A phased array full-focus-nonlinear fusion imaging method

Abstract

The present application relates to the field of nondestructive testing, in particular to a phased array full focus-nonlinear fusion imaging method, comprising the following steps: S1, determining a to-be-detected point of a detection object, performing full matrix data acquisition at the to-be-detected point by an ultrasonic phased array detection device, and performing full focus imaging on the collected data; S2, at the to-be-detected point, performing parallel emission and sequential emission twice respectively by the ultrasonic phased array detection device, and calculating a nonlinear image index; S3, performing data fusion on the normalized full focus imaging and the nonlinear image index to obtain a fusion image. The present application can obtain accurate profile features of micro defects and perform quantitative analysis, and can effectively evaluate the size of micro defect cracks.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of nondestructive testing, and particularly relates to a phased array full-focus-nonlinear fusion imaging method. BACKGROUND

[0002] Common mechanical structures in industry, such as moving equipment and static equipment coupled with the moving equipment, are prone to cracks due to the action of alternating stress. The propagation of micro-cracks is a process from slow to fast, and therefore, it is necessary to detect the micro-cracks in the equipment as early as possible through nondestructive testing means to avoid the rapid expansion of the micro-cracks and cause hidden dangers to the safe operation of the equipment. Micro-cracks are a form of early damage to materials, and through conventional detection means, the micro-cracks are prone to be missed or misdetected. Acoustic nonlinearity has a certain sensitivity to early damage to materials, and therefore, the nonlinearity ultrasonic detection technology can be used for analysis.

[0003] With the improvement of computer image processing capability, the ultrasonic phased array full-focus technology has obtained more and more attention in industrial applications. Compared with the traditional ultrasonic, the ultrasonic phased array technology adopts multi-channel, multi-chip transmission and reception, has a larger detection range, and has strong single-point imaging capability, and has certain advantages in micro-defect detection and contour recognition. When the ultrasonic phased array technology is used for micro-defect contour detection, the weak contact interface before crack propagation has weak linear acoustic response, and the accurate contour features of the micro-defects cannot be obtained for quantitative analysis, and the micro-defect crack size cannot be effectively evaluated in practice, and therefore, it is urgent to be solved. SUMMARY

[0004] In order to avoid and overcome the technical problems existing in the prior art, the present application provides a phased array full-focus-nonlinear fusion imaging method. The present application can obtain accurate contour features of micro-defects for quantitative analysis, and can effectively evaluate the micro-defect crack size in practice.

[0005] To achieve the above object, the present application provides the following technical scheme:

[0006] A phased array full-focus-nonlinear fusion imaging method comprises the following steps:

[0007] S1, determining a to-be-detected point of a detection object, performing full-matrix data acquisition at the to-be-detected point by an ultrasonic phased array detection device, and performing full-focus imaging on the collected data;

[0008] S2, at the to-be-detected point, performing parallel transmission and sequential transmission twice respectively by the ultrasonic phased array detection device, and calculating a nonlinear image index;

[0009] S3, data fusion of the normalized full-focus imaging and the nonlinear image index to obtain a fusion image.

[0010] As a further scheme of the present application: in step S2, each array element collectively excites signals according to a delay rule when transmitting in parallel, and receives signals synchronously, and the obtained signal set is matched and superimposed according to the delay rule and is subjected to Gaussian filtering, and then Fourier transform is performed to obtain the frequency domain parallel transmission signal P(x, y);

[0011] When transmitting sequentially, each array element of the ultrasonic phased array detection device transmits sequentially one by one, the transmission signal of each array element is received by all array elements to obtain a full matrix signal, the obtained signal set is subjected to imaging point synthesis focusing and Gaussian filtering, and then Fourier transform is performed to obtain the frequency domain sequential transmission signal Q(x, y);

[0012] Inverse Fourier transform is performed on the frequency domain parallel transmission signal P(x, y) and the frequency domain sequential transmission signal Q(x, y) to obtain a parallel time domain synthesis signal set d(x, y) and a sequential time domain synthesis signal set q(x, y);

[0013] The nonlinear image index is: κ(x, y) = |q(x, y) - d(x, y)|.

[0014] As a further scheme of the present application: the frequency domain parallel transmission signal can be expressed as:

[0015]

[0016] Wherein, N is the total number of array elements of the ultrasonic phased array detection device array probe;

[0017] a i (x, y) represents the sound beam phase of the receiving array element i at the point (x, y);

[0018] F i (t i (x, y)) is the analytical signal of the sound wave reflected by the point (x, y) received by the receiving array element i;

[0019] t i (x, y) is the shortest path time of the sound wave from the point (x, y) to the receiving array element i;

[0020] is the Fourier transform form of F i .

[0021] As a further scheme of the present application: the frequency domain sequential transmission signal can be expressed as:

[0022]

[0023] Wherein a ij (x, y) represents the sound beam phase of the transmitting array element i and the receiving array element j at the point (x, y);

[0024] F ij (t ij (x,y)) is the analytical signal of the sound wave emitted by the transmitting element i reflected at the point (x, y) and then received by the receiving element j;

[0025] t ij (x, y) represents the shortest path time of the sound beam emitted from the transmitting element i reflected at the point (x, y) and then received by the receiving element j;

[0026] is the Fourier transform form of F ij .

[0027] As a further scheme of the present application: in step S3, the full-focus-nonlinear fused image T(x, y) is:

[0028] T(x, y) = κ norm (x, y) + I norm (x, y)

[0029] wherein I norm (x, y) is the normalized value of the full-focus amplitude I(x, y) at the point (x, y);

[0030] κ norm (x, y) is the normalized value of the nonlinear image index κ(x, y) at the point (x, y).

[0031] As a further scheme of the present application: in step S1, the full-focus imaging formula is:

[0032]

[0033] I(x, y) is the full-focus amplitude of the imaging point (x, y);

[0034] F ij (t ij (x, y)) represents the analytical signal of the sound wave emitted by the transmitting element i reflected at the point (x, y) and then received by the receiving element j;

[0035] t ij (x, y) represents the shortest path time of the sound beam emitted from the transmitting element i reflected at the point (x, y) and then received by the receiving element j.

[0036] An electronic device, characterized by comprising a processor, an input device, an output device and a memory, the processor, the input device, the output device and the memory are connected in sequence, the memory is used to store a computer program, the computer program comprises program instructions, the processor is configured to call the program instructions, and the phased array full-focus-nonlinear fusion imaging method is executed.

[0037] A readable storage medium characterized in that the storage medium stores a computer program, the computer program comprising program instructions, the program instructions causing a processor to execute the phased array full-focus-nonlinear fusion imaging method when executed by the processor.

[0038] Compared with the prior art, the beneficial effects of the present application are:

[0039] 1. The present application quantifies and analyzes early micro-defects in the material by using linear imaging and nonlinear imaging respectively. Full-focus linear imaging can effectively present the defect profile and topographic features, and the nonlinear image index can show the features of the weak connection at the tip of the defect. The fusion imaging of linear imaging and nonlinear imaging is suitable for quantitative detection and monitoring of early micro-defect damage. The detection accuracy for closed or semi-closed defects reaches the micron level, accurate profile features of micro-defects can be obtained and quantitative analysis can be performed, and the size of micro-defect cracks can be effectively evaluated.

[0040] 2. The nonlinear image index of the present application considers the influence of nonlinear noise such as hardware system, material and coupling, adopts noise reduction measures of phase and amplitude compensation coefficients, and improves the measurement accuracy. The fusion imaging method combines the advantages of full-focus and nonlinear imaging, and the relative error of fusion imaging is smaller than that of full-focus and nonlinear imaging. The judgment of micro-defect size is more accurate, and the profile imaging of crack defects is closer to the real situation.

[0041] 3. The phased array detection device of the present application performs physical focusing and synthetic focusing respectively, and the difference between the two can reflect the nonlinear index of the detection object. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 It is a full-focus-nonlinear fusion imaging graph of micro-cracks of the present application.

[0043] Figure 2 It is a full-focus-nonlinear fusion imaging length measurement graph of micro-cracks of the present application.

[0044] Figure 3 It is a linear phased array full-focus imaging graph of micro-cracks of the present application.

[0045] Figure 4 It is a phased array full-focus imaging length measurement graph of micro-cracks of the present application.

[0046] Figure 5 It is a nonlinear imaging graph of micro-cracks of the present application.

[0047] Figure 6 It is a nonlinear imaging length measurement graph of micro-cracks of the present application. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0049] Please refer to Figures 1-6 In the embodiments of the present application, a phased array full-focusing-nonlinear fusion imaging method comprises the following steps:

[0050] S1, determining a to-be-detected point of a detection object, performing full-matrix data acquisition at the to-be-detected point by an ultrasonic phased array detection device, and performing full-focusing imaging on the collected data;

[0051] The detection object in the present application is a micro crack generated on a hanging piece inside a certain hydrogenation reactor. The actual length of the micro crack is 11.5 mm, which can be measured by micro forming of the micro crack, and this value can be used as a standard for evaluating the advantages and disadvantages of various defect imaging methods.

[0052] The ultrasonic phased array detection device used in the test comprises: a 64-element ultrasonic probe (element center distance: 0.60 mm; nominal center frequency: 5 MHz), a Micropulse FMC phased array controller, a computer with a phased array detection platform operating environment, and the like.

[0053] During detection, parameters such as sampling frequency, pulse width, pulse voltage, signal interval length and starting point, gain of the controller are set. The array probe is completely coupled with the surface of the sample through a coupling agent. Then, full-matrix data is collected by the phased array detection platform for full-focusing post-processing.

[0054] The full-focusing formula is:

[0055]

[0056] Wherein, N is the total number of array elements of the array probe of the ultrasonic phased array detection device;

[0057] I(x,y) is the full-focusing amplitude of the imaging point (x,y);

[0058] F ij (t ij (x,y)) represents an analytical signal that the sound wave emitted by the transmitting element i is reflected by the point (x,y) and then received by the receiving element j;

[0059] t ij(x, y) represents the shortest path time of the sound beam from the transmitting element i, reflecting at point (x, y), and then being received by the receiving element j.

[0060] S2, at the point to be detected, parallel transmission and sequential transmission are realized respectively by the ultrasonic phased array detection device twice, and a nonlinear image index is calculated. The phased array detection device performs physical focusing and synthetic focusing respectively, and the difference between the two can reflect the nonlinear index of the detection object.

[0061] Parallel transmission adopts a physical focusing method, which only considers the signals received by the array elements, so its signal only needs to be represented by the receiving array elements; sequential transmission adopts post-processing synthetic focusing, which considers both the transmitting array elements and the receiving array elements.

[0062] In parallel transmission, each array element collectively excites signals according to the delay rule and synchronously receives signals. The obtained signal set is matched and superimposed according to the delay rule and Gaussian filtering, and then Fourier transform is performed to obtain the frequency domain parallel transmission signal P(x, y);

[0063]

[0064] wherein N is the total number of array elements of the ultrasonic phased array detection device array probe;

[0065] a i (x, y) represents the phase of the sound beam at point (x, y) of the receiving array element i;

[0066] F i (t i (x, y)) is the analytical signal of the sound wave reflected at point (x, y) received by the receiving array element i;

[0067] t i (x, y) is the shortest path time of the sound wave from point (x, y) to the receiving array element i;

[0068] is the Fourier transform form of F i .

[0069] In sequential transmission, each array element of the ultrasonic phased array detection device transmits one by one in sequence, and the transmitting signal of each array element is received by all array elements to obtain a full matrix signal. The obtained signal set is subjected to imaging point synthetic focusing and Gaussian filtering, and then Fourier transform is performed to obtain the frequency domain sequential transmission signal Q(x, y).

[0070]

[0071] wherein a ij (x, y) represents the phase of the sound beam at point (x, y) of the transmitting array element i and the receiving array element j;

[0072] F ij (t ij (x,y)) is the analytic signal of the sound wave emitted by the transmitting element i, reflected at the point (x, y) and then received by the receiving element j;

[0073] t ij (x,y) represents the shortest path time of the sound beam emitted from the transmitting element i, reflected at the point (x, y) and then received by the receiving element j;

[0074] is the Fourier transform form of F ij .

[0075] Inverse Fourier transform is performed on the frequency domain parallel transmitting signal P(x, y) and the frequency domain sequential transmitting signal Q(x, y) to obtain the parallel time domain synthetic signal set d(x, y) and the sequential time domain synthetic signal set q(x, y);

[0076] The nonlinear image index is: κ(x, y) = |q(x, y) - d(x, y)|.

[0077] The Gaussian filtering expression for the one-dimensional signal set is:

[0078]

[0079] wherein I'(t) represents the value of the signal after Gaussian filtering at time t;

[0080] G(t-k) represents the value of the Gaussian function at position t-k;

[0081] I(k) represents the value of the original signal at position k.

[0082] S3, data fusion is performed on the normalized full-focus imaging and the nonlinear image index.

[0083] The full-focus-nonlinear image T(x, y) after data fusion is:

[0084] T(x, y) = κ norm (x, y) + I norm (x, y)

[0085] wherein I norm (x, y) is the normalized value of the full-focus amplitude I(x, y) at the point (x, y);

[0086] κ norm (x, y) is the normalized value of the nonlinear image index κ(x, y) at the point (x, y).

[0087] As Figure 3As shown, this is a linear full-focus imaging (I(x,y)) of microcracks in the hydrogenation reactor feedstock. It can be seen that the defect contours are clearly displayed.

[0088] like Figure 4 The image shows a -6 dB defect size measurement using full-focus imaging of microcracks in a hydrogenation reactor substrate. The measured microcrack length is 10.0 mm, and the relative error between the measured result and the microscopic measurement result is [missing value].

[0089] like Figure 5 As shown, the microcrack imaging κ(x,y) obtained by the nonlinear method can be seen. It can be seen that the crack tip is clearly displayed, indicating that nonlinear imaging is more sensitive to this part.

[0090] like Figure 6 The image shows a -6 dB defect size measurement using nonlinear imaging of microcracks in a hydrogenation reactor substrate. The measured microcrack length is 11.8 mm, and the relative error between the measured and microscopic results is [missing value].

[0091] like Figure 1 As shown, the microcrack full-focus-nonlinear imaging T(x,y) obtained by the fusion method is clearly displayed. It can be seen that the overall outline and tip of the crack are clearly displayed, indicating that the fusion imaging method combines the advantages of both full-focus and nonlinear imaging methods.

[0092] like Figure 2 The image shows a -6 dB defect size measurement of a microcrack in a hydrogenation reactor substrate using full-focusing nonlinear imaging. The measured microcrack length was 11.7 mm, with a relative error of [missing value] compared to the microscopic measurement result. Compared to full-focus and nonlinear imaging, fusion imaging has a smaller relative error, more accurate judgment of micro-defect size, and a more realistic imaging of crack defect contours.

[0093] Another embodiment of this application is an electronic device.

[0094] The electronic device can be the mobile device itself, or a standalone device that can communicate with the mobile device to receive the collected input signals from it and send the selected target decision behavior to it.

[0095] Electronic devices include one or more processors and memory.

[0096] A processor can be a central processing unit (CPU) or other form of processing unit with data processing and / or instruction execution capabilities, and can control other components in an electronic device to perform desired functions.

[0097] The memory can include one or more computer program products that can include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory, for example, can include random access memory (RAM), and / or a cache, etc. The non-volatile memory, for example, can include read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions can be stored on the computer-readable storage media, and the processor can execute the program instructions to implement the full-focus-nonlinear fusion imaging method of various embodiments of the present application described above.

[0098] In one example, the electronic device can further include an input device and an output device, which are interconnected through a bus system and / or other forms of connection mechanisms. For example, the input device can include various devices such as an on-board diagnostic system (OBD), a camera, an industrial camera, etc. The input device can also include, for example, a keyboard, a mouse, etc. The output device can include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto, etc.

[0099] In addition, the electronic device can further include any other appropriate components according to specific application cases.

[0100] Yet another embodiment of the present application is a computer program product that can also include computer program instructions that, when executed by a processor, cause the processor to perform the full-focus-nonlinear fusion imaging method steps described in the full-focus-nonlinear fusion imaging method section of the present specification according to various embodiments of the present application.

[0101] The computer program product can be written in any combination of one or more programming languages, including an object-oriented programming language such as Java, C++, etc., and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device or entirely on the remote computing device or server.

[0102] In addition, the embodiments of the present application can also be a computer-readable storage medium having stored thereon computer program instructions that, when executed by a processor, cause the processor to perform the full-focus-nonlinear fusion imaging method described in the present specification.

[0103] The computer readable storage medium can be embodied as one or more combinations of a readable medium and a readable medium can be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium include an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0104] The above description of the application is described with specific embodiments, but it should be pointed out that the advantages, advantages, effects mentioned in the application are only examples and not limitations, and these advantages, advantages, effects cannot be considered as the necessary possession of each embodiment of the application. In addition, the above specific details disclosed are only for the purpose of example and understanding, and not limited to the above specific details, which are not limited to the above specific details.

[0105] The block diagram of the device, apparatus, equipment, system involved in the application is only an illustrative example and is not intended to require or imply the connection, arrangement, configuration shown in the block diagram. As those skilled in the art will recognize, these devices, apparatus, equipment, system can be connected, arranged, configured in any way. Words such as "include", "contain", "have" and the like are open-ended words, which mean "including but not limited to", and can be used interchangeably. The words "or" and "and" used herein mean the word "and / or", and can be used interchangeably unless the context clearly indicates otherwise. The word "such as" used herein means the phrase "such as but not limited to", and can be used interchangeably.

[0106] It should also be noted that in the device, equipment and method of the application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombination should be considered as equivalent solutions of the application.

[0107] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects without departing from the scope of the application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0108] The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the application to the forms disclosed herein. Although various example aspects and embodiments have been discussed above, those of ordinary skill in the art will appreciate a variety of modifications, alternatives, permutations, additions, and sub-combinations of the described aspects and embodiments.

Claims

1. A phased array all-in-focus-nonlinear fusion imaging method, characterized in that, The method comprises the following steps: S1, determining a detection point of a detection object, performing full-matrix data acquisition at the detection point by an ultrasonic phased array detection device, and performing full-focus imaging on the collected data; S2, at the detection point, performing parallel transmission and sequential transmission twice respectively by the ultrasonic phased array detection device, and calculating a nonlinear image index; S3, performing data fusion on the normalized full-focus imaging and the nonlinear image index to obtain a fusion image.

2. The phased array full focusing-nonlinear fusion imaging method according to claim 1, characterized in that, In step S2, in parallel transmission, each array element collectively excites a signal according to a delay rule, and synchronously receives a signal, a signal set obtained is matched and superimposed according to the delay rule and Gaussian filtering is performed, and then Fourier transform is performed to obtain a frequency domain parallel transmission signal Px,y; In sequential transmission, each array element of the ultrasonic phased array detection device transmits sequentially, the transmission signal of each array element is received by all array elements to obtain a full-matrix signal, imaging point synthesis focusing and Gaussian filtering are performed on the obtained signal set, and then Fourier transform is performed to obtain a frequency domain sequential transmission signal Qx,y; Inverse Fourier transform is performed on the frequency domain parallel transmission signal Px,y and the frequency domain sequential transmission signal Qx,y to obtain a parallel time domain synthesis signal set dx,y and a sequential time domain synthesis signal set qx,y; The nonlinear image index is κx,y = qx,y-dx,y.

3. The phased array full focusing-nonlinear fusion imaging method of claim 2, wherein, The frequency domain parallel transmission signal can be expressed as: Wherein, N is the total number of array elements of the ultrasonic phased array detection device array probe; a i (x,y) denotes the acoustic beam phase at point (x,y) for receive element i; F i (t i (x,y)) is the analytic signal received by the receiving element i of the reflected sound wave by the point x, y; t i (x,y) is the shortest path time for the acoustic wave from point x,y to receiving element i; F i Fourier transform form.

4. The phased array full focusing-nonlinear fusion imaging method of claim 2, wherein, The frequency domain sequential transmission signal can be expressed as: where a ij (x,y) represents the acoustic beam phase at point (x,y) for transmit element i and receive element j; F ij (t ij (x,y)) is the analytic signal of the sound wave emitted by the transmitting element i, reflected at the point x, y and then received by the receiving element j; t ij (x,y) represents the shortest path time for a sound beam to be transmitted from a transmitting element i, reflected at a point x,y, and then received by a receiving element j; F ij Fourier transform form.

5. The phased array full focusing-nonlinear fusion imaging method according to any one of claims 1-4, characterized in that, In step S3, the full-focus-nonlinear image Tx,y after data fusion is: Tx,y= K norm x,y+I norm (x,y) where I norm (x,y) is the normalized value of the full focus amplitude Ix,y at point x, y; Kappa norm x,y is the normalized value of the non-linear image metric Kappa x,y at point x,y.

6. The phased array full focusing-nonlinear fusion imaging method according to any one of claims 1-4, characterized in that, In step S1, the full-focus imaging formula is: Ix,y is the full-focus amplitude of the imaging point x,y; F ij (t ij (x,y)) represents the analytic signal of the sound wave emitted by the transmitting element i, reflected at the point x, y and then received by the receiving element j; t ij (x,y) represents the shortest path time for a sound beam to be transmitted from a transmitting element i, reflected off a point x,y, and then received by a receiving element j.

7. An electronic device, comprising: The processor, the input device, the output device and the memory are connected in sequence, the memory is used for storing a computer program, the computer program comprises program instructions, the processor is configured to invoke the program instructions, and the phased array full-focus-nonlinear fusion imaging method in any one of claims 1-4 is executed.

8. A readable storage medium, characterized by, The storage medium stores a computer program, the computer program comprises program instructions, and the program instructions enable the processor to execute the phased array full-focus-nonlinear fusion imaging method in any one of claims 1-4 when the processor executes the program instructions.

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