Ultrasonic echo first wave arrival time calculation method, system and storage medium

Abstract

The present application relates to the technical field of well logging technology, and in particular to a method, system, and storage medium for calculating the arrival time of the first wave of an ultrasonic echo. The method comprises obtaining a time-domain original signal of an ultrasonic waveform in real time within a sampling period; obtaining a preset time window length and time window step, and obtaining corresponding search starting point information; calculating the time-domain original signal of the ultrasonic waveform based on the time window length, search starting point information, and time window step to obtain a corresponding energy product characteristic curve; obtaining the maximum value of the energy product characteristic curve; and obtaining the arrival time information of the first wave of the echo based on the time information corresponding to the maximum value of the energy product characteristic curve. The present application has the effect of improving the accuracy of extracting the arrival time of the first wave of an ultrasonic echo.

Description

Technical Field

[0001] The present application relates to the technical field of well logging technology, and in particular to a method, system and storage medium for calculating the arrival time of the first wave of an ultrasonic echo. Background Art

[0002] Borehole geometry information is one of the necessary engineering information for logging while drilling or post-drilling wireline logging. Borehole dimension information can also be used as an important input parameter for data correction of other types of logging instruments, such as resistivity measuring instruments and radioactivity measuring instruments.

[0003] The measurement of wellbore geometry is mainly based on the principle of ultrasonic pulse reflection ranging. Ultrasonic transceivers, such as ultrasonic transducers, are used to transmit pulsed acoustic signals of a certain frequency into the wellbore. At the same time, they can also receive the time-domain signals of reflected echoes from the wellbore wall. Based on the energy characteristics of the received reflected echo time-domain signals, the arrival time of the first echo wave is extracted. The first wave is characterized by the first received reflected acoustic wave signal. Combined with the speed of sound in the mud, the distance from the ultrasonic transceiver to the wellbore wall can be obtained. This distance can reflect the wellbore geometry.

[0004] In the related art, for the reflected echo time domain signal, the commonly used processing method is the energy method or the energy ratio method to identify the echo head wave. However, the conventional processing method may cause recognition errors due to noise signal interference and other situations, and the accuracy of identifying the echo head wave is low. Summary of the Invention

[0005] In order to improve the extraction accuracy of ultrasonic echo first wave arrival time, the present application provides an ultrasonic echo first wave arrival time calculation method, system and storage medium.

[0006] In the first aspect, the present application provides a method for calculating the arrival time of the first wave of an ultrasonic echo, which adopts the following technical solution:

[0007] A method for calculating the arrival time of the first wave of an ultrasonic echo comprises the following steps:

[0008] Acquire the original time domain signal of the ultrasonic waveform in real time within the sampling period;

[0009] Obtain the preset time window length and time window step, and obtain the corresponding search starting point information;

[0010] Calculating the ultrasonic waveform time domain original signal according to the time window length, the search starting point information and the time window step to obtain a corresponding energy product characteristic curve;

[0011] Obtaining a maximum value of the energy product characteristic curve;

[0012] According to the time information corresponding to the maximum value of the energy product characteristic curve, the echo first wave arrival time information is obtained

[0013] In some embodiments, acquiring the ultrasonic waveform time domain original signal in real time during the acquisition period further includes:

[0014] Get the current depth information to obtain the corresponding depth label;

[0015] The original ultrasonic waveform time domain signals corresponding to different depth labels are obtained according to the preset depth intervals.

[0016] In some embodiments, after collecting the original time domain signals of the ultrasonic waveforms corresponding to the different depth tags, the method further includes:

[0017] The original time-domain information of the ultrasonic waveform is normalized and preprocessed.

[0018] In some embodiments, calculating the ultrasonic waveform time domain original signal according to the time window length, the search starting point information, and the time window step to obtain a corresponding energy product characteristic curve includes:

[0019] Obtain the depth label corresponding to the initial depth according to the preset depth selection rule;

[0020] Based on the original time domain signal of the ultrasonic waveform corresponding to the depth tag, the time window energy product sub-eigenvalue is obtained according to the time window energy product algorithm. The time window energy product algorithm is: Among them, C i It is represented by the time window energy product eigenvalue, the operator ".*" represents the multiplication of the corresponding positions of two arrays of the same dimension, Ts represents the search start time, Twin represents the time window length, and Wave represents the original signal of the ultrasonic waveform in the time domain;

[0021] Moving the time window position according to the time window step size to obtain a plurality of time window energy product sub-eigenvalues ​​within a sampling period;

[0022] An energy product characteristic curve is obtained according to several time window energy product sub-eigenvalues.

[0023] In some embodiments, obtaining corresponding search starting point information includes:

[0024] Obtaining the initial point of the sampling period and defining it as the starting reference point, wherein the initial point of the sampling period is characterized as the time point at which the sampling begins;

[0025] Obtain a sampling period time point after a preset time interval from the starting reference point and define it as an intermediate reference point;

[0026] Obtaining the ultrasonic waveform time domain original signals corresponding to the starting reference point and the intermediate reference point, and determining whether the difference between the ultrasonic waveform time domain original signals corresponding to the two points is greater than a threshold;

[0027] If it is greater, the current intermediate reference point is defined as the new initial reference point, and a new intermediate reference point is obtained according to the preset time interval, and the subsequent steps are repeated;

[0028] If it is less than, the current intermediate reference point is defined as the search starting point information.

[0029] In some embodiments, after obtaining the echo first wave arrival information, the method further includes:

[0030] Obtaining a plurality of echo first wave arrival information according to different depth labels, and obtaining an echo first wave arrival curve according to the plurality of echo first wave arrival information;

[0031] Acquire corresponding waveform time domain graphs according to the ultrasonic waveform time domain original signals corresponding to different depth labels;

[0032] Substituting the echo first wave arrival time curve into the waveform time domain diagram;

[0033] Determine whether the overlap between the echo first wave arrival curve and the first wave signals on the plurality of ultrasonic waveform time domain original signals in the waveform time domain diagram is greater than a preset overlap value;

[0034] If it is greater than, it is determined that the arrival time information of the first echo wave is valid;

[0035] If it is less than, it is determined that the echo first wave arrival time information is invalid.

[0036] In a second aspect, the present application provides an ultrasonic echo first wave arrival time calculation system, which adopts the following technical solution: an ultrasonic echo first wave arrival time calculation system, comprising an ultrasonic transducer and a processor, wherein:

[0037] The ultrasonic transducer is used to transmit a pulsed sound wave signal and receive the reflected ultrasonic waveform time domain original signal;

[0038] The processor is used to obtain the ultrasonic waveform time domain original signal in real time within a sampling period, obtain a preset time window length and time window step, and obtain corresponding search starting point information, calculate the ultrasonic waveform time domain original signal according to the time window length, search starting point information and time window step to obtain a corresponding energy product characteristic curve, obtain the maximum value of the energy product curve, and obtain the echo first wave arrival time information according to the time information corresponding to the maximum value of the energy product characteristic curve.

[0039] In a third aspect, the present application provides an ultrasonic echo first wave arrival time calculation system, which adopts the following technical solution: a computer storage medium on which a computer program is stored, and when the computer program is executed by a processor, the above-mentioned ultrasonic echo first wave arrival time calculation method is implemented.

[0040] In summary, this application has the following beneficial technical effects:

[0041] Without changing the existing instrument hardware circuit and mechanical structure, the uncertainty and external influence of the echo first wave arrival time calculation are eliminated by using the energy product algorithm only through the collected ultrasonic waveform time domain original signal, and the ultrasonic echo first wave arrival time information can be accurately extracted. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the overall process of the embodiment of the present application;

[0043] Figure 2 This is a schematic diagram of a specific process for calculating the original signal of the ultrasonic waveform in the time domain and obtaining the energy product characteristic curve according to the time window length, the search starting point position and the time window step in the embodiment of the present application;

[0044] Figure 3 Schematic diagram of the original time domain signal of the ultrasonic waveform obtained in the embodiment of the present application;

[0045] Figure 4 Schematic diagram of the energy product characteristic curve in the embodiment of the present application;

[0046] Figure 5 It is a schematic diagram comparing the echo first wave arrival time curve and the ultrasonic waveform time domain original signal in the waveform time domain diagram in the embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. However, it should be understood by those skilled in the art that the present application can be implemented without these details. In some cases, in order to avoid unnecessary descriptions that make various aspects of the present application obscure, the well-known methods, processes, systems, components and / or circuits that have been described at a higher level will not be described in detail. It is obvious to those skilled in the art that various changes can be made to the embodiments disclosed in the present application, and the general principles defined in the present application can be applied to other embodiments and application scenarios without departing from the principles and scope of the present application. Therefore, the present application is not limited to the embodiments shown, but conforms to the broadest scope consistent with the scope claimed for protection in the present application.

[0048] Unless otherwise defined, the technical terms or scientific terms involved in this application should have the general meaning understood by people with ordinary skills in the technical field to which this application belongs. The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. Words such as "one", "a", "the", "these" and the like used in this application do not represent quantitative restrictions, and they can be singular or plural. The terms "comprise", "include", "have" and any variants thereof involved in this application are intended to cover non-exclusive inclusions; for example, a process, method and system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent to these processes, methods, products or devices.

[0049] As used in this application, "plurality" refers to two or more. Typically, the character " / " indicates an "or" relationship between related objects. Terms such as "first," "second," and "third" used in this application simply distinguish between similar objects and do not represent a specific ordering of the objects.

[0050] The terms "system", "engine", "unit", "module" and / or "block" involved in this application are a method for distinguishing different components, elements, parts, components, assemblies, or functions at different levels by level. These terms can be replaced by other expressions that can achieve the same purpose. Generally, the "module", "unit" or "block" involved in this application refers to a collection of logic or software instructions embodied in hardware or firmware. The "module", "unit" or "block" described in this application can be implemented as software and / or hardware, and in the case of being implemented as software, they can be stored in any type of non-volatile computer-readable storage medium or storage device.

[0051] In some embodiments, software modules / units / blocks can be compiled and linked into an executable program. It will be appreciated that a software module can be callable from other modules / units / blocks or from itself, and / or can be called in response to a detected event or interrupt. Software modules / units / blocks configured to be executed on a computing device can be provided on a computer-readable storage medium, such as an optical disc, digital video disc, flash drive, magnetic disk, or any other tangible medium, or as a digital download (and can be initially stored in a compressed or installable format that requires installation, decompression, or decryption prior to execution). Such software code can be stored in part or in whole on a storage device of the executing computing device and applied to the operation of the computing device. Software instructions can be embedded in firmware, such as an EPROM. It will also be appreciated that hardware modules / units / blocks can be included in connected logic components, such as gates and flip-flops, and / or can be included in programmable units, such as programmable gate arrays or processors. The modules / units / blocks or computing device functions described herein can be implemented as software modules / units / blocks, and can also be represented in hardware or firmware. Generally, the modules / units / blocks described herein may be combined with other modules / units / blocks, or may be divided into sub-modules / sub-units / sub-blocks, despite their physical organization or storage. The description may apply to a system, an engine, or a portion thereof.

[0052] It will be understood that when a unit, engine, module, or block is referred to as being "on," "connected," or "coupled to" another unit, engine, module, or block, it can be directly on, connected, coupled, or in communication with the other unit, engine, module, or block, or there can be intervening units, engines, modules, or blocks, unless the context clearly indicates otherwise. In this application, the term "and / or" may include any one or more of the relevant listed items or any combination thereof.

[0053] The following is combined with Figure 1-5 This application is described in further detail.

[0054] The embodiment of the present application discloses a method for calculating the arrival time of the first wave of an ultrasonic echo.

[0055] like Figure 1 As shown, a method for calculating the arrival time of the first wave of an ultrasonic echo includes the following steps:

[0056] S100, obtaining the original ultrasonic waveform time domain signal in real time within a sampling period.

[0057] The acquisition period is pre-set. Because the propagation speed of sound waves is 340 meters per second, the acquisition period can be set shorter, typically 120 to 150 microseconds. The ultrasonic waveform time domain raw signal refers to the reflected sound wave signal received after the ultrasonic transducer transmits the pulse sound wave signal and then reflects it.

[0058] Specifically, it also includes:

[0059] S110, obtaining the current collected depth information to obtain a corresponding depth label;

[0060] S120 , obtaining ultrasonic waveform time-domain original signals corresponding to different depth labels according to a preset depth interval.

[0061] The ultrasonic transducer collects ultrasonic echo signals in real time during the measurement process along the wellbore, and obtains the original time domain signals of the ultrasonic waveform at different times within the acquisition cycle at different formation depths.

[0062] Each depth corresponds to a depth tag, and each depth tag corresponds to the original ultrasonic waveform time domain signal. The default value of the depth interval can be 0.1 meters.

[0063] After collecting the original time domain information of the ultrasonic waveform corresponding to different depth labels, it also includes:

[0064] S130, performing normalization preprocessing on the original time domain information of the ultrasonic waveform.

[0065] Normalization means that when a data x is centered according to the minimum value and then scaled according to the range (maximum value - minimum value), the final data moves by the minimum value units and will converge to [0, 1] to prevent amplitude overflow in data processing.

[0066] The formula for normalization preprocessing is:

[0067] After normalization, the original data can be converted into dimensionless indicator evaluation values, that is, the values ​​of each indicator are at the same quantitative level, and comprehensive evaluation and analysis can be carried out.

[0068] S200: Obtain a preset time window length and time window step, and obtain corresponding search starting point information.

[0069] A time window is represented as a data analysis window represented by sub-time lengths. Data processing, analysis, and feature extraction are achieved by windowing the data. The time window length refers to the predetermined duration of a time window, such as 1us, 2us, 4us, or 10us, and can be modified based on actual conditions. The time window step size refers to the distance the window is moved in the forward direction of time after the data within the time window is processed and analyzed. For example, if the time window length is 3us and the time window step size is 2us, the time window step size is usually smaller than the time window length. Initially, assuming the starting search time is 20us, the time window will contain data between 20us and 23us. After data processing is complete, the time window will advance by a step size of 2us, and the data within the window will now be between 22us and 25us. After data processing is complete, the time window will advance by another step size of 2us, and the data within the window will now be between 24us and 27us. This process continues for all data within the acquisition period.

[0070] The search starting point information can be obtained by presetting or by following the steps below:

[0071] S210: Acquire the initial point of the acquisition cycle and define it as the initial reference point.

[0072] The acquisition cycle initial point is defined as the time when the acquisition begins. At the beginning of an acquisition cycle, the acquisition cycle initial point is defined as 0us and serves as the initial reference point.

[0073] S220 , obtaining a sampling period time point after a preset time interval from the starting reference point, and defining it as an intermediate reference point.

[0074] The preset time interval can be changed according to actual conditions. Taking 2us as an example, if the initial collection point, that is, 0us, is set back 2us, the time to the middle reference point is 2us.

[0075] S230 , obtaining the ultrasonic waveform time domain original signals corresponding to the starting reference point and the intermediate reference point, and determining whether the difference between the ultrasonic waveform time domain original signals corresponding to the two points is greater than a threshold.

[0076] Obtain the original ultrasonic waveform time domain signals at 0us and 2us, connect the two points to obtain the connecting line of the corresponding ultrasonic waveform time domain original signals, perform difference calculation, and determine whether the difference is greater than the threshold. After the difference is calculated, the difference obtained represents the change amplitude of the ultrasonic waveform time domain original signals at the two points.

[0077] S240: If it is greater than, define the current intermediate reference point as a new initial reference point, obtain a new intermediate reference point according to a preset time interval, and repeat the subsequent steps.

[0078] S250: If it is less than, the current intermediate reference point is defined as the search starting point information.

[0079] When the original ultrasonic waveform time domain signal is collected, multiple waveform fluctuation signals will be received in the received waveform signal, such as Figure 2 As shown in the figure, the first waveform, that is, the signal corresponding to the initial moment of the acquisition cycle, is the ultrasonic pulse emission signal collected at the moment the ultrasonic transducer emits a pulse, and the subsequent ones are the echo first wave, secondary echo and even tertiary echo. What needs to be collected and the arrival time determined is the echo first wave signal, and we need to extract the ultrasonic pulse emission signal to avoid misjudging the pulse emission signal as the echo first wave signal.

[0080] Therefore, the change in amplitude of the ultrasonic waveform time domain raw signal from the initial time of the acquisition cycle and subsequent reference points determines whether a signal has appeared within this time interval. Because the initial reference point is the beginning of the acquisition cycle, the signal collected at this time must be a pulse transmission signal, and its amplitude at this time will be greater than the threshold. At this time, the current intermediate reference point is defined as the new initial reference point, that is, the new initial reference point is 2us. New intermediate reference points are then acquired, and the difference between the ultrasonic waveform time domain raw signals is calculated and compared to determine whether the pulse transmission signal has completely ended within this time interval. If not, the above steps are repeated. If the amplitude of the ultrasonic waveform time domain raw signal at two reference points within a time interval is less than the threshold, it indicates that the pulse transmission signal has ended and the reflected signal has not returned. If the waveform changes subsequently, it can be considered the waveform signal of the first echo wave. At this time, the current intermediate reference point is used as the search starting point information, and the current starting reference point can also be used as the search starting point information.

[0081] For example, if the signal amplitude at 18us-20us is smaller than the preset value, then 20us is used as the search starting point, and the window operation is performed according to the time window length and time window step.

[0082] S300 , calculating the original time domain information of the ultrasonic waveform according to the time window length, the search starting point information and the time window step length to obtain a corresponding energy product characteristic curve.

[0083] like Figure 3 As shown, specifically including:

[0084] S310: Obtain a depth label corresponding to the initial depth according to a preset depth selection rule.

[0085] The depth selection rule can be replaced accordingly according to the specific application scenario. The depth can be acquired from a deeper depth to a shallower depth, in which case the starting depth is the bottom of the well; or the depth can be acquired from a shallower depth to a deeper depth, in which case the starting depth is the shallower depth.

[0086] S320: Based on the original time domain signal of the ultrasonic waveform corresponding to the depth tag, obtain a time window energy product sub-eigenvalue according to a time window energy product algorithm. The time window energy product algorithm is specifically as follows:

[0087] Among them, C i The representation is the time window energy product eigenvalue. The operator ".*" represents the multiplication of corresponding positions of two arrays of the same dimension, and the calculation result is still the coefficient of the same dimension. Ts represents the search start time, Twin represents the time window length, Wave represents the original time domain signal of the ultrasonic waveform, and i = 1, 2, 3, ..., N. The time window range is [Ts, Ts+Twin].

[0088] S330 , moving the time window position according to the time window step size to obtain a number of time window energy product sub-eigenvalues ​​within a sampling period.

[0089] After calculating the time window energy product eigenvalue in a time window, according to the time window step length T step , move the position of the time window to obtain the time window energy product sub-eigenvalues ​​corresponding to several time windows within the acquisition period.

[0090] S340: Obtain an energy product characteristic curve according to a plurality of time window energy sub-characteristic values.

[0091] Establish a coordinate system with the x-axis as the acquisition time and the y-axis as the eigenvalue size. Substitute several time window energy sub-eigenvalues ​​into the coordinate system in combination with their corresponding times, and connect each sub-eigenvalue to obtain the energy product characteristic curve.

[0092] S400: Obtaining the maximum value of the energy product characteristic curve.

[0093] S500 , obtaining the arrival time information of the first echo wave according to the time information corresponding to the maximum value of the energy product characteristic curve.

[0094] Search for the maximum value in the energy product characteristic curve, and its corresponding acquisition time is the arrival time of the first wave of the ultrasonic echo T head .

[0095] The time window energy product algorithm can effectively eliminate the uncertainty of the echo first wave arrival time calculation and accurately extract the ultrasonic echo first wave arrival time information.

[0096] like Figure 4 As shown, the energy product characteristic curve has multiple fluctuations, which are the first echo wave, the second echo and even the third echo. The maximum value of the energy product characteristic curve corresponds to the arrival time of the first echo wave signal.

[0097] It should be noted that when obtaining the echo first wave arrival time information based on the maximum value of the energy product characteristic curve, the time discarded when selecting the energy product characteristic curve in the previous step needs to be taken into account to avoid calculating the wrong time.

[0098] After obtaining the first echo wave, the following steps are also included:

[0099] S600: Obtain a plurality of first wave echo arrival information according to different depth tags, and obtain an echo first wave arrival time curve according to the plurality of first wave echo arrival information.

[0100] Connect each depth label, that is, the first wave echo arrival time information obtained by calculation at each depth, to obtain the echo first wave arrival time curve

[0101] S610 , obtaining corresponding waveform time domain graphs according to original ultrasonic waveform time domain information corresponding to different depth labels.

[0102] S620: Substitute the echo first wave arrival time curve into the waveform time domain diagram.

[0103] The waveform time domain diagram is a waveform time domain representation diagram with the x-axis being the acquisition time and the y-axis being the time.

[0104] S630, determine whether the degree of overlap between the echo first wave arrival curve and the first wave signals on several ultrasonic waveform time domain original signals in the waveform time domain diagram is greater than a preset overlap value. If it is greater than, the echo first wave arrival information is determined to be valid; if it is less than, the echo first wave arrival information is determined to be invalid.

[0105] Substitute the echo first wave arrival time curve into the waveform time domain diagram. Since all elements in the echo first wave arrival time curve are time, when the echo first wave arrival time curve is substituted into the waveform time domain diagram, it is displayed as a curve extending along the y-axis direction.

[0106] We need to compare whether the echo first wave signal at each depth coincides with the starting point of the first wave arrival signal in the waveform time domain diagram of the relative depth. Because the ultrasonic waveform time domain original signal in the waveform time domain diagram can show the specific waveform fluctuations, but cannot accurately calculate the arrival time, so if most of the echo first wave signals in the echo first wave curve coincide with the starting point of the first wave arrival signal, and the coincidence degree is greater than the threshold, it means that the match is good and the accuracy is high. If the coincidence degree is less than the threshold, it means that the match is poor and the accuracy is poor.

[0107] like Figure 5 As shown in the figure, the experimental data of the first wave arrival time of the ultrasonic echo is displayed. The figure is a waveform time domain diagram, which includes the ultrasonic waveform time domain original signal and the first wave arrival time curve corresponding to different depth labels. The ultrasonic waveform time domain original signal is a number of vertically arranged and horizontally extended waveform curves, and the first wave arrival time curve is a vertically extended broken line. From the comparison results, it can be seen that the first wave arrival time curve and the first wave signal on the ultrasonic waveform time domain original signal are well matched, realizing the accurate extraction of the ultrasonic echo first wave arrival time information.

[0108] The present application also discloses an ultrasonic echo first wave arrival time calculation system, which includes an ultrasonic transducer and a processor, wherein the ultrasonic transducer is used to transmit a pulse sound wave signal and receive the reflected ultrasonic waveform time domain original signal.

[0109] The processor is used to obtain the ultrasonic waveform time domain original signal in real time within the sampling period, obtain the preset time window length and time window step, and obtain the corresponding search starting point information, calculate the ultrasonic waveform time domain original signal according to the time window length, search starting point information and time window step to obtain the corresponding energy product characteristic curve, obtain the maximum value of the energy product curve, and obtain the echo first wave arrival time information according to the time information corresponding to the maximum value of the energy product characteristic curve.

[0110] In other embodiments, a display module is further included. The display module can be a display screen connected to the processor to display the corresponding ultrasonic waveform time domain original signal, energy product characteristic curve, echo first wave arrival time information, etc.

[0111] The present application also discloses a computer storage medium on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned method for calculating the arrival time of the first wave of the ultrasonic echo is implemented.

[0112] The implementation principle is:

[0113] Without changing the existing instrument hardware circuit and mechanical structure, the uncertainty and external influence of the echo first wave arrival time calculation are eliminated by using the energy product algorithm only through the collected ultrasonic waveform time domain original signal, and the ultrasonic echo first wave arrival time information can be accurately extracted.

[0114] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for calculating the arrival time of the first wave of an ultrasonic echo, characterized in that: The following steps are involved: Acquire the original time domain signal of the ultrasonic waveform in real time within the sampling period; Obtain the preset time window length and time window step, and obtain the corresponding search starting point information; Calculating the ultrasonic waveform time domain original signal according to the time window length, the search starting point information and the time window step to obtain a corresponding energy product characteristic curve; Obtaining a maximum value of the energy product characteristic curve; Obtaining the arrival time information of the first echo wave according to the time information corresponding to the maximum value of the energy product characteristic curve; Get the corresponding search starting point information, including: Obtaining the initial point of the sampling period and defining it as the starting reference point, wherein the initial point of the sampling period is characterized as the time point at which the sampling begins; Obtain a sampling period time point after a preset time interval from the starting reference point and define it as an intermediate reference point; Obtaining the ultrasonic waveform time domain original signals corresponding to the starting reference point and the intermediate reference point, and determining whether the difference between the ultrasonic waveform time domain original signals corresponding to the two points is greater than a threshold; If it is greater, the current intermediate reference point is defined as the new initial reference point, and a new intermediate reference point is obtained according to the preset time interval, and the subsequent steps are repeated; If it is less than, the current middle reference point is defined as the search starting point information; After obtaining the arrival time information of the first echo wave, it also includes: Obtaining a plurality of echo first wave arrival information according to different depth labels, and obtaining an echo first wave arrival curve according to the plurality of echo first wave arrival information; Acquire corresponding waveform time domain graphs according to the ultrasonic waveform time domain original signals corresponding to different depth labels; Substituting the echo first wave arrival time curve into the waveform time domain diagram; Determine whether the overlap between the echo first wave arrival curve and the first wave signals on the plurality of ultrasonic waveform time domain original signals in the waveform time domain diagram is greater than a preset overlap value; If it is greater than, it is determined that the arrival time information of the first echo wave is valid; If it is less than, it is determined that the echo first wave arrival time information is invalid.

2. The method for calculating the arrival time of the first ultrasonic echo according to claim 1, characterized in that: Acquire the original ultrasonic waveform time domain signal in real time during the acquisition cycle, including: Get the current depth information to obtain the corresponding depth label; The original ultrasonic waveform time domain signals corresponding to different depth labels are obtained according to the preset depth intervals.

3. The method for calculating the arrival time of the first ultrasonic echo according to claim 2, wherein: After collecting the original time domain signals of the ultrasonic waveforms corresponding to different depth labels, it also includes: The original time-domain information of the ultrasonic waveform is normalized and preprocessed.

4. The method for calculating the arrival time of the first ultrasonic echo according to claim 3, wherein: The ultrasonic waveform time domain original signal is calculated according to the time window length, the search starting point information and the time window step to obtain a corresponding energy product characteristic curve, including: Obtain the depth label corresponding to the initial depth according to the preset depth selection rule; Based on the original time domain signal of the ultrasonic waveform corresponding to the depth tag, the time window energy product sub-eigenvalue is obtained according to the time window energy product algorithm. The time window energy product algorithm is: Among them, C i It is represented by the time window energy product eigenvalue, the operator ".*" represents the multiplication of the corresponding positions of two arrays of the same dimension, Ts represents the search start time, Twin represents the time window length, and Wave represents the original signal of the ultrasonic waveform in the time domain; Moving the time window position according to the time window step size to obtain a plurality of time window energy product sub-eigenvalues ​​within a sampling period; An energy product characteristic curve is obtained according to several time window energy product sub-eigenvalues.

5. An ultrasonic echo first wave arrival time calculation system, characterized by: comprising an ultrasonic transducer and a processor, wherein: The ultrasonic transducer is used to transmit a pulsed sound wave signal and receive the reflected ultrasonic waveform time domain original signal; The processor adopts the ultrasonic echo first wave arrival time calculation method as described in claim 1, which is used to obtain the ultrasonic waveform time domain original signal in real time within the sampling period, obtain the preset time window length and time window step, and obtain the corresponding search starting point information, calculate the ultrasonic waveform time domain original signal according to the time window length, search starting point information and time window step to obtain the corresponding energy product characteristic curve, obtain the maximum value of the energy product curve, and obtain the echo first wave arrival time information according to the time information corresponding to the maximum value of the energy product characteristic curve.

6. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for calculating the ultrasonic echo first wave arrival time according to any one of claims 1 to 4 is implemented.

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