Ultrasonic flow meter and ultrasonic echo secondary oscillation identification method thereof

Abstract

The present application relates to a method for identifying secondary oscillation of ultrasonic echoes for ultrasonic flowmeters. In the above method, the ultrasonic echoes of the ultrasonic flowmeter are obtained, and the target peaks, that is, those peaks whose amplitudes are greater than the first wave threshold, are determined based on the ultrasonic echoes. According to the order in which the target peaks appear, the maximum peak value in the first peak segment is retrieved and determined as the first target amplitude, and the maximum peak value in the second peak segment is retrieved and determined as the second target amplitude. The first peak segment refers to a peak segment in which a plurality of consecutive peak values ​​first increase and then decrease, and the second peak segment is a peak segment located after the first peak segment. Based on the first target amplitude and the second target amplitude, it is determined whether there is a secondary oscillation phenomenon in the ultrasonic echo. This method can effectively avoid metering errors caused by misjudgment of peak amplitudes by improving the accuracy of identifying ultrasonic secondary oscillations.

Description

Technical Field

[0001] The present application relates to the technical field of ultrasonic flow measurement, and in particular to a method for identifying secondary oscillation of ultrasonic echoes of an ultrasonic flow meter. Background Art

[0002] Ultrasonic flowmeter is a kind of flow measurement equipment widely used in industrial and commercial fields. It uses the propagation characteristics of ultrasonic signals in fluids to calculate flow. Its working principle is to transmit ultrasonic signals and measure the time difference of signal propagation in the fluid, so as to calculate the flow rate and flow of the fluid. Ultrasonic flowmeter has the advantages of non-contact, non-destructive, high accuracy and wide application range, and is suitable for measuring gas and liquid flow.

[0003] However, in practical applications, the measurement accuracy of ultrasonic flowmeters may be affected by many factors. Among them, the secondary oscillation phenomenon is an important issue. This phenomenon may cause wrong waves and affect the accuracy of measurement. Summary of the invention

[0004] Based on this, it is necessary to provide an ultrasonic echo secondary oscillation identification method for an ultrasonic flow meter in response to the above technical problems. This method can improve the accuracy of identifying ultrasonic secondary oscillation and effectively reduce measurement errors.

[0005] In a first aspect, the present application provides a method for identifying secondary oscillation of ultrasonic echoes of an ultrasonic flowmeter. The method comprises:

[0006] Acquire ultrasonic echo of ultrasonic flow meter;

[0007] Based on the ultrasonic echo, a target wave peak is determined; wherein the target wave peak is a wave peak of a wave greater than a first wave threshold in the ultrasonic echo;

[0008] According to the order in which the target peaks appear, the peak values ​​of the target peaks are retrieved. If there are multiple first peak segments in which the peak values ​​first increase and then decrease in the target peaks, the maximum value of the peaks in the first peak segment is recorded as the first target amplitude;

[0009] According to the order in which the target peaks appear, the peak value of the second peak segment in the target peak is retrieved. If there are multiple consecutive peak values ​​in the second peak segment that increase first and then decrease, the maximum value of the peak in the second peak segment is recorded as the second target amplitude; wherein the second peak segment is the peak segment composed of the peaks located after the first peak segment in the target peak;

[0010] Whether there is secondary oscillation in the ultrasonic echo is identified according to the first target amplitude and the second target amplitude.

[0011] In one embodiment, traversing the ultrasonic echoes to determine the target peak includes:

[0012] Filter out the data points in the ultrasonic echo that are greater than the first wave threshold;

[0013] Determine whether there are consecutive data points that first increase and then decrease. If so, record the maximum value among the consecutive data points as a wave peak;

[0014] Traverse the data points in the ultrasonic echo to determine the target peak.

[0015] In one embodiment, determining the second peak segment includes:

[0016] According to the order in which the target peaks appear, determine the last peak in the first peak segment and use it as the reference peak;

[0017] The position of the reference peak is obtained, and a peak segment consisting of all peaks after the position of the reference peak in the target peak is taken as the second peak segment.

[0018] In one embodiment, identifying whether there is secondary oscillation in the ultrasonic echo according to the first target amplitude and the second target amplitude includes:

[0019] If the height difference between the first target amplitude and the first wave threshold is smaller than the height difference between the second target amplitude and the first wave threshold, then secondary oscillation exists in the ultrasonic echo;

[0020] or,

[0021] If the second target amplitude is greater than the first target amplitude, secondary oscillation exists in the ultrasonic echo.

[0022] In one embodiment, the method further comprises:

[0023] If the presence of secondary oscillation in the ultrasonic echo is identified, the nominal resonant frequency of the transducer in the ultrasonic flow meter is obtained;

[0024] Determine the excitation frequency adjustment range of the transducer according to the nominal resonant frequency; wherein the nominal resonant frequency is the center of the excitation frequency adjustment range;

[0025] The excitation frequency of the transducer is adjusted based on the excitation frequency adjustment interval.

[0026] In one embodiment, adjusting the excitation frequency of the transducer based on the excitation frequency adjustment range includes:

[0027] Taking the nominal resonant frequency as the starting point within the excitation frequency adjustment range, the excitation frequency is adjusted upward with the first step length and adjusted downward with the second step length in an alternating order to obtain a first frequency and a second frequency; wherein the frequency obtained by adjusting the excitation frequency upward is recorded as the first frequency, and the frequency obtained by adjusting the excitation frequency downward is recorded as the second frequency;

[0028] A target excitation frequency is determined based on at least one of the first frequency and the second frequency, and the target excitation frequency is used as the excitation frequency after the transducer is adjusted.

[0029] In one embodiment, determining the target excitation frequency based on at least one of the first frequency and the second frequency includes:

[0030] Each time the excitation frequency is adjusted once, a first frequency or a second frequency is obtained, the transducer is driven with the first frequency or the second frequency, and when the first frequency or the second frequency is used as the excitation frequency, it is identified whether there is secondary oscillation in the ultrasonic echo of the ultrasonic flowmeter, and a secondary oscillation identification result corresponding to the first frequency or a secondary oscillation identification result corresponding to the second frequency is obtained;

[0031] Based on the secondary oscillation identification result, one of the first frequency or the second frequency is determined as the target excitation frequency; wherein, within the excitation frequency adjustment range, taking the nominal resonant frequency as the starting point, the excitation frequency is adjusted upward with the first step size and downward with the second step size in an alternating order, and the upward and downward adjustments are continuously cycled until the target excitation frequency is determined based on the secondary oscillation identification result.

[0032] In one embodiment, the method further includes: identifying whether there is secondary oscillation in the ultrasonic echo of the ultrasonic flow meter if at least one of the following is satisfied:

[0033] The change value of the working temperature of the ultrasonic flowmeter is greater than the temperature threshold;

[0034] The change in the sound velocity in the ultrasonic flow meter is greater than the sound velocity threshold;

[0035] The ultrasonic flow meter is powered on again;

[0036] The timing time of arrival at the ultrasonic flow meter.

[0037] In one embodiment, determining a change in the speed of sound in an ultrasonic flow meter includes:

[0038] Obtain the flight time and flight distance of the first wave of the target in the ultrasonic echo;

[0039] Determine the target sound speed based on the flight time and distance;

[0040] The difference between the target sound velocity and the reference sound velocity is taken as the change value of the sound velocity in the ultrasonic flow meter.

[0041] In one embodiment, obtaining an ultrasonic echo of an ultrasonic flow meter includes:

[0042] Acquire the ultrasonic echo of the ultrasonic flow meter by sampling;

[0043] Extracting the amplitude of the ultrasonic echo and determining whether the amplitude of the ultrasonic echo is within a valid range;

[0044] If not, the ultrasonic echo is gain-adjusted based on the amplifier circuit to control the amplitude of the ultrasonic echo.

[0045] In a second aspect, the present application further provides an ultrasonic flow meter, including a memory and a processor, wherein the memory stores a computer program, and the processor can execute the computer program to implement the ultrasonic echo secondary oscillation identification method for the ultrasonic flow meter according to the first aspect.

[0046] The above-mentioned ultrasonic echo secondary onset identification method for ultrasonic flowmeter obtains the ultrasonic echo of the ultrasonic flowmeter and determines the target peaks based on the ultrasonic echo, that is, those peaks whose amplitudes are greater than the first wave threshold. According to the order in which the target peaks appear, the maximum peak value in the first peak segment is retrieved and determined as the first target amplitude, and the maximum peak value in the second peak segment is retrieved and determined as the second target amplitude. The first peak segment refers to a peak segment in which multiple consecutive peak values ​​first increase and then decrease, and the second peak segment is the peak segment located after the first peak segment. Based on the first target amplitude and the second target amplitude, it is determined whether there is a secondary onset phenomenon in the ultrasonic echo. This method can effectively avoid metering errors caused by misjudgment of peak amplitudes by improving the accuracy of identifying ultrasonic secondary onsets. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a flow chart of a method for identifying secondary oscillation of an ultrasonic echo of an ultrasonic flowmeter in one embodiment;

[0048] Figure 2 A waveform diagram of a first wave peak segment and a second wave peak segment in one embodiment;

[0049] Figure 3 A flowchart for determining a target peak in one embodiment;

[0050] Figure 4 A flowchart for determining a second peak segment in one embodiment;

[0051] Figure 5 A flowchart for determining an adjustment interval of an excitation frequency in one embodiment;

[0052] Figure 6 A flowchart of adjusting the excitation frequency of a transducer based on an excitation frequency adjustment range in one embodiment;

[0053] Figure 7 A flowchart of determining a target excitation frequency based on at least one of a first frequency and a second frequency in one embodiment;

[0054] Figure 8 A flow chart of determining a change in the speed of sound in an ultrasonic flow meter in one embodiment;

[0055] Fig. 9 FIG. 1 is a diagram showing the internal structure of an ultrasonic flow meter in one embodiment. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Unless otherwise defined, the technical terms or scientific terms involved in the present application should have the general meaning understood by people with general skills in the technical field to which the present application belongs. The words such as "one", "a", "a kind of", "the", "these" and the like in the present application do not represent quantitative restrictions, and they can be singular or plural. The terms "first", "second", "third", etc. involved in the present application are only used to distinguish similar objects and do not represent a specific ordering for objects.

[0057] In one embodiment, Figure 1 As shown, a method for identifying the secondary oscillation of ultrasonic echoes for ultrasonic flowmeters is provided, wherein the ultrasonic flowmeter is a device that uses ultrasonic echo detection technology to measure the flow of fluids, and transmits and receives ultrasonic signals, calculates the flight time of the signals to determine the fluid velocity, and thus obtains the flow. The method specifically includes the following steps:

[0058] Step 101: Acquire an ultrasonic echo of an ultrasonic flow meter;

[0059] Specifically, during the measurement process of an ultrasonic flowmeter, an ultrasonic signal needs to be emitted to pass through the measured fluid. When the ultrasonic signal encounters an obstacle in the fluid or a pipe wall, it will be reflected to form an echo. The receiver of the flowmeter captures these reflected ultrasonic echo signals. For example, during the measurement process of an ultrasonic flowmeter, the transducer can emit an ultrasonic signal to pass through the measured fluid. When the ultrasonic signal encounters an obstacle in the fluid or a pipe wall, it will be reflected to form an echo. The transducer in the flowmeter can also capture these reflected ultrasonic echo signals. Among them, in an ultrasonic flowmeter, the transducer (also called an ultrasonic probe or sensor) is responsible for completing the two functions of transmitting and receiving ultrasonic signals.

[0060] Furthermore, the received ultrasonic echo signal may be an analog signal, which may be converted into a digital signal by an ADC converter or a TDC converter for subsequent processing and analysis. The echo signal converted into a digital signal may be recorded as data, and the echo signal data may include parameters such as amplitude.

[0061] Step 102: determining a target wave peak based on the ultrasonic echo; wherein the target wave peak is a wave peak of a wave greater than a first wave threshold in the ultrasonic echo;

[0062] Specifically, the first wave threshold refers to a preset level value used to distinguish valid signals from noise in an ultrasonic echo signal. The first wave threshold is usually determined based on experience and experimental data. A target peak refers to a peak in an ultrasonic echo whose amplitude is greater than the first wave threshold. Not all peaks are considered target peaks. Only those peaks whose amplitude exceeds the first wave threshold are selected as target peaks, and there is at least one target peak.

[0063] Step 103: searching for the peak values ​​of the target peaks in the order in which the target peaks appear. If there are multiple first peak segments in which the peak values ​​first increase and then decrease in the target peaks, the maximum value of the peaks in the first peak segment is recorded as the first target amplitude.

[0064] Specifically, the peak values ​​of the target peaks are retrieved according to the order in which the target peaks appear. Retrieval refers to checking the amplitude of each target peak and comparing the amplitude of each target peak. The first peak segment refers to a peak segment composed of a plurality of consecutive target peaks whose peak values ​​increase first and then decrease among the target peaks in the order in which they appear. The maximum value of the amplitude of the target peak in the first peak segment is recorded as the first target amplitude.

[0065] Step 104: searching for the peak value of the second peak segment in the target peak according to the order in which the target peaks appear; if there are multiple consecutive peak values ​​in the second peak segment that first increase and then decrease, the maximum value of the peak in the second peak segment is recorded as the second target amplitude; wherein the second peak segment is a peak segment composed of the peaks in the target peak that are located after the first peak segment;

[0066] Specifically, the second peak segment refers to a peak segment that is located after the first peak segment and is composed of a plurality of consecutive target peaks whose peak values ​​first increase and then decrease. According to the order of the target peaks, the peak value of each target peak in the second peak segment is retrieved. Among them, the retrieval refers to checking the amplitude of each target peak in the second peak segment and comparing the amplitude of each target peak. The maximum amplitude of the target peak in the second peak segment is recorded as the second target amplitude.

[0067] It should be noted that if Figure 2 As shown in the figure, it is a waveform diagram of the first wave peak segment and the second wave segment, where the horizontal axis represents time and the vertical axis represents the level amplitude. It can be seen from the figure that the red frame is a wave greater than the first wave threshold, and the two black frames are the first wave peak segment and the second wave peak segment, and both wave peak segments are composed of target wave peaks that increase first and then decrease, and the second wave peak segment is located after the first wave.

[0068] Step 105: Identify whether there is secondary oscillation in the ultrasonic echo according to the first target amplitude and the second target amplitude.

[0069] Specifically, secondary onset refers to the situation where the echo reaches the amplitude for the first time, starts to decay, and then starts to onset again, and the height after the second onset exceeds the amplitude of the first onset. Compare the first target amplitude and the second target amplitude. If the second target amplitude is greater than the first target amplitude, it means that secondary onset exists; if the second target amplitude is less than the first target amplitude, it means that secondary onset does not exist. Exemplarily, the height difference between the first target amplitude and the first wave threshold and the height difference between the second target amplitude and the first wave threshold can also be compared. If the height difference between the first target amplitude and the first wave threshold is less than the height difference between the second target amplitude and the first wave threshold, it means that secondary onset exists.

[0070] In the above-mentioned ultrasonic echo secondary oscillation identification method for ultrasonic flowmeter, the ultrasonic echo of the ultrasonic flowmeter is obtained, and the target peaks, that is, those peaks with amplitudes greater than the first wave threshold, are determined based on the ultrasonic echo. According to the order in which the target peaks appear, the maximum peak value in the first peak segment is retrieved and determined as the first target amplitude, and the maximum peak value in the second peak segment is retrieved and determined as the second target amplitude. The first peak segment refers to a peak segment in which a plurality of consecutive peak values ​​first increase and then decrease, and the second peak segment is a peak segment located after the first peak segment. By comparing the first target amplitude and the second target amplitude or the height difference between the first and second target amplitudes and the first wave threshold, it is determined whether there is a secondary oscillation phenomenon in the ultrasonic echo. This method can effectively avoid the metering error caused by misjudgment of the peak amplitude by improving the accuracy of identifying ultrasonic secondary oscillation, and reduces the recognition power consumption and recognition cost.

[0071] Exemplarily, to obtain the ultrasonic echo in the ultrasonic flowmeter and determine whether there is a secondary oscillation, multiple measurements can be performed by continuously raising the first wave threshold, and the flight time will be calculated in each measurement. It should be noted that the flight time corresponding to a wave is fixed. Only when the first wave threshold is raised to reach the next wave, the flight time will change. The difference in flight time corresponding to adjacent waves is fixed, which is approximately the excitation period (at a frequency of 500K, the difference in flight time corresponding to adjacent waves is approximately 2us). When the first wave threshold is raised to the wave where the amplitude is located, the flight time reaches the maximum. If there is no secondary oscillation, the flight time of the wave where the amplitude is located is the largest. If the first wave threshold is raised again, new waves will not be found, and new and larger flight times will not be collected. If there is secondary oscillation, after the highest peak of the first wave segment, the threshold of the first wave is continuously raised, and a new wave can be collected. The corresponding flight time is not a fixed difference of 2us (500K for example) from the flight time collected at the highest peak of the first wave segment, but because there are multiple waves, the flight time difference is the number of waves * 2us. For example, if there is a difference of 3 waves, the flight time will differ by 6us. In this way, it can be determined whether there is secondary oscillation.

[0072] In one embodiment, Figure 3 As shown, traversing the ultrasonic echo and determining the target peak includes the following steps:

[0073] Step 301: Filter out data points in the ultrasonic echo that are greater than the first wave threshold;

[0074] Specifically, the first wave threshold refers to the preset level value used to distinguish valid signals from noise in the ultrasonic echo signal. The first wave threshold is usually determined based on experience and experimental data. Before data point screening, the ultrasonic echo signal is usually converted into a digital signal by ADC or TDC. It is necessary to traverse these digitized echo signal data points, that is, check the amplitude of each data point one by one. The data point can refer to Figure 2 In the , the points with the ordinate level amplitude corresponding to each abscissa time greater than the first wave threshold. The amplitude of each data point is compared with the preset first wave threshold. If the amplitude of the data point is greater than the first wave threshold, then this data point is considered to be screened out.

[0075] Step 302: determine whether there are consecutive data points that first increase and then decrease, and if so, record the maximum value among the consecutive data points as a wave crest;

[0076] Specifically, in an ultrasonic echo signal, a peak refers to the highest point of the signal amplitude, which represents the strongest signal reflected by an obstacle encountered by the ultrasonic signal during propagation. After selecting the data points greater than the first wave threshold in step 501, it is necessary to check the continuous changes of these data points to determine the location of the peak. To determine a peak, it is necessary to find a set of continuous data points that first show an increasing trend and then a decreasing trend. This change trend indicates the process of the signal growing to reaching a peak and then attenuating.

[0077] Step 303: Traverse the data points in the ultrasonic echo to determine the target peak.

[0078] Specifically, all groups of continuous data points that meet the conditions of increasing first and then decreasing are identified, and for each group of such data points, the point corresponding to its maximum value is marked as a wave crest. All data points in the ultrasonic echo signal that are greater than the first wave threshold are checked one by one to determine the target wave crest, and there is at least one target wave crest.

[0079] In this embodiment, the method screens out data points in the ultrasonic echo that are greater than the first wave threshold, and identifies the formation of a wave peak by judging whether these data points have a trend of first increasing and then decreasing, and marks the maximum value among the continuous data points as the wave peak of a wave, traversing the data points in the entire ultrasonic echo that are greater than the first wave threshold, and determining the target wave peak. This method can effectively identify the secondary oscillation phenomenon in the ultrasonic echo, thereby reducing the measurement deviation caused by misjudgment of the wave peak amplitude.

[0080] In one embodiment, Figure 4 As shown, determining the second wave peak segment includes the following steps:

[0081] Step 401: according to the order in which the target peaks appear, determine the last peak in the first peak segment and use it as the reference peak;

[0082] Specifically, in the ultrasonic echo signal, the peak segment refers to a series of continuous peaks, and the last peak in the first peak segment is determined according to the order in which the target peaks appear. This peak is called the reference peak, marking the end of the first peak segment.

[0083] Step 402: Obtain the position of the reference peak, and use the peak segment consisting of all peaks after the position of the reference peak in the target peak as the second peak segment.

[0084] Specifically, the reference peak is the last peak in the first peak segment. The second peak segment consists of all peaks after the reference peak. This means that from the peak after the reference peak until the end of the next significant peak segment, all peaks belong to the second peak segment.

[0085] In this embodiment, according to the order in which the target peaks appear, the last peak in the first peak segment is accurately determined and defined as the reference peak. By obtaining the specific position of the reference peak, the peak segment consisting of all peaks after the reference peak is identified as the second peak segment. This method provides a solid foundation for further analysis and identification of the secondary initiation phenomenon in ultrasonic echoes by clearly distinguishing the two peak segments.

[0086] In one embodiment, identifying whether there is secondary oscillation in the ultrasonic echo according to the first target amplitude and the second target amplitude includes:

[0087] If the height difference between the first target amplitude and the first wave threshold is smaller than the height difference between the second target amplitude and the first wave threshold, then secondary oscillation exists in the ultrasonic echo;

[0088] Specifically, the maximum peak value in the first peak segment is used as the first target amplitude, and the maximum peak value in the second peak segment is used as the second target amplitude. Secondary onset may refer to the echo reaching the amplitude for the first time, starting to decay, and then onset again, and the height after the second onset exceeds the amplitude of the first onset. The height difference between the first target amplitude and the first wave threshold and the height difference between the second target amplitude and the first wave threshold can be calculated and compared. If the height difference between the first target amplitude and the first wave threshold is smaller than the height difference between the second target amplitude and the first wave threshold, secondary onset occurs.

[0089] or,

[0090] If the second target amplitude is greater than the first target amplitude, secondary oscillation exists in the ultrasonic echo.

[0091] Specifically, if the second target amplitude is greater than the first target amplitude, it indicates that an increase in amplitude occurs again after the echo signal attenuates, that is, secondary oscillation exists in the ultrasonic echo.

[0092] In this embodiment, the height difference between the first target amplitude and the first wave threshold is compared to see whether it is smaller than the height difference between the second target amplitude and the first wave threshold. If the height difference between the first target amplitude and the first wave threshold is smaller than the height difference between the second target amplitude and the first wave threshold, it is considered that secondary oscillation exists; or directly compare whether the second target amplitude is larger than the first target amplitude. If the second target amplitude is larger, it indicates that secondary oscillation exists. This method can accurately identify abnormal secondary oscillation phenomenon in ultrasonic echo, which is crucial to ensure the measurement accuracy of ultrasonic flowmeter.

[0093] In one embodiment, Figure 5 As shown, the method further comprises the following steps:

[0094] Step 501: if it is identified that there is secondary oscillation in the ultrasonic echo, the nominal resonant frequency of the transducer in the ultrasonic flow meter is obtained;

[0095] Specifically, by analyzing the ultrasonic echo signal, identify whether there is a secondary oscillation phenomenon. Secondary oscillation means that the echo attenuates after reaching the amplitude for the first time, and then oscillates again, and the height of the second oscillation exceeds the amplitude of the first oscillation. Once the existence of secondary oscillation is confirmed, the nominal resonant frequency of the transducer in the ultrasonic flowmeter is obtained. The transducer is a device used to transmit and receive ultrasonic signals in an ultrasonic flowmeter. The nominal resonant frequency can refer to the frequency at which the transducer reaches the maximum amplitude response under ideal or standard conditions. The nominal resonant frequency is usually determined when the transducer is designed and can be found in the technical documentation or product specifications.

[0096] Step 502: determining an excitation frequency adjustment interval of the transducer according to the nominal resonant frequency; wherein the nominal resonant frequency is the center of the excitation frequency adjustment interval;

[0097] Specifically, the nominal resonant frequency refers to the resonant frequency of the transducer under ideal or standard conditions. This is the frequency preset when the transducer is designed, and is usually used to ensure that the transducer works at the highest efficiency. The excitation frequency adjustment interval refers to the excitation frequency range in which the transducer can work normally. This interval is centered on the nominal resonant frequency and extends upward and downward to a certain range to adapt to frequency deviations caused by environmental changes and equipment aging. When the ambient temperature and temperament change, or the transducer ages, the actual resonant frequency of the transducer may deviate from its nominal value, and the excitation frequency needs to match the current resonant frequency of the transducer. If the mismatch between the excitation frequency and the resonant frequency exceeds a certain degree, the transducer may not work effectively, or even produce secondary oscillation.

[0098] Step 503: adjusting the excitation frequency of the transducer based on the excitation frequency adjustment interval.

[0099] Specifically, the excitation frequency adjustment interval refers to the excitation frequency range in which the transducer can work normally. This interval is centered on the nominal resonant frequency and extends upward and downward to a certain range to adapt to frequency deviations caused by environmental changes and equipment aging. By dynamically adjusting the excitation frequency of the transducer, it is ensured that the transducer works near the optimal resonant frequency and reduces the secondary oscillation phenomenon caused by frequency mismatch.

[0100] In this embodiment, when the method identifies the presence of secondary oscillation in the ultrasonic echo, it first obtains the nominal resonant frequency of the transducer and determines an excitation frequency adjustment interval centered on the frequency. The excitation frequency adjustment interval takes into account the frequency offset that may be caused by environmental changes and equipment aging, ensuring that the transducer can operate within a reasonable frequency range. The excitation frequency of the transducer is adjusted within the adjustment interval to find an optimal operating point, thereby reducing or eliminating the secondary oscillation phenomenon. The method adapts to environmental changes and equipment aging by dynamically adjusting the excitation frequency, ensuring that the transducer always operates in the best condition and reducing measurement errors.

[0101] In one embodiment, Figure 6 As shown, adjusting the excitation frequency of the transducer based on the excitation frequency adjustment range includes the following steps:

[0102] Step 601: taking the nominal resonant frequency as the starting point within the excitation frequency adjustment range, adjusting the excitation frequency upward with the first step length and adjusting the excitation frequency downward with the second step length in an alternating order to obtain a first frequency and a second frequency; wherein the frequency obtained by adjusting the excitation frequency upward is recorded as the first frequency, and the frequency obtained by adjusting the excitation frequency downward is recorded as the second frequency;

[0103] Specifically, the nominal resonant frequency of a general transducer is 200kHz, 500kHz, etc. If a transducer with a nominal resonant frequency of 500kHz is used, its adjustment range is generally 450kHz~550kHz, and its step size is generally 1~5kHz. For example, assuming that the nominal resonant frequency of the transducer is 500kHz, the first step size is set to 5kHz, the upper limit of the adjustment range is 550kHz, and the lower limit is 450kHz. Taking 500kHz as the starting point, the excitation frequency is adjusted upward to 505kHz with the first step size of 5kHz to obtain a first frequency. Taking 500kHz as the starting point, the excitation frequency is adjusted downward to 495kHz with the second step size of 5kHz to obtain a second frequency. The excitation frequency is adjusted upward to 510kHz to obtain a first frequency, and the excitation frequency is adjusted downward to 490kHz to obtain a second frequency. And so on, until the entire adjustment range is covered, that is, the excitation frequency is adjusted upward to 550kHz and the excitation frequency is adjusted downward to 450kHz.

[0104] Step 602: Determine a target excitation frequency based on at least one of the first frequency and the second frequency, and use the target excitation frequency as the excitation frequency after the transducer is adjusted.

[0105] Specifically, the target excitation frequency is determined based on at least one of the first frequency and the second frequency obtained in step 601, that is, at least one suitable frequency is selected from all the adjusted first frequencies and second frequencies as the target excitation frequency. It should be noted that before determining the target excitation frequency, it is necessary to test and verify each first frequency and second frequency, that is, analyze the response of each first frequency and second frequency, which may include factors such as signal strength, stability, and whether secondary oscillation occurs. If at least one of the first frequency or the second frequency exhibits better performance or no secondary oscillation occurs, the frequency can be selected as the target excitation frequency. After determining the target excitation frequency, the target excitation frequency can be used as the excitation frequency after the transducer is adjusted.

[0106] In this embodiment, within the excitation frequency adjustment interval, the excitation frequency is adjusted upward and downward alternately with a set step size, starting from the nominal resonant frequency of the transducer, so as to obtain a first frequency and a second frequency. The frequency obtained by upward adjustment is recorded as the first frequency, and the frequency obtained by downward adjustment is recorded as the second frequency. Based on at least one of the first frequency and the second frequency, the target excitation frequency is determined and set as the excitation frequency after the transducer is adjusted. The effect of this method is that the entire excitation frequency adjustment interval can be scanned in detail. By selecting the best performing frequency as the target excitation frequency, the working state of the transducer can be optimized, and the secondary oscillation phenomenon can be reduced or avoided, thereby improving the measurement accuracy of the ultrasonic flowmeter and the overall performance of the equipment.

[0107] In one embodiment, Figure 7 As shown, determining the target excitation frequency based on at least one of the first frequency and the second frequency includes the following steps:

[0108] Step 701: Each time the excitation frequency is adjusted once to obtain a first frequency or a second frequency, the transducer is driven with the first frequency or the second frequency, and when the first frequency or the second frequency is used as the excitation frequency, it is identified whether there is a secondary vibration in the ultrasonic echo of the ultrasonic flow meter, and a secondary vibration identification result corresponding to the first frequency or a secondary vibration identification result corresponding to the second frequency is obtained;

[0109] Specifically, after each adjustment of the excitation frequency, the first frequency or the second frequency obtained after the adjustment is used to drive the transducer, and the frequency is used as the excitation frequency to identify whether there is secondary oscillation in the ultrasonic echo of the ultrasonic flowmeter. Further, this step can obtain the secondary oscillation identification result corresponding to the first frequency or the secondary oscillation identification result corresponding to the second frequency. That is, each adjustment of the excitation frequency is accompanied by a test to determine whether the frequency will cause secondary oscillation.

[0110] Step 702: Based on the secondary oscillation identification result, one of the first frequency or the second frequency is determined as the target excitation frequency; wherein, within the excitation frequency adjustment range, the excitation frequency is adjusted upward with the first step size and downward with the second step size in an alternating order, and the upward and downward adjustments are continuously cycled until the target excitation frequency is determined based on the secondary oscillation identification result.

[0111] Specifically, within the excitation frequency adjustment interval, starting from the nominal resonant frequency, the excitation frequency is adjusted upward with the first step size and downward with the second step size alternately. After each adjustment of the excitation frequency, the transducer can be driven with the newly obtained frequency (the first frequency or the second frequency), and the ultrasonic echo is detected to identify whether there is a secondary initiation. This process will be repeated alternately, that is, a detection will be performed after each adjustment of the excitation frequency until a frequency is found so that the secondary initiation identification result based on the frequency indicates that there is no secondary initiation or the influence of the secondary initiation is minimized. If the frequency exists, whether in the process of adjusting the excitation frequency upward or downward, the frequency can be determined as the target excitation frequency, and the subsequent adjustment and test cycle will stop.

[0112] In this embodiment, first within the excitation frequency adjustment interval, starting from the nominal resonant frequency, the excitation frequency is alternately adjusted up and down with a preset step size, and the frequencies obtained after each adjustment are respectively referred to as the first frequency and the second frequency. These frequencies are used to drive the transducer respectively, and when these frequencies are used as excitation frequencies, it is identified whether there is secondary oscillation in the ultrasonic echo of the ultrasonic flowmeter, thereby obtaining a secondary oscillation identification result corresponding to each frequency. Based on the identification results, a frequency that does not cause or minimizes secondary oscillation is selected as the target excitation frequency. This process will continue to cycle until a frequency that meets the conditions is found. This method can dynamically adjust the excitation frequency to adapt to the impact of environmental changes or equipment aging, ensure that the transducer always works in the best state, and reduce or avoid the occurrence of secondary oscillation.

[0113] In one embodiment, the method further includes identifying whether there is secondary oscillation in the ultrasonic echo of the ultrasonic flow meter if at least one of the following conditions is met:

[0114] The first condition: the change in the working temperature of the ultrasonic flowmeter is greater than the temperature threshold;

[0115] Specifically, the operating temperature of an ultrasonic flowmeter has a significant impact on its performance. Changes in temperature may affect the material properties of the transducer, thereby changing its resonant frequency. The temperature threshold is a preset value used to determine whether the temperature change is large enough to cause a significant change in the resonant frequency of the transducer, which may cause secondary oscillation. Ultrasonic flowmeters are usually equipped with temperature sensors to monitor their operating temperature in real time. If there is a large deviation between the current temperature and the previously recorded temperature, it means that the operating temperature has changed, and a secondary oscillation detection is performed.

[0116] The second condition: the change in the sound velocity in the ultrasonic flow meter is greater than the sound velocity threshold;

[0117] Specifically, in an ultrasonic flow meter, the speed of sound refers to the speed at which ultrasonic waves propagate in a medium (such as a gas or liquid). Changes in the speed of sound directly affect the propagation time of the ultrasonic signal, thereby affecting the flow measurement results. The speed of sound threshold is a preset value used to determine whether the change in the speed of sound is large enough to cause a significant change in the characteristics of the ultrasonic echo, which may cause secondary initiation. By comparing the currently measured speed of sound with the reference speed of sound, the change in the speed of sound can be calculated. If the change in the speed of sound exceeds the preset speed of sound threshold, this indicates that the characteristics of the medium have changed significantly, which may affect the propagation of the ultrasonic signal and the performance of the transducer, so it is necessary to check whether secondary initiation exists.

[0118] The third condition: the ultrasonic flow meter is powered on again;

[0119] Specifically, repowering can refer to the process of an ultrasonic flow meter being powered on again and resuming its working state after being powered off or in standby mode. When an ultrasonic flow meter is powered on again, it goes through a series of self-test and initialization processes to ensure that all components and functions are working properly. Repowering may cause changes in the device state, and these changes may affect the propagation and echo characteristics of the ultrasonic signal. Detecting secondary oscillation after powering on again can ensure that the flow meter can provide accurate flow measurement under various operating conditions and reduce potential errors caused by changes in the device state.

[0120] The fourth condition: the timing time of reaching the ultrasonic flow meter.

[0121] Specifically, the timing time can refer to the time point at which the ultrasonic flow meter automatically performs a specific task according to a preset cycle or specific time interval. This can be a time-based trigger mechanism, for example, once a day, once a week, or at a specific hour. When the timing time is reached, the flow meter may perform a system self-check to check the hardware status, software operation, and sensor accuracy. Reaching the timing time may also be a condition that triggers the detection of whether there is a secondary oscillation in the ultrasonic echo. This is because periodic checks help to promptly detect and correct problems that may affect measurement accuracy.

[0122] In one embodiment, Figure 8 As shown, determining the change value of the sound velocity in the ultrasonic flow meter includes the following steps:

[0123] Step 801: Obtain the flight time and flight distance of the first wave of the target in the ultrasonic echo;

[0124] Specifically, the target first wave refers to the ultrasonic wave crest that is first reflected from an obstacle on the measurement path (such as a pipe wall) after being emitted from the transducer. The flight time refers to the total time from the emission of the ultrasonic wave to the reception of the ultrasonic wave. This can be achieved by measuring the time difference between the emission and return of the ultrasonic signal, usually using the time difference (TDC) technique for accurate measurement. The flight distance refers to the path length of the ultrasonic wave propagating in the medium. In a flow meter, this is usually a fixed distance between the transducers.

[0125] Step 802: Determine the target sound speed according to the flight time and the flight distance;

[0126] Specifically, the flight time and flight distance of the target's first wave in the ultrasonic echo have been obtained. Using the formula Calculate target sound speed v .

[0127] in, v is the target sound speed, d is the flight distance, t It's flight time.

[0128] Step 803: The difference between the target sound velocity and the reference sound velocity is used as the change value of the sound velocity in the ultrasonic flow meter.

[0129] Specifically, the target sound speed is the sound speed obtained under the current measurement conditions, and the reference sound speed is the sound speed obtained by preset or standard conditions, which is usually used for calibration or comparison. The sound speed change value is the difference between the target sound speed and the reference sound speed.

[0130] In the above embodiment, the method identifies the secondary vibration phenomenon by monitoring the changes of multiple key parameters. When the change value of the working temperature of the ultrasonic flowmeter exceeds the preset temperature threshold, the change value of the sound velocity exceeds the preset sound velocity threshold, the flowmeter is powered on again, or the set timing time is reached, one or more of these is triggered to identify whether there is secondary vibration in the ultrasonic echo. By comprehensively considering multiple factors such as temperature, sound velocity, equipment startup, and timing tasks, it is possible to more comprehensively monitor changes in environmental and operating conditions that may cause secondary vibration, thereby improving the accuracy and timeliness of identifying secondary vibration.

[0131] In one embodiment, obtaining an ultrasonic echo of an ultrasonic flowmeter includes: obtaining the ultrasonic echo of the ultrasonic flowmeter by sampling, extracting the amplitude of the ultrasonic echo, and determining whether the amplitude of the ultrasonic echo is within a valid range; if not, performing gain adjustment on the ultrasonic echo based on an amplification circuit to control the amplitude of the ultrasonic echo. ADC sampling can obtain the entire waveform in one sampling.

[0132] Specifically, the amplitude of an ultrasonic echo signal refers to the maximum amplitude of a signal, and the amplitude of an ultrasonic echo signal can reflect the energy of an ultrasonic wave when it is reflected by an obstacle. The extracted amplitude needs to be compared with a preset effective range to determine whether the echo signal is within the effective range. If the amplitude of the ultrasonic echo is within the effective range, it is directly extracted. If it is found that the amplitude of the ultrasonic echo is not within the effective range, that is, the amplitude is too large or too small. When the echo amplitude exceeds the effective range, it is necessary to perform gain adjustment on the amplifier circuit to control the echo amplitude so that it returns to the effective range. Gain adjustment refers to adjusting the amplification factor of the amplifier circuit to control the amplitude of the received ultrasonic echo signal. If the echo amplitude is too small, the gain needs to be increased to amplify the signal; if the echo amplitude is too large, the gain needs to be reduced to reduce the signal amplitude.

[0133] In this embodiment, the echo signals of the ultrasonic flow meter are obtained, the amplitudes of these echo signals are extracted, and it is determined whether these amplitudes are within the preset effective range; if the amplitude is not within the effective range, that is, too small or too large, the amplitude of the echo signal is controlled by adjusting the gain of the amplifier circuit to return it to the appropriate range. This process ensures the quality of the signal and provides reliable data for subsequent flow calculation and analysis.

[0134] It should be understood that, although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0135] In one embodiment, an ultrasonic flow meter is provided, including a memory and a processor. The ultrasonic flow meter may be a terminal, and its internal structure diagram may be as follows: Fig. 9 As shown. The ultrasonic flowmeter includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the ultrasonic flowmeter is used to provide computing and control capabilities. The memory of the ultrasonic flowmeter includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the ultrasonic flowmeter is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a method for identifying the secondary oscillation of an ultrasonic echo for an ultrasonic flowmeter is implemented. The display screen of the ultrasonic flowmeter can be a liquid crystal display screen or an electronic ink display screen, and the input device of the ultrasonic flowmeter can be a touch layer covered on the display screen, or a button, a trackball or a touchpad set on the shell of the ultrasonic flowmeter, or an external keyboard, touchpad or mouse, etc.

[0136] Those skilled in the art will understand that Fig. 9 The structure shown in the figure is merely a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the ultrasonic flowmeter to which the scheme of the present application is applied. The specific ultrasonic flowmeter may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0137] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0138] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for identifying secondary oscillation of ultrasonic echo of ultrasonic flowmeter, characterized in that: The method comprises: Acquire ultrasonic echo of ultrasonic flow meter; Based on the ultrasonic echo, a target peak is determined; wherein the target peak is a peak of a wave in the ultrasonic echo that is greater than a first wave threshold; According to the order in which the target peaks appear, the peak values ​​of the target peaks are retrieved. If there are a plurality of first peak segments in which the peak values ​​first increase and then decrease in the target peaks, the maximum value of the peaks in the first peak segment is recorded as the first target amplitude; According to the order in which the target peaks appear, the peak value of the second peak segment in the target peak is retrieved. If there are multiple consecutive peak values ​​in the second peak segment that first increase and then decrease, the maximum value of the peaks in the second peak segment is recorded as the second target amplitude; wherein the second peak segment is a peak segment composed of peaks in the target peak that are located after the first peak segment; According to the first target amplitude and the second target amplitude, identify whether there is a secondary oscillation in the ultrasonic echo; wherein the secondary oscillation refers to that the ultrasonic echo reaches the amplitude for the first time, starts to attenuate, and then oscillates again, and the height after the second oscillation exceeds the amplitude of the first oscillation.

2. The ultrasonic echo secondary oscillation identification method for an ultrasonic flowmeter according to claim 1, characterized in that: Traversing the ultrasonic echo to determine the target peak includes: Filter out data points in the ultrasonic echo that are greater than a first wave threshold; Determine whether there are consecutive data points that first increase and then decrease. If so, record the maximum value among the consecutive data points as a wave peak; The data points in the ultrasonic echo are traversed to determine the target peak.

3. The ultrasonic echo secondary oscillation identification method for an ultrasonic flowmeter according to claim 1, characterized in that: Determining the second wave peak section includes: According to the order in which the target peaks appear, determine the last peak in the first peak segment and use it as the reference peak; The position of the reference peak is obtained, and a peak segment consisting of all peaks after the position of the reference peak in the target peak is used as a second peak segment.

4. The ultrasonic echo secondary oscillation identification method for an ultrasonic flowmeter according to claim 1, characterized in that: Identifying whether secondary oscillation exists in the ultrasonic echo according to the first target amplitude and the second target amplitude includes: If the height difference between the first target amplitude and the first wave threshold is smaller than the height difference between the second target amplitude and the first wave threshold, then secondary oscillation exists in the ultrasonic echo; or, If the second target amplitude is greater than the first target amplitude, secondary oscillation exists in the ultrasonic echo.

5. The ultrasonic echo secondary oscillation identification method for an ultrasonic flowmeter according to any one of claims 1 to 4, characterized in that: The method further comprises: If secondary oscillation is identified in the ultrasonic echo, a nominal resonant frequency of the transducer in the ultrasonic flow meter is obtained; Determining an excitation frequency adjustment interval of the transducer according to the nominal resonant frequency; wherein the nominal resonant frequency is the center of the excitation frequency adjustment interval; The excitation frequency of the transducer is adjusted based on the excitation frequency adjustment interval.

6. The ultrasonic echo secondary oscillation identification method for an ultrasonic flowmeter according to claim 5, characterized in that: Adjusting the excitation frequency of the transducer based on the excitation frequency adjustment interval includes: Taking the nominal resonant frequency as a starting point within the excitation frequency adjustment interval, the excitation frequency is adjusted upward with a first step length and adjusted downward with a second step length in an alternating order to obtain a first frequency and a second frequency; wherein the frequency obtained by adjusting the excitation frequency upward is recorded as the first frequency, and the frequency obtained by adjusting the excitation frequency downward is recorded as the second frequency; A target excitation frequency is determined based on at least one of the first frequency and the second frequency, and the target excitation frequency is used as the excitation frequency after the transducer is adjusted.

7. The ultrasonic echo secondary oscillation identification method for an ultrasonic flowmeter according to claim 6, characterized in that: Determining a target excitation frequency based on at least one of the first frequency and the second frequency includes: Each time the excitation frequency is adjusted once, a first frequency or a second frequency is obtained, the transducer is driven with the first frequency or the second frequency, and when the first frequency or the second frequency is used as the excitation frequency, it is identified whether there is a secondary oscillation in the ultrasonic echo of the ultrasonic flow meter, and a secondary oscillation identification result corresponding to the first frequency or a secondary oscillation identification result corresponding to the second frequency is obtained; Based on the secondary oscillation identification result, one of the first frequency or the second frequency is determined as the target excitation frequency; wherein, within the excitation frequency adjustment range, taking the nominal resonant frequency as the starting point, the excitation frequency is adjusted upward with the first step size and downward with the second step size in an alternating order, and the upward and downward adjustments are continuously cycled until the target excitation frequency is determined based on the secondary oscillation identification result.

8. The ultrasonic echo secondary oscillation identification method for an ultrasonic flowmeter according to any one of claims 1 to 4, characterized in that: The method further includes: identifying whether there is secondary oscillation in the ultrasonic echo of the ultrasonic flowmeter if at least one of the following is satisfied: The operating temperature change value of the ultrasonic flowmeter is greater than the temperature threshold; The change value of the sound velocity in the ultrasonic flow meter is greater than the sound velocity threshold; The ultrasonic flow meter is powered on again; The timing time of reaching the ultrasonic flow meter; Wherein, determining the change value of the speed of sound in the ultrasonic flowmeter includes: Obtain the flight time and flight distance of the first wave of the target in the ultrasonic echo, determining a target sound speed according to the flight time and the flight distance; The difference between the target sound velocity and the reference sound velocity is used as the change value of the sound velocity in the ultrasonic flow meter.

9. The ultrasonic echo secondary oscillation identification method for an ultrasonic flowmeter according to any one of claims 1 to 4, characterized in that: Obtain ultrasonic echo of ultrasonic flow meter, including: Acquire the ultrasonic echo of the ultrasonic flow meter by sampling; Extracting the amplitude of the ultrasonic echo and determining whether the amplitude of the ultrasonic echo is within a valid range; If not, the ultrasonic echo is gain-adjusted based on an amplifier circuit to control the amplitude of the ultrasonic echo.

10. An ultrasonic flow meter, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the ultrasonic echo secondary oscillation identification method for an ultrasonic flow meter according to any one of claims 1 to 9 are implemented.

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