A railway bridge surface crack automatic detection robot and detection method

Abstract

The present invention discloses a railway bridge surface crack automatic detection robot and detection method. The robot comprises a control device, an image acquisition device, a driving device for driving the image acquisition device to move vertically and horizontally, and a suspension device for driving the driving device to flip to the lower side of the bridge and hang and fix it to the bridge railing; the control device is electrically connected to the image acquisition device, the driving device and the suspension device. When in use, the driving device can be quickly and conveniently flipped to the lower side of the bridge and fixed through the suspension device, and then the image acquisition device is driven to move vertically and horizontally in combination with the driving device, so as to realize the automatic acquisition of the width distribution, length distribution, angle distribution and area distribution of the bottom surface crack of the railway bridge, and effectively improve the detection efficiency and accuracy of the bridge surface crack.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge detection, and in particular to a detection device and method for improving the safety of railway bridges and the accuracy of damage assessment, and specifically to a railway bridge surface crack automatic detection robot and detection method. Background Art

[0002] Heavy-haul railways have large transport capacity and significant economic and social benefits. The development of heavy-haul railway transportation has become the direction of railway transportation development in countries around the world.

[0003] Surface cracks on bridges are a direct manifestation of concrete structural deterioration and affect the safety, serviceability and durability of bridge structures. Most studies on concrete structures consider cracks as an important factor in the decision-making process and relate detailed crack patterns of concrete beams and panels to quantitative damage states at different loading stages. Crack detection is a basic task to check the health of bridge structures. For heavy-duty railway beam bridges, they are subjected to high-frequency and high-level loads for a long time, and load has become the main influencing factor for the deterioration of this type of bridge. Since the bottom surface of heavy-duty railway beam bridges is subjected to the largest tensile stress, the initial cracks and the widest cracks are often located on the bottom surface of the bridge. Therefore, the accurate detection and quantification of detailed cracks on the bottom surface of heavy-duty railway bridges is of great significance for evaluating the safety and damage degree of bridge structures.

[0004] Heavy-duty railways adopt a closed operation mode, so operation inspection and maintenance can only be carried out during the window period. In order to ensure the normal use function of the bridge and extend its service life, a more efficient, accurate and intelligent technology is needed to conduct daily inspections of the bridge. At present, the more advanced inspection robots in bridge engineering include bridge inspection vehicles, inspection drones, rock climbing robots, climbing robots, wall climbing robots based on duct fans, and robots based on grippers. Affected by the structural form and working conditions of railway bridges, these inspection robots have certain limitations.

[0005] (1) Although inspection drones have improved the intelligence of inspections and reduced the difficulty of detection to a certain extent, they still have problems such as weak wind resistance, poor stability, and low positioning accuracy. In addition, drones themselves are limited by safety distances, making it difficult to identify microcracks and accurately quantify cracks.

[0006] (2) Rock climbing robots usually use magnetic force or negative pressure suction to adhere to the surface, but for bridges built of concrete, it is not regular and smooth enough to ensure good adhesion.

[0007] (3) Climbing robots, ducted fan-based wall-climbing robots, and gripper-based robots. Although these robots can work on vertical walls, they cannot walk on the bottom of bridges, which limits their detection of cracks on the bottom of bridges. Since the bottom of railway beam bridges is subjected to the greatest tensile stress, the initial cracks and the widest cracks are often located on the bottom of bridges.

[0008] (4) Bridge inspection vehicles require a high degree of freedom robotic arm to complete crack inspection on the bottom of the bridge, which places high technical requirements on operators and reduces the efficiency of crack inspection. In addition, bridge inspection vehicles are often large in size. Since special maintenance vehicles will pass by during the window period, the inspection system must be installed in the railway drainage ditch. Due to the limitation of the width of the railway bridge drainage ditch, it is difficult to perform crack inspection on the railway bridge. Summary of the invention

[0009] In view of this, the purpose of the present invention is to provide a railway bridge surface crack automatic detection robot and detection method, so as to improve the efficiency and accuracy of detection on the basis of realizing automated and intelligent detection.

[0010] According to the first aspect of the present application, a robot for automatic detection of cracks on the surface of a railway bridge is provided, comprising a control device, an image acquisition device, an image post-processing system, a drive device for driving the image acquisition device to move vertically and horizontally, and a suspension device for driving the drive device to flip to the lower side of the bridge and hang it on the bridge railing; the image post-processing system is electrically connected to the image acquisition device to form an execution device, and the image post-processing system includes a hardware device capable of running the developed software. It also includes a power supply device, which includes a mobile power supply, and the power supply device is respectively connected to the control device, the suspension device, the drive device and the execution device. Specifically, the power supply device is connected to the control device; the power supply device is connected to the motor in the suspension device; the power supply device is connected to the motor in the drive device; the power supply device is connected to the camera in the execution device and the camera fill light device.

[0011] The control device is electrically connected to the image acquisition device, the drive device and the suspension device; specifically, the control device includes a suspension device control unit, a drive device control unit and an image acquisition device control unit; the suspension device control unit and the drive device control unit have programming capabilities. The suspension device control unit is connected to the upper and lower motors in the suspension device; the drive device control unit is connected to the motor in the drive device; the image acquisition device controller is connected to the camera in the execution device to control the camera shooting frequency, and the control device is placed in the safe area at both ends of the railway bridge.

[0012] Furthermore, the suspension device includes suspension components distributed on both sides, and the suspension components include a fixed rod, a mechanical arm and a driving device support rod. The top of the mechanical arm is connected to the fixed rod, and the bottom is rotatably hinged with the driving device support rod through a mechanical arm rotation joint; an upper drive shaft driven to rotate by an upper motor is installed across the tops of the two mechanical arms, and pulleys are installed at both ends of the upper drive shaft, and a driving rope is wound around the pulley, and the free end of the driving rope is connected to the driving device support rod on the corresponding side; a lower drive shaft driven to rotate by a lower motor is connected across the rotating joints of the mechanical arms on both sides. During implementation, the upper motor pulls the mechanical arm to rotate, and the lower motor drives the driving device support rod to rotate relative to the mechanical arm rotation joint, so that the driving device support rod can be expanded or retracted.

[0013] Furthermore, a rope limiting groove is provided on the mechanical arm.

[0014] Furthermore, the driving device includes a longitudinal transmission mechanism arranged on both sides and a transverse transmission mechanism connected across the execution end of the longitudinal transmission mechanism, and the longitudinal transmission mechanism and the transverse transmission mechanism are driven by a longitudinal transmission motor and a transverse transmission motor respectively.

[0015] Furthermore, two ends of the longitudinal transmission mechanisms on both sides are respectively cross-connected with a first transmission shaft and a second transmission shaft.

[0016] Furthermore, the image acquisition device includes an image acquisition device base installed at the execution end of the transverse transmission mechanism, and a camera and a camera fill light device installed on the image acquisition device base.

[0017] Furthermore, a rope fixing device is provided on the support rod of the driving device, and the free end of the driving rope is connected to the rope fixing device.

[0018] Furthermore, the rope fixing device includes a fixed shaft fixedly connected to the driving device support rod, a rotating ring rotatably sleeved with the fixed shaft, and a limit plate arranged at the outer end of the fixed shaft, and the free end of the driving rope is connected to the rotating ring.

[0019] According to a second aspect of the present application, there is provided a method for automatically detecting surface cracks of a railway bridge using the above robot, comprising the following steps:

[0020] S1: deploy the driving device and the image acquisition device to the lower side of the railway bridge through the suspension device, and hang and fix the suspension device to the bridge railing;

[0021] S2: starting the driving device and the image acquisition device, and driving the image acquisition device to move vertically and horizontally through the driving device to automatically complete the scanning and shooting of the cracks on the bottom surface of the railway bridge;

[0022] S3: Start the image post-processing system, synthesize the panoramic image of the bottom surface of the railway bridge based on the image stitching algorithm, identify the cracks in the panoramic image based on the deep learning algorithm, and quantify the cracks on the bottom surface of the bridge based on the crack automatic quantification algorithm;

[0023] S4: Output a panoramic image of the cracks on the bottom surface of the railway bridge, output the width distribution, length distribution, angle distribution and area distribution of the cracks on the bottom surface of the railway bridge, and complete a railway bridge crack detection.

[0024] Beneficial effects of the present invention:

[0025] The present invention provides a railway bridge surface crack automatic detection robot and detection method, the robot includes a control device, an image acquisition device, a driving device for driving the image acquisition device to move vertically and horizontally, and a suspension device for driving the driving device to flip to the lower side of the bridge and hang it with the bridge railing; the control device is electrically connected to the image acquisition device, the driving device and the suspension device. When used, the driving device can be quickly and conveniently flipped to the lower side of the bridge and fixed through the suspension device, and then the image acquisition device is driven to move vertically and horizontally in combination with the driving device, so as to realize the automatic acquisition of the width distribution, length distribution, angle distribution and area distribution of the bottom surface cracks of the railway bridge, and effectively improve the detection efficiency and accuracy of the bridge surface cracks. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 The overall structure of a railway bridge surface crack automatic detection robot provided by an embodiment of the present application is shown;

[0028] Figure 2 A suspension device provided by an embodiment of the present application is shown;

[0029] Figure 3 A driving device and an image acquisition device provided in an embodiment of the present application are shown;

[0030] Figure 4 A rope fixing device provided in an embodiment of the present application is shown;

[0031] Figure 5 The diagram shows the deployment sequence of a suspension device provided in an embodiment of the present application.

[0032] Among them, 1, suspension device, 11, fixed rod, 12, sliding sleeve, 13, upper motor, 14, upper drive shaft, 15, pulley, 16, mechanical arm, 17, drive rope, 18, rope limit groove, 19, lower motor, 110, lower drive shaft, 111, mechanical arm rotation joint, 112, rope fixing device, 113, drive device support rod, 1121, limit plate, 1122, rotating ring, 1123, fixed shaft

[0033] 2. driving device, 21. longitudinal transmission motor, 22. longitudinal transmission mechanism, 23. transverse transmission motor, 24. transverse transmission mechanism, 25. first transmission shaft, 26. second transmission shaft;

[0034] 3. Image acquisition device, 31. Camera, 32. Camera fill light device, 33. Image acquisition device base;

[0035] 4. Bridge railings. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0037] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0038] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0040] like Figures 1 to 5As shown, the first aspect of this embodiment provides a railway bridge surface crack automatic detection robot, including a control device, an image acquisition device 3, an image post-processing system, a driving device 2 for driving the image acquisition device to move vertically and horizontally, and a suspension device 1 for driving the driving device to flip to the lower side of the bridge and hang it to the bridge railing; the image post-processing system is electrically connected to the image acquisition device to form an execution device, and the image post-processing system includes a hardware device capable of running the developed software. It also includes a power supply device, which includes a mobile power supply, and the power supply device is respectively connected to the control device, the suspension device, the driving device and the execution device. Specifically, the power supply device is connected to the control device; the power supply device is connected to the motor in the suspension device; the power supply device is connected to the motor in the driving device; the power supply device is connected to the camera in the execution device and the camera fill light device.

[0041] The control device is electrically connected to the image acquisition device, the drive device and the suspension device; specifically, the control device includes a suspension device control unit, a drive device control unit and an image acquisition device control unit; the suspension device control unit and the drive device control unit have programming capabilities. The suspension device control unit is connected to the upper and lower motors in the suspension device; the drive device control unit is connected to the motor in the drive device; the image acquisition device controller is connected to the camera in the execution device to control the camera shooting frequency, and the control device is placed in the safe area at both ends of the railway bridge.

[0042] The suspension device includes suspension components distributed on both sides, and the suspension components include a fixed rod 11, a mechanical arm 16 and a driving device support rod 113. The top of the mechanical arm is connected to the fixed rod, and the bottom is rotatably hinged with the driving device support rod through a mechanical arm rotation joint 111; an upper drive shaft 14 driven to rotate by an upper motor 13 is installed across the top of the two mechanical arms, and pulleys 15 are installed at both ends of the upper drive shaft, and a driving rope 17 is wound around the pulley. The mechanical arm is provided with a rope limiting groove 18, and the free end of the driving rope is connected to the driving device support rod on the corresponding side; a lower drive shaft 110 driven to rotate by a lower motor 19 is connected across the rotating joints of the mechanical arms on both sides. During implementation, the upper motor pulls the mechanical arm to rotate, and the lower motor drives the driving device support rod to rotate relative to the mechanical arm rotation joint, so that the driving device support rod can be expanded or retracted.

[0043] The driving device includes a longitudinal transmission mechanism 22 arranged on both sides and a transverse transmission mechanism 24 connected across the execution end of the longitudinal transmission mechanism, and the longitudinal transmission mechanism and the transverse transmission mechanism are respectively driven by a longitudinal transmission motor 21 and a transverse transmission motor 23. The two ends of the longitudinal transmission mechanisms on both sides are respectively connected across with a first transmission shaft 25 and a second transmission shaft 26.

[0044] The image acquisition device 3 comprises an image acquisition device base 33 installed at the execution end of the transverse transmission mechanism, and a camera 31 and a camera fill light device 32 installed on the image acquisition device base.

[0045] The driving device support rod is provided with a rope fixing device 112, and the free end of the driving rope is connected to the rope fixing device. The rope fixing device comprises a fixed shaft 1123 fixedly connected to the driving device support rod, a rotating ring 1122 rotatably sleeved with the fixed shaft, and a limit plate 1121 provided at the outer end of the fixed shaft, and the free end of the driving rope is connected to the rotating ring.

[0046] In the above embodiment, the folding and unfolding of the suspension device 1 is achieved by controlling the upper motor 13 and the lower motor 19; the upper motor 13 controls the rotation of the mechanical arm 16 by controlling the pulley 15 to pull and release the driving rope 17, and ensures that the driving rope 17 controls the rotation of the mechanical arm 16 at any angle through the rotating ring 1122 in the rope fixing device 112; the lower motor 19 controls the rotation of the driving device support rod 113 at any angle by controlling the mechanical arm rotation joint 111;

[0047] Please refer to Figure 5 , the unfolding process of the suspension device 1 provided in the embodiment of the present application, during the unfolding process of the suspension device 1, the upper motor 13 and the lower motor 19 need to cooperate to complete the entire process, specifically, from ① to ② is mainly achieved by the upper motor 13 controlling the pulley 15 to release the drive rope 17, from ② to ③ is mainly achieved by the lower motor controlling the mechanical arm rotation joint 111, and from ③ to ④ is mainly achieved by the upper motor 13 controlling the pulley 15 to pull the drive rope 17; the folding path of the suspension device 1 is opposite to the unfolding path of the suspension device 1, and during the folding process of the suspension device 1, the upper motor 13 and the lower motor 19 need to cooperate to complete the entire process, specifically, from ④ to ③ is mainly achieved by the upper motor 13 controlling the pulley 15 to release the drive rope 17, from ③ to ② is mainly achieved by the lower motor controlling the mechanical arm rotation joint 111, and from ② to ① is mainly achieved by the upper motor 13 controlling the pulley 15 to pull the drive rope 17.

[0048] In the above embodiment, the movement of the image acquisition device 3 is realized by the driving device 2. Specifically, the longitudinal transmission motor 21 controls the longitudinal transmission mechanism 22 to drive the image acquisition device 3 to move along the length direction of the bridge, and the transverse transmission motor 23 controls the transverse transmission mechanism 24 to drive the image acquisition device 3 to move in a direction perpendicular to the length direction of the bridge. Through the movement in the above two directions, the acquisition device can realize the scanning and shooting of the bottom surface of the bridge.

[0049] A second aspect of this embodiment provides a method for automatically detecting surface cracks of a railway bridge using the robot, comprising the following steps:

[0050] S1: deploy the driving device and the image acquisition device to the lower side of the railway bridge through the suspension device, and hang and fix the suspension device to the bridge railing;

[0051] S2: starting the driving device and the image acquisition device, and driving the image acquisition device to move vertically and horizontally through the driving device to automatically complete the scanning and shooting of the cracks on the bottom surface of the railway bridge;

[0052] S3: Start the image post-processing system, synthesize the panoramic image of the bottom surface of the railway bridge based on the image stitching algorithm, identify the cracks in the panoramic image based on the deep learning algorithm, and quantify the cracks on the bottom surface of the bridge based on the crack automatic quantification algorithm;

[0053] S4: Output a panoramic image of the cracks on the bottom surface of the railway bridge, output the width distribution, length distribution, angle distribution and area distribution of the cracks on the bottom surface of the railway bridge, and complete a railway bridge crack detection.

[0054] In the embodiment of the present application, the control device intelligently controls the suspension device, the driving device and the execution device to complete the automated, efficient and high-precision detection of detailed cracks on the bottom surface of the railway bridge, so as to achieve an accurate assessment of the safety and damage degree of the railway bridge in service.

[0055] In a possible implementation of the first aspect, the longitudinal transmission mechanism and the transverse transmission mechanism in the driving device may have two degrees of freedom or three degrees of freedom, and the three degrees of freedom can realize the change of the distance between the camera and the bottom surface of the bridge.

[0056] In a possible implementation of the first aspect, the fixing rod in the suspension device needs to be connected to the bridge railing 4. The connection can be by tying a number of plastic cable ties along the length direction of the fixing rod. The fixing rod and the bridge railing can form a whole in a short time, and can be quickly cut with scissors after completion. It can also be other fixing devices that can be quickly installed and disassembled.

[0057] In a possible implementation of the first aspect, the control device further includes a wireless signal expansion component, which is connected to the controller and is used to expand the wireless signal function of the controller.

[0058] The suspension device fully utilizes the guardrails on both sides of the railway bridge to achieve non-destructive anchoring of the inspection robot and the bridge.

[0059] If the inspection robot needs to be transferred to other areas after collecting pictures of the area where it is located, it only needs to cut the cable tie on the fixing rod, quickly move the inspection robot to the designated area using the railing as a track, and fix it with the cable tie without folding the suspension device.

[0060] The fixing rod is connected to the single-degree-of-freedom parallel robot arm through a sliding sleeve 12. Before detection, the sliding sleeve can slide according to the height of the railing and the size of the bridge, so that a single detection robot is suitable for more bridges.

[0061] The single-degree-of-freedom parallel robotic arm is connected in parallel through the upper and lower drive shafts of the two single-degree-of-freedom robotic arms, and the two single-degree-of-freedom robotic arms rotate synchronously through the drive shaft connection. Compared with a single robotic arm, the parallel robotic arm greatly increases the lateral stiffness and improves the wind resistance stability during the detection process.

[0062] The two-degree-of-freedom transmission mechanism in the driving device ensures that the camera can move freely in a plane parallel to the bottom surface of the bridge, avoiding the need for a high-degree-of-freedom robotic arm and reducing the difficulty of controlling the detection robot.

[0063] The two-degree-of-freedom transmission mechanism in the driving device can keep the camera moving parallel to the bottom surface of the bridge at a close distance. The close distance allows the collected pictures to have enough pixels, ensuring the identification of microcracks and accurate quantification of cracks. Keeping it parallel to the bottom surface of the bridge does not require additional sensors or calibration objects, and avoids time-consuming post-processing processes such as scaling parameters and correcting tilt deformation.

[0064] The control device is a programmable control device. The suspension control unit connected to the suspension device can automatically unfold and fold the suspension device by programming the rotation speed and angle of the single-degree-of-freedom parallel mechanical arm in the suspension device in advance. The drive control unit connected to the drive device can automatically capture images by programming the moving speed and path of the image acquisition device in advance. Since the mechanical arm rotates at a constant speed with a single degree of freedom and the camera moves at a constant speed along a single path, the running program of the detection robot is easy to program in advance, ensuring the automated detection of the detection robot.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A railway bridge surface crack automatic detection robot, characterized by: It includes a control device, an image acquisition device, a driving device for driving the image acquisition device to move vertically and horizontally, and a suspension device for driving the driving device to flip to the lower side of the bridge and hang it on the bridge railing; the control device is electrically connected to the image acquisition device, the driving device and the suspension device; The suspension device includes suspension components distributed on both sides, and the suspension components include a fixed rod, a mechanical arm and a driving device support rod. The top of the mechanical arm is connected to the fixed rod, and the bottom is rotatably hinged with the driving device support rod through a mechanical arm rotating joint; an upper driving shaft driven to rotate by an upper motor is installed across the tops of the two mechanical arms, and pulleys are installed at both ends of the upper driving shaft, and a driving rope is wound around the pulley, and the free end of the driving rope is connected to the driving device support rod on the corresponding side; a lower driving shaft driven to rotate by a lower motor is connected across the rotating joints of the mechanical arms on both sides.

2. The railway bridge surface crack automatic detection robot according to claim 1 is characterized by: The mechanical arm is provided with a rope limiting groove.

3. The railway bridge surface crack automatic detection robot according to claim 2 is characterized by: The driving device comprises a longitudinal transmission mechanism arranged on both sides and a transverse transmission mechanism connected across the execution end of the longitudinal transmission mechanism. The longitudinal transmission mechanism and the transverse transmission mechanism are driven by a longitudinal transmission motor and a transverse transmission motor respectively.

4. The railway bridge surface crack automatic detection robot according to claim 3 is characterized by: The two ends of the longitudinal transmission mechanisms on both sides are respectively cross-connected with a first transmission shaft and a second transmission shaft.

5. The railway bridge surface crack automatic detection robot according to claim 4 is characterized by: The image acquisition device comprises an image acquisition device base installed at the execution end of the transverse transmission mechanism, and a camera and a camera fill light device installed on the image acquisition device base.

6. The railway bridge surface crack automatic detection robot according to claim 5 is characterized by: A rope fixing device is arranged on the driving device support rod, and the free end of the driving rope is connected to the rope fixing device.

7. The railway bridge surface crack automatic detection robot according to claim 6 is characterized by: The rope fixing device comprises a fixed shaft fixedly connected to the driving device support rod, a rotating ring rotatably sleeved with the fixed shaft, and a limiting plate arranged at the outer end of the fixed shaft, and the free end of the driving rope is connected to the rotating ring.

8. The railway bridge surface crack automatic detection robot according to claim 7 is characterized by: It also includes an image post-processing system, which is electrically connected to the image acquisition device.

9. A method for automatically detecting surface cracks on a railway bridge using the robot as claimed in claim 8, characterized in that: The steps include: S1: deploy the driving device and the image acquisition device to the lower side of the railway bridge through the suspension device, and hang and fix the suspension device to the bridge railing; S2: starting the driving device and the image acquisition device, and driving the image acquisition device to move vertically and horizontally through the driving device to automatically complete the scanning and shooting of the cracks on the bottom surface of the railway bridge; S3: Start the image post-processing system, synthesize the panoramic image of the bottom surface of the railway bridge based on the image stitching algorithm, identify the cracks in the panoramic image based on the deep learning algorithm, and quantify the cracks on the bottom surface of the bridge based on the crack automatic quantification algorithm; S4: Output a panoramic image of the cracks on the bottom surface of the railway bridge, output the width distribution, length distribution, angle distribution and area distribution of the cracks on the bottom surface of the railway bridge, and complete a railway bridge crack detection.

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