Integrated vision acquisition module for tunnel apparent defects

Abstract

The present invention relates to an integrated vision acquisition module for tunnel apparent defects, mainly used for solving the problems in existing detection devices of low integration level, complex debugging, low acquisition accuracy, poor environmental adaptability and the like. The vision acquisition module consists of a mounting back plate, a housing, a machine vision system, an integrated control system, a heat dissipation mechanism, a protective mechanism, and a wire arrangement mechanism. The machine vision system is encapsulated inside the mounting back plate and the housing, the heat dissipation mechanism is mounted on the back of the mounting back plate, the protective mechanism functions among the mechanisms of the vision acquisition module, and the integrated control system and the wire arrangement mechanism are mounted in the center of the front of the mounting back plate. The vision acquisition module uses a modular design, can implement accurate digital imaging of tunnel full-sections, has an overall protection grade of IP65 and good heat dissipation performance while maintaining a high degree of modularity, is adapted to different tunnel profile sections, and can complete rapid and non-contact detection of apparent defects in tunnel lining such as cracks, water leakage, and exfoliation and defects in ancillary facilities such as signal mechanisms, optical cables, and communication cables.

Description

An integrated visual acquisition module for tunnel surface defects Technical Field

[0001] The present invention relates to a tunnel surface disease visual integrated acquisition module, which is applied to tunnel structure detection. Background Art

[0002] With the continuous development and improvement of my country's infrastructure, tunnels for highways, railways, and subways are experiencing a booming development trend, with a significant increase in both number and scale. With the commissioning of numerous tunnels, various factors, such as external loads, ground pressure, and concrete aging, have led to varying degrees of deformation, cracks, water seepage, and other defects. If these defects are not promptly detected and treated, they can endanger the operational safety of tunnel structures.

[0003] Tunnels are typical long-line projects, and the number of long and extra-long operating tunnels in China is constantly increasing. Traditional manual inspection tasks are heavy, inefficient, costly, subjective, and prone to large errors. They also have a significant impact on the normal operation of traffic and are difficult to meet the industry's inspection needs. Automated inspection equipment is urgently needed to improve tunnel inspection efficiency.

[0004] With the rapid development of technologies such as machine vision, laser scanning, and artificial intelligence, many technologies and methods for detecting tunnel surface defects have emerged. Patent CN114460090A discloses a tunnel lining surface defect detection system based on industrial cameras. It uses industrial cameras and deep learning algorithms as the main detection means, reducing manual labor intensity and human reading errors. Patent CN217385264U discloses a high-definition imaging detection device for railway tunnels. By setting up a specially structured device framework and rationally arranging imaging units, the integration level of the detection device is improved, and high-frequency industrial cameras and laser light sources are used to realize automated detection of cracks on the tunnel surface. Patent CN115326819A discloses a tunnel structure surface defect detection device. It obtains tunnel structure point cloud data through laser scanners and monitoring cameras, establishes a three-dimensional tunnel model and point cloud grayscale and depth image maps to identify and analyze the characteristics of tunnel surface defects. Most of the existing tunnel surface disease detection technologies and methods are unable to achieve full coverage of the tunnel section, and the image acquisition accuracy is low, making it difficult to meet the needs of tunnel crack detection, especially the requirement to detect durability cracks as wide as 0.1mm in subway tunnel structures. In addition, the non-fully enclosed design results in a low protection level for the mechanism and low adaptability to the working environment.

[0005] In summary, there is an urgent need for an integrated visual acquisition module for tunnel surface defects that supports full coverage of tunnel sections, high image acquisition accuracy, high protection level, and good environmental adaptability.

[0006] Summary of the Invention

[0007] The purpose of this invention is to design an integrated visual acquisition module for tunnel surface defects, mainly to solve the technical problems of low integration and modularization of existing detection equipment, complex visual system debugging, low acquisition accuracy, and poor environmental adaptability.

[0008] The objectives of the present invention can be achieved through the following technical solutions: an integrated visual acquisition module for tunnel surface defects, consisting of a mounting backplate and a shell, a machine vision system, an integrated control system, a heat dissipation mechanism, a protective mechanism and a wire management mechanism; the machine vision system is encapsulated inside the mounting backplate and the shell, the heat dissipation mechanism is installed on the back of the mounting backplate, the protective mechanism is placed between the various components that constitute the visual acquisition module, and the integrated control system and the wire management mechanism are installed in the center of the front of the mounting backplate.

[0009] The mounting back panel and the outer shell are polygonal structures with an overall beautiful design and a compact structure; on the front of the mounting back panel, multiple sets of camera / laser integrated component mounting positions, laser mounting positions, and laser driver circuit board mounting positions are provided on each side of the polygon; the central area of ​​the mounting back panel is provided with a core control mainboard mounting position, an optical fiber bracket, and a waterproof connector mounting position; two handles are provided on the back of the mounting back panel, and after the visual acquisition module is removed from a certain acquisition platform, it can be carried and transported by hand through the handles; mounting fasteners are provided around the central threading hole area for installation to the mounting bracket; square holes of corresponding sizes are reserved on the back of the mounting back panel for installing a heat dissipation device; a camera / laser window is installed on each side of the polygonal outer shell, and the window is adhered to the inner side of the outer shell with optical glass through a window pressure plate; a plurality of power / signal cable threading holes are provided in the central area of ​​the mounting back panel, and a plurality of cooling fan cable threading holes are distributed at the square holes of the heat dissipation device at the edge of the mounting back panel;

[0010] Furthermore, the mounting back plate of the visual acquisition module is installed and fixed with the mounting bracket using a slide installation method. A flexible shock-absorbing pad is provided on the contact surface between the mounting fastener of the visual acquisition module and the slide of the mounting bracket to ensure the shock absorption and stability of the visual acquisition module; a limit pin is provided in the slide to realize self-locking of the mounting fastener, ensuring that the visual acquisition module will not shake.

[0011] The machine vision system consists of an imaging system, a fill light system, and an adjustment mechanism. The imaging system consists of multiple high-resolution line array cameras and corresponding multiple camera lenses. After the line array cameras and camera lenses are assembled, they are installed in the camera mounting position of the camera / laser integrated assembly and rigidly connected by bolts. The fill light system consists of a laser and a laser lens. The laser is used for electrical / optical conversion and provides a laser light source. The laser lens shapes the laser point light source into a linear light source. The adjustment mechanism drives the laser lens to achieve rotation and deflection adjustment.

[0012] Furthermore, since the inspection object is a tunnel, the data collected by the machine vision system each time it images represents a cross-section of the tunnel. To ensure that the machine vision system can adapt to tunnels with different cross-sections, it needs to be installed at the center point of the tunnel cross-section. The corresponding equipment of the machine vision system is distributed around the center point of the visual acquisition module to ensure that each set of camera / laser integrated components adapts to the same amount of change when the tunnel contour changes.

[0013] Furthermore, multiple line array cameras are paired with corresponding large-area line scanning lenses, and the shooting ranges of adjacent cameras overlap, enabling full cross-section coverage of tunnels with various contours.

[0014] Furthermore, the laser light emitted by the laser is connected to the laser lens through an optical fiber. The cylindrical mirror inside the laser lens shapes the laser point light source into a linear light source, and the prism emits it at the corresponding fan angle, forming a linear uniform light band on the shooting surface. The light band range covers the camera's shooting area, providing high-intensity fill light for the camera shooting;

[0015] Furthermore, the adjustment mechanism is an adjusting worm + meshing tooth linkage mechanism. Rotating the adjusting worm drives the meshing teeth to move, thereby realizing stable step-by-step adjustment of the adjustment mechanism. The adjusting worm is engraved with scale marks, which can accurately control the adjustment step of the adjusting worm with an accuracy of up to 0.0428°; the adjustment mechanism is divided into two degrees of freedom adjustments: lens rotation adjustment and lens deflection adjustment. The lens rotation adjustment worm is located below the laser lens installation position, and there are four fixing bolts behind the lens. The bolts are tightened after the rotation adjustment is completed. The lens deflection adjustment worm is located above the laser lens installation position, and there is a fastening bolt on the front of the lens for fastening after the deflection adjustment is completed; the camera lens is fixed as a positioning reference. The fastening part and the adjustment part in the adjustment mechanism are separated and do not interfere with each other, which will not cause the adjustment mechanism to deflect when the bolts are tightened.

[0016] The integrated control system consists of a core control motherboard and multiple laser driver circuit boards. The core control motherboard can perform power distribution, signal distribution, laser trigger control, and imaging system signal acquisition control for the entire machine vision module; the laser driver circuit board performs trigger signal, power regulation, and temperature protection control for each laser.

[0017] Furthermore, to ensure high integration and low coupling of the visual acquisition module, the power input is a single-channel input. The external power cable of the visual acquisition module is connected to the core control motherboard. The core control motherboard stabilizes, regulates and distributes the input power, and outputs it to various devices in the imaging system, fill light system and heat dissipation mechanism respectively.

[0018] Furthermore, the core control motherboard integrates an encoder pulse distributor. Based on the pulse signal triggered by the encoder at a fixed distance, it builds a multi-channel timing synchronization and nanosecond pulse signal parallel excitation system with a high-precision time and frequency reference source, realizing high-speed synchronous imaging and transmission of the linear array camera array. Under high-speed dynamic detection conditions, the maximum misalignment of the tunnel longitudinal imaging is less than 1mm. Using the encoder pulse trigger method, the loading platform of the detection visual acquisition module collects fixed data when it moves forward, and no data is collected when it stops or moves backward.

[0019] Furthermore, the core control motherboard integrates a laser trigger signal distributor. The operation of the laser is controlled by the laser trigger signal distributor, which can accurately control the lighting time and lighting duration of the laser. When multiple laser driver circuit boards receive the laser trigger signal distributed by the core control motherboard, they control the corresponding lasers to perform electro-optical conversion and output laser light sources.

[0020] The heat dissipation mechanism consists of multiple sets of heat dissipation fins and corresponding external heat dissipation fans, which are symmetrically fixed to each side of the polygonal mounting backplate with bolts; when the bottom of the heat dissipation fins is installed, they pass directly through the reserved square holes to the interior of the visual acquisition module, and the air outlet surface of the heat dissipation fan faces the heat dissipation fins for cooling;

[0021] Furthermore, the main heat-generating component inside the visual acquisition module - the laser is directly fixed to the bottom of the heat sink fin, and thermal conductive adhesive is applied between its mounting surface and the mounting surface at the bottom of the heat sink fin. On the basis of ensuring the highly modular integrated packaging of the visual acquisition module, heat can be well conducted to the heat sink fin outside the visual acquisition module.

[0022] The protective mechanism mainly realizes the dustproof, waterproof and disassembly-proof of the visual acquisition module; the protective mechanism includes a dustproof and waterproof mechanism and an anti-disassembly mechanism, and the dustproof and waterproof mechanism is: a circle of waterproof tape is pasted at the connection between the outer shell of the visual acquisition module and the mounting backplate; when the heat sink fin is installed, a waterproof tape is padded between it and the mounting backplate; the optical glass edge of the camera / laser window is fixed and protected with waterproof glue; each wire threading hole of the mounting backplate is fixed with a waterproof connector base, and the corresponding cables are matched with waterproof aviation plugs. The cable connection can achieve IP67 level dustproof and waterproof, and the visual acquisition module as a whole achieves IP65 level dustproof and waterproof; the anti-disassembly mechanism consists of a rotating baffle, a spring and a pin shaft. The pin shaft is fixed to the mounting backplate, and the rotating baffle is moved to rotate around the pin shaft, thereby pressing the outer shell, so that non-professional technicians cannot remove the restriction on the rotating baffle, so that the outer shell cannot be removed even if the mounting bolts of the outer shell are removed, thereby achieving the anti-disassembly effect, protecting the internal safety of the visual acquisition module and realizing technical confidentiality.

[0023] The cable management mechanism is a ring-shaped optical fiber bracket installed in the central area of ​​the front of the back panel. The optical fiber bracket consists of two concentric rings with different diameters. A connecting rod is provided between the two rings at a certain angle. The optical fiber is fixed on the optical fiber bracket in a coiled manner.

[0024] Based on the tunnel structure surface images collected by the visual acquisition module, through image deep learning, sub-pixel edge segmentation, image geometric eigenvalue test correction and other methods, it is possible to achieve rapid, intelligent and digital detection of tunnel structure surface defects such as cracks, water leakage, spalling, pipe segment damage, and defects in ancillary facilities such as signal mechanisms, optical cables, and communication cables.

[0025] The beneficial effects of the present invention are:

[0026] (1) The present invention can realize digital imaging of the entire tunnel section and complete rapid, non-contact detection of surface defects such as tunnel lining cracks, water leakage, and spalling, as well as defects in auxiliary facilities such as signal mechanisms, optical cables, and communication cables;

[0027] (2) The present invention uses a linear array camera, equipped with a laser fill light, and is equipped with an adjustment mechanism in which the fastening part and the adjustment part do not interfere with each other, which can achieve stable step-by-step adjustment of the visual acquisition module, ensuring the continuity, integrity and clarity of image acquisition. The layout of the linear array camera takes into account a variety of tunnels and adapts to different tunnel profile sections;

[0028] (3) The present invention realizes a highly modular integrated packaging of the visual acquisition module. The visual acquisition module can be integrated into different detection platforms as a single detection unit. Users do not need to worry about the specific operation, assembly, and alignment of the internal imaging components. The anti-disassembly mechanism configured on the outer shell can effectively prevent non-professional technicians from disassembling it, further ensuring the internal security of the visual acquisition module and the confidentiality of the implementation technology.

[0029] (4) The overall protection level of the present invention is IP65. While being highly modularized and packaged, it also achieves good heat dissipation performance, is easy to disassemble, and has good environmental adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic diagram of the structural topology of the present invention;

[0031] FIG2 is a schematic diagram of the layout of the present invention;

[0032] FIG3 is a schematic diagram of the inner cavity structure of the present invention;

[0033] FIG4 is a schematic diagram of the back structure of the present invention;

[0034] FIG5 is a schematic diagram of the camera / laser integrated assembly of the present invention.

[0035] In the figure: 1-housing; 2-fiber optic bracket; 3-optical glass; 4-window pressure plate; 5-rotating baffle; 6-spring; 7-pin; 8-cooling fan; 9-cooling fins; 10-laser; 11-core control motherboard; 12-camera / laser integrated assembly; 13-laser driver circuit board; 14-mounting bracket; 15-network port connector; 16-handle; 17-flexible shock-absorbing pad; 18-mounting back plate; 19-waterproof connector; 20-waterproof breathable valve; 21-mounting fastener; 22-slide; 23-tightening bolt; 24-limit pin; 25-signal connector; 26-power connector; 27-laser lens; 28-camera lens; 29-camera / laser integrated assembly mounting base; 30-line array camera; 31-deflection adjustment mechanism; 32-laser fixing adjustment ring; 33-rotation adjustment mechanism. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below with reference to the accompanying drawings.

[0037] As shown in Figures 1 to 5, the layout of the visual acquisition module should consider symmetry and aesthetics. For example, quadrilateral and hexagonal layouts are symmetrical in both horizontal and vertical directions, which is aesthetically pleasing and helps ensure consistent image acquisition accuracy across all imaging systems. Taking a circular shield tunnel with an inner diameter of 5.5m as an example, the visual acquisition module is designed with a hexagonal symmetrical layout based on the designed acquisition accuracy. An integrated visual acquisition module for tunnel surface defects consists of a mounting backplate and housing, a machine vision system, an integrated control system, a heat dissipation mechanism, a protective mechanism, and a cable management mechanism. The machine vision system is encapsulated within the mounting backplate and housing, the heat dissipation mechanism is mounted on the back of the backplate, the protective mechanism is placed between the components of the visual acquisition module, and the integrated control system and cable management mechanism are mounted in the center of the front of the backplate.

[0038] The mounting back plate 18 and the outer shell 1 adopt a hexagonal symmetrical design, with an overall beautiful design and a compact structure; on the front of the mounting back plate 18, six groups of camera / laser integrated assembly 12 mounting positions, laser 10 mounting positions, and laser driver circuit board 13 mounting positions are symmetrically provided on each side of the hexagon; the central area of ​​the back plate is provided with a core control mainboard 11 mounting position, an optical fiber bracket 2 and a waterproof connector 19 mounting position; two handles 16 are designed on the back of the mounting back plate 18. After the visual acquisition module is removed from a platform, it can be carried and transported by the handles 16. Mounting fasteners 21 are provided around the central wire hole area for installation to the mounting bracket 14; a square hole of corresponding size is reserved on the back of the laser 10 mounting position for installation of the heat dissipation fins 9; a camera / laser window is installed on each side of the hexagonal outer shell 1, and the window is adhered to the inner side of the outer shell 1 with optical glass 3 through the window pressure plate 4; 9 power / signal cable threading holes are provided in the central area of ​​the mounting back plate 18, and 6 cooling fan 8 cable threading holes are symmetrically provided at the heat dissipation fins 9 on the edge of the mounting back plate 18.

[0039] Furthermore, the visual acquisition module is installed and fixed to the mounting bracket 14 through the mounting back plate 18 through the slide groove 22. The mounting back plate 18 is provided with a waterproof breathable valve 20. The mounting fastener 21 of the visual acquisition module and the contact surface of the slide groove 22 of the mounting bracket 14 are arranged with a flexible shock-absorbing pad 17 to ensure the shock absorption stability of the visual acquisition module; the mounting fastener 21 of the visual acquisition module is slid into the slide groove 22 of the mounting bracket 14. After reaching the specified position, the limit pin 24 in the slide groove 22 will automatically lock the mounting fastener 21 to prevent it from sliding out, and then by tightening the tightening bolt 23, it can be ensured that the visual acquisition module will not shake.

[0040] The machine vision system consists of an imaging system, a fill light system, and an adjustment mechanism; the imaging system consists of 6 high-resolution line array cameras 30 and corresponding 6 camera lenses 28. After the line array cameras 30 and the camera lenses 28 are assembled, they are installed on the camera mounting position on the camera / laser integrated component mounting seat 29 and are rigidly connected by bolts; the fill light system consists of a laser 10 and a laser lens 27. The laser 10 is used to perform electrical / optical conversion and provide a laser light source. The laser lens 27 shapes and outputs the laser light source provided by the laser 10; the laser lens 27 is fixed on the laser fixing adjustment ring 32 and is installed on the adjustment mechanism as a whole with the laser fixing adjustment ring 32. The adjustment mechanism drives the laser lens 27 to achieve rotation and deflection adjustment.

[0041] Furthermore, the visual acquisition module is first installed on the center line of the tunnel track, and the visual acquisition module is adjusted to the height of the tunnel center point through the height adjustment device of the mounting bracket 14 to ensure that the center point of the visual acquisition module is located at the center point of the tunnel; each camera / laser integrated component 12 of the machine vision system is installed symmetrically around the center point of the visual acquisition module. When the track contour changes, each group of camera / laser integrated components 12 adapts to the same amount of change, and the accuracy of the acquired image remains consistent.

[0042] Furthermore, the six line array cameras 30 are equipped with corresponding large-target line scanning lenses, and the overlapping shooting ranges of adjacent cameras are 130mm-230mm, which can achieve full cross-section coverage of tunnels with various contours; the line array cameras 30 are equipped with a line laser light source 7 to meet the detection speed of 20km / h, and the image acquisition accuracy can be better than 0.25mm / Pixel.

[0043] Furthermore, the laser emitted by the laser 10 is connected to the laser lens 27 through an optical fiber. The cylindrical mirror inside the laser lens 27 shapes the laser point light source into a line light source, and the laser is emitted at a fixed fan angle by the prism, forming a linear uniform light band with a width not exceeding 20 mm on the shooting surface. The light band range covers the shooting area of ​​the camera, providing high-intensity fill light for the shooting of the line array camera 30.

[0044] Furthermore, the adjustment mechanism is an adjustment worm + meshing tooth linkage mechanism. Rotating the adjustment worm drives the meshing teeth to move, thereby realizing stable step-by-step adjustment of the adjustment mechanism. The adjustment worm is engraved with scale marks, which can accurately control the adjustment step of the adjustment worm with an accuracy of up to 0.0428°; the adjustment mechanism is divided into two degrees of freedom adjustments: lens rotation adjustment and lens deflection adjustment. The lens rotation adjustment mechanism 33 is located below the installation position of the laser lens 27. There are 4 fixing bolts behind the lens. The bolts are tightened after the rotation adjustment is completed. The lens deflection adjustment mechanism 31 is located above the installation position of the laser lens 27. There is a fixing bolt on the front of the lens for tightening after the deflection adjustment is completed; the camera lens 28 is fixed and serves as a positioning reference. The fastening part and the adjustment part in the adjustment mechanism are separated and do not interfere with each other, which will not cause the adjustment mechanism to deflect when the bolts are tightened.

[0045] The integrated control system consists of a core control motherboard 11 and six laser driver circuit boards 13. The core control motherboard 11 is located in the central area of ​​the mounting backplane 18 and can perform power distribution, signal distribution, laser 10 trigger control, and imaging system signal acquisition control for the entire machine vision module; the laser driver circuit boards 13 are located on each side of the hexagonal mounting backplane 18 and perform trigger signal, power adjustment, and temperature protection control for each laser 10 respectively.

[0046] Furthermore, to ensure the high integration and low coupling of the visual acquisition module, the power supply line is a single input, and the external power cable of the visual acquisition module is connected to the core control motherboard 11. After the core control motherboard 11 stabilizes, adjusts and distributes the input power, the power output line is 18 channels, which are respectively output to 6 linear array cameras 30, 6 laser drive circuit boards 13 and 6 cooling fans 8.

[0047] Furthermore, the core control motherboard 11 integrates a coded pulse distributor. Based on the pulse signal triggered by the encoder at a fixed distance, a multi-channel timing synchronization and nanosecond pulse signal parallel excitation system of a high-precision time and frequency reference source is constructed to achieve high-speed synchronous imaging and transmission of 30 arrays of linear array cameras. At a speed of 20km / h, the maximum misalignment of the tunnel longitudinal imaging is less than 1mm; using the encoder pulse triggering method, fixed data is collected when the loading platform of the detection visual acquisition module moves forward, and no data is collected when it stops or moves backward.

[0048] Furthermore, the core control motherboard 11 integrates a laser trigger signal distributor. The operation of the laser 10 is controlled by the laser trigger signal distributor, which can accurately control the lighting time and lighting duration of the laser 10. When the six laser driving circuit boards 13 receive the laser trigger signal distributed by the core control motherboard 11, they control the corresponding lasers 10 to perform electro-optical conversion and output laser light sources.

[0049] The heat dissipation mechanism consists of 6 groups of heat dissipation fins 9 and corresponding external heat dissipation fans 8, which are symmetrically fixed to each side of the hexagonal mounting back plate 18 with bolts; the bottom of the heat dissipation fins 9 directly penetrates into the interior of the visual acquisition module through the reserved square holes of the mounting back plate 18, and the air outlet surface of the heat dissipation fan 8 faces the heat dissipation fins 9, and the heat dissipation fins 9 are cooled by the principle of air cooling.

[0050] Furthermore, the main heat-generating component inside the visual acquisition module—the laser 10—is directly fixed to the bottom of the heat sink fin 9, and thermal conductive glue is coated between its mounting surface and the mounting surface at the bottom of the heat sink fin 9. Heat can be well transferred to the heat sink fin 9 outside the visual module and further cooled by the cooling fan 8.

[0051] The protective mechanism realizes the dustproof, waterproof and disassembly-proof of the visual acquisition module; the protective mechanism includes a dustproof and waterproof mechanism and an anti-disassembly mechanism, and the dustproof and waterproof mechanism is: the outer shell 1 of the visual acquisition module and the mounting back plate 18 are sealed and connected with a waterproof tape; when the heat dissipation fins 9 are installed, a waterproof tape is padded between the mounting back plate 18; the edge of the optical glass 3 of the camera / laser window is glued with waterproof glue to fix it while protecting the window; each wire threading hole of the mounting back plate 18 is fixed with a waterproof connector 19 base, and the corresponding cables are equipped with waterproof plugs. The cable connection can achieve IP67 level dustproof and waterproof, and the visual acquisition module as a whole can achieve IP65 level dustproof and waterproof.

[0052] Furthermore, the anti-dismantling mechanism is composed of a rotating baffle 5, a spring 6 and a pin 7, which is fixed to the mounting back plate 18 by the pin 7. After the anti-dismantling device is installed, in a natural state, the spring 6 is used to ensure that the rotating baffle 5 does not affect the installation of other components. When the installation of other components is completed, the anti-dismantling setting is completed by toggling the rotating baffle 5 to rotate around the pin 7 and restricting it, thereby pressing the housing 1. Only when the technician releases the anti-dismantling setting, the spring 6 stores energy to restore the natural state and the disassembly is completed.

[0053] The cable management mechanism is an annular optical fiber bracket 2 installed in the central area of ​​the front of the back plate 18. The cable is fixed on the optical fiber bracket 2 in a coiled manner. Six connecting brackets are symmetrically provided between the two concentric rings of the optical fiber bracket 2. The optical fiber is coiled into a ring shape and placed on the optical fiber bracket 2. It is fixed with a cable tie at each connecting bracket, fixed in six places in a circumferential direction, and is connected to the corresponding components in six ways when it reaches the designated outlet position.

[0054] In actual use, the visual acquisition module uses a non-contact method to detect tunnel surface defects. Specifically:

[0055] (1) Power is input to the vision acquisition module through the power connector 26, and after being distributed by the core control motherboard 11, it powers all devices inside the machine vision module, and all devices enter the power-on working state;

[0056] (2) The main control system sends a start operation instruction to the image acquisition system through the network port connector 15 and the signal connector 25, and at the same time inputs the laser trigger pulse signal into the visual acquisition module, which is then input into the six laser drive circuit boards 13 through the laser trigger pulse signal distributor. After receiving the signal, the laser drive circuit board 13 controls the laser 10 to output laser light, which enters the laser lens 27 through the optical fiber and is shaped to form a linear light band, providing a fill light source for the shooting area of ​​the linear array camera 30;

[0057] (3) After receiving the start operation instruction, the image acquisition system controls the six linear array cameras 30 to enter the image acquisition state. The linear array cameras 30 need to receive the trigger signal again before they can acquire images according to the signal;

[0058] (4) The pulse signal of the encoder is input to the visual acquisition module, and the pulse signal is input to the six linear array cameras 30 through the encoding pulse distributor. The linear array cameras 30 start to acquire images after receiving the pulse signal.

[0059] Based on the surface images of the tunnel structure collected by the module, through methods such as image deep learning, sub-pixel edge segmentation, and image geometric eigenvalue test correction, it is possible to achieve rapid, non-contact detection of apparent defects such as tunnel lining cracks, water leakage, and peeling, as well as defects in ancillary facilities such as signal mechanisms, optical cables, and communication cables. Users can judge the status of the tunnel based on the analysis results and use this as a basis to guide tunnel maintenance.

[0060] The above describes preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection claimed by the claims of the present invention.

Claims

1. An integrated visual acquisition module for tunnel surface defects, characterized by: It includes a mounting backplate and a housing, a machine vision system, an integrated control system, a heat dissipation mechanism, a protective mechanism, and a cable management mechanism; the machine vision system is encapsulated inside the mounting backplate and the housing, the heat dissipation mechanism is installed on the back of the mounting backplate, the protective mechanism is placed between the components of the vision acquisition module, and the integrated control system and the cable management mechanism are installed at the center of the front of the mounting backplate; The mounting back plate and the housing are polygonal structures; on the front of the mounting back plate, each side of the polygonal mounting back plate is provided with a group of camera / laser integrated component mounting positions, laser mounting positions, and laser driver circuit board mounting positions; the front center area of the mounting back plate is provided with a core control mainboard mounting position, an optical fiber bracket, and a waterproof connector mounting position; a camera / laser window is installed on each side of the polygonal housing, and the camera / laser window is adhered to the inner side of the housing with optical glass through a window pressure plate; the central area of the mounting back plate is provided with a plurality of power / signal cable threading holes, and the square hole of the heat dissipation device at the edge of the mounting back plate is provided with a plurality of fan cable threading holes; The machine vision system includes an imaging system, a fill light system, and an adjustment mechanism; the imaging system is composed of at least one line array camera and a matching camera lens, the line array camera being mounted on the camera mounting position of the camera / laser integrated assembly and rigidly connected with bolts; the fill light system includes a laser and a laser lens, the laser being used to perform electrical / optical conversion and provide a laser light source, the laser lens being fixed to a laser fixing adjustment ring, the laser lens performing linear conversion on the laser light source provided by the laser, and outputting the point light source as a linear light band; the adjustment mechanism acts on the laser lens, driving the laser lens to achieve rotation and deflection adjustment; The integrated control system includes a core control motherboard and multiple laser driver circuit boards. The core control motherboard can distribute power, distribute signals, control laser triggering, and control imaging system signal acquisition for the entire machine vision module. The laser driver circuit boards control trigger signals, power regulation, and temperature protection for each laser. The entire visual acquisition module is powered by a single external power cord. The heat dissipation mechanism includes multiple sets of heat dissipation fins and corresponding external heat dissipation fans, which are fixed to each side of the mounting back plate with bolts; the bottom of the heat dissipation fins passes through the square holes reserved in the mounting back plate. Passing through the interior of the visual acquisition module, the air outlet surface of the cooling fan faces the cooling fins; The protective mechanism includes a dustproof and waterproof mechanism and an anti-disassembly mechanism. The dustproof and waterproof mechanism is as follows: a circle of waterproof tape is pasted at the connection between the housing of the visual acquisition module and the mounting backplate; a waterproof tape is padded between the heat dissipation fins and the mounting backplate; the optical glass edge of the camera / laser window is fixed and protected with waterproof adhesive; each threading hole of the mounting backplate is fixed with a waterproof connector base, and the cable is connected to a waterproof plug. The anti-disassembly mechanism includes a rotating baffle, a spring and a pin shaft. The pin shaft is fixed to the mounting backplate, and the rotating baffle is moved to rotate around the pin shaft and press the housing tightly. The cable management mechanism is an annular optical fiber bracket in the front center area of the mounting backplane, and the annular optical fiber bracket is composed of two concentric rings with different diameters. A connecting rod is provided between the two rings at a certain angle. The optical fiber is fixed on the optical fiber bracket in a coiled manner, and the cable is fixed on the optical fiber bracket in a coiled manner and is connected to the corresponding equipment when it reaches the designated outlet position.

2. The integrated visual acquisition module for tunnel surface defects according to claim 1 is characterized in that: A square hole of corresponding size is reserved on the back of the mounting back plate for installing the heat dissipation device; two handles are provided on the back of the mounting back plate, and mounting fasteners are designed around the central threading hole area of the mounting back plate for mounting to the mounting bracket.

3. The integrated visual acquisition module for tunnel surface defects according to claim 1 is characterized in that: The visual acquisition module is installed and fixed by a slide groove, and the contact surface between the mounting fastener of the visual acquisition module and the slide groove of the mounting bracket is provided with a flexible shock-absorbing pad.

4. The integrated visual acquisition module for tunnel surface defects according to claim 1 is characterized in that: The laser lens and the adjusting mechanism for fixing the laser lens, the linear array camera, and the camera lens are installed on the back panel mounting position as the camera / laser integrated assembly.

5. The integrated visual acquisition module for tunnel surface defects according to claim 1 is characterized in that: The installation position of the visual acquisition module is the center point of the tunnel section. The camera / laser integrated assembly, the laser, the camera / laser window, and the heat dissipation mechanism are distributedly installed around the center point of the visual acquisition module, and the various components are distributed in a circular manner around the concentric point of the visual acquisition module.

6. The integrated visual acquisition module for tunnel surface defects according to claim 1 is characterized in that: The adjustment mechanism is a linkage mechanism, including an adjusting worm and meshing teeth. The rotation of the adjusting worm can drive the meshing teeth to move, thereby realizing stable step-by-step adjustment of the adjustment mechanism. The adjusting worm is engraved with scale marks. The adjustment mechanism for lens rotation is located below the laser lens and is fixed after adjustment through multiple fixing bolts on the back; the adjustment mechanism for lens deflection is located above the laser lens and is fixed after adjustment through a fixing bolt on the front; the camera lens is fixed, and the fastening part and the adjustment part in the adjustment mechanism are separated.

7. The integrated visual acquisition module for tunnel surface defects according to claim 1 is characterized in that: The laser light emitted by the laser is connected to the laser lens through an optical fiber. The inner cylindrical mirror of the laser lens shapes the laser point light source into a linear light source, and the prism emits it at a certain fan angle to form a linear uniform light band on the shooting surface.

8. The integrated visual acquisition module for tunnel surface defects according to claim 1 is characterized in that: The encoding pulse distributor is integrated into the core control motherboard, which can realize high-speed synchronous imaging and transmission of the linear array camera array; the encoder pulse triggering method is used to detect that when the loading platform of the visual acquisition module moves forward, fixed data is collected; when it stops or moves backward, no data is collected.

9. The integrated visual acquisition module for tunnel surface defects according to claim 1 is characterized in that: The laser trigger signal distributor is integrated into the core control motherboard. The operation of the laser is controlled by the laser trigger signal distributor, which can accurately control the lighting time and lighting duration of the laser. When the laser driver circuit board receives the laser trigger signal distributed by the core control motherboard, it controls the corresponding laser to perform electro-optical conversion and output a laser light source.

10. The integrated visual acquisition module for tunnel surface defects according to claim 1 is characterized in that: The laser is directly fixed on the bottom of the heat sink fin, and heat conductive glue is coated between the mounting surface of the laser and the bottom mounting surface of the heat sink fin.

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