A Time Difference Ultrasonic Flow Measurement Method and Device Based on Improved Wavelet Transform

Abstract

The present application discloses a time difference ultrasonic flow measurement method and device based on improved wavelet transform. The time difference ultrasonic flow measurement method based on improved wavelet transform includes: obtaining basic information in the current pipeline; obtaining a preset wavelet threshold database, where the preset wavelet threshold database includes at least one preset wavelet threshold and a preset score; generating a basic score according to the basic information in the current pipeline; obtaining the preset wavelet threshold corresponding to the preset score identical to the basic score; obtaining the time difference signal in the current pipeline; performing wavelet threshold denoising on the time difference signal to obtain the denoised time difference signal; and obtaining the flow information in the current pipeline according to the obtained time difference signal. The present application provides a suitable wavelet threshold for wavelet threshold denoising according to the situation in the pipeline, so that during noise filtering, different thresholds can be used for filtering according to the specific situation of the pipeline, preventing waves that should not be filtered from being filtered out.

Description

Technical Field

[0001] The present application relates to the technical field of ultrasonic flow detection, and particularly relates to a time-difference ultrasonic flow measurement method based on improved wavelet transform and a time-difference ultrasonic flow measurement device based on improved wavelet transform. Background Art

[0002] In the prior art, when measuring the flow rate, the ultrasonic detection signal is usually mixed with noises of different degrees and various types, which brings difficulties to the defect identification and characteristic characterization of materials. The reasons for these noises are usually as follows:

[0003] (1) There are various physical interferences at the work site, which cause phenomena such as pipeline vibration.

[0004] (2) The influence of the temperature and pressure of the fluid on the ultrasonic propagation speed in the fluid.

[0005] (3) Other noises such as those generated by the circuit.

[0006] The traditional noise reduction method is to pass the signal interfered by noise through a filter to filter out the frequency components of the noise. However, this method has certain limitations in dealing with pulse signals, white noise, non-stationary signals, etc. Therefore, people thought of using time-domain analysis for time-frequency filtering and denoising. The short-time Fourier transform and the generalized Fourier transform distribution used to be the main contents of time-domain analysis, and they have unique advantages in time-frequency filtering and denoising, but their fast calculation is relatively difficult.

[0007] Therefore, it is desired to have a technical solution to overcome or at least mitigate at least one of the above-mentioned defects of the prior art. Summary of the Invention

[0008] The purpose of the present invention is to provide a time-difference ultrasonic flow measurement method based on improved wavelet transform to overcome or at least mitigate at least one of the above-mentioned defects of the prior art.

[0009] In one aspect of the present invention, there is provided a time-difference ultrasonic flow measurement method based on improved wavelet transform, and the time-difference ultrasonic flow measurement method based on improved wavelet transform includes:

[0010] Obtain the basic information in the current pipeline;

[0011] Obtain a preset wavelet threshold database, where the preset wavelet threshold database includes at least one preset wavelet threshold and a preset score, and one preset score corresponds to one preset wavelet threshold;

[0012] Generate a basic score according to the basic information in the current pipeline;

[0013] Obtain a preset wavelet threshold corresponding to a preset score equal to the basic score;

[0014] Obtain the time difference signal in the current pipeline;

[0015] Perform wavelet threshold denoising on the time difference signal according to the wavelet threshold to obtain the denoised time difference signal;

[0016] Obtain the flow information in the current pipeline according to the obtained time difference signal.

[0017] Optionally, the obtaining of the basic information in the current pipeline includes any one of the following:

[0018] Obtain the pipeline vibration information;

[0019] Obtain the fluid temperature information in the pipeline;

[0020] Obtain the pressure information of the fluid in the pipeline on the inner wall of the pipeline.

[0021] Optionally, when the basic information in the current pipeline is three, the generating of the basic score according to the basic information in the current pipeline includes:

[0022] Obtain the vibration score according to the pipeline vibration information;

[0023] Obtain the temperature score according to the fluid temperature information in the pipeline;

[0024] Obtain the pressure score according to the pressure information of the fluid in the pipeline on the inner wall of the pipeline;

[0025] Select the largest one among the vibration score, temperature score, and pressure score as the basic score.

[0026] Optionally, the obtaining of the vibration score according to the pipeline vibration information includes:

[0027] Obtain the pipeline vibration frequency;

[0028] Obtain a vibration frequency score comparison table, which includes a preset vibration frequency range and a vibration score, and one preset vibration frequency range corresponds to one vibration score;

[0029] Obtain the vibration score corresponding to the preset vibration frequency range where the pipeline vibration frequency is located.

[0030] Optionally, the obtaining of the temperature score according to the fluid temperature information in the pipeline includes:

[0031] Obtain the fluid temperature in the pipeline;

[0032] Obtain a temperature score comparison table, which includes a preset temperature range and a temperature score, and one preset temperature range corresponds to one temperature score;

[0033] Obtain the temperature score corresponding to the preset temperature range where the temperature of the fluid in the pipeline is located.

[0034] Optionally, the obtaining of the pressure score according to the pressure information of the fluid in the pipeline on the inner wall of the pipeline includes:

[0035] Obtain the pressure of the fluid in the pipeline on the inner wall of the pipeline;

[0036] Obtain a pressure score comparison table, where the pressure score comparison table includes a preset pressure range and a pressure score, and one preset pressure range corresponds to one pressure score;

[0037] Obtain the pressure score corresponding to the preset pressure range where the pressure of the fluid in the pipeline on the inner wall of the pipeline is located.

[0038] Optionally, when using the wavelet threshold to perform wavelet threshold denoising on the time difference signal, the following threshold function is adopted:

[0039] Wherein,

[0040] f(x) is the threshold function; a and b are constants greater than 1; λ is the preset wavelet threshold.

[0041] The present application also provides a time difference ultrasonic flow measurement device based on improved wavelet transform. The time difference ultrasonic flow measurement device based on improved wavelet transform includes:

[0042] A current pipeline internal basic information acquisition module, which is used to acquire the current pipeline internal basic information;

[0043] A preset wavelet threshold database acquisition module, which is used to acquire a preset wavelet threshold database. The preset wavelet threshold database includes at least one preset wavelet threshold and a preset score, and one preset score corresponds to one preset wavelet threshold;

[0044] A basic score acquisition module, which is used to generate a basic score according to the current pipeline internal basic information;

[0045] A preset wavelet threshold acquisition module, which is used to acquire the preset wavelet threshold corresponding to the preset score that is the same as the basic score;

[0046] A time difference signal acquisition module, which is used to acquire the time difference signal in the current pipeline;

[0047] A denoising module, which is used to perform wavelet threshold denoising on the time difference signal according to the wavelet threshold, so as to obtain the denoised time difference signal;

[0048] The current pipeline flow information acquisition module is configured to obtain the current pipeline flow information according to the acquired time difference signal.

[0049] Beneficial effects:

[0050] The time-difference ultrasonic flow measurement method based on improved wavelet transform of the present application provides a suitable wavelet threshold for wavelet threshold denoising according to the situation in the pipeline, so that when filtering noise, different thresholds can be used for filtering according to the specific situation of the pipeline, preventing waves that should not be filtered from being filtered out. Description of the Drawings

[0051] Figure 1 It is a schematic flowchart of the time-difference ultrasonic flow measurement method based on improved wavelet transform according to an embodiment of the present application.

[0052] Figure 2 It is an electronic device for implementing Figure 1 the time-difference ultrasonic flow measurement method based on improved wavelet transform shown in the figure.

[0053] Figure 3 It is a schematic diagram of the time difference signal in an embodiment of the present application.

[0054] Figure 4 It is another schematic diagram of the time difference signal in an embodiment of the present application.

[0055] Figure 5 It is a data comparison diagram of the wavelet denoising algorithm in an embodiment of the present application.

[0056] Figure 6 It is another data comparison diagram of the wavelet denoising algorithm in an embodiment of the present application. Detailed Embodiments

[0057] To make the purpose, technical solutions, and advantages of the implementation of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of the present application. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application and should not be construed as limiting the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0058] It should be noted that in the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance.

[0059] Figure 1 It is a schematic flowchart of a time-difference ultrasonic flow measurement method based on improved wavelet transform according to an embodiment of the present application.

[0060] As Figure 1 shown, the time-difference ultrasonic flow measurement method based on improved wavelet transform includes:

[0061] Step 1: Obtain the basic information in the current pipeline;

[0062] Step 2: Obtain a preset wavelet threshold database, where the preset wavelet threshold database includes at least one preset wavelet threshold and a preset score, and one preset score corresponds to one preset wavelet threshold;

[0063] Step 3: Generate a basic score according to the basic information in the current pipeline;

[0064] Step 4: Obtain the preset wavelet threshold corresponding to the preset score that is the same as the basic score;

[0065] Step 5: Obtain the time-difference signal in the current pipeline;

[0066] Step 6: Perform wavelet threshold denoising on the time-difference signal according to the wavelet threshold to obtain the denoised time-difference signal;

[0067] Step 7: Obtain the flow information in the current pipeline according to the obtained time-difference signal.

[0068] The time-difference ultrasonic flow measurement method based on improved wavelet transform of the present application provides a suitable wavelet threshold for wavelet threshold denoising according to the situation in the pipeline, so that when performing noise filtering, different thresholds can be used for filtering according to the specific situation of the pipeline, preventing waves that should not be filtered from being filtered.

[0069] See Figure 3 and Figure 4 , Figure 3 represents the noise situation in the first state of the basic information in the current pipeline, Figure 4 represents the noise situation in the second state of the basic information in the current pipeline. It can be seen from Figure 3 and Figure 4 that Figure 3 has a significantly larger noise amplitude. If the same wavelet threshold is used for both choices, there may be a possibility of filtering out the clutter of Figure 3 but not being able to filter out the clutter of Figure 4 .

[0070] In this embodiment, the obtaining of the basic information in the current pipeline includes any one of the following:

[0071] Obtaining pipeline vibration information;

[0072] Obtaining the fluid temperature information in the pipeline;

[0073] Obtaining the pressure information of the fluid in the pipeline on the inner wall of the pipeline.

[0074] In this embodiment, when there are 3 pieces of basic information in the current pipeline, the generating of the basic score according to the basic information in the current pipeline includes:

[0075] Obtaining a vibration score according to the pipeline vibration information;

[0076] Obtaining a temperature score according to the fluid temperature information in the pipeline;

[0077] Obtaining a pressure score according to the pressure information of the fluid in the pipeline on the inner wall of the pipeline;

[0078] Selecting the largest one among the vibration score, the temperature score, and the pressure score as the basic score.

[0079] In this embodiment, the obtaining of the vibration score according to the pipeline vibration information includes:

[0080] Obtaining the pipeline vibration frequency;

[0081] Obtaining a vibration frequency score comparison table, where the vibration frequency score comparison table includes a preset vibration frequency range and a vibration score, and one preset vibration frequency range corresponds to one vibration score;

[0082] Obtaining the vibration score corresponding to the preset vibration frequency range where the pipeline vibration frequency is located.

[0083] In this embodiment, the obtaining of the temperature score according to the fluid temperature information in the pipeline includes:

[0084] Obtaining the fluid temperature in the pipeline;

[0085] Obtaining a temperature score comparison table, where the temperature score comparison table includes a preset temperature range and a temperature score, and one preset temperature range corresponds to one temperature score;

[0086] Obtaining the temperature score corresponding to the preset temperature range where the fluid temperature in the pipeline is located.

[0087] In this embodiment, the obtaining of the pressure score according to the pressure information of the fluid in the pipeline on the inner wall of the pipeline includes:

[0088] Obtaining the pressure of the fluid in the pipeline on the inner wall of the pipeline;

[0089] Obtain a pressure score comparison table, where the pressure score comparison table includes a preset pressure range and a pressure score, and one preset pressure range corresponds to one pressure score;

[0090] Obtain the pressure score corresponding to the preset pressure range where the pressure of the fluid in the pipeline on the inner wall of the pipeline is located.

[0091] In this embodiment, the vibration frequency score comparison table can be obtained through experiments, that is, obtain the influence of vibration frequency on noise through experiments. For example, obtain the time difference signal under the condition of no vibration and other equal experimental conditions, and compare it with the time difference signals under different vibration conditions and other equal experimental conditions, and set a score for each vibration condition according to the comparison results.

[0092] In this embodiment, the temperature score comparison table can be obtained through experiments, that is, obtain the influence of temperature on noise through experiments.

[0093] In this embodiment, the pressure score comparison table can be obtained through experiments, that is, obtain the influence of pressure on noise through experiments.

[0094] In this embodiment, when using the wavelet threshold to perform wavelet threshold denoising on the time difference signal, the following threshold function is adopted:

[0095] Among them,

[0096] f(x) is the threshold function; a and b are constants greater than 1; λ is the preset wavelet threshold.

[0097] In this embodiment, the following method is adopted to obtain the current pipeline flow information according to the obtained time difference signal:

[0098] When calculating the instantaneous flow velocity and flow rate, the line average flow velocity is used. It can be known from fluid mechanics that the surface average flow velocity has different correction coefficients according to different states of the fluid;

[0099] Let the correction coefficient be K, and the cumulative flow rate Q of the fluid is calculated as:

[0100] Among them,

[0101] vl is the fluid linear velocity, which is obtained according to the following formula:

[0102] The value of vl is:

[0103]

[0104] The first ultrasonic transducer P1 and the second ultrasonic transducer P2 are arranged before and after in the water flow direction; it is stipulated that the distance between the transducer and the reflector is s, the speed of ultrasonic waves in water is c, the included angle between the reflector and the horizontal plane is 45°, the center distance between the two reflectors is L, the pipe diameter is D, and the forward flow velocity of water, i.e., the linear velocity, is v l , K represents the correction coefficient; Q is the cumulative flow rate.

[0105] This application also provides a time-difference ultrasonic flow measurement device based on improved wavelet transform. The time-difference ultrasonic flow measurement device based on improved wavelet transform includes a basic information acquisition module for the current pipeline, a preset wavelet threshold database acquisition module, a basic score acquisition module, a preset wavelet threshold acquisition module, a time-difference signal acquisition module, a denoising module, and a flow information acquisition module for the current pipeline,

[0106] The basic information acquisition module for the current pipeline is used to acquire the basic information of the current pipeline;

[0107] The preset wavelet threshold database acquisition module is used to acquire a preset wavelet threshold database, and the preset wavelet threshold database includes at least one preset wavelet threshold and a preset score, and one preset score corresponds to one preset wavelet threshold;

[0108] The basic score acquisition module is used to generate a basic score according to the basic information of the current pipeline;

[0109] The preset wavelet threshold acquisition module is used to acquire the preset wavelet threshold corresponding to the same preset score as the basic score;

[0110] The time-difference signal acquisition module is used to acquire the time-difference signal in the current pipeline;

[0111] The denoising module is used to perform wavelet threshold denoising on the time-difference signal according to the wavelet threshold, so as to obtain the denoised time-difference signal;

[0112] The flow information acquisition module for the current pipeline is used to acquire the flow information in the current pipeline according to the acquired time-difference signal.

[0113] In this embodiment, the wavelet threshold denoising algorithm is converted from the time domain to the frequency domain and has the characteristics of multi-scale analysis, and can effectively distinguish signals and noise at different decomposition levels. Using the 1-D wavelet threshold denoising algorithm can effectively improve the measurement accuracy and stability of the ultrasonic flowmeter.

[0114] Due to the complexity of the wavelet denoising algorithm, it is necessary to select suitable wavelet denoising parameters through experimental analysis using simulation software, and then convert them into C code for use. However, this C code algorithm is bloated and occupies too much memory, making it impossible to be transplanted to the MCU microcontroller for operation. Compared with the resources of a PC computer, the MCU microcontroller has a slow computing speed, scarce memory resources, and a small FLASH capacity. The wavelet denoising algorithm that runs easily on MATLAB cannot be directly transplanted to the MCU after being converted into C code, showing problems such as large computational volume, bloated C code, and excessive memory occupation.

[0115] The specific parameters of the lightweight wavelet threshold denoising algorithm used in this application are as follows:

[0116] (1) Parameters:

[0117] Attribute Parameter Range Wavelet mother function DbN 4 - 8 orders Fixed threshold method Sqtwolog Threshold s, h Soft and hard thresholds Wavelet decomposition level Level 1 - 9 layers

[0118] (2) Memory occupation situation:

[0119]

[0120] See Figure 5 and Figure 6 , the effect of using the lightweight wavelet threshold denoising algorithm of this application is as Figure 5 and Figure 6 shown. In Figure 5 and Figure 6 , Input data = the original water volume data is the curve indicated by 1, pcwden = the result of MATLAB simulation operation is the curve indicated by 2, and mcuwden = the actual operation result of the algorithm of the present invention on the MCU is the curve indicated by 3.

[0121] From Figure 5 , Figure 6 it can be seen that the results show that the lightweight wavelet denoising algorithm running on the MCU has an obvious denoising effect, solving the pain points and difficulties of the original MATLAB wavelet denoising algorithm, such as bloated C code, slow computing speed, high memory occupation, and difficulty in transplantation.

[0122] The above description of the method also applies to the description of the device.

[0123] This application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the computer program, it implements the above-mentioned time difference ultrasonic flow measurement method based on improved wavelet transform.

[0124] The present application also provides a computer-readable storage medium storing a computer program, which when executed by a processor can implement the time-difference ultrasonic flow measurement method based on improved wavelet transform as described above.

[0125] Figure 2 It is an exemplary structural diagram of an electronic device capable of implementing the time-difference ultrasonic flow measurement method based on improved wavelet transform provided by an embodiment of the present application.

[0126] As Figure 2 shown, the electronic device includes an input device 501, an input interface 502, a central processing unit 503, a memory 504, an output interface 505, and an output device 506. Among them, the input interface 502, the central processing unit 503, the memory 504, and the output interface 505 are interconnected through a bus 507. The input device 501 and the output device 506 are respectively connected to the bus 507 through the input interface 502 and the output interface 505, and then connected to other components of the electronic device. Specifically, the input device 501 receives input information from the outside and transmits the input information to the central processing unit 503 through the input interface 502; the central processing unit 503 processes the input information based on the computer-executable instructions stored in the memory 504 to generate output information, temporarily or permanently stores the output information in the memory 504, and then transmits the output information to the output device 506 through the output interface 505; the output device 506 outputs the output information to the outside of the electronic device for user use.

[0127] That is to say, Figure 2 the electronic device shown can also be implemented as including: a memory storing computer-executable instructions; and one or more processors that can implement the time-difference ultrasonic flow measurement method based on improved wavelet transform described in conjunction with Figure 1 when executing the computer-executable instructions.

[0128] In one embodiment, Figure 2 the electronic device shown can be implemented as including: a memory 504 configured to store executable program code; one or more processors 503 configured to run the executable program code stored in the memory 504 to execute the time-difference ultrasonic flow measurement method based on improved wavelet transform in the above embodiment.

[0129] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and a memory.

[0130] The memory may include non-permanent memory in the form of computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. The memory is an example of computer-readable media.

[0131] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can store information by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices, or any other non-transitory media that can be used to store information that can be accessed by a computing device.

[0132] Those skilled in the art will appreciate that the embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0133] In addition, it is obvious that the term "including" does not exclude other units or steps. The multiple units, modules, or devices recited in the apparatus claims may also be implemented by one unit or a general apparatus through software or hardware. The terms first, second, etc. are used to identify names and do not denote any particular order.

[0134] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code, which includes one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks marked may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as the combination of blocks in the block diagram and / or overall flowchart, may be implemented by a dedicated hardware-based system for performing the specified functions or operations, or may be implemented by a combination of dedicated hardware and computer instructions.

[0135] In this embodiment, the so-called processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0136] The memory can be used to store computer programs and / or modules. The processor realizes various functions of the device / terminal device by running or executing the computer programs and / or modules stored in the memory, and by calling the data stored in the memory. The memory may mainly include a program storage area and a data storage area. Among them, the program storage area may store an operating system, application programs required for at least one function (such as a sound playback function, an image playback function, etc.); the data storage area may store data created according to the use of the mobile phone (such as audio data, phone book, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one magnetic disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0137] In this embodiment, if the modules / units integrated in the device / terminal device are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, to implement all or part of the processes in the above-described embodiment methods of the present invention, it can also be completed by hardware related to computer program instructions. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-described various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0138] It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. Although this application is disclosed above with preferred embodiments, it is not actually used to limit this application. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of this application. Therefore, the protection scope of this application should be determined by the scope defined by the claims of this application.

[0139] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A time-difference ultrasonic flow measurement method based on improved wavelet transform, characterized in that The time difference ultrasonic flow measurement method based on improved wavelet transform includes: Obtain the basic information in the current pipeline; Obtain a preset wavelet threshold database, where the preset wavelet threshold database includes at least one preset wavelet threshold and a preset score, and one preset score corresponds to one preset wavelet threshold; Generate a basic score according to the basic information in the current pipeline; Obtain the preset wavelet threshold corresponding to the preset score that is the same as the basic score; Obtain the time difference signal in the current pipeline; Perform wavelet threshold denoising on the time difference signal according to the wavelet threshold, so as to obtain the denoised time difference signal; Obtain the flow information in the current pipeline according to the obtained time difference signal; The obtaining of the basic information in the current pipeline includes any one or more of the following: Obtain the pipeline vibration information; Obtain the fluid temperature information in the pipeline; Obtain the pressure information of the fluid in the pipeline on the inner wall of the pipeline; When the basic information in the current pipeline is three, the generating of the basic score according to the basic information in the current pipeline includes: Obtain the vibration score according to the pipeline vibration information; Obtain the temperature score according to the fluid temperature information in the pipeline; Obtain the pressure score according to the pressure information of the fluid in the pipeline on the inner wall of the pipeline; Select the largest one among the vibration score, temperature score, and pressure score as the basic score; When performing wavelet threshold denoising on the time difference signal using the wavelet threshold, the following threshold function is adopted: ; wherein, is a threshold function; a and b are constants greater than 1; is a preset wavelet threshold.

2. The time difference ultrasonic flow measurement method based on improved wavelet transform according to claim 1, characterized in that, The obtaining of the vibration score according to the pipeline vibration information includes: Obtain the pipeline vibration frequency; Obtain a vibration frequency score comparison table, where the vibration frequency score comparison table includes a preset vibration frequency range and a vibration score, and one preset vibration frequency range corresponds to one vibration score; Obtain the vibration score corresponding to the preset vibration frequency range where the pipeline vibration frequency is located.

3. The time difference ultrasonic flow measurement method based on improved wavelet transform according to claim 2, wherein, The obtaining of the temperature score according to the fluid temperature information in the pipeline includes: Obtain the fluid temperature in the pipeline; Obtain a temperature score comparison table, where the temperature score comparison table includes a preset temperature range and a temperature score, and one preset temperature range corresponds to one temperature score; Obtain the temperature score corresponding to the preset temperature range where the fluid temperature in the pipeline is located.

4. The time difference ultrasonic flow measurement method based on improved wavelet transform according to claim 3, characterized in that The obtaining of the pressure score according to the pressure information of the fluid in the pipeline on the inner wall of the pipeline includes: Obtain the pressure of the fluid in the pipeline on the inner wall of the pipeline; Obtain a pressure score comparison table, where the pressure score comparison table includes a preset pressure range and a pressure score, and one preset pressure range corresponds to one pressure score; Obtain the pressure score corresponding to the preset pressure range where the pressure of the fluid in the pipeline on the inner wall of the pipeline is located.

5. A time-difference ultrasonic flow measurement device based on improved wavelet transform, characterized in that, The time difference ultrasonic flow measurement device based on improved wavelet transform includes: A basic information acquisition module in the current pipeline, which is used to obtain the basic information in the current pipeline; A preset wavelet threshold database acquisition module, which is used to obtain a preset wavelet threshold database, where the preset wavelet threshold database includes at least one preset wavelet threshold and a preset score, and one preset score corresponds to one preset wavelet threshold; A basic score acquisition module, which is used to generate a basic score according to the basic information in the current pipeline; A preset wavelet threshold acquisition module, which is used to acquire a preset wavelet threshold corresponding to a preset score equal to the basic score; A time difference signal acquisition module, which is used to acquire the time difference signal in the current pipeline; A denoising module, which is used to perform wavelet threshold denoising on the time difference signal according to the wavelet threshold, so as to acquire the denoised time difference signal; A flow information acquisition module in the current pipeline, which is used to acquire the flow information in the current pipeline according to the acquired time difference signal; The acquisition of the basic information in the current pipeline includes any one or more of the following: Acquire pipeline vibration information; Acquire the fluid temperature information in the pipeline; Acquire the pressure information of the fluid in the pipeline on the inner wall of the pipeline; When the basic information in the current pipeline is three, the generation of the basic score according to the basic information in the current pipeline includes: Acquire a vibration score according to the pipeline vibration information; Acquire a temperature score according to the fluid temperature information in the pipeline; Acquire a pressure score according to the pressure information of the fluid in the pipeline on the inner wall of the pipeline; Select the largest one among the vibration score, the temperature score and the pressure score as the basic score; When using the wavelet threshold to perform wavelet threshold denoising on the time difference signal, the following threshold function is adopted: ; wherein, is a threshold function; a and b are constants greater than 1; is a preset wavelet threshold.

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