A multi-modal based ultrasonic flow fusion method and system

Abstract

The present invention belongs to the technical field of flow detection, and specifically relates to a multi-modal ultrasonic flow fusion method and system. The method includes the following steps: S100, pre-constructing a modal number selection model; S200, respectively using a first probe and a second probe to send a first transmission signal and a second transmission signal, and correspondingly collecting a first received signal and a second received signal; S201, matching a corresponding modal selection number in the modal number selection model; S202, selecting at least three modes from the modes according to the modal selection number, and dividing the selected at least three modes into at least two modal groups; S203, calculating the volumetric flow rate according to the modal group; S205, calculating a flow mean value according to at least two of the volumetric flow rates. Compared with measuring the flow rate in a single mode, the present application greatly improves the measurement accuracy of the flow rate in a large-diameter scenario.

Description

[0001] Priority Application

[0002] This application claims the priority of the Chinese invention patent application 【2024118795026】 “

A Multimodal-based Ultrasonic Flow Fusion Method and System

[0003] The present invention belongs to the technical field of flow detection, and particularly relates to a multimodal-based ultrasonic flow fusion method and system. Background Art

[0004] In the field of ultrasonic flowmeter measurement, the flowmeters used in natural gas metering applications in China still mainly rely on imports from abroad. Ultrasonic flowmeters abroad have been developed earlier, and there are multiple brands widely used in on-site metering in the field of natural gas metering. Their measurement accuracy and functional perfection are very high. However, the prices of foreign-brand ultrasonic flowmeters are extremely high. The research on domestic ultrasonic flowmeters started relatively late. Due to the advantages of ultrasonic flowmeters in natural gas metering and market demand, currently, the research on domestic ultrasonic flowmeters is also developing rapidly, and the number of researchers is increasing, which has promoted the localization of ultrasonic flowmeters.

[0005] With the continuous iteration of ultrasonic flowmeters, it has been found that since the speed of ultrasonic wave propagation (sound speed) in the medium changes with temperature, temperature also has a great impact on the accuracy of flow measurement results. For this reason, the Chinese invention patent with the publication number CN101464171B discloses an ultrasonic flow detection system and detection method, which particularly relates to a high-precision fluid flow ultrasonic detection system and detection method. This method uses an improved time-difference method to calculate the velocity of the fluid; adopts a delayed window reception technique to reduce the influence of noise on the detection accuracy during detection through pulse width detection; and uses an interpolation correlation method and a correlation coefficient judgment method to further improve the resolution of the system's measurement time, reaching 1.25 ns, thereby significantly improving the accuracy and precision of the ultrasonic flowmeter and effectively avoiding the adverse impact of temperature on the flow measurement results.

[0006] However, although the above device has certain applicability, its application scenarios are greatly limited.

[0007] Therefore, there is an urgent need for a method that can improve the accuracy of flow measurement. Summary of the Invention

[0008] The purpose of the present invention is to provide a multimodal-based ultrasonic flow fusion method and system to improve the measurement accuracy of flow in large-diameter scenarios.

[0009] To solve the above-mentioned technical problems, the present invention specifically adopts the following technical solutions:

[0010] In a first aspect of the present invention, there is provided a multi-modal ultrasonic flow fusion method, comprising the following steps:

[0011] S200, respectively using a first probe and a second probe to send a first transmission signal and a second transmission signal, and correspondingly collecting a first received signal and a second received signal; wherein, during the propagation process of the first transmission signal or the second transmission signal in the system to be measured, at least three modes are generated, and the first received signal or the second received signal includes the received signals in the at least three modes;

[0012] S201, selecting at least three modes from the modes generated in S200;

[0013] S202, dividing the at least three modes selected in S201 into at least two mode groups, wherein one of the mode groups includes two modes;

[0014] S203, respectively defining the two modes in the mode group as a first mode and a second mode; respectively obtaining a first downstream propagation time and a first upstream propagation time in the first mode, and a second downstream propagation time and a second upstream propagation time in the second mode through the received signals, and calculating the volumetric flow rate in the mode group by using the following model;

[0015] Wherein, ;

[0016]

[0017] ;

[0018] In the formula, is the volumetric flow rate, is the first downstream propagation time, is the first upstream propagation time, is the second downstream propagation time, is the second upstream propagation time, is the first coefficient, is the second coefficient, is the third coefficient, is the fluid flow velocity, is the distance between the first probe and the second probe, is the pipe radius in the system to be measured;

[0019] S205, calculating the flow rate mean value according to at least two of the volumetric flow rates.

[0020] As an improvement, before S205, it further includes the step of:

[0021] S204, correcting the volume flow rate, and the correction method is to multiply the volume flow rate by a pre-obtained calibration coefficient.

[0022] As an improvement, in S204, the method for obtaining the calibration coefficient includes:

[0023] S41, conducting a preliminary experiment under experimental conditions to respectively obtain the actual flow rate results and calculated flow rate results of the current modal group within the calibration region under the experimental conditions; and the calculated flow rate results ; wherein, the calibration region is the region corresponding to at least two of the multiple modes obtained through the preliminary experiment;

[0024] S42, calculating the calibration coefficient according to the actual flow rate results and the calculated flow rate results ; ;

[0025] .

[0026] As an improvement, when obtaining the calibration coefficient, it further includes the step of:

[0027] S43, repeating the preliminary experiment under different experimental conditions to obtain calibration coefficients under different experimental conditions, and the experimental conditions at least include the number of modes;

[0028] Correspondingly, in S204, before correcting the volume flow rate, it further includes:

[0029] Obtaining the current condition, and matching the current condition with the experimental conditions to obtain the calibration coefficient matched under the current condition.

[0030] As an improvement, in S204, before correcting the volume flow rate, it further includes the step of:

[0031] S206, obtaining the current condition, and matching the current condition with the experimental conditions, and its specific steps include:

[0032] S61, obtaining at least three groups of received signals of at least three modes within the calibration region under the current condition, and at least three groups of standard received signals measured under at least three modes within the calibration region under the experimental conditions;

[0033] S62, respectively calculating the amplitude differences between the received signals and the standard received signals to obtain at least three amplitude differences;

[0034] S63. Determine whether all of the at least three amplitude differences are less than a first preset difference. If so, match the current condition with the experimental condition.

[0035] S207. Obtain the calibration coefficient under the experimental condition.

[0036] As an improvement, in S201, the specific steps of selecting at least three modes include: determining whether the current mode meets the selection condition, where the selection condition requires that the amplitude of the received signal in the current mode is greater than a first preset amplitude threshold, and / or the signal length of the received signal in the current mode conforms to a first preset length threshold range; if so, select the mode, otherwise do not select the mode.

[0037] Another aspect of the present invention is to provide a multi-modal ultrasonic flow fusion system, including:

[0038] A second acquisition module: configured to respectively transmit a first transmission signal and a second transmission signal using a first probe and a second probe, and correspondingly acquire a first received signal and a second received signal; wherein, at least three modes are generated during the propagation of the first transmission signal or the second transmission signal in the system to be measured, and the first received signal or the second received signal includes the received signals in the at least three modes.

[0039] A second mode selection module: configured to select at least three modes from the modes acquired by the second acquisition module.

[0040] A mode group division module: configured to divide the at least three modes selected by the second mode selection module into at least two mode groups, where one mode group includes two modes.

[0041] A data acquisition module: configured to respectively define the two modes in the mode group as a first mode and a second mode; and respectively obtain a first downstream propagation time and a first upstream propagation time in the first mode, and a second downstream propagation time and a second upstream propagation time in the second mode through the received signals.

[0042] A second calculation module: configured to calculate the volume flow rate under the mode group using the following model; and calculate the flow rate mean according to at least two of the volume flow rates.

[0043] Wherein, ;

[0044]

[0045] ;

[0046] In the formula, is the volumetric flow rate, is the first downstream propagation time, is the first upstream propagation time, is the second downstream propagation time, is the second upstream propagation time, is the first coefficient, is the second coefficient, is the third coefficient, is the fluid flow velocity, is the distance between the first probe and the second probe, is the pipe radius in the system to be measured.

[0047] As an improvement, it further includes:

[0048] A second correction module: configured to correct the volumetric flow rate, and the correction method is to multiply the volumetric flow rate by a pre-obtained calibration coefficient.

[0049] As an improvement, when the second correction module obtains the calibration coefficient, it is specifically configured to:

[0050] Conduct a preliminary experiment under experimental conditions to respectively obtain the actual flow rate results of the current mode group in the calibration area under the experimental conditions and the calculated flow rate results ; wherein, the calibration area is the area corresponding to at least two modes among the multiple modes obtained through the preliminary experiment;

[0051] According to the actual flow rate results and the calculated flow rate results Calculate to obtain the calibration coefficient ; wherein,

[0052] .

[0053] As an improvement, when the second correction module obtains the calibration coefficient, it is further configured to repeat the preliminary experiment under different experimental conditions to obtain calibration coefficients under different experimental conditions, and the experimental conditions at least include the number of modes; correspondingly, before the second correction module corrects the volumetric flow rate, it is further configured to obtain the current condition and match the experimental conditions according to the current condition to obtain the calibration coefficient matched under the current condition.

[0054] The principle and beneficial technical effects of the present invention are as follows:

[0055] In large-diameter pipelines, due to the relatively high flow velocity, the kinetic energy of the fluid is relatively large, resulting in an increase in the amplitude of fluid flow fluctuations. When the flow velocity increases, the disturbance of the fluid to ultrasonic waves also increases, which will lead to a large error in the measurement of the propagation time of ultrasonic signals. This error will be amplified during the subsequent calculation process. Therefore, the error of the volume flow rate calculated based on time will also increase significantly.

[0056] In view of the above scenarios of large-diameter pipelines and high flow velocities, the present application compensates for the error by using the time difference of ultrasonic wave transmission between finite modes (bimodal) under a finite mode group. By measuring the time differences of downstream and upstream flows between two different modes (which includes the time differences of downstream and upstream flows in the first mode, the time differences of downstream and upstream flows in the second mode, and the multi-dimensional time differences of cross-downstream and upstream flows between the first mode and the second mode), and using the multi-dimensional time difference information to compensate for the error measured in a single mode; and correcting and fusing the obtained finite individual volume flow rate data, and then obtaining the compensated and corrected comprehensive volume flow rate, which greatly improves the accuracy of flow measurement in large-diameter pipelines.

[0057] First of all, the present application provides a mechanism for collecting modal data with high strength and wide amplitude, which double-restricts the amplitude and the length of the collected signal, and selects the two most representative modes. On the one hand, the mode with a larger amplitude can retain the integrity of the original signal to the greatest extent and reduce the interference of other factors (such as noise); on the other hand, by restricting the signal length and selecting the mode of the received signal with a larger signal length within the preset length threshold range, a wider data collection window can be divided under this mode, and then more data point information can be obtained. Furthermore, using multiple data point information as the original data to calculate a more accurate downstream and upstream flow time, thereby improving the accuracy of flow measurement without excessively increasing the amount of data collection and signal processing.

[0058] Furthermore, the present application adaptively selects a finite number of modes that match the total number of current ultrasonic modes, divides the selected finite number of modes into finite mode groups, calculates the flow rate separately, and finally corrects and integrates multiple flow rate results, which greatly improves the measurement accuracy of the volume flow rate.

[0059] Among them, during the correction process, corresponding calibration coefficients are determined respectively for different experimental conditions (such as different numbers of modes), which can enable matching the specified calibration coefficient of the current mode during the measurement of the volume flow rate, further improving the accuracy; furthermore, before matching the calibration coefficient, by preliminarily screening the current conditions, for example, limiting the signal length and amplitude within the calibration region, more reliable calibration coefficients are selected, which can effectively avoid problems such as inaccurate received signals (modes) caused by unstable excitation signals or other accidental factors. Brief Description of the Drawings

[0060] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale. Obviously, the following-described drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0061] Figure 1 It is a schematic diagram of the measurement principle of the flowmeter in the embodiment of the present invention;

[0062] Figure 2 It is a schematic diagram of the signal characteristics of the ultrasonic flowmeter in the embodiment of the present invention;

[0063] Figure 3 It is a flowchart of the ultrasonic flow measurement method with temperature adaptation in the embodiment of the present invention;

[0064] Figure 4 It is a modular schematic diagram of the ultrasonic flow measurement system with temperature adaptation in the embodiment of the present invention;

[0065] Figure 5 It is a flowchart of the ultrasonic flow fusion method based on multi-modal in the embodiment of the present invention;

[0066] Figure 6 It is a modular schematic diagram of the ultrasonic flow fusion system based on multi-modal in the embodiment of the present invention;

[0067] Figure 7 It is a schematic diagram of the forward and reverse flow acoustic wave fluctuation amplitudes in the first mode of Simulation Experiment 1;

[0068] Figure 8 It is a schematic diagram of the forward and reverse flow acoustic wave fluctuation amplitudes in the second mode of Simulation Experiment 1;

[0069] Figure 9 It is a comparison chart of the flow rate change rates in Simulation Experiment 1;

[0070] Figure 10 It is a schematic diagram of the forward and reverse flow acoustic wave fluctuation amplitudes in the first mode of Simulation Experiment 2;

[0071] Figure 11 It is a schematic diagram of the forward and reverse flow acoustic wave fluctuation amplitudes in the second mode of Simulation Experiment 2;

[0072] Figure 12 It is a comparison chart of the flow rate change rates in Simulation Experiment 2. Detailed Implementation Modes

[0073] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0074] In this article, suffixes such as "module", "component" or "unit" used to represent elements are only for the convenience of describing the present invention, and they have no specific meaning in themselves. Therefore, "module", "component" or "unit" can be used interchangeably. In this article, the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "outer", "front", "rear", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0075] In this article, unless otherwise clearly specified and defined, terms such as "installation", "provided with", "connection", etc. shall be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In this article, "a plurality" means two or more, that is, it includes two, three, four, five, etc.

[0076] In the prior art, the ultrasonic measurement principle is as Figure 1 shown. In the ultrasonic probe (mainly including a piezoelectric ceramic sheet and a wedge), the piezoelectric ceramic is connected to the pipe wall through the wedge, and the acoustic wave propagation path can be extended by changing the position of the wedge.

[0077] The angle between the normal direction of the piezoelectric ceramic sheet and the normal direction of the pipe wall is , the thickness of the pipe wall is , the distance between the wedge blocks is , and the piezoelectric ceramic sheet is in the pipe axis plane. The measured pipe radius is . Considering that the pipe wall and the ultrasonic wedge material are the same, the ultrasonic wave propagates at the same speed in the wedge and the pipe wall without angle change. On the inner wall of the pipe, due to the inconsistent acoustic wave propagation speeds in different media, the refraction angle Let the sound wave propagation speeds in the pipe wall and the fluid be respectively and . Then the refraction angle satisfies Snell's law, that is:

[0078] (1)

[0079] The electrical signal generates an ultrasonic mechanical signal by exciting the piezoelectric ceramic 1. The ultrasonic signal is refracted at the pipe wall and enters the propellant, and propagates along the flow direction. After reaching the piezoelectric ceramic 2, it makes the piezoelectric ceramic generate a piezoelectric signal to form an electrical signal. A propagation time difference is generated between the two signals, denoted as the downstream time . On the other hand, when the ultrasonic wave generated by exciting the piezoelectric ceramic 2 by the electrical signal propagates in the opposite direction to the flow direction, an upstream time is formed

[0080] In the pipe flow, the flow field formed by the fluid flow is relatively complex. For the convenience of modeling, it is assumed that the fluid flow field is a uniform flow field ( ). Without considering the propagation time of the sound wave in the acoustic wedge and the pipe wall, then Figure 1 The corresponding upstream and downstream propagation times are

[0081] (2)

[0082] Then there is

[0083] (3)

[0084] At the same time

[0085] (4)

[0086] Substituting formula (4) into formula (3) can obtain

[0087] (5)

[0088] Then the volume flow rate can be expressed as

[0089] (6)

[0090] Similarly, substituting formula (5) into formula (4) can obtain the sound speed

[0091] (7)

[0092] Furthermore, from formula (1), it can be obtained that is related to the sound wave propagation speed in the fluid. Then substituting formula (1) into the above formula can obtain

[0093] (8)

[0094] In the above formula, represents the sound wave propagation velocity in the solid. When the sound velocity in the fluid is known and the fluid pressure changes little, there is a corresponding relationship between the sound velocity and the temperature, and thus the fluid temperature can be obtained, and then the fluid density can be obtained.

[0095] Furthermore, the volume flow rate can be expressed as

[0096] (9)

[0097] It is not difficult to see that and The pipe radius is fixed at the design stage and will not change. The sound velocity in the pipe wall is affected by temperature, and a temperature compensation experiment needs to be carried out for compensation.

[0098] When a continuous wave is adopted, assuming that the frequency of the acoustic wave signal is , then the time ( ) and the phase ( ) have the following formula

[0099] (10)

[0100] Substituting the above formula into formula (8) can obtain the sound velocity in the fluid as

[0101] (11)

[0102] Among them, is the countercurrent phase, is the downstream phase;

[0103] Substituting the above formula into formula (9) can obtain the volume flow rate formula

[0104] (12)

[0105] It can be seen from the formula that whether it is the volume measurement based on time (formula (9)) or the volume measurement based on phase (formula (12)), there is the sound wave propagation velocity given as a parameter. This parameter changes with different temperatures.

[0106] Example 1

[0107] In order to eliminate the influence of temperature on the volume flow rate measurement, the present invention provides a temperature-adaptive ultrasonic flow measurement method. Refer to Figure 3 , which includes the following steps:

[0108] S101, respectively use a first probe and a second probe to transmit a first transmission signal and a second transmission signal, and correspondingly collect a first received signal and a second received signal; wherein, during the propagation process of the first transmission signal or the second transmission signal in the system to be measured, multiple modes are generated, and the first received signal or the second received signal includes the received signals in the multiple modes;

[0109] S102, select two modes from the multiple modes, and respectively define the two selected modes as a first mode and a second mode;

[0110] S103, respectively obtain a first downstream propagation time and a first upstream propagation time in the first mode, and a second downstream propagation time and a second upstream propagation time in the second mode through the received signals;

[0111] S104, according to the first downstream propagation time, the first upstream propagation time, the second downstream propagation time, and the second upstream propagation time, calculate the volumetric flow rate using the following model:

[0112] ;

[0113]

[0114] ;

[0115] In the formula, is the volumetric flow rate, is the first downstream propagation time, is the first upstream propagation time, is the second downstream propagation time, is the second upstream propagation time, is the first coefficient, is the second coefficient, is the third coefficient, is the fluid flow velocity, is the distance between the first probe and the second probe, is the pipe radius of the system to be measured.

[0116] Among them, when , it indicates that the fluid in the pipe is flowing forward, and at this time

[0117]

[0118] When , it indicates that the fluid in the pipe is flowing backward, and at this time

[0119]

[0120] Among them, the device for obtaining modal information in S101 can refer to the inventor's prior patent (CN115493662B, integrated ultrasonic flowmeter and system for aerospace); the acquisition of relevant parameters of multiple modes can refer to the patent (CN119023015A, multi-modal ultrasonic fluid multi-parameter measurement device and method).

[0121] In some embodiments, in S102, the specific steps of selecting the mode include:

[0122] S1021, determine whether the current mode meets the selection conditions. The selection conditions require that the amplitude of the received signal in the current mode is greater than a first preset amplitude threshold, and / or the signal length of the received signal in the current mode conforms to a first preset length threshold range; if so, classify the mode into the optional mode set. That is, determine whether the amplitude of the received signal in the current mode is greater than the first preset amplitude threshold, and / or determine whether the signal length of the received signal in the current mode conforms to the first preset length threshold range. If at least one of the above conditions is met (including the following three cases: 1. The amplitude of the received signal in the current mode is greater than the first preset amplitude threshold, but the signal length of the received signal in the current mode does not conform to the first preset length threshold range; 2. The amplitude of the received signal in the current mode is less than the first preset amplitude threshold, but the signal length of the received signal in the current mode conforms to the first preset length threshold range; 3. The amplitude of the received signal in the current mode is greater than the first preset amplitude threshold, and the signal length of the received signal in the current mode conforms to the first preset length threshold range), then classify the mode into the optional mode set.

[0123] S1023, select two modes from the optional mode set, and define the two modes as the first mode and the second mode respectively.

[0124] This application provides a high-strength and wide-amplitude modal data acquisition mechanism to directly improve the accuracy of flow measurement from the data source.

[0125] Among them, referring to Figure 2 , the amplitude refers to the intensity of the received signal corresponding to each mode. The greater the intensity of the received signal, the greater its amplitude; the signal length refers to the width of the signal received corresponding to each mode. For example, the signal length corresponding to mode 3 is X. In this application, the number of cycles of the excitation signal is limited to about 60. Within the corresponding signal length range, the number of sampling points is 1024. By limiting the number of cycles of the excitation signal, both the data acquisition volume is ensured, and the difficulty of data processing is not overly increased, avoiding the problem that an overly large excitation signal leads to an overly long acquisition signal, and thus an overly long acquisition signal length will cause an increase in data acquisition and processing volume.

[0126] Among them, the signal length refers to the actual time span from the start to the end of the signal, usually measured in seconds (s); the number of sampling points represents the number of samples of the signal at discrete time points.

[0127] In this application, by imposing double restrictions on the amplitude of the mode and the signal length, key modes are selected for calculation, which can directly improve the accuracy of flow measurement from the data source. Specifically, modes with larger amplitudes are usually less affected by interference during transmission and are more accurate; and when the signal length of the received signal is larger, a wider data acquisition window can be divided in this mode, thereby obtaining more data point information (that is, the sampled point data selected from the received signal, and the data can include the acquisition time and / or amplitude), and then using the Fourier transform method to calculate a more accurate upstream and downstream time from multiple data point information. Among them, the specific steps of calculating the upstream and downstream time using the Fourier transform method can be referred to in the Chinese invention patent with the publication number CN119023014A, for the steps of calculating the downstream delay time (equivalent to the downstream propagation time in this article) and the upstream delay time (equivalent to the upstream propagation time in this article).

[0128] In some embodiments, S1021 further includes determining whether the duration of the current excitation signal is greater than a first preset time threshold; when the duration of the excitation signal is longer, usually enough modes can be generated, and key modes are selected from these modes for data acquisition, which is more representative and the measured data is more accurate.

[0129] In some embodiments, S1021 further includes determining whether the amplitude of the received signal in the current mode is less than a second preset amplitude threshold, and if so, classifying the mode into the optional mode set.

[0130] See Figure 2, under different modes, different amplitudes and durations are collected correspondingly; in this article, the first preset amplitude threshold can be a specific amplitude determined by the user based on multiple amplitudes of multiple modes under different experimental conditions obtained through preliminary experiments, but at the same time, this amplitude should be lower than the safe amplitude value (when the sound wave amplitude is too large, it may cause damage to the device. Therefore, the safe amplitude value refers to the maximum amplitude value that will not cause damage to the device); correspondingly, the second preset amplitude threshold can be an amplitude value between the first preset amplitude threshold and the safe amplitude value; correspondingly, the first preset length threshold range can be a specific signal length threshold range determined by the user based on multiple signal lengths of multiple modes under different experimental conditions obtained through preliminary experiments. The signal length within this range can ensure that the received signal of the mode can be collected as much as possible, but will not collect too many invalid signals; the first preset time threshold can be a specific time value determined by the user based on multiple durations of multiple modes under different experimental conditions obtained through preliminary experiments.

[0131] In some embodiments, before S1023, it further includes the step: S1022, determining whether the number of modes in the optional mode set is greater than or equal to two. If so, execute S1023; otherwise, adjust the first preset amplitude threshold according to the first decrement until the number of modes meets the requirement of being greater than or equal to two.

[0132] That is to say, the first preset amplitude threshold can also be adjusted according to the actual situation to ensure that the number of modes in the optional mode set is greater than or equal to two.

[0133] In some embodiments, in step S1023, the specific steps of selecting two modes from the optional mode set include: when the number of modes is greater than two, selecting the mode with the largest amplitude of the received signal as the first mode, and selecting the mode with the amplitude closest to the first amplitude of the first mode as the second mode.

[0134] In some embodiments, it further includes the step:

[0135] S105, correcting the volume flow rate obtained in S104 by using a preset correction rule, and the correction rule is to multiply the volume flow rate by a previously obtained calibration coefficient.

[0136] In some embodiments, the calibration coefficient is obtained in the following manner:

[0137] Conduct preliminary experiments under experimental conditions to obtain the actual flow rate results of the modes within the calibration area of the current pipeline (measurement system) under experimental conditions and the calculated flow rate results ; wherein, the calibration region is a region corresponding to at least two of the multiple modalities obtained through the preliminary experiment;

[0138] According to the actual flow result and the calculated flow result calculate the calibration coefficient ;

[0139] ;

[0140] wherein, the calculated flow result is calculated by using the above steps S101 - S104; the actual flow result can be directly obtained by presetting the volume flow rate of the fluid in the injection pipeline.

[0141] In some embodiments, when determining the calibration coefficient, it further includes the step: under different experimental conditions, repeat the preliminary experiment to obtain the calibration coefficients under different experimental conditions, and the experimental conditions at least include the number of modalities;

[0142] Correspondingly, in S105, before correcting the volume flow rate, it further includes: obtaining the current condition, and matching the current condition with the experimental conditions to obtain the calibration coefficient matched under the current condition.

[0143] In some embodiments, the specific steps of matching the current condition with the experimental conditions include:

[0144] S51, obtain at least two groups of received signals (also called amplitude signals) of at least two modalities within the calibration region under the current condition, and at least two groups of standard received signals measured under at least two modalities within the calibration region under the experimental conditions;

[0145] S52, calculate the amplitude differences between the at least two groups of received signals and the at least two groups of standard received signals respectively to obtain at least two amplitude differences;

[0146] S53, determine whether at least two of the amplitude differences are all less than the first preset difference. If so, match the current condition with the experimental conditions.

[0147] In some embodiments, the specific steps of matching the current condition with the experimental conditions include:

[0148] S54, obtain the received signals of at least two modalities within the calibration region under the current condition;

[0149] S55, determine whether the signal lengths in the received signals all meet the first preset length threshold range. If so, match the current condition with the experimental conditions.

[0150] It should be noted that when matching the experimental conditions according to the current conditions, it is possible to select only one of the amplitude or the signal length for matching, or to select both the amplitude and the signal length for matching. And when there is no match, the amplitude and / or the signal length can be re-measured for matching, or the excitation conditions can be adjusted or other methods can be adopted to re-obtain the amplitude and / or the signal length for matching.

[0151] To verify the reliability of this solution, the following verification experiments were carried out. Among them, verification experiment 1 (see Figures 7 - 9 ) was obtained by conducting a verification experiment at an ambient temperature of -14°C and a temperature of the medium in the pipe of -16°C. Among them, Figure 7 and Figure 8 are schematic diagrams showing the variation of the upstream and downstream acoustic wave amplitudes with time in the first mode (mode 1) and the second mode (mode 2). According to Figure 7 and Figure 8 the data in, a schematic diagram of the flow rate change of this ultrasonic flowmeter was drawn, and the flow rate change data directly measured by a standard mass flowmeter was introduced to obtain Figure 9 the flow rate change comparison diagram shown. It can be seen that the flow rate measured by adopting this solution is basically the same as the standard data under ideal conditions measured by the mass flowmeter, which also confirms the reliability of this solution.

[0152] To further confirm the accuracy of this solution, the above experiment (verification experiment 2) was carried out again in this application at an ambient temperature of -13°C and a temperature of the medium in the pipe of -15.8°C. For details, see Figures 10 - 12 , and it can be found that under this condition, the flow rate measured by adopting this solution is also very close to the standard data measured by the standard mass flowmeter, which further confirms the reliability of this solution.

[0153] Thus, it can be seen that the above representation method of the volumetric flow rate does not consider the acoustic wave propagation speed, thereby realizing temperature self-adaptation.

[0154] In summary, the present invention compensates for this error based on the ultrasonic wave transmission time difference between finite modes (bimodes), and comprehensively provides a temperature self-adaptive flow measurement method with higher accuracy, which is especially suitable for the measurement of large-diameter flow rates.

[0155] Furthermore, the present application provides a high-strength and wide-range modal data acquisition mechanism that double-restricts the amplitude and signal length, and selects the two most representative modes. On the one hand, the mode with a larger amplitude can retain the integrity of the original signal to the greatest extent and reduce the interference of other factors (such as noise). On the other hand, by restricting the signal length, selecting the mode of the received signal with a larger signal length within the preset length threshold range can divide a wider data acquisition window in this mode, thereby obtaining more data point information. Then, using multiple data point information as the original data to calculate a more accurate upstream and downstream time, and further improving the accuracy of flow measurement without overly increasing the data acquisition and processing volume.

[0156] Furthermore, the present invention corrects the measured flow rate result, which can further compensate for the errors caused by condition differences (such as different numbers of modes excited by ultrasonic signals with different periods), and further improves the accuracy of flow measurement. During the correction process, for different experimental conditions (such as different numbers of modes), the corresponding calibration coefficients are measured respectively, which can make the specified calibration coefficient of this mode be matched according to the current mode during the measurement of volumetric flow rate, further improving the accuracy. In addition, before matching the calibration coefficient, by preliminarily screening the current conditions, for example, limiting the acquisition signal length and amplitude in the calibration area, and selecting a more reliable calibration coefficient, it can effectively avoid the problem of inaccurate received signal (mode) caused by, for example, unstable excitation signal or other accidental factors.

[0157] Embodiment 2

[0158] See Figure 4 , the present invention provides a temperature-adaptive ultrasonic flow measurement system, including:

[0159] The first acquisition module: configured to respectively use the first probe and the second probe to send the first transmission signal and the second transmission signal, and correspondingly acquire the first received signal and the second received signal; wherein, during the propagation process of the first transmission signal or the second transmission signal in the system to be measured, multiple modes are generated, and the first received signal or the second received signal includes the received signals in the multiple modes;

[0160] The first mode selection module: configured to select two modes from the multiple modes, and the two modes are respectively defined as the first mode and the second mode;

[0161] The time acquisition module: configured to respectively obtain the first downstream propagation time and the first upstream propagation time in the first mode, and the second downstream propagation time and the second upstream propagation time in the second mode through the received signals;

[0162] The first calculation module: configured to calculate the volumetric flow rate according to the first downstream propagation time, the first upstream propagation time, the second downstream propagation time, and the second upstream propagation time, using the following model:

[0163] ;

[0164]

[0165] ;

[0166] wherein, is the volumetric flow rate, is the first downstream propagation time, is the first upstream propagation time, is the second downstream propagation time, is the second upstream propagation time, is the first coefficient, is the second coefficient, is the third coefficient, is the fluid flow velocity, is the distance between the first probe and the second probe, is the pipe radius of the system to be measured.

[0167] wherein, when it indicates that the fluid in the pipe is flowing forward, and at this time

[0168]

[0169] When it indicates that the fluid in the pipe is flowing backward, and at this time

[0170]

[0171] In some embodiments, the first mode selection module is specifically configured to determine whether the current mode meets the selection conditions. The selection conditions require that the amplitude of the received signal in the current mode is greater than a first preset amplitude threshold, and / or the signal length of the received signal in the current mode conforms to a first preset length threshold range; if so, the mode is classified into the set of selectable modes; and two modes are selected from the set of selectable modes and defined as the first mode and the second mode respectively.

[0172] In some embodiments, it further includes:

[0173] The mode number judgment module: configured to judge whether the number of modes in the set of selectable modes is greater than or equal to two;

[0174] Adjustment module: Configured to adjust the first preset amplitude threshold according to a first decrement when the number of modes in the set of optional modes is less than two until the number of modes meets the condition of being greater than or equal to two.

[0175] In some embodiments, the first mode selection module is specifically configured to: when the number of modes is greater than two, select the mode with the largest amplitude of the received signal as the first mode, and select the mode with the amplitude of the received signal closest to the first amplitude of the first mode as the second mode.

[0176] In some embodiments, it further includes: a first correction module: configured to correct the volume flow rate calculated by the first calculation module using a preset correction rule, and the correction rule is to multiply the volume flow rate by a pre-obtained calibration coefficient.

[0177] Wherein, the calibration coefficient is obtained in the following manner:

[0178] Perform a preliminary experiment under experimental conditions to obtain the actual flow rate result of the current pipeline under experimental conditions and the calculated flow rate result ;

[0179] According to the actual flow rate result and the calculated flow rate result calculate the calibration coefficient ;

[0180] ;

[0181] Wherein, the calculated flow rate result is calculated using the above first calculation module; the actual flow rate result can be directly obtained by presetting the volume flow rate of the fluid injected into the pipeline.

[0182] In some embodiments, when determining the calibration coefficient, it further includes the step of: repeating the preliminary experiment under different experimental conditions to obtain calibration coefficients under different experimental conditions, and the experimental conditions at least include the number of modes;

[0183] Correspondingly, before correcting the volume flow rate, it further includes:

[0184] Obtain the current condition, and match the experimental conditions according to the current condition to obtain the calibration coefficient matched under the current condition.

[0185] Embodiment III

[0186] See Figure 5, the present invention provides a multi-modal based ultrasonic flow fusion method, including the following steps:

[0187] S200, respectively use a first probe and a second probe to send a first transmission signal and a second transmission signal, and correspondingly collect a first received signal and a second received signal; wherein, at least three modes are generated during the propagation process of the first transmission signal or the second transmission signal in the system to be measured, and the first received signal or the second received signal includes the received signals in the at least three modes;

[0188] Specifically, when one of the probes sends a sine pulse beam (a beam composed of multiple periods), that is, the transmission signal, the corresponding other probe receives 6 ultrasonic modes with different propagation speeds (such as Figure 2 mode 1, mode 2... mode 6 in

[0189] S201, select at least three modes from the modes generated in S200;

[0190] S202, divide the at least three modes selected in S201 into at least two mode groups, wherein one of the mode groups includes two modes;

[0191] S203, respectively define the two modes in the mode group as a first mode and a second mode; respectively obtain a first downstream propagation time and a first upstream propagation time in the first mode, and a second downstream propagation time and a second upstream propagation time in the second mode through the received signals, and calculate the volumetric flow rate in the mode group by using the following model;

[0192] Wherein, ;

[0193]

[0194] ;

[0195] In the formula, is the volumetric flow rate, is the first downstream propagation time, is the first upstream propagation time, is the second downstream propagation time, is the second upstream propagation time, is the first coefficient, is the second coefficient, is the third coefficient, is the fluid flow velocity, is the distance between the first probe and the second probe, is the pipe radius in the system to be measured;

[0196] S205. Calculate the flow rate average value based on at least two of the volume flow rates.

[0197] In some embodiments, before S200, the method further includes the step of:

[0198] S100. Pre-build a modal number selection model. The step of pre-building the modal number selection model includes setting at least two modal number ranges and respectively matching corresponding modal selection numbers for the at least two modal number ranges;

[0199] Correspondingly, in S200, respectively use the first probe and the second probe to send a first transmission signal and a second transmission signal, and respectively collect a first received signal and a second received signal; wherein, at least three modes are generated during the propagation process of the first transmission signal or the second transmission signal in the system to be measured, and the first received signal or the second received signal includes the received signals in the at least three modes;

[0200] S201. According to the number of the modes generated in S200, match the corresponding modal selection number in the modal number selection model. The modal selection number is greater than or equal to three, and select at least three modes from the modes according to the modal selection number;

[0201] S202. Divide the at least three selected modes into at least two mode groups, wherein one of the mode groups includes two modes;

[0202] Among them, when dividing the modes into at least two mode groups, it can be determined according to the total number of modes and the selected modal selection number. For example, referring to Figure 2 , the figure shows the case where the total number of modes is 6. At this time, the total number of modes is relatively small, and three or four modes can be selected and divided into two mode groups; for another example, when the total number of modes is large (not shown in the figure), select a larger number of modes (preferably an even number of modes) and combine them in pairs into three or more mode groups.

[0203] S203. Define the two modes in the mode group as the first mode and the second mode respectively; respectively obtain the first downstream propagation time and the first upstream propagation time in the first mode, and the second downstream propagation time and the second upstream propagation time in the second mode through the received signals, and calculate the volume flow rate in the mode group by using the following formula;

[0204] Among them, ;

[0205]

[0206] ;

[0207] In the formula, is the volumetric flow rate, is the first downstream propagation time, is the first upstream propagation time, is the second downstream propagation time, is the second upstream propagation time, is the first coefficient, is the second coefficient, is the third coefficient, is the fluid flow velocity, is the distance between the first probe and the second probe, is the radius of the pipeline to be measured;

[0208] Wherein, when it indicates that the fluid in the pipeline is flowing in the forward direction. At this time

[0209]

[0210] When it indicates that the fluid in the pipeline is flowing in the reverse direction. At this time

[0211]

[0212] For different mode groups, S203 is respectively executed to obtain the volumetric flow rates corresponding to multiple mode groups.

[0213] It should be noted that the first coefficient , the second coefficient and the third coefficient in this article are only named for distinction and can be understood as representative characters. They are obtained by different calculation methods according to the first downstream propagation time, the first upstream propagation time, the second downstream propagation time and the second upstream propagation time, and have no actual meaning.

[0214] S205, calculate the flow rate average value according to the (multiple) said volumetric flow rates.

[0215] In some embodiments, before S205, it further includes the step of:

[0216] S204, correct the volumetric flow rate, and the correction method is to multiply the volumetric flow rate by a pre-obtained calibration coefficient.

[0217] In some embodiments, the method for obtaining the calibration coefficient includes:

[0218] S41. Conduct a preliminary experiment under experimental conditions to respectively obtain the actual flow rate results of the current mode group within the calibration region under the experimental conditions and the calculated flow rate results ; wherein, the calibration region is the region corresponding to at least two modes among the multiple modes obtained through the preliminary experiment;

[0219] S42. Calculate the calibration coefficient based on the actual flow rate results and the calculated flow rate results ; ;

[0220] ;

[0221] wherein, the calculated flow rate results are calculated using the above steps S100 - S203; the actual flow rate results can be directly obtained by presetting the volume flow rate of the fluid in the injection pipeline.

[0222] It should be noted that the calibration coefficient can be one or multiple. For example, when there is one mode group, there is only one calibration coefficient; when there are two mode groups, there are two calibration coefficients, corresponding to the two mode groups respectively, and so on; during the actual measurement process, match the mode selected in the mode group with the mode group corresponding to the calibration coefficient to obtain the calibration coefficient in the current mode group.

[0223] In some embodiments, when obtaining the calibration coefficient, it further includes the step of:

[0224] S43. Repeat the preliminary experiment under different experimental conditions to obtain calibration coefficients under different experimental conditions, and the experimental conditions at least include the number of modes;

[0225] Correspondingly, in S204, before correcting the volume flow rate, it further includes: obtaining the current condition and matching the current condition with the experimental conditions to obtain the calibration coefficient matched under the current condition.

[0226] In some embodiments, in S204, before correcting the volume flow rate, it further includes the step of:

[0227] S206. Obtain the current condition and match the current condition with the experimental conditions, and its specific steps include:

[0228] S61. Obtain at least three groups of received signals of at least three modes within the calibration region under the current condition, and at least three groups of standard received signals measured under at least three modes within the calibration region under the experimental conditions;

[0229] S62. Calculate the amplitude differences between the received signal and the standard received signal respectively to obtain at least three amplitude differences.

[0230] S63. Determine whether all of the at least three amplitude differences are less than a first preset difference. If so, match the current condition with the experimental condition.

[0231] S207. Obtain the calibration coefficient under the experimental condition.

[0232] In some embodiments, in S206, the specific steps of matching the experimental condition according to the current condition include:

[0233] S64. Obtain at least three sets of received signals of at least three modes within the calibration region under the current condition.

[0234] S65. Determine whether the signal lengths in the received signals all conform to a first preset length threshold range. If so, match the current condition with the experimental condition signal.

[0235] It should be noted that when matching the experimental condition according to the current condition, only one of the amplitude or the signal length can be selected for matching, or both the amplitude and the signal length can be selected for matching. And when there is no match, the amplitude and / or the signal length can be re-measured for matching, or the excitation condition can be adjusted or other methods can be adopted to re-obtain the amplitude and / or the signal length for matching.

[0236] In some embodiments, in S201, the specific steps of selecting at least three modes include: determining whether the current mode meets the selection condition, where the selection condition requires that the amplitude of the received signal in the current mode is greater than a first preset amplitude threshold, and / or the signal length of the received signal in the current mode conforms to a first preset length threshold range; if so, classify the mode into the optional mode set. That is, determine whether the amplitude of the received signal in the current mode is greater than a first preset amplitude threshold, and / or determine whether the signal length of the received signal in the current mode conforms to a first preset length threshold range. If at least one of the above conditions is met (including the following three cases: 1. The amplitude of the received signal in the current mode is greater than the first preset amplitude threshold, but the signal length of the received signal in the current mode does not conform to the first preset length threshold range; 2. The amplitude of the received signal in the current mode is less than the first preset amplitude threshold, but the signal length of the received signal in the current mode conforms to the first preset length threshold range; 3. The amplitude of the received signal in the current mode is greater than the first preset amplitude threshold, and the signal length of the received signal in the current mode conforms to the first preset length threshold range), then classify the mode into the optional mode set.

[0237] In some embodiments, the specific steps of selecting at least three modes from the modes according to the number of selected modes further include: determining whether the amplitude of the received signal in the current mode is less than a second preset amplitude threshold. If so, select the mode; otherwise, do not select the mode.

[0238] See Figure 2 , in different modes, different amplitudes and durations are correspondingly collected; in this article, the first preset amplitude threshold may be a specific amplitude determined by the user based on multiple amplitudes under different experimental conditions obtained through preliminary experiments. However, at the same time, this amplitude should be lower than the safe amplitude value (when the sound wave amplitude is too large, it may cause damage to the device. Therefore, the safe amplitude value refers to the maximum amplitude value that will not cause damage to the device); correspondingly, the second preset amplitude threshold may be an amplitude value between the first preset amplitude threshold and the safe amplitude value; correspondingly, the first preset length threshold range may be a specific signal length threshold range determined by the user based on multiple signal lengths under different experimental conditions obtained through preliminary experiments; the first preset time threshold may be a specific time value determined by the user based on multiple durations under different experimental conditions obtained through preliminary experiments.

[0239] In summary, for the above-mentioned scenarios of large pipe diameters and high flow rates, the present application compensates for errors through the time difference of ultrasonic wave transmission between finite modes (dual modes) in a finite mode group. By measuring the time differences of downstream and upstream flows between two different modes (which includes the time differences of downstream and upstream flows in the first mode, the time differences of downstream and upstream flows in the second mode, and the multi-dimensional time differences of cross-downstream and upstream flows between the first mode and the second mode), and using the multi-dimensional time difference information to compensate for the errors measured in a single mode; and correcting and fusing the obtained finite individual volume flow data, and then obtaining the compensated and corrected comprehensive volume flow, which greatly improves the accuracy of flow measurement in large pipe diameters.

[0240] First of all, the present application provides a high-strength and wide-amplitude mode data acquisition mechanism, which double-limits the amplitude and the length of the collected signal, and selects the two most representative modes. On the one hand, the mode with a larger amplitude can retain the integrity of the original signal to the greatest extent and reduce the interference of other factors (such as noise); on the other hand, by restricting the signal length and selecting the mode of the received signal with a larger signal length within the preset length threshold range, a wider data acquisition window can be divided in this mode, and then more data point information can be obtained. Furthermore, using multiple data point information as the original data to calculate a more accurate downstream and upstream time, thereby improving the accuracy of flow measurement without excessively increasing the data acquisition and processing volume of the signal.

[0241] Furthermore, according to the total number of current ultrasonic modes, the present application adaptively selects a finite number of modes that match this total number, divides the selected finite number of modes into finite mode groups, calculates the flow rate for each group separately, and finally corrects and integrates multiple flow rate results, greatly improving the measurement accuracy of the volumetric flow rate.

[0242] Among them, during the correction process, for different experimental conditions (such as different numbers of modes), the corresponding calibration coefficients are measured respectively, which can enable the matching of the specified calibration coefficient for the current mode during the measurement of the volumetric flow rate, further improving the accuracy; furthermore, before matching the calibration coefficient, by preliminarily screening the current conditions, for example, limiting the signal length and amplitude within the calibration area, more reliable calibration coefficients are selected, which can effectively avoid problems such as inaccurate received signals (modes) caused by unstable excitation signals or other accidental factors.

[0243] Embodiment 4

[0244] See Figure 6 , the present invention provides a multi-modal ultrasonic flow fusion system, including:

[0245] The second acquisition module: configured to respectively transmit a first transmission signal and a second transmission signal using a first probe and a second probe, and correspondingly acquire a first received signal and a second received signal; wherein, during the propagation process of the first transmission signal or the second transmission signal in the system to be measured, at least three modes are generated, and the first received signal or the second received signal includes the received signals in the at least three modes;

[0246] The second mode selection module: configured to select at least three modes from the modes acquired by the second acquisition module;

[0247] The mode group division module: configured to divide the at least three modes selected by the second mode selection module into at least two mode groups, where one mode group includes two modes;

[0248] The data acquisition module: configured to respectively define the two modes in the mode group as a first mode and a second mode; and respectively obtain a first downstream propagation time and a first upstream propagation time in the first mode, and a second downstream propagation time and a second upstream propagation time in the second mode through the received signals;

[0249] The second calculation module: configured to calculate the volumetric flow rate under the mode group using the following model; and calculate the flow rate mean according to the volumetric flow rate;

[0250] Wherein, ;

[0251]

[0252] ;

[0253] wherein, is the volumetric flow rate, is the first downstream propagation time, is the first upstream propagation time, is the second downstream propagation time, is the second upstream propagation time, is the first coefficient, is the second coefficient, is the third coefficient, is the fluid flow velocity, is the distance between the first probe and the second probe, is the pipe radius in the system to be measured.

[0254] In some specific embodiments, the multi-modal ultrasonic flow fusion system based on includes:

[0255] Model construction module: configured to pre-construct a modal number selection model, and the steps of pre-constructing the modal number selection model include setting at least two modal number ranges and respectively matching corresponding modal selection numbers for the at least two modal number ranges;

[0256] Second acquisition module: configured to respectively transmit a first transmission signal and a second transmission signal by using a first probe and a second probe, and correspondingly acquire a first received signal and a second received signal; wherein, at least three modes are generated during the propagation process of the first transmission signal or the second transmission signal in the system to be measured;

[0257] Modal number matching module: configured to match a corresponding modal selection number in the modal number selection model according to the number of modes acquired in the second acquisition module, and the modal selection number is greater than or equal to three;

[0258] Modal group division module: configured to select at least three modes from the modes according to the modal selection number and divide the selected modes into at least two modal groups, wherein one of the modal groups includes two modes;

[0259] Data acquisition module: configured to respectively define the two modes in the modal group as a first mode and a second mode; and respectively acquire the first downstream propagation time and the first upstream propagation time in the first mode, and the second downstream propagation time and the second upstream propagation time in the second mode through the received signals;

[0260] The second calculation module: configured to calculate the volume flow rate under the mode group by using the following formula; and calculate the average flow rate according to the volume flow rate;

[0261] Wherein, ;

[0262]

[0263] ;

[0264] In the formula, is the volume flow rate, is the first downstream propagation time, is the first upstream propagation time, is the second downstream propagation time, is the second upstream propagation time, is the first coefficient, is the second coefficient, is the third coefficient, is the fluid flow velocity, is the distance between the first probe and the second probe, is the pipe radius in the system to be measured.

[0265] In some embodiments, it further includes:

[0266] The second correction module: configured to correct the volume flow rate, and the correction method is to multiply the volume flow rate by a pre-obtained calibration coefficient.

[0267] In some embodiments, when the second correction module obtains the calibration coefficient, it is specifically configured to: conduct a preliminary experiment under experimental conditions to respectively obtain the actual flow rate result of the current mode group in the calibration area under the experimental conditions and the calculated flow rate result ;

[0268] According to the actual flow rate result and the calculated flow rate result calculate the calibration coefficient ; wherein,

[0269] .

[0270] In some embodiments, when obtaining the calibration coefficient, the second correction module is further configured to repeat the preliminary experiment under different experimental conditions to obtain the calibration coefficients under different experimental conditions, where the experimental conditions at least include the number of modes; correspondingly, before correcting the volume flow rate, the second correction module is further configured to obtain the current condition and match the experimental conditions according to the current condition to obtain the calibration coefficient matched under the current condition.

[0271] In some embodiments, when the mode group division module selects at least three modes from the modes according to the selected number of modes, it is specifically configured to determine whether the current mode meets the selection condition, where the selection condition requires that the amplitude of the received signal in the current mode is greater than the first preset amplitude threshold, and / or the signal length of the received signal in the current mode conforms to the first preset length threshold range; if so, select the mode, otherwise do not select the mode.

[0272] In some embodiments, the mode group division module is further configured to determine whether the amplitude of the received signal in the current mode is less than the second preset amplitude threshold; if so, select the mode, otherwise do not select the mode.

[0273] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including that element.

[0274] The embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope protected by the claims of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. A multimodal-based ultrasonic flow fusion method, characterized in that Including the following steps: S200, respectively transmitting a first transmission signal and a second transmission signal by using a first probe and a second probe, and correspondingly collecting a first received signal and a second received signal; wherein, at least three modes are generated during the propagation of the first transmission signal or the second transmission signal in the system to be measured, and the first received signal or the second received signal includes received signals in the at least three modes; S201, selecting at least three modes from the modes generated in S200; S202, dividing the at least three modes selected in S201 into at least two mode groups, wherein one mode group includes two modes; S203, respectively defining the two modes in the mode group as a first mode and a second mode; respectively obtaining a first downstream propagation time and a first upstream propagation time in the first mode, and a second downstream propagation time and a second upstream propagation time in the second mode through the received signals, and calculating the volumetric flow rate in the mode group by using the following model; Among them, ; ； In the formula, is the volume flow rate, is the first downstream propagation time, is the first upstream propagation time, is the second downstream propagation time, is the second upstream propagation time, is the first coefficient, is the second coefficient, is the third coefficient, is the fluid flow velocity, is the distance between the first probe and the second probe, is the pipe radius in the system to be measured; S205, calculating a flow rate average value according to at least two of the volumetric flow rates.

2. The multimodal-based ultrasonic flow fusion method according to claim 1, wherein Before S205, it further includes the step of: S204, correcting the volumetric flow rate, and the correction method is to multiply the volumetric flow rate by a pre-obtained calibration coefficient.

3. The multimodal-based ultrasonic flow fusion method according to claim 2, characterized in that In S204, the method for obtaining the calibration coefficient includes: S41. Conduct a preliminary experiment under experimental conditions to respectively obtain the actual flow rate results of the current modal group within the calibration region under the experimental conditions and the calculated flow rate results ; wherein, the calibration region is the region corresponding to at least two modes among the multiple modes obtained through the preliminary experiment; S42, according to the actual flow result and the calculated flow result calculate the calibration coefficient ; 。 4. A multimodal-based ultrasonic flow fusion method according to claim 3, characterized in that, When obtaining the calibration coefficient, it further includes the step of: S43, repeating the pre-experiment under different experimental conditions to obtain calibration coefficients under different experimental conditions, and the experimental conditions at least include the number of modes; Correspondingly, in S204, before correcting the volumetric flow rate, it further includes: Obtaining the current condition, and matching the current condition with the experimental conditions to obtain the calibration coefficient matched under the current condition.

5. A multimodal-based ultrasonic flow fusion method according to claim 3, characterized in that, In S204, before correcting the volumetric flow rate, it further includes the step of: S206, obtaining the current condition and matching the current condition with the experimental conditions, and its specific steps include: S61, obtaining at least three groups of received signals of at least three modes in the calibration region under the current condition, and at least three groups of standard received signals measured in at least three modes in the calibration region under the experimental conditions; S62, respectively calculating the amplitude differences between the received signals and the standard received signals to obtain at least three amplitude differences; S63, judging whether the at least three amplitude differences are all less than a first preset difference, and if so, matching the current condition with the experimental conditions; S207, obtaining the calibration coefficient under the experimental conditions.

6. The multimodal-based ultrasonic flow fusion method according to claim 1, wherein In S201, the specific steps for selecting at least three modes include: judging whether the current mode meets the selection condition, and the selection condition requires that the amplitude of the received signal in the current mode is greater than a first preset amplitude threshold, and / or the signal length of the received signal in the current mode conforms to a first preset length threshold range; if so, selecting the mode, otherwise not selecting the mode.

7. A multi-modal based ultrasonic flow fusion system, characterized in that, Including: Second acquisition module: Configured to respectively transmit a first transmission signal and a second transmission signal using a first probe and a second probe, and correspondingly acquire a first received signal and a second received signal; wherein, at least three modes are generated during the propagation process of the first transmission signal or the second transmission signal in the system to be measured, and the first received signal or the second received signal includes the received signals in the at least three modes; Second mode selection module: Configured to select at least three modes from the modes acquired by the second acquisition module; Mode group division module: Configured to divide the at least three modes selected by the second mode selection module into at least two mode groups, wherein one mode group includes two modes; Data acquisition module: Configured to respectively define the two modes in the mode group as a first mode and a second mode; and respectively obtain a first downstream propagation time and a first upstream propagation time in the first mode, and a second downstream propagation time and a second upstream propagation time in the second mode through the received signals; Second calculation module: Configured to calculate the volumetric flow rate under the mode group using the following model; and calculate the flow rate average value based on at least two of the volumetric flow rates; Among them, ; ； Wherein, is the volume flow rate, is the first downstream propagation time, is the first upstream propagation time, is the second downstream propagation time, is the second upstream propagation time, is the first coefficient, is the second coefficient, is the third coefficient, is the fluid flow velocity, is the distance between the first probe and the second probe, is the pipe radius in the system to be measured.

8. A multimodal-based ultrasonic flow fusion system according to claim 7, characterized in that, Further includes: Second correction module: Configured to correct the volumetric flow rate, and the correction method is to multiply the volumetric flow rate by a pre-obtained calibration coefficient.

9. A multimodal-based ultrasonic flow fusion system according to claim 8, characterized in that, When the second correction module obtains the calibration coefficient, it is specifically configured to: A preliminary experiment is carried out under experimental conditions to respectively obtain the actual flow results of the current mode group in the calibration area under the experimental conditions and the calculated flow results ; wherein, the calibration area is an area corresponding to at least two modes among multiple modes obtained through the preliminary experiment Based on the actual flow result and the calculated flow result calculate the calibration coefficient ; wherein 。 10. A multimodal-based ultrasonic flow fusion system according to claim 9, wherein, When the second correction module obtains the calibration coefficient, it is further configured to repeat the pre-experiment under different experimental conditions to obtain calibration coefficients under different experimental conditions, and the experimental conditions at least include the number of modes; correspondingly, before the second correction module corrects the volumetric flow rate, it is further configured to obtain the current condition and match the experimental conditions according to the current condition to obtain the calibration coefficient matched under the current condition.

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