A composite material defect detection system and method

Abstract

The application discloses a composite material defect detection system, and relates to the field of nondestructive testing, which comprises the following steps: a pulse laser is connected with a host computer, a first laser is emitted to the surface of the composite material according to first laser parameters, and a second laser is emitted to the defect on the surface of the composite material according to second laser parameters; an infrared thermal imager is connected with the host computer, the temperature field of the surface of the composite material is monitored by scanning the first laser, and the collected thermal radiation image is transmitted to the host computer; a photoelectric detection device is connected with the host computer, the ultrasonic wave generated by the defect on the surface of the composite material is monitored, converted and demodulated by scanning the second laser, and the defect laser ultrasonic image obtained after demodulation is transmitted to the host computer; the host computer determines the first laser parameters, determines the second laser parameters according to the defect position of the composite material obtained from the thermal radiation image, and determines the defect information of the composite material. The application can quickly, non-contact and nondestructively detect the surface defect of the composite material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nondestructive testing, in particular to a composite material defect detection system and method. BACKGROUND

[0002] Carbon fiber composite materials have high specific strength and specific modulus, low density, corrosion resistance, high temperature resistance and radiation resistance, and are widely used in military and civilian fields. However, during manufacturing, transportation and processing, many unavoidable damages such as debonding, scratching and cracking may occur, which will have a negative impact on the service of carbon fiber composite materials and their components. Therefore, in order to ensure the high performance, high quality and safe operation of carbon fiber composite materials and their components, it is necessary to conduct nondestructive testing.

[0003] Nondestructive testing does not contact the tested object and does not damage the performance and service life of the tested object. At present, many scholars have studied the detection of surface defects of carbon fiber composite materials, such as eddy current testing method, X-ray testing method, microwave testing method, pulse infrared thermal imaging method and ultrasonic testing method. However, these conventional nondestructive testing methods cannot effectively detect some complex large-size curved surface structures such as aircraft wings, and these detection techniques also have certain limitations. For example, it is difficult to judge the type, size and shape of internal defects of the tested sample by eddy current testing method, long-term use of X-ray testing method may cause certain harm to human body, and microwave testing method also has certain limitations, its sensitivity is affected by working frequency, and it is not easy to penetrate carbon fiber composite materials with good conductivity, etc. Some scholars try to use laser to detect surface damage of carbon fiber composite materials, but are limited by the heat ablation of laser thermal radiation, the difficulty in obtaining detailed defect information or slow detection speed, and the laser nondestructive testing technology for surface damage of carbon fiber composite materials is still in its infancy. SUMMARY

[0004] The purpose of the present application is to provide a composite material defect detection system and method, which can realize rapid, non-contact and nondestructive detection of surface defects of composite materials.

[0005] To achieve the above purpose, the present application provides the following solutions:

[0006] A composite material defect detection system, the system comprising: a pulsed laser, an infrared thermal imager, a photoelectric detection device and an upper computer.

[0007] The pulse laser is connected with the host computer, and is used for emitting first laser to the surface of the composite material according to first laser parameters sent by the host computer, and emitting second laser to defects on the surface of the composite material according to second laser parameters sent by the host computer; the first laser parameters and the second laser parameters both include laser energy density, scanning speed and scanning path;

[0008] The infrared thermal imager is connected with the host computer, and is used for monitoring a temperature field of the surface of the composite material scanned by the first laser and transmitting the collected thermal radiation image to the host computer;

[0009] The photoelectric detection device is connected with the host computer, and is used for monitoring, converting and demodulating ultrasonic waves generated by defects on the surface of the composite material scanned by the second laser, and transmitting the defect laser ultrasonic image obtained after demodulation to the host computer;

[0010] The host computer is used for determining the first laser parameters according to the characteristics of the composite material and sending the first laser parameters to the pulse laser, obtaining the defect position of the composite material according to the thermal radiation image, determining the second laser parameters according to the defect position and the characteristics of the composite material and sending the second laser parameters to the pulse laser, and is also used for fusing and superimposing the defect laser ultrasonic image and the thermal radiation image, and determining the defect information of the composite material according to the fused and superimposed image; the defect information includes defect position, defect length, defect width and defect depth.

[0011] Optionally, the host computer includes a control module and an image fusion processing module;

[0012] The control module is connected with the pulse laser, and is used for determining the first laser parameters according to the characteristics of the composite material and sending the first laser parameters to the pulse laser, and determining the second laser parameters according to the defect position and the characteristics of the composite material and sending the second laser parameters to the pulse laser;

[0013] The image fusion processing module is connected with the control module, the infrared thermal imager and the photoelectric detection device respectively, and is used for obtaining the defect position of the composite material according to the received thermal radiation image, sending the defect position to the control module, fusing and superimposing the defect laser ultrasonic image and the thermal radiation image, and determining the defect information of the composite material according to the fused and superimposed image.

[0014] Optionally, the host computer further includes a display terminal;

[0015] The display terminal is connected with the image fusion processing module, and is used for displaying the defect laser ultrasonic image, the thermal radiation image, the fused and superimposed image, the defect position of the composite material and the defect information of the composite material.

[0016] Optionally, the photoelectric detection device comprises a photoelectric detector, an ultrasonic detection tracker and an interferometer.

[0017] The ultrasonic detection tracker is used for monitoring ultrasonic waves generated by defects on the surface of the composite material scanned by the second laser;

[0018] The photoelectric detector is connected with the ultrasonic detection tracker, and is used for moving along the ultrasonic waves monitored by the ultrasonic detection tracker, receiving the ultrasonic waves, and converting the received ultrasonic waves into light information;

[0019] The interferometer is connected with the photoelectric detector and the upper computer respectively, and is used for receiving the light information, demodulating the ultrasonic waves according to the light information, and transmitting the defect laser ultrasonic image obtained after demodulation to the upper computer.

[0020] Optionally, the system further comprises a lens.

[0021] The lens is arranged on the light paths of the first laser and the second laser, and is used for focusing the first laser and the second laser; the first laser and the second laser irradiate the surface of the composite material through the lens.

[0022] Optionally, the pulse laser is a nanosecond laser, a picosecond laser or a femtosecond laser.

[0023] Optionally, the average power of the pulse laser is greater than 50W.

[0024] Optionally, the infrared thermal imager is a general-purpose industrial infrared thermal imager.

[0025] A composite material defect detection method applied to the composite material defect detection system, the method comprising:

[0026] determining first laser parameters according to the characteristics of the composite material, and sending the first laser parameters to the pulse laser; the first laser parameters include laser energy density, scanning speed and scanning path;

[0027] acquiring a thermal radiation image obtained by scanning the surface of the composite material according to the first laser parameters;

[0028] determining the defect position of the surface of the composite material according to the thermal radiation image;

[0029] determine second laser parameters according to the defect position and the characteristics of the composite material, and send the second laser parameters to the pulsed laser; the second laser parameters include laser energy density, scanning speed and scanning path;

[0030] obtain a defect laser ultrasonic image of the defect of the surface of the composite material scanned by the second laser parameters;

[0031] superimpose the defect laser ultrasonic image and the thermal radiation image to determine defect information of the surface of the composite material; the defect information includes defect position, defect length, defect width and defect depth.

[0032] Optionally, the method further comprises:

[0033] visually display the defect laser ultrasonic image, the thermal radiation image, the superimposed image, the defect position of the composite material and the defect information of the composite material.

[0034] According to the specific embodiments of the present application, the following technical effects are provided:

[0035] The composite material defect detection system provided by the application comprises a pulsed laser, an infrared thermal imager, a photoelectric detection device and an upper computer. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0037] Figure 1 The module diagram of the composite material defect detection system provided by the present application is shown in the figure.

[0038] Figure 2 The schematic diagram of the surface defect of the carbon fiber composite material is shown in the figure.

[0039] Figure 3A laser thermal radiation imaging diagram of a surface defect of a carbon fiber composite material;

[0040] Figure 4 A schematic diagram of a composite material defect detection system provided by the present application for detecting a surface of a carbon fiber composite material;

[0041] Figure 5 A laser excited ultrasonic imaging diagram of a surface defect of a carbon fiber composite material;

[0042] Figure 6 A laser "thermal radiation-ultrasonic excitation" composite imaging diagram of a surface defect of a carbon fiber composite material;

[0043] Figure 7 A flowchart of a composite material defect detection method provided by the present application;

[0044] Figure 8 A work flowchart of a composite material defect detection system provided by the present application. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described 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.

[0046] The purpose of the present application is to provide a composite material defect detection system and method, which can realize rapid, non-contact and non-destructive detection of surface defects of a composite material.

[0047] The system adopts a method of fusing laser thermal radiation imaging and laser excited ultrasonic wave field imaging to realize rapid, non-contact and non-destructive visual detection of surface defects of a carbon fiber composite material. First, a high energy density laser is regulated and controlled to perform rapid thermal imaging scanning on the surface of the carbon fiber composite material at a high scanning speed, so as to form a thermal imaging diagram of the surface to be detected and rapidly and accurately locate the defect position. Then, a low energy density laser is regulated and controlled to perform laser excited ultrasonic wave field imaging scanning on the defect position at a low scanning speed, so as to characterize the length, width and depth size of the defect, thereby realizing rapid and accurate detection of the defect position and specific defect size information of the surface of the carbon fiber composite material by scanning with different energy densities of a single laser source. The system has the remarkable characteristics of rapidness, high efficiency, non-destructiveness, non-contact and visualization, and can be applied to the detection of surface defects of a carbon fiber composite material with high efficiency and high quality.

[0048] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0049] As shown in Figure 1 The present application provides a composite material defect detection system, which comprises a pulsed laser, an infrared thermal imager, a photoelectric detection device and an upper computer; the composite material comprises a carbon fiber composite material, and also comprises a titanium alloy, an aluminum alloy, an iron-based alloy and other metal materials.

[0050] The pulsed laser is connected with the upper computer, and is used for emitting first laser to the surface of the composite material according to the first laser parameter sent by the upper computer, and emitting second laser to the defect on the surface of the composite material according to the second laser parameter sent by the upper computer; the first laser parameter and the second laser parameter both comprise a laser energy density, a scanning speed and a scanning path; specifically, the pulsed laser is a nanosecond laser, a picosecond laser or a femtosecond laser; the energy density of the pulsed laser is adjustable, and the pulse width is adjustable.

[0051] In actual application, the pulsed laser is adjustable in power and adjustable in pulse width, the need of laser scanning thermal infrared fast imaging is considered, preferably, a laser with an average power greater than 50 W is selected, the sensitivity of the carbon fiber composite material to laser scanning thermal radiation is considered, and preferably, a picosecond or femtosecond laser is selected.

[0052] The infrared thermal imager is connected with the upper computer, and is used for monitoring the temperature field of the surface of the composite material scanned by the first laser and transmitting the collected thermal radiation image to the upper computer; specifically, the infrared thermal imager is a general industrial infrared thermal imager.

[0053] In actual application, as shown in Figure 2 and Figure 3 The infrared thermal imager can detect and identify the thermal radiation image characteristics of the relatively high energy density laser scanning, and is connected with the computer, so as to distinguish and locate the defect distribution of the test sample. According to the imaging principle of the infrared thermal imager, it can be divided into two kinds of photon detection and thermal detection, and according to the working wave band of the infrared thermal imager, it can be divided into long-wave, short-wave and medium-wave thermal imagers. The infrared thermal imager comprises an infrared detection tracker, the infrared detection tracker is connected with the detection head of the infrared thermal imager, the infrared detection tracker has a visual motion capture function, can drive the detection head of the infrared thermal imager to move along with the laser irradiation beam, so that the detection head of the infrared thermal imager receives the laser irradiation beam to obtain the thermal radiation image.

[0054] The infrared thermal imager is arranged at a proper position obliquely above the composite material to be detected, the instrument is attached with a visual motion capture module and an infrared detection tracker, the infrared detection tracker has the visual motion capture module and drives the detection head of the infrared thermal imager to move along the laser irradiation beam.

[0055] The photoelectric detection device is connected with the upper computer and is used for monitoring, converting and demodulating the ultrasonic wave generated by the defect of the surface of the composite material scanned by the second laser and transmitting the defect laser ultrasonic image obtained after demodulation to the upper computer. The photoelectric detector is arranged at a proper position obliquely above the workpiece to be detected.

[0056] The upper computer is used for determining the first laser parameter according to the characteristics of the composite material and sending the first laser parameter to the pulsed laser, obtaining the defect position of the composite material according to the thermal radiation image, determining the second laser parameter according to the defect position and the characteristics of the composite material and sending the second laser parameter to the pulsed laser, and is also used for fusing and superimposing the defect laser ultrasonic image and the thermal radiation image and determining the defect information of the composite material according to the fused and superimposed image; the defect information includes the defect position, the defect length, the defect width and the defect depth. The upper computer is a computer workstation.

[0057] As a specific embodiment, the upper computer includes a control module and an image fusion processing module.

[0058] The control module is connected with the pulsed laser, adopts common machine vision tracking technology according to preset energy matching of different types of materials and defect scanning operation action options, adjusts the parameter matching of the emitted laser and adjusts the scanning path and scanning action of the laser; specifically, the control module is used for determining the first laser parameter according to the characteristics of the composite material and sending the first laser parameter to the pulsed laser and determining the second laser parameter according to the defect position and the characteristics of the composite material and sending the second laser parameter to the pulsed laser; when laser thermal imaging detection is performed, the control module adopts high-energy and high-scanning-speed laser parameter matching; when laser excitation ultrasonic detection is performed, the control module adopts low-energy and low-scanning-speed laser parameter matching; specifically, the control module is a computer.

[0059] In actual application, for example, Figure 4 and Figure 5As shown, the control module is a preset laser beam parameter matching module, different laser parameter matching is set according to different material characteristics, two kinds of laser parameter matching of high energy / high scanning speed and low energy / low scanning speed are set for each material, high energy (i.e. high energy density and long pulse width) and high scanning speed parameter matching are adopted when laser thermal radiation scanning detection is carried out, and low energy (i.e. low energy density and short pulse width) and low scanning speed laser is adopted when laser excited ultrasonic detection is carried out, and according to the defect position distribution information fed back by the temperature field image, a secondary scanning path is planned, and laser excited ultrasonic detection is carried out.

[0060] The image fusion processing module is connected with the control module, the infrared thermal imager and the photoelectric detection device respectively, is used for acquiring the defect position of the composite material according to the received thermal radiation image, and sending the defect position to the control module, and fusing and superimposing the defect laser ultrasonic image and the thermal radiation image, and determining the defect information of the composite material according to the fused and superimposed image.

[0061] In actual application, as shown in the figure, Figure 6 As shown, the image fusion processing module fuses the thermal radiation image and the laser ultrasonic image into one image by using image fusion technology, that is, the temperature field and the ultrasonic wave field image are fused, that is, the laser "thermal radiation-ultrasonic excitation" composite image, the distribution position and the specific size of the surface defect of the composite material are obtained. The image fusion processing module has temperature field automatic comparison software and its database, by comparing the temperature field image after image fusion treatment, according to the temperature field distribution difference, the temperature field with difference is extracted and positioned, the defect position distribution information of the detected composite material surface is obtained, and the defect position distribution information is fed back to the control module for defect position fixed-point laser ultrasonic excitation scanning, the ultrasonic wave field image of the defect is obtained, and the temperature field image and the ultrasonic wave field image are fused, the fusion image of the position distribution and the size information of the detected defect is obtained, the accurate recognition of the defect is realized, and the accuracy and efficiency of the carbon fiber composite material surface defect detection are improved. Specifically, the image fusion software can be selected from picture synthesizer, Snapseed, picsart and the like. The image fusion processing module is a computer installed with image fusion software.

[0062] As a specific embodiment, the upper computer further comprises a display terminal;

[0063] The display terminal is connected with the image fusion processing module, and is used for displaying the defect laser ultrasonic image, the thermal radiation image, the fused and superimposed image, the defect position of the composite material and the defect information of the composite material.

[0064] As a specific embodiment, the photoelectric detection device comprises a photoelectric detector, an ultrasonic detection tracker and an interferometer.

[0065] The ultrasonic detection tracker is used for monitoring ultrasonic waves generated by defects on the surface of the composite material scanned by the second laser;

[0066] The photoelectric detector, connected with the ultrasonic detection tracker, is used for moving along the ultrasonic waves monitored by the ultrasonic detection tracker, receiving the ultrasonic waves, and converting the received ultrasonic waves into light information; the photoelectric detector is a general-purpose industrial photoelectric detector.

[0067] The interferometer, connected with the photoelectric detector and the host computer respectively, is used for receiving the light information, demodulating the ultrasonic waves according to the light information, and transmitting the defect laser ultrasonic image obtained after demodulation to the host computer; the interferometer has both non-interference detection technology and interference detection technology.

[0068] In actual application, the photoelectric detection device monitors, analyzes and processes ultrasonic waves generated by defects on the surface of the composite material; when the laser scans the surface of the composite material, ultrasonic vibration modulates the reflected light, so that ultrasonic vibration information is converted into light information; the interferometer can measure subtle optical path changes or light frequency changes, demodulate ultrasonic vibration information carried by the light signal, form an image containing specific defect information, and transmit the image to the host computer.

[0069] As a specific embodiment, the system further comprises a lens;

[0070] The lens is arranged on the light paths of the first laser and the second laser, and is used for focusing the first laser and the second laser; the first laser and the second laser irradiate the surface of the composite material after passing through the lens.

[0071] As shown in Figure 7 The present application provides a composite material defect detection method, applied to the composite material defect detection system, the method comprising:

[0072] Step S1: determining first laser parameters according to the characteristics of the composite material, and sending the first laser parameters to a pulsed laser; the first laser parameters include laser energy density, scanning speed and scanning path;

[0073] Step S2: obtaining a thermal radiation image obtained by scanning the surface of the composite material according to the first laser parameters;

[0074] Step S3: determining the defect position on the surface of the composite material according to the thermal radiation image;

[0075] Step S4: determining second laser parameters according to the defect position and the characteristics of the composite material, and sending the second laser parameters to the pulsed laser; the second laser parameters include laser energy density, scanning speed and scanning path;

[0076] Step S5: obtaining a defect laser ultrasonic image obtained by scanning the surface of the composite material with the second laser parameters;

[0077] Step S6: superimposing and fusing the defect laser ultrasonic image and the thermal radiation image to determine defect information of the surface of the composite material; the defect information includes defect position, defect length, defect width and defect depth.

[0078] As a specific embodiment, the method further comprises: visualizing and displaying the defect laser ultrasonic image, the thermal radiation image, the superimposed and fused image, the defect position of the composite material and the defect information of the composite material.

[0079] In actual application, as shown in the figure, Figure 8 The working process of the composite material defect detection system provided by the application is as follows:

[0080] 1. Start the computer workstation including the control module and the image fusion processing module, and start the pulsed laser, the infrared thermal imager and the photoelectric detection device, and debug the stability of the laser light source, the height / angle of the monitoring device and the action coordination;

[0081] 2. Control the pulsed laser to emit pulsed laser light source to scan the surface of the composite material to be detected through the control module, and the scanning path at this time is to scan the entire surface of the composite material. The infrared thermal imager receives the infrared radiation energy of the detected target by using the infrared detection head, and sends the collected thermal radiation image to the image fusion processing module; the thermal radiation image can reflect the defect position information of the composite sample.

[0082] 3. Compare the thermal radiation image containing the defect position information obtained with the temperature field comparison software and its database of the computer image fusion processing module to obtain the detected defect position information based on the temperature field;

[0083] 4. The control module automatically selects the laser parameter matching and ultrasonic excitation scanning path according to the defect position, and the photoelectric detection device collects and demodulates the ultrasonic wave to obtain the ultrasonic wave field image of the defect size information of the surface of the detected material.

[0084] 5. The image fusion processing module fuses the two images of the thermal radiation image and the laser ultrasonic image into one image to obtain the position distribution of the surface defects of the composite material and the size information image, i.e. a laser "thermal radiation-ultrasonic excitation" composite image, and to obtain the position distribution and size information of the surface defects of the composite material.

[0085] 6. The defect laser ultrasonic image, the thermal radiation image, the fused superimposed image, the defect position of the composite material and the defect information of the composite material are sent to a display terminal for visual display.

[0086] The present application is directed to the visualization detection of the surface defects of the carbon fiber composite material, taking the laser energy density and the scanning speed as the control objects. Firstly, a relatively high energy density and scanning speed pulsed laser is obtained by automatically matching the laser parameters through the computer, is focused through a focusing lens, is irradiated to the surface of the carbon fiber composite material, and the temperature field of the laser scanning is monitored by using an infrared thermal imager connected with the computer. The collected thermal radiation image is transmitted to the computer. Then, the computer as the control module of the laser parameters automatically matches the two parameters of the laser energy density and the scanning speed to obtain a relatively low energy density and scanning speed pulsed laser, and automatically plans and generates a scanning path for the defect position according to the defect position positioning information in the thermal radiation image. The laser irradiated by the pulsed laser after the control adjustment is irradiated to the surface of the defect position of the composite material. The ultrasonic waves generated by the scanning are monitored, converted and demodulated by a photoelectric detection device to form a laser ultrasonic image of the defect which is transmitted to the computer. Finally, the laser ultrasonic image and the laser thermal radiation image are fused and superimposed to generate an image containing the overall thermal radiation information of the surface of the carbon fiber composite material and the detailed information of the defects. The laser thermal imaging detects and positions the distribution position of the surface defects of the carbon fiber composite material, the laser excitation ultrasonic field imaging detects the specific length, width and depth size information of the defects, the laser ultrasonic image contains the distribution and specific size information of the surface defects of the carbon fiber composite material, and the "thermal radiation-ultrasonic excitation" fusion image contains the overall thermal radiation information of the surface of the carbon fiber composite material and the detailed information of the defects.

[0087] The present application detects the defect position distribution and size information of the surface of the carbon fiber composite material by using the image recognition method of laser "thermal radiation-ultrasonic excitation" imaging fusion, and is a new type of composite material surface defect detection method. In addition, the composite material defect detection system provided by the present application creatively uses a single laser source according to the "fast-slow" combination mode of the thermal radiation "fast" positioning and the ultrasonic excitation "precise" imaging, can realize the rapid, efficient, non-destructive, non-contact and visualized detection of defects of various materials, and can be applied to the efficient and high-quality detection of the surface defects of the carbon fiber composite material.

[0088] The various embodiments described in this specification are presented for the purpose of illustrating the principles of the application and its best mode of operation. Each of the embodiments described in this specification are presented for the purpose of illustrating the various aspects of the application, and the embodiments are not intended to limit the scope of the application.

[0089] The principles and operation of the present application are explained further with reference to the accompanying drawings. While the present application has been described herein before with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, further whereby it will be apparent that the application can be adapted to other and different applications and forms without departing from the spirit thereof and without exceeding the scope of the disclosed subject matter. Accordingly, other implementations are within the scope of the following claims.

Claims

1. A composite material defect detection system, characterized in that: The system includes: a pulse laser, an infrared thermal imager, a photoelectric detection device and a host computer; The pulse laser is connected to the host computer and is used to emit a first laser to the surface of the composite material according to a first laser parameter sent by the host computer, and emit a second laser to the defects on the surface of the composite material according to a second laser parameter sent by the host computer; the first laser parameter and the second laser parameter both include laser energy density, scanning speed and scanning path; The infrared thermal imager is connected to the host computer and is used to monitor the temperature field of the surface of the composite material scanned by the first laser and transmit the collected thermal radiation image to the host computer; The photoelectric detection device is connected to the host computer and is used to monitor, convert and demodulate the ultrasonic waves generated by the second laser scanning the defects on the surface of the composite material, and transmit the demodulated laser ultrasonic image of the defect to the host computer; The host computer is used to determine the first laser parameter according to the characteristics of the composite material and send the first laser parameter to the pulse laser, obtain the defect position of the composite material according to the thermal radiation image, and determine the second laser parameter according to the defect position and the characteristics of the composite material and send the second laser parameter to the pulse laser. It is also used to fuse and superimpose the defect laser ultrasound image and the thermal radiation image, and determine the defect information of the composite material based on the fused and superimposed images; the defect information includes the defect position, defect length, defect width and defect depth.

2. The composite material defect detection system according to claim 1, characterized in that: The host computer includes a control module and an image fusion processing module; The control module is connected to the pulse laser and is used to determine the first laser parameter according to the characteristics of the composite material and send it to the pulse laser, and to determine the second laser parameter according to the defect position and the characteristics of the composite material and send it to the pulse laser; The image fusion processing module is respectively connected to the control module, the infrared thermal imager and the photoelectric detection device, and is used to obtain the defect position of the composite material based on the received thermal radiation image, and send the defect position to the control module, and fuse and superimpose the defect laser ultrasonic image and the thermal radiation image, and determine the defect information of the composite material based on the fused and superimposed images.

3. The composite material defect detection system according to claim 2, characterized in that: The host computer also includes a display terminal; The display terminal is connected to the image fusion processing module and is used to display the defect laser ultrasonic image, the thermal radiation image, the fused and superimposed image, the defect position of the composite material and the defect information of the composite material.

4. The composite material defect detection system according to claim 1, characterized in that: The photoelectric detection device includes a photoelectric detector, an ultrasonic detection tracker and an interferometer; The ultrasonic detection tracker is used to monitor ultrasonic waves generated by the second laser scanning the defects on the surface of the composite material; The photoelectric detector is connected to the ultrasonic detection tracker and is used to follow the movement of the ultrasonic wave detected by the ultrasonic detection tracker and receive the ultrasonic wave, and convert the received ultrasonic wave into optical information; The interferometer is connected to the photoelectric detector and the host computer respectively, and is used to receive the optical information, demodulate the ultrasonic wave according to the optical information, and transmit the defect laser ultrasonic image obtained after demodulation to the host computer.

5. The composite material defect detection system according to claim 1, characterized in that: The system also includes a lens; The lens is arranged on the optical path of the first laser and the second laser, and is used to focus the first laser and the second laser; the first laser and the second laser are irradiated on the surface of the composite material through the lens.

6. The composite material defect detection system according to claim 1, characterized in that: The pulse laser is a nanosecond laser, a picosecond laser or a femtosecond laser.

7. The composite material defect detection system according to claim 1, characterized in that: The average power of the pulse laser is greater than 50W.

8. The composite material defect detection system according to claim 1, characterized in that: The infrared thermal imager is a general-purpose industrial infrared thermal imager.

9. A composite material defect detection method, applied to the composite material defect detection system according to any one of claims 1 to 8, characterized in that: The method comprises: Determining first laser parameters according to the characteristics of the composite material, and sending the first laser parameters to the pulsed laser; the first laser parameters include laser energy density, scanning speed, and scanning path; Acquire a thermal radiation image obtained by scanning the surface of the composite material using the first laser parameter; determining defect locations on the surface of the composite material according to the thermal radiation image; Determining second laser parameters according to the defect location and the characteristics of the composite material, and sending the second laser parameters to the pulsed laser; the second laser parameters include laser energy density, scanning speed, and scanning path; Obtaining a defect laser ultrasonic image obtained by scanning defects on the surface of the composite material using the second laser parameter; The defect laser ultrasonic image and the thermal radiation image are fused and superimposed to determine the defect information of the surface of the composite material; the defect information includes the defect position, defect length, defect width and defect depth.

10. The composite material defect detection method according to claim 9, characterized in that: The method further comprises: The defect laser ultrasonic image, the thermal radiation image, the fused and superimposed image, the defect position of the composite material and the defect information of the composite material are visually displayed.

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