Ultrasonic echo signal modulation method and ultrasonic flowmeter

Abstract

The invention is suitable for the technical field of ultrasonic flow detection, and provides an ultrasonic echo signal modulation method and an ultrasonic flowmeter, and the method comprises the following steps: obtaining a current echo signal corresponding to a current ultrasonic excitation signal emitted by the ultrasonic flowmeter to a target fluid; and calculating the amplitudes of a plurality of wave crests in the echo waveform of the current echo signal to obtain an amplitude average value of the current echo signal. Under the condition that it is determined that the amplitude average value of the current echo signal meets the first preset condition, the similarity degree of the echo waveform envelope line and the spindle-shaped envelope line of the current echo signal in the overall shape is calculated, and a cross correlation degree value is obtained. And when it is determined that the cross correlation degree value is larger than a first preset threshold value, flow data of the target fluid are calculated according to a specified echo signal determined based on the current ultrasonic excitation signal. According to the method, the echo signal has better stability in the operation process, and the measurement precision of the ultrasonic flowmeter is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of ultrasonic flow detection, and in particular relates to a modulation method of an ultrasonic echo signal and an ultrasonic flowmeter. Background Art

[0002] Currently, ultrasonic flow meters utilize the propagation characteristics of ultrasonic waves in fluids. There is no need to cut the pipe or contact the fluid. The fluid flow rate can be measured by directly clamping the transducer on the outer wall of the pipe.

[0003] According to the measurement principle of ultrasonic flowmeters, achieving higher accuracy and repeatability requires that the echo signal waveform conform to a spindle-like shape during measurement, that the echo signal strength remain consistent throughout each run, and that the overall echo shape does not significantly change. However, extensive testing has shown that as ultrasonic flowmeters operate longer, both the meter itself and the environment can affect the echo signal. This can lead to weakening of the echo signal strength and deformation of the overall shape, resulting in poor measurement accuracy. Summary of the Invention

[0004] The embodiments of the present application provide a modulation method for an ultrasonic echo signal and an ultrasonic flowmeter, which can solve the technical problem that the existing ultrasonic flowmeter has low measurement accuracy due to the weakening of echo signal intensity and shape deformation during long-term operation.

[0005] In a first aspect, an embodiment of the present application provides a method for modulating an ultrasonic echo signal, comprising: Obtaining a current echo signal corresponding to a current ultrasonic excitation signal emitted by the ultrasonic flowmeter to the target fluid; Calculating the amplitudes of multiple peaks in the echo waveform of the current echo signal to obtain an amplitude average of the current echo signal; When it is determined that the amplitude average value of the current echo signal satisfies a first preset condition, calculating the degree of similarity between the overall shape of the echo waveform envelope of the current echo signal and the spindle-shaped envelope to obtain a cross-correlation value; wherein the first preset condition is used to indicate that a deviation between the amplitude average value and a preset expected amplitude average value is within a preset error range; When it is determined that the cross-correlation value is greater than a first preset threshold, the flow data of the target fluid is calculated according to a designated echo signal determined based on the current ultrasonic excitation signal.

[0006] In a second aspect, an embodiment of the present application provides a modulation device for an ultrasonic echo signal, comprising: The signal acquisition module is configured to acquire a current echo signal corresponding to a current ultrasonic excitation signal emitted by the ultrasonic flowmeter to the target fluid. The amplitude calculation module is configured to calculate amplitudes of a plurality of wave crests in an echo waveform of the current echo signal to obtain an amplitude average value of the current echo signal. The first determination module is configured to, in a case where the amplitude average value of the current echo signal meets a first preset condition, calculate a similarity degree between an echo waveform envelope of the current echo signal and a spindle envelope in an overall shape to obtain a cross-correlation degree value, wherein the first preset condition is used to represent that a deviation value between the amplitude average value and a preset expected amplitude average value is within a preset error range. The second determination module is configured to, in a case where the cross-correlation degree value is greater than a first preset threshold, calculate flow data of the target fluid according to a specified echo signal determined based on the current ultrasonic excitation signal.

[0007] In a third aspect, an ultrasonic flowmeter is provided, comprising: 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 transmitting module is connected with the first transducer, and is configured 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. The first transducer is configured to convert the ultrasonic excitation signal into an ultrasonic vibration signal, emit the ultrasonic vibration signal to a target fluid, propagate the ultrasonic vibration signal 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. The ultrasonic receiving module is connected with the second transducer, and is configured to collect the initial echo signal converted by the second transducer, amplify the initial echo signal through an ultrasonic receiving circuit, output an echo signal, and send the echo signal to the main control module. The main control module is further configured to perform the ultrasonic echo signal modulation method according to any one of the first aspect.

[0008] In a fourth aspect, an embodiment of the present application provides a terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the modulation method of the ultrasonic echo signal described in any one of the above items when executing the computer program.

[0009] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the modulation method of the ultrasonic echo signal described in any one of the above items is implemented.

[0010] In a sixth aspect, an embodiment of the present application provides a computer program product, which, when executed on a terminal device, enables the terminal device to execute the method for modulating an ultrasonic echo signal as described in any one of the first aspects above.

[0011] Compared with the prior art, the embodiments of the present application have the following beneficial effects: An embodiment of the present application provides a method for modulating an ultrasonic echo signal, comprising: obtaining a current echo signal corresponding to a current ultrasonic excitation signal emitted by an ultrasonic flowmeter toward a target fluid; calculating the amplitudes of multiple peaks in the echo waveform of the current echo signal to obtain an average amplitude value of the current echo signal; then, if it is determined that the average amplitude value of the current echo signal satisfies a first preset condition, calculating the degree of similarity between the overall shape of the echo waveform envelope of the current echo signal and a spindle-shaped envelope to obtain a cross-correlation value. The first preset condition indicates that the deviation between the average amplitude value and a preset expected average amplitude value is within a preset error range. Finally, if it is determined that the cross-correlation value is greater than a first preset threshold, calculating flow rate data of the target fluid based on a designated echo signal determined based on the current ultrasonic excitation signal. This method periodically monitors the amplitude and shape of the echo signal and adjusts the frequency and amplitude of the ultrasonic excitation signal based on the amplitude and shape of the echo signal, thereby improving the stability of the echo signal during operation and the measurement accuracy of the ultrasonic flowmeter. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0013] Figure 1 This is a structural diagram of an ultrasonic flowmeter provided in one embodiment of the present application; Figure 2is a method flowchart provided by an embodiment of the present application about ultrasonic wave excitation signal synthesis; Figure 3 is a schematic diagram of an ultrasonic wave receiving circuit provided by an embodiment of the present application; Figure 4 is a flowchart of a modulation method of an ultrasonic wave echo signal provided by an embodiment of the present application; Figure 5 is a calculation process schematic diagram of an average value of a current echo signal amplitude provided by an embodiment of the present application; Figure 6 is a flowchart of a modulation method of an ultrasonic wave echo signal provided by another embodiment of the present application; Figure 7 is a flowchart of a generation process of an echo waveform envelope of an ultrasonic wave echo signal and a judgment process of a cross-correlation value provided by an embodiment of the present application; Figure 8 is a flowchart of a determination process of a best transmission frequency value corresponding to an optimal echo signal amplitude provided by an embodiment of the present application; Figure 9 is an experimental result schematic diagram of an influence of a transmission amplitude of an ultrasonic wave excitation signal on an ultrasonic wave echo signal provided by an embodiment of the present application; Figure 10 is an experimental result schematic diagram of an influence of a transmission frequency of an ultrasonic wave excitation signal on an ultrasonic wave echo signal provided by an embodiment of the present application; Figure 11 is an experimental result schematic diagram of an influence of a pipe diameter on an ultrasonic wave echo signal provided by an embodiment of the present application; Figure 12 is a structural schematic diagram of a modulation device of an ultrasonic wave echo signal provided by an embodiment of the present application; Figure 13 is a structural schematic diagram of a terminal device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0014] In the following description, specific details are set forth, such as particular system configurations, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. However, persons skilled in the art will understand that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

[0015] It should be understood that the word “comprise” or variations such as “comprises” or “comprising”, when used in this specification and in the accompanying claims, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0016] It should also be understood that the term “and / or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items, and that the term “at least one of’ denotes one, or a combination of two or more items.

[0017] As used in this specification and in the appended claims, the term “if’ can be interpreted as meaning “when” or “once” or “in response to a determination” or “in response to a detection” depending on the context. Similarly, the phrase “if it is determined” or “if [a described condition or event] is detected” can be interpreted as meaning “once it is determined” or “in response to a determination” or “once [the described condition or event] is detected” or “in response to a detection of [the described condition or event]” depending on the context.

[0018] In addition, in the description of the application in the specification and the appended claims, the terms “first”, “second”, “third”, etc. are used only for distinguishing descriptions, and cannot be understood as indicating or implying relative importance.

[0019] Reference in the specification to “one embodiment” or “some embodiments” or “an embodiment” or “some implementations” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrases “in one embodiment”, “in some embodiments”, “in other embodiments”, “in additional embodiments” or the like in various places in the specification are not necessarily all referring to the same embodiment, unless otherwise specifically stated. The terms “comprise”, “comprises”, “comprising”, “include”, “includes”, “including” and variations thereof are meant to encompass the items listed thereafter, but do not exclude the presence of one or more other items.

[0020] An ultrasonic flowmeter is an instrument for measuring the flow rate of a fluid (liquid or gas), which utilizes the propagation characteristics of ultrasonic waves in the fluid, without cutting the pipeline or contacting the fluid, and can achieve measurement of the fluid by directly clamping a transducer on the outer wall of the pipeline. The development of ultrasonic flowmeters benefits from the maturity of piezoelectric ceramic materials, precise electronic timing technology, and digital signal processing technology, which makes it possible to accurately extract weak ultrasonic signals from complex noise backgrounds and calculate small time differences, thereby solving the problems of complex installation and maintenance of traditional flowmeters, pressure loss, and wear of moving parts.

[0021] The core measurement principle of the ultrasonic flowmeter is the time difference method of ultrasonic wave propagation. Two sensors are used alternately as the transmitter and receiver. The ultrasonic wave propagates faster in the direction of fluid flow and slower in the opposite direction. The difference between the time of ultrasonic wave propagation in the upstream and downstream directions is accurately measured by the instrument. This time difference is proportional to the average flow rate of the fluid. Combined with the known pipe diameter, sound channel length, sound channel angle, and the fluid sound velocity obtained by measurement, the flow rate and flow of the fluid can be calculated. As shown in the following formula: ; ; In the formula, is the time of ultrasonic wave propagation in the upstream direction; is the time of ultrasonic wave propagation in the downstream direction; is the propagation distance of ultrasonic wave in the liquid; is the sound velocity of ultrasonic wave propagation in the fluid; is the flow rate of the fluid; According to the above formula, we can get: ; In the formula, is the time difference, .

[0022] As can be seen from the formula, to make the flowmeter have higher accuracy and repeatability, the accuracy of , , must be ensured, and the time difference is usually obtained by the phase method and the cross-correlation method. These two methods do not have too much requirement on the overall shape of the echo waveform, but , are obtained by the threshold method, the envelope method, the zero-point detection method, etc. These methods require the echo signal to have a shape similar to a spindle, and the signal strength of the echo signal must be consistent during each operation, and the overall echo shape must not be deformed too much. However, through a large number of tests, it is found that as the ultrasonic flowmeter runs for a long time, the flowmeter itself or the environment will have some impact on the echo signal, such as weakening of the echo signal strength, deformation of the overall shape, etc.

[0023] The application provides an echo signal modulation method of an ultrasonic flowmeter, which can monitor the amplitude and shape of the echo signal periodically, change the frequency and amplitude of the excitation signal provided to the transducer, and change the amplification of the receiving circuit, so that the echo signal has better stability during operation, and the accuracy and repeatability of the flowmeter are improved. In addition, the method can still monitor and modulate the echo signal in different liquids and pipes, so that the strength and shape of the echo signal meet the set value, and the ultrasonic flowmeter can be compatible with more liquids and pipes that can transmit sound, and can more accurately measure the flow rate and flow in different liquids or pipes.

[0024] Please refer to Figure 1 , Figure 1 is a structural schematic diagram of an ultrasonic flowmeter provided by an embodiment of the application. The ultrasonic flowmeter 1 comprises a main control module 10, an ultrasonic transmitting module 20, an ultrasonic receiving module 30, a first transducer 40 and a second transducer 50.

[0025] The main control module 10 is connected with the ultrasonic transmitting module 20 and the ultrasonic receiving module 30 respectively, and is used for generating ultrasonic pulse signals and analog voltage signals, and sending the ultrasonic pulse signals and the analog voltage signals to the ultrasonic transmitting module 20.

[0026] The ultrasonic transmitting module 20 is connected with the first transducer 40, and is used for performing signal synthesis processing on the ultrasonic pulse signals and the analog voltage signals, generating ultrasonic excitation signals, and sending the ultrasonic excitation signals to the first transducer 40.

[0027] The first transducer 40 is used for converting the ultrasonic excitation signals into ultrasonic vibration signals, emitting the ultrasonic vibration signals to a target fluid, propagating the ultrasonic vibration signals through the target fluid as a propagation carrier, so that the second transducer receives the ultrasonic vibration signals, and converts the ultrasonic vibration signals into initial echo signals.

[0028] The ultrasonic receiving module 30 is connected with the second transducer 50, and is used for collecting the initial echo signals converted by the second transducer 50, amplifying the initial echo signals through an ultrasonic receiving circuit, outputting echo signals, and sending the echo signals to the main control module 10.

[0029] The main control module 10 is also used for executing an ultrasonic echo signal modulation method.

[0030] As shown in Figure 1 , the ultrasonic flowmeter 1 comprises the main control module 10, the ultrasonic transmitting module 20, the ultrasonic receiving module 30, the first transducer 40 and the second transducer 50.

[0031] The main control module 10 is a core control component of the ultrasonic flowmeter 1, and is mainly used for generating ultrasonic pulse signals and analog voltage signals, and sending the signals to the ultrasonic transmitting module 20; meanwhile, the main control module 10 can also receive echo signals returned by the ultrasonic receiving module, modulate the echo signals to obtain specified echo signals, and comprehensively control and process data of the measurement of the flowmeter.

[0032] The ultrasonic transmitting module 20 is connected with the main control module 10 and the first transducer 40. The ultrasonic transmitting module 20 is mainly used for performing signal synthesis processing on the ultrasonic pulse signals and the analog voltage signals received from the main control module 10, generating ultrasonic excitation signals capable of driving the first transducer 40 to work, and then sending the ultrasonic excitation signals to the first transducer 40.

[0033] As shown in Figure 2 , the method for synthesizing the ultrasonic excitation signals is provided in an embodiment of the present application, and a flowchart of the method is shown in Figure 2 . As shown in Figure 2 , the specific process of the ultrasonic transmitting module 20 for performing signal synthesis processing on the ultrasonic pulse signals and the analog voltage signals is as follows: through the boost circuit 21 in the ultrasonic transmitting module 20, the voltage amplitude of the analog voltage signal generated by the main control module 10 is increased to obtain a boost analog signal corresponding to the analog signal; meanwhile, through the pulse signal amplification circuit 22 in the ultrasonic transmitting module 20, the amplitude of the ultrasonic pulse signal is increased to obtain an amplified ultrasonic pulse signal corresponding to the ultrasonic pulse signal. Finally, through the pulse signal amplification circuit 22, the boost analog signal and the amplified ultrasonic pulse signal are synthesized to obtain the ultrasonic excitation signal.

[0034] The main control module 10 mainly generates two key signals: an analog voltage signal and an ultrasonic pulse signal. The analog voltage signal is an analog signal generated according to a pre-set excitation signal amplitude, used to control the amplitude of the ultrasonic excitation signal, while the ultrasonic pulse signal is used to adjust the pulse characteristics of the ultrasonic excitation signal, such as pulse width, frequency, etc. After the analog voltage signal is output from the main control module 10, it will enter the boost circuit 21. The main function of the boost circuit 21 is to raise the voltage amplitude of the analog voltage signal to a suitable amplitude. Because the analog signal voltage converted by the digital-to-analog converter is usually low and cannot directly drive the subsequent transducer and other loads, the voltage amplitude of the analog voltage signal needs to be raised to obtain a boosted analog signal to drive the subsequent first transducer 40 to work. After the ultrasonic pulse signal is output from the main control module 10, it will enter the pulse signal amplitude increasing circuit 22, which can increase the amplitude of the ultrasonic pulse signal to generate a corresponding amplified ultrasonic pulse signal. The analog voltage signal after boost processing (boosted analog signal) and the ultrasonic pulse signal after amplitude processing (amplified ultrasonic pulse signal) are combined into an ultrasonic excitation signal in the pulse signal amplitude increasing circuit 22. The function of the pulse signal amplitude increasing circuit 22 is to enhance the amplitude of the ultrasonic pulse signal while maintaining the integrity of the pulse shape of the ultrasonic pulse signal. Finally, the ultrasonic excitation signal is input into the first transducer 40, which converts the electrical signal into a mechanical vibration signal (i.e. ultrasonic vibration signal), thereby generating ultrasonic waves.

[0035] The first transducer 40 is one of the key components for converting electrical signals and ultrasonic vibration signals in the ultrasonic flowmeter 1. The first transducer 40 is connected with the ultrasonic transmitting module 20, receives the ultrasonic excitation signal sent by the ultrasonic transmitting module 20, and converts the ultrasonic excitation signal into an ultrasonic vibration signal. The ultrasonic vibration signal is emitted to the target fluid, so that the ultrasonic vibration signal propagates through the target fluid as a propagation carrier, 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 form of ultrasonic waves in the fluid, and when encountering various conditions in the fluid (such as fluid flow, interface, etc.), it will reflect and form a signal that can be used to measure flow information. The second transducer 50 is another transducing component in the ultrasonic flowmeter 1. The second transducer 50 is connected with the ultrasonic receiving module 30, can receive the ultrasonic vibration signal emitted by the first transducer 40, and converts the ultrasonic vibration signal into an initial echo signal. The initial echo signal is an electrical signal converted from the ultrasonic vibration signal.

[0036] It should be noted that in the ultrasonic flowmeter 1 in the embodiment, the specific position arrangement of the first transducer 40 and the second transducer 50 depends on the type of the flowmeter. Common types of ultrasonic flowmeters include outside clamp-on, inside insert, etc. For example, in an outside clamp-on ultrasonic flowmeter, the two transducers are usually mounted on the outer wall of the fluid pipe, and they are generally arranged in a certain angle (in the flow direction or the reverse flow direction) on the same side or different sides of the pipe. In an inside insert ultrasonic flowmeter, the transducers are directly inserted into the inside of the fluid pipe through a special probe, and they can be mounted on the same cross section of the fluid pipe and arranged in a certain angle, or inserted at different positions.

[0037] The ultrasonic receiving module 30 is connected with the second transducer 50 and the main control module 10, can collect the initial echo signal converted by the second transducer 50, and amplify the initial echo signal through the ultrasonic receiving circuit to output the corresponding echo signal, and finally send the echo signal to the main control module 10, so that the main control module 10 modulates the echo signal to obtain the specified echo signal. Because the ultrasonic vibration signal may be attenuated during transmission and conversion, the initial echo signal at this time may be weak and needs to be further amplified. The ultrasonic receiving circuit is a circuit for receiving the initial echo signal converted by the second transducer and amplifying the initial echo signal. The echo signal is the signal output after the initial echo signal is amplified. The echo signal is stronger and more suitable for analysis and processing by the main control module 10 to extract information about the fluid flow.

[0038] As shown in Figure 3 , Figure 3 is a schematic diagram of an ultrasonic receiving circuit provided by an embodiment of the present application. The ultrasonic receiving circuit can amplify the initial echo signal. As shown in Figure 3In the present embodiment, the ultrasonic receiving circuit is a double-channel adjustable gain inverting amplification circuit, which is composed of two operational amplifiers, a plurality of resistors and two switches. The negative input end 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 end of the first operational amplifier 31 is connected to the input end of the second resistor R2 and the output end of the third resistor R3, and the output end of the first resistor R1 is also connected to the input end of the third resistor R3. The third resistor R3 and the fourth resistor R4 are controlled by the first switch 32 to determine whether to be connected in parallel through the first transistor 33, when the first switch 32 is closed, the third resistor R3 and the fourth resistor R4 are connected in parallel, the positive electrode VCC and the negative electrode GND (also called the ground end) of the power supply supply power for the first operational amplifier 31, at the same time, the power supply of VCC / 2 is connected to the positive input end of the first operational amplifier 31 to provide a bias voltage for the first operational amplifier 31. Correspondingly, the negative input end of the second operational amplifier 34 is connected to the output end of the second resistor R2, the output end of the second operational amplifier 34 is connected to the output end of the fifth resistor R5 and the output end of the sixth resistor R6, the fifth resistor R5 and the sixth resistor R6 are controlled by the second switch 35 to determine whether to be connected in parallel through the second transistor 36, when the second switch 35 is closed, the fifth resistor R5 and the sixth resistor R6 are connected in parallel, the positive electrode VCC and the negative electrode GND of the power supply supply power for the second operational amplifier 34, in addition, the power supply of VCC / 2 is also connected to the positive input end 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 end of the second operational amplifier 34.

[0039] When the first switch 32 and the second switch 35 are open, the connection mode of the third resistor R3 and the fourth resistor R4 and the fifth resistor R5 and the sixth resistor R6 will be changed from parallel to open, which will adjust the resistance of the feedback resistor and change the gain of the first operational amplifier 31 and the second operational amplifier 34. For example, in the first operational amplifier 31 part, when the first switch 32 is open, the fourth resistor R4 is open, and the feedback resistor is only determined by the third resistor R3, which causes the amplification factor to change. Similarly, in the second operational amplifier 34 part, when the second switch 35 is open, the sixth resistor R6 is open, and the feedback resistor is only determined by the fifth resistor R5. Through this design, the ultrasonic receiving circuit can flexibly switch the amplification factor. When a larger amplification factor is needed, the first switch 32 or the second switch 35 can be placed in a position that makes the feedback resistor smaller (i.e., open the parallel resistor fourth resistor R4 or sixth resistor R6); on the contrary, when a smaller amplification factor is needed, the parallel resistor (i.e., the fourth resistor R4 or the sixth resistor R6) can be closed to increase the resistance 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 designing a reasonable resistance value of the feedback resistor, four programmable amplification factors can be provided, i.e., the first switch 32 and the second switch 35 are both closed; the first switch 32 and the second switch 35 are both open; the first switch 32 is closed and the second switch 35 is open; the first switch 32 is open and the second switch 35 is closed.

[0040] Specifically, in the present embodiment, during the process in which the ultrasonic flowmeter 1 measures the flow rate of the target fluid, the main control module 10 can generate a basic ultrasonic pulse signal and an analog voltage signal, and then send the ultrasonic pulse signal and the analog voltage signal to the ultrasonic transmitting module 20. The ultrasonic transmitting module 20 can amplify the ultrasonic pulse signal and the analog voltage signal sent by the main control module 10 by a certain multiple, output an ultrasonic excitation signal, and send the ultrasonic excitation signal to the first transducer 40. The first transducer 40 converts the ultrasonic excitation signal into an ultrasonic vibration signal, which propagates to the second transducer 50 with the target fluid medium as the propagation carrier, so that the second transducer 50 receives 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 collects the initial echo signal converted by the second transducer 50, amplifies the initial echo signal by a certain amplification multiple of the ultrasonic receiving circuit, and then outputs the echo signal corresponding to the ultrasonic excitation signal, and transmits the echo signal to the main control module 10. After the main control module 10 collects the complete echo signal, the main control module 10 processes the echo signal through a specific algorithm, extracts the related parameters of the echo signal, and then modulates the echo signal until the extracted parameters meet the set values of the algorithm, that is, the modulation of the ultrasonic echo signal is completed. After obtaining the modulated ultrasonic echo signal, the flow rate data of the target fluid is calculated according to the ultrasonic echo signal.

[0041] It should be noted that the ultrasonic flowmeter provided by the embodiments of the present application can be applied to the flow control of high-purity cooling water, corrosive chemical reagents (such as a medium containing hydrogen fluoride acid), and the like; can also be used to measure various water flow rates (such as cooling water, drinking water, neutral water, and the like); can also be used for flow rate monitoring in extreme environments (such as high temperature, low temperature, and radiation); can also be applied to medical treatment, laboratory, and the like to accurately measure small flow rates; and can also be used for flow rate measurement of corrosive liquids such as industrial sewage.

[0042] Please refer to Figure 4 , Figure 4 is a flowchart of a modulation method of an ultrasonic echo signal provided by an embodiment of the present application. The method comprises: S11, obtaining a current echo signal corresponding to a current ultrasonic excitation signal emitted by an ultrasonic flowmeter to a target fluid.

[0043] S12, calculating the amplitude values of a plurality of wave peaks in the echo waveform of the current echo signal to obtain an amplitude average value of the current echo signal.

[0044] S13, in the case where it is determined that the amplitude average value of the current echo signal satisfies a first preset condition, calculating a similarity degree between an echo waveform envelope line and a spindle envelope line of the current echo signal in overall shape to obtain a cross-correlation degree value. The first preset condition is used to represent that a deviation value between the amplitude average value and a preset expected amplitude average value is within a preset error range.

[0045] S14, in the case where it is determined that the cross-correlation degree 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.

[0046] It should be noted that the method can be applied to the measurement of fluid flow by an ultrasonic flowmeter.

[0047] The target fluid is a fluid medium whose flow needs to be measured. The target fluid can be a liquid (such as water, oil, etc.) or a gas (such as air, natural gas, etc.), and 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 flowmeter to the target fluid for exciting ultrasonic vibration. The signal is converted into an ultrasonic vibration signal by the first transducer and propagates in the target fluid. The current echo signal is an electrical signal obtained by the second transducer after receiving and processing the ultrasonic vibration signal reflected by the target fluid when encountering an obstacle (such as a fluid interface, a pipe wall, etc.).

[0048] In step S11, the current echo signal corresponding to the current ultrasonic excitation signal emitted by the ultrasonic flowmeter to the target fluid is obtained, including: The current ultrasonic pulse signal and the current analog voltage signal are generated by the main control module in the ultrasonic flowmeter.

[0049] The current ultrasonic excitation signal is generated by signal synthesis processing of the current ultrasonic pulse signal and the current analog voltage signal based on the ultrasonic emission module in the ultrasonic flowmeter.

[0050] The current ultrasonic excitation signal is sent to the first transducer in the ultrasonic flowmeter by the ultrasonic emission module.

[0051] The current ultrasonic excitation signal is converted into the current ultrasonic vibration signal by the first transducer, so that the second transducer in the ultrasonic flowmeter receives the current ultrasonic vibration signal and converts the current ultrasonic vibration signal into the initial echo signal.

[0052] The initial echo signal converted by the second transducer is collected by the ultrasonic receiving module in the ultrasonic flowmeter, and the initial echo signal is amplified by the ultrasonic receiving circuit in the ultrasonic receiving module to obtain the current echo signal corresponding to the current ultrasonic excitation signal.

[0053] Specifically, in the process of measuring the flow of the target fluid by the ultrasonic flowmeter, the main control module generates a current ultrasonic pulse signal and a current analog voltage signal, and then sends the current ultrasonic pulse signal and the current analog voltage signal to an ultrasonic transmitting module in the ultrasonic flowmeter. The ultrasonic transmitting module can amplify the current ultrasonic pulse signal and the current analog voltage signal by a certain multiple, output a current ultrasonic excitation signal, and send the current ultrasonic excitation signal to a first transducer in the ultrasonic flowmeter. The first transducer converts the current ultrasonic excitation signal into a current ultrasonic vibration signal, and the current ultrasonic vibration signal propagates to a second transducer with the target fluid medium as a propagation carrier, so that the second transducer receives the current ultrasonic vibration signal propagating in the target fluid. The second transducer converts the received current ultrasonic vibration signal into an initial echo signal. The ultrasonic receiving module collects the initial echo signal converted by the second transducer, and outputs a current echo signal corresponding to the current ultrasonic excitation signal after amplification by a certain amplification multiple of the ultrasonic receiving circuit, so as to obtain a current echo signal corresponding to the current ultrasonic excitation signal emitted by the ultrasonic flowmeter to the target fluid.

[0054] In some examples, the ultrasonic transmitting 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: The voltage amplitude of the current analog voltage signal is raised by a boost circuit in the ultrasonic transmitting module to obtain a boosted analog signal corresponding to the current analog voltage signal.

[0055] The amplitude of the current ultrasonic pulse signal is increased by a pulse signal amplification circuit in the ultrasonic transmitting module to obtain an amplified ultrasonic pulse signal corresponding to the current ultrasonic pulse signal.

[0056] 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.

[0057] In this embodiment, the specific process of generating the current ultrasonic excitation signal by the ultrasonic transmitting module based on signal synthesis processing on the current ultrasonic pulse signal and the current analog voltage signal is as follows: the voltage amplitude of the current analog voltage signal generated by the main control module is raised by a boost circuit in the ultrasonic transmitting module to obtain a boosted analog signal corresponding to the current analog voltage signal; at the same time, the amplitude of the current ultrasonic pulse signal is increased by a pulse signal amplification circuit in the ultrasonic transmitting module to obtain an 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.

[0058] It should be understood that since the analog signal voltage after conversion by the digital-to-analog converter is typically low and cannot directly drive subsequent loads such as transducers, it is necessary to increase the voltage amplitude of the current analog voltage signal to be able to drive the subsequent first transducer. This method not only increases the amplitude of the current ultrasonic pulse signal, but also maintains the integrity of the pulse shape of the current ultrasonic pulse signal.

[0059] It should be noted that the echo waveform represents the current echo signal in the time domain, reflecting how the echo signal's amplitude changes over time. The echo waveform contains multiple peaks and troughs. The peak amplitude is the maximum deviation of the waveform. For the current echo signal's echo waveform, the peak amplitude indicates the strength of the current echo signal (i.e., the reflected ultrasonic signal). The average amplitude is the average of the sum of the amplitudes of the multiple peaks in the echo waveform, comprehensively reflecting the overall strength of the current echo signal.

[0060] In step S12, the amplitudes of multiple peaks in the echo waveform of the current echo signal are calculated to obtain the amplitude average of the current echo signal, including: The amplitude of each peak of the plurality of peaks is obtained.

[0061] Determine whether the amplitude of each peak is greater than a preset minimum peak amplitude.

[0062] A peak among the multiple peaks whose amplitude is greater than the preset minimum peak amplitude is used as a target peak.

[0063] The amplitudes corresponding to the multiple target peaks are accumulated to obtain the total amplitude value of the multiple peaks.

[0064] An average value of the total amplitude values ​​of the multiple peaks is calculated to obtain an amplitude average value of the current echo signal.

[0065] like Figure 5 As shown, Figure 5 FIG. 1 is a schematic diagram of a calculation process for the average amplitude value of the current echo signal provided by an embodiment of the present application. Figure 5 In the example, the echo waveform of the current echo signal contains multiple peaks. First, the amplitude of the first peak among the multiple peaks in the echo waveform of the current echo signal is obtained, and it is determined whether the amplitude of the first peak is greater than a preset minimum peak amplitude; the preset minimum peak amplitude is a pre-set minimum amplitude for calculating peak amplitudes. The peak whose amplitude is greater than the preset minimum peak amplitude is determined as the target peak.

[0066] If the amplitude of the first peak is greater than the preset minimum peak amplitude, the first peak can be taken as a target peak, the amplitude of the first peak is recorded, and the amplitude of the first peak is added to the total amplitude value of the current echo signal. If the amplitude of the first peak is less than or equal to the preset minimum peak amplitude, the amplitude of a second peak of the multiple peaks in the echo waveform of the current echo signal is obtained, and it is continued to judge whether the amplitude of the second peak is greater than the preset minimum peak amplitude. If the amplitude of the second peak is greater than the preset minimum peak amplitude, the second peak can be taken as a target peak, the amplitude of the second peak is recorded, and the amplitude of the second peak is added to the total amplitude value 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 a next peak in the current echo signal is obtained, and the amplitude of the next peak is added to the total amplitude value of the current echo signal if the amplitude of the next peak is greater than the preset minimum peak amplitude. The other peaks in the multiple peaks in the echo waveform of the current echo signal are judged in this way.

[0067] Finally, it is judged whether there is still a peak in the echo waveform of the current echo signal that has not been subjected to amplitude judgment. If there is no peak that has not been subjected to amplitude judgment, i.e., the amplitudes of all the peaks have been judged, the average value of the total amplitude value is calculated to obtain the amplitude average value of the current echo signal.

[0068] If there is still a peak that has not been subjected to amplitude judgment, the amplitude of the peak that has not been subjected to amplitude judgment is obtained, and the amplitude of the peak that has not been subjected to amplitude judgment is judged against the preset minimum peak amplitude. If the amplitude of the peak that has not been subjected to amplitude judgment is greater than the preset minimum peak amplitude, the peak that has not been subjected to amplitude judgment is taken as a target peak, and the amplitude of the peak that has not been subjected to amplitude judgment is added to the total amplitude value of the current echo signal. This is continued until all the peaks that have not been subjected to amplitude judgment have been subjected to amplitude judgment, the final total amplitude value is obtained, the average value of the total amplitude value is calculated, and the amplitude average value of the current echo signal is obtained.

[0069] That is, start processing the echo waveform of the current echo signal, obtain the amplitude of the first peak of the current echo signal, and then determine whether the peak amplitude is greater than the preset minimum peak amplitude. If the peak amplitude is less than or equal to the preset minimum peak amplitude, continue to obtain the amplitude of the next peak; if it is greater than the preset minimum peak amplitude, then add the amplitude of the peak to the amplitude sum. Next, determine whether there are still peaks in the current echo signal. If so, continue to obtain the amplitude of the next peak and repeat the above judgment and accumulation process; when there are no peaks in the current echo signal, calculate the average value of the amplitude sum, and end the entire process. The purpose of this process is to gradually process the various peaks in the echo signal, filter out the target peaks that meet the conditions, calculate the total amplitude value and the amplitude average value of the target peaks, and thus extract the echo signal amplitude parameters.

[0070] It should be noted that the first preset condition is to determine whether the amplitude average value of the current echo signal meets the required conditions, that is, the deviation between the amplitude average value and the preset expected amplitude average value is within the preset error range. In this embodiment, the first preset condition can be that the amplitude average value of the current echo signal meets the required conditions. .

[0071] The echo waveform envelope is a curve formed by connecting the peaks of the echo waveform of the current echo signal. It can describe the amplitude variation trend of the current echo signal. The spindle envelope is a specific envelope shape. The spindle envelope is shaped like a spindle, wide in the middle and narrow at the edges. In this embodiment, the spindle envelope can be used as a reference standard for comparison with the echo waveform envelope.

[0072] The cross-correlation value is an indicator that measures the degree of similarity between the overall shape of the echo waveform envelope and the spindle-shaped envelope. The value range is usually between 0 and 1. The closer the cross-correlation value is to 1, the higher the similarity.

[0073] In step S13, after obtaining the amplitude average value of the current echo signal, it is determined whether the amplitude average value of the current echo signal meets the first preset condition, that is, whether the amplitude average value of the current echo signal meets the first preset condition. If it is determined that the amplitude average value of the current echo signal meets the first preset condition, the similarity between the echo waveform envelope of the current echo signal and the spindle-shaped envelope in overall shape is calculated to obtain a cross-correlation value.

[0074] 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 preset threshold, and whether the cross-correlation value meets the requirement can be determined. When the cross-correlation value is greater than the threshold, it can be considered that the echo waveform shape of the echo signal meets the expected requirement. 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.

[0075] If it is determined that the cross-correlation value is greater than the first preset threshold, it can be determined that the echo waveform shape of the current echo signal meets the expected requirement, the current echo signal corresponding to the current ultrasonic excitation signal is determined as the specified echo signal, and then the flow data of the target fluid is calculated according to the specified echo signal. The flow data can be information reflecting the size of the fluid flow, or information reflecting the speed of the fluid flow, etc.

[0076] It can be understood that the embodiment of the present application provides a modulation method of an ultrasonic echo signal, which comprises: obtaining a current echo signal corresponding to a current ultrasonic excitation signal emitted by an ultrasonic flowmeter to a target fluid. The amplitudes of a plurality of wave peaks in the echo waveform of the current echo signal are calculated to obtain an amplitude average value of the current echo signal. Then, in the case where the amplitude average value of the current echo signal meets a first preset condition, the similarity between the echo waveform envelope of the current echo signal and the spindle envelope in the overall shape is calculated to obtain a cross-correlation value. 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. Finally, when it is determined that the cross-correlation value is greater than a first preset threshold, the flow data of the target fluid is calculated according to a specified echo signal determined based on the current ultrasonic excitation signal. The method periodically monitors the amplitude and shape of the echo signal, changes the frequency and amplitude of the ultrasonic excitation signal according to the amplitude and shape of the echo signal, so that the echo signal has better stability during operation, and the measurement accuracy of the ultrasonic flowmeter is improved.

[0077] In a possible implementation, after calculating the amplitudes of a plurality of wave peaks in the echo waveform of the current echo signal to obtain the amplitude average value of the current echo signal, the method comprises: In the case where the amplitude average value of the current echo signal does not meet the first preset condition, the amplification multiple of the ultrasonic receiving circuit in the ultrasonic flowmeter is adjusted or the emission amplitude of the current ultrasonic excitation signal is adjusted according to the emission amplitude of the current ultrasonic excitation signal and the preset maximum amplitude to obtain a next ultrasonic excitation signal.

[0078] As shown in Figure 6 , the flowchart shown in Figure 6 is a flowchart of a modulation method of an ultrasonic echo signal provided by another embodiment of the present application. As shown inFigure 6 In the embodiment of the present invention, after obtaining the amplitude average value of the current echo signal, it is determined whether the amplitude average value of the current echo signal satisfies the first preset condition. If the amplitude average value of the current echo signal does not meet the first preset condition, the amplification factor of the ultrasonic receiving circuit in the ultrasonic flowmeter is adjusted 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, thereby transmitting the next ultrasonic excitation signal into the target fluid through the first transducer to obtain the echo signal corresponding to the next ultrasonic excitation signal, thereby obtaining an echo signal that meets the expected requirements. Among them, 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 transmission amplitude of the ultrasonic excitation signal pre-set by the system, the purpose of which is to prevent the transmission amplitude from being too large and damaging the equipment or causing inaccurate measurement. 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.

[0079] In one possible implementation, when it is determined that the amplitude average value of the current echo signal does not meet the first preset condition, adjusting the amplification factor of the ultrasonic receiving circuit in the ultrasonic flowmeter or adjusting the transmission amplitude of the current ultrasonic excitation signal according to the transmission amplitude of the current ultrasonic excitation signal and the preset maximum amplitude to obtain the next ultrasonic excitation signal includes: Determine whether the current transmission amplitude of the ultrasonic excitation signal is greater than the preset maximum amplitude.

[0080] If the emission amplitude of the current ultrasonic excitation signal is greater than the preset maximum amplitude, the amplification factor of the ultrasonic receiving circuit is adjusted and then the emission amplitude of the current ultrasonic excitation signal is adjusted to obtain the first next ultrasonic excitation signal.

[0081] If the emission amplitude of the current ultrasonic excitation signal is less than or equal to the preset maximum amplitude, the emission amplitude of the current ultrasonic excitation signal is adjusted to obtain a second next ultrasonic excitation signal.

[0082] Specifically, if Figure 6 In the case where it is determined that the amplitude average value of the current echo signal does not meet the first preset condition, , the relationship between the emission amplitude of the current ultrasonic excitation signal and the preset maximum amplitude is determined. If the emission amplitude of the current ultrasonic excitation signal is greater than the preset maximum amplitude, the amplification factor of the ultrasonic receiving circuit is increased, and then the emission amplitude of the current ultrasonic excitation signal is adjusted to the minimum emission amplitude; if the emission amplitude of the current ultrasonic excitation signal is less than or equal to the preset maximum amplitude, the emission amplitude of the current ultrasonic excitation signal is directly increased. When the ultrasonic excitation signal's amplitude exceeds the preset maximum amplitude, the system determines the relationship between the current ultrasonic excitation signal's transmission amplitude and the preset maximum amplitude. If the amplitude exceeds the preset maximum amplitude, the ultrasonic receiving circuit's amplification factor is reduced and the current ultrasonic excitation signal's transmission amplitude is adjusted to the minimum amplitude. If the amplitude is less than or equal to the preset maximum amplitude, the amplitude is directly reduced. The purpose of these two processes is to control the absolute value of (1 - (summed amplitude average / set summed amplitude average)) to be less than 0.1.

[0083] In one possible implementation, when it is determined that the amplitude average value of the current echo signal satisfies the first preset condition, calculating the degree of similarity between the overall shape of the echo waveform envelope of the current echo signal and the spindle-shaped envelope to obtain the cross-correlation value, the method includes: The amplitudes and positions of multiple peaks in the echo waveform of the current echo signal are obtained.

[0084] A fitting curve is drawn according to the amplitudes and positions of the multiple peaks to generate an echo waveform envelope of the current echo signal.

[0085] like Figure 7 As shown, Figure 7 This is a flowchart of a process for generating an echo waveform envelope of an ultrasonic echo signal and a process for determining a cross-correlation value, provided in one embodiment of the present application. Figure 7 In the equation, the peak position is the time point on the time axis of the echo waveform corresponding to the peak, that is, the horizontal coordinate value corresponding to the peak's apex. The peak position reflects the time it takes for the ultrasonic wave to be transmitted, reflected by the reflecting surface, and then received. It 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 approximates the given data points (i.e., the amplitude and position of multiple peaks) as closely as possible to these data points, obtained through mathematical methods such as least squares. The purpose of drawing this fitting curve is to smooth and summarize the discrete data points to more clearly present the overall trend of the data. The resulting fitting curve is the echo waveform envelope of the current echo signal, which reflects the overall profile of the echo signal's amplitude changes over time.

[0086] It should be understood that by generating the echo waveform envelope of the current echo signal by means of a curve fitting method, local fluctuations between peaks can be eliminated, thereby more accurately reflecting the shape characteristics of the echo signal.

[0087] In a possible implementation, in a case where it is determined that the amplitude average value of the current echo signal meets the first preset condition, after the similarity degree in overall shape between the echo waveform envelope line of the current echo signal and the spindle envelope line is calculated to obtain a cross-correlation degree value, the method comprises: If it is determined that the cross-correlation degree value is less than or equal to the first preset threshold value, then according to a frequency adjustment rule, the first transmission frequency value currently adopted by the current ultrasonic excitation signal is adjusted to a second transmission frequency value to obtain a third next ultrasonic excitation signal; wherein the second transmission frequency value is less than the first transmission frequency value.

[0088] As shown in Figure 6 and Figure 7 If it is determined that the cross-correlation degree value is less than or equal to the first preset threshold value, it indicates that the echo waveform envelope line of the current echo signal does not meet the expected shape requirement, and the current echo signal needs to be modulated to obtain an echo signal meeting the expected shape requirement, that is, according to the frequency adjustment rule, the first transmission frequency value currently adopted by the current ultrasonic excitation signal is adjusted to the second transmission frequency value, so as to obtain the third next ultrasonic excitation signal (i.e. the newly generated ultrasonic excitation signal after adjustment). Wherein 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, that is, the transmission frequency value of the third next ultrasonic excitation signal.

[0089] Wherein the frequency adjustment rule is a rule for guiding how to adjust the transmission frequency of the ultrasonic excitation signal. In the embodiment, the frequency adjustment rule can be to finely adjust the transmission frequency value of the test ultrasonic excitation signal corresponding to the test echo signal with the amplitude average value of the echo waveform being the second, after the current ultrasonic excitation signal is finely adjusted according to the frequency adjustment rule, the finely adjusted ultrasonic excitation signal is re-emitted to start the cycle process described in Figure 6 until all processes are met, that is, when the cross-correlation degree value of the echo waveform envelope line of the finely adjusted ultrasonic excitation signal and the spindle envelope line is greater than the first preset threshold value, the echo signal modulation process ends, at this time the transmission frequency of the finely adjusted ultrasonic excitation signal is the second transmission frequency. Wherein the first transmission frequency value is the transmission frequency value of the test ultrasonic excitation signal corresponding to the test echo signal with the amplitude average value of the echo waveform being the first. That is, the transmission frequency value of the test ultrasonic excitation signal corresponding to the test echo signal with the amplitude average value of the echo waveform being the first, and the transmission frequency value of the test ultrasonic excitation signal corresponding to the test echo signal with the amplitude average value of the echo waveform being the second are the two groups of optimal transmission frequency values corresponding to the optimal echo signal amplitude.

[0090] It should be understood that Figure 6The echo signal modulation process aims to make the amplitude and waveform characteristics of the echo signal as close as possible to the preset target by continuously adjusting the amplitude of the transmitted signal and the amplification of the ultrasonic receiving circuit, so as to achieve the effect of echo signal modulation.

[0091] As shown in Figure 8 , Figure 8 is a flowchart of a process for determining the optimal transmission frequency value corresponding to the optimal amplitude of the echo signal according to an embodiment of the present application. Figure 8 In the process, after the system of the ultrasonic flowmeter is powered on, the initial transmission amplitude of the test ultrasonic excitation signal of the ultrasonic flowmeter and seven different transmission frequencies are set. Then, the first group of test ultrasonic excitation signals is transmitted and the echo waveform of the corresponding test echo signal is processed to obtain the amplitude average value of the test echo signal. Then, the second group of test ultrasonic excitation signals is transmitted and the echo waveform of the corresponding test echo signal is processed, and so on until the seven groups of transmission frequency scanning are completed. If the seven groups of frequency scanning are completed, the transmission frequency value of the test ultrasonic excitation signal corresponding to the test echo signal with the first amplitude average value of the echo waveform and the transmission frequency value of the test ultrasonic excitation signal corresponding to the test echo signal with the second amplitude average value of the echo waveform are recorded, and the process ends. Through the scanning of different transmission frequencies, the two optimal transmission frequency values that make the amplitude of the test echo signal optimal are determined. The first optimal transmission frequency value is the transmission frequency value of the test ultrasonic excitation signal corresponding to the test echo signal with the first amplitude average value of the echo waveform, and the second optimal transmission frequency value is the transmission frequency value of the test ultrasonic excitation signal corresponding to the test echo signal with the second amplitude average value of the echo waveform. It should be noted that in this embodiment, seven different transmission frequencies are set, and other numbers of different transmission frequencies can also be set according to application requirements.

[0092] In some examples, Figures 9-11 is a schematic diagram of experimental results of the influence of related parameters on ultrasonic echo signals. Figure 9 is a schematic diagram of experimental results of the influence of the transmission amplitude of the ultrasonic excitation signal on the ultrasonic echo signal according to an embodiment of the present application. In the diagram, Figure 9 (9-a) in the diagram is an ultrasonic echo signal when the transmission frequency of the ultrasonic excitation signal is 2.33 MHz and the transmission amplitude is 6.0 V, Figure 9 (9-b) in the diagram is an ultrasonic echo signal when the transmission frequency of the ultrasonic excitation signal is 2.33 MHz and the transmission amplitude is 8.0 V, Figure 9 (9-c) in the diagram is an ultrasonic echo signal when the transmission frequency of the ultrasonic excitation signal is 2.33 MHz and the transmission amplitude is 12.0 V, Figure 9(9-d) in the figure is the ultrasonic echo signal when the transmission frequency of the ultrasonic excitation signal is 2.33MHz and the transmission amplitude is 16.0V. Figure 9 In the experiment, when the transmitting frequency of the ultrasonic excitation signal is 2.33MHz, the transmitting frequency is the best frequency. The size of the transmitting amplitude will directly affect the receiving amplitude, but the overall envelope of the echo waveform of the echo signal is still spindle-shaped. Through experiments, when the transmitting frequency is the best and the transmitting amplitude is also the best (such as Figure 9 As shown in (9-b), the waveform of the middle main part of the echo signal is complete and the waveform frequency of the echo signal is close to the transmission frequency, which has obvious prominent features. It is beneficial to 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 middle part of the echo signal is close to the amplitude of the two sides, and only a small part of the waveform frequency is close to the transmission frequency, indicating that the remaining waveform is strongly attenuated by other factors, which will cause greater interference to the subsequent time difference algorithm. When the transmission amplitude is large (such as Figure 9 As shown in (9-d), the middle part begins to be distorted, 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 of experimental results on the effect of the transmission frequency of the ultrasonic excitation signal on the ultrasonic echo signal provided by an embodiment of the present application. Figure 10 (10-a) is the ultrasonic echo signal when the ultrasonic excitation signal has an emission amplitude of 8.0V and an emission frequency of 2.74MHz. Figure 10 (10-b) is the ultrasonic echo signal when the ultrasonic excitation signal has an emission amplitude of 8.0V and an emission frequency of 2.53MHz. Figure 10 (10-c) in the figure is the ultrasonic echo signal when the ultrasonic excitation signal has an emission amplitude of 8.0V and an emission frequency of 2.33MHz. Figure 10 (10-d) in the figure is the ultrasonic echo signal when the ultrasonic excitation signal has an emission amplitude of 8.0V and an emission frequency of 2.17MHz. Figure 10 (10-e) in the equation is the ultrasonic echo signal when the ultrasonic excitation signal has an emission amplitude of 8.0V and an emission frequency of 2.04MHz. Figure 10 (10-f) is the ultrasonic echo signal when the ultrasonic excitation signal has an emission amplitude of 8.0V and an emission frequency of 1.91MHz. Figure 10 In the experiment, when the emission amplitude of the ultrasonic excitation signal is the optimal amplitude (i.e., the emission amplitude is 8.0V), the attenuation degree of the ultrasonic echo signal is more obvious at different emission 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, and the continuity of some waveforms is lost, making it impossible to perform the subsequent time difference algorithm for extracting the echo signal. Figure 11is a schematic diagram of experimental results about the influence of pipe diameter on ultrasonic echo signals according to an embodiment of the present application. In the diagram, Figure 11 (11-a) in the diagram is an ultrasonic echo signal generated by an ultrasonic excitation signal in a UPVC pipe, DN25 pipe diameter, Figure 11 (11-b) in the diagram is an ultrasonic echo signal generated by an ultrasonic excitation signal in a UPVC pipe, DN32 pipe diameter, Figure 11 (11-c) in the diagram is an ultrasonic echo signal generated by an ultrasonic excitation signal in a PVC pipe, DN25 pipe diameter. In the diagram, Figure 11 In the diagram, two different pipe diameters (nominal diameter DN32 and nominal diameter DN25) and different pipe materials (hard polyvinyl chloride UPVC and polyvinyl chloride PVC) are tested, and the received echo signals are not much different. Different pipe materials have different ultrasonic absorption and reflection, and there are different echo signal tails, but the main part of the trend is basically consistent.

[0093] It can be understood that the ultrasonic flowmeter provided by the embodiment of the present application can modulate the echo signal. Compared with the existing ultrasonic flowmeter, the ultrasonic flowmeter has the following advantages: (1) The existing ultrasonic flowmeter measures a single medium, and one sensor can only measure a few fixed liquid media. The ultrasonic flowmeter provided by the embodiment of the present application can change the transmission frequency and amplitude of the ultrasonic wave, enhance the sound transmission, and be compatible with more fluid media.

[0094] (2) The existing ultrasonic flowmeter has high requirements for the flow state of the measured liquid, and a small amount of bubbles and small particles of solid will greatly affect the result. The ultrasonic flowmeter provided by the embodiment of the present application can change the transmission frequency and amplitude of the ultrasonic wave, enhance the sound transmission, and greatly reduce the interference with the result.

[0095] (3) The existing ultrasonic flowmeter has strict requirements for the pipe wall material to be measured, and cannot measure the pipe material with weak sound transmission. The ultrasonic flowmeter provided by the embodiment of the present application changes the transmission amplitude and the amplification multiple of the receiving circuit to enhance the strength of the echo signal and be compatible with more pipe materials.

[0096] (4) The existing ultrasonic flowmeter does not have much requirement for the quality of the echo signal, or the waveform is spindle-shaped in the experimental environment. However, through experiments, it is found that when the running time increases, the state of the fluid changes, which affects the echo, and finally greatly affects the result. The ultrasonic flowmeter provided by the embodiment of the present application periodically detects the echo signal and continuously modifies the parameters of the transmission waveform.

[0097] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean 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.

[0098] Corresponding to a modulation method of an ultrasonic echo signal in the above embodiment, Figure 12 A schematic structural diagram of a modulation device for an ultrasonic echo signal provided in one embodiment of the present application is shown. For ease of explanation, only the portion related to the embodiment of the present application is shown.

[0099] Reference Figure 12 , the ultrasonic echo signal modulation device 6 of this embodiment includes: The signal acquisition module 61 is used to acquire a current echo signal corresponding to a current ultrasonic excitation signal emitted by the ultrasonic flowmeter to the target fluid.

[0100] The amplitude calculation module 62 is used to calculate the amplitudes of multiple peaks in the echo waveform of the current echo signal to obtain the average amplitude of the current echo signal.

[0101] The first determination module 63 is configured to calculate the degree of similarity between the overall shape of the echo waveform envelope of the current echo signal and the spindle-shaped envelope, and obtain a cross-correlation value, if it is determined that the average amplitude value of the current echo signal satisfies a first preset condition. The first preset condition is configured to indicate that the deviation between the average amplitude value and a preset expected average amplitude value is within a preset error range.

[0102] The second determining module 64 is configured to calculate the flow rate data of the target fluid according to the designated echo signal determined based on the current ultrasonic excitation signal when it is determined that the cross-correlation value is greater than the first preset threshold.

[0103] It should be noted that the information interaction, execution process, etc. between the modules in the above-mentioned ultrasonic echo signal modulation device 6 are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0104] The present 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 one embodiment of the present application. Figure 13 The terminal device 7 of 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, the steps of any one of the above-mentioned methods for modulating ultrasonic echo signals are implemented.

[0105] The embodiment of the present application further provides a computer readable storage medium, which stores a computer program. The computer program is executed by a processor to realize the steps in the above-mentioned various method embodiments.

[0106] The embodiment of the present application provides a computer program product. When the computer program product is run on a mobile terminal, the mobile terminal is caused to execute the steps in the above-mentioned various method embodiments.

[0107] The integrated unit, if realized in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the present application realizes all or part of the processes in the above-mentioned embodiment methods, which can be completed by instructing related hardware through a computer program. The computer program can be stored in a computer readable storage medium. The computer program, when executed by a processor, can realize the steps in the above-mentioned various method embodiments. The computer program includes computer program code, which can be in the form of source code, object code, executable files or some intermediate forms. The computer readable medium at least includes any entity or device capable of carrying the computer program code to the photographing device / terminal equipment, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium. For example, U disk, mobile hard disk, magnetic disk or optical disk, etc. In some jurisdictions, according to legislation and patent practice, the computer readable medium cannot be an electrical carrier signal and a telecommunication signal.

[0108] In the above-mentioned embodiments, the description of each embodiment has its own focus. The parts not described or recorded in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0109] Those skilled in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0110] In the embodiments provided by the present application, it should be understood that the disclosed apparatus / network device and method can be implemented in other manners. For example, the embodiments of the apparatus / network device described above are merely illustrative. For example, the division of the modules or units is merely logical function division, and there can be another division manner in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, devices or units, and can be electrical, mechanical or in other forms.

[0111] The units described as separated components can or can not be physically separated, and the components displayed as units can or can not be physical units, i.e., can be located in one place or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purposes of the embodiments of the present application.

[0112] The above embodiments are merely used to describe the technical solutions of the present application, but not to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalent replacements; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for modulating an ultrasonic echo signal, characterized in that: include: Obtaining a current echo signal corresponding to a current ultrasonic excitation signal emitted by the ultrasonic flowmeter to the target fluid; Calculating the amplitudes of multiple peaks in the echo waveform of the current echo signal to obtain an amplitude average of the current echo signal; When it is determined that the amplitude average value of the current echo signal satisfies a first preset condition, calculating the degree of similarity between the overall shape of the echo waveform envelope of the current echo signal and the spindle-shaped envelope to obtain a cross-correlation value; wherein the first preset condition is used to indicate that a deviation between the amplitude average value and a preset expected amplitude average value is within a preset error range; When it is determined that the cross-correlation value is greater than a first preset threshold, the flow data of the target fluid is calculated according to a designated echo signal determined based on the current ultrasonic excitation signal.

2. The method for modulating an ultrasonic echo signal according to claim 1, wherein: After calculating the amplitudes of multiple peaks in the echo waveform of the current echo signal to obtain the amplitude average of the current echo signal, the method includes: When it is determined that the amplitude average value of the current echo signal does not meet the first preset condition, the amplification factor of the ultrasonic receiving circuit in the ultrasonic flowmeter is adjusted or the emission amplitude of the current ultrasonic excitation signal is adjusted according to the emission amplitude of the current ultrasonic excitation signal and the preset maximum amplitude to obtain the next ultrasonic excitation signal.

3. The method for modulating an ultrasonic echo signal according to claim 2, wherein: When it is determined that the amplitude average value of the current echo signal does not satisfy the first preset condition, adjusting the amplification factor 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 the next ultrasonic excitation signal, including: Determining 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, adjusting the amplification factor of the ultrasonic receiving circuit and then adjusting the emission amplitude of the current ultrasonic excitation signal 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, the emission amplitude of the current ultrasonic excitation signal is adjusted to obtain a second next ultrasonic excitation signal.

4. The method for modulating an ultrasonic echo signal according to claim 2, wherein: When it is determined that the amplitude average value of the current echo signal satisfies the first preset condition, the method comprises: calculating the degree of similarity between the overall shape of the echo waveform envelope of the current echo signal and the spindle-shaped envelope to obtain a cross-correlation value. If it is determined that the cross-correlation value is less than or equal to the first preset threshold, the first transmission frequency value currently used by the current ultrasonic excitation signal is adjusted to the second transmission frequency value according to the frequency adjustment rule to obtain the third next ultrasonic excitation signal; wherein, the second transmission frequency value is less than the first transmission frequency value.

5. The method for modulating an ultrasonic echo signal according to claim 1, wherein: The calculating the amplitudes of multiple peaks in the echo waveform of the current echo signal to obtain the amplitude average value of the current echo signal includes: Obtaining the amplitude of each peak of the plurality of peaks; Determining whether the amplitude of each peak is greater than a preset minimum peak amplitude; The peak with an amplitude greater than the preset minimum peak amplitude among the multiple peaks is used as the target peak; Accumulating the amplitudes corresponding to the plurality of target peaks to obtain a total amplitude value of the plurality of peaks; An average value of the total amplitude values ​​of the multiple peaks is calculated to obtain an amplitude average value of the current echo signal.

6. The method for modulating an ultrasonic echo signal according to claim 1, wherein: When determining that the amplitude average value of the current echo signal satisfies the first preset condition, the method includes calculating the degree of similarity between the overall shape of the echo waveform envelope of the current echo signal and the spindle-shaped envelope to obtain the cross-correlation value. Acquire the amplitudes and positions of multiple peaks in the echo waveform of the current echo signal; A fitting curve is drawn according to the amplitudes of the multiple peaks and the positions of the multiple peaks to generate the echo waveform envelope of the current echo signal.

7. The method for modulating an ultrasonic echo signal according to any one of claims 1 to 6, wherein: The obtaining of a current echo signal corresponding to a current ultrasonic excitation signal emitted by the ultrasonic flowmeter to the target fluid includes: Generate 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 the ultrasonic transmitting module in the ultrasonic flowmeter to generate the current ultrasonic excitation signal; Sending the current ultrasonic excitation signal to the 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 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; The initial echo signal converted by the second transducer is collected by the ultrasonic receiving module in the ultrasonic flowmeter, and the initial echo signal is amplified by the ultrasonic receiving circuit in the ultrasonic receiving module to obtain the current echo signal corresponding to the current ultrasonic excitation signal.

8. The method for modulating an ultrasonic echo signal according to claim 7, wherein: The ultrasonic transmitting 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: The voltage amplitude of the current analog voltage signal is increased by the boost circuit in the ultrasonic transmitting module to obtain a boosted analog signal corresponding to the current analog voltage signal; The amplitude of the current ultrasonic pulse signal is increased by the pulse signal amplification circuit in the ultrasonic transmitting module to obtain an amplified ultrasonic pulse signal corresponding to the current ultrasonic pulse signal; The pulse signal amplification circuit synthesizes the boosted analog signal and the amplified ultrasonic pulse signal to obtain the current ultrasonic excitation signal.

9. An ultrasonic flow meter, characterized in that: include: 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 to the ultrasonic transmitting module and the ultrasonic receiving module respectively, and is used 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 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; The first transducer is configured to convert the ultrasonic excitation signal into an ultrasonic vibration signal, and transmit the ultrasonic vibration signal to a target fluid, so that the ultrasonic vibration signal is propagated 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; The ultrasonic receiving module is connected to the second transducer, and is used to collect the initial echo signal converted by the second transducer, amplify the initial echo signal through the ultrasonic receiving circuit, output an echo signal, and send the echo signal to the main control module; The main control module is further configured to execute the ultrasonic echo signal modulation method as described in any one of claims 1 to 8 above.

10. A computer program product, characterized in that The invention comprises a computer program which, when executed, causes the method according to any one of claims 1 to 8 to be performed.

Images