Intelligent detection method and detection system for apparent cracks of tunnel lining

Abstract

The invention provides a tunnel lining apparent crack intelligent detection method and system, and relates to the technical field of crack detection.The tunnel lining apparent crack intelligent detection system comprises a tunnel body, a track assembly is arranged in the tunnel body and comprises a front end sliding rail and a rear end sliding rail, and the front end sliding rail and the rear end sliding rail are both of a semicircular structure; the track assembly is provided with a front-end slide rail and a rear-end slide rail, the outer edges of the front-end slide rail and the rear-end slide rail are spaced from the inner wall of the tunnel body, and detection assemblies are slidably mounted on the surfaces of the front-end slide rail and the rear-end slide rail. And the driving assembly drives the camera to perform semi-circumferential movement along the inner wall of the tunnel lining, comprehensive detection is performed on the surface of the tunnel lining between the two sliding rails, and the control device walks along the interior of the tunnel through alternate movement of the rail assembly, so that the whole tunnel is detected, and the detection efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of crack detection, and in particular to an intelligent detection method and system for apparent cracks in a tunnel lining. Background Art

[0002] Tunnel lining refers to a permanent structure that supports and maintains the long-term stability and durability of a tunnel. Its functions include: supporting and maintaining the stability of the tunnel; maintaining the space required for train operation; preventing weathering of the surrounding rock; and relieving the impact of groundwater. Therefore, tunnel linings must have sufficient strength, durability, and a certain degree of frost resistance, impermeability, and erosion resistance. Tunnel linings are mainly composed of arch rings, side walls, inverts, and bottom plates. Drains are also installed in the tunnel to drain water. However, during the construction process, due to factors such as location, climate, topography, and lining quality, uncontrollable changes in the regional medium (such as cavities, cracks, water seepage, etc.) often occur, resulting in tunnel lining quality defects that seriously affect traffic safety in the tunnel.

[0003] According to the inspection schemes of relevant standardization and certification and accreditation services, optical measurement is a common method, including laser scanning and photogrammetry. Photogrammetry takes pictures of the tunnel surface and uses image processing technology to extract crack information. These methods have the advantages of high precision and high efficiency. However, the limitation of the photogrammetry method is that the detection range is limited by the position of the lens, which is not convenient for comprehensive crack detection of the tunnel lining. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide an intelligent detection method and detection system for apparent cracks in tunnel linings to solve the problems raised in the above-mentioned background technology. The present invention has a novel structure. Through the installation and use of the track assembly and the detection assembly, the camera is arranged inside the tunnel lining, and the driving assembly drives the camera to move semi-circularly along the inner wall of the tunnel lining to perform a comprehensive inspection of the tunnel lining surface between the two slide rails. Through the alternating movement of the track assembly, the control device moves along the inside of the tunnel, thereby inspecting the entire tunnel and improving the inspection efficiency.

[0005] In order to achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions: an intelligent detection system for apparent cracks in a tunnel lining, comprising a tunnel body, a track assembly provided inside the tunnel body, the track assembly comprising a front slide rail and a rear slide rail, the front slide rail and the rear slide rail both being semicircular in structure, and the outer edges of the front slide rail and the rear slide rail being spaced a certain distance from the inner wall of the tunnel body, a detection assembly being slidably mounted on the surfaces of the front slide rail and the rear slide rail, the detection assembly comprising a bottom frame, the bottom frame being arranged at the bottom of the front slide rail and the rear slide rail, and the front slide rail and the rear slide rail are provided with a plurality of movable members. The bottoms of the two ends of the rail corresponding to the bottom frame are slidably connected with sliding frames, the sliding frame of the rear end slide rail is fixed on the bottom frame, a hollow groove is opened on the surface of the bottom frame, and the sliding frame of the front end slide rail is slidably installed inside the hollow groove, a camera is provided at the bottom of the bottom frame, and the camera moves along the bottom of the hollow groove, the front end slide rail and the rear end slide rail are located on both sides of the bottom frame and are slidably connected with slides, and a second friction plate is installed on the top of the slide through a rotating shaft, a driving assembly is provided on the surface of the rear end slide rail, and the driving assembly includes a pull rope, the pull rope is arranged along the track of the rear end slide rail, and the bottom frame is fixedly connected to the pull rope.

[0006] Furthermore, driving wheels are rotatably installed at the bottom of both sides of the front-end slide rail and the rear-end slide rail, and a driving motor is provided on the outside of the driving wheel. The driving motor is fixedly connected to the bottom of both sides of the front-end slide rail and the rear-end slide rail, and the output end of the driving motor is fixedly connected to the driving wheel, and auxiliary wheels are rotatably installed at equal intervals on the surface of the front-end slide rail and the rear-end slide rail.

[0007] Furthermore, both sides of the front end slide rail and the rear end slide rail are provided with a receiving groove, and an electric push rod is fixed inside the receiving groove, and a first friction plate is fixed to the extended end of the electric push rod.

[0008] Furthermore, the driving assembly also includes a winding seat, and a winding seat is fixed at the bottom of both sides of the rear end slide rail. The two ends of the pull rope are wound on the winding shaft of the winding seat, and limit blocks are fixed at equal distances on the surface of the rear end slide rail, and the pull rope slides through the limit blocks. A through groove is opened at the bottom of the limit block, and a fixed plate is fixed at the position of the bottom frame corresponding to the through groove, and the fixed plate is fixedly connected to the pull rope.

[0009] Furthermore, the detection component also includes a fixed frame, fixed frames are fixed on both sides of the sliding frame of the front-end slide rail, and a first motor is fixed on the outside of the fixed frame, a first gear is fixed to the output end of the first motor, and a tooth plate is meshed and connected to the top of the first gear, and the tooth plate is fixedly connected to the sliding frame of the rear-end slide rail.

[0010] Furthermore, bearing frames are fixed at both ends of the bottom of the bottom frame, and a screw is rotatably installed inside the bearing frame. A movable seat is threadedly sleeved on the surface of the screw, and the camera is fixedly installed on the top of the movable seat.

[0011] Furthermore, fixed columns are fixed on both sides of the middle of the bottom frame, and the outer ends of the fixed columns are fixed with a second motor, and the output end of the second motor is fixed with an insertion shaft.

[0012] Furthermore, two insertion rods are symmetrically inserted into the interior of the insertion shaft, the two insertion rods are staggered, and one end of the insertion rod is rotatably connected to the corresponding slide.

[0013] Furthermore, a contact block is fixed on one side of the slide close to the bottom frame, and the contact block is in compression contact with the side of the bottom frame, and a notch is provided on the top of the first friction plate for the auxiliary wheel to pass through.

[0014] A method for intelligently detecting apparent cracks in a tunnel lining, comprising the following steps: (1) Arrange the front and rear rails of the track assembly inside the track, and install the detection assembly on the two rails; (2) The camera is placed at one end through the hollow slot of the bottom frame to scan and detect the inner wall of the track between the two slide rails. The driving component drives the camera to move around the slide rail path. When a crack is detected, an image is collected. (3) The front slide rail and the rear slide rail move forward alternately, and the first motor drives the first gear to rotate and engage with the tooth plate. When the front slide rail is in the braking state, the rear slide rail drives the bottom frame to move forward. At the same time, the slide frame at the bottom of the front slide rail slides along the hollow groove. When the rear slide rail is in the braking state, the front slide rail can continue to move forward, completing the automatic movement of the device and performing crack detection on the entire tunnel; (4) The detected images are collected at the terminal, and a lightweight fully convolutional network is built based on the image features. The feature retention mechanism of interest and multi-level residual feature extraction are used in the process of network feature extraction and transmission to realize the extraction and recognition of subtle features of crack targets, and a recognition model is established. Based on the established recognition model, crack detection is performed on the tunnel lining image to be inspected to determine the crack location.

[0015] Beneficial effects of the present invention: The present invention drives the camera to move along the hollow groove by cooperating with the moving seat and the screw, and scans and detects the tunnel surface between the front slide rail and the rear slide rail. When a cracked or dirty area is identified, the camera automatically completes the photo collection.

[0016] The present invention controls the rotation of the driving wheel through a driving motor, thereby pushing the rear end slide rail or the front end slide rail to move, and maintains sliding contact with the inner wall of the track through the auxiliary wheel.

[0017] The present invention can keep the shape of the pull rope similar to the semicircular shape of the slide rail by passing the pull rope through the limit block, and then the bottom frame can slide along the surfaces of the rear end slide rail and the front end slide rail through the fixing plate.

[0018] The present invention drives the plug shaft to rotate by the second motor, and the two plug rods inserted in the plug shaft rotate with the second motor as the center of the circle, so that the slides on the front slide rail and the rear slide rail move up or down respectively, so that the first friction plate at the top alternately contacts the inner wall of the track body, and the electric push rods at the bottom of both sides of the front slide rail and the rear slide rail synchronously push the second friction plate out to contact the two sides of the inner wall of the track, thereby achieving a braking effect through friction force. Because the first friction plates on the front slide rail and the rear slide rail are both connected to the plug shaft, the locking of the front slide rail and the rear slide rail can be switched by the plug shaft, that is, when the rear slide rail contacts the inner wall of the tunnel through the first friction plate and the second friction plate, the front slide rail can continue to move forward and maintain stability through the rear slide rail. When the first friction plate and the second friction plate of the front slide rail contact the inner wall of the tunnel, the rear slide rail can be moved forward close to the front slide rail, and then the two sets of slide rails can be moved alternately in this way to achieve step-by-step movement of the device.

[0019] The first friction plate of the present invention is slidably sleeved on both sides of the front-end slide rail and the rear-end slide rail through the slide, and contacts with both sides of the bottom frame through the contact block, which can avoid the slide from colliding with the insertion shaft. At the same time, when the bottom frame moves with the driving assembly, it can also drive the two groups of slides and the first friction plate to move along the surface of the front-end slide rail and the rear-end slide rail, so as to maintain the connection between the insertion shaft and the insertion rod and the slide. The hollow on the first friction plate can allow the auxiliary wheel to pass through without movement interference.

[0020] Compared with the prior art, the present invention arranges the camera inside the tunnel lining through the installation and use of the track assembly and the detection assembly, and the driving assembly drives the camera to move semi-circularly along the inner wall of the tunnel lining, so as to perform a comprehensive inspection of the tunnel lining surface between the two slide rails. Through the alternating movement of the track assembly, the control device moves along the inside of the tunnel, thereby inspecting the entire tunnel and improving the inspection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic flow chart of an intelligent detection method for apparent cracks in tunnel linings according to the present invention; Figure 2 This is a schematic diagram of the overall structure of an intelligent detection system for apparent cracks in tunnel linings according to the present invention; Figure 3 This is a schematic diagram of the track assembly structure of an intelligent detection system for apparent cracks in tunnel linings according to the present invention; Figure 4 This is a schematic diagram of the upper structure of the bottom frame of an intelligent detection system for apparent cracks in a tunnel lining according to the present invention; Figure 5 This is a schematic diagram of the structure of a drive component of an intelligent detection system for apparent cracks in tunnel linings according to the present invention; Figure 6This is a schematic diagram of the side structure of a slide rail of an intelligent detection system for apparent cracks in a tunnel lining according to the present invention; Figure 7 This is a schematic diagram of the structure of a detection component of an intelligent detection system for apparent cracks in a tunnel lining according to the present invention; Figure 8 This is a schematic diagram of the connection between the second gear and the plug shaft of an intelligent detection system for apparent cracks in a tunnel lining according to the present invention; Figure 9 This is a schematic diagram of the bottom structure of the bottom frame of an intelligent detection system for apparent cracks in tunnel linings according to the present invention.

[0022] In the figure: 1. Tunnel body; 2. Track assembly; 21. Rear slide rail; 22. Front slide rail; 23. Driving wheel; 24. Driving motor; 25. Auxiliary wheel; 26. Storage slot; 27. Electric push rod; 28. First friction plate; 3. Detection assembly; 31. Bottom frame; 32. Hollow slot; 33. Slide frame; 34. Camera; 35. Bearing frame; 36. Screw; 37. Moving seat; 38. Fixed frame; 39. First motor; 310. First gear; 311. Tooth plate; 312. Slide; 313. Second friction plate; 314. Fixed column; 315. Second motor; 316. Insert shaft; 317. Contact block; 4. Driving assembly; 41. Pull rope; 42. Limit block; 43. Through slot; 44. Fixed plate; 45. Rewinding seat. DETAILED DESCRIPTION

[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0024] See also Figures 1 to 9 , the present invention provides a technical solution: A method for intelligently detecting apparent cracks in a tunnel lining, comprising the following steps: (1) Arrange the front and rear rails of the track assembly inside the track, and install the detection assembly on the two rails; (2) The camera is placed at one end through the hollow slot of the bottom frame to scan and detect the inner wall of the track between the two slide rails. The driving component drives the camera to move around the slide rail path. When a crack is detected, an image is collected. (3) The front slide rail and the rear slide rail move forward alternately, and the first motor drives the first gear to rotate and engage with the tooth plate. When the front slide rail is in the braking state, the rear slide rail drives the bottom frame to move forward. At the same time, the slide frame at the bottom of the front slide rail slides along the hollow groove. When the rear slide rail is in the braking state, the front slide rail can continue to move forward, completing the automatic movement of the device and performing crack detection on the entire tunnel; (4) The detected images are collected at the terminal, and a lightweight fully convolutional network is built based on the image features. The feature retention mechanism of interest and multi-level residual feature extraction are used in the process of network feature extraction and transmission to realize the extraction and recognition of subtle features of crack targets, and a recognition model is established. Based on the established recognition model, crack detection is performed on the tunnel lining image to be inspected to determine the crack location.

[0025] A tunnel lining surface crack intelligent detection system includes a tunnel body 1, wherein a track assembly 2 is provided inside the tunnel body 1, and the track assembly 2 includes a front slide rail 22 and a rear slide rail 21, wherein the front slide rail 22 and the rear slide rail 21 are both semicircular structures, and the outer edges of the front slide rail 22 and the rear slide rail 21 are at a certain distance from the inner wall of the tunnel body 1, and a detection assembly 3 is slidably installed on the surface of the front slide rail 22 and the rear slide rail 21, and the detection assembly 3 includes a bottom frame 31, wherein the bottom frame 31 is arranged at the bottom of the front slide rail 22 and the rear slide rail 21, and the bottoms of the front slide rail 22 and the rear slide rail 21 corresponding to the two ends of the bottom frame 31 are slidably sleeved with slide frames 33, and the slide frame 33 of the rear slide rail 21 is fixed on the bottom frame 31, and a hollow groove 32 is opened on the surface of the bottom frame 31, and the slide frame 33 of the front slide rail 22 is slidably installed in the hollow groove 32, and the bottom of the bottom frame 31 The front end of the track 22 and the rear end of the track 21 are respectively provided with a camera 34 and a camera 34. The camera 34 moves along the bottom of the hollow groove 32. The front end slide rail 22 and the rear end slide rail 21 are located on both sides of the bottom frame 31 and are slidably sleeved with a slide 312. The top of the slide 312 is rotatably installed with a second friction plate 313 through a rotating shaft. A driving component 4 is provided on the surface of the rear end slide rail 21. The driving component 4 includes a pull rope 41. The pull rope 41 is arranged along the track of the rear end slide rail 21, and the bottom frame 31 is fixedly connected to the pull rope 41. When the device is used, the front end slide rail 22 and the rear end slide rail 21 of the track assembly 2 are arranged inside the track. The detection component 3 is installed on the two slide rails. One end of the camera 34 is provided through the hollow groove 32 of the bottom frame 31 to scan and detect the inner wall of the track between the two slide rails. When a crack position is detected, an image is collected. After circling the tunnel, the two slide rails of the track assembly 2 move forward alternately to detect the next point.

[0026] In this embodiment, driving wheels 23 are rotatably installed at the bottom of both sides of the front end slide rail 22 and the rear end slide rail 21, and a driving motor 24 is provided on the outside of the driving wheel 23. The driving motor 24 is fixedly connected to the bottom of both sides of the front end slide rail 22 and the rear end slide rail 21, and the output end of the driving motor 24 is fixedly connected to the driving wheel 23. Auxiliary wheels 25 are equidistantly rotatably installed on the surface of the front end slide rail 22 and the rear end slide rail 21. The rotation of the driving wheel 23 is controlled by the driving motor 24, which can push the rear end slide rail 21 or the front end slide rail 22 to move, and the sliding contact with the inner wall of the track is maintained by the auxiliary wheel 25.

[0027] In this embodiment, the driving component 4 also includes a winding seat 45, and a winding seat 45 is fixed at the bottom of both sides of the rear end slide rail 21. The two ends of the pull rope 41 are wound on the winding shaft of the winding seat 45, and the limit blocks 42 are fixed at equal distances on the surface of the rear end slide rail 21, and the pull rope 41 slides through the limit blocks 42. A through groove 43 is opened at the bottom of the limit block 42, and a fixing plate 44 is fixed at the position of the bottom frame 31 corresponding to the through groove 43, and the fixing plate 44 is fixedly connected to the pull rope 41. The two winding seats 45 have separate motor controls, and one is for winding and the other is for unwinding. By passing the pull rope 41 through the limit block 42, the shape of the pull rope 41 can be kept similar to the semicircular shape of the slide rail, and then the bottom frame 31 can slide along the surface of the rear end slide rail 21 and the front end slide rail 22 through the fixed plate 44.

[0028] In this embodiment, the detection component 3 also includes a fixed frame 38, fixed frames 38 are fixed on both sides of the slide frame 33 of the front end slide rail 22, and a first motor 39 is fixed on the outside of the fixed frame 38, a first gear 310 is fixed to the output end of the first motor 39, and a tooth plate 311 is meshed and connected to the top of the first gear 310, and the tooth plate 311 is fixedly connected to the slide frame 33 of the rear end slide rail 21, and bearing frames 35 are fixed to the bottom ends of the bottom frame 31, and a screw 36 is rotatably installed inside the bearing frame 35, and a moving seat 37 is threadedly sleeved on the surface of the screw 36, and the camera 34 is fixedly installed on the top of the moving seat 37, and the screw 36 is driven by a small motor, and the moving seat 37 cooperates with the screw 36 to drive the camera 34 along the hollow The empty slot 32 moves to scan and detect the tunnel surface between the front slide rail 22 and the rear slide rail 21. When a cracked or dirty area is identified, photo collection is automatically completed. The movable seat 37 also includes a battery for powering the camera 34, as well as an acquisition module, a storage module and a wireless module. The collected image is sent to the data terminal for crack identification and size measurement. The first motor 39 drives the first gear 310 to rotate and engage with the tooth plate 311. When the front slide rail 22 is braked, the rear slide rail 21 drives the bottom frame 31 to move forward. At the same time, the slide frame 33 at the bottom of the front slide rail 22 slides along the hollow slot 32. When the rear slide rail 21 is braked, the front slide rail 22 can continue to move forward, completing the automatic movement of the device.

[0029] In this embodiment, both sides of the front end slide rail 22 and the rear end slide rail 21 are provided with a receiving groove 26, and an electric push rod 27 is fixed inside the receiving groove 26, and a first friction plate 28 is fixed to the extended end of the electric push rod 27, and a fixing column 314 is fixed on both sides of the middle of the bottom frame 31, and a second motor 315 is fixed to the outer end of the fixing column 314, and a plug shaft 316 is fixed to the output end of the second motor 315, and two plug rods are symmetrically inserted into the interior of the plug shaft 316, and the two plug rods are staggered, and one end of the plug rod is rotatably connected to the corresponding slide 312, and the slide 312 is close to the bottom frame 31. The first friction plate 28 is provided with a notch on the top of the first friction plate 28 for the auxiliary wheel 25 to pass through. The first friction plate 28 is slidably sleeved on both sides of the front slide rail 22 and the rear slide rail 21 through the slide 312, and contacts both sides of the bottom frame 31 through the contact block 317, which can prevent the slide 312 from colliding with the insertion shaft 316. At the same time, when the bottom frame 31 moves with the driving assembly 4, it can also drive the two sets of slides 312 and the first friction plate 28 to move along the surface of the front slide rail 22 and the rear slide rail 21, so as to keep the insertion shaft 316 and the insertion rod and the slide 312 The second motor 315 drives the plug shaft 316 to rotate, and the two plug rods plugged in the plug shaft 316 rotate with the second motor 315 as the center of the circle, so that the slide 312 on the front slide rail 22 and the rear slide rail 21 move up or down respectively, so that the first friction plate 28 at the top contacts the inner wall of the track body alternately, and the electric push rods 27 at the bottom of both sides of the front slide rail 22 and the rear slide rail 21 synchronously push the second friction plate 313 out to contact both sides of the inner wall of the track, and the friction force has a braking effect. 2 and the first friction plates 28 on the rear end slide rail 21 are connected to the plug shaft 316, and the plug shaft 316 can switch the locking of the front end slide rail 22 and the rear end slide rail 21, that is, when the rear end slide rail 21 contacts the inner wall of the tunnel through the first friction plate 28 and the second friction plate 313, the front end slide rail 22 can continue to move forward and maintain stability through the rear end slide rail 21. When the first friction plate 28 and the second friction plate 313 of the front end slide rail 22 contact the inner wall of the tunnel, the rear end slide rail 21 can be moved forward close to the front end slide rail 22, and then the device can be moved step by step by alternately moving the two sets of slide rails in this way.

[0030] When using the device, the front end slide rail 22 and the rear end slide rail 21 of the track assembly 2 are arranged inside the track, the detection assembly 3 is installed on the two slide rails, the screw 36 is driven by a small motor, and the moving seat 37 cooperates with the screw 36 to drive the camera 34 to move along the hollow groove 32, and scan and detect the tunnel surface between the front end slide rail 22 and the rear end slide rail 21. When a cracked or dirty area is identified, the photo collection is automatically completed. The mobile seat 37 also includes a battery for powering the camera 34, as well as an acquisition module, a storage module and a wireless module, and the collected image is sent to the data terminal for crack detection. Identification and size measurement, the first motor 39 drives the first gear 310 to rotate and engage with the tooth plate 311. When the front slide rail 22 is in the braking state, the rear slide rail 21 drives the bottom frame 31 to move forward. At the same time, the slide frame 33 at the bottom of the front slide rail 22 slides along the hollow groove 32. When the rear slide rail 21 is in the braking state, the front slide rail 22 can continue to move forward to complete the automatic movement of the device. The two winding seats 45 have separate motor control, and one is for winding and the other is for unwinding. The shape of the pull rope 41 can be kept similar to the semicircular shape of the slide rail by passing the pull rope 41 through the limit block 42, and then the bottom frame 31 is fixed The plate 44 can slide along the surface of the rear end slide rail 21 and the front end slide rail 22, and the second motor 315 drives the plug shaft 316 to rotate. The two plug rods plugged in the plug shaft 316 rotate with the second motor 315 as the center of the circle, so that the slide 312 on the front end slide rail 22 and the rear end slide rail 21 moves up or down respectively, so that the first friction plate 28 at the top alternately contacts the inner wall of the track body, and the electric push rods 27 at the bottom of both sides of the front end slide rail 22 and the rear end slide rail 21 synchronously push the second friction plate 313 out to contact both sides of the inner wall of the track, and the friction force has a braking effect. The first friction plates 28 on the rails 21 are connected to the plug shaft 316, and the plug shaft 316 can switch the locking of the front slide rail 22 and the rear slide rail 21, that is, when the rear slide rail 21 contacts the inner wall of the tunnel through the first friction plate 28 and the second friction plate 313, the front slide rail 22 can continue to move forward and maintain stability through the rear slide rail 21. When the first friction plate 28 and the second friction plate 313 of the front slide rail 22 contact the inner wall of the tunnel, the rear slide rail 21 can be moved forward close to the front slide rail 22, and then the two sets of slide rails can be moved alternately in this way to achieve step-by-step movement of the device.

[0031] The basic principles, main features and advantages of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention.

[0032] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An intelligent detection system for apparent cracks in a tunnel lining, comprising a tunnel body (1), characterized in that: A track assembly (2) is provided inside the tunnel body (1), and the track assembly (2) includes a front slide rail (22) and a rear slide rail (21). The front slide rail (22) and the rear slide rail (21) are both semicircular structures, and the outer edges of the front slide rail (22) and the rear slide rail (21) are spaced a certain distance from the inner wall of the tunnel body (1). A detection assembly (3) is slidably mounted on the surface of the front slide rail (22) and the rear slide rail (21). The detection assembly (3) includes a bottom frame (31), and the bottom frame (31) is arranged on the bottom of the front slide rail (22) and the rear slide rail (21). The bottoms of the front slide rail (22) and the rear slide rail (21) at both ends of the bottom frame (31) are slidably sleeved with sliding frames (33). The sliding frame (33) of the rear slide rail (21) The bottom frame (31) is fixed to the bottom frame (31), a hollow groove (32) is provided on the surface of the bottom frame (31), and the slide frame (33) of the front slide rail (22) is slidably installed inside the hollow groove (32), a camera (34) is provided at the bottom of the bottom frame (31), and the camera (34) moves along the bottom of the hollow groove (32), the front slide rail (22) and the rear slide rail (21) are located on both sides of the bottom frame (31) and are slidably sleeved with a slide (312), and a second friction plate (313) is rotatably installed on the top of the slide (312) through a rotating shaft, a driving component (4) is provided on the surface of the rear slide rail (21), and the driving component (4) includes a pull rope (41), the pull rope (41) is arranged along the track of the rear slide rail (21), and the bottom frame (31) is fixedly connected to the pull rope (41).

2. The intelligent detection system for apparent cracks in tunnel linings according to claim 1, characterized in that: Active wheels (23) are rotatably mounted on the bottoms of both sides of the front-end slide rail (22) and the rear-end slide rail (21), and a driving motor (24) is provided on the outside of the active wheel (23). The driving motor (24) is fixedly connected to the bottoms of both sides of the front-end slide rail (22) and the rear-end slide rail (21), and the output end of the driving motor (24) is fixedly connected to the active wheel (23). Auxiliary wheels (25) are rotatably mounted on the surfaces of the front-end slide rail (22) and the rear-end slide rail (21) at equal intervals.

3. The intelligent detection system for apparent cracks in tunnel linings according to claim 2, characterized in that: Both sides of the front slide rail (22) and the rear slide rail (21) are provided with a receiving groove (26), an electric push rod (27) is fixed inside the receiving groove (26), and a first friction plate (28) is fixed to the extended end of the electric push rod (27).

4. The intelligent detection system for apparent cracks in tunnel linings according to claim 1 is characterized by: The driving assembly (4) further includes a winding seat (45), and winding seats (45) are fixed to the bottom of both sides of the rear end slide rail (21), and both ends of the pull rope (41) are wound on the winding shaft of the winding seat (45), and limit blocks (42) are fixed at equal intervals on the surface of the rear end slide rail (21), and the pull rope (41) slides through the limit blocks (42), and a through groove (43) is provided at the bottom of the limit block (42), and a fixed plate (44) is fixed at a position of the bottom frame (31) corresponding to the through groove (43), and the fixed plate (44) is fixedly connected to the pull rope (41).

5. The intelligent detection system for apparent cracks in tunnel linings according to claim 3 is characterized by: The detection component (3) further includes a fixing frame (38), the fixing frames (38) being fixed on both sides of the slide frame (33) of the front slide rail (22), and a first motor (39) being fixed on the outside of the fixing frame (38), a first gear (310) being fixed to the output end of the first motor (39), a tooth plate (311) being meshed and connected to the top of the first gear (310), and the tooth plate (311) being fixedly connected to the slide frame (33) of the rear slide rail (21).

6. The intelligent detection system for apparent cracks in tunnel linings according to claim 5, characterized in that: Bearing frames (35) are fixed at both ends of the bottom of the bottom frame (31), and a screw (36) is rotatably installed inside the bearing frame (35). A movable seat (37) is threadedly sleeved on the surface of the screw (36), and the camera (34) is fixedly installed on the top of the movable seat (37).

7. The intelligent detection system for apparent cracks in tunnel linings according to claim 6, characterized in that: Fixed columns (314) are fixed on both sides of the middle of the bottom frame (31), and a second motor (315) is fixed to the outer ends of the fixed columns (314), and an insertion shaft (316) is fixed to the output end of the second motor (315).

8. The intelligent detection system for apparent cracks in tunnel linings according to claim 7, characterized in that: Two insertion rods are symmetrically inserted into the interior of the insertion shaft (316), the two insertion rods are staggered, and one end of the insertion rod is rotatably connected to the corresponding slide (312).

9. The intelligent detection system for apparent cracks in tunnel linings according to claim 8, characterized in that: A contact block (317) is fixed to one side of the slide (312) close to the bottom frame (31), and the contact block (317) is in extrusion contact with the side of the bottom frame (31). A notch is provided on the top of the first friction plate (28) for the auxiliary wheel (25) to pass through.

10. An intelligent detection method for apparent cracks in tunnel linings implemented by the system according to claim 1, characterized in that: The detection method comprises the following steps: (1) Arrange the front and rear rails of the track assembly inside the track, and install the detection assembly on the two rails; (2) The camera is placed at one end through the hollow slot of the bottom frame to scan and detect the inner wall of the track between the two slide rails. The driving component drives the camera to move around the slide rail path. When a crack is detected, an image is collected. (3) The front slide rail and the rear slide rail move forward alternately, and the first motor drives the first gear to rotate and engage with the tooth plate. When the front slide rail is in the braking state, the rear slide rail drives the bottom frame to move forward. At the same time, the slide frame at the bottom of the front slide rail slides along the hollow groove. When the rear slide rail is in the braking state, the front slide rail can continue to move forward, completing the automatic movement of the device and performing crack detection on the entire tunnel; (4) The detected images are collected at the terminal, and a lightweight fully convolutional network is built based on the image features. The feature retention mechanism of interest and multi-level residual feature extraction are used in the process of network feature extraction and transmission to achieve the extraction and recognition of subtle features of crack targets, establish a recognition model, and perform crack detection on the tunnel lining image to be inspected based on the established recognition model to determine the crack location.

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