Ultrasound phase correction scan imaging method based on interface peak searching

Abstract

The application provides an ultrasonic phase correction scanning imaging method based on interface peak searching, determines the minimum sampling time difference corresponding to each sampling point in the current ultrasonic signal; takes the product of the minimum sampling time difference corresponding to each sampling point and the amplitude as a peak searching index, and takes the interface peak point with the minimum sampling time sequence in the abnormal value in the peak searching index; calculates the difference between the interface peak point of the current ultrasonic signal and the interface peak point of the last ultrasonic signal as the interface phase deviation of the current ultrasonic signal; if the absolute value of the interface phase deviation of the current ultrasonic signal is greater than the maximum offset, takes the interface peak point of the current ultrasonic signal as the interface reference point of the current ultrasonic signal; calculates the deviation between the interface reference point and the interface peak point of the current ultrasonic signal as a phase correction amount, and performs phase correction on the current ultrasonic signal according to the phase correction amount.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultrasonic technology, and in particular to an ultrasonic phase correction scanning imaging method, device and system based on interface peak searching. BACKGROUND

[0002] In the modern industrial field, with the continuous progress and maturity of process technology, the nondestructive testing industry also develops vigorously. Among them, the ultrasonic flaw detection technology has become an important technical means indispensable in the field of industrial nondestructive testing, with the advantages of high sensitivity, strong penetration, low cost, and no radiation pollution.

[0003] In the ultrasonic flaw detection technology, the ultrasonic echo signals at different positions on the workpiece structure are usually obtained by moving the ultrasonic probe for scanning, the amplitudes of the ultrasonic echo signals at different positions are extracted and arranged, and the internal defect imaging diagram of the workpiece at different angles is realized. However, in the actual ultrasonic scanning imaging process, due to the flatness tolerance when the workpiece is installed, a large perpendicularity tolerance between the ultrasonic probe and the detection surface of the workpiece may be generated. Therefore, the distance between the ultrasonic probe at different positions and the detection surface is different, the collected echo waveforms are advanced or delayed, the phase deviation between the signals is generated, and the ultrasonic imaging formed appears misalignment phenomenon, which affects the detection of internal defects of the measured workpiece. SUMMARY

[0004] The embodiment of the present application provides an ultrasonic phase correction scanning imaging method based on interface peak searching, which can solve the problem that when the distance between the ultrasonic probe at different positions and the detection surface is different, the ultrasonic imaging formed appears misalignment phenomenon.

[0005] In a first aspect, the embodiment of the present application provides an ultrasonic phase correction scanning imaging method based on interface peak searching, which comprises:

[0006] acquiring ultrasonic signals at different positions on the measured object by scanning the surface of the measured object with an ultrasonic probe;

[0007] determining the minimum sampling time difference corresponding to each sampling point in the current ultrasonic signal for the current ultrasonic signal acquired in the moving ultrasonic scanning process;

[0008] taking the product of the minimum sampling time difference and the amplitude of each sampling point as a peak searching index, and determining a plurality of signal peak points according to the abnormal value in the peak searching index;

[0009] taking the signal peak point with the smallest sampling time sequence in the plurality of signal peak points as the interface peak point of the current ultrasonic signal;

[0010] The difference between the interface peak point of the current ultrasound signal and the interface peak point of the previous ultrasound signal is calculated as the interface phase deviation of the current ultrasound signal.

[0011] If the absolute value of the interface phase deviation of the current ultrasound signal is not greater than the maximum offset, then the interface reference point of the previous ultrasound signal before the current ultrasound signal is taken as the interface reference point of the current ultrasound signal. If the absolute value of the interface phase deviation of the current ultrasound signal is greater than the maximum offset, then the interface peak point of the current ultrasound signal is taken as the interface reference point of the current ultrasound signal.

[0012] The deviation between the interface reference point and the interface peak point of the current ultrasound signal is calculated as the phase correction amount, and the current ultrasound signal is phase corrected according to the phase correction amount.

[0013] Ultrasonic images are generated based on phase-corrected ultrasonic signals.

[0014] Optionally, determining the minimum sampling time difference corresponding to each sampling point in the current ultrasound signal includes:

[0015] Time-domain analysis was performed on multiple sampling points in the current ultrasound signal.

[0016] For the sampling point with the largest amplitude among the multiple sampling points m Based on its sampling time sequence m and N - m The maximum value in the range is taken as the maximum sampling point of the amplitude. m The minimum sampling time difference;

[0017] For the sampling points among the multiple sampling points, the amplitude is not the largest. i :

[0018] Obtain the amplitude greater than the sampling point i Multiple other sampling points of amplitude j Determine the multiple other sampling points j With sampling points i The sampling time difference between multiple sampling time differences is used as the sampling point, with the smallest absolute value among them. i The minimum sampling time difference, where, N This represents the total number of sampling points in the current ultrasound signal. m , i , j Characterizes the sampling timing of sampling points, and m , i , j All less than or equal to N .

[0019] Optionally, the product of the minimum sampling time difference corresponding to each sampling point and the amplitude is taken as a peak searching index, a plurality of signal peak points are determined according to abnormal values in the peak searching index, and the method comprises the following steps.

[0020] The peak searching index of all sampling points of the current ultrasonic signal is statistically distributed, a plurality of deviation values in the peak searching index of all sampling points are calculated, and a plurality of sampling points corresponding to the plurality of deviation values are taken as the plurality of signal peak points.

[0021] Optionally, the plurality of deviation values in the peak searching index of all sampling points are calculated, and the method comprises the following steps.

[0022] The mean value and the standard deviation of the peak searching index of all sampling points of the current ultrasonic signal are calculated.

[0023] If the difference between the peak searching index and the mean value is greater than three times the standard deviation, the corresponding sampling point is determined as a signal peak point.

[0024] Optionally, after the interface phase deviation of the current ultrasonic signal is determined, the method further comprises the following steps.

[0025] The interface peak point of the first ultrasonic signal is taken as an interface reference point of the first ultrasonic signal.

[0026] Optionally, the phase correction of the current ultrasonic signal based on the phase correction amount comprises the following steps.

[0027] If the phase correction amount is e, when e is less than 0, the current ultrasonic signal is moved to the left by e sampling point positions; and when e is greater than 0, the current ultrasonic signal is moved to the right by e sampling point positions.

[0028] Optionally, the ultrasonic image is generated based on the ultrasonic signal after phase correction, and the method comprises the following steps.

[0029] The ultrasonic signal after phase correction is superimposed and spliced according to three dimensions to obtain a signal space-time domain three-dimensional imaging space, the three dimensions comprising two mutually perpendicular horizontal scanning directions in a two-dimensional scanning surface and a signal flight direction perpendicular to the two-dimensional scanning surface, and each position in the space has a corresponding ultrasonic signal amplitude;

[0030] In the signal space-time domain three-dimensional imaging space, the signal amplitudes at the same position in any one dimension are arranged and displayed according to the positions of the remaining two dimensions, respectively forming ultrasonic B scan, D scan and C scan images.

[0031] Optionally, the ultrasonic image is generated based on the ultrasonic signal after phase correction, and the method comprises the following steps.

[0032] After phase correction is performed on all the ultrasonic signals obtained at different positions along the scanning surface of the measured object,

[0033] Based on the corrected ultrasonic signals at different positions, the propagation time of the ultrasonic signals perpendicular to the scanning surface of the measured object is extracted and displayed according to the positions corresponding to the ultrasonic signals, so as to form an ultrasonic B-scan image of the measured object.

[0034] Optionally, based on the corrected ultrasonic signals at different positions, the signal amplitudes at the same sampling time sequence are extracted and arranged into an image according to the scanning positions of the ultrasonic signals at different positions, including:

[0035] In the three-dimensional imaging space of the signal space-time domain, a first signal amplitude sequence of each position in the first horizontal scanning direction within the two-dimensional scanning surface is sequentially obtained, and the first signal amplitude sequence is arranged according to the positions in the second horizontal scanning direction and the sampling time sequence in the signal flight direction, so as to form an ultrasonic B-scan image section of the measured object.

[0036] In the three-dimensional imaging space of the signal space-time domain, a second signal amplitude sequence of each position in the second horizontal scanning direction within the two-dimensional scanning surface is sequentially obtained, and the second signal amplitude sequence is arranged according to the positions in the first horizontal scanning direction and the sampling time sequence in the signal flight direction, so as to form an ultrasonic D-scan image section perpendicular to the B-scan image section.

[0037] The third signal amplitude sequence at the same sampling time sequence in the signal flight direction is arranged according to the scanning positions, so as to form an ultrasonic C-scan image section.

[0038] In a second aspect, an embodiment of the present application provides an ultrasonic phase correction scanning imaging system based on interface peak value searching, including an ultrasonic probe, a processor and a display,

[0039] The ultrasonic probe is configured to send ultrasonic waves to the measured object.

[0040] The processor is configured to receive ultrasonic signals corresponding to the ultrasonic waves, perform phase correction on the ultrasonic signals by using the ultrasonic phase correction scanning imaging method based on interface peak value searching, and generate an ultrasonic image of the measured object.

[0041] The display is configured to display the ultrasonic image.

[0042] In a third aspect, an embodiment of the present application provides an ultrasonic phase correction scanning imaging device based on interface peak value searching, including:

[0043] A processor;

[0044] A memory having computer readable instructions stored thereon, the computer readable instructions, when executed by the processor, implement the method.

[0045] The application firstly counts the minimum sampling time difference and amplitude corresponding to each sampling point in the current ultrasonic signal, and according to the two characteristics that the interface peak point has the minimum sampling time difference and the maximum amplitude, the product of the minimum sampling time difference and the amplitude is taken as the search index of the interface echo peak value of the measured object on the ultrasonic signal, and the interface peak point of the current ultrasonic signal is automatically and accurately determined through the abnormal situation of the peak search index and the corresponding sampling time sequence; the phase correction is performed on the current ultrasonic signal according to the phase deviation between the interface reference point of the previous ultrasonic signal and the interface peak point of the current ultrasonic signal. Since the ultrasonic signal phase correction process based on the interface peak search does not need to pre-set initial parameters such as interface gate, threshold and the like, the interface reference points of the ultrasonic signals at different positions of the same scanning surface of the measured object can be dynamically tracked and determined, therefore, the application can solve the problem of misalignment of the ultrasonic imaging formed when the distance between the ultrasonic probe at different positions and the detection surface exists difference, eliminate the misalignment, drift and the like of the ultrasonic image, at the same time, the interface peak determination error and the corresponding phase correction error caused by the fixed width of the interface gate can be suppressed, the quality and detection precision of the ultrasonic image are significantly improved, the whole correction process is simple and efficient, and it is beneficial to realize the online ultrasonic scanning imaging of automatic phase correction. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0047] Figure 1 is an ultrasonic C-scan imaging distortion diagram of related art;

[0048] Figure 2 is an ultrasonic B-scan imaging distortion diagram of related art;

[0049] Figure 3 is an ultrasonic D-scan imaging distortion diagram of related art;

[0050] Figure 4 is a flowchart of an ultrasonic phase correction scanning imaging method based on interface peak search provided by an embodiment of the application;

[0051] Figure 5 is an ultrasonic signal diagram of the same Y axis at different X axis positions on the upper surface of an aluminum plate provided by an embodiment of the application;

[0052] Figure 6 is a schematic diagram of interface peak points of ultrasonic signals at different X-axis positions of the same Y-axis position of the upper surface of the aluminum plate provided by an embodiment of the present application;

[0053] Figure 7 is a schematic diagram of ultrasonic signals after phase correction at different X-axis positions of the same Y-axis position of the upper surface of the aluminum plate provided by an embodiment of the present application;

[0054] Figure 8 is a schematic diagram of an ultrasonic C-scan image after phase correction provided by an embodiment of the present application;

[0055] Figure 9 is a schematic diagram of an ultrasonic B-scan image after phase correction provided by an embodiment of the present application;

[0056] Figure 10 is a schematic diagram of an ultrasonic D-scan image after phase correction provided by an embodiment of the present application. DETAILED DESCRIPTION

[0057] The present application will be described in detail below with reference to the specific embodiments shown in the drawings, but these embodiments do not limit the present application, and the structural, method, or functional changes made by those of ordinary skill in the art based on these embodiments are included in the protection scope of the present application.

[0058] In an actual ultrasonic scanning imaging process, due to the flatness tolerance of the workpiece during installation, there is a perpendicularity tolerance between the ultrasonic probe and the detection surface of the workpiece, and there is a phase deviation between the received echo waveforms in the ultrasonic scanning imaging process, which causes the ultrasonic imaging to be misaligned. For example, the ultrasonic C-scan image of the upper surface of a cuboid aluminum block with a flat surface is shown in FIG. 1, where the x-axis and the y-axis are two mutually perpendicular probe scanning directions; without phase correction, the ultrasonic B-scan image of the workpiece at the same x-axis is shown in FIG. 2, and the ultrasonic D-scan image of the workpiece at the same y-axis is shown in FIG. 3. Figure 1 Figure 2 Figure 3 ​​As shown. It can be seen that due to the non-horizontal placement of the workpiece, there is a phase deviation between the signal echoes, which finally leads to the uneven pixels in the ultrasonic C-scan image, the tilt of the workpiece surface horizontal line in the B-scan and D-scan images. In the related art, the interface gate is usually preset to determine the interface echo of the workpiece. The phase deviation of the workpiece at different positions is corrected according to the alignment of the interface echo. After the signal is vertically incident on the workpiece, a reflected echo is generated at the interface between the coupling agent and the workpiece. The time range set to select the interface reflected echo is the interface gate. In this way, the initial parameters such as the wedge height need to be input in advance, or the interface gate parameters are manually set according to the position of the interface echo obtained by pre-scan. The width of the interface gate cannot be automatically adjusted during the ultrasonic scanning process. The interface gate with a fixed width may not be able to capture the interface echo at all positions of the workpiece, which may lead to misjudgment of the interface echo at some positions, and the ultrasonic imaging is misaligned, affecting the detection of defects. The present application can dynamically determine the sampling point of the interface echo peak of the workpiece during the ultrasonic scanning process, and then align the echo signal according to the interface echo peak sampling point, realize online phase correction of the echo signal, and solve the problem of misalignment of ultrasonic scanning imaging caused by the distance deviation between the ultrasonic probe and the scanning surface of the workpiece, and realize automatic phase correction of ultrasonic scanning imaging.

[0059] Please refer to Figure 4 The embodiment of the present application provides an ultrasonic phase correction scanning imaging method based on interface peak searching, which comprises steps S401-S408.

[0060] S401: acquiring ultrasonic signals at different positions on the measured object by scanning the surface of the measured object with an ultrasonic probe;

[0061] S402: determining the minimum sampling time difference corresponding to each sampling point in the current ultrasonic signal acquired during the movement of the ultrasonic scanning process;

[0062] S403: taking the product of the minimum sampling time difference and the amplitude of each sampling point as a peak searching index, and determining a plurality of signal peak points according to the abnormal values in the peak searching index;

[0063] S404: taking the signal peak point with the smallest sampling time sequence in the plurality of signal peak points as the interface peak point of the current ultrasonic signal;

[0064] S405: calculating the difference between the interface peak point of the current ultrasonic signal and the interface peak point of the last ultrasonic signal as the interface phase deviation of the current ultrasonic signal;

[0065] S406: If the absolute value of the interface phase deviation of the current ultrasonic signal is not greater than the maximum deviation, the interface reference point of the last ultrasonic signal before the current ultrasonic signal is taken as the interface reference point of the current ultrasonic signal.

[0066] S407: If the absolute value of the interface phase deviation of the current ultrasonic signal is greater than the maximum deviation, the interface peak point of the current ultrasonic signal is taken as the interface reference point of the current ultrasonic signal.

[0067] S408: The deviation between the interface reference point of the current ultrasonic signal and the interface peak point of the current ultrasonic signal is calculated as a phase correction amount, the current ultrasonic signal is phase corrected according to the phase correction amount, and an ultrasonic image is generated based on the phase-corrected ultrasonic signal.

[0068] The object to be measured is scanned using an ultrasonic probe, the ultrasonic probe emits ultrasonic pulses, when the pulses encounter the scanning interface (for example, the surface of the object to be measured) of the object to be measured, echoes are generated, and when different positions of the scanning interface are scanned, echo signals at different positions are obtained, that is, ultrasonic signals at different positions can be obtained. The echo signal at each position is composed of signal amplitude values collected by the ultrasonic probe at the position within a set time according to a sampling frequency. Since the sampling frequency refers to the number of sampling points per unit time, the echo signal at each position is composed of signal amplitude values collected by the ultrasonic probe at multiple sampling points, so the ultrasonic signal usually includes the corresponding relationship between the sampling points and the signal amplitude values. Therefore, the abscissa of the ultrasonic signal can be expressed as the number of sampling points, and the ordinate represents the amplitude (amplitude) of the ultrasonic wave. Further, the sampling points can be converted into the propagation time of the ultrasonic wave according to the sampling frequency, and further converted into the propagation distance according to the propagation speed of the ultrasonic wave in the medium. During real-time scanning of the object to be measured by the ultrasonic probe, the current ultrasonic signal at the current position of the object to be measured is obtained.

[0069] For each sampling point in the current ultrasonic signal, determine the minimum sampling time difference between it and the sampling point with a larger amplitude value; take the product of the minimum sampling time difference and the amplitude value of each sampling point as a peak searching index, and determine a plurality of signal peak points according to the abnormality of the peak searching index; take the signal peak point with the minimum sampling time sequence as the interface peak point of the current ultrasonic signal. From the above description of the ultrasonic signal, the interface peak point refers to the sampling point corresponding to the peak value of the reflected echo at the interface between the coupling agent and the measured object after the signal is vertically incident on the measured object, which corresponds to the first strong reflected wave generated at the most surface of the measured object, i.e., the probe incidence interface, and can be understood as the starting point of the ultrasonic wave entering the measured object. Therefore, the signal peak point with the minimum sampling time sequence is taken as the interface peak point of the current ultrasonic signal. The local maximum characteristics of the amplitude of the sampling point and the local maximum characteristics of the minimum distance between the sampling point and other sampling points are combined as the basis for determining the interface peak point, and according to the characteristic that the interface peak point is the first peak point, the interface peak point on the ultrasonic signal can be accurately and automatically determined.

[0070] In the actual ultrasonic scanning process, due to the uneven surface of the measured object, the change of the probe posture (angle / height), etc., the appearance time of the interface echo (i.e., the starting point of the ultrasonic wave entering the measured object) at each position is different, and therefore it is necessary to determine the interface reference point of the echo signal at each position. In the ultrasonic scanning process, the interface peak point of the current ultrasonic signal is continuously compared with the interface reference point of the previous ultrasonic signal to determine the interface phase deviation of the current ultrasonic signal, and the current ultrasonic signal is phase corrected based on the interface phase deviation.

[0071] Exemplarily, if the absolute value of the interface phase deviation is greater than the maximum offset, the interface peak point of the current ultrasonic signal is taken as the interface reference point of the current ultrasonic signal; if the absolute value of the interface phase deviation is less than or equal to the maximum offset, the current ultrasonic signal is phase corrected according to the interface phase deviation, and the interface reference point of the previous ultrasonic signal is taken as the interface reference point of the current ultrasonic signal. In the ultrasonic scanning process, the interface reference point of each ultrasonic signal is automatically adjusted directly according to the interface peak point of the signal at each position.

[0072] In this embodiment, the minimum sampling time difference and amplitude corresponding to each sampling point in the current ultrasonic signal are first statistically analyzed. Based on the characteristics of the interface peak point being both extremely small in the minimum sampling time difference and extremely large in the amplitude, the product of the minimum sampling time difference and the amplitude is used as the search index for the peak value of the interface echo of the measured object on the ultrasonic signal. By analyzing abnormal peak search index conditions and the corresponding sampling sequence, the interface peak point of the current ultrasonic signal is automatically and accurately determined. Based on the phase deviation between the interface reference point of the previous ultrasonic signal and the interface peak point of the current ultrasonic signal, phase correction is performed on the current ultrasonic signal. This is because the ultrasonic signal phase correction process is based on interface peak search. Without the need to pre-set initial parameters such as interface gate and threshold, this invention can dynamically track and determine the interface reference point of the ultrasonic signal at different positions on the same scanning surface of the object under test. Therefore, this application can solve the problem of misalignment in ultrasonic imaging when the distance between the ultrasonic probe and the detection surface varies at different positions, eliminating misalignment and drift of ultrasonic images. At the same time, it can suppress the interface peak determination error and corresponding phase correction error caused by the fixed width of the interface gate, significantly improving the quality and detection accuracy of ultrasonic images. The entire correction process is simple and efficient, which is conducive to realizing automated phase correction online ultrasonic scanning imaging.

[0073] One embodiment of this application involves determining the minimum sampling time difference between multiple sampling points in the current ultrasound signal and other sampling points, including:

[0074] Time-domain analysis was performed on multiple sampling points in the current ultrasound signal, and the sampling point with the largest amplitude among the multiple sampling points was selected. m Based on its sampling time sequence m and N - m The maximum value in the range is taken as the maximum sampling point of the amplitude. m The minimum sampling time difference; for the sampling points among the multiple sampling points whose amplitude is not the largest. i Obtain the amplitude greater than the sampling point i Multiple other sampling points of amplitude j Determine the multiple other sampling points j With sampling points i The sampling time difference between multiple sampling time differences is used as the sampling point, with the smallest absolute value among them. i The minimum sampling time difference; where, N This represents the total number of sampling points in the current ultrasound signal. m , i , j Characterizes the sampling timing of sampling points, and m , i , j All less than or equal to N .

[0075] Exemplarily, the minimum sampling time difference of a sampling point i in the current ultrasound signal is represented as: S i

[0076]

[0077]

[0078] wherein, d ij i j x i i x j j x j x i

[0079] If the amplitude of the ultrasound signal at the mth sampling point x m is the maximum, the minimum sampling time difference thereof is S m = max( m , N-m ).

[0080] Exemplarily, the minimum sampling time difference can represent the number of sampling intervals between the sampling point j and the sampling point j, and the unit thereof can be the number of sampling points. When the amplitude of the ultrasound signal at the mth sampling point is the maximum, the maximum of the sampling time sequence m and the sampling time sequence N-m can be taken as the minimum sampling time difference of the mth sampling point.

[0081] In an embodiment of the present application, a plurality of time difference domain abnormal sampling points are determined based on the minimum sampling time difference corresponding to each sampling point and the amplitude, comprising:

[0082] For each sampling point of the current ultrasound signal, the product of the amplitude of the sampling point and the minimum sampling time difference corresponding to the sampling point is calculated as a peak searching index; a plurality of deviation values in the peak searching indexes of all sampling points in the current ultrasound signal are determined, and a plurality of sampling points corresponding to the plurality of deviation values are taken as a plurality of signal peak points. Among the plurality of signal peak points, the signal peak point with the minimum sampling time sequence is taken as the interface peak point of the current ultrasound signal.

[0083] ​​​​​​​​​​​​​​​​​​​The peak point in the ultrasonic signal usually has the characteristics of maximum amplitude and minimum sampling time difference between other sampling points with greater amplitude. By taking the product of the amplitude of the sampling point and the minimum sampling time difference as the peak searching index, combining the local maximum characteristics of the amplitude of the sampling point and the local maximum characteristics of the minimum sampling time difference, the sampling points are screened, and a few sampling points with large peak value and minimum sampling time difference are screened as signal peak points, and the interface wave peak points returned by the workpiece surface are included in these signal peak points. Therefore, based on this, in combination with the characteristics that the interface peak points usually arrive first, the interface peak points can be accurately and automatically determined.

[0084] In an embodiment of the present application, the plurality of deviation values in the peak searching index of all sampling points in the current ultrasonic signal are determined, including: calculating the mean and standard deviation of the peak searching index of all sampling points in the current ultrasonic signal; if the difference between the peak searching index and the mean is greater than three times the standard deviation, the corresponding sampling point is determined as a signal peak point. The distribution of the peak searching index can be regarded as a Gaussian distribution, and the maximum value in the index has a very low probability of occurrence. Therefore, the mean and standard deviation of the peak searching index of all sampling points are used as screening conditions to screen the sampling points, the maximum value in the peak searching index can be screened, and the interface peak point of the current ultrasonic signal can be determined.

[0085] Exemplarily, for a sampling point in the ultrasonic signal i , the product of the amplitude i of the sampling point and the minimum sampling time difference i corresponding to the sampling point is taken as the peak searching index , if , the corresponding sampling point i is a signal peak point, , the mean of the peak searching index of all sampling points, , the standard deviation of the peak searching index of all sampling points. In a specific embodiment of the present application, when an aluminum plate is scanned, the ultrasonic signals at different X-axis positions on the same Y-axis of the upper surface of the aluminum plate are as shown in Figure 5 , it can be seen that there is indeed a phase deviation between the ultrasonic signals. By using the embodiment of the present application, the interface peak points of the ultrasonic signals at different X-axis positions on the same Y-axis of the upper surface of the aluminum plate are automatically determined, and the interface peak points are as shown in Figure 6 .

[0086] Exemplarily, the interface phase deviation of the first ultrasonic signal in the scanning process is set to 0. For the current ultrasonic signal, the previous ultrasonic signal can be understood as the ultrasonic signal obtained by the previous probe scanning in the continuous scanning process. The interface peak point Pn the difference between the interface peak point P of the previous ultrasound signal n-1 , the interface phase deviation M of the current ultrasound signal n , i.e. M n = P n - P n-1 . If M n is not 0, it indicates that the interface position of the adjacent two scanning points jumps, for example, caused by the inequality of the surface of the measured object, and the phase of the current ultrasound signal needs to be adjusted based on the interface phase deviation. For example, if M n is less than 0, it means that there is a convex part on the surface of the measured object during the current scanning, resulting in the phase of the interface echo of the ultrasound signal being advanced; if M n is greater than 0, it means that there is a concave part on the surface of the measured object during the current scanning, resulting in the phase of the interface echo of the ultrasound signal being delayed.

[0087] Exemplarily, the interface peak point of the first ultrasound signal is taken as the interface reference point of the first ultrasound signal. During the scanning process, if the absolute value of the interface phase deviation M of the current ultrasound signal n is less than or equal to the preset maximum deviation, the interface reference point R of the previous ultrasound signal n-1 is taken as the interface reference point R of the current ultrasound signal n ; if the absolute value of the interface phase deviation M of the current ultrasound signal n is greater than the preset maximum deviation, the interface peak point P of the current ultrasound signal n is taken as the interface reference point R of the current ultrasound signal n .

[0088] The maximum displacement can be set according to the actual scanning requirements of the ultrasound and the shape of the surface of the measured workpiece. Exemplarily, the maximum displacement is set to 100 sampling points.

[0089] During the scanning process of the ultrasound probe on the measured object, the phase of the current ultrasound signal is corrected according to the deviation between the interface reference point and the interface peak point of the current ultrasound signal, so as to align the ultrasound signal according to the interface echo and compensate for the phase deviation of the ultrasound signal caused by the placement of the workpiece and the shaking of the probe. During the entire scanning process, the interface peak point of each scanning point is constantly searched and the interface reference point is adjusted, without the need to set initial parameters such as interface gate and threshold, which can solve the problem of scanning signal phase deviation caused by the vertical tolerance between the ultrasound probe and the detection surface at different positions, can suppress the error of interface peak determination and the corresponding phase correction error caused by the fixed width of the interface gate, the entire correction process is simple and efficient, and the quality and detection accuracy of the ultrasound image are significantly improved.

[0090] In one embodiment of the present application, the current ultrasonic signal is phase-corrected according to the deviation between the interface reference point and the interface peak point of the current ultrasonic signal, including: calculating the deviation between the interface reference point of the current ultrasonic signal and the interface peak point of the current ultrasonic signal, and taking the deviation as the phase correction amount of the current ultrasonic signal, and phase-correcting the current ultrasonic signal according to the phase correction amount. In the embodiment of the present application, the ultrasonic signals at the same Y-axis and different X-axis positions on the upper surface of the aluminum plate are phase-corrected, and the phase-corrected ultrasonic signals are as shown in FIG. 3. Figure 7

[0091] For example, the difference between the interface reference point R n and the interface peak point P n of the current ultrasonic signal is taken as the phase correction amount, and the phase correction amount is denoted as e, and the calculation formula of e is: e = R n -P n .

[0092] In the actual ultrasonic scanning process, when the surface of the measured object is not horizontal due to placement or other factors, the time of ultrasonic waves incident on the measured object at each scanning point is not the same, resulting in that the ultrasonic signals that should be aligned do not have a uniform starting point, and there is a phase deviation between the signals. Therefore, it is necessary to align the ultrasonic signals at each scanning point, compensate for the phase deviation, make the interface peak positions of the ultrasonic signals corresponding to the workpiece plane consistent, so as to eliminate the phenomena of ultrasonic image misplacement and distortion.

[0093] For example, if the phase correction amount e is less than 0, the current ultrasonic signal is moved to the left by e sample point positions, and if the phase correction amount e is greater than 0, the current ultrasonic C-scan signal is moved to the right by e sample point positions.

[0094] In one embodiment of the present application, after phase-correcting all the ultrasonic signals obtained along the scanning surface of the measured object, the method further includes: superimposing and splicing the phase-corrected ultrasonic signals according to three dimensions to obtain a signal space-time domain three-dimensional imaging space, the three dimensions including: two mutually perpendicular horizontal scanning directions in the two-dimensional scanning surface and the signal flight direction perpendicular to the two-dimensional scanning surface, and each position in the space has a corresponding ultrasonic signal amplitude.

[0095] In the signal space-time domain three-dimensional imaging space, the signal amplitudes at the same position in any one dimension are arranged and displayed according to the positions of the remaining two dimensions, respectively forming ultrasonic B-scan, D-scan and C-scan images.

[0096] For example, the two-dimensional scanning surface can be a two-dimensional scanning surface along which the ultrasonic probe scans the measured object.

[0097] ​The above process of forming the ultrasound B-scan, D-scan and C-scan images respectively can be realized by the following way, but is not limited thereto: in the signal space-time domain three-dimensional imaging space, a first signal amplitude sequence of each position in a first horizontal scanning direction within a two-dimensional scanning plane is sequentially acquired, the first signal amplitude sequence is arranged according to the position in a second horizontal scanning direction and the sampling time sequence in the signal flight direction, thereby forming an ultrasound B-scan image section of the measured object;

[0098] In the signal space-time domain three-dimensional imaging space, a second signal amplitude sequence of each position in a second horizontal scanning direction within a two-dimensional scanning plane is sequentially acquired, the second signal amplitude sequence is arranged according to the position in a first horizontal scanning direction and the sampling time sequence in the signal flight direction, thereby forming an ultrasound D-scan image section perpendicular to the B-scan image section;

[0099] The third signal amplitude sequence of the same sampling time sequence in the signal flight direction is arranged according to the scanning position, thereby forming an ultrasound C-scan image section.

[0100] For the ultrasound signals within a two-dimensional scanning plane collected in the same period of time, the above first signal amplitude sequence, second signal amplitude sequence and third signal amplitude sequence can be the signal amplitudes of different positions in the same signal space-time domain three-dimensional imaging space, which are collected according to any one dimension and arranged and displayed according to the remaining two dimensions. In this way, the ultrasound wave signals are collected once, and the signal space-time domain three-dimensional imaging space is obtained after phase correction, and the signal amplitudes in the signal space-time domain three-dimensional imaging space are converted to obtain the ultrasound B-scan, D-scan and C-scan images in parallel, thereby saving the processing time.

[0101] When the C-scan image of a specified depth of the measured object needs to be drawn, since the probe signal is perpendicular to the internal of the measured object, the ultrasound signal flight time corresponding to the specified depth can be calculated according to the propagation speed of the ultrasound signal in the measured object, all signal amplitudes of the same flight time in the signal space-time domain three-dimensional imaging space are selected, the signal amplitudes are arranged and displayed according to the corresponding scanning positions, thereby forming the ultrasound C-scan image of the specified depth of the measured object, such as the C-scan image of the upper surface of the measured object after phase correction as shown in Figure 8 The signal amplitudes are compared with Figure 1 the C-scan image without phase correction, Figure 8 the pixel distribution in the C-scan image after phase correction is more uniform.

[0102] When the B-scan and D-scan images of a specified position of the measured object need to be drawn, in the signal space-time domain three-dimensional imaging space, the signal amplitudes of the same position in one scanning direction within a two-dimensional scanning plane are arranged according to the position in the other scanning direction and the sampling time sequence in the signal flight direction, thereby forming the ultrasound B-scan and D-scan image sections of the measured object.

[0103] For example, when the signal amplitudes of the same position on the x-axis are arranged according to the y-axis positions and the signal flight directions, a B-scan image is formed; when the signal amplitudes of the same position on the y-axis are arranged according to the x-axis positions and the signal flight directions, a D-scan image is formed.

[0104] Figure 9 and Figure 10 The B-scan and D-scan images obtained after phase correction of the ultrasonic signals represented by and respectively. Compared with Figure 2 、 Figure 3 The B-scan and D-scan images without phase correction, Figure 9 The uppermost horizontal line in the B-scan image of Figure 10 The D-scan image of Figure 9 and 10 It can be seen from the horizontal lines eliminated in and that the method of the present application eliminates the phase deviation of the scanning signals caused by the vertical tolerance between the ultrasonic probe and the scanning surface of the measured object.

[0105] In one embodiment of the present application, the present application provides an ultrasonic phase correction scanning imaging system based on interface peak searching, comprising an ultrasonic probe, a processor and a display,

[0106] The ultrasonic probe is configured to send ultrasonic waves to the measured object.

[0107] The processor is configured to receive ultrasonic signals corresponding to the ultrasonic waves, perform phase correction on the ultrasonic signals by using the ultrasonic phase correction scanning imaging method based on interface peak searching, and generate an ultrasonic image of the measured object.

[0108] The display is configured to display the ultrasonic image.

[0109] The present application also provides an ultrasonic phase correction scanning imaging device based on interface peak searching, comprising a processor and a memory, wherein the memory stores computer readable instructions, and the computer readable instructions are executed by the processor to implement the steps of any one of the above ultrasonic phase correction scanning imaging methods based on interface peak searching.

[0110] The application firstly counts the minimum sampling time difference and amplitude corresponding to each sampling point in the current ultrasonic signal, and according to the two characteristics that the interface peak point has the minimum sampling time difference and the maximum amplitude, the product of the minimum sampling time difference and the amplitude is taken as the search index of the interface echo peak value of the measured object on the ultrasonic signal, and the interface peak point of the current ultrasonic signal is automatically and accurately determined through the abnormal situation of the peak value search index and the corresponding sampling time sequence; the phase of the current ultrasonic signal is corrected according to the phase deviation between the interface reference point of the previous ultrasonic signal and the interface peak point of the current ultrasonic signal. Since the ultrasonic signal phase correction process based on the interface peak value search does not need to pre-set initial parameters such as interface gate and threshold, the interface reference points of the ultrasonic signals at different positions of the same scanning surface of the measured object can be dynamically tracked and determined, therefore, the application can solve the problem of misalignment of the ultrasonic imaging formed when the distance between the ultrasonic probe at different positions and the detection surface is different, eliminate the misalignment and drift of the ultrasonic image, and at the same time, suppress the interface peak value determination error and the corresponding phase correction error caused by the fixed width of the interface gate, significantly improve the quality and detection accuracy of the ultrasonic image, and the whole correction process is simple and efficient, which is beneficial to realize the online ultrasonic scanning imaging of automatic phase correction.

[0111] In the embodiments of the present application, the memory can be various types of storage media, such as random access memory (RAM), read only memory (ROM), non-volatile RAM (NVRAM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), flash memory, optical storage, and registers, etc. The memory can include a hard disk and / or an internal memory.

[0112] The processor can be a general-purpose processor, which can be a processor that performs specific steps and / or operations by reading and executing a computer program (such as a computer program) stored in the memory, and can use data stored in the memory in the process of executing the steps and / or operations. The general-purpose processor can be, for example but not limited to, a central processing unit (CPU). In addition, the processor can also be a special-purpose processor, which can be a processor specially designed to perform specific steps and / or operations, and can be, for example but not limited to, ASIC and FPGA, etc. In addition, the processor can also be a combination of multiple processors, such as a multi-core processor.

[0113] In the implementation process, each step of the above method can be completed by the integrated logic circuit of hardware in the processor or the instruction in the form of software. The method disclosed in combination with the embodiments of the present application can be directly embodied as hardware processor execution completion, or executed by hardware and software modules in the processor. The software module can be located in a mature storage medium in the art such as random access memory flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, register, etc. The storage medium is located in the memory, and the processor reads the information in the memory, and combines the hardware to complete the steps of the above method. To avoid repetition, it will not be described in detail here.

[0114] It should be understood that the term "and / or" herein merely describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone, wherein A and B can be singular or plural. In addition, the character " / " herein generally represents that the front and rear associated objects are in an "or" relationship, but can also represent an "and / or" relationship, which can be understood in combination with the context.

[0115] In the present application, "at least one" means one or more, and "a plurality of" means two or more. "At least one of the following" or similar expressions means any combination of these items, including any combination of single item or multiple items. For example, at least one of a, b, or c can represent a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, and c can be single or multiple.

[0116] It should be noted that in this paper, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or equipment including the element.

[0117] Each of the embodiments in the specification is described in a relevant manner, and the same or similar parts between the embodiments can be referred to each other. Each of the embodiments focuses on the difference from other embodiments. In particular, for the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiments.

[0118] The above merely describes the preferred embodiments of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An ultrasound phase correction scan imaging method based on interface peak searching, characterized in that, The method comprises: acquiring an ultrasonic signal at different positions on the measured object by scanning the surface of the measured object with an ultrasonic probe; determining a minimum sampling time difference corresponding to each sampling point in the current ultrasonic signal acquired in the moving ultrasonic scanning process; taking the product of the minimum sampling time difference and the amplitude of each sampling point as a peak searching index, and determining a plurality of signal peak points according to abnormal values in the peak searching index; taking the signal peak point with the minimum sampling time sequence in the plurality of signal peak points as an interface peak point of the current ultrasonic signal; calculating the difference between the interface peak point of the current ultrasonic signal and the interface peak point of the last ultrasonic signal as an interface phase deviation of the current ultrasonic signal; if the absolute value of the interface phase deviation of the current ultrasonic signal is not greater than a maximum deviation, taking the interface reference point of the last ultrasonic signal before the current ultrasonic signal as the interface reference point of the current ultrasonic signal, and if the absolute value of the interface phase deviation of the current ultrasonic signal is greater than the maximum deviation, taking the interface peak point of the current ultrasonic signal as the interface reference point of the current ultrasonic signal; calculating the deviation between the interface reference point of the current ultrasonic signal and the interface peak point of the current ultrasonic signal as a phase correction amount, and performing phase correction on the current ultrasonic signal according to the phase correction amount; generating an ultrasonic image based on the ultrasonic signal after phase correction, the determination of the minimum sampling time difference corresponding to each sampling point in the current ultrasonic signal comprises: time domain analysis of a plurality of sampling points in the current ultrasonic signal, For the sampling point with the largest amplitude in the plurality of sampling points, taking the maximum value in the amplitude of the sampling point and the amplitude of the sampling point m and N - m as the minimum sampling time difference of the sampling point with the largest amplitude m . for a sampling point in the plurality of sampling points i : acquiring a plurality of other sampling points with amplitudes greater than the sampling point i , j , j , i , i , N , m , i , j , m , i , j , N .

2. The method of claim 1, wherein, the taking of the product of the minimum sampling time difference and the amplitude of each sampling point as a peak searching index, and the determination of a plurality of signal peak points according to abnormal values in the peak searching index, comprises: distribution statistics of all sampling points of the current ultrasonic signal, calculation of a plurality of deviation values in the peak searching index of all sampling points, and taking a plurality of sampling points corresponding to the plurality of deviation values as the plurality of signal peak points.

3. The method of claim 2, wherein, the calculation of a plurality of deviation values in the peak searching index of all sampling points, comprises: calculation of the mean value and the standard deviation of the peak searching index of all sampling points in the current ultrasonic signal; if the difference between the peak searching index and the mean value is greater than three times the standard deviation, the corresponding sampling point is determined to be a signal peak point.

4. The method of claim 1, wherein, after taking the signal peak point with the minimum sampling time sequence in the plurality of signal peak points as the interface peak point of the current ultrasonic signal, the method further comprises: taking the interface peak point of the first ultrasonic signal as the interface reference point of the first ultrasonic signal.

5. The method of claim 1, wherein, the phase correction on the current ultrasonic signal based on the phase correction amount, comprises: if the phase correction amount is e, moving the current ultrasonic signal left by e sampling point positions when e is less than 0, and moving the current ultrasonic signal right by e sampling point positions when e is greater than 0.

6. The method of claim 1, wherein, the generation of an ultrasonic image based on the ultrasonic signal after phase correction, comprises: The phase-corrected ultrasonic signals are superimposed and spliced according to three dimensions to obtain a signal space-time domain three-dimensional imaging space, the three dimensions including two mutually perpendicular horizontal scanning directions in a two-dimensional scanning plane and a signal flight direction perpendicular to the two-dimensional scanning plane, and each position in the space has a corresponding ultrasonic signal amplitude; In the signal space-time domain three-dimensional imaging space, the signal amplitudes at the same position in any one dimension are arranged and displayed according to the positions of the remaining two dimensions, respectively forming ultrasonic B-scan, D-scan and C-scan images.

7. The method of claim 6, wherein, The signal space-time domain three-dimensional imaging space, the signal amplitudes at the same position in any one dimension are arranged and displayed according to the positions of the remaining two dimensions, respectively forming ultrasonic B-scan, D-scan and C-scan images, including: In the signal space-time domain three-dimensional imaging space, a first signal amplitude sequence of each position in a first horizontal scanning direction in the two-dimensional scanning plane is sequentially obtained, and the first signal amplitude sequence is arranged according to the positions of the second horizontal scanning direction and the sampling time sequence in the signal flight direction to form an ultrasonic B-scan image section of the measured object. In the signal space-time domain three-dimensional imaging space, a second signal amplitude sequence of each position in a second horizontal scanning direction in the two-dimensional scanning plane is sequentially obtained, and the second signal amplitude sequence is arranged according to the positions of the first horizontal scanning direction and the sampling time sequence in the signal flight direction to form an ultrasonic D-scan image section perpendicular to the B-scan image section. A third signal amplitude sequence at the same sampling time sequence in the signal flight direction is arranged according to the scanning positions to form an ultrasonic C-scan image section.

8. An ultrasound phase correction scan imaging system based on interface peak searching, characterized by, It comprises an ultrasonic probe, a processor and a display, The ultrasonic probe is used to send ultrasonic waves to the measured object. The processor is used to receive ultrasonic signals corresponding to the ultrasonic waves, perform phase correction on the ultrasonic signals by using the method according to any one of claims 1-7, and generate an ultrasonic image of the measured object. The display is used to display the ultrasonic image.

9. An ultrasound phase correction scan imaging apparatus based on interface peak searching, characterized by, It comprises: A processor; A memory, the memory has computer readable instructions stored thereon, when the computer readable instructions are executed by the processor, the method according to any one of claims 1-7 is realized.

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