Hydraulic tunnel operation period concrete crack inspection system and test method thereof

Abstract

The invention discloses a hydraulic tunnel operation period concrete crack inspection system and a test method thereof, and relates to the field of hydraulic tunnel operation period concrete crack detection, the system comprises a power box and a master control box, the power box and the master control box are connected through a balancing stand, the power box comprises a hydraulic cylinder and a sliding pulley, and the hydraulic cylinder is connected with the master control box through a hydraulic cylinder. The main control box comprises a three-dimensional laser scanner and an infrared thermal imager which are arranged at the bottom of the main control box, an environment monitoring unit and a camera which are arranged on the front side of the main control box, and a communication unit, a storage unit, a control unit and a power supply unit which are arranged in the main control box. Aiming at the limitations of low detection efficiency, manual intervention and the like of concrete cracks in the operation period of the hydraulic tunnel, a three-dimensional laser scanning technology and an infrared thermal imaging technology are simultaneously used, and an image processing algorithm and an artificial intelligence technology are integrated, so that the functions of automatically processing data and extracting key parameters such as crack positions and sizes are realized; the inspection test of the concrete crack in the operation period of the hydraulic tunnel is completed.

Description

Technical Field

[0001] This invention relates to the field of concrete crack detection technology during the operation of hydraulic tunnels, and in particular to a concrete crack inspection system and testing method for hydraulic tunnels during the operation period. Background Technology

[0002] As crucial infrastructure, the monitoring and assessment of the structural integrity of hydraulic tunnels are essential for their safe operation. In monitoring the structural integrity of hydraulic tunnels, the detection of concrete cracks is of paramount importance in protecting tunnel safety, reducing maintenance costs, ensuring structural integrity, and guaranteeing the operation of water conservancy projects. Timely detection and identification of concrete cracks can prevent structural strength degradation and potential accidents, effectively reduce maintenance costs and extend service life, while maintaining the reliability and stability of the tunnel to ensure its normal operation and the smooth progress of water conservancy projects. However, traditional crack detection methods suffer from complex operation and low detection efficiency. Therefore, there is an urgent need for the development and application of an efficient and accurate concrete crack inspection system and testing methods for hydraulic tunnels.

[0003] Three-dimensional laser scanning technology can quickly acquire geometric data inside tunnels, accurately present the tunnel's structural morphology, and generate precise three-dimensional panoramic models, providing a reliable foundation for concrete crack detection. Infrared thermal imaging technology, on the other hand, can analyze the temperature distribution of an object's surface by measuring its thermal radiation, thereby detecting potential cracks or hot spots. This non-contact thermal imaging technology is highly efficient and accurate, and can be widely used for the detection and assessment of concrete cracks inside tunnels. Therefore, combining three-dimensional laser scanning with infrared thermal imaging technology to achieve fully automated crack detection can bring significant technological advantages and convenience to concrete crack detection during the operational phase of hydraulic tunnels. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a concrete crack inspection system and testing method for hydraulic tunnels during operation, enabling fully automated, non-contact scanning and automatic data processing for result evaluation. This system utilizes three-dimensional laser scanning and infrared thermal imaging technologies to efficiently acquire a three-dimensional panoramic model of the interior of hydraulic tunnels. By analyzing the geometric morphology and thermal radiation characteristics of the cracks, it achieves accurate detection and assessment of concrete cracks.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a concrete crack inspection system for hydraulic tunnel operation period, including a power box (1) and a main control box (2). The bottom of the power box (1) is connected to the top of the main control box (2) through a balance platform (5). The bottom of the main control box (2) is equipped with a three-dimensional laser scanner (3) and an infrared thermal imaging detector (4) with the same horizontal height.

[0006] As a further improvement of the present invention, the top of the power box (1) is provided with an inverted "T" shaped groove, which is used to cooperate with the inverted "T" shaped track to make the system move along a specified path; the inverted "T" shaped groove of the power box (1) is provided with a transmission pulley (6) and a hydraulic cylinder (7), wherein the transmission pulley (6) is powered by the hydraulic cylinder (7).

[0007] As a further improvement of the present invention, an environmental monitoring unit (8) and a camera (9) are embedded in the front side of the main control box (2). The three-dimensional laser scanner (3) and the infrared thermal imaging detector (4) are both connected to the bottom of the main control box (2) through a stabilizing platform (10). The three-dimensional laser scanner (3) is connected to the stabilizing platform (10) through a rotating connecting rod (11). The rotating connecting rod (11) is used to realize the 360° horizontal rotation of the three-dimensional laser scanner (3). The infrared thermal imaging detector (4) is connected to the stabilizing platform (10) through a fixed connecting rod (12).

[0008] As a further improvement of the present invention, the bottom surface inside the main control box (2) is provided with a communication unit (13), a storage unit (14), a control unit (15) and a power supply unit (16) located inside the protective shell.

[0009] As a further improvement of the present invention, the control unit (15) includes a PLC control chip, a positioning chip, and an artificial intelligence chip, which are used to generate control commands based on the data obtained by the three-dimensional laser scanner (3), infrared thermal imaging detector (4), environmental monitoring unit (8), and camera (9), control the operation of the concrete crack inspection system during the operation period of the hydraulic tunnel, and complete the automatic processing of the collected data to realize the movement of the inspection section of the hydraulic tunnel and the fully automatic detection of concrete cracks.

[0010] As a further improvement of the present invention, the power supply unit (16) is used to provide power to the three-dimensional laser scanner (3), the infrared thermal imaging detector (4), the environmental monitoring unit (8), the camera (9), the communication unit (13), the storage unit (14) and the control unit (15).

[0011] As a further improvement of the present invention, both the power box (1) and the main control box (2) are provided with protective shells, and both are fixedly connected and sealed by bolts.

[0012] This invention also provides a method for inspecting and testing concrete cracks during the operation of hydraulic tunnels, which is implemented using the concrete crack inspection system for hydraulic tunnels during operation as described above. The method includes the following steps:

[0013] S1. Install an inverted "T" shaped track suitable for the top slot of the power box (1) at the arch of the hydraulic tunnel inspection section. Install the concrete crack inspection system of the hydraulic tunnel during operation on the track. Fix the power box (1) to the installation track through the slot on the top of the power box (1) and the transmission pulley (6). Import the inspection path into the control unit (15) and cooperate with the power supply unit (16), transmission pulley (6) and hydraulic cylinder (7) to realize the movement on the laid track. During the movement, the environmental monitoring unit (8) and the camera (9) perceive the inspection environment, judge the working environment status, and assist the system in controlling the movement path. At the same time, the three-dimensional laser scanner (3) and the infrared thermal imaging detector (4) collect data during the movement.

[0014] S2. The point cloud data obtained by the 3D laser scanner (3) and the thermal imaging data obtained by the infrared thermal imaging detector (4) are input into the control unit (15). The artificial intelligence chip in the unit automatically reads and performs data preprocessing such as positioning, filtering and splicing of the point cloud data and thermal imaging data. The processed data is then transmitted to the back-end server through the communication unit (13) to complete the identification and information extraction of concrete cracks in the data. After summarizing, the final test results of concrete cracks in the test section are output.

[0015] As a further improvement of the present invention, step S2 specifically includes the following steps:

[0016] S201. The preprocessed point cloud data is clustered based on the density distribution function using the DENCLUE algorithm. Since the point cloud density is basically uniform in smooth concrete areas, while the point cloud density is significantly increased in areas with cracks due to unevenness, the identification of concrete cracks is achieved. Specifically, the Gaussian kernel function is selected as the influence function for estimating the contribution of data points.

[0017] ;

[0018] in, For the influence function, This is a bandwidth parameter that controls the decay rate of the influence function;

[0019] Define the density function as:

[0020] ;

[0021] in, Let n be the density function, and n be the total number of points in the dataset. It refers to each point in the dataset;

[0022] The gradient guiding the selection of cluster centers is:

[0023] ;

[0024] S202. The preprocessed thermal imaging data is used to identify concrete cracks based on temperature differences using the Canny edge detection algorithm. First, Gaussian filtering is applied to remove noise from the thermal imaging data. Non-edge areas with weak texture are smoothed to obtain more accurate edges. Then, the gradient magnitude and direction in the thermal imaging data are calculated to determine the edges, using the Sobel operator.

[0025] ;

[0026] ;

[0027] ;

[0028] in, The convolution kernel with Gaussian weights is obtained by passing thermal imaging data through a Gaussian filter. The horizontal convolution kernel of the Sobel filter. The convolution kernel in the vertical direction of the Sobel filter. The magnitude of the gradient. The direction of the gradient;

[0029] After acquiring the gradient magnitude and gradient direction of the data, non-maximum suppression is applied to the image edges based on the results to remove most non-edge points. Then, a dual thresholding technique is applied to automatically determine the edges by selecting strong and weak thresholds, thereby realizing the automatic identification of potential locations of concrete cracks based on thermal imaging data.

[0030] S203. Based on the judgment results from the combined point cloud data and thermal imaging data, extract the corresponding crack data with the same location from the two results to complete the automatic identification of concrete cracks during the operation period of hydraulic tunnels, extract their corresponding location and size, and automatically generate test results.

[0031] The beneficial effects of this invention are:

[0032] 1. This invention addresses the limitations of traditional concrete crack detection in hydraulic tunnels, such as low detection efficiency and manual intervention. By introducing three-dimensional laser scanning technology and infrared thermal imaging technology, it achieves fully automatic, high-efficiency, and non-contact scanning, significantly improving detection efficiency and accuracy while reducing labor costs.

[0033] 2. The application of three-dimensional laser scanning technology and infrared thermal imaging technology in the detection of concrete cracks in hydraulic tunnels during operation demonstrates advantages that traditional detection technologies do not possess, such as automation, efficiency, and non-contact. However, the cumbersome data processing and the inherent limitations of each technology in the operation of hydraulic tunnels hinder the realization of crack inspection. This invention, by simultaneously using both technologies and combining image processing algorithms with artificial intelligence, enables the system to automatically process data and extract key parameters such as crack location and size, providing an important basis for subsequent structural evaluation. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the inspection system in an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the power box structure in an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the main control box in an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of the internal structure of the main control box in an embodiment of the present invention;

[0038] Figure 5 This is a flowchart illustrating the operation of the inspection system in an embodiment of the present invention.

[0039] Figure 6 This is a schematic diagram of a concrete crack inspection system for hydraulic tunnels during operation, as shown in an exemplary embodiment of the present invention.

[0040] Figure label:

[0041] 1-Power box, 2-Main control box, 3-3D laser scanner, 4-Infrared thermal imaging detector, 5-Balance platform, 6-Transmission pulley, 7-Hydraulic cylinder, 8-Environmental monitoring unit, 9-Camera, 10-Stabilizing platform, 11-Rotating connecting rod, 12-Fixed connecting rod, 13-Communication unit, 14-Storage unit, 15-Control unit, 16-Power supply unit. Detailed Implementation

[0042] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0043] Example

[0044] like Figure 1 , Figure 5 and Figure 6As shown, a concrete crack inspection system for hydraulic tunnels during operation includes a power box 1, a main control box 2, a 3D laser scanner 3, an infrared thermal imaging detector 4, and a balance platform 5. The bottom of the power box 1 is connected to the top of the main control box 2 via the balance platform 5 to maintain the balance of the concrete crack inspection system during the operation of the hydraulic tunnel. The power box 1, the main control box 2, and the balance platform 5 are vertically connected and their centers are on the same central axis. The 3D laser scanner 3 and the infrared thermal imaging detector 4 are distributed at the same distance on the left and right sides of the bottom of the main control box 2 and have the same horizontal height.

[0045] Furthermore, such as Figure 2 As shown, the power box 1 has an inverted "T" shaped groove at the top center line, which is used to cooperate with the inverted "T" shaped track to make the system move along a specified path; the inverted "T" shaped groove of the power box 1 also includes a transmission pulley 6 and a hydraulic cylinder 7 fixedly connected to the top surface of the groove, wherein the transmission pulley 6 is powered by the hydraulic cylinder 7; the power box 1 is provided with a protective shell, which is fixedly connected and sealed by bolts.

[0046] Furthermore, such as Figure 3 As shown, the main control box 2 also includes an environmental monitoring unit 8 and a camera 9 located on the front side of the main control box 2, and a stabilizing platform 10, a 3D laser scanner 3, and an infrared thermal imaging detector 4 located at the bottom of the main control box 2. The front side of the main control box 2 has corresponding grooves for the sensor part of the environmental monitoring unit 8 and the lens part of the camera 9, and the interior is fixedly connected to the remaining parts of the environmental monitoring unit 8 and the camera 9. The bottom of the main control box 2 is fixedly connected to the stabilizing platform 10. The 3D laser scanner 3 is connected to the stabilizing platform 10 through a rotating connecting rod 11, and the infrared thermal imaging detector 4 is connected to the stabilizing platform 10 through a fixed connecting rod 12. The rotating connecting rod 11 can enable the 3D laser scanner 3 to rotate 360° horizontally to ensure panoramic scanning of the entire hydraulic tunnel. The fixed connecting rod 12 is fixedly connected to the infrared thermal imaging detector 4. The stabilizing platform 10 can ensure the stability of the 3D laser scanner 3 and the infrared thermal imaging detector 4 during the system's movement. The main control box 2 is equipped with a protective shell, which is fixedly connected and sealed by bolts.

[0047] Furthermore, such as Figure 4As shown, the main control box 2 also includes a communication unit 13, a storage unit 14, a control unit 15, and a power supply unit 16 disposed on the inner bottom surface. The communication unit 13, storage unit 14, control unit 15, and power supply unit 16 include protective shells for encapsulation and fixed connection to the inner bottom surface of the main control box. The control unit 15 includes a PLC control chip, a positioning chip, and an artificial intelligence chip, used to generate control commands based on the data obtained by the 3D laser scanner 3, infrared thermal imaging detector 4, environmental monitoring unit 8, and camera 9, to control the operation of the concrete crack inspection system during the operation period of the hydraulic tunnel, and to complete the processing of the collected data, so as to realize the movement of the inspection section of the hydraulic tunnel and the fully automatic detection of concrete cracks. The power supply unit 16 is connected to the 3D laser scanner 3, infrared thermal imaging detector 4, environmental monitoring unit 8, camera 9, communication unit 13, storage unit 14, and control unit 15 through cables and provides them with power.

[0048] Furthermore, a preferred embodiment of the above-described embodiments is proposed, specifically, a method for installing a concrete crack inspection system during the operation of a hydraulic tunnel, comprising:

[0049] Inspection route confirmation: The system travels along a linear track during inspection. Therefore, the inspection route should be confirmed based on the distribution area of ​​concrete to be tested during the operation of the hydraulic tunnel. At the same time, an exit route should be planned based on the relationship between the testing area and the tunnel entrance, so that the inspection system can leave the tunnel for maintenance, charging, etc. during non-working periods.

[0050] Track laying and system installation: The system should be installed in the inverted "T" shaped track in the slot at the top of the power box 1. Appropriate tracks should be laid at the arch according to the size of the hydraulic tunnel to ensure that they can support the operation of the system. After the track laying is completed, the system should be installed on the track according to the inverted "T" shaped groove track at the top of the power box 1, while ensuring that the system can operate normally on the track.

[0051] Furthermore, as a preferred implementation scheme, a method for inspecting and testing concrete cracks during the operation of hydraulic tunnels is proposed. This method specifically includes the following steps:

[0052] S1. Install an inverted "T"-shaped track at the arch of the inspection section of the hydraulic tunnel, which is suitable for the top slot of the power box 1. Install the concrete crack inspection system for the operation period of the hydraulic tunnel onto the track. The power box and the installation track are fixed by the slot on the top of the power box 1 and the transmission pulley. The inspection path is imported into the control unit and moved on the track in conjunction with the power supply unit 16, the transmission pulley 6 and the hydraulic cylinder 7. During the movement, the inspection environment is perceived by the environmental monitoring unit 8 and the camera 9, the working environment status is judged, and the system controls the movement path. At the same time, the three-dimensional laser scanner 3 and the infrared thermal imaging detector 4 collect data during the movement.

[0053] S2. The point cloud data acquired by the 3D laser scanner 3 and the thermal imaging data acquired by the infrared thermal imaging detector 4 are input to the control unit 15. The artificial intelligence chip therein automatically reads and performs data preprocessing such as positioning, filtering and stitching on the point cloud data and thermal imaging data. Then, the processed data is transmitted to the back-end server through the communication unit 13 to complete the identification and information extraction of concrete cracks in the data. After summarizing, the final test results of concrete cracks in the test section are output.

[0054] Furthermore, in step S2, the specific process for performing crack identification testing on the preprocessed point cloud data and thermal imaging data includes the following steps:

[0055] S201. The preprocessed point cloud data is clustered based on the density distribution function using the DENCLUE algorithm. Since the point cloud density is basically uniform in smooth concrete areas, while the point cloud density is significantly increased in areas with cracks due to unevenness, the concrete cracks can be identified. Specifically, the Gaussian kernel function is selected as the influence function for estimating the contribution of data points.

[0056]

[0057] Among them, the As the influence function, the This is a bandwidth parameter that controls the decay rate of the influence function;

[0058] The density function is defined as follows:

[0059]

[0060] Among them, the Let n be the density function, where n is the total number of points in the dataset. It refers to each point in the dataset;

[0061] The gradient guiding the selection of cluster centers is:

[0062]

[0063] S202. The preprocessed thermal imaging data is used to identify concrete cracks based on temperature differences using the Canny edge detection algorithm. Since the overall temperature distribution of concrete in operational hydraulic tunnels is relatively uniform, but water seepage occurs at crack locations, resulting in locally lower temperatures, this method is used to identify cracks in the thermal imaging data. Specifically, Gaussian filtering is first applied to remove noise from the thermal imaging data, and non-edge areas with weak textures are smoothed to obtain more accurate edges. Then, the gradient magnitude and gradient direction in the thermal imaging data are calculated to determine the edges. In this step, the Sobel operator is used for calculation.

[0064]

[0065]

[0066]

[0067] in, The convolution kernel with Gaussian weights is obtained by passing thermal imaging data through a Gaussian filter. The horizontal convolution kernel of the Sobel filter. The convolution kernel in the vertical direction of the Sobel filter. The magnitude of the gradient. The direction of the gradient;

[0068] After acquiring the gradient magnitude and gradient direction of the data, non-maximum suppression is applied to the image edges based on the results to remove most non-edge points. Then, a dual thresholding technique is applied to automatically determine the edges by selecting strong and weak thresholds, thereby realizing the automatic identification of potential locations of concrete cracks based on thermal imaging data.

[0069] S203. Based on the judgment results from the combined point cloud data and thermal imaging data, extract the corresponding crack data with the same location from both results, complete the automatic identification of concrete cracks during the operation period of hydraulic tunnels, extract their corresponding location and size, and automatically generate test results.

[0070] After the installation of the system in this embodiment is completed, the control unit and communication unit of the system need to be debugged through trial operation so that the system's data acquisition, data processing and crack identification can be completed in cooperation among the various units, ensuring the normal operation of concrete crack identification and inspection.

[0071] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A concrete crack inspection system for hydraulic tunnels during operation, characterized in that, It includes a power box (1) and a main control box (2). The bottom of the power box (1) is connected to the top of the main control box (2) via a balance platform (5). The bottom of the main control box (2) is equipped with a three-dimensional laser scanner (3) and an infrared thermal imaging detector (4) with the same horizontal height.

2. The concrete crack inspection system for hydraulic tunnels during operation according to claim 1, characterized in that, The top of the power box (1) is provided with an inverted "T" shaped groove, which is used to cooperate with the inverted "T" shaped track to make the system move along a specified path; the inverted "T" shaped groove of the power box (1) is provided with a transmission pulley (6) and a hydraulic cylinder (7), wherein the transmission pulley (6) is powered by the hydraulic cylinder (7).

3. The concrete crack inspection system for hydraulic tunnels during operation according to claim 1, characterized in that, An environmental monitoring unit (8) and a camera (9) are embedded in the front of the main control box (2). The three-dimensional laser scanner (3) and the infrared thermal imaging detector (4) are both connected to the bottom of the main control box (2) through a stabilizing platform (10). The three-dimensional laser scanner (3) is connected to the stabilizing platform (10) through a rotating connecting rod (11). The rotating connecting rod (11) is used to realize the 360° horizontal rotation of the three-dimensional laser scanner (3). The infrared thermal imaging detector (4) is connected to the stabilizing platform (10) through a fixed connecting rod (12).

4. The concrete crack inspection system for hydraulic tunnels during operation according to claim 3, characterized in that, The bottom surface inside the main control box (2) is provided with a communication unit (13), a storage unit (14), a control unit (15) and a power supply unit (16) located inside the protective shell.

5. The concrete crack inspection system for hydraulic tunnels during operation according to claim 4, characterized in that, The control unit (15) includes a PLC control chip, a positioning chip, and an artificial intelligence chip. It is used to generate control commands based on the data obtained by the three-dimensional laser scanner (3), infrared thermal imaging detector (4), environmental monitoring unit (8), and camera (9), to control the operation of the concrete crack inspection system during the operation period of the hydraulic tunnel, and to complete the automatic processing of the collected data, so as to realize the movement of the inspection section of the hydraulic tunnel and the fully automatic detection of concrete cracks.

6. The concrete crack inspection system for hydraulic tunnels during operation, as described in claim 4, is characterized in that... The power supply unit (16) is used to provide power to the three-dimensional laser scanner (3), infrared thermal imaging detector (4), environmental monitoring unit (8), camera (9), communication unit (13), storage unit (14) and control unit (15).

7. The concrete crack inspection system for hydraulic tunnels during operation according to claim 1, characterized in that, Both the power box (1) and the main control box (2) are equipped with protective shells, and are fixed and sealed by bolts.

8. A method for inspecting and testing concrete cracks during the operation of a hydraulic tunnel, characterized in that, The method employs the concrete crack inspection system for hydraulic tunnels during operation as described in any one of claims 1-7, and includes the following steps: S1. Install an inverted "T" shaped track suitable for the top slot of the power box (1) at the arch of the hydraulic tunnel inspection section. Install the concrete crack inspection system of the hydraulic tunnel during operation on the track. Fix the power box (1) to the installation track through the slot on the top of the power box (1) and the transmission pulley (6). Import the inspection path into the control unit (15) and cooperate with the power supply unit (16), transmission pulley (6) and hydraulic cylinder (7) to realize the movement on the laid track. During the movement, the environmental monitoring unit (8) and the camera (9) perceive the inspection environment, judge the working environment status, and assist the system in controlling the movement path. At the same time, the three-dimensional laser scanner (3) and the infrared thermal imaging detector (4) collect data during the movement. S2. The point cloud data obtained by the 3D laser scanner (3) and the thermal imaging data obtained by the infrared thermal imaging detector (4) are input into the control unit (15). The artificial intelligence chip in the unit automatically reads and performs data preprocessing such as positioning, filtering and splicing of the point cloud data and thermal imaging data. The processed data is then transmitted to the back-end server through the communication unit (13) to complete the identification and information extraction of concrete cracks in the data. After summarizing, the final test results of concrete cracks in the test section are output.

9. The method for inspecting and testing concrete cracks during the operation period of a hydraulic tunnel according to claim 8, characterized in that, Step S2 specifically includes the following steps: S201. The preprocessed point cloud data is clustered based on the density distribution function using the DENCLUE algorithm. Since the point cloud density is basically uniform in smooth concrete areas, while the point cloud density is significantly increased in areas with cracks due to unevenness, the identification of concrete cracks is achieved. Specifically, the Gaussian kernel function is selected as the influence function for estimating the contribution of data points. ； in, For the influence function, This is a bandwidth parameter that controls the decay rate of the influence function; Define the density function as: ； in, Let n be the density function, and n be the total number of points in the dataset. It refers to each point in the dataset; The gradient guiding the selection of cluster centers is: ； S202. The preprocessed thermal imaging data is used to identify concrete cracks based on temperature differences using the Canny edge detection algorithm. First, Gaussian filtering is applied to remove noise from the thermal imaging data. Non-edge areas with weak texture are smoothed to obtain more accurate edges. Then, the gradient magnitude and direction in the thermal imaging data are calculated to determine the edges, using the Sobel operator. ； ； ； in, The convolution kernel with Gaussian weights, obtained by applying a Gaussian filter to thermal imaging data, is a convolution kernel whose weights have a Gaussian distribution. The horizontal convolution kernel of the Sobel filter. The convolution kernel in the vertical direction of the Sobel filter. The magnitude of the gradient. The direction of the gradient; After acquiring the gradient magnitude and gradient direction of the data, non-maximum suppression is applied to the image edges based on the results to remove most non-edge points. Then, a dual thresholding technique is applied to automatically determine the edges by selecting strong and weak thresholds, thereby realizing the automatic identification of potential locations of concrete cracks based on thermal imaging data. S203. Based on the judgment results from the combined point cloud data and thermal imaging data, extract the corresponding crack data with the same location from the two results to complete the automatic identification of concrete cracks during the operation period of hydraulic tunnels, extract their corresponding location and size, and automatically generate test results.

Images