A method and device for measuring the diameter of an ultrasonic longitudinal wave straight probe sound beam

Abstract

This invention belongs to the field of non-destructive testing and relates to a method and device for measuring the beam diameter of an ultrasonic longitudinal wave straight probe. The invention first defines and determines the water distance to the final sound pressure maximum plane and determines the detection sensitivity. The ultrasonic C-scan image data of the final sound pressure maximum plane is then reconstructed using super-resolution to obtain richer array data. Next, after mean filtering, the beam diameter profile array representing the sensitivity attenuation is extracted from the array. Finally, the beam diameter profile array is fitted, and the maximum and minimum diameters of the probe beam are calculated using the beam profile and sampling interval. This invention solves the problem of accurately quantifying and evaluating the beam diameter of an ultrasonic longitudinal wave straight probe by combining ultrasonic testing with computer vision, effectively ensuring the reliability of ultrasonic testing.

Description

Technical Field

[0001] This invention relates to a method and apparatus for measuring the beam diameter of an ultrasonic longitudinal wave straight probe, belonging to the field of nondestructive testing. Background Technology

[0002] In recent years, with the increasing demands for non-destructive testing (NDT) in the aero-engine manufacturing field, more stringent requirements have been placed on the acoustic beam characteristics of ultrasonic longitudinal wave straight probes to ensure the quality stability of ultrasonic NDT. The acoustic beam characteristics of the ultrasonic longitudinal wave straight probe directly affect the reliability of ultrasonic NDT results. Existing methods, such as measuring beam diameter at interval angles, are inaccurate and cannot accurately measure the maximum and minimum diameters of the focal beam. Instead, they only randomly measure the beam diameters in a pair of orthogonal directions at the focal position. This result cannot accurately evaluate the acoustic beam characteristics of the ultrasonic probe. Therefore, a quantitative method is needed to accurately measure the acoustic beam characteristics of the ultrasonic longitudinal wave straight probe. Summary of the Invention

[0003] The purpose of this invention is to address this problem by proposing a method for measuring the beam diameter of an ultrasonic longitudinal wave straight probe. This method enables the identification of the beam profile of the final plane with maximum sound pressure level of the ultrasonic longitudinal wave straight probe, extracts the true maximum and minimum beam diameter dimensions at the probe's focal position, and allows for quantitative evaluation of the beam profile. This effectively improves the accuracy and reliability of the quality evaluation of ultrasonic longitudinal wave straight probes and has great potential for practical application.

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

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

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

[0007] An ultrasonic C-scan detection system and the ultrasonic longitudinal wave straight probe to be tested are used. The detection sensitivity is adjusted and the water distance is changed linearly along the center point of the metal ball to form a distance-amplitude ultrasonic scan image, and the position of the plane with the maximum sound pressure is located.

[0008] The final maximum sound pressure plane distance refers to the water distance corresponding to the last maximum amplitude point produced by the metal ball as the distance between the probe and the metal ball continuously increases; the water distance refers to the distance between the probe and the metal ball in the water.

[0009] S2: Planar ultrasound C-scan with maximum final sound pressure level;

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

[0011] The detection sensitivity in S1 must meet the requirement that the maximum amplitude of the ultrasonic reflection signal from the metal sphere is As%.

[0012] The location of the final maximum sound pressure plane water distance is calculated using distance-amplitude ultrasonic scanning images.

[0013] Step S3 specifically involves:

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

[0015] S302: Reconstruct the two-dimensional array data M0 using spatial symmetric interpolation to obtain the two-dimensional array data M1;

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

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

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

[0019] Step S2 detailed process:

[0020] S201: Using the center of the metal sphere as the scanning center, perform a grid scan parallel to the final maximum sound pressure plane;

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

[0022] In step S302, the size of any dimension of the two-dimensional array data M0 is increased by at least one time. Symmetric interpolation can increase the size of the overall two-dimensional array data M0 by at least four times, achieving super-resolution reconstruction.

[0023] Compared to direct ultrasound C-scan sampling, super-resolution data reconstruction aims to improve the fitting accuracy in step S305. Direct sampling has the following drawbacks: ① To achieve high resolution and fitting accuracy, the sampling point accuracy must be higher than the device's positioning accuracy. ② Multiple direct sampling operations are time-consuming and inefficient.

[0024] The specific operation of step S304 is as follows:

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

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

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

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

[0029] On the other hand, an ultrasonic longitudinal wave straight probe beam diameter measuring device is provided. The device includes: a probe, a motion function module, a regular reflector, an ultrasonic detector, and a liquid immersion tank. 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 module drives the probe to perform grid scanning and simultaneously records the scanning position encoding information; the ultrasonic detector extracts the ultrasonic signal amplitude. The regular reflector is a metal sphere.

[0031] The beneficial effects of this invention are:

[0032] This invention solves the problem of the difficulty in quantitatively evaluating the beam diameter of ultrasonic longitudinal wave straight probes. By combining ultrasonic detection with computer vision, it achieves the evaluation of the beam diameter of ultrasonic longitudinal wave straight probes, effectively ensuring the reliability of ultrasonic detection.

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

[0034] This invention utilizes spatially symmetric interpolation transformation to achieve super-resolution reconstruction of acoustic beam diameter scan images, thereby enabling the extraction of the acoustic beam diameter profile and the calculation of the acoustic beam diameter. The method involves performing spatial linear interpolation in both the horizontal and vertical directions of a two-dimensional array of ultrasound C-scan images, and employing mean filtering to reduce the influence of noise signals. The acoustic beam diameter profile is extracted from the array using sensitivity attenuation, and a least-squares calculation is performed on the profile to obtain a fitted graph, thus enabling the calculation of the acoustic beam diameter. Attached Figure Description

[0035] To more clearly illustrate the technical solutions implemented in this invention, the accompanying drawings used in the embodiments of this invention will be briefly explained below. Obviously, the drawings described below are merely some embodiments of this invention. Those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0036] Figure 1 The diagram shown illustrates the process of evaluating the probe's acoustic beam diameter.

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

[0038] Figure 3 Schematic diagram of an ultrasonic longitudinal wave straight probe beam diameter measuring device; Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] The features of various aspects of the embodiments of the present invention will now be described in detail. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can also be practiced without these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by illustrating examples. The invention is not limited to any specific setups and methods provided below, but covers all improvements, substitutions, etc., to product structures and methods without departing from the spirit of the invention.

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

[0042] like Figure 1 The schematic diagram shown illustrates the process of measuring and evaluating the probe beam diameter, including determining the final water distance to the plane of maximum sound pressure and the detection sensitivity; ultrasonic C-scan of the final plane of maximum sound pressure; and evaluating the probe beam diameter using the C-scan detection results.

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

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

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

[0046] An ultrasonic C-scan detection system and the required ultrasonic longitudinal wave straight probe are used. The detection sensitivity is adjusted to change the water distance along a straight line from the center point of the small-diameter metal sphere to form a distance-amplitude ultrasonic scan image, such as... Figure 2 As shown, the water distance corresponding to the dashed line is the water distance corresponding to the location of the plane with the maximum sound pressure.

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

[0048] Step 2: Final ultrasound C-scan with maximum sound pressure level, including:

[0049] Using the center of a small-diameter metal sphere as the scanning center, a grid scan is performed parallel to the plane of maximum sound pressure.

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

[0051] Step 3: Utilize C-scan detection results to evaluate the probe's acoustic beam diameter, including:

[0052] The specific process is as follows:

[0053] The ultrasound C-scan image of the final sound pressure maximum plane is converted into two-dimensional array data M0;

[0054] The two-dimensional array data M0 of size [m,m] is transformed into two-dimensional array data M1 of size [5m,5m] through spatial symmetric interpolation, which increases the size of the C-scan result by 25 times and achieves super-resolution reconstruction;

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

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

[0057] A = int(As × 10^(S / 20))

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

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

[0060] The least squares 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 sound pressure maximum plane. The fitted profile has a major axis diameter of Ra and a minor axis diameter of Rb.

[0061] Using the acoustic beam profile and a sampling interval of 0.05 mm, the maximum diameter of the probe's acoustic beam is calculated to be 0.01*Ra mm and the minimum diameter is 0.01*Rb 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 person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A method for measuring the beam diameter of an ultrasonic longitudinal wave straight probe, characterized in that: The method steps are as follows: S1: Determination of the final maximum sound pressure level plane water distance and detection sensitivity: An ultrasonic C-scan detection system and the ultrasonic longitudinal wave straight probe to be tested are used. The detection sensitivity is adjusted and the water distance is changed linearly along the center point of the metal ball to form a distance-amplitude ultrasonic scan image, and the position of the plane with the maximum sound pressure is located. The final maximum sound pressure plane water distance refers to the water distance corresponding to the last maximum value of the amplitude generated by the metal ball as the distance between the probe and the metal ball increases continuously. The detection sensitivity requirement is to maximize the amplitude of the ultrasonic reflection signal from the metal sphere to As%. S2: Planar ultrasound C-scan with maximum final sound pressure level; specifically: S201: Using the center of the metal sphere as the scanning center, perform a grid scan parallel to the final maximum sound pressure plane; S202: Record the ultrasound C-scan sampling interval 'a' used for image-to-actual-size conversion. S3: Calculate the probe beam diameter using the C-scan detection results; specifically: S301: Convert the ultrasound C-scan image of the final sound pressure maximum plane into two-dimensional array data M0; S302: Reconstruct the two-dimensional array data M0 using spatial symmetric interpolation to obtain the two-dimensional array data M1; S303: Perform mean filtering on the two-dimensional array data M1 to obtain the two-dimensional array M2; S304: Extract the beam diameter profile array C of the sensitivity attenuation S in array M2; the specific operation is as follows: Extract the signal amplitude A corresponding to the sensitivity attenuation S in array M2. The amplitude calculation formula is as follows: A = rounded down [A × 10^(S / 20)] Extract the position index corresponding to the element with value A in M2 to obtain the beam diameter profile array C=[c1, c2, ..., c n (i=1,2,…,n), where n is the number of elements in M2 whose value is A, and c i This is the position index corresponding to the i-th element; S305: Fit each point of the beam diameter profile array C to an ellipse, which is the beam profile of the final sound pressure maximum plane; use the beam profile and sampling interval a to calculate the maximum and minimum diameter of the probe beam, and realize the measurement of the probe beam size.

2. The method according to claim 1, characterized in that: The location of the final maximum sound pressure plane water distance is calculated using distance-amplitude ultrasonic scanning images.

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

4. The method according to claim 1, characterized in that: M0, M1, and M2 are all integer arrays.

5. The method according to claim 1, characterized in that: The fitting in step S305 is performed using the least squares method.

6. An ultrasonic longitudinal wave straight probe beam diameter measuring device, as described in claim 1, characterized in that: The device includes: 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 the scanning position encoding information, and the ultrasonic detector extracts the ultrasonic signal amplitude.

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