Ultrasonic head wave positioning method, device and equipment

Abstract

The invention discloses an ultrasonic head wave positioning method, device and equipment, and the method specifically comprises the steps: determining the head wave threshold value ratio of a transducer, the head wave threshold value ratio is determined according to the characteristics of the transducer, and specifically comprises the steps: calculating according to the head wave threshold value and the head wave amplitude value or the head wave threshold value and the maximum amplitude value of the transducer in a zero flow state; and selecting an initial value of a head wave threshold value, measuring a maximum amplitude value and a head wave amplitude value, and updating the head wave threshold value. Whether wrong waves occur is judged according to the relation between the head wave threshold value and the head wave amplitude value or the relation between the head wave threshold value and the maximum amplitude value, then the head wave amplitude value is adjusted, the head wave position is accurately positioned, and time measurement errors caused by wrong waves are avoided. According to the invention, accurate threshold value updating can be realized only by adding an amplitude value measuring unit or utilizing the existing amplitude value measuring unit and cooperating with a head wave threshold value ratio register and a judgment mechanism of the head wave threshold value ratio register.

Description

Technical Field

[0001] The present invention relates to the field of ultrasonic measurement technology, and in particular to an ultrasonic first wave positioning method, device and equipment. Background Art

[0002] With the development of fluid metering technology, ultrasonic detection and metering methods are widely used in various fields. Ultrasonic metering is a method of transmitting ultrasonic signals to the medium to be detected and receiving echo signals, and realizing metering based on information such as the time delay and amplitude change of the echo signals. Therefore, it has high requirements for the first wave detection accuracy in the ultrasonic echo signal.

[0003] Ultrasonic time difference method is a common method for measuring medium flow. Its principle is to use the time difference of ultrasonic wave in the downstream direction and upstream direction in the medium, which is proportional to the average flow rate of the gas. The gas flow rate is calculated by calculating the relationship between the propagation time difference of ultrasonic wave and the propagation distance. Therefore, it is very important to accurately measure the propagation time of ultrasonic wave between the transmitting and receiving transducers. There are two main ways to implement the time difference method, namely the cross-correlation method and the zero-crossing detection method. The former collects the received waveform through the digital-to-analog conversion circuit, and then calculates the time difference by cross-correlating the upstream and downstream waveforms; the latter compares the received signal with the zero position, triggers the timer to stop timing when the echo passes the zero position to measure the propagation time of the ultrasonic pulse, and then calculates the time difference by subtracting the propagation time of the upstream and downstream. The cross-correlation method calculates the time difference through software, and the zero-crossing detection method measures the time difference through hardware. It has certain advantages in terms of power consumption, complexity, and cost, and is widely used in flow measurement instruments such as ultrasonic water meters and ultrasonic gas meters. However, when there is interference in the received signal or the amplitude changes greatly, the zero-crossing detection method will be challenged. How to accurately measure the propagation time is a key issue.

[0004] The key to accurately measuring the propagation time is to accurately locate the first wave. At present, the first wave positioning methods in the zero-crossing detection method mainly include the double threshold method, the pulse width ratio method, the time window method and the double pulse sequence method. The double threshold method refers to setting a first wave detection level. The first waveform higher than the level is the first wave. When the first wave is detected, the level returns to zero to measure the time of zero crossing; the pulse width ratio method is to calculate the ratio of the width of the first wave in the double threshold method to the width of the nth zero-position waveform. By comparing this ratio, the first wave level can be set more reasonably. Both methods are relative positioning methods, that is, a waveform can be found as the first wave, but it is impossible to determine which one it is. When the amplitude of the echo signal changes drastically or there is obvious noise, both methods may have the problem of detecting the wrong first wave. The time window method refers to setting a time window and only detecting the echo signal within the window, thereby avoiding the problem of first wave detection. However, when the sound velocity of the medium changes, the time window is difficult to accurately follow the change, and wrong waves will also appear. The double pulse sequence method refers to transmitting two pulse sequences with a certain phase difference. The waveform received by the receiving transducer will be deformed at the place of this phase difference, and the first wave is located by detecting this deformation. Although this method can locate the first wave to a certain extent, when the temperature or signal attenuation changes the transducer characteristics, the deformation characteristics will also change or become less obvious, resulting in failure to locate the first wave.

[0005] In the flow measurement of gas, there are many factors that interfere with accurate measurement, such as medium changes, temperature changes, sound speed changes, signal strength changes, etc. The present invention aims to propose a method that can not only absolutely locate the first wave, but also can work stably under the conditions of drastic signal changes, noise interference, temperature-affected changes in transducer characteristics, etc. Summary of the invention

[0006] The content of the invention introduces a series of simplified concepts, which will be further described in detail in the detailed description. The content of the invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0007] To at least partially solve the above problems, an ultrasonic head wave positioning method includes:

[0008] determining a first wave threshold ratio of the transducer;

[0009] Select the initial value of the first wave threshold;

[0010] Measure amplitude, including maximum amplitude and first wave amplitude;

[0011] Update the first wave threshold.

[0012] Preferably, the method further includes judging the quality of the first wave threshold.

[0013] Preferably, the method further includes updating the first wave threshold ratio.

[0014] Preferably, the first wave threshold ratio is determined according to the characteristics of the transducer, and specifically includes calculation based on the first wave threshold and the first wave amplitude or the first wave threshold and the maximum amplitude of the transducer under a zero flow state.

[0015] In a first aspect, the present invention provides an ultrasonic first wave positioning method, which specifically includes:

[0016] Determine the first wave threshold ratio R of the transducer M ;

[0017] Select the initial value V of the first wave threshold F0 ;

[0018] Measure the amplitude and measure the maximum amplitude A through the amplitude measurement circuit Max ;

[0019] Update the first wave threshold V' F , according to the measured maximum amplitude A Max R M Calculate the first wave threshold V' F .

[0020] Preferably, the first wave threshold V' F =R M *A Max .

[0021] Preferably, the first wave threshold ratio R of the transducer is determined M The methods specifically include:

[0022] Obtain an initialization value, which is determined according to the transducer characteristic curve under zero flow state, wherein the initialization value includes the first wave amplitude A F , first wave number and maximum amplitude A Max0 ;

[0023] Calculate the first wave threshold V F , the first wave threshold V F A is the amplitude of the first wave F and the average of the amplitude of the wave before the first wave number;

[0024] Determine the first wave threshold ratio R M The specific calculation method is

[0025]

[0026] Beneficial effects of this solution: using the first wave threshold ratio R MIn the steady flow state, the fluctuation is small due to the changes in temperature, medium type, and sound wave scattering / diffraction. When a wrong wave occurs, it will suddenly increase or decrease. Only the maximum amplitude and the first wave threshold ratio R are used. M , it is possible to determine whether a wrong wave occurs and locate the first wave as quickly as possible.

[0027] In a second aspect, the present invention provides an ultrasonic first wave positioning method, which specifically includes:

[0028] Determine the first wave threshold ratio R of the transducer M and the second first wave threshold ratio R F , set R F Error range R F-min ~R F-max ;

[0029] Select the initial value V of the first wave threshold F0 ;

[0030] Measure the amplitude, measure the first wave amplitude A through the amplitude measurement circuit F and maximum amplitude A Max ;

[0031] To judge the quality of the first wave threshold, if

[0032]

[0033] , then the first wave threshold V′ F =R F *A F ;like

[0034]

[0035] or

[0036]

[0037] , then the first wave threshold V' F =R M *A Max ;

[0038] Update the first wave threshold.

[0039] Preferably, the first wave threshold ratio R of the transducer is determined M and the second first wave threshold ratio R F The methods specifically include:

[0040] Obtain an initialization value, which is determined according to the transducer characteristic curve under zero flow state, wherein the initialization value includes the first wave amplitude A F , first wave number and maximum amplitude A M ax0;

[0041] Calculate the first wave threshold V F , the first wave threshold V F A is the amplitude of the first wave F and the average of the amplitude of the wave before the first wave number;

[0042] Determine the first wave threshold ratio R M The specific calculation method is

[0043]

[0044] Determine the second first wave threshold ratio R F The specific calculation method is

[0045] .

[0047] Beneficial effects of this solution: using the first wave threshold ratio R M and the second first wave threshold ratio R F Under steady flow conditions, the fluctuations are small due to temperature, medium type, and sound wave scattering / diffraction. When a wrong wave occurs, it will suddenly increase or decrease. Under the same steady flow conditions, R F The stability is higher than R M , determine R F Reasonable error range is used as the basis for judging the wrong wave, combined with the measured first wave amplitude A F Predict the next first wave threshold. When a wrong wave is found, use R M Finding the correct threshold value can accurately track the drift of the first wave threshold ratio of the transducer and can also accurately locate the first wave in a timely manner.

[0048] In a third aspect, the present invention provides an ultrasonic first wave positioning method, which specifically comprises: determining the first first wave threshold ratio R of the transducer M and the second first wave threshold ratio R F , set R M Error range R M-min ~R M-max , set R F Error range R F-min ~R F-max ;

[0049] Select the initial value V of the first wave threshold F0 ;

[0050] Measure the amplitude, measure the first wave amplitude A through the amplitude measurement circuit F and maximum amplitude A Max ;

[0051] To judge the quality of the first wave threshold, if

[0052]

[0053] , then the first wave threshold V′ F =R F *A F ;like

[0054]

[0055] or

[0056]

[0057] , then the first wave threshold V' F =R M *A Max ;

[0058] Update the first wave threshold;

[0059] Update the first wave threshold ratio R M ,like

[0060]

[0061] and

[0062]

[0063] ,but ;

[0065] Update the first wave threshold ratio.

[0066] Preferably, the first first wave threshold ratio R M Or the second first wave threshold ratio R F It is the average value under different operating temperatures.

[0067] Preferably, the R F The range is 0.5~0.9.

[0068] Preferably, the R F Preferred is 0.7.

[0069] Beneficial effects of this solution: Based on the previous solution, R M As a floating parameter, it has a stronger ability to suppress drift.

[0070] In a fourth aspect, the present invention also provides an ultrasonic first wave positioning device, comprising a transducer, a signal conditioning unit, a first wave threshold unit, a comparator, a timing unit, an amplitude measurement unit, a post-processing unit and a threshold prediction unit; the transducer is used to receive an ultrasonic echo signal and send it to the signal conditioning unit; the signal conditioning unit is used to perform noise reduction and scaling processing on the ultrasonic echo signal and send it to the comparator; the first wave threshold unit is used to receive and store a variable threshold and send it to the comparator; the comparator compares the data sent by the signal conditioning unit and the first wave threshold unit, and outputs a signal with a waveform higher than the first wave threshold to the timing unit, returns the first wave threshold to a zero reference voltage, and performs zero crossing detection; the timing unit records the zero crossing time and sends it to the post-processing unit for analysis; the amplitude measurement unit is used to measure the first wave amplitude and the maximum amplitude; the threshold prediction unit calculates and predicts the next first wave threshold based on the data measured by the amplitude measurement unit, and feeds the predicted first wave threshold back to the first wave threshold unit.

[0071] Preferably, the threshold prediction unit includes a first first-wave threshold ratio register and a second first-wave threshold ratio register, which receive the maximum amplitude, the first-wave amplitude and the latest first-wave threshold sent by the amplitude measurement unit and the post-processing unit, and send the next first-wave threshold.

[0072] Beneficial effects of this solution: This solution adds an amplitude measurement unit, and can also use the existing amplitude measurement unit, in conjunction with the first wave threshold ratio and its judgment mechanism, to achieve the effect of accurately locating the first wave by updating the threshold through software or hardware.

[0073] In a fifth aspect, the present invention further provides an electronic device, the device comprising:

[0074] one or more processors;

[0075] a storage device for storing one or more programs,

[0076] When the one or more programs are executed by the one or more processors, the one or more processors implement an ultrasonic head wave positioning method as described in any one of claims 1 to 14.

[0077] Beneficial effects of this scheme: This scheme adopts a non-relative positioning method, which can accurately locate the first wave position and avoid the time measurement error introduced by the wrong wave. It has strong anti-interference ability and adaptability. Even if the wrong wave occurs due to external interference or environmental changes, it can be restored immediately at the next measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] The following drawings of the present invention are used to understand the present invention as part of the present invention. Embodiments of the present invention are shown in the drawings and the description thereof is used to explain the principle of the present invention.

[0079] In the attached figure:

[0080] Figure 1 This is a flow chart of an ultrasonic head wave positioning method in Embodiment 1 of the present invention;

[0081] Figure 2 This is a flow chart of an ultrasonic head wave positioning method in Embodiment 2 of the present invention;

[0082] Figure 3 This is a flow chart of a method for determining a first first wave threshold ratio of a transducer in Embodiment 2 of the present invention;

[0083] Figure 4 This is a diagram showing the variation regularity of the amplitude envelope of an ultrasonic head wave positioning method in the second embodiment of the present invention;

[0084] Figure 5 This is a characteristic diagram of the first wave threshold ratio of an ultrasonic first wave positioning method in Embodiment 2 of the present invention;

[0085] Figure 6 It is a schematic diagram of the head wave positioning principle of an ultrasonic head wave positioning method in the second embodiment of the present invention;

[0086] Figure 7 This is a flow chart of an ultrasonic head wave positioning method in Embodiment 3 of the present invention;

[0087] Figure 8 It is a schematic diagram of a method for determining a first first wave threshold ratio and a second first wave threshold ratio of a transducer in an ultrasonic first wave positioning method in Embodiment 3 of the present invention;

[0088] Fig. 9 This is a characteristic diagram of the first wave threshold ratio of an ultrasonic first wave positioning method in Embodiment 3 of the present invention;

[0089] Fig.10 are the amplitude characteristic curves of three pairs of transducers at different temperatures;

[0090] Fig.11 is the second wave threshold ratio R F Temperature variation diagram;

[0091] Fig.12 This is a flow chart of an ultrasonic head wave positioning method in Embodiment 4 of the present invention;

[0092] Fig.13 This is a flow chart of an ultrasonic head wave positioning method in Embodiment 5 of the present invention;

[0093] Fig.14 This is a principle block diagram of an ultrasonic head wave positioning device in Embodiment 6 of the present invention;

[0094] Fig.15 This is a functional block diagram of a threshold prediction unit in Embodiment 6 of the present invention. DETAILED DESCRIPTION

[0095] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0096] In order to fully understand the present invention, a detailed description will be provided in the following description. Obviously, the implementation of the embodiments of the present invention is not limited to the specific details familiar to those skilled in the art. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other embodiments.

[0097] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of the features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0098] Ordinal numbers such as "first" and "second" cited in the present invention are merely identifications and do not have any other meanings, such as a specific order, etc. Moreover, for example, the term "first component" itself does not imply the existence of the "second component", and the term "second component" itself does not imply the existence of the "first component".

[0099] It should be noted that the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside" and similar expressions used in this document are for illustrative purposes only and are not limiting.

[0100] Now, exemplary embodiments according to the present invention will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art.

[0101] Embodiment 1

[0102] Figure 1 This is a flow chart of an ultrasonic first wave positioning method provided in Embodiment 1 of the present invention. This embodiment is applicable to detecting the occurrence of wrong waves and accurately positioning the first wave, and specifically includes the following steps:

[0103] S110 determines a first wave threshold ratio of the transducer;

[0104] The first wave threshold ratio is determined according to the characteristics of the transducer, and specifically includes calculation based on the first wave threshold and the first wave amplitude or the first wave threshold and the maximum amplitude of the transducer under a zero flow state.

[0105] S120 selects the initial value of the first wave threshold;

[0106] S130 measures amplitude, including maximum amplitude and first wave amplitude;

[0107] S140 updates the first wave threshold.

[0108] Embodiment 2

[0109] Figure 2 This is a flow chart of an ultrasonic first wave positioning method provided in Embodiment 2 of the present invention. This embodiment is applicable to detecting the occurrence of wrong waves and accurately positioning the first wave, and specifically includes the following steps:

[0110] S210 determines a first wave threshold ratio of the transducer.

[0111] Figure 3 The figure shows the first wave threshold ratio R of the transducer. M The methods include:

[0112] S211 obtains an initialization value, which is determined according to the transducer characteristic curve under zero flow state, wherein the initialization value includes the first wave amplitude A F , first wave number and maximum amplitude A Max0 ;

[0113] Specific measurement methods include Figure 4This figure is also called the amplitude envelope change law diagram. Under zero flow, the transmitting transducer transmits a series of pulse sequences, and the echo signal received by the receiving transducer gradually increases from 0, and gradually reaches the maximum amplitude after several cycles. Generally, the echo signal with a faster amplitude rise speed is selected as the first wave, that is, the horizontal axis corresponding to the point with a larger slope is the first wave number, such as No. 3 in this embodiment is the first wave number, and the corresponding vertical axis is the first wave amplitude A F .

[0114] Maximum Amplitude Max0 is the ordinate corresponding to the maximum peak value of all echoes or the point where the envelope slope is 0 or the ordinate corresponding to the point where the envelope amplitude is the largest. In this embodiment, the maximum amplitude A Max0 is the ordinate corresponding to the point shown in the figure, specifically the ordinate A corresponding to wave 6 Max0 .

[0115] S212 calculates the first wave threshold V F , the first wave threshold V F A is the amplitude of the first wave F and the average of the amplitude of the wave before the first wave number;

[0116] First wave threshold V F A is the amplitude of the first wave F and the average of the amplitude of the wave before the first wave sequence number. In this embodiment, the first wave threshold V F A is the amplitude of wave 3 F The average of the amplitudes of wave 2.

[0117] S213 determines the first first wave threshold ratio R M The specific calculation method is

[0118]

[0119] Because the envelope or rising rate of the echo signal amplitude is determined by the frequency characteristics of the transducer and the excitation signal, and has nothing to do with the signal strength. That is to say, when the maximum amplitude suddenly decreases, the first wave amplitude will also decrease in proportion, and this proportion remains unchanged. Therefore, in the present invention, the first first wave threshold ratio R is defined as M is the ratio of the first wave threshold to the maximum amplitude, that is,

[0120]

[0121] R M It depends on the actual selected first wave sequence number and transducer characteristics. Once determined, the first wave threshold ratio is relatively stable. The first wave threshold ratio R MIt may fluctuate slowly due to changes in temperature, medium type, and sound wave scattering / diffraction characteristics, but the fluctuation range is relatively small. When a wrong wave occurs, it will suddenly increase or decrease. If the signal suddenly weakens and a wrong wave occurs, such as Figure 5 As shown, the first wave threshold ratio R M It will increase significantly and exceed the normal floating range.

[0122] S220 selects the initial value V of the first wave threshold F0 ;

[0123] Figure 6 The figure is a schematic diagram of the principle of first wave positioning. The figure shows two echo signal waveforms that may be encountered in actual measurement. The reasons for this situation may include: changes in the measured medium, superposition of interference signals, changes in flow rate and air pressure, etc. The phases and amplitudes of the two echo signals are different and superimposed with certain noise. Because the initial echo signal is weak and cannot be detected, it is assumed that the third wave peak with appropriate amplitude is selected as the first wave, and the third rising edge zero crossing point after the first wave is taken as the first measured zero crossing point. The propagation time of multiple zero crossing points can be measured continuously. As long as the third wave peak can be accurately found, the time difference can be measured correctly. However, the third wave peak of the first echo signal is close to the second wave peak amplitude of the second echo signal, and the noise interference is superimposed. If the same first wave threshold is used, it is easy to miss the wave.

[0124] Therefore, in actual measurement, it is necessary to first select an initial value V of the first wave threshold F0 However, this initial value may not be able to accurately locate the first wave. It is necessary to promptly discover the wrong wave in the subsequent measurement process and adjust the corresponding first wave threshold as soon as possible.

[0125] S230 measures the maximum amplitude, and measures the maximum amplitude A through the amplitude measurement circuit Max ;

[0126] In the actual measurement process, the time window method is used to measure the maximum amplitude A within a specific time period. Max , this maximum value is a dynamically changing value in different time periods.

[0127] Although the first wave may not be located, the maximum amplitude A Max It is not affected by the first wave positioning error.

[0128] S240 Update the first wave threshold V F1 , according to the measured maximum amplitude A Max R M Calculate the first wave threshold V F1 .

[0129] S230 will measure the maximum amplitude A MaxSent to S240, S240 receives the maximum dynamic amplitude A Max R M Calculate the first wave threshold V F1 The specific calculation formula is V F1 =R M *A Max , and the calculated V F1 Replace V F0 , update the first wave threshold.

[0130] In this embodiment, the first wave threshold ratio R M , is the first wave threshold ratio R of the transducer measured under the condition of stable static amplitude or zero flow M , if it needs to be used at different temperatures, the average value within the temperature used should be taken.

[0131] Embodiment 3

[0132] Figure 7 This is a flow chart of an ultrasonic head wave positioning method in Embodiment 3 of the present invention, which specifically includes:

[0133] S310 determines the first wave threshold ratio R of the transducer M and the second first wave threshold ratio R F , set R F Error range R F-min ~R F-max ;

[0134] like Figure 8 As shown, the first wave threshold ratio R of the transducer is determined M and the second wave threshold ratio R F The methods specifically include:

[0135] S311 obtains an initialization value, which is determined according to the transducer characteristic curve under zero flow state, wherein the initialization value includes the first wave amplitude A F , first wave number and maximum amplitude A M ax0;

[0136] S312 calculates the first wave threshold V F , the first wave threshold V F A is the amplitude of the first wave F and the average of the amplitude of the wave before the first wave number;

[0137] S313 determines the first first wave threshold ratio R M The specific calculation method is

[0138]

[0139] S314 determines the second first wave threshold ratio R F The specific calculation method is

[0140] .

[0142] Determine the second first wave threshold ratio R according to actual needs and experience F The error range R F-min ~R F-max In this embodiment, ±10% can be selected, and any available error range can also be selected according to other national standards, such as the actual R F Beyond R F-min ~R F-max range, it can be considered that a wrong wave occurs.

[0143] In the present invention, the first wave refers to the designated nth echo signal that is easy to detect, and the peak value of the first wave is the first wave amplitude A F , the maximum peak value of all echoes is the maximum amplitude A Max The threshold level used to detect the first wave is called the first wave threshold V F .like Figure 4 As shown in the figure, the echo signal with a faster amplitude rise speed is generally selected as the first wave, and the first wave threshold is close to the average of the first wave amplitude and the waveform amplitude before the first wave. In this scheme, the first wave threshold is the average of the first wave amplitude and the waveform amplitude before the first wave. At the same time, two first wave threshold ratios are defined, namely, the first wave threshold ratio R M and the second first wave threshold ratio R F , R M is the ratio of the first wave threshold to the maximum amplitude, R F It is the ratio of the first wave threshold to the first wave amplitude. Generally, R M Less than R F , R F is between 0.5 and 0.9, preferably 0.7, which depends on the actual selected first wave sequence number and transducer characteristics. Once determined, the two first wave threshold ratios are relatively stable, such as Fig. 9 As shown, the first wave threshold ratio R M and the second first wave threshold ratio R F It may fluctuate slowly due to changes in temperature, medium type, and sound wave scattering / diffraction characteristics, but the fluctuation range is relatively small. Fig.10 These are the amplitude characteristic curves of the three pairs of transducers at different temperatures. Due to the inconsistency between the two transducers, the received amplitudes may be different. It can be seen that the amplitudes of different echoes will vary to a certain extent with temperature. Fig.11 is the second wave threshold ratio R FThe temperature variation diagram, specifically the ratio of the amplitude of the first wave to the amplitude of the first to fifth waves, shows that although the amplitudes vary, the ratio is relatively stable. The ratio of the first wave to the first wave is 1, and the ratio of the first wave to the second wave is around 0.5. If the second wave is selected as the first wave, then R F The average amplitude of these two waves is 0.75. Of course, if the other echo is taken as the first wave, then R F The value will be adjusted accordingly. When an error wave occurs, it will suddenly increase or decrease. Figure 5 If the signal suddenly weakens and the wave is wrong, the first wave threshold ratio will increase significantly and exceed the normal floating range. According to the principle of constant first wave threshold ratio, the correct first wave threshold can be obtained according to the new amplitude and first wave threshold ratio. If it needs to be used at different temperatures, the average value within the temperature should be taken.

[0144] S320 selects the initial value V of the first wave threshold F0 ;

[0145] According to the normal working state of the transducer, the initial value V of the first wave threshold is selected. F0 , this initial value may not be able to accurately locate the first wave. Therefore, it is necessary to find the wrong wave in time in the subsequent steps and correct the value of the first wave threshold.

[0146] S330 measures the amplitude and measures the first wave amplitude A through the amplitude measurement circuit F and maximum amplitude A Max ;

[0147] In the actual measurement process, Figure 4 or Figure 6 As shown, according to the selected initial value V of the first wave threshold F0 , measure the first wave amplitude A through the amplitude measurement circuit F and maximum amplitude A Max .

[0148] S340 determines the quality of the first wave threshold. If

[0149]

[0150] , then the first wave threshold V′ F =R F *A F ;like

[0151]

[0152] or

[0153]

[0154] , then the first wave threshold V' F =RM *A Max ;

[0155] S350 updates the first wave threshold.

[0156] Embodiment 4

[0157] Fig.12 This is a flow chart of an ultrasonic head wave positioning method in Embodiment 4 of the present invention, which specifically includes:

[0158] S410 determines the first wave threshold ratio R of the transducer M and the second first wave threshold ratio R F , set R M Error range R M-min ~R M-max , set R F Error range R F-min ~R F-max ;

[0159] The first wave threshold ratio R of the transducer is determined M and the second wave threshold ratio R F The method is similar to that of the third embodiment, and the method of the third embodiment may be referred to, which will not be described in detail here.

[0160] Determine the first wave threshold ratio R according to actual needs and experience M The error range R M-min ~R M-max and the second first wave threshold ratio R F The error range R F-min ~R F-max In this embodiment, ±10% can be selected, R M-min ~R M-max With R F-min ~R F-max The ranges can be the same or different, depending on actual needs. You can also choose any available error range according to other national standards, such as the actual R F Beyond R F-min ~R F-max range, it can be considered that a wrong wave occurs.

[0161] S420 selects the initial value V of the first wave threshold F0 ;

[0162] S430 measures the amplitude and measures the first wave amplitude A through the amplitude measurement circuit F and maximum amplitude A Max ;

[0163] S440 determines the quality of the first wave threshold. If

[0164]

[0165] , then the first wave threshold V′ F =R F *A F ;like

[0166]

[0167] or

[0168]

[0169] , then the first wave threshold V' F =R M *A Max ;

[0170] S450 updates the first wave threshold;

[0171] S460 updates the first wave threshold ratio R M ,like

[0172]

[0173] and

[0174] ,

[0175] but

[0176] ;

[0178] Update the first wave threshold ratio.

[0179] Under working conditions, as environmental conditions change, R F The change range relative to R M To be milder or smaller, therefore, by limiting R F The error range of R F The value updates the first wave threshold with higher reliability. M It is also limited within a reasonable range, which can serve as a double insurance and can restore the authenticity of the results and data to the greatest extent.

[0180] Embodiment 5

[0181] Fig.13 This is a flow chart of an ultrasonic head wave positioning method in Embodiment 5 of the present invention, which specifically includes:

[0182] S510 determines the first wave threshold ratio R of the transducer M and the second first wave threshold ratio R F , set R M Error range R M-min ~RM-max , set R F Error range R F-min ~R F-max ;

[0183] The first wave threshold ratio R of the transducer is determined M and the second wave threshold ratio R F The method is similar to that of the fourth embodiment, and can be referred to the method of the fourth embodiment, which will not be described in detail here.

[0184] S520 selects the initial value V of the first wave threshold F0 ;

[0185] S530 measures the amplitude and measures the first wave amplitude A through the amplitude measurement circuit F and maximum amplitude A Max ;

[0186] S540 updates the first wave threshold ratio R M ,like

[0187]

[0188] and

[0189]

[0190] , then the first wave threshold ratio is updated to

[0191] ;

[0193] S550 updates the first wave threshold, V' F =R' M *A Max ;

[0194] Embodiment 6

[0195] Fig.14 This is a principle block diagram of an ultrasonic first wave positioning device in Example 6 of the present invention, including a transducer, a signal conditioning unit, a first wave threshold unit, a comparator, a timing unit, an amplitude measurement unit, a post-processing unit and a threshold prediction unit; the transducer is used to receive an ultrasonic echo signal and send it to the signal conditioning unit; the signal conditioning unit is used to perform noise reduction and scaling processing on the ultrasonic echo signal and send it to the comparator; the first wave threshold unit is used to receive and store a variable threshold and send it to the comparator; the comparator compares the data sent by the signal conditioning unit and the first wave threshold unit, and outputs a signal with a waveform higher than the first wave threshold to the timing unit, returns the first wave threshold to a zero reference voltage, and performs zero crossing detection; the timing unit records the zero crossing time and sends it to the post-processing unit

[0196] The processing unit analyzes; the amplitude measurement unit is used to measure the first wave amplitude and the maximum amplitude; the threshold prediction unit calculates and predicts the next first wave threshold according to the data measured by the amplitude measurement unit, and feeds the predicted first wave threshold back to the first wave threshold unit.

[0197] The ultrasonic pulse arrives at the receiving transducer and is converted into an electrical signal. After being filtered and amplified by the signal conditioning unit, it is sent to the comparator and compared with the variable threshold voltage generated by the first wave threshold unit. When the waveform is higher than the threshold level, a signal is output and the threshold level is automatically returned to the zero reference voltage for zero-crossing detection. The time of the zero-crossing moment is recorded by the timing unit and then submitted to the post-processing unit for analysis.

[0198] In addition to the conventional ultrasonic time measurement circuit, this scheme adds an amplitude measurement unit and a threshold prediction unit. The former is responsible for measuring the amplitude voltage and maximum amplitude voltage of the echo received with a specified sequence number, and the latter predicts the next first wave threshold based on the amplitude voltage, such as Fig.15 As shown, the threshold prediction unit includes a first first wave threshold ratio register and a second first wave threshold ratio register, wherein the first first wave threshold ratio register and the second first wave threshold ratio register receive the maximum amplitude, the first wave amplitude and the latest first wave threshold sent by the amplitude measurement unit and the post-processing unit, and send the next first wave threshold. The threshold prediction can be implemented by software logic or by hardware circuit. If the measurement circuit includes multiple transducers, multiple threshold prediction units can be equipped to control each of them independently.

[0199] Embodiment 7

[0200] Embodiment 7 of the present invention further provides an electronic device, comprising: one or more processors; a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement an ultrasonic first wave positioning method described in any one of the above embodiments.

[0201] Through the above description of the implementation mode, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course it can also be implemented by hardware, but in many cases the former is a better implementation mode. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of various embodiments of the present invention.

[0202] It is worth noting that in the above-mentioned embodiment of the ultrasonic head wave positioning system, the various units and modules included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0203] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An ultrasonic head wave positioning method, characterized in that: include: determining a first wave threshold ratio of the transducer; Select the initial value of the first wave threshold; Measure amplitude, including maximum amplitude and first wave amplitude; Update the first wave threshold.

2. The ultrasonic head wave positioning method according to claim 1, characterized in that: It also includes judging the quality of the first wave threshold.

3. The ultrasonic head wave positioning method according to claim 2, characterized in that: It also includes updating the first wave threshold ratio.

4. The ultrasonic head wave positioning method according to claim 1, characterized in that: The first wave threshold ratio is determined according to the characteristics of the transducer, and specifically includes calculation based on the first wave threshold and the first wave amplitude or the first wave threshold and the maximum amplitude of the transducer under a zero flow state.

5. The ultrasonic head wave positioning method according to claim 1, characterized in that: Specifically include: Determine the first wave threshold ratio R of the transducer M ; Select the initial value V of the first wave threshold F0 ; Measure the amplitude and measure the maximum amplitude A through the amplitude measurement circuit Max ; Update the first wave threshold V' F , according to the measured maximum amplitude A Max R M Calculate the first wave threshold V' F .

6. The ultrasonic head wave positioning method according to claim 5, characterized in that: The first wave threshold V' F =R M *A Max .

7. The ultrasonic head wave positioning method according to claim 6, characterized in that: The first wave threshold ratio R of the transducer is determined M The methods specifically include: Obtain an initialization value, which is determined according to the transducer characteristic curve under zero flow state, wherein the initialization value includes the first wave amplitude A F , first wave number and maximum amplitude A Max0 ; Calculate the first wave threshold V F , the first wave threshold V F A is the amplitude of the first wave F and the average of the amplitude of the wave before the first wave number; Determine the first wave threshold ratio R M The specific calculation method is 8. The ultrasonic head wave positioning method according to claim 2, characterized in that: Specifically include: Determine the first wave threshold ratio R of the transducer M and the second first wave threshold ratio R F , set R F Error range R F-min ~R F-max ; Select the initial value V of the first wave threshold F0 ; Measure the amplitude, measure the first wave amplitude A through the amplitude measurement circuit F and maximum amplitude A Max ; To judge the quality of the first wave threshold, if ， Then the first wave threshold V′ F =R F *A F ;like or ， Then the first wave threshold V' F =R M *A Max ; Update the first wave threshold.

9. The ultrasonic head wave positioning method according to claim 8, characterized in that: The first wave threshold ratio R of the transducer is determined M and the second wave threshold ratio R F The methods specifically include: Obtain an initialization value, which is determined according to the transducer characteristic curve under zero flow state, wherein the initialization value includes the first wave amplitude A F , first wave number and maximum amplitude A Max0 ; Calculate the first wave threshold V F , the first wave threshold V F A is the amplitude of the first wave F and the average of the amplitude of the wave before the first wave number; Determine the first wave threshold ratio R M The specific calculation method is Determine the second first wave threshold ratio R F The specific calculation method is 10. The ultrasonic head wave positioning method according to claim 3, characterized in that: Specifically include: Determine the first wave threshold ratio R of the transducer M and the second first wave threshold ratio R F , set R M Error range R M-min ~R M-max , set R F Error range R F-min ~R F-max ; Select the initial value V of the first wave threshold F0 ; Measure the amplitude, measure the first wave amplitude A through the amplitude measurement circuit F and maximum amplitude A Max ; To judge the quality of the first wave threshold, if ， Then the first wave threshold V′ F =R F *A F ;like or ， Then the first wave threshold V' F =R M *A Max ; Update the first wave threshold; Update the first wave threshold ratio R M ,like and ， Then the first wave threshold ratio is updated to 11. The ultrasonic head wave positioning method according to claim 10, characterized in that: The first wave threshold ratio R of the transducer is determined M and the second first wave threshold ratio R F The methods specifically include: Obtain an initialization value, which is determined according to the transducer characteristic curve under zero flow state, wherein the initialization value includes the first wave amplitude A F , first wave number and maximum amplitude A Max0 ; Calculate the first wave threshold V F , the first wave threshold V F A is the amplitude of the first wave F and the average of the amplitude of the wave before the first wave number; Determine the first wave threshold ratio R M The specific calculation method is Determine the second first wave threshold ratio R F The specific calculation method is 12. An ultrasonic head wave positioning method according to any one of claims 5, 6, 7, 8, 9, 10, and 11, characterized in that: The first first wave threshold ratio R M Or the second first wave threshold ratio R F It is the average value under different operating temperatures.

13. The ultrasonic head wave positioning method according to claim 12, characterized in that: The R F The range is 0.5~0.

9.

14. The ultrasonic head wave positioning method according to claim 13, characterized in that: The R F Preferred is 0.

7.

15. An ultrasonic head wave positioning device, characterized in that: It includes a transducer, a signal conditioning unit, a first wave threshold unit, a comparator, a timing unit, an amplitude measurement unit, a post-processing unit and a threshold prediction unit; the transducer is used to receive an ultrasonic echo signal and send it to the signal conditioning unit; the signal conditioning unit is used to perform noise reduction and scaling processing on the ultrasonic echo signal and send it to the comparator; the first wave threshold unit is used to receive and store a variable threshold and send it to the comparator; the comparator compares the data sent by the signal conditioning unit and the first wave threshold unit, and outputs a signal with a waveform higher than the first wave threshold to the timing unit, returns the first wave threshold to a zero reference voltage, and performs zero-crossing detection; the timing unit records the zero-crossing time and sends it to the post-processing unit for analysis; the amplitude measurement unit is used to measure the first wave amplitude and the maximum amplitude; the threshold prediction unit calculates and predicts the next first wave threshold based on the data measured by the amplitude measurement unit, and feeds the predicted first wave threshold back to the first wave threshold unit.

16. The ultrasonic head wave positioning device according to claim 15, characterized in that: The threshold prediction unit includes a first first-wave threshold ratio register and a second first-wave threshold ratio register, which receive the maximum amplitude, the first-wave amplitude and the latest first-wave threshold sent by the amplitude measurement unit and the post-processing unit, and send the next first-wave threshold.

17. An electronic device, characterized in that: The device comprises: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement an ultrasonic head wave positioning method as described in any one of claims 1 to 14.

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