calculation of the liquid level height data. Summary of the invention

[0004] The invention provides a hydrological information prediction method for water conservancy projects to solve the existing problems.

[0005] The hydrological information prediction method for water conservancy projects of the present invention adopts the following technical solutions: An embodiment of the present invention provides a hydrological information prediction method for a water conservancy project, the method comprising the following steps: An ultrasonic detection device including an ultrasonic probe, two reflectors and a reflector bracket is installed, the two reflectors are respectively referred to as reflector 1 and reflector 2, and an ultrasonic signal and inclination data of each reflector are obtained; The vibration degree of the reflector bracket is calculated according to the change of the inclination angle data of the two reflectors, the frequency change characteristics of the ultrasonic signal are analyzed, and the inclination angle of each reflector is adjusted in combination with the vibration degree of the reflector bracket when the ultrasonic probe transmits the ultrasonic signal to obtain the actual inclination angle of each reflector; the actual reflection distance of any reflector is calculated based on the actual inclination angle of any reflector and the geometric principle of triangle; When the ultrasonic probe transmits an ultrasonic signal at any time, the ultrasonic initial velocity at the ultrasonic probe and the attenuation rate of the ultrasonic signal are calculated according to the actual reflection distance of the two reflectors and the time when the ultrasonic probe transmits and receives the ultrasonic signal; The height of the liquid level from the ultrasonic probe is obtained by combining the ultrasonic initial velocity at the ultrasonic probe, the attenuation rate of the ultrasonic signal, and the time for the ultrasonic probe to receive the ultrasonic signal; Data prediction is performed using a prediction algorithm based on the height of the liquid level from the ultrasonic probe each time the ultrasonic probe emits an ultrasonic signal.

[0006] Furthermore, the specific method of calculating the vibration degree of the reflector bracket according to the change of the inclination angle data of the two reflectors includes: The moment corresponding to each time the ultrasonic probe transmits an ultrasonic signal is recorded as the ultrasonic moment. The ultrasonic moment is used as the segmentation point of any inclination data, and the arbitrary inclination data is divided into several inclination data segments. According to the difference in inclination data of different reflectors when the ultrasonic probe transmits ultrasonic signals any number of times and the difference in inclination of the reflectors at different moments, the vibration degree of the reflector bracket under the corresponding number of ultrasonic transmissions is obtained.

[0007] Furthermore, the specific calculation method of the vibration degree is: In the formula, Indicates that the ultrasound probe is The vibration degree of the reflector bracket when the ultrasonic signal is emitted for the first time; Indicates that the ultrasound probe is The number of data points in the inclination data segment when the ultrasonic signal is emitted for the first time; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time, the inclination data segment of the reflector 1 Data points at a certain moment; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time, the inclination data segment of the reflector 2 Data points at a certain moment; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time and The tilt fluctuation parameter at each moment; Represents the absolute value symbol.

[0008] Furthermore, the specific method for obtaining the tilt fluctuation parameter is: The average values ​​of the inclination angles of the reflector 1 and the reflector 1 at any time are obtained, and the inclination fluctuation parameter is obtained according to the difference between the average values ​​of the inclination angles at adjacent time points.

[0009] Furthermore, the analysis of the frequency change characteristics of the ultrasonic signal and the adjustment of the inclination angle of each reflector in combination with the vibration degree of the reflector bracket when the ultrasonic probe transmits the ultrasonic signal to obtain the actual inclination angle of each reflector include the following specific methods: Gaussian filtering is used to smooth and denoise the ultrasonic signal transmitted and received by the ultrasonic probe, and the frequencies corresponding to the ultrasonic signal at the time of transmission, the first transmission, and the second reflection are obtained respectively; According to the frequency change of the ultrasonic signal before and after emission and reflection, and in combination with the vibration degree of the reflector bracket when the ultrasonic probe emits the ultrasonic signal, the inclination angle of the reflector is adjusted to obtain the actual inclination angle of any reflector.

[0010] Furthermore, the actual reflection distance of any reflector is calculated based on the actual inclination angle of any reflector and the geometric principle of triangle, including the specific method of: The specific calculation method of the actual reflection distance of any reflector is: in, Indicates that the ultrasound probe is The actual reflection distance of the reflector when the ultrasonic signal is emitted for the first time; Indicates the length of the reflector; Indicates that the ultrasound probe is The actual inclination angle of the reflector when the ultrasonic signal is emitted for the first time; Represents the cosine function.

[0011] Furthermore, the specific method of calculating the ultrasonic initial velocity and the attenuation rate of the ultrasonic signal at the ultrasonic probe according to the actual reflection distance of the two reflectors and the time for the ultrasonic probe to transmit and receive the ultrasonic signal includes: The actual reflection distances of the reflector 1 and the reflector 2 are obtained respectively, and half of the time from when the ultrasonic probe transmits the ultrasonic signal to when it receives the ultrasonic signal for the first time is recorded as the first sound path time, and half of the time from when the ultrasonic probe transmits the ultrasonic signal to when it receives the ultrasonic signal for the second time is recorded as the second sound path time; The ultrasonic initial velocity at the ultrasonic probe and the attenuation rate of the ultrasonic signal are obtained by combining the first sound path time, the second sound path time, the actual reflection distances of the reflector 1 and the reflector 2, and the attenuation rate of the ultrasonic signal.

[0012] Furthermore, the method of combining the ultrasonic initial velocity at the ultrasonic probe, the attenuation rate of the ultrasonic signal, and the time for the ultrasonic probe to receive the ultrasonic signal to obtain the height of the liquid level from the ultrasonic probe includes the following specific methods: The specific calculation method of the height of the liquid level from the ultrasonic probe is: in, Indicates that the ultrasound probe is The height of the liquid level from the ultrasonic probe when the ultrasonic signal is emitted for the first time; Indicates that the ultrasound probe is The initial ultrasonic velocity at the ultrasonic probe when the ultrasonic signal is emitted for the first time; Indicates the third sound path time; Indicates that the ultrasound probe is The attenuation rate of the ultrasonic signal when the ultrasonic signal is emitted for the first time.

[0013] Furthermore, the data prediction is performed using a prediction algorithm based on the height of the liquid level from the ultrasonic probe when the ultrasonic probe emits an ultrasonic signal each time, and the specific method includes: The sequence formed by the height of the liquid level from the ultrasonic probe when the ultrasonic probe emits ultrasonic signals all times is obtained, which is recorded as the liquid level height sequence. The EMD-LSTM algorithm is used to predict the liquid level height sequence.

[0014] Furthermore, after calculating the vibration degree of the reflector bracket, the method further includes normalizing the vibration degree using a sigmoid function.

[0015] The beneficial effect of the technical solution of the present invention is that the embodiment of the present invention can compensate for the influence of environmental and equipment vibrations by analyzing the inclination changes of the reflector and the frequency characteristics of the ultrasonic signal, thereby improving the measurement accuracy. In particular, under the influence of the vibration of the reflector bracket, by calculating the vibration degree and dynamically adjusting it, the actual inclination of the reflector can be effectively corrected to ensure that the reflection distance and liquid level are measured more accurately. In addition, by obtaining the inclination data of the reflector and the feedback of the ultrasonic signal in real time, the measurement parameters can be dynamically adjusted to reflect the changes in the liquid level in real time. The ultrasonic probe obtains the liquid level height information each time it transmits a signal, and performs a comprehensive analysis in combination with the ultrasonic initial velocity, attenuation rate and other data, thereby providing accurate real-time liquid level information and prediction results. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a flow chart of the steps of the hydrological information prediction method for water conservancy projects of the present invention; Figure 2 This is a schematic diagram of the installation of the ultrasonic detection device; Figure 3 Schematic diagram of ultrasound signal. DETAILED DESCRIPTION

[0018] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the hydrological information prediction method for water conservancy projects proposed by the present invention, its specific implementation method, structure, features and effects, in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0019] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0020] The specific scheme of the hydrological information prediction method for water conservancy projects provided by the present invention is described in detail below with reference to the accompanying drawings.

[0021] See also Figure 1 , which shows a flow chart of the steps of a hydrological information prediction method for a water conservancy project provided by an embodiment of the present invention, the method comprising the following steps: Step S001: Install an ultrasonic detection device including an ultrasonic probe, two reflectors and a reflector bracket, the two reflectors are respectively referred to as reflector 1 and reflector 2, and obtain ultrasonic signals and inclination data of each reflector.

[0022] It should be noted that liquid level measurement is an important test method for liquid level measurement in the field of water conservancy projects. It is widely used in various containers, liquid level measurement in pipelines, and water level measurement in reservoirs, rivers, and canals. Common ultrasonic level meters generally use a ceramic ultrasonic transducer that combines transmission and reception, and the transmission and reception of sound waves are completed by the same probe. The probe transmits an ultrasonic signal to the measured liquid surface, and the ultrasonic wave is transmitted from the probe to the measured liquid surface through the propagation medium, forming a reflection on the liquid surface. The reflected wave propagates along the original path to the probe and is absorbed by the probe. The timing unit measures the time taken for the ultrasonic wave to be transmitted and received from the echo. According to the propagation speed of the sound wave in the air, the distance from the probe to the liquid surface can be calculated, thereby obtaining the height of the liquid surface. However, when using ultrasonic waves for liquid level measurement, the measurement results of the ultrasonic level meter are easily affected by the actual measurement environment, which may cause errors. Therefore, the embodiment of the present invention proposes a hydrological information prediction method for water conservancy projects to improve the accuracy of the measurement results of the ultrasonic level meter.

[0023] Specifically, in order to implement the hydrological information prediction method for water conservancy projects proposed in this embodiment, it is first necessary to install an ultrasonic detection device and collect relevant data. The specific process is as follows: First, an ultrasonic detection device is installed at the location of the river entering the reservoir. The ultrasonic detection device includes: an integrated transceiver ultrasonic probe, two reflective plates and a bracket (i.e., a support frame), and the inclination angle of the ultrasonic detection device is obtained through a tilt sensor (the inclination angle of the ultrasonic detection device is the inclination angle corresponding to when the vertical bracket of the ultrasonic detection device is tilted). The two reflective plates are respectively called reflective plate 1 and reflective plate 2. The integrated transceiver ultrasonic probe transmits ultrasonic waves to the water surface and receives ultrasonic waves reflected by the water surface. The reflective plates are used to form a sound path interval with a fixed distance from the probe. This structure is called a sound path frame. When the ultrasonic probe transmits sound waves, the reflective plate can reflect part of the sound waves back to the probe. After the probe receives the reflected wave, it calculates the time from transmission to reception, and calculates the speed of sound. Figure 2 Shown is a schematic diagram of the installation of the ultrasonic detection device.

[0024] It should be noted that the sampling frequency of the inclination sensor is selected to be 200Hz, and the ultrasonic signal transmission frequency of the ultrasonic level meter probe is not greater than 10Hz; the distances between the reflector 1 and the reflector 2 and the ultrasonic probe need to be adjusted, and generally the water surface height should be ensured not to exceed the reflector 2.

[0025] Then, ultrasonic waves are emitted to the liquid surface through the ultrasonic probe, and the inclination data of the reflection plate 1 and the reflection plate 2 are acquired through the inclination sensor, and the inclination data are time series data.

[0026] It should be noted that when the ultrasonic detection device is used to measure the liquid level, the ultrasonic signal emitted by the ultrasonic probe will have three reflection processes, namely, the reflection process of the ultrasonic signal by the reflection plate 1, the reflection plate 2 and the water surface respectively.

[0027] So far, the ultrasonic detection device and ultrasonic signal are obtained through the above method.

[0028] Step S002: Calculate the vibration degree of the reflector bracket according to the change of the inclination angle data of the two reflectors, analyze the frequency change characteristics of the ultrasonic signal, and adjust the inclination angle of each reflector in combination with the vibration degree of the reflector bracket when the ultrasonic probe transmits the ultrasonic signal to obtain the actual inclination angle of each reflector; calculate the actual reflection distance of any reflector based on the actual inclination angle of any reflector and the geometric principle of triangle.

[0029] It should be noted that when ultrasonic probes are usually used to ultrasonically measure the liquid level, the ultrasonic probe is located on the water surface. However, the measurement will be affected by the environment. For example, when the reflector is disturbed by air, the ultrasonic signal reflected by the reflector changes. In addition, the ultrasonic signal will be affected by air humidity, resulting in inaccurate results of ultrasonic measurement of the liquid level. As for the vibration of the reflector caused by wind, when the signal is reflected, the vibration is close to the ultrasonic probe, which will cause the frequency of the reflected signal to increase. As for the air humidity on the river surface, the closer to the river surface, the greater the humidity of the air, and the smaller the speed of the ultrasonic signal. Therefore, the embodiment of the present invention obtains the inclination angle and reflection distance of the actual reflected ultrasonic signal by analyzing the change of the inclination angle and the relationship between the ultrasonic frequency, thereby calculating the initial sound velocity and the attenuation rate of the sound velocity of the ultrasonic signal during measurement; finally, the real-time height of the ultrasonic probe from the liquid surface is obtained.

[0030] It should be noted that when installing the measuring reflector, the reflector needs to be measured vertically downward. However, in actual operation, due to installation errors, long-term use, wind and other factors, the reflector bracket may tilt, resulting in changes in the actual ultrasonic reflection distance of the measuring reflector. When the tilted reflector reflects ultrasound, the sound path of the ultrasonic reflection is shortened compared to when it was not tilted, and the shortened reflection distance is related to the tilt angle. Generally, the larger the tilt angle, the shorter the reflection distance.

[0031] Specifically, in step S201, the vibration degree of the reflector bracket is calculated according to the change of the inclination angle data of the two reflectors.

[0032] It should be noted that the inclination sensors are located at the connection of the two baffles of the bracket. If the change trend of the two sensors fluctuates greatly and the difference between the data is small, it means that the measurement data is more accurate and the vibration is greater. The sampling frequency of the inclination sensor is generally higher than the transmission frequency of the ultrasonic probe. Each transmission of the ultrasonic signal is used as the breakpoint of the segmentation interval, and the inclination change between the two ultrasonic signals is calculated to obtain the inclination degree of the reflector support frame within the segment (that is, the inclination signal is segmented and windowed according to the frequency of the ultrasonic signal).

[0033] Firstly, the moment corresponding to each time the ultrasonic probe transmits an ultrasonic signal is obtained and recorded as the ultrasonic moment. The ultrasonic moment is used as the segmentation point of any inclination data, and the arbitrary inclination data is divided into several inclination data segments. According to the difference in inclination data of different reflectors when the ultrasonic probe transmits ultrasonic signals any number of times and the difference in inclination of the reflectors at different moments, the vibration degree of the reflector bracket under the corresponding number of ultrasonic transmissions is obtained.

[0034] As an embodiment, the specific calculation method of the vibration degree is: In the formula, Indicates that the ultrasound probe is The vibration degree of the reflector bracket when the ultrasonic signal is emitted for the first time; Indicates that the ultrasound probe is The number of data points in the inclination data segment when the ultrasonic signal is emitted for the first time; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time, the inclination data segment of the reflector 1 Data points at a certain moment; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time, the inclination data segment of the reflector 2 Data points at a certain moment; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time and The tilt fluctuation parameter at each moment; Represents the absolute value symbol.

[0035] It should be noted that the tilt fluctuation parameter reflects the vibration of the two reflectors on the reflector bracket. The larger the tilt fluctuation parameter, the more violent the inclination of the reflector on the reflector bracket is, which means that the reflector is more affected by air disturbance. It indicates the difference between the data points in the inclination data corresponding to the reflector 1 and the reflector 2 engraved at the same time. The smaller the difference is, the higher the accuracy of the data measurement is. The method for obtaining the tilt fluctuation parameter is as follows: obtaining the average tilt angle of the reflector 1 and the reflector 2 at any time, and obtaining the tilt fluctuation parameter according to the difference between the average tilt angles at adjacent time points.

[0036] As an embodiment, the specific calculation method of the tilt fluctuation parameter is: in, Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time and The tilt fluctuation parameter at each moment; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time, the inclination data segment of the reflector 1 Data points at a certain moment; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time, the inclination data segment of the reflector 2 Data points at a certain moment; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time, the inclination data segment of the reflector 1 Data points at a certain moment; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time, the inclination data segment of the reflector 2 Data points at a certain moment; Represents the absolute value symbol.

[0037] It should be noted that Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time, The overall inclination value of the two reflectors on the reflector bracket at a certain moment.

[0038] Then, the vibration degree is normalized using a sigmoid function.

[0039] Step S202 , analyzing the frequency variation characteristics of the ultrasonic signal, and adjusting the inclination angle of each reflector in combination with the vibration degree of the reflector bracket when the ultrasonic probe transmits the ultrasonic signal, to obtain the actual inclination angle of each reflector.

[0040] It should be noted that when using the inclination sensor to measure the inclination of the reflective baffle bracket, the wind along the river channel is generally strong, causing the bracket to vibrate to a certain extent. The inclination sensor data is determined by the change in the direction of the gravity block component force. Therefore, if the wind is strong, the inclination data will fluctuate greatly. The greater the fluctuation, the higher the uncertainty of the inclination angle position when the ultrasonic wave is reflected, and the greater the error of the mean inclination angle. Therefore, it is necessary to correct the inclination according to the ultrasonic signal. In addition, due to the ultrasonic Doppler effect, when the reflector vibrates against the sound source, the ultrasonic frequency received by the ultrasonic probe will increase; conversely, when the reflector is away from the sound source, the ultrasonic frequency received by the ultrasonic probe will decrease.

[0041] Firstly, Gaussian filtering is used to smooth and denoise the ultrasonic signal transmitted and received by the ultrasonic probe, and the frequencies corresponding to the ultrasonic signal at the time of transmission, the first transmission and the second reflection are obtained respectively.

[0042] It should be noted that if Figure 3 The figure shows a schematic diagram of an ultrasonic signal, which shows the change process of the ultrasonic signal after it is emitted by the ultrasonic probe and reflected by the reflector 1 and the reflector 2. When the ultrasonic signal emitted by the ultrasonic probe is reflected, if the frequency of the reflected signal is greater than the frequency of the emitted signal, it means that when the signal is reflected, the reflector vibrates closer to the ultrasonic probe, and the inclination angle relative to the mean is enlarged.

[0043] Then, the inclination angle of the reflector is adjusted according to the frequency change of the ultrasonic signal before and after emission and reflection, and in combination with the vibration degree of the reflector bracket when the ultrasonic probe emits the ultrasonic signal, to obtain the actual inclination angle of any reflector.

[0044] As an embodiment, the specific calculation method of the actual inclination angle of any reflector is as follows: in, Indicates that the ultrasound probe is The actual inclination angle of the reflector when the ultrasonic signal is emitted for the first time; Indicates that the ultrasound probe is The average value of the data points at all times in the inclination data segment of the reflector when the ultrasonic signal is emitted for the first time; Indicates that the ultrasound probe is The vibration degree of the reflector bracket when the ultrasonic signal is emitted for the first time (i.e. the normalized vibration degree); Indicates the frequency of ultrasonic signals emitted by the ultrasonic probe; Represents the average frequency of the ultrasonic signal reflected by reflector 1 and reflector 2.

[0045] Step S203 , calculating the actual reflection distance of any reflector in combination with the actual inclination angle of any reflector and based on the geometric principle of triangles.

[0046] As an embodiment, a specific method for calculating the actual reflection distance of any reflector is as follows: in, Indicates that the ultrasound probe is The actual reflection distance of the reflector when the ultrasonic signal is emitted for the first time; Indicates the length of the reflector; Indicates that the ultrasound probe is The actual inclination angle of the reflector when the ultrasonic signal is emitted for the first time; Represents the cosine function.

[0047] It should be noted that the embodiment of the present invention can further calculate the actual inclination angle of the reflector by detecting the frequency change of the ultrasonic signal during transmission and reflection, which can eliminate the influence of vibration interference on the inclination sensor and improve the accuracy of the reflection distance calculation. Specifically, by calculating the reflection distance through the geometric principle of the triangle and the actual inclination angle of the reflector, it can ensure that the calculation result of the reflection distance of the reflector is more accurate, especially in a complex vibration environment.

[0048] So far, the actual reflection distances of all reflection plates are obtained through the above method.

[0049] Step S003: When the ultrasonic probe transmits an ultrasonic signal at any time, the ultrasonic initial velocity at the ultrasonic probe and the attenuation rate of the ultrasonic signal are calculated according to the actual reflection distance of the two reflectors and the time for the ultrasonic probe to transmit and receive the ultrasonic signal.

[0050] It should be noted that, usually when measuring the water level, the ultrasonic probe is located above the water surface. However, the closer to the water surface, the higher the air humidity at the corresponding position. The higher the air humidity, the lower the speed of sound during the propagation of ultrasound. Therefore, the closer to the water surface, the greater the humidity, which causes the sound speed to attenuate during ultrasonic measurement. That is, the closer to the water surface, the greater the local air humidity, resulting in a lower sound transmission rate. It is generally believed that the sound attenuation rate caused by air humidity in the lower range of the river surface is fixed. Therefore, according to the actual reflection distance calculated above and the measurement time, the initial velocity and sound attenuation rate of the ultrasonic probe when transmitting the signal are obtained respectively.

[0051] Specifically, as an embodiment, a specific method for obtaining the ultrasonic initial velocity and the attenuation rate of the ultrasonic signal at the ultrasonic probe includes: First, the actual reflection distances of reflector 1 and reflector 2 are obtained respectively, and half of the time from the ultrasonic probe transmitting the ultrasonic signal to the first receiving the ultrasonic signal is recorded as the first sound path time, and half of the time from the ultrasonic probe transmitting the ultrasonic signal to the second receiving the ultrasonic signal is recorded as the second sound path time.

[0052] Then, the ultrasonic initial velocity at the ultrasonic probe and the attenuation rate of the ultrasonic signal are obtained by combining the first sound path time, the second sound path time, the actual reflection distances of the reflector 1 and the reflector 2, and the attenuation rate of the ultrasonic signal.

[0053] As an embodiment, when the ultrasonic probe transmits an ultrasonic signal at any time, a specific method for calculating the ultrasonic initial velocity at the ultrasonic probe and the attenuation rate of the ultrasonic signal is as follows: in, Indicates the ultrasonic initial velocity at the ultrasonic probe; Indicates the actual reflection distance of the reflector 1; Indicates the first sound path time; Indicates the actual reflection distance of the reflector 2; Indicates the second sound path time; Indicates the attenuation rate of the ultrasonic signal.

[0054] So far, the ultrasonic initial velocity and the sound attenuation rate at the ultrasonic probe are obtained by the above method.

[0055] Step S004: The height of the liquid level from the ultrasonic probe is obtained by combining the ultrasonic initial velocity at the ultrasonic probe, the attenuation rate of the ultrasonic signal, and the time for the ultrasonic probe to receive the ultrasonic signal.

[0056] Specifically, as an embodiment, the specific method for calculating the height of the liquid level from the ultrasonic probe is: in, Indicates that the ultrasound probe is The height of the liquid level from the ultrasonic probe when the ultrasonic signal is emitted for the first time; Indicates that the ultrasound probe is The initial ultrasonic velocity at the ultrasonic probe when the ultrasonic signal is emitted for the first time; Indicates the third sound path time; Indicates that the ultrasound probe is The attenuation rate of the ultrasonic signal when the ultrasonic signal is emitted for the first time.

[0057] The third sound path time is half of the time from when the ultrasonic probe transmits the ultrasonic signal to when it receives the ultrasonic signal for the third time, and is recorded as the third sound path time.

[0058] It should be noted that the embodiment of the present invention introduces multiple factors such as ultrasonic initial velocity, attenuation rate and third sound path time for correction, so as to take into account the possible changes and errors in the ultrasonic propagation process in liquid level measurement, especially the influence of attenuation effect on ultrasonic signal, thereby improving the accuracy of liquid level measurement.

[0059] Thus, the height of the liquid level from the ultrasonic probe is obtained each time the ultrasonic probe transmits an ultrasonic signal.

[0060] Step S005: Perform data prediction using a prediction algorithm based on the height of the liquid level from the ultrasonic probe each time the ultrasonic probe transmits an ultrasonic signal.

[0061] The sequence of the height of the liquid level from the ultrasonic probe when the ultrasonic probe emits ultrasonic signals for all times is obtained, which is recorded as the liquid level height sequence. The liquid level height sequence is predicted using the EMD-LSTM algorithm. The specific method is as follows: Firstly, median filtering is used to preprocess the liquid level height sequence.

[0062] Then, the liquid level height sequence is decomposed by EMD, and each decomposed feature sequence is predicted using the LSTM model.

[0063] Finally, the predicted values ​​of each sequence are superimposed to obtain the prediction information of the liquid level height sequence.

[0064] It should be noted that the EMD-LSTM algorithm is an existing time series prediction algorithm. The algorithm decomposes the original time series data into a series of IMF sequences (intrinsic mode functions) and a residual sequence through EMD (empirical mode decomposition), and then inputs each IMF sequence into the LSTM network (long short-term memory neural network) for prediction. Finally, the prediction results of each subsequence are superimposed to obtain the final prediction result. The specific implementation process of the algorithm is not described in detail in the embodiment of the present invention.

[0065] At this point, this embodiment is completed.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A hydrological information prediction method for water conservancy projects, characterized in that: The method comprises the following steps: An ultrasonic detection device including an ultrasonic probe, two reflectors and a reflector bracket is installed, the two reflectors are respectively referred to as reflector 1 and reflector 2, and an ultrasonic signal and inclination data of each reflector are obtained; The vibration degree of the reflector bracket is calculated according to the change of the inclination angle data of the two reflectors, the frequency change characteristics of the ultrasonic signal are analyzed, and the inclination angle of each reflector is adjusted in combination with the vibration degree of the reflector bracket when the ultrasonic probe transmits the ultrasonic signal to obtain the actual inclination angle of each reflector; the actual reflection distance of any reflector is calculated based on the actual inclination angle of the reflector and the geometric principle of the triangle; When the ultrasonic probe transmits an ultrasonic signal at any time, the ultrasonic initial velocity at the ultrasonic probe and the attenuation rate of the ultrasonic signal are calculated according to the actual reflection distance of the two reflectors and the time when the ultrasonic probe transmits and receives the ultrasonic signal; The height of the liquid level from the ultrasonic probe is obtained by combining the ultrasonic initial velocity at the ultrasonic probe, the attenuation rate of the ultrasonic signal, and the time for the ultrasonic probe to receive the ultrasonic signal; Data prediction is performed using a prediction algorithm based on the height of the liquid level from the ultrasonic probe each time the ultrasonic probe emits an ultrasonic signal.

2. The hydrological information prediction method for water conservancy projects according to claim 1 is characterized in that: The specific method of calculating the vibration degree of the reflector bracket according to the change of the inclination angle data of the two reflectors includes: The moment corresponding to each time the ultrasonic probe transmits an ultrasonic signal is recorded as the ultrasonic moment. The ultrasonic moment is used as the segmentation point of any inclination data, and the arbitrary inclination data is divided into several inclination data segments. According to the difference in inclination data of different reflectors when the ultrasonic probe transmits ultrasonic signals any number of times and the difference in inclination of the reflectors at different moments, the vibration degree of the reflector bracket under the corresponding number of ultrasonic transmissions is obtained.

3. The hydrological information prediction method for water conservancy projects according to claim 2 is characterized in that: The specific calculation method of the vibration degree is: In the formula, Indicates that the ultrasound probe is The vibration degree of the reflector bracket when the ultrasonic signal is emitted for the first time; Indicates that the ultrasound probe is The number of data points in the inclination data segment when the ultrasonic signal is emitted for the first time; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time, the inclination data segment of the reflector 1 Data points at a certain moment; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time, the inclination data segment of the reflector 2 Data points at a certain moment; Indicates that the ultrasound probe is When the ultrasonic signal is emitted for the first time and The tilt fluctuation parameter at each moment; Represents the absolute value symbol.

4. The hydrological information prediction method for water conservancy projects according to claim 3 is characterized in that: The specific method for obtaining the tilt fluctuation parameter is: The average inclination angles of the reflector 1 and the reflector 2 at any time are obtained, and the tilt fluctuation parameter is obtained according to the difference between the average inclination angles at adjacent time points.

5. The hydrological information prediction method for water conservancy projects according to claim 1 is characterized in that: The specific method of analyzing the frequency change characteristics of the ultrasonic signal and adjusting the inclination angle of each reflector in combination with the vibration degree of the reflector bracket when the ultrasonic probe transmits the ultrasonic signal to obtain the actual inclination angle of each reflector includes: Gaussian filtering is used to smooth and denoise the ultrasonic signal transmitted and received by the ultrasonic probe, and the frequencies corresponding to the ultrasonic signal at the time of transmission, the first transmission, and the second reflection are obtained respectively; According to the frequency change of the ultrasonic signal before and after emission and reflection, and in combination with the vibration degree of the reflector bracket when the ultrasonic probe emits the ultrasonic signal, the inclination angle of the reflector is adjusted to obtain the actual inclination angle of any reflector.

6. The hydrological information prediction method for water conservancy projects according to claim 1 is characterized in that: The specific method of calculating the actual reflection distance of any reflector in combination with the actual inclination angle of any reflector and based on the geometric principle of triangles includes: The specific calculation method of the actual reflection distance of any reflector is: in, Indicates that the ultrasound probe is The actual reflection distance of the reflector when the ultrasonic signal is emitted for the first time; Indicates the length of the reflector; Indicates that the ultrasound probe is The actual inclination angle of the reflector when the ultrasonic signal is emitted for the first time; Represents the cosine function.

7. The hydrological information prediction method for water conservancy projects according to claim 1 is characterized in that: The specific method of calculating the ultrasonic initial velocity and the attenuation rate of the ultrasonic signal at the ultrasonic probe according to the actual reflection distance of the two reflectors and the time for the ultrasonic probe to transmit and receive the ultrasonic signal includes: The actual reflection distances of the reflector 1 and the reflector 2 are obtained respectively, and half of the time from when the ultrasonic probe transmits the ultrasonic signal to when it receives the ultrasonic signal for the first time is recorded as the first sound path time, and half of the time from when the ultrasonic probe transmits the ultrasonic signal to when it receives the ultrasonic signal for the second time is recorded as the second sound path time; The ultrasonic initial velocity at the ultrasonic probe and the attenuation rate of the ultrasonic signal are obtained by combining the first sound path time, the second sound path time, the actual reflection distances of the reflector 1 and the reflector 2, and the attenuation rate of the ultrasonic signal.

8. The hydrological information prediction method for water conservancy projects according to claim 1 is characterized in that: The method of combining the ultrasonic initial velocity at the ultrasonic probe, the attenuation rate of the ultrasonic signal and the time for the ultrasonic probe to receive the ultrasonic signal to obtain the height of the liquid level from the ultrasonic probe includes the following specific methods: The specific calculation method of the height of the liquid level from the ultrasonic probe is: in, Indicates that the ultrasound probe is The height of the liquid level from the ultrasonic probe when the ultrasonic signal is emitted for the first time; Indicates that the ultrasound probe is The initial ultrasonic velocity at the ultrasonic probe when the ultrasonic signal is emitted for the first time; Indicates the third sound path time; Indicates that the ultrasound probe is The attenuation rate of the ultrasonic signal when the ultrasonic signal is emitted for the first time.

9. The hydrological information prediction method for water conservancy projects according to claim 1, characterized in that: The specific method of predicting data by using a prediction algorithm based on the height of the liquid level from the ultrasonic probe when the ultrasonic probe emits an ultrasonic signal each time includes: The sequence formed by the height of the liquid level from the ultrasonic probe when the ultrasonic probe emits ultrasonic signals all times is obtained, which is recorded as the liquid level height sequence. The EMD-LSTM algorithm is used to predict the liquid level height sequence.

10. The hydrological information prediction method for water conservancy projects according to claim 3, characterized in that: After calculating the vibration degree of the reflector bracket, the vibration degree is normalized using a sigmoid function.

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