Non-coaxial laser ultrasonic detection device and method

Abstract

The invention relates to a non-coaxial laser ultrasonic detection device and method, the non-coaxial laser ultrasonic detection device comprises a laser device, a detection table provided with a fixing frame and an industrial camera, the device further comprises a mounting assembly, the mounting assembly comprises a laser device mounting assembly and an industrial camera mounting assembly, the laser device is connected with the laser device mounting assembly, and the industrial camera mounting assembly is connected with the laser device mounting assembly. The industrial camera is connected with the industrial camera mounting assembly; the mounting assembly is placed on the detection table, and the positions of the laser and the industrial camera are changed by controlling the mounting assembly, so that non-coaxial arrangement is realized; according to the method, detection is completed in sequence by changing the position of the detection device. The laser and the industrial camera are not arranged on the same axis, and the relative position between the laser and the industrial camera is allowed to be flexibly set according to the requirement of a specific detection area, so that comprehensive detection of complex shapes and structures is realized; by arranging the adjusting screw rod, micron-sized adjustment is realized, and the accuracy and the stability of a detection result, especially the detection of a micron-sized structure, are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of elastic wave precision measurement, and in particular to a non-coaxial laser ultrasonic detection device and method. Background Art

[0002] In the field of waves, elastic waves are carriers of internal stress and strain transmission in materials, and their propagation characteristics directly reflect the mechanical properties, internal structure and dynamic response of the materials. By precisely controlling the excitation, propagation and attenuation processes of elastic waves (such as Rayleigh waves and Lamb waves), we can not only deeply understand the basic physical properties of materials, but also have many potential applications such as acoustic imaging, acoustic sensing, acoustic stealth, etc., and can also achieve material performance optimization, defect detection and positioning, real-time monitoring of structural health status, as well as vibration suppression and noise control. The development of efficient and flexible elastic wave control technology is of great significance to improving the quality and safety of industrial products, and is expected to play a key role in many fields such as materials science, mechanical engineering, aerospace, etc.

[0003] Accurate measurement and in-depth understanding of the propagation characteristics of elastic waves are the premise and basis for achieving effective elastic wave control. Traditional contact elastic wave detection technology directly contacts the surface of the object to be tested through the probe to obtain elastic wave signals. This method has high requirements on the surface flatness of the object to be tested and the detection speed is slow. Its application scope is relatively limited and the equipment cost is high. Laser ultrasonic testing, as a non-contact measurement technology, can detect the propagation process of ultrasonic waves through laser beams at a long distance, thereby obtaining detailed information of the object, which shows unique advantages.

[0004] The invention patent with the publication number CN115184462A discloses a laser ultrasonic detection system based on a combined non-contact probe, including: a laser, a laser scanning module, a combined non-contact probe and a computer. The laser beam emitted by the laser generates a laser ultrasonic signal on the object to be detected after passing through the laser scanning module, which is then received by the combined non-contact probe, and finally the signal defect analysis is performed on the computer. By rotating the substrate in the combined non-contact probe, the arrangement order between the microphone and the air coupling probe with different distances from the rotation center is adjusted, so that the combined non-contact probe is adapted to the objects to be detected with different thickness distributions, improving the efficiency of laser ultrasonic detection and increasing the accuracy of receiving laser ultrasonic signals. The invention has the following problems: the detection frequency range is limited, the applicability is not strong, and it is difficult to adapt to the detection requirements of different sizes, shapes and materials; the measurement accuracy needs to be improved, especially in the detection of micron-level structures, its stability and adaptability are poor, and it is easily affected by the environment; the device structure is complex, installation and debugging are difficult, and it is difficult to achieve rapid deployment and flexible application; the data processing capacity is limited, and it is difficult to achieve real-time data collection and processing, which affects the detection efficiency.

[0005] Therefore, it is an urgent problem to provide a laser ultrasonic detection device that can achieve a wide detection frequency range, can detect complex structures and has high detection accuracy. Summary of the invention

[0006] The purpose of the present invention is to provide a non-coaxial laser ultrasonic detection device and method in order to overcome the defects of the above-mentioned prior art.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] According to a first aspect of the present invention, there is provided a non-coaxial laser ultrasonic detection device, comprising a laser, a detection platform with a fixed frame, and an industrial camera, the device further comprising a mounting assembly, the mounting assembly comprising a laser mounting assembly and an industrial camera mounting assembly, the laser being connected to the laser mounting assembly, and the industrial camera being connected to the industrial camera mounting assembly; the mounting assembly being placed on the detection platform, and the positions of the laser and the industrial camera being changed by controlling the mounting assembly, thereby realizing a non-coaxial arrangement.

[0009] As a preferred technical solution, a computer is also included, which is connected to the laser and the industrial camera respectively, and is used to display the laser position in real time and collect and process laser ultrasonic signals.

[0010] As a preferred technical solution, the laser mounting assembly or industrial camera mounting assembly includes a rail base; the rail base is provided with a groove, one end of the groove passes through the rail base, and the other end forms a fixed wall with the edge of the rail base.

[0011] As a preferred technical solution, a threaded hole is provided on the fixed wall, and the threaded hole is coaxial with the groove.

[0012] As a preferred technical solution, the laser mounting assembly or industrial camera mounting assembly also includes a slider and an adjusting screw; the slider is located in the groove of the rail base, the adjusting screw is connected to the slider through a threaded hole, and the adjusting screw is coaxial with the groove of the rail base.

[0013] As a preferred technical solution, the sliding block and the groove fit together.

[0014] As a preferred technical solution, the laser mounting assembly or industrial camera mounting assembly also includes a support frame; one end of the support frame is connected to a slider, and the other end is connected to a laser or an industrial camera, and the movement of the laser or the industrial camera is controlled by adjusting the screw with a knob.

[0015] As a preferred technical solution, the support frame rotates around an axis and shrinks up and down.

[0016] As a preferred technical solution, the laser and the industrial camera are not located on the same axis.

[0017] According to another aspect of the present invention, a method for a non-coaxial laser ultrasonic detection device as described above is provided, wherein the detection process of the method comprises the following steps:

[0018] S1. Fix the test object on the fixed frame of the test bench;

[0019] S2. Place the industrial camera and its mounting components at appropriate positions on the test bench, connect the computer and display the real-time image of the test object, make a preliminary observation and position the test object, and divide several initial test areas;

[0020] S3, placing the laser and its mounting assembly at an appropriate position on the test bench, connecting the computer and displaying the image, and irradiating the laser beam on an initial point to be tested within any initial area to be tested;

[0021] S4, the computer collects the data of the initial test point;

[0022] S5. According to the real-time image displayed on the computer, the position of the laser is adjusted to aim at the next initial point to be measured until the data of all initial points to be measured in the initial area to be measured are collected;

[0023] S6. According to the real-time image displayed by the computer, the positions of the industrial camera and the laser are adjusted to collect data of the initial points to be measured in the next initial area to be measured, until the data of the initial points to be measured in all the initial areas to be measured are collected;

[0024] S7. Process and analyze the collected data through a computer and generate a measurement result report.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention can enhance the adaptability and flexibility of the detection device by arranging the laser and the industrial camera on different axes, and allow the relative position between the two to be flexibly set according to the needs of the specific detection area, thereby achieving comprehensive detection of complex shapes and structures.

[0027] 2. The present invention achieves micrometer-level adjustment by setting an adjusting screw, and ensures the accuracy and stability of the detection results by finely adjusting the laser beam position and the image range of the industrial camera, especially for the detection of micrometer-level structures.

[0028] 3. By setting up a laser and an industrial camera, the present invention can achieve accurate detection of elastic waves in a wide frequency range, cover a wider frequency range, and meet the detection needs of different materials and structures.

[0029] 4. The laser mounting assembly and industrial camera mounting assembly used in the present invention both include standardized components such as a support frame, a slider, a rail base and an adjusting screw. These components can be quickly assembled and disassembled according to actual application requirements, which simplifies the installation and debugging process of the device, reduces the difficulty of operation, and enables the detection device to be quickly deployed in different detection scenarios.

[0030] 5. The present invention integrates a high-performance computer, which can realize real-time collection, display and processing of detection data, ensuring that operators can obtain detection results immediately and make real-time adjustments as needed, thereby improving detection efficiency and providing strong support for subsequent data analysis and mining, which is helpful to deeply explore the internal structure information of materials or elastic wave propagation characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention;

[0032] Figure 2 A top view of the device structure of the present invention;

[0033] Figure 3 It is a schematic diagram of the connection of the device of the present invention;

[0034] Figure 4 It is a schematic structural diagram of a micron-sized silicon plate sample of the present invention;

[0035] Figure 5 A fine image of a local area of ​​a sample taken by the industrial camera of the present invention;

[0036] Figure 6 This is a time domain result diagram of the experiment of exciting Lamb waves of the present invention;

[0037] Figure 7 The experimental displacement distribution diagram of the excited Lamb wave of the present invention;

[0038] Figure 8 It is a schematic diagram of the detection process of the present invention.

[0039] 1. Object to be detected; 2. Laser; 3. Support frame; 4. Track base; 5. Slider; 6. Adjusting screw; 7. Groove; 8. Positioning wall; 9. Threaded hole; 11. Industrial camera; 12. Computer. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 creative work should fall within the scope of protection of the present invention.

[0041] The existing technology has the problems of limited detection frequency range and weak applicability, making it difficult to adapt to the detection needs of different sizes, shapes and materials; the measurement accuracy needs to be improved, especially in the detection of micron-level structures, its stability and adaptability are poor, and it is easily affected by environmental interference; the device structure is complex, installation and debugging are difficult, and it is difficult to achieve rapid deployment and flexible application; the data processing capability is limited, making it difficult to achieve real-time data collection and processing, affecting the detection efficiency.

[0042] The present invention can realize accurate detection of elastic waves in a wide frequency range by arranging a laser and an industrial camera, covering a wider frequency range and meeting the detection requirements of different materials and structures; an adjusting screw is arranged to realize micron-level adjustment, and the accuracy and stability of the detection result are ensured by finely adjusting the laser beam position and the image range of the industrial camera, especially for the detection of micron-level structures; the laser and the industrial camera are arranged not on the same axis, which can enhance the adaptability and flexibility of the detection device, and allow the relative position between the two to be flexibly set according to the requirements of the specific detection area, so as to realize comprehensive detection of complex shapes and structures; the adopted laser mounting assembly and industrial camera mounting assembly both include standardized components such as a support frame, a slider, a rail base and an adjusting screw, which can be quickly assembled and disassembled according to actual application requirements, simplifying the installation and debugging process of the device, reducing the difficulty of operation, and enabling the detection device to be quickly deployed in different detection scenarios; a high-performance computer is integrated to realize real-time collection, display and processing of detection data, ensuring that the operator can obtain the detection results immediately and make real-time adjustments as needed, thereby improving the detection efficiency, providing strong support for subsequent data analysis and mining, and facilitating in-depth mining of material internal structure information or elastic wave propagation characteristics.

[0043] Example 1

[0044] The structure of the present invention is as follows Figure 1-Figure 3 As shown, 1. A non-coaxial laser ultrasonic detection device includes a laser 2, a detection table with a fixed frame, and an industrial camera 11, the device also includes a mounting assembly, the mounting assembly includes a laser mounting assembly and an industrial camera mounting assembly, the laser 2 is connected to the laser mounting assembly, and the industrial camera 11 is connected to the industrial camera mounting assembly; the mounting assembly is placed on the detection table, and the positions of the laser 2 and the industrial camera 11 are changed by controlling the mounting assembly to achieve a non-coaxial arrangement.

[0045] The system also includes a computer 12, which is connected to the laser 2 and the industrial camera 11 respectively, and is used to display the laser position in real time and collect and process laser ultrasonic signals.

[0046] In this embodiment, the object to be detected 1 is placed on the detection table, the laser beam of the laser 2 is irradiated on the object to be detected 1, the industrial camera 11 amplifies the image of the detected object and captures the laser position, and the computer 12 processes the collected information. The mounting assembly is used for the directional movement of the laser 2 or the industrial camera 11. The laser mounting assembly fixes the laser 2 and adjusts the laser beam position, and the industrial camera mounting assembly amplifies the image of the detected object and captures the laser position.

[0047] In actual application, the size and material of laser mounting components and industrial camera mounting components are not necessarily the same, and the component configuration has a variety of combinations and installation methods. It can be selected according to specific working environment, detection object or accuracy requirements to ensure the reliability of the detection system, which can meet the detection of small precision devices or large industrial equipment.

[0048] The laser mounting assembly or industrial camera mounting assembly includes a rail base 4 ; the rail base 4 is provided with a groove 7 , one end of the groove 7 passes through the rail base 4 , and the other end forms a fixed wall 8 with the edge of the rail base 4 .

[0049] The fixing wall 8 is provided with a threaded hole 9 , and the threaded hole 9 is coaxial with the groove 7 .

[0050] The laser mounting assembly or industrial camera mounting assembly also includes a slider 5 and an adjusting screw 6; the slider 5 is located in a groove 7 of a rail base 4, the adjusting screw 6 is connected to the slider 5 via a threaded hole 9, and the adjusting screw 6 is coaxial with the groove 7 of the rail base 4.

[0051] The slider 5 and the groove 7 fit together.

[0052] The laser mounting assembly or industrial camera mounting assembly also includes a support frame 3; one end of the support frame 3 is connected to the slider 5, and the other end is connected to the laser 2 or the industrial camera 11, and the movement of the laser 2 or the industrial camera 11 is controlled by adjusting the screw 6 with a knob.

[0053] In this embodiment, the threaded hole 9 and the adjusting screw 6 are of the same size. The screw 6 is adjusted by turning the knob, and the length of the adjusting screw 6 in the groove 7 is increased or decreased, so that the slider 5 moves in the groove 7, thereby controlling the lateral movement of the laser 2 or the industrial camera 11. The adjusting screw 6 can produce axial micron-level displacement changes, directly moving the slider 5, the support frame 3 and the laser 2 left and right, and is used to adjust the position of the laser spot on the micron-level sample. The adjustment range is 1 to 20 microns. By selecting a suitable pitch of the adjusting screw 6, the axial movement distance of the laser 2 or the industrial camera 11 can be accurately achieved; the laser mounting assembly can also achieve micron-level movement of the laser spot by integrating a high-precision micro-displacement drive system, such as using a piezoelectric ceramic driver.

[0054] The support frame 3 rotates around the axis and shrinks up and down.

[0055] In this embodiment, the support frame 3 rotates around the axis and shrinks up and down, so that the laser 2 or the industrial camera 11 can rotate left and right or move up and down with the support frame 3. In actual application, the laser mounting assembly and the industrial camera mounting assembly can be flexibly configured to ensure diversified configuration according to specific needs, support 360° full-scale rotation, meet precise front and back, left and right, and up and down movement adjustment, cover a wide range of fields of view and operating angles, and thus provide multi-dimensional high-precision detection.

[0056] The laser 2 and the industrial camera 11 are not located on the same axis.

[0057] In this embodiment, by placing the mounting components in different positions, the laser 2 and the industrial camera 11 can rotate left and right and move up and down, so that the laser 2 and the industrial camera 11 are not arranged on the same axis. The relative positions of the two should be set according to the detection area. The laser 2 and the industrial camera 11 are set independently, which can flexibly adjust the position and angle to adapt to detection objects of different shapes and sizes, and avoid signal interference to ensure the accuracy of the detection results.

[0058] In this embodiment, the object to be detected 1 is a micrometer-scale silicon-based triangular prism phononic crystal plate, including a straight topological interface and a parallelogram topological interface, such as Figure 4 As shown, the left side of the straight topology interface uses a circular piezoelectric element to generate a multi-cycle pulse voltage signal with a center frequency of 1.841 MHz. The piezoelectric element is a cylindrical piezoelectric ceramic with a diameter of 5 mm, a thickness of 1 mm, and a material of PZT-5H. The polarization direction is along the thickness direction; the operating frequency of the piezoelectric element of this size can at least cover the range of 1 to 4 MHz. Figure 5 It shows the fine images of the local area of ​​the sample taken by the industrial camera, which can clearly reflect the real structure of the sample and accurately identify the position of the laser spot, facilitating detailed observation and measurement.

[0059] In this embodiment, when the center frequency of the excitation signal of the piezoelectric element is 1.841 MHz, a combined non-coaxial laser ultrasonic detection device and method are used to scan the silicon-based phononic crystal along the x-axis and y-axis at intervals of 641 microns to measure the displacement of several points.

[0060] Figure 6 The experimental results of elastic waves on straight topological boundaries clearly show the propagation characteristics of elastic waves under pulse excitation conditions. Obviously, along the straight topological interface, the stronger light spot in the range of 0 to 4 mm is the location of the excitation source, and elastic waves propagate in the range of 4 to 18 mm, and no reflected waves are observed. This shows that this technical solution can effectively detect continuous elastic wave propagation on straight topological boundaries, and its detection accuracy is sufficient to distinguish between the excitation source and the propagation path of the elastic wave. At the same time, the experimental results also verify the stability and effectiveness of this technical solution under high-frequency excitation.

[0061] Figure 7 The experimental results of the displacement field distribution of silicon-based phononic crystals at a frequency of 1.841 MHz after pulse signal excitation for 0.07 milliseconds. It can be seen that there are displacement distributions at both the hexagonal topological interface and the straight topological interface, which effectively excites the topological boundary state and clearly reflects the flow path of elastic wave energy in the silicon-based phononic crystal. There is no significant energy leakage in the non-topological interface region. In addition, due to critical coupling, there is almost no elastic wave propagation on the right side of the straight topological interface, such as Figure 7 The displacement on the straight interface to the right of the middle hexagonal interface is small. This shows that this technical solution can accurately control the topological boundary state in the micrometer-scale phononic crystal, realize the efficient guidance and localization of elastic wave energy, help to reveal the law of elastic wave propagation, and provide a solid experimental basis for applications in the fields of elastic wave control.

[0062] Example 2

[0063] The detection process is as follows Figure 8 As shown, a method for a non-coaxial laser ultrasonic detection device, the detection process of the method includes the following steps:

[0064] S1. Fix the test object on the fixed frame of the test bench;

[0065] S2. Place the industrial camera and its mounting components at appropriate positions on the test bench, connect the computer and display the real-time image of the test object, make a preliminary observation and position the test object, and divide several initial test areas;

[0066] S3, placing the laser and its mounting assembly at an appropriate position on the test bench, connecting the computer and displaying the image, and irradiating the laser beam on an initial point to be tested within any initial area to be tested;

[0067] S4, the computer collects the data of the initial test point;

[0068] S5. According to the real-time image displayed on the computer, the position of the laser is adjusted to aim at the next initial point to be measured until the data of all initial points to be measured in the initial area to be measured are collected;

[0069] S6. According to the real-time image displayed by the computer, the positions of the industrial camera and the laser are adjusted to collect data of the initial points to be measured in the next initial area to be measured, until the data of the initial points to be measured in all the initial areas to be measured are collected;

[0070] S7. Process and analyze the collected data through a computer and generate a measurement result report.

[0071] In this embodiment, the measurement result report includes a displacement distribution diagram or other forms of reports.

[0072] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A non-coaxial laser ultrasonic detection device, comprising a laser (2), a detection table with a fixed frame, and an industrial camera (11), characterized in that: The device further comprises a mounting assembly, wherein the mounting assembly comprises a laser mounting assembly and an industrial camera mounting assembly, wherein the laser (2) is connected to the laser mounting assembly, and the industrial camera (11) is connected to the industrial camera mounting assembly; the mounting assembly is placed on a testing table, and the positions of the laser (2) and the industrial camera (11) are changed by controlling the mounting assembly, thereby achieving a non-coaxial arrangement.

2. A non-coaxial laser ultrasonic detection device according to claim 1, characterized in that: The invention also comprises a computer (12), which is connected to the laser (2) and the industrial camera (11) respectively and is used for displaying the laser position in real time and collecting and processing the laser ultrasonic signal.

3. The non-coaxial laser ultrasonic detection device according to claim 1, characterized in that: The laser mounting assembly or industrial camera mounting assembly comprises a rail base (4); the rail base (4) is provided with a groove (7), one end of the groove (7) passes through the rail base (4), and the other end forms a fixed wall (8) with the edge of the rail base (4).

4. A non-coaxial laser ultrasonic detection device according to claim 3, characterized in that: The fixed wall (8) is provided with a threaded hole (9), and the threaded hole (9) is coaxial with the groove (7).

5. The non-coaxial laser ultrasonic detection device according to claim 4, characterized in that: The laser mounting assembly or industrial camera mounting assembly further comprises a slider (5) and an adjusting screw (6); the slider (5) is located in a groove (7) of a rail base (4); the adjusting screw (6) is connected to the slider (5) via a threaded hole (9); and the adjusting screw (6) is coaxial with the groove (7) of the rail base (4).

6. The non-coaxial laser ultrasonic detection device according to claim 5, characterized in that: The slider (5) and the groove (7) fit together.

7. The non-coaxial laser ultrasonic detection device according to claim 6, characterized in that: The laser installation assembly or industrial camera installation assembly also includes a support frame (3); one end of the support frame (3) is connected to a slider (5), and the other end is connected to a laser (2) or an industrial camera (11); the movement of the laser (2) or the industrial camera (11) is controlled by adjusting the screw rod (6) with a knob.

8. The non-coaxial laser ultrasonic detection device according to claim 6, characterized in that: The support frame (3) rotates around the axis and shrinks up and down.

9. The non-coaxial laser ultrasonic detection device according to claim 1, characterized in that: The laser (2) and the industrial camera (11) are not located on the same axis.

10. A method for the non-coaxial laser ultrasonic detection device according to any one of claims 1 to 9, characterized in that: The detection process of the method comprises the following steps: S1. Fix the test object on the fixed frame of the test bench; S2. Place the industrial camera and its mounting components at appropriate positions on the test bench, connect the computer and display the real-time image of the test object, make a preliminary observation and position the test object, and divide several initial test areas; S3, placing the laser and its mounting assembly at an appropriate position on the test bench, connecting the computer and displaying the image, and irradiating the laser beam on an initial point to be tested within any initial area to be tested; S4, the computer collects the data of the initial test point; S5. According to the real-time image displayed on the computer, the position of the laser is adjusted to aim at the next initial point to be measured until the data of all initial points to be measured in the initial area to be measured are collected; S6. According to the real-time image displayed by the computer, the positions of the industrial camera and the laser are adjusted to collect data of the initial points to be measured in the next initial area to be measured, until the data of the initial points to be measured in all the initial areas to be measured are collected; S7. Process and analyze the collected data through a computer and generate a measurement result report.

Images