Ultrasonic longitudinal wave normal probe acoustic beam diameter measuring method and device

Abstract

The invention belongs to the field of nondestructive testing, and relates to an ultrasonic longitudinal wave normal probe acoustic beam diameter measuring method and device. The method comprises the following steps: firstly, defining and determining a final sound pressure maximum plane water distance, determining detection sensitivity, carrying out super-resolution reconstruction on ultrasonic C scanning image data of a final sound pressure maximum plane to obtain richer array data, then, carrying out mean filtering, extracting a sound beam diameter contour array of sensitivity attenuation in the array, and finally, carrying out super-resolution reconstruction on the sound beam diameter contour array. And finally, fitting the acoustic beam diameter contour array, and calculating the maximum diameter and the minimum diameter of the probe acoustic beam by using the acoustic beam contour and the sampling interval. According to the method, the problem that the ultrasonic longitudinal wave normal probe acoustic beam diameter is difficult to accurately quantify and evaluate is solved, the ultrasonic detection and the computer vision are combined, the ultrasonic longitudinal wave normal probe acoustic beam diameter is evaluated, and the reliability of ultrasonic detection is effectively guaranteed.

Description

Technical Field

[0001] The invention relates to a method and a device for measuring the diameter of an ultrasonic longitudinal wave straight probe sound beam, and belongs to the field of non-destructive testing. Background Art

[0002] In recent years, with the continuous improvement of non-destructive evaluation requirements in the field of aero-engine manufacturing, in order to ensure the quality stability of ultrasonic non-destructive testing, more stringent requirements have been put forward for the sound beam characteristics of the ultrasonic longitudinal wave straight probe used. The sound beam characteristics of the ultrasonic longitudinal wave straight probe directly affect the reliability of the ultrasonic non-destructive testing results. The method of measuring the beam diameter at interval angles used in the existing technology is difficult to ensure accuracy and cannot truly measure the maximum and minimum diameters of the focal sound beam. Instead, it only randomly measures the sound beam diameters in a pair of orthogonal directions at the focal position. This result cannot accurately evaluate the sound beam characteristics of the ultrasonic probe. Therefore, a quantitative method is needed to accurately measure the sound beam characteristics of the ultrasonic longitudinal wave straight probe. Summary of the invention

[0003] The purpose of the present invention is: to solve this problem, the present invention proposes a method for measuring the sound beam diameter of an ultrasonic longitudinal wave straight probe, which can realize the identification of the sound beam profile of the final sound pressure maximum plane of the ultrasonic longitudinal wave straight probe, extract the true maximum and minimum sound beam diameter sizes at the probe focal position, and can quantitatively evaluate the sound beam profile, effectively improve the accuracy and reliability of the quality evaluation of the ultrasonic longitudinal wave straight probe, and has great practical application prospects.

[0004] To solve this technical problem, the technical solution of the present invention is:

[0005] On the one hand, a method for measuring the diameter of an ultrasonic longitudinal wave straight probe sound beam is provided, and the steps are as follows:

[0006] S1: Determination of the final maximum sound pressure plane water distance and detection sensitivity:

[0007] Use the ultrasonic C-scan detection system and the ultrasonic longitudinal wave straight probe required for testing, adjust the detection sensitivity, transform the water distance along the straight line of the center point of the metal ball to form a distance-amplitude ultrasonic scanning image, and locate the position of the final maximum sound pressure plane;

[0008] The final maximum sound pressure plane water distance refers to the water distance corresponding to the last maximum amplitude point generated by the metal ball when the distance between the probe and the metal ball continues to increase; the water distance refers to the distance between the probe and the metal ball in the water;

[0009] S2: Final maximum sound pressure plane ultrasound C scan;

[0010] S3: Calculate the probe beam diameter using the C-scan test results.

[0011] The detection sensitivity in S1 meets the requirement that the maximum amplitude of the ultrasonic reflection signal of the metal ball is As%.

[0012] The final sound pressure maximum plane water distance is located by calculation using the distance-amplitude ultrasonic scanning image.

[0013] The step S3 is specifically as follows:

[0014] S301: converting the ultrasonic C-scan image of the final sound pressure maximum plane into two-dimensional array data M0;

[0015] S302: Performing super-resolution reconstruction on the two-dimensional array data M0 by spatial symmetric difference to obtain two-dimensional array data M1;

[0016] S303: Perform mean filtering on the two-dimensional array data M1 to obtain a two-dimensional array M2;

[0017] S304: extracting the sound beam diameter profile array C of the sensitivity attenuation S in the array M2;

[0018] S305: Fit each point of the beam diameter profile array C into an ellipse, which is the beam profile of the final maximum sound pressure plane; calculate the maximum diameter and minimum diameter of the probe beam using the beam profile and the sampling interval a to measure the probe beam size. Preferably, the fitting in step S305 is performed using the least squares method.

[0019] Specific process of step S2:

[0020] S201: Take the center of the metal ball as the scanning center and perform grid scanning parallel to the final maximum sound pressure plane;

[0021] S202: Record the ultrasonic C-scanning sampling interval a used for conversion between the image and the actual size.

[0022] In step S302, the size of any dimension in the two-dimensional array data M0 is at least doubled. The symmetric difference can make the size of the overall two-dimensional array data M0 at least quadruple, thus achieving super-resolution reconstruction.

[0023] Compared with the direct ultrasonic C-scanning sampling method, the reconstruction of super-resolution data is to improve the fitting accuracy in step S305. However, direct point scanning has the following defects: ① In order to achieve high resolution and fitting accuracy, the accuracy of the sampling points must be higher than the positioning accuracy of the equipment. ② Direct sampling is time-consuming and inefficient.

[0024] The specific operations of step S304 are as follows:

[0025] Extract the signal amplitude A corresponding to the sensitivity attenuation S in array M2. The amplitude calculation formula is:

[0026] A = round down [As × 10^(S / 20)]

[0027] Extract the position index corresponding to the element with value A in M2, and obtain the beam diameter profile array C = [c1, c2, ..., c n ](i=1,2,…,n), the value of n is the number of elements with value A in M2, c i is the position index corresponding to the i-th element.

[0028] The M0, M1, and M2 are all integer arrays. Compared with double and float data, int arrays can effectively extract the sound beam diameter profile.

[0029] On the other hand, an ultrasonic longitudinal wave straight probe sound beam diameter measuring device is provided, the device comprising: a probe, a motion function module, a regular reflector, an ultrasonic detector, and a liquid immersion tank, wherein the probe is connected to the motion function module and the ultrasonic detector, and the regular reflector is connected to the liquid immersion tank.

[0030] The motion function module drives the probe to perform grid scanning and records the scanning position coding information at the same time, and the ultrasonic detector extracts the ultrasonic signal amplitude. The regular reflector is a metal ball.

[0031] The beneficial effects of the present invention are:

[0032] The present invention solves the problem that it is difficult to quantify and evaluate the sound beam diameter of an ultrasonic longitudinal wave straight probe. By combining ultrasonic detection with computer vision, the sound beam diameter of an ultrasonic longitudinal wave straight probe is evaluated, thereby effectively ensuring the reliability of ultrasonic detection.

[0033] The method of the present invention sets the sampling interval and the sensitivity attenuation through the physical radius size of the probe sound beam, and sets the maximum and minimum values ​​of the search sound beam diameter through the sampling interval and the sensitivity attenuation, which can improve the search efficiency of the method for the sound beam diameter.

[0034] The method of the present invention utilizes spatial symmetric difference transformation to realize super-resolution reconstruction of the beam diameter scanning image, and then realizes extraction of the beam diameter profile and calculation of the beam diameter: spatial linear difference is performed in the horizontal and vertical directions of the two-dimensional array data of the ultrasonic C-scan image, and mean filtering is used to reduce the influence of noise signals. The beam diameter profile in the array is extracted using the sensitivity attenuation, and the profile is used to perform least squares calculation to obtain a profile fitting graph, thereby realizing calculation of the beam diameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions implemented in the present invention, the following is a brief explanation of the drawings required to be used in the examples of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 The figure shows the schematic diagram of the probe beam diameter evaluation process;

[0037] Figure 2 It is a schematic diagram of a distance-amplitude ultrasound scanning image;

[0038] Figure 3 This is the principle diagram of the ultrasonic longitudinal wave straight probe sound beam diameter measurement device; DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] The features of various aspects of the embodiments of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to fully understand the present invention. However, it is obvious to those skilled in the art that the present invention can also be implemented without these specific details. The following description of the embodiments is only for a better understanding of the present invention by illustrating examples of the present invention. The present invention is not limited to any specific settings and methods provided below, but covers all product structures, any improvements, replacements, etc. of methods covered without departing from the spirit of the present invention.

[0041] In the various drawings and the following description, well-known structures and techniques are not shown to avoid unnecessarily obscuring the present invention.

[0042] like Figure 1 The schematic diagram of the probe beam diameter measurement and evaluation process shown includes the determination of the final sound pressure maximum plane water distance and detection sensitivity; the final sound pressure maximum plane ultrasonic C-scan; and the use of C-scan detection results to realize the probe beam diameter evaluation.

[0043] The specific steps for measuring and evaluating the sound beam diameter of an ultrasonic longitudinal wave straight probe are as follows:

[0044] Step 1: Determination of the final maximum sound pressure plane water distance and detection sensitivity:

[0045] like Figure 3 The schematic diagram of the measuring device is shown, which includes: a probe 1, a regular reflector 2, a motion function module 3, an ultrasonic detector 4, and a liquid immersion tank 5; the regular reflector 1 is a metal ball. The metal ball is a regular reflector used to evaluate the diameter of the probe sound beam in the ultrasonic C-scan detection system.

[0046] Use the ultrasonic C-scan detection system and the ultrasonic longitudinal wave straight probe required for the test, adjust the detection sensitivity, and transform the water distance along the straight line passing the center point of the small diameter metal ball to form a distance-amplitude ultrasonic scanning image, such as Figure 2 As shown, the water distance corresponding to the dotted line is the water distance corresponding to the position of the final maximum sound pressure plane;

[0047] The ultrasonic probe is moved parallel to the plane of the maximum sound pressure value and the detection sensitivity is adjusted so that the maximum amplitude of the ultrasonic reflection signal of the small-diameter metal ball is 80%.

[0048] Step 2: Final maximum sound pressure plane ultrasonic C-scan, including:

[0049] Take the center of the small diameter metal ball as the scanning center and perform grid scanning parallel to the final maximum sound pressure plane;

[0050] The ultrasonic C-scan sampling interval used for recording was 0.05 mm, which was used for the conversion between the image and the actual size;

[0051] Step 3: Use the C-scan test results to evaluate the probe beam diameter, including:

[0052] The specific process is as follows:

[0053] Convert the ultrasonic C-scan image of the final sound pressure maximum plane into two-dimensional array data M0;

[0054] The two-dimensional array data M0 of size [m,m] is transformed into the two-dimensional array data M1 of size [5m,5m] by spatial symmetric difference, so that the size of the C-scan result is enlarged to 25 times, realizing super-resolution reconstruction;

[0055] The two-dimensional array data M1 is subjected to mean filtering using a filter of size [5, 5] to obtain a two-dimensional array M2;

[0056] Extract the signal amplitude A corresponding to the sensitivity attenuation S in array M2. The amplitude calculation formula is:

[0057] A=int(As×10^(S / 20))

[0058] Extract the position index corresponding to the element with value A in M2, and obtain the beam diameter profile array C = [c1, c2, ..., c n](i=1,2,…,n), the value of n is the number of elements with value A in M2, c i is the position index corresponding to the i-th element. Here, As is 80, which is consistent with the maximum amplitude value in step 1.

[0059] Among them, M0, M1, and M2 are all integer arrays (int type). Compared with double and float data, int arrays can effectively extract the sound beam diameter profile.

[0060] The least square method is used to fit each point of the beam diameter profile array C into an ellipse, which is the beam profile of the final maximum sound pressure plane. The major axis diameter of the profile obtained by fitting is Ra, and the minor axis diameter is Rb.

[0061] The maximum diameter of the probe beam is calculated to be 0.01*Ra mm and the minimum diameter is 0.01*Rb mm using the beam profile and a sampling interval of 0.05 mm.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A method for measuring the diameter of an ultrasonic longitudinal wave straight probe sound beam, characterized in that: The method steps are as follows: S1: Determination of the final maximum sound pressure plane water distance and detection sensitivity: Use the ultrasonic C-scan detection system and the ultrasonic longitudinal wave straight probe required for testing, adjust the detection sensitivity, transform the water distance along the straight line of the center point of the metal ball to form a distance-amplitude ultrasonic scanning image, and locate the position of the final maximum sound pressure plane; The final maximum sound pressure plane water distance refers to the water distance corresponding to the last maximum amplitude point generated by the metal ball when the distance between the probe and the metal ball continues to increase; S2: Final maximum sound pressure plane ultrasound C scan; S3: Calculate the probe beam diameter using the C-scan test results.

2. The method according to claim 1, characterized in that: The detection sensitivity meets the requirement that the maximum amplitude of the ultrasonic reflection signal of the metal ball is As%.

3. The method according to claim 1, characterized in that: The final sound pressure maximum plane water distance is located by calculation using the distance-amplitude ultrasonic scanning image.

4. The method according to claim 1, characterized in that: The step S3 is specifically as follows: S301: converting the ultrasonic C-scan image of the final sound pressure maximum plane into two-dimensional array data M0; S302: Performing super-resolution reconstruction on the two-dimensional array data M0 by spatial symmetric difference to obtain two-dimensional array data M1; S303: Perform mean filtering on the two-dimensional array data M1 to obtain a two-dimensional array M2; S304: extracting the sound beam diameter profile array C of the sensitivity attenuation S in the array M2; S305: Fit each point of the beam diameter profile array C into an ellipse, which is the beam profile of the final maximum sound pressure plane; calculate the maximum diameter and minimum diameter of the probe beam using the beam profile and the sampling interval a to achieve measurement of the probe beam size.

5. The method according to claim 1, characterized in that: Specific process of step S2: S201: Take the center of the metal ball as the scanning center and perform grid scanning parallel to the final maximum sound pressure plane; S202: Record the ultrasonic C-scanning sampling interval a used for conversion between the image and the actual size.

6. The method according to claim 1, characterized in that: In step S302, the size of any dimension in the two-dimensional array data M0 is at least doubled.

7. The method according to claim 1, characterized in that: The specific operations of step S304 are as follows: Extract the signal amplitude A corresponding to the sensitivity attenuation S in array M2. The amplitude calculation formula is: A = round down [As × 10^(S / 20)] Extract the position index corresponding to the element with value A in M2, and obtain the beam diameter profile array C = [c1, c2, ..., c n ](i=1,2,…,n), the value of n is the number of elements with value A in M2, c i is the position index corresponding to the i-th element.

8. The method according to claim 7, characterized in that: The M0, M1, and M2 are all integer arrays.

9. The method according to claim 4, characterized in that: The fitting in step S305 is performed using the least squares method.

10. An ultrasonic longitudinal wave straight probe sound beam diameter measuring device, according to the method of claim 1, characterized in that: The device comprises: a probe, a motion function module, a regular reflector, an ultrasonic detector, and a liquid immersion tank; wherein the probe is connected to the motion function module and the ultrasonic detector, and the regular reflector is connected to the liquid immersion tank; the motion function module drives the probe to perform grid scanning and simultaneously records scanning position coding information, and the ultrasonic detector extracts the ultrasonic signal amplitude.

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