A modulation method for ultrasonic echo signals and an ultrasonic flow meter

Abstract

This application relates to the field of ultrasonic flow detection technology, and provides a modulation method for ultrasonic echo signals and an ultrasonic flow meter. The method includes: acquiring the current echo signal corresponding to the current ultrasonic excitation signal emitted by the ultrasonic flow meter to the target fluid; calculating the amplitude of multiple peaks in the echo waveform of the current echo signal to obtain the average amplitude of the current echo signal; if the average amplitude of the current echo signal satisfies a first preset condition, calculating the similarity in overall shape between the echo waveform envelope and the spindle-shaped envelope of the current echo signal to obtain a cross-correlation value; if the cross-correlation value is greater than a first preset threshold, calculating the flow rate data of the target fluid based on the specified echo signal determined by the current ultrasonic excitation signal. This method improves the stability of the echo signal during operation and enhances the measurement accuracy of the ultrasonic flow meter.

Description

Technical Field

[0001] This application belongs to the field of ultrasonic flow detection technology, and particularly relates to a modulation method for ultrasonic echo signals and an ultrasonic flow meter. Background Technology

[0002] Currently, ultrasonic flow meters utilize the propagation characteristics of ultrasonic waves in fluids, eliminating the need to cut pipes or contact the fluid. The flow rate can be measured simply by clamping the transducer directly onto the outer wall of the pipe.

[0003] Based on the measurement principle of ultrasonic flow meters, to achieve higher accuracy and repeatability, the waveform of the echo signal during measurement needs to conform to a spindle-shaped pattern. Furthermore, the signal strength of the echo signal must remain consistent throughout each run of the ultrasonic flow meter, and the overall shape of the echo signal should not undergo excessive deformation. However, extensive testing has revealed that as the ultrasonic flow meter operates over time, both the flow meter itself and the environment can influence the echo signal, such as weakening the signal strength and causing overall shape deformation, leading to decreased measurement accuracy. Summary of the Invention

[0004] This application provides a method for modulating ultrasonic echo signals and an ultrasonic flow meter, which can solve the technical problem that existing ultrasonic flow meters suffer from low measurement accuracy due to weakening echo signal intensity and shape deformation during long-term operation.

[0005] In a first aspect, embodiments of this application provide a method for modulating ultrasonic echo signals, comprising:

[0006] Obtain the current echo signal corresponding to the current ultrasonic excitation signal emitted by the ultrasonic flow meter to the target fluid;

[0007] The amplitudes of multiple peaks in the echo waveform of the current echo signal are calculated to obtain the average amplitude of the current echo signal.

[0008] If the average amplitude of the current echo signal satisfies the first preset condition, the similarity between the echo waveform envelope and the spindle-shaped envelope of the current echo signal in terms of overall shape is calculated to obtain the cross-correlation value; wherein, the first preset condition is used to characterize that the deviation between the average amplitude and the preset expected average amplitude is within a preset error range;

[0009] When the cross-correlation value is determined to be greater than a first preset threshold, the flow rate data of the target fluid is calculated based on the specified echo signal determined based on the current ultrasonic excitation signal.

[0010] Secondly, embodiments of this application provide a modulation device for ultrasonic echo signals, comprising:

[0011] The signal acquisition module is used to acquire the current echo signal corresponding to the current ultrasonic excitation signal emitted by the ultrasonic flow meter to the target fluid.

[0012] The amplitude calculation module is used to calculate the amplitude of multiple peaks in the echo waveform of the current echo signal to obtain the average amplitude of the current echo signal.

[0013] The first determining module is used to calculate the degree of similarity between the echo waveform envelope and the spindle-shaped envelope of the current echo signal in terms of overall shape, and obtain a cross-correlation value, when the average amplitude value of the current echo signal meets the first preset condition; wherein, the first preset condition is used to characterize that the deviation between the average amplitude value and the preset expected average amplitude value is within a preset error range;

[0014] The second determining module is used to calculate the flow rate data of the target fluid based on a specified echo signal determined based on the current ultrasonic excitation signal when the cross-correlation value is determined to be greater than a first preset threshold.

[0015] Thirdly, embodiments of this application provide an ultrasonic flow meter, including: a main control module, an ultrasonic transmitting module, an ultrasonic receiving module, a first transducer, and a second transducer, wherein...

[0016] The main control module is connected to the ultrasonic transmitting module and the ultrasonic receiving module respectively, and is used to generate ultrasonic pulse signals and analog voltage signals, and send the ultrasonic pulse signals and the analog voltage signals to the ultrasonic transmitting module.

[0017] The ultrasonic transmitting module is connected to the first transducer and is used to perform signal synthesis processing on the ultrasonic pulse signal and the analog voltage signal to generate an ultrasonic excitation signal, and send the ultrasonic excitation signal to the first transducer.

[0018] The first transducer is used to convert the ultrasonic excitation signal into an ultrasonic vibration signal and transmit the ultrasonic vibration signal to the target fluid, which then propagates through the target fluid as a propagation carrier, so that the second transducer receives the ultrasonic vibration signal and converts the ultrasonic vibration signal into an initial echo signal.

[0019] The ultrasonic receiving module is connected to the second transducer and is used to acquire the initial echo signal converted by the second transducer, amplify the initial echo signal through the ultrasonic receiving circuit, output the echo signal, and send the echo signal to the main control module.

[0020] The main control module is also used to execute the modulation method of the ultrasonic echo signal as described in any of the first aspects above.

[0021] Fourthly, embodiments of this application provide a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the modulation method of the ultrasonic echo signal described in any of the above claims.

[0022] Fifthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the modulation method for ultrasonic echo signals described in any of the preceding claims.

[0023] Sixthly, embodiments of this application provide a computer program product that, when run on a terminal device, causes the terminal device to execute the modulation method of the ultrasonic echo signal described in any one of the first aspects.

[0024] The beneficial effects of the embodiments in this application compared with the prior art are:

[0025] This application provides a method for modulating ultrasonic echo signals, comprising: acquiring a current echo signal corresponding to a current ultrasonic excitation signal emitted by an ultrasonic flowmeter to a target fluid; calculating the amplitude of multiple peaks in the echo waveform of the current echo signal to obtain an average amplitude of the current echo signal; then, if the average amplitude of the current echo signal satisfies a first preset condition, calculating the similarity in overall shape between the echo waveform envelope and the spindle-shaped envelope of the current echo signal to obtain a cross-correlation value. The first preset condition characterizes that the deviation between the average amplitude and a preset expected average amplitude is within a preset error range. Finally, if the cross-correlation value is determined to be greater than a first preset threshold, calculating the flow rate data of the target fluid based on a specified echo signal determined from the current ultrasonic excitation signal. This method, by periodically monitoring the amplitude and shape of the echo signal and changing the frequency and amplitude of the ultrasonic excitation signal according to the amplitude and shape of the echo signal, enables the echo signal to have better stability during operation, thereby improving the measurement accuracy of the ultrasonic flowmeter. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of an ultrasonic flow meter provided in one embodiment of this application;

[0028] Figure 2 This is a schematic flowchart of a method for synthesizing ultrasonic excitation signals according to an embodiment of this application;

[0029] Figure 3 This is a schematic diagram of an ultrasonic receiving circuit provided in one embodiment of this application;

[0030] Figure 4 This is a schematic flowchart of a modulation method for an ultrasonic echo signal provided in an embodiment of this application;

[0031] Figure 5 This is a schematic diagram illustrating the calculation process of the average amplitude of the current echo signal according to an embodiment of this application;

[0032] Figure 6 This is a schematic flowchart of a modulation method for an ultrasonic echo signal provided in another embodiment of this application;

[0033] Figure 7 This is a flowchart illustrating the process of generating the echo waveform envelope of an ultrasonic echo signal and determining the cross-correlation value, according to an embodiment of this application.

[0034] Figure 8 This is a flowchart illustrating the process of determining the optimal transmission frequency value corresponding to the optimal amplitude of the echo signal, according to an embodiment of this application.

[0035] Figure 9 This is a schematic diagram of experimental results regarding the influence of the transmitted amplitude of an ultrasonic excitation signal on the ultrasonic echo signal, provided in an embodiment of this application.

[0036] Figure 10 This is a schematic diagram of experimental results regarding the influence of the transmission frequency of an ultrasonic excitation signal on the ultrasonic echo signal, provided in an embodiment of this application.

[0037] Figure 11 This is a schematic diagram of experimental results regarding the influence of pipe diameter on ultrasonic echo signals, provided in an embodiment of this application.

[0038] Figure 12 This is a schematic diagram of the structure of an ultrasonic echo signal modulation device provided in an embodiment of this application;

[0039] Figure 13 This is a schematic diagram of the structure of a terminal device provided in an embodiment of this application. Detailed Implementation

[0040] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0041] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0042] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0043] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrases "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0044] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0045] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0046] An ultrasonic flow meter is an instrument used to measure the flow rate of fluids (liquid or gas). It utilizes the propagation characteristics of ultrasonic waves in fluids, allowing for fluid measurement without cutting pipes or contacting the fluid. The transducer is directly clamped to the outer wall of the pipe. The development of ultrasonic flow meters benefits from the maturity of piezoelectric ceramic materials, precision electronic timing technology, and digital signal processing technology. This makes it possible to accurately extract weak ultrasonic signals from complex noise backgrounds and calculate minute time differences, thus solving problems associated with traditional flow meters such as complex installation and maintenance, pressure loss, and wear of moving parts.

[0047] The core measurement principle of an ultrasonic flow meter is the ultrasonic time-of-flight method. Two sensors alternately act as transmitters and receivers. Ultrasonic waves travel faster in the direction of fluid flow and slower against the flow direction. The instrument precisely measures the difference between the downstream and upstream propagation times of the ultrasonic waves between the upstream and downstream sensors. This time difference is proportional to the average flow velocity of the fluid. Combined with known pipe diameter, channel length, channel angle, and the measured fluid velocity, the fluid velocity and flow rate can be calculated. The formula is as follows:

[0048] ;

[0049] ;

[0050] In the formula, The time it takes for the ultrasonic wave to travel downstream; This represents the time it takes for the ultrasound to travel against the current. The distance along which ultrasound travels in a liquid; The speed of sound for ultrasonic waves to propagate in a fluid; The velocity of the fluid;

[0051] According to the above formula, we can obtain:

[0052] ;

[0053] In the formula, For the time difference, .

[0054] As can be seen from the formula, to achieve higher accuracy and repeatability in a flow meter, it is necessary to ensure... , , Accuracy, time difference Common methods for obtaining the echo waveform include the phase method and the cross-correlation method. These two methods do not have strict requirements regarding the overall shape of the echo waveform, but... , Methods for obtaining echo signals include thresholding, envelope analysis, and zero-point detection. These methods require the echo signal waveform to conform to a spindle-shaped pattern, and the signal strength to remain consistent throughout each run, while also ensuring that the overall echo shape does not undergo excessive deformation. However, extensive testing has revealed that as the ultrasonic flowmeter operates for longer periods, both the flowmeter itself and the environment can influence the echo signal, such as weakening the signal strength or causing overall shape deformation.

[0055] This application proposes an echo signal modulation method for ultrasonic flow meters. By periodically monitoring the amplitude and shape of the echo signal, changing the frequency and amplitude of the excitation signal provided to the transducer, and altering the amplification factor of the receiving circuit, the echo signal exhibits better stability during operation, thus improving the accuracy and repeatability of the flow meter. Furthermore, this method can still monitor and modulate the echo signal in different liquids and pipe materials, ensuring the intensity and shape of the echo signal conform to set values. This allows the ultrasonic flow meter to be compatible with more liquids and sound-transmitting pipe materials, enabling more accurate measurement of flow velocity and flow rate in various liquids and pipe materials.

[0056] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of an ultrasonic flow meter according to an embodiment of this application. The ultrasonic flow meter 1 includes: a main control module 10, an ultrasonic transmitting module 20, an ultrasonic receiving module 30, a first transducer 40, and a second transducer 50.

[0057] The main control module 10 is connected to the ultrasonic transmitting module 20 and the ultrasonic receiving module 30 respectively. It is used to generate ultrasonic pulse signals and analog voltage signals and send the ultrasonic pulse signals and analog voltage signals to the ultrasonic transmitting module 20.

[0058] The ultrasonic transmitting module 20 is connected to the first transducer 40 and is used to perform signal synthesis processing on the ultrasonic pulse signal and the analog voltage signal to generate an ultrasonic excitation signal, and send the ultrasonic excitation signal to the first transducer 40.

[0059] The first transducer 40 is used to convert the ultrasonic excitation signal into an ultrasonic vibration signal and transmit the ultrasonic vibration signal to the target fluid. The ultrasonic vibration signal is transmitted through the target fluid as a propagation carrier so that the second transducer receives the ultrasonic vibration signal and converts the ultrasonic vibration signal into an initial echo signal.

[0060] The ultrasonic receiving module 30 is connected to the second transducer 50 and is used to collect the initial echo signal converted by the second transducer 50. The initial echo signal is amplified by the ultrasonic receiving circuit, the echo signal is output, and the echo signal is sent to the main control module 10.

[0061] The main control module 10 is also used to execute the modulation method of the ultrasonic echo signal.

[0062] like Figure 1 As shown, the ultrasonic flow meter 1 includes a main control module 10, an ultrasonic transmitting module 20, an ultrasonic receiving module 30, a first transducer 40, and a second transducer 50.

[0063] The main control module 10 is the core control component of the ultrasonic flow meter 1. It is mainly used to generate ultrasonic pulse signals and analog voltage signals and send these signals to the ultrasonic transmitting module 20. At the same time, the main control module 10 can also receive the echo signals returned by the ultrasonic receiving module, modulate the echo signals to obtain the specified echo signals, and perform overall control and data processing of the entire flow meter measurement operation.

[0064] The ultrasonic transmitting module 20 is connected to the main control module 10 and the first transducer 40. It is mainly used to perform signal synthesis processing on the ultrasonic pulse signal and analog voltage signal received from the main control module 10 to generate an ultrasonic excitation signal that can drive the first transducer 40 to work, and then send the ultrasonic excitation signal to the first transducer 40.

[0065] like Figure 2 As shown, Figure 2 This is a schematic flowchart illustrating a method for synthesizing ultrasonic excitation signals according to an embodiment of this application. Figure 2The specific process of signal synthesis processing of the ultrasonic pulse signal and the analog voltage signal by the ultrasonic transmitting module 20 is as follows: The voltage amplitude of the analog voltage signal generated by the main control module 10 is increased by the boost circuit 21 in the ultrasonic transmitting module 20 to obtain the boosted analog signal corresponding to the analog signal; simultaneously, the amplitude of the ultrasonic pulse signal is increased by the pulse signal amplification circuit 22 in the ultrasonic transmitting module 20 to obtain the amplified ultrasonic pulse signal corresponding to the ultrasonic pulse signal. Finally, the boosted analog signal and the amplified ultrasonic pulse signal are synthesized by the pulse signal amplification circuit 22 to obtain the ultrasonic excitation signal.

[0066] The main control module 10 primarily generates two key signals: an analog voltage signal and an ultrasonic pulse signal. The analog voltage signal, generated based on a pre-set excitation signal amplitude, controls the amplitude of the ultrasonic excitation signal. The ultrasonic pulse signal, on the other hand, adjusts the pulse characteristics of the ultrasonic excitation signal, such as pulse width and frequency. After being output from the main control module 10, the analog voltage signal enters the boost circuit 21. The main function of the boost circuit 21 is to increase the voltage amplitude of the analog voltage signal to a suitable value. Because the analog signal voltage after conversion by the digital-to-analog converter is usually too low to directly drive subsequent transducers and other loads, the voltage amplitude of the analog voltage signal needs to be increased to obtain a boosted analog signal that can drive the first transducer 40. After being output from the main control module 10, the ultrasonic pulse signal enters the pulse signal amplification circuit 22, which increases the amplitude of the ultrasonic pulse signal to generate a corresponding amplified ultrasonic pulse signal. The analog voltage signal (boosted analog signal) and the ultrasonic pulse signal (amplified ultrasonic pulse signal) are synthesized into an ultrasonic excitation signal in the pulse signal amplification circuit 22. The pulse signal amplification circuit 22 enhances the amplitude of the ultrasonic pulse signal while maintaining the integrity of its pulse shape. Finally, the ultrasonic excitation signal is input to the first transducer 40, which converts the electrical signal into a mechanical vibration signal (i.e., an ultrasonic vibration signal), thereby generating ultrasound.

[0067] The first transducer 40 is one of the key components in the ultrasonic flowmeter 1 that enables the conversion between electrical signals and ultrasonic vibration signals. The first transducer 40 is connected to the ultrasonic transmitting module 20, receives the ultrasonic excitation signal sent by the ultrasonic transmitting module 20, converts the ultrasonic excitation signal into an ultrasonic vibration signal, and transmits the ultrasonic vibration signal towards the target fluid. This allows the ultrasonic vibration signal to propagate through the target fluid, thereby enabling the second transducer 50 to receive the ultrasonic vibration signal. The ultrasonic vibration signal is a mechanical vibration signal generated by the first transducer 40 under the action of the ultrasonic excitation signal. This vibration propagates in the fluid in the form of ultrasound. When it encounters various conditions in the fluid (such as fluid flow, interfaces, etc.), reflection occurs, forming a signal that can be used to measure flow information. The second transducer 50 is another transducer component in the ultrasonic flowmeter 1. The second transducer 50 is connected to the ultrasonic receiving module 30, which can receive the ultrasonic vibration signal emitted by the first transducer 40 and convert the ultrasonic vibration signal into an initial echo signal. The initial echo signal is an electrical signal obtained by converting the ultrasonic vibration signal.

[0068] It should be noted that in the ultrasonic flow meter 1 of this embodiment, the specific arrangement of the first transducer 40 and the second transducer 50 depends on the type of flow meter. Common types of ultrasonic flow meters include clamp-on and insertion types. For example, in a clamp-on ultrasonic flow meter, the two transducers are usually installed on the outer wall of the fluid pipe, and they are generally arranged opposite or staggered on the same or different sides of the pipe at a certain angle (in the direction of flow or counterflow). In an insertion ultrasonic flow meter, the transducers are directly inserted into the interior of the fluid pipe through a special probe. They can be installed on the same cross-section of the fluid pipe and arranged opposite each other at a certain angle; or they can be inserted at different positions.

[0069] The ultrasonic receiving module 30 is connected to the second transducer 50 and the main control module 10. It can acquire the initial echo signal converted by the second transducer 50, amplify this initial echo signal through the ultrasonic receiving circuit, output a corresponding echo signal, and finally send this echo signal to the main control module 10. The main control module 10 then modulates the echo signal to obtain a specified echo signal. Because the ultrasonic vibration signal may weaken during propagation and conversion, the initial echo signal may be weak and requires further amplification. The ultrasonic receiving circuit receives the initial echo signal converted by the second transducer and amplifies it. The echo signal is the signal output after amplifying the initial echo signal. This amplified echo signal is more suitable for analysis and processing by the main control module 10 to extract information about fluid flow rate.

[0070] like Figure 3 As shown, Figure 3 This is a schematic diagram of an ultrasonic receiving circuit according to an embodiment of this application. This ultrasonic receiving circuit can amplify the initial echo signal. For example... Figure 3 In this embodiment, the ultrasonic receiving circuit is a dual-channel adjustable gain inverting amplifier circuit, which consists of two operational amplifiers, multiple resistors, and two switches. The negative input terminal of the first operational amplifier 31 is connected to the input signal (i.e., the initial echo signal) through the first resistor R1. The output terminal of the first operational amplifier 31 is connected to the input terminal of the second resistor R2 and the output terminal of the third resistor R3, while the output terminal of the first resistor R1 is also connected to the input terminal of the third resistor R3. The third resistor R3 and the fourth resistor R4 are connected in parallel by the first transistor 33 controlled by the first switch 32. When the first switch 32 is closed, the third resistor R3 and the fourth resistor R4 are connected in parallel, and the positive power supply VCC and the negative power supply GND (also called the ground terminal) supply power to the first operational amplifier 31. Simultaneously, the power supply VCC / 2 is connected to the positive input terminal of the first operational amplifier 31, providing a bias voltage to the first operational amplifier 31. Correspondingly, the negative input terminal of the second operational amplifier 34 is connected to the output terminal of the second resistor R2, and the output terminal of the second operational amplifier 34 is connected to the output terminals of the fifth resistor R5 and the sixth resistor R6. The fifth resistor R5 and the sixth resistor R6 are connected in parallel by the second transistor 36 controlled by the second switch 35. When the second switch 35 is closed, the fifth resistor R5 and the sixth resistor R6 are connected in parallel, and the positive power supply VCC and the negative power supply GND supply power the second operational amplifier 34. In addition, the power supply VCC / 2 is also connected to the positive input terminal of the second operational amplifier 34, which also provides a bias voltage for the second operational amplifier 34. The initial echo signal is amplified by the first operational amplifier 31 and the second operational amplifier 34, and then the echo signal is output through the output terminal of the second operational amplifier 34.

[0071] When the first switch 32 and the second switch 35 are open, the connection of the third resistor R3 and the fourth resistor R4, as well as the fifth resistor R5 and the sixth resistor R6, changes from parallel to open. This change adjusts the value of the feedback resistor, thereby altering the gain of the first operational amplifier 31 and the second operational amplifier 34. For example, in the first operational amplifier 31, when the first switch 32 is open, the fourth resistor R4 is disconnected, and the feedback resistor is determined solely by the third resistor R3, resulting in a change in the amplification factor. Similarly, in the second operational amplifier 34, when the second switch 35 is open, the sixth resistor R6 is disconnected, and the feedback resistor is determined solely by the fifth resistor R5. This design allows the ultrasonic receiving circuit to flexibly switch the amplification factor. When a higher amplification factor is needed, the first switch 32 or the second switch 35 can be placed in a position that reduces the feedback resistance (i.e., disconnecting the parallel resistors fourth resistor R4 or sixth resistor R6); conversely, when a lower amplification factor is needed, the parallel resistors (i.e., fourth resistor R4 or sixth resistor R6) can be closed to increase the value of the feedback resistor. By controlling the conduction and cutoff of the first transistor 33 and the second transistor 36 through the first switch 32 and the second switch 35, and by designing a reasonable feedback resistor value, an amplifier circuit with four programmable amplification factors can be provided: both the first switch 32 and the second switch 35 are closed; both the first switch 32 and the second switch 35 are open; the first switch 32 is closed and the second switch 35 is open; and the first switch 32 is open and the second switch 35 is closed.

[0072] Specifically, in this embodiment, during the flow rate measurement of the target fluid by the ultrasonic flowmeter 1, the main control module 10 generates basic ultrasonic pulse signals and analog voltage signals, and then sends these signals to the ultrasonic transmitting module 20. The ultrasonic transmitting module 20 amplifies the ultrasonic pulse signals and analog voltage signals sent by the main control module 10 by a certain factor, outputs an ultrasonic excitation signal, and sends this signal to the first transducer 40. The first transducer 40 converts the ultrasonic excitation signal into an ultrasonic vibration signal, which propagates through the target fluid medium to the second transducer 50, allowing the second transducer 50 to receive the ultrasonic vibration signal propagating in the target fluid. The second transducer 50 converts the received ultrasonic vibration signal into an initial echo signal. The ultrasonic receiving module 30 acquires the initial echo signal converted by the second transducer 50, amplifies it by a certain factor in the ultrasonic receiving circuit, outputs the echo signal corresponding to the ultrasonic excitation signal, and transmits this echo signal to the main control module 10. After acquiring the complete echo signal, the main control module 10 processes the echo signal using a specific algorithm to extract relevant parameters. Then, it modulates the echo signal until the extracted parameters match the algorithm's set values, thus completing the modulation of the ultrasonic echo signal. After obtaining the modulated ultrasonic echo signal, the flow rate data of the target fluid is calculated based on it.

[0073] It should be noted that the ultrasonic flow meter provided in this application embodiment can be applied to the flow control of high-purity cooling water, corrosive chemical reagents (such as media containing hydrofluoric acid), etc.; it can also measure the flow of various waters (such as cooling water, drinking water, neutral water, etc.); it can also monitor the flow in extreme environments (such as high temperature, low temperature, radiation); it can also be applied to precise measurement scenarios of small flow in medical and laboratory settings; and it can also be used for the measurement of flow of industrial wastewater and other liquids with a certain degree of corrosiveness.

[0074] Please see Figure 4 , Figure 4 This is a schematic flowchart illustrating a modulation method for an ultrasonic echo signal according to an embodiment of this application. The method includes:

[0075] S11. Obtain the current echo signal corresponding to the current ultrasonic excitation signal emitted by the ultrasonic flow meter to the target fluid.

[0076] S12. Calculate the amplitude of multiple peaks in the echo waveform of the current echo signal to obtain the average amplitude of the current echo signal.

[0077] S13. If the average amplitude of the current echo signal satisfies the first preset condition, the similarity in overall shape between the echo waveform envelope and the spindle-shaped envelope of the current echo signal is calculated to obtain the cross-correlation value. The first preset condition characterizes that the deviation between the average amplitude and the preset expected average amplitude is within a preset error range.

[0078] S14. When the cross-correlation value is determined to be greater than the first preset threshold, the flow rate data of the target fluid is calculated based on the specified echo signal determined based on the current ultrasonic excitation signal.

[0079] It should be noted that this method can be applied to the measurement of fluid flow rate using ultrasonic flow meters.

[0080] The target fluid is the fluid medium whose flow rate needs to be measured. This target fluid can be a liquid (such as water, oil, etc.) or a gas (such as air, natural gas, etc.). In this embodiment, the specific type of the target fluid is not limited. The current ultrasonic excitation signal is an electrical signal emitted by the ultrasonic flow meter to the target fluid to excite ultrasonic vibrations. This signal is converted into an ultrasonic vibration signal by the first transducer and propagates within the target fluid. The current echo signal is an electrical signal obtained after the ultrasonic vibration signal in the target fluid is reflected back from an obstacle (such as a fluid interface, pipe wall, etc.), received and processed by the second transducer.

[0081] In step S11, the current echo signal corresponding to the current ultrasonic excitation signal emitted by the ultrasonic flowmeter to the target fluid is acquired, including:

[0082] The main control module in the ultrasonic flow meter generates the current ultrasonic pulse signal and the current analog voltage signal.

[0083] The ultrasonic transmitter module in the ultrasonic flowmeter performs signal synthesis processing on the current ultrasonic pulse signal and the current analog voltage signal to generate the current ultrasonic excitation signal.

[0084] The ultrasonic excitation signal is sent to the first transducer in the ultrasonic flow meter via the ultrasonic transmitting module.

[0085] The first transducer converts the current ultrasonic excitation signal into a current ultrasonic vibration signal, so that the second transducer in the ultrasonic flowmeter receives the current ultrasonic vibration signal and converts the current ultrasonic vibration signal into an initial echo signal.

[0086] The ultrasonic receiving module in the ultrasonic flow meter acquires the initial echo signal converted by the second transducer, and the ultrasonic receiving circuit in the ultrasonic receiving module amplifies the initial echo signal to obtain the current echo signal corresponding to the current ultrasonic excitation signal.

[0087] Specifically, during the flow rate measurement of the target fluid by the ultrasonic flow meter, the main control module generates a current ultrasonic pulse signal and a current analog voltage signal. These signals are then sent to the ultrasonic transmitting module within the ultrasonic flow meter. The ultrasonic transmitting module amplifies the current ultrasonic pulse signal and the current analog voltage signal by a certain factor, outputting a current ultrasonic excitation signal, which is then sent to the first transducer in the ultrasonic flow meter. The first transducer converts the current ultrasonic excitation signal into a current ultrasonic vibration signal. This vibration signal propagates through the target fluid medium to the second transducer, which receives the transmitted ultrasonic vibration signal. The second transducer converts the received ultrasonic vibration signal into an initial echo signal. The ultrasonic receiving module acquires the initial echo signal converted by the second transducer, amplifies it by a certain factor in the ultrasonic receiving circuit, and outputs the current echo signal corresponding to the current ultrasonic excitation signal. This yields the current echo signal corresponding to the current ultrasonic excitation signal emitted by the ultrasonic flow meter to the target fluid.

[0088] In some examples, the ultrasonic transmitter module in the ultrasonic flowmeter performs signal synthesis processing on the current ultrasonic pulse signal and the current analog voltage signal to generate the current ultrasonic excitation signal, including:

[0089] The voltage amplitude of the current analog voltage signal is increased by the boost circuit in the ultrasonic transmitting module to obtain the boosted analog signal corresponding to the current analog voltage signal.

[0090] The amplitude of the current ultrasonic pulse signal is increased by the pulse signal amplification circuit in the ultrasonic transmitting module to obtain the amplified ultrasonic pulse signal corresponding to the current ultrasonic pulse signal.

[0091] The current ultrasonic excitation signal is obtained by combining the boosted analog signal and the amplified ultrasonic pulse signal through a pulse signal amplification circuit.

[0092] In this embodiment, the specific process of generating the current ultrasonic excitation signal by synthesizing the current ultrasonic pulse signal and the current analog voltage signal based on the ultrasonic transmitting module is as follows: The voltage amplitude of the current analog voltage signal generated by the main control module is increased by the boost circuit in the ultrasonic transmitting module to obtain the boosted analog signal corresponding to the current analog voltage signal; simultaneously, the amplitude of the current ultrasonic pulse signal is increased by the pulse signal amplification circuit in the ultrasonic transmitting module to obtain the amplified ultrasonic pulse signal corresponding to the current ultrasonic pulse signal. Finally, the boosted analog signal and the amplified ultrasonic pulse signal are synthesized by the pulse signal amplification circuit to obtain the current ultrasonic excitation signal.

[0093] It should be understood that since the analog signal voltage after conversion by the digital-to-analog converter is usually too low to directly drive subsequent loads such as transducers, it is necessary to increase the voltage amplitude of the current analog voltage signal to drive the first transducer. This method not only enhances the amplitude of the current ultrasonic pulse signal but also maintains the integrity of its pulse shape.

[0094] It should be noted that the echo waveform is the time-domain representation of the current echo signal, reflecting the amplitude change of the echo signal over time. The echo waveform contains multiple peaks and troughs. The amplitude of a peak represents the maximum deviation of the waveform; for the current echo signal, the amplitude of the peak indicates the intensity of the current echo signal (i.e., the reflected ultrasonic signal). The average amplitude is the sum of the amplitudes of the multiple peaks in the echo waveform, providing a comprehensive reflection of the overall intensity level of the current echo signal.

[0095] In step S12, the amplitudes of multiple peaks in the echo waveform of the current echo signal are calculated to obtain the average amplitude of the current echo signal, including:

[0096] Obtain the amplitude of each of the multiple peaks.

[0097] Determine whether the amplitude of each peak is greater than the preset minimum peak amplitude.

[0098] The peak with an amplitude greater than the preset minimum peak amplitude among the multiple peaks is taken as the target peak.

[0099] The amplitudes corresponding to the multiple target peaks are summed to obtain the total amplitude of the multiple peaks.

[0100] The average value of the total amplitude of the multiple wave peaks is calculated to obtain the average amplitude of the current echo signal.

[0101] like Figure 5 As shown, Figure 5 This is a schematic diagram illustrating the calculation process of the average amplitude of the current echo signal according to an embodiment of this application. Figure 5 In the current echo signal waveform, which contains multiple peaks, the amplitude of the first peak among these peaks is first obtained. It is then determined whether this amplitude is greater than a preset minimum peak amplitude. The preset minimum peak amplitude is a pre-defined minimum amplitude that can be used to calculate peak amplitudes. Peaks whose amplitudes are greater than the preset minimum peak amplitude are then selected as target peaks.

[0102] If the amplitude of the first peak is greater than the preset minimum peak amplitude, then the first peak can be used as a target peak, and its amplitude is recorded and added to the total amplitude of the current echo signal. If the amplitude of the first peak is less than or equal to the preset minimum peak amplitude, then the amplitude of the second peak among multiple peaks in the echo waveform of the current echo signal is obtained, and the amplitude of the second peak is further checked against the preset minimum peak amplitude. If the amplitude of the second peak is greater than the preset minimum peak amplitude, then... The second peak can be used as a target peak, and its amplitude can be recorded and added to the total amplitude of the current echo signal. If the amplitude of the second peak is less than or equal to the preset minimum peak amplitude, the amplitude of the next peak in the current echo signal can be obtained. If the amplitude of the next peak is greater than the preset minimum peak amplitude, the amplitude of the next peak can be added to the total amplitude of the current echo signal. In this way, other peaks among the multiple peaks in the echo waveform of the current echo signal can be judged.

[0103] Finally, determine whether there are any peaks in the echo waveform of the current echo signal that have not been evaluated in terms of amplitude. If there are no peaks that have not been evaluated in terms of amplitude, that is, the amplitude of all peaks has been evaluated, then calculate the average value of the total amplitude to obtain the average amplitude of the current echo signal.

[0104] If there are still peaks whose amplitude has not been determined, then the amplitude of the peaks whose amplitude has not been determined is acquired. The amplitude of the peaks whose amplitude has not been determined is compared with the preset minimum peak amplitude. If the amplitude of the peak whose amplitude has not been determined is greater than the preset minimum peak amplitude, then the peak whose amplitude has not been determined is taken as the target peak, and the amplitude of the peak whose amplitude has not been determined is added to the total amplitude of the current echo signal. This process continues until all peaks whose amplitude has not been determined have been determined, and the final total amplitude is obtained. The average value of the total amplitude is calculated to obtain the average amplitude of the current echo signal.

[0105] In other words, the process begins by processing the echo waveform of the current echo signal, acquiring the amplitude of the first peak, and then determining whether this peak amplitude is greater than a preset minimum peak amplitude. If the peak amplitude is less than or equal to the preset minimum peak amplitude, the process continues to acquire the amplitude of the next peak; if it is greater than the preset minimum peak amplitude, the amplitude of that peak is added to the total amplitude. Next, it is determined whether there are any more peaks in the current echo signal. If so, the amplitude of the next peak is acquired, and the above determination and accumulation process is repeated. When there are no more peaks in the current echo signal, the average value of the total amplitude is calculated, and the entire process ends. The purpose of this process is to progressively process each peak in the echo signal, filter out target peaks that meet the conditions, and calculate the total amplitude and average amplitude of the target peaks, thereby extracting the echo signal amplitude parameters.

[0106] It should be noted that the first preset condition is a condition for determining whether the average amplitude of the current echo signal meets the requirements, that is, the deviation between the average amplitude and the preset expected average amplitude is within a preset error range. In this embodiment, the first preset condition can be that the average amplitude of the current echo signal meets the requirements. .

[0107] The echo waveform envelope is a curve formed by connecting the vertices of the peaks in the echo waveform of the current echo signal, and it can describe the amplitude variation trend of the current echo signal. A spindle-shaped envelope is an envelope with a specific shape. The spindle-shaped envelope resembles a spindle in shape, being wider in the middle and narrower at both ends. In this embodiment, the spindle-shaped envelope can be used as a reference standard for comparison with the echo waveform envelope.

[0108] The cross-correlation value is an indicator that measures the degree of similarity between the echo waveform envelope and the spindle-shaped envelope in terms of overall shape. The value usually ranges from 0 to 1, and the closer the cross-correlation value is to 1, the higher the degree of similarity.

[0109] In step S13, after obtaining the average amplitude of the current echo signal, it is determined whether the average amplitude of the current echo signal meets the first preset condition, that is, whether the average amplitude of the current echo signal meets the condition. If the average amplitude of the current echo signal meets the first preset condition, the similarity between the echo waveform envelope and the spindle-shaped envelope of the current echo signal in terms of overall shape is calculated to obtain the cross-correlation value.

[0110] In step S14, after obtaining the cross-correlation value, the cross-correlation value is compared with a first preset threshold. The first preset threshold is a pre-set threshold used to determine whether the cross-correlation value meets the requirements. When the cross-correlation value is greater than this threshold, the echo waveform shape of the echo signal is considered to meet the expected requirements. In this embodiment, the first preset threshold can be set to 0.9, and the specific value of the first preset threshold is not limited.

[0111] If the cross-correlation value is determined to be greater than a first preset threshold, then the echo waveform shape of the current echo signal is determined to meet the expected requirements. The current echo signal corresponding to the current ultrasonic excitation signal is then designated as the specified echo signal, and the flow rate data of the target fluid is calculated based on this specified echo signal. The flow rate data can reflect information about the magnitude of the fluid flow rate, or information about the fluid flow velocity, etc.

[0112] It is understood that this application provides a method for modulating ultrasonic echo signals, including: acquiring the current echo signal corresponding to the current ultrasonic excitation signal emitted by an ultrasonic flowmeter to a target fluid; calculating the amplitude of multiple peaks in the echo waveform of the current echo signal to obtain the average amplitude of the current echo signal; then, if the average amplitude of the current echo signal satisfies a first preset condition, calculating the similarity in overall shape between the echo waveform envelope and the spindle-shaped envelope of the current echo signal to obtain a cross-correlation value. The first preset condition characterizes that the deviation between the average amplitude and the preset expected average amplitude is within a preset error range. Finally, if the cross-correlation value is determined to be greater than a first preset threshold, calculating the flow rate data of the target fluid based on the specified echo signal determined by the current ultrasonic excitation signal. This method, by periodically monitoring the amplitude and shape of the echo signal and changing the frequency and amplitude of the ultrasonic excitation signal according to the amplitude and shape of the echo signal, makes the echo signal more stable during operation and improves the measurement accuracy of the ultrasonic flowmeter.

[0113] In one possible implementation, after calculating the amplitude of multiple peaks in the echo waveform of the current echo signal to obtain the average amplitude of the current echo signal, the method includes:

[0114] If the average amplitude of the current echo signal does not meet the first preset condition, the amplification factor of the ultrasonic receiving circuit in the ultrasonic flowmeter or the transmission amplitude of the current ultrasonic excitation signal is adjusted according to the transmission amplitude of the current ultrasonic excitation signal and the preset maximum amplitude to obtain the next ultrasonic excitation signal.

[0115] like Figure 6 As shown, Figure 6This is a schematic flowchart illustrating a modulation method for ultrasonic echo signals according to another embodiment of this application. Figure 6 In this process, after obtaining the average amplitude of the current echo signal, it is determined whether the average amplitude of the current echo signal meets the first preset condition. If the average amplitude of the current echo signal does not meet the first preset condition, the amplification factor of the ultrasonic receiving circuit in the ultrasonic flowmeter or the transmission amplitude of the current ultrasonic excitation signal is adjusted according to the transmission amplitude of the current ultrasonic excitation signal and the preset maximum amplitude to obtain the next ultrasonic excitation signal. This next ultrasonic excitation signal is then transmitted into the target fluid through the first transducer to obtain the echo signal corresponding to the next ultrasonic excitation signal, thus obtaining an echo signal that meets the expected requirements. The transmission amplitude is the voltage or current amplitude of the current ultrasonic excitation signal, which determines the initial intensity of the transmitted ultrasonic wave. The preset maximum amplitude is the upper limit of the ultrasonic excitation signal transmission amplitude preset by the system, intended to prevent excessive transmission amplitude from damaging the equipment or causing inaccurate measurements. The next ultrasonic excitation signal is a new ultrasonic excitation signal generated according to the adjustment strategy after processing the current echo signal, which can be used for subsequent flow measurement.

[0116] In one possible implementation, if the average amplitude of the current echo signal does not meet a first preset condition, the amplification factor of the ultrasonic receiving circuit in the ultrasonic flowmeter or the transmission amplitude of the current ultrasonic excitation signal is adjusted based on the transmission amplitude of the current ultrasonic excitation signal and a preset maximum amplitude to obtain the next ultrasonic excitation signal, including:

[0117] Determine whether the current amplitude of the ultrasonic excitation signal is greater than the preset maximum amplitude.

[0118] If the current amplitude of the ultrasonic excitation signal is greater than the preset maximum amplitude, the amplification factor of the ultrasonic receiving circuit is adjusted, and then the amplitude of the current ultrasonic excitation signal is adjusted again to obtain the first and next ultrasonic excitation signals.

[0119] If the current ultrasonic excitation signal amplitude is less than or equal to the preset maximum amplitude, the current ultrasonic excitation signal amplitude is adjusted to obtain the next ultrasonic excitation signal.

[0120] Specifically, such as Figure 6 In the case where the average amplitude of the current echo signal does not meet the first preset condition, then... When the current ultrasonic excitation signal amplitude is greater than the preset maximum amplitude, the amplification factor of the ultrasonic receiving circuit is increased, and then the current ultrasonic excitation signal amplitude is adjusted to the minimum amplitude. If the current ultrasonic excitation signal amplitude is less than or equal to the preset maximum amplitude, the current ultrasonic excitation signal amplitude is directly increased. If the amplitude of the current ultrasonic excitation signal is greater than the preset maximum amplitude, the amplification factor of the ultrasonic receiving circuit is reduced, and then the amplitude of the current ultrasonic excitation signal is adjusted to the minimum amplitude. If the amplitude of the current ultrasonic excitation signal is less than or equal to the preset maximum amplitude, the amplitude of the current ultrasonic excitation signal is directly reduced. The purpose of these two processes is to ensure that the absolute value of (1 - (average of total amplitude / average of set amplitude)) is less than 0.1.

[0121] In one possible implementation, before calculating the similarity in overall shape between the echo waveform envelope and the spindle-shaped envelope of the current echo signal to obtain the cross-correlation value, given that the average amplitude of the current echo signal satisfies a first preset condition, the method includes:

[0122] Obtain the amplitude and position of multiple peaks in the echo waveform of the current echo signal.

[0123] The echo waveform envelope of the current echo signal is generated by plotting the fitting curve based on the amplitude and position of multiple peaks.

[0124] like Figure 7 As shown, Figure 7 This is a flowchart illustrating the process of generating the echo waveform envelope of an ultrasonic echo signal and determining the cross-correlation value, provided in an embodiment of this application. Figure 7 In the waveform, the position of the wave crest is the time point corresponding to the wave crest on the time axis of the echo waveform, i.e., the x-coordinate value corresponding to the peak. The position of the wave crest reflects the time information of the ultrasonic wave from emission to encountering a reflecting surface and being reflected back to be received, and is related to the position of the reflecting surface in the fluid and the propagation speed of the ultrasonic wave. The fitting curve is a curve that is as close as possible to these data points as possible, obtained by using certain mathematical methods (such as the least squares method) based on the given data points (i.e., the amplitude and position of multiple wave crests). The purpose of drawing this fitting curve is to smooth and summarize the discrete data points to more clearly present the overall trend of data change. Therefore, the drawn fitting curve is the echo waveform envelope of the current echo signal, which reflects the overall contour of the echo signal amplitude change over time.

[0125] It should be understood that generating the echo waveform envelope of the current echo signal by fitting a curve can eliminate local fluctuations between peaks and more accurately reflect the shape characteristics of the echo signal.

[0126] In one possible implementation, after determining that the average amplitude of the current echo signal satisfies a first preset condition, the method calculates the similarity in overall shape between the echo waveform envelope and the spindle-shaped envelope of the current echo signal, and obtains the cross-correlation value. The method then includes:

[0127] If the cross-correlation value is determined to be less than or equal to the first preset threshold, then according to the frequency adjustment rule, the current first transmission frequency value of the current ultrasonic excitation signal is adjusted to the second transmission frequency value to obtain the third next ultrasonic excitation signal; wherein, the second transmission frequency value is less than the first transmission frequency value.

[0128] like Figure 6 and Figure 7 As shown, if the cross-correlation value is less than or equal to the first preset threshold, it indicates that the echo waveform envelope of the current echo signal does not meet the expected shape requirements. Therefore, the current echo signal needs to be modulated to obtain an echo signal that meets the expected shape requirements. Specifically, according to the frequency adjustment rule, the currently used first transmission frequency value of the current ultrasonic excitation signal is adjusted to the second transmission frequency value, thereby obtaining the third next ultrasonic excitation signal (i.e., the newly generated ultrasonic excitation signal after adjustment). Here, the first transmission frequency value is the transmission frequency value of the current ultrasonic excitation signal, and the second transmission frequency value is the adjusted transmission frequency value, which is also the transmission frequency value of the third next ultrasonic excitation signal.

[0129] The frequency adjustment rule refers to the rules guiding how to adjust the transmission frequency of the ultrasonic excitation signal. In this embodiment, the frequency adjustment rule can be to fine-tune the transmission frequency of the test ultrasonic excitation signal corresponding to the test echo signal whose average amplitude of the echo waveform is second, based on the first transmission frequency value. After fine-tuning the current ultrasonic excitation signal according to the frequency adjustment rule, the finely-tuned ultrasonic excitation signal is transmitted again. Figure 6The cyclic process described herein continues until all conditions are met, i.e., the cross-correlation value between the echo waveform envelope and the spindle-shaped envelope of the finely tuned ultrasonic excitation signal is greater than a first preset threshold. At this point, the echo signal modulation process ends, and the transmission frequency of the finely tuned ultrasonic excitation signal is the second transmission frequency. The first transmission frequency value is the transmission frequency value of the test ultrasonic excitation signal corresponding to the first test echo signal, where the average amplitude of the echo waveform is the transmission frequency value of the test ultrasonic excitation signal corresponding to the first test echo signal. In other words, the two optimal transmission frequency values ​​corresponding to the optimal echo signal amplitude are: the average amplitude of the echo waveform being the transmission frequency value of the test ultrasonic excitation signal corresponding to the first test echo signal, and the average amplitude of the echo waveform being the transmission frequency value of the test ultrasonic excitation signal corresponding to the second test echo signal.

[0130] It should be understood that Figure 6 The echo signal modulation process aims to make the amplitude and waveform characteristics of the echo signal as close as possible to a preset target by continuously adjusting the amplitude of the transmitted signal and the amplification factor of the ultrasonic receiving circuit, thereby achieving the effect of echo signal modulation.

[0131] like Figure 8 As shown, Figure 8 This is a flowchart illustrating the process of determining the optimal transmission frequency value corresponding to the optimal amplitude of the echo signal, according to an embodiment of this application. Figure 8 In this process, after the ultrasonic flow meter system is powered on, the initial transmission amplitude of the ultrasonic excitation signal and seven different transmission frequencies are set. Then, the first set of ultrasonic excitation signals is transmitted, and the echo waveforms of the corresponding test echo signals are processed to obtain the average amplitude of this set of test echo signals. Next, the second set of ultrasonic excitation signals is transmitted, and the echo waveforms of the corresponding test echo signals are processed, until all seven transmission frequencies are scanned. If all seven frequencies are scanned, the average amplitude of the echo waveforms is recorded as the transmission frequency value of the ultrasonic excitation signal corresponding to the first test echo signal, and the average amplitude of the echo waveforms is recorded as the transmission frequency value of the ultrasonic excitation signal corresponding to the second test echo signal. Finally, the process ends. The entire process, by scanning different transmission frequencies, determines the two optimal transmission frequency values ​​that result in the optimal amplitude of the test echo signals. That is, the first optimal transmission frequency value is the average amplitude of the echo waveforms corresponding to the transmission frequency value of the ultrasonic excitation signal corresponding to the first test echo signal; the second optimal transmission frequency value is the average amplitude of the echo waveforms corresponding to the transmission frequency value of the ultrasonic excitation signal corresponding to the second test echo signal. It should be noted that in this embodiment, seven different transmission frequencies are set, but other numbers of different transmission frequencies can also be set according to application requirements.

[0132] In some examples, Figures 9-11This is a schematic diagram showing the experimental results of the influence of relevant parameters on the ultrasonic echo signal. Figure 9 This is a schematic diagram illustrating experimental results regarding the influence of the transmitted amplitude of an ultrasonic excitation signal on the ultrasonic echo signal, provided in an embodiment of this application. Figure 9 In the diagram, (9-a) represents the ultrasonic echo signal when the ultrasonic excitation signal has a transmission frequency of 2.33MHz and a transmission amplitude of 6.0V. Figure 9 (9-b) in the figure represents the ultrasonic echo signal when the ultrasonic excitation signal is emitted at a frequency of 2.33 MHz and an amplitude of 8.0 V. Figure 9 In the diagram, (9-c) represents the ultrasonic echo signal when the ultrasonic excitation signal has a transmission frequency of 2.33MHz and a transmission amplitude of 12.0V. Figure 9 In the equation (9-d), the ultrasonic echo signal is generated when the ultrasonic excitation signal has a transmission frequency of 2.33 MHz and a transmission amplitude of 16.0 V. Figure 9 In this experiment, when the transmission frequency of the ultrasonic excitation signal is 2.33MHz, it is considered the optimal transmission frequency. The magnitude of the transmission amplitude directly affects the received amplitude, but the overall envelope of the echo waveform remains spindle-shaped. Through experiments, it was found that when both the transmission frequency and amplitude are optimal (e.g.,...),... Figure 9 As shown in (9-b), the main body of the echo signal has a complete waveform in the middle, and the waveform frequency of the echo signal is close to the transmission frequency, showing obvious prominent features. This is beneficial for the subsequent time difference algorithm for extracting the echo signal and will not cause too much interference. When the amplitude of the echo signal is small, the amplitude of the middle part of the echo signal is similar to that of the two sides, and only a small part of the waveform frequency is close to the transmission frequency. This indicates that the remaining waveform is strongly attenuated by other factors, which will cause significant interference to the subsequent time difference acquisition algorithm. When the transmission amplitude is large (such as...), Figure 9 As shown in (9-d), the middle part begins to distort, and the integrity of the waveform cannot be guaranteed, which is not conducive to the calculation of subsequent algorithms. Figure 10 This is a schematic diagram illustrating experimental results regarding the influence of the transmission frequency of an ultrasonic excitation signal on the ultrasonic echo signal, provided in an embodiment of this application. Figure 10 In the diagram, (10-a) represents the ultrasonic echo signal when the amplitude of the ultrasonic excitation signal is 8.0V and the transmission frequency is 2.74MHz. Figure 10 In the diagram, (10-b) represents the ultrasonic echo signal when the ultrasonic excitation signal has an amplitude of 8.0V and a frequency of 2.53MHz. Figure 10 In the equation (10-c), the ultrasonic echo signal is generated when the amplitude of the ultrasonic excitation signal is 8.0V and the frequency is 2.33MHz. Figure 10 In the equation (10-d), the ultrasonic echo signal is generated when the amplitude of the ultrasonic excitation signal is 8.0V and the frequency is 2.17MHz. Figure 10 In the equation (10-e), the ultrasonic echo signal is generated when the amplitude of the ultrasonic excitation signal is 8.0V and the frequency is 2.04MHz. Figure 10 In the equation (10-f), the ultrasonic echo signal is generated when the amplitude of the ultrasonic excitation signal is 8.0V and the transmission frequency is 1.91MHz. Figure 10 In the case where the amplitude of the ultrasonic excitation signal is at its optimal value (i.e., the amplitude is 8.0V), the attenuation of the ultrasonic echo signal is more pronounced with different transmission frequencies. The frequency of the main part of the echo signal waveform is not uniform, the overall envelope of the echo waveform is not a spindle-shaped envelope, some waveform continuity is lost, and the subsequent time difference algorithm for extracting the echo signal cannot be performed. Figure 11 This is a schematic diagram illustrating experimental results regarding the influence of pipe diameter on ultrasonic echo signals, provided in an embodiment of this application. Figure 11 (11-a) in the figure represents the ultrasonic echo signal generated by the ultrasonic excitation signal in a UPVC pipe with a diameter of DN25. Figure 11 (11-b) in the figure represents the ultrasonic echo signal generated by the ultrasonic excitation signal in the UPVC pipe with a diameter of DN32. Figure 11 (11-c) in the figure represents the ultrasonic echo signal generated by the ultrasonic excitation signal in a PVC pipe with a diameter of DN25. Figure 11 In the test, two different pipe diameters (nominal diameter DN32 and nominal diameter DN25) and different pipe materials (rigid polyvinyl chloride UPVC and polyvinyl chloride PVC) were tested. The received echo signals were generally similar. Different pipe materials had different absorption and reflection of ultrasonic waves, resulting in different echo signal tails, but the main trend of the echo signals was basically consistent.

[0133] It is understood that the ultrasonic flow meter provided in this application embodiment can modulate the echo signal, and has the following advantages compared with existing ultrasonic flow meters:

[0134] (1) Existing ultrasonic flow meters can only measure a single type of liquid medium, and a single sensor can only measure a few fixed liquid media; however, the ultrasonic flow meter provided in this application can enhance sound transmission and be compatible with more fluid media by changing the emission frequency and amplitude of ultrasonic waves.

[0135] (2) Existing ultrasonic flow meters have high requirements for the flow state of the liquid being measured, and a small amount of bubbles and small solid particles have a significant impact on the results; however, the ultrasonic flow meter provided in this application can enhance sound transmission by changing the emission frequency and amplitude of the ultrasonic waves, thereby greatly reducing interference with the results.

[0136] (3) Existing ultrasonic flow meters have strict requirements on the pipe wall material being measured and cannot measure pipes with weak sound transmission. However, the ultrasonic flow meter provided in this application enhances the strength of the echo signal by changing the emission amplitude and the amplification factor of the receiving circuit, and is compatible with more pipes.

[0137] (4) Existing ultrasonic flow meters do not have many requirements for the quality of echo signals, or the waveform only needs to conform to the spindle shape in the experimental environment. However, after experiments, it was found that when the running time increases, some states of the fluid change, which affects the echo and ultimately has a great impact on the results. The ultrasonic flow meter provided in this application continuously modifies the parameters of the transmitted waveform by periodically detecting the echo signal.

[0138] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0139] A modulation method for an ultrasonic echo signal corresponding to the above embodiment, Figure 12 The diagram shows a schematic of an ultrasonic echo signal modulation device according to an embodiment of this application. For ease of explanation, only the parts related to the embodiment of this application are shown.

[0140] Reference Figure 12 The ultrasonic echo signal modulation device 6 in this embodiment includes:

[0141] The signal acquisition module 61 is used to acquire the current echo signal corresponding to the current ultrasonic excitation signal emitted by the ultrasonic flow meter to the target fluid.

[0142] The amplitude calculation module 62 is used to calculate the amplitude of multiple peaks in the echo waveform of the current echo signal to obtain the average amplitude of the current echo signal.

[0143] The first determining module 63 is used to calculate the degree of similarity in overall shape between the echo waveform envelope and the spindle-shaped envelope of the current echo signal, provided that the average amplitude of the current echo signal meets a first preset condition, and to obtain a cross-correlation value. The first preset condition indicates that the deviation between the average amplitude and the preset expected average amplitude is within a preset error range.

[0144] The second determining module 64 is used to calculate the flow rate data of the target fluid based on the specified echo signal determined based on the current ultrasonic excitation signal when the cross-correlation value is determined to be greater than the first preset threshold.

[0145] It should be noted that the information interaction and execution process between the modules in the above-mentioned ultrasonic echo signal modulation device 6 are based on the same concept as the method embodiment of this application. For details on their specific functions and technical effects, please refer to the method embodiment section, and they will not be repeated here.

[0146] This application also provides a terminal device, such as... Figure 13 As shown, Figure 13 This is a schematic diagram of the structure of a terminal device provided in an embodiment of this application. (Refer to...) Figure 13 The terminal device 7 in this embodiment includes a memory 71, a processor 72, and a computer program stored in the memory 71 and executable on the processor 72. When the processor 72 executes the computer program, it implements the steps in the above-described ultrasonic echo signal modulation method embodiment.

[0147] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps described in the various method embodiments above.

[0148] This application provides a computer program product that, when run on a mobile terminal, enables the mobile terminal to implement the steps described in the above-described method embodiments.

[0149] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. A computer-readable medium can include at least: any entity or device capable of carrying computer program code to a photographic device / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0150] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0151] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0152] In the embodiments provided in this application, it should be understood that the disclosed apparatus / network devices and methods can be implemented in other ways. For example, the apparatus / network device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0153] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0154] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method of modulating an ultrasonic echo signal, characterized by, The method comprises the following steps: acquiring a current echo signal corresponding to a current ultrasonic excitation signal emitted by an ultrasonic flowmeter to a target fluid; calculating the amplitudes of multiple wave crests in the echo waveform of the current echo signal to obtain an amplitude average value of the current echo signal; in a case where it is determined that the amplitude average value of the current echo signal does not satisfy a first preset condition, adjusting the amplification multiple of an ultrasonic receiving circuit in the ultrasonic flowmeter or adjusting the emission amplitude of the current ultrasonic excitation signal according to the emission amplitude of the current ultrasonic excitation signal and a preset maximum amplitude to obtain a next ultrasonic excitation signal; in a case where it is determined that the amplitude average value of the current echo signal satisfies the first preset condition, calculating the similarity degree in overall shape between the envelope line of the echo waveform of the current echo signal and a spindle envelope line to obtain a cross-correlation value; wherein the first preset condition is used to represent that the deviation value between the amplitude average value and a preset expected amplitude average value is within a preset error range; in a case where it is determined that the cross-correlation value is greater than a first preset threshold value, calculating the flow data of the target fluid according to a specified echo signal determined based on the current ultrasonic excitation signal; if it is determined that the cross-correlation value is less than or equal to the first preset threshold value, then adjusting the first emission frequency value currently adopted by the current ultrasonic excitation signal to a second emission frequency value according to a frequency adjustment rule to obtain a third next ultrasonic excitation signal; wherein the second emission frequency value is less than the first emission frequency value.

2. The method of claim 1, wherein the ultrasonic echo signal is modulated by a frequency of 40 kHz or more. The method of adjusting the amplification multiple of the ultrasonic receiving circuit in the ultrasonic flowmeter or adjusting the emission amplitude of the current ultrasonic excitation signal according to the emission amplitude of the current ultrasonic excitation signal and a preset maximum amplitude to obtain a next ultrasonic excitation signal in a case where it is determined that the amplitude average value of the current echo signal does not satisfy the first preset condition comprises the following steps: judging whether the emission amplitude of the current ultrasonic excitation signal is greater than the preset maximum amplitude; if the emission amplitude of the current ultrasonic excitation signal is greater than the preset maximum amplitude, then adjusting the emission amplitude of the current ultrasonic excitation signal after adjusting the amplification multiple of the ultrasonic receiving circuit to obtain a first next ultrasonic excitation signal; if the emission amplitude of the current ultrasonic excitation signal is less than or equal to the preset maximum amplitude, then adjusting the emission amplitude of the current ultrasonic excitation signal to obtain a second next ultrasonic excitation signal.

3. The method of claim 1, wherein the ultrasonic echo signal is modulated by a frequency of 40 kHz or more. The method of calculating the amplitudes of multiple wave crests in the echo waveform of the current echo signal to obtain the amplitude average value of the current echo signal comprises the following steps: acquiring the amplitude of each wave crest in the multiple wave crests; judging whether the amplitude of each wave crest is greater than a preset minimum wave crest amplitude; taking the wave crest with an amplitude greater than the preset minimum wave crest amplitude as a target wave crest; accumulating the amplitudes of multiple target wave crests to obtain a total amplitude value of the multiple wave crests; calculating the average value of the total amplitude value of the multiple wave crests to obtain the amplitude average value of the current echo signal.

4. The method of claim 1, wherein the ultrasonic echo signal is modulated by a frequency of 40 kHz or more. Before the calculating the similarity degree between the echo waveform envelope line and the spindle envelope line of the current echo signal in overall shape to obtain a cross-correlation value in the case that the amplitude average value of the current echo signal meets a first preset condition, the method comprises: Obtaining the amplitudes of a plurality of wave crests in the echo waveform of the current echo signal and the positions of the plurality of wave crests; Drawing a fitting curve according to the amplitudes of the plurality of wave crests and the positions of the plurality of wave crests to generate the echo waveform envelope line of the current echo signal.

5. The method of modulating an ultrasonic echo signal according to any one of claims 1 to 4, wherein, The method comprises: Generating a current ultrasonic pulse signal and a current analog voltage signal through a main control module in the ultrasonic flowmeter; Performing signal synthesis processing on the current ultrasonic pulse signal and the current analog voltage signal based on an ultrasonic transmitting module in the ultrasonic flowmeter to generate the current ultrasonic excitation signal; Sending the current ultrasonic excitation signal to a first transducer in the ultrasonic flowmeter through the ultrasonic transmitting module; Converting the current ultrasonic excitation signal into a current ultrasonic vibration signal through the first transducer, so that a second transducer in the ultrasonic flowmeter receives the current ultrasonic vibration signal and converts the current ultrasonic vibration signal into an initial echo signal; Collecting the initial echo signal converted by the second transducer through an ultrasonic receiving module in the ultrasonic flowmeter, and amplifying the initial echo signal through an ultrasonic receiving circuit in the ultrasonic receiving module to obtain the current echo signal corresponding to the current ultrasonic excitation signal.

6. The method of modulating an ultrasonic echo signal according to claim 5, wherein, The method comprises: Increasing the voltage amplitude of the current analog voltage signal through a boost circuit in the ultrasonic transmitting module to obtain a boosted analog signal corresponding to the current analog voltage signal; Increasing the amplitude of the current ultrasonic pulse signal through a pulse signal amplification circuit in the ultrasonic transmitting module to obtain an amplified ultrasonic pulse signal corresponding to the current ultrasonic pulse signal; Performing synthesis processing on the boosted analog signal and the amplified ultrasonic pulse signal through the pulse signal amplification circuit to obtain the current ultrasonic excitation signal.

7. An ultrasonic flow meter characterized by, The method comprises: A main control module, an ultrasonic transmitting module, an ultrasonic receiving module, a first transducer, and a second transducer, wherein The main control module is connected with the ultrasonic transmitting module and the ultrasonic receiving module respectively, and is configured to generate an ultrasonic pulse signal and an analog voltage signal, and send the ultrasonic pulse signal and the analog voltage signal to the ultrasonic transmitting module. The ultrasonic wave transmitting module is connected with the first transducer, and is used for signal synthesis processing on the ultrasonic wave pulse signal and the analog voltage signal, generating an ultrasonic wave excitation signal, and sending the ultrasonic wave excitation signal to the first transducer; The first transducer is used for converting the ultrasonic wave excitation signal into an ultrasonic wave vibration signal, and emitting the ultrasonic wave vibration signal to a target fluid, so that the second transducer receives the ultrasonic wave vibration signal and converts the ultrasonic wave vibration signal into an initial echo signal; The ultrasonic wave receiving module is connected with the second transducer, and is used for collecting the initial echo signal converted by the second transducer, amplifying the initial echo signal through an ultrasonic wave receiving circuit, outputting an echo signal, and sending the echo signal to the main control module; The main control module is also used for executing the modulation method of the ultrasonic wave echo signal as in any one of claims 1 to 6.

8. A computer program product, characterised in that, The computer program is run to execute the method as in any one of claims 1 to 6.

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