Flexible laser scattering detection device and operation method and application thereof

Abstract

The invention discloses a flexible laser scattering detection device and an operation method and application thereof, light output by a laser is converted into linearly polarized light, laser mobile scanning is controlled through a scanning galvanometer, so that a damaged area is accurately scanned, transmission of an image signal is completed through a polarization maintaining optical fiber bundle, and the detection precision is improved. After the linearly polarized light is subjected to multiple scattering in the subsurface damage area, the polarization state of the linearly polarized light can be changed. The detection of the subsurface damage is realized by measuring an optical signal of which the polarization state is changed; and meanwhile, the surface roughness of the sample to be detected does not influence the subsurface detection signal. The expansion of an imaging view field is realized by means of regulation and control of the piezoelectric scanning module, and finally, high-resolution subsurface damage imaging is completed by the image processing system. The detection device can be embedded into a machine tool system, high-precision in-situ measurement of a complex profile component is achieved, and real-time online monitoring of the machining process is supported.

Description

TECHNICAL FIELD

[0001] The application provides a flexible laser scattering detection device, and belongs to the technical field of nondestructive testing. BACKGROUND

[0002] With the development of intelligent manufacturing technology towards high precision and flexibility, modern industry has put forward strict requirements for the processing and detection of complex components. In the time-space multi-dimensional scale, achieving multi-degree-of-freedom, high-resolution and high-precision collaborative measurement has become a core challenge to improve manufacturing efficiency. Although current nondestructive testing technologies show diversified development trend, there are still significant limitations in the detection of complex surfaces in the aviation industry: acoustic detection is restricted by surface roughness, thermal detection is difficult to balance efficiency and accuracy, X-ray three-dimensional reconstruction is limited by sample size and cost, terahertz technology faces signal interpretation difficulties, and eddy current / resistance method has a detection depth bottleneck. What is particularly key is that existing technologies are difficult to meet the real-time detection requirements of high speed, high resolution and high sensitivity at the same time. This technical bottleneck is particularly prominent in the processing of components with complex curved surface characteristics such as aircraft engine blades: on the one hand, the traditional off-line detection method leads to a long processing-measuring iteration cycle; on the other hand, although non-contact methods such as laser interference have nanometer-level sensitivity, they are strict in surface finish and difficult to integrate into the in-situ detection system of the machine tool.

[0003] CN113340852B relates to a laser scattering detection device for processing damage, which realizes three-dimensional detection of internal damage of a sample by using double detectors for detection. However, the detection device still has obvious deficiencies in the detection of complex surface components and narrow space scenes. The overall structural design is difficult to adapt to the detection requirements of complex features such as narrow gaps and deep grooves, and the rigidity of the mechanical structure limits the flexible adjustment capability in the closed space, resulting in the inability to accurately align the detection area. This problem is particularly prominent in the detection of aircraft engine blades: the device is difficult to penetrate into the complex cavity structure of the blade, and it is also difficult to adapt to the detection angle requirements of high-curvature surfaces, making key parts such as mortise and air film holes of the blade become blind areas of detection. The lack of space adaptability seriously affects the integrity and accuracy of the overall detection, and restricts the realization of closed-loop control of processing quality. SUMMARY

[0004] The application aims to solve the above-mentioned problems existing in the prior art detection device, and provides a flexible laser scattering detection device, an operation method and application thereof. The device has excellent operation flexibility in complex narrow spaces due to the design of a miniature probe, can efficiently adapt to the detection requirements in restricted environments, and realizes high-resolution and high-sensitivity real-time detection of subsurface damage. It is suitable for complex surface components such as aircraft engine blades and narrow space detection scenes.

[0005] Technical solution: In order to achieve the above invention purposes, the application adopts the following technical solutions: A flexible laser scattering detection device, comprising a laser, a polarizer, a mirror, a polarization beam splitter, a pinhole, a detector, a scanning galvanometer, a polarization maintaining fiber bundle, a piezoelectric scanning module, a lens group, a detection probe, an image acquisition system, an image processing system and a motion control system.

[0006] The laser provides a signal source for optical detection; The polarizer converts the non-polarized or partially polarized light output by the laser into linearly polarized light; The mirror is used for light path control, which changes the light path direction to adapt to the system layout; The polarization beam splitter separates light of different polarization states by reflection and transmission; The function of the pinhole is to retain the light at the focal plane and block the stray light signal at the non-focal plane; The detector converts the collected light signal into an electrical signal; The scanning galvanometer is used to change the angle of the light beam to drive the laser spot to complete scanning in the detection area. The lens group is composed of two orthogonal installed galvanometers; The polarization maintaining fiber bundle is composed of multiple polarization maintaining fibers, which is used to transmit optical signals and maintain the polarization state of light.

[0007] The piezoelectric scanning module is composed of a piezoelectric driver, a piezoelectric scanner and a connecting cable. The piezoelectric driver drives the piezoelectric scanner to perform micron-level displacement through high-precision voltage control, and drives the end of the polarization maintaining fiber bundle to realize positioning, thereby expanding the imaging field of view of the system. The connecting cable and the polarization maintaining fiber bundle are jointly packaged in a medical-grade sealed tube.

[0008] The lens group is composed of three lenses. The first is a coupling objective lens, which is located below the scanning galvanometer and can focus the laser into a single optical fiber in the polarization maintaining fiber bundle. The second is a collection lens located on the left side of the polarization beam splitter, which focuses the light for the detector to collect. The third is a gradient refractive index lens, which can focus the laser on the sample to be detected and collect the scattered light generated by the sub-surface of the sample. The coupling objective lens, the collection lens and the gradient refractive index lens are in a conjugate relationship, which makes the detector only receive the light at the focal point of the sample to be detected, thereby realizing high-resolution point-to-point imaging.

[0009] The detection probe is composed of a miniature piezoelectric scanner, a polarization maintaining fiber bundle and a gradient refractive index lens.

[0010] In the image acquisition system, the laser scattering signal is filtered by a pinhole, converted into an electrical signal by a detector, and then collected by a high-speed acquisition card. The acquisition card corrects and reorganizes the signal row by row, and finally transmits the processed image data to a computer. The image processing system integrates three core functions: image distortion correction, high-resolution image reconstruction, and image denoising. The motion control system controls the scanning galvanometer and the piezoelectric scanner to realize the scanning function of the imaging device.

[0011] The flexible laser scattering detection device described above integrates all optical components and equipment except the detection probe and the sealing tube connected thereto into the main unit. According to the processing requirements, the detection probe is embedded into the machine tool system to realize real-time monitoring and in-situ measurement during the processing. The main unit supports fixed installation or mobile roller configuration to ensure the flexible deployment capability of the detection system.

[0012] By presetting the motion trajectory of the scanning galvanometer, the laser beam focused by the optical system can be incident into the specified single optical fiber in the polarization maintaining fiber bundle. By dynamically controlling the position switching of the focused spot in the fiber array, high-precision discrete point-to-point scanning imaging is realized.

[0013] The motion control system uses a hierarchical scanning strategy to achieve cooperative control. First, the scanning galvanometer completes the preset path scanning of the current field. Then the piezoelectric scanner positions the end of the polarization maintaining fiber bundle to the next position. Then the scanning galvanometer performs the scanning task again. This alternating control mode is repeated until the preset detection area is covered.

[0014] During the detection process of the flexible polarization laser scattering imaging system, the polarization state of the linearly polarized light changes after multiple scattering in the subsurface damage area. By measuring the change in the polarization state of the light signal, subsurface damage detection can be achieved; at the same time, the surface roughness of the sample to be detected will not affect the subsurface detection signal. The specific steps are as follows: (1) The light output by the laser is converted into linearly polarized light by a polarizer; the linearly polarized parallel light is reflected by a mirror and then transmitted through a polarization beam splitter to a scanning galvanometer. (2) The laser is deflected by the orthogonally installed scanning galvanometer in two dimensions, and then focused into a single optical fiber in the polarization maintaining fiber bundle by a coupling objective lens; the laser is transmitted by the optical fiber and focused on the sample to be detected by a gradient refractive index lens. (3) The scattered light signal is received by the gradient refractive index lens, transmitted by the optical fiber to the coupling objective lens, and then returned to the polarization beam splitter by the scanning galvanometer. (4) The polarization state of the light scattered by the subsurface damage is different from that of the incident laser. When these lights pass through the polarization beam splitter, the part with the same polarization state as the incident light is transmitted, while the part with the different polarization state is reflected. The reflected light is focused by the collecting lens and collected by the detector through the pinhole. (5) The scattered light signal collected by the detector is converted into an electrical signal, which is then converted into an analog-to-digital signal by a high-speed acquisition card and processed by a computer to generate an image.

[0015] (6) The motion control system controls the scanning galvanometer to complete the rapid scanning of the preset area. Then, it can drive the high-precision piezoelectric scanner to drive the end of the polarization-maintaining fiber bundle to perform micron-level displacement. Through the coordinated cooperation of galvanometer scanning and piezoelectric positioning, the imaging field of view is expanded.

[0016] Beneficial effects: Compared with existing detection systems, the present invention has the following beneficial effects: 1. The structure of the miniature detection probe of this invention enhances the flexibility of the detection process. The probe features a lightweight design, allowing direct embedding into machine tool systems. It is particularly suitable for detecting complex components such as engine blades and can adapt to special detection scenarios such as curved contours, deep grooves, and confined spaces. Its compact structure allows the probe to directly reach the damaged area without significant adjustments to the object being inspected, improving detection efficiency and operability.

[0017] 2. In this invention, the high-speed deflection of two orthogonally mounted scanning galvanometers, the efficient light transmission of optical fibers, and the point-to-point scanning mode construct a high-precision data acquisition system. The image processing system optimizes the raw data through algorithms such as distortion correction and high-resolution reconstruction. These two components form a synergistic mechanism, enabling the polarized laser scattering imaging device to have real-time response capabilities and improving its damage detection resolution.

[0018] 3. The polarized laser scattering technology in this invention combines high sensitivity with resistance to surface roughness interference in subsurface damage detection. This invention can detect fine subsurface damage that is difficult to identify using traditional optical detection methods, thus improving the ability to detect damage and defects.

[0019] 4. The piezoelectric scanning module in this invention expands the imaging field of view through high-precision displacement control. By coordinating the scanning galvanometer and the piezoelectric scanning module with the motion control system, it ensures that the minute area containing the micro-crack is included in the detection range, reducing the risk of missed detection due to field-of-view limitations and improving the completeness of damage detection. Attached Figure Description Figure 1 This is an optical path diagram of the flexible laser scattering detection device of the present invention; Figure 2 This is a schematic diagram of the structure of the detection probe 14 in the device of the present invention; Figure 3This is a schematic diagram of the polarization-maintaining fiber bundle end face and scanning path in Example 1; Figure 4 This is a graph showing the detection results of Example 1.

[0020] Explanation of key reference numerals in the attached figures: 1-Laser; 2-Optical path; 3-Polarizer; 4-Mirror; 5-Polarization beam splitter; 6-Collection lens; 7-Pinhole; 8-Detector; 9-Scanning galvanometer; 10-Coupled objective lens; 11-Polarization-maintaining fiber bundle; 12-Connecting cable for piezoelectric scanner; 13-Piezoelectric actuator; 14-Detection probe; 15-Piezoelectric scanner; 16-Gradient refractive index lens; 17-Fiber core; 18-Fiber cladding; 19-Fiber arrangement gap; 20-Scanning path. Detailed Implementation

[0021] The present invention will now be further described with reference to the accompanying drawings.

[0022] like Figure 1 As shown, a flexible polarized laser scattering imaging device includes a laser 1, a polarizer 3, a reflector 4, a polarizing beam splitter 5, a pinhole 7, a detector 8, a scanning galvanometer 9, a polarization-maintaining fiber bundle 11, a piezoelectric scanning module, a lens group, a detection probe 14, an image acquisition system, an image processing system, and a motion control system.

[0023] The laser 1 provides a signal source for optical detection. The polarizer 3, installed at the output of the laser 1, controls the polarization direction of the beam, converting unpolarized or partially polarized light output by the laser 1 into linearly polarized light. The polarization beam splitter 5 separates light of different polarization states through reflection and transmission. The pinhole 7 retains light at the focal plane and blocks stray light signals from the non-focal plane. Light passing through the pinhole 7 is focused, collected by the detector 8, and the optical signal is converted into an electrical signal. The scanning galvanometer 9 changes the beam angle, driving the laser spot to scan the detection area. This mirror assembly consists of two orthogonally mounted scanning galvanometers. The polarization-maintaining fiber bundle 11, composed of multiple polarization-maintaining fibers, transmits optical signals and maintains the polarization state of the light. The beam transmitted through the polarization beam splitter 5 is angled twice consecutively by the two scanning galvanometers 9, resulting in an output direction parallel to the input beam. It is then focused onto the polarization-maintaining fiber bundle 11 by the coupling objective lens 10. The polarization-maintaining fiber bundle 11 is connected to the detection probe 14 via a piezoelectric scanning module.

[0024] The detection probe 14 includes a miniature piezoelectric scanner 15, a polarization-maintaining fiber bundle 11, and a gradient refractive index lens 16. Light focused by the coupling lens 10 is input into the polarization-maintaining fiber bundle 11. After transmission through the fiber, the laser light is focused onto the sample to be tested by the gradient refractive index lens 16. The scattered light signal is received by the gradient refractive index lens, transmitted through the fiber to the coupling lens, and then returned to the polarization beam splitter via a scanning galvanometer. The light scattered by subsurface damage has a different polarization state than the incident laser. When this light passes through the polarization beam splitter, the portion with the same polarization state as the incident light is transmitted, while the portion with a different polarization state is reflected. The reflected light is focused by the collecting lens, filtered through a pinhole, and then collected by the detector. The scattered light signal is converted into an electrical signal and processed by a computer to generate an image, thus expanding the imaging field of view. This detection probe enables flexible detection at all angles, adapts to the measurement needs of complex surface components, and meets the in-situ detection requirements of various confined spaces during processing.

[0025] The piezoelectric scanning module includes a piezoelectric driver 13, a piezoelectric scanner 15, and a connecting cable 12 between the two. The piezoelectric driver 13 drives the piezoelectric scanner 15, causing the polarization-maintaining fiber bundle 11 to scan in a spiral pattern, thereby expanding the imaging range. The connecting cable 12 and the polarization-maintaining fiber bundle 11 are encapsulated together in a medical-grade sealed tube.

[0026] The lens group consists of three lenses. The first is a coupling objective 10, located below the scanning galvanometer 9, which focuses the laser beam into a single fiber within the polarization-maintaining fiber bundle 11. The second is a collecting lens 6, located to the left of the polarization beam splitter 5, which focuses the light for the detector 8 to collect. The third is a gradient refractive index lens 16, which focuses the laser beam onto the sample to be tested and collects scattered light generated at the sample's subsurface. The coupling objective 10, collecting lens 6, and gradient refractive index lens 16 are conjugate, a characteristic that allows the detector 8 to receive only the light at the focal point of the sample to be tested, thereby achieving high-resolution point-to-point imaging.

[0027] In the image acquisition system, the laser scattering signal is filtered by pinhole 7 and converted into an electrical signal by detector 8, which is then acquired by a high-speed acquisition card. The acquisition card performs line-by-line correction and reconstruction of the signal, and finally transmits the processed image data to the image processing system (computer). The image processing system integrates three core functions: image distortion correction, high-resolution image reconstruction, and image denoising. The motion control system controls the scanning mirror 9 and the piezoelectric scanner 15 by controlling the piezoelectric driver 13 of the piezoelectric scanning module, thereby realizing the scanning function of the imaging device.

[0028] The aforementioned flexible laser scattering detection device integrates all optical components and equipment, except for the detection probe and its connected sealed tube, into the main unit. The detection probe is embedded into the machine tool system according to processing requirements, enabling real-time monitoring and in-situ measurement during the processing. The main unit supports fixed installation or a movable roller configuration, ensuring flexible deployment capabilities of the detection system.

[0029] In the aforementioned flexible polarized laser scattering imaging device, the laser output light is converted into linearly polarized light during the detection process. The scanning mirror 9 controls the laser movement and scanning, thereby accurately scanning the damaged area. The image signal is transmitted via a polarization-maintaining fiber bundle. After multiple scattering in the subsurface damage area, the polarization state of the linearly polarized light changes. By measuring the light signal with the changed polarization state, subsurface damage can be detected; simultaneously, the surface roughness of the sample does not affect the subsurface detection signal. The specific steps are as follows: (1) The light output from the laser 1 is converted into linearly polarized light by the polarizer 3; the linearly polarized parallel light is reflected by the mirror 4 and then shines on the scanning mirror 9 through the polarizing beam splitter 5. (2) The laser is deflected in two dimensions by the orthogonally mounted scanning galvanometer 9, and then focused by the coupling objective 10 into a single fiber in the polarization-maintaining fiber bundle 10; after the laser is transmitted through the fiber, it is focused on the sample to be tested by the gradient refractive index lens 16. (3) The scattered light signal is received by the gradient refractive index lens 16, transmitted to the coupling objective lens 10 via optical fiber, and then returned to the polarization beam splitter 5 via the scanning galvanometer 9. (4) The polarization state of the light scattered by the subsurface damage is different from that of the incident laser. When these lights pass through the polarization beam splitter 5, the part with the same polarization state as the incident light is transmitted, while the part with a different polarization state is reflected. The reflected light is focused by the collecting lens 6 and collected by the detector 8 through the pinhole 7. (5) The scattered light signal collected by the detector 8 is converted into an electrical signal, which is then converted into an analog-to-digital signal by a high-speed acquisition card and processed by a computer to generate an image.

[0030] (6) The motion control system controls the scanning galvanometer 9 to complete the rapid scanning of the preset area. Then, it can drive the high-precision piezoelectric scanner 15 to drive the end of the polarization-maintaining fiber bundle 11 to perform micron-level displacement. Through the coordinated cooperation of galvanometer scanning and piezoelectric positioning, the imaging field of view is expanded. Example

[0031] In this embodiment, a polarized laser scattering imaging device is used to detect minute cracks in engine blades.

[0032] The detection probe 14 in the polarized laser scattering imaging device is moved to the suspected damage area in the engine blade, such as... Figure 1As shown, the laser output from laser 1 passes sequentially through polarizer 3, mirror 4, polarization beam splitter 5, scanning galvanometer 9, coupling objective 10, polarization-maintaining fiber bundle 11, and gradient refractive index lens 16, and is finally focused onto the area to be detected. After being focused by coupling objective 10, the laser is coupled to a single polarization-maintaining fiber in polarization-maintaining fiber bundle 11; subsequently, the motion control system drives scanning galvanometer 9 to move the laser spot along... Figure 3 The predetermined trajectory shown scans the fiber bundle end face; Figure 3 In the process, the scanning trajectory is a serpentine pattern that spreads outward from the center. The speed of the scanning galvanometer 9 changes nonlinearly, with the fastest scanning speed at the center of a single scanning path, while the speed gradually decreases when the beam reaches the edges of both ends of the path.

[0033] If subsurface damage exists in the detection area, the incident light will undergo multiple scattering, resulting in a change in polarization state. These light signals with altered polarization states are collected by the detection probe 14 and transmitted to the back-end optical system. The returned light signal illuminates the photodetector 8, and the pinhole 7 in front of the detector 8 blocks stray light outside the focal plane, thereby improving axial resolution and signal-to-noise ratio. The scattered light signal from the focal point passes through the pinhole 7, and the detector 8 converts the light signal into an electrical signal. After amplification, it is converted into a digital signal by a high-speed acquisition card, and then processed by a computer to generate an image. Furthermore, the piezoelectric scanner 15 can be controlled by a motion control system to move the end of the polarization-maintaining fiber bundle 11, such as... Figure 2 As shown, this is used to expand the imaging field of view. The polarization-maintaining fiber bundle 11 is composed of a large number of tightly packed single optical fibers. Due to the significant difference in transmittance between the fiber core 17 and the fiber cladding 18, the light intensity signal in the core 17 region is significantly higher than that in the cladding 18 region in the image acquired by the polarization laser scattering imaging device, resulting in obvious pixelation artifacts and severely affecting image quality. Therefore, this embodiment employs an image reconstruction algorithm based on fiber center point interpolation, achieving high-resolution imaging through the following steps: First, the fiber center coordinates are located. Image processing algorithms are used to identify the geometric center position of each fiber; these center points will serve as the reference nodes for subsequent interpolation calculations. Second, a triangular interpolation algorithm is used to reconstruct the light intensity distribution. The intensity value measured at the center of each fiber core is considered a real physical quantity. By constructing a Delaunay triangular mesh between adjacent fiber center points, a continuous light intensity field is mathematically reconstructed, ultimately achieving high-fidelity crack imaging.

[0034] With the help of image processing systems that offer functions such as image distortion correction and high-resolution image reconstruction, real-time imaging of minute cracks in blades can be achieved flexibly and conveniently. Figure 4 As shown.

[0035] This invention is not limited to this embodiment. Any equivalent concept or modification within the technical scope disclosed in this invention shall be included within the protection scope of this invention.

Claims

1. A flexible laser scattering detection device, characterized in that, Includes a laser (1), a polarizer (2), a mirror (4), a polarization beam splitter (5), a detector (8), a scanning mirror (9), a polarization-maintaining fiber bundle, a piezoelectric scanning module, and a detection probe (14). The laser (1) provides a signal source for optical detection; The polarizer (3) is installed at the output end of the laser (1) to control the polarization direction of the beam and convert the unpolarized or partially polarized light output by the laser into linearly polarized light. The reflector (4) is installed behind the polarizer (3) for optical path control, and the optical path direction is changed to adapt to the system layout. The polarization beam splitter (5) is installed in the optical output direction of the reflector (4). The light reflected by the reflector (4) passes through the polarization beam splitter (5), is changed at an angle by the scanning galvanometer (9), and is focused by the coupling objective (10) into a single fiber of the polarization-maintaining fiber bundle (11). The polarization-maintaining fiber bundle is connected to the detection probe (14) via the piezoelectric actuator (13). The scattered light returning from the sample is collected by the detection probe (14), and then passes back through the polarization-maintaining fiber bundle (11) and the optical system, and then through the scanning galvanometer (9) to the polarization beam splitter (5). The polarization beam splitter (5) separates light of different polarization states through reflection and transmission. The light reflected by the polarization beam splitter (5) is focused by the collecting lens (6), filtered by the pinhole (7), and then collected by the detector (8). The detector converts the collected optical signal into an electrical signal.

2. The flexible laser scattering detection device according to claim 1, characterized in that, The detection probe includes a piezoelectric scanner (15), a polarization-maintaining fiber bundle (11), and a gradient refractive index lens (16). The light focused by the coupling objective (10) is input into the polarization-maintaining fiber bundle (11). After the laser is transmitted through the fiber, it is focused on the sample to be tested by the gradient refractive index lens (16). The scattered light signal is received by the gradient refractive index lens, transmitted through the fiber to the coupling objective, and then returned to the polarization beam splitter through the scanning galvanometer. The light scattered by subsurface damage has a different polarization state than the incident laser. When this light passes through a polarizing beam splitter, the part with the same polarization state as the incident light is transmitted, while the part with a different polarization state is reflected. The reflected light is focused by a collecting lens, filtered through a pinhole, and then collected by a detector. The scattered light signal is converted into an electrical signal and processed by a computer to generate an image.

3. The flexible laser scattering detection device according to claim 1, characterized in that, There are two scanning galvanometers (9), which are installed orthogonally to each other.

4. The flexible laser scattering detection device according to claim 2, characterized in that, The coupling objective (10), the collecting lens (6), and the gradient refractive index lens (16) are conjugate, so that the detector can only receive the light at the focal point of the sample to be detected, thereby achieving high-resolution point-to-point imaging.

5. The flexible laser scattering detection device according to claim 1, characterized in that, The piezoelectric scanning module includes: a piezoelectric driver, a piezoelectric scanner, and a connecting cable; the piezoelectric driver drives the piezoelectric scanner to perform micron-level displacement through voltage, thereby positioning the end of the polarization-maintaining fiber bundle and expanding the system's imaging field of view; the connecting cable and the polarization-maintaining fiber bundle are encapsulated together in a medical-grade sealed tube.

6. The operation method of the flexible laser scattering detection device according to claim 1, characterized in that, The light emitted by the laser is converted into linearly polarized light. The laser is moved and scanned by the scanning galvanometer (9) to accurately scan the damaged area. The image signal is transmitted through the polarization-maintaining fiber bundle. After multiple scattering in the subsurface damage area of ​​the sample, the polarization state of the linearly polarized light changes. The subsurface damage is detected by measuring the light signal with the changed polarization state. At the same time, the surface roughness of the sample to be tested will not affect the subsurface detection signal. In the image acquisition system, the laser scattering signal is converted into an electrical signal by the detector after being filtered by a pinhole, and then acquired by a high-speed acquisition card. The acquisition card performs line-by-line correction and reconstruction of the signal, and finally transmits the processed image data to the computer. The image processing system performs image distortion correction, high-resolution image reconstruction, and image denoising. The motion control system realizes the scanning function of the imaging device by controlling the scanning galvanometer and the piezoelectric scanner.

7. The operation method of the flexible laser scattering detection device according to claim 1, characterized in that, The steps are as follows: Step 1: The light output from the laser (1) is converted into linearly polarized light by the polarizer (3); the linearly polarized parallel light is reflected by the mirror (4) and then shines on the scanning mirror (9) through the polarizing beam splitter (5). Step 2: The laser is deflected in two dimensions by an orthogonally mounted scanning galvanometer (9), and then focused by a coupling objective (10) onto a single fiber in a polarization-maintaining fiber bundle (10); after being transmitted through the fiber, the laser is focused onto the sample to be tested by a gradient refractive index lens (16). Step 3: The scattered light signal is received by the gradient refractive index lens (16), transmitted to the coupling objective (10) via optical fiber, and then returned to the polarization beam splitter (5) via the scanning galvanometer (9). Step 4: The light scattered by the subsurface damage has a different polarization state than the incident laser. When these lights pass through the polarization beam splitter (5), the part with the same polarization state as the incident light is transmitted, while the part with a different polarization state is reflected. The reflected light is focused by the collecting lens (6), filtered through the pinhole 7, and collected by the detector (8). Step 5: The scattered light signal collected by the detector (8) is converted into an electrical signal, which is then converted from analog to digital by a high-speed acquisition card and processed by a computer to generate an image. Step 6: The motion control system controls the scanning galvanometer (9) to complete the rapid scanning of the preset area. Then, it can drive the high-precision piezoelectric scanner (15) to drive the end of the polarization-maintaining fiber bundle (11) to perform micron-level displacement. Through the coordinated cooperation of galvanometer scanning and piezoelectric positioning, the imaging field of view is expanded.

8. The flexible laser scattering detection device according to claim 1 is used for non-destructive testing of damage to complex surface components and confined spaces.

9. The application according to claim 2, characterized in that, The damage encompasses both surface and subsurface damage, including pores, cracks, inclusions, and delamination introduced into the material during processing.

10. The flexible laser scattering detection device of claim 1, used for real-time monitoring and in-situ measurement, integrates all optical components and equipment except for the detection probe and its connected sealing tube into the main unit; the detection probe is embedded into the machine tool system according to processing requirements to realize real-time monitoring and in-situ measurement of the processing process; the main unit supports fixed installation or movable roller configuration to ensure the flexible deployment capability of the detection system.

Images