Road tunnel inspection system and method based on unmanned aerial vehicle

Abstract

The invention discloses a highway tunnel inspection system and method based on an unmanned aerial vehicle, and relates to the field of highway tunnel inspection, an unmanned aerial vehicle module, a monitoring module and a protection module, the monitoring module is arranged on the unmanned aerial vehicle module, and the monitoring module is used for obtaining images and data in a tunnel; the protection module comprises a protection frame, the protection frame comprises a plurality of polygonal frames, the protection frame is a polyhedral frame formed by connecting the vertexes of the polygonal frames, the unmanned aerial vehicle module and the monitoring module are located in the protection frame, and each polygonal frame is provided with a plurality of anti-collision air bags. According to the system, the unmanned aerial vehicle module and the monitoring module are wrapped in the polyhedral frame, through the polyhedral frame and the rolling anti-collision air bag on the polyhedral frame, the anti-collision performance and the flight safety performance of the unmanned aerial vehicle are effectively improved, the system can roll and fly close to the tunnel wall, and the influence of vehicle wind pressure on the flight stability of the unmanned aerial vehicle is prevented.

Description

Technical Field

[0001] The present invention relates to the field of highway tunnels, and in particular to a highway tunnel inspection system and method based on an unmanned aerial vehicle (UAV). Background Art

[0002] With the continuous development of transportation infrastructure, highway tunnels, as a vital component of the transportation network, are crucial for their safe and stable operation. Traditional highway tunnel inspection methods have numerous limitations. For example, manual tunnel inspections involve inspectors carrying detection equipment (such as crack detectors and convergence meters) into the tunnel and determining defects based on visual inspection and experience. However, this method requires personnel to enter a closed, humid, and toxic environment, making them susceptible to collapses or traffic accidents. Furthermore, efficiency and accuracy are low, with missed detection rates exceeding 30%, and the inspection is significantly affected by factors such as fatigue and lighting. Furthermore, a single inspection can take several hours and cannot cover the entire length of a long tunnel. Furthermore, data management is backward, relying on paper records, resulting in fragmented and difficult-to-trace information.

[0003] Existing methods also use fixed automated monitoring equipment to deploy sensors (strain gauges, displacement gauges) and cameras to achieve fixed-point monitoring. However, this method can only monitor the installation points and cannot fully detect the overall condition of the tunnel (such as side wall cracks and vault spalling).

[0004] Other approaches utilize intelligent inspection robots for monitoring. These track-mounted robots move along pre-set tracks and are equipped with high-definition cameras and infrared sensors. However, this method requires pre-installed tracks, making retrofitting difficult and inflexible. Furthermore, laying tracks within tunnels can easily cause cracks, which can damage the integrity of the lining, leading to stress concentration, accelerated concrete carbonization, and steel corrosion, weakening the structure's bearing capacity. In eccentrically loaded, soft rock formations (such as mudstone tunnels), cracks can easily lead to local collapse or large deformation. Longitudinal cracks in the vault, in particular, can induce continuous fractures.

[0005] With the continuous advancement of science and technology, drone technology has gradually matured and is being widely used in various fields. Drones can quickly reach various locations in tunnels, eliminating the terrain and traffic restrictions that manual inspections face. By pre-setting flight routes, drones can complete comprehensive tunnel inspections in a short period of time, greatly improving inspection efficiency.

[0006] The drones are equipped with advanced inspection equipment, including high-definition cameras, infrared sensors, and lidar, enabling comprehensive, high-precision inspections of tunnel structures and facilities. These devices can detect subtle cracks and deformations on the tunnel surface, as well as the operational status of internal facilities. During their inspections, the drones transmit the collected data to the ground control center in real time. Using professional data analysis software, personnel can quickly process and analyze this data, promptly identifying tunnel problems and developing appropriate solutions. This provides strong support for the timely detection and resolution of safety hazards.

[0007] However, during inspections, drones (especially multi-rotor drones) rely on aerodynamic balance to maintain their posture. Directional wind pressure generated by vehicles in highway tunnels, such as strong winds along the tunnel's direction, can disrupt the drone's force balance, causing it to deviate from its intended route. Wind pressure can push it toward the tunnel wall or the direction of the vehicle. Unstable airflow caused by eddies, such as sudden sideways winds, can cause the drone's posture to oscillate, with sudden changes in roll and pitch angles, posing a risk of collision and potentially damaging the equipment. Summary of the Invention

[0008] One object of the present invention is to provide a highway tunnel inspection system and method based on a drone. The drone module and the monitoring module are wrapped in a protection module, and the anti-collision airbag on the protection module rolls and flies close to the tunnel wall, which can initially prevent the vehicle wind pressure from affecting the flight stability of the drone; even if the drone module collides under the influence of large wind pressure, the airbag of the anti-collision airbag acts on the impact point and cushions the impact force through the rotation of the anti-collision airbag, which can effectively avoid damage to the drone module.

[0009] This purpose is achieved by adopting the following technical solutions:

[0010] The drone-based highway tunnel inspection system includes a drone module, a monitoring module and a protection module. The monitoring module is set on the drone module. The monitoring module includes a camera, which is used to obtain images inside the tunnel and identify abnormalities such as cracks, water seepage, exposed steel bars, etc. based on the captured images.

[0011] The protection module includes a protection frame, which includes several polygonal frames. The protection frame is a polyhedron frame with vertices of the polygonal frames connected to each other. The drone module and the monitoring module are located in the protection frame, and the polygonal frames are each provided with several anti-collision airbags.

[0012] During use, the drone module and monitoring module are located within the protective frame. The monitoring module's camera captures images through the area enclosed by the protective frame's polygonal frame. The drone module drives the protective and monitoring modules together within the tunnel, collecting tunnel data while moving to monitor the tunnel. When a vehicle enters a tunnel at high speed, the piston effect creates sudden lateral airflow, causing the drone module to roll, pitch, or yaw. Furthermore, the tunnel's narrow space can cause airflow to rebound from the sidewalls, further amplifying attitude disturbances and causing the drone module to collide multiple times within the tunnel.

[0013] On this basis, this system sets up a protective frame on the drone module, which wraps the drone module and the monitoring module in a polyhedron frame. Each polygonal frame of the polyhedron frame will not affect the monitoring module's data collection of the tunnel. At the same time, when the drone module collides in the tunnel, the protective frame of this system first contacts the wall of the tunnel, and several anti-collision airbags on each polygonal frame contact the impact point. The anti-collision airbags absorb the impact kinetic energy through elastic deformation, reducing the direct collision force of the drone module and the monitoring module, thereby avoiding damage to the drone module and the monitoring module.

[0014] Existing drone inspection systems rely on drones flying directly through tunnels. These drones are susceptible to collision damage due to wind pressure, resulting in high maintenance costs and poor long-term use. This system achieves this by encasing the drone and monitoring modules within a polyhedron frame and providing collision-resistant airbags to cushion the impact.

[0015] Preferably, each side of the polygonal frame is provided with a plurality of anti-collision airbags, and the distance between two adjacent anti-collision airbags on each side is the same. When collisions occur at different angles, the anti-collision airbags on different sides of the polygonal frame act on the wall, further improving the cushioning effect.

[0016] Furthermore, the anti-collision airbag can rotate circumferentially within the polygonal frame. The anti-collision airbag is in the shape of a roller. When the anti-collision airbag contacts the collision site, the anti-collision airbag rolls, further cushioning the collision through sliding and improving the anti-collision effect.

[0017] The system also includes a path module, which is used to move the drone module along a preset trajectory. During the movement of the drone module, the anti-collision airbag of one of the polygonal frames of the protective frame contacts and rolls with the inner wall of the tunnel. The polygonal frame of the system is a plane. During the movement, the drone module drives the flight, and the anti-collision airbag of one of the polygonal frames contacts the inner wall of the tunnel. To make the anti-collision airbag roll more smoothly in all directions, the polygonal frame of the system is equipped with several brackets, each of which is connected to the anti-collision airbag. The brackets can rotate circumferentially on the polygonal frame, and the brackets are perpendicular to the plane of the polygonal frame.

[0018] When the system moves along a preset trajectory, one of the polygonal frames contacts the inner wall of the tunnel, and the anti-collision airbag on the polygonal frame acts as a roller to slide on the inner wall of the tunnel. The direction of airflow in the tunnel, such as the ventilation system or natural airflow, may cause the drone module to fly with or against the wind. The air pressure with or against the wind will reduce the stability of the drone module's flight. In addition, the wind pressure generated by vehicles entering the tunnel will affect the stability of the drone module's flight even if it does not cause the drone module to deflect or collide. However, the system causes one of the polygonal frames to contact the inner wall of the tunnel. During the flight of the drone module, the anti-collision airbag on the polygonal frame acts as a roller to slide on the inner wall of the tunnel. During the rolling process of the anti-collision airbag, the bracket rotates circumferentially, adjusting the direction of movement and making the movement smoother. The system rolls close to the tunnel wall, which can further prevent the influence of wind pressure on the flight stability of the drone module.

[0019] On the other hand, the polygonal frame can be a pentagonal frame, the pentagonal frame is a regular pentagon, the protective frame includes twelve pentagonal frames, and the vertices of each pentagonal frame are connected to three faces to form a regular dodecahedron, that is, the polygonal frame is a regular dodecahedron.

[0020] The polygonal frame can also be a pentagonal frame or a hexagonal frame. The pentagonal frame is a regular pentagon, and the hexagonal frame is a regular hexagon. The protective frame includes twelve pentagonal frames and twenty hexagonal frames. Each pentagonal frame is connected to five hexagonal frames, and each vertex is connected to three faces. The protective frame of this system uses a truncated icosahedron composed of pentagonal frames and hexagonal frames, that is, a 32ohedron. This structure is a convex polyhedron and is a type of Archimedean solid.

[0021] When the hexagonal surface contacts the inner wall, it is less likely to overturn than a triangle or a quadrilateral. The symmetry of the hexagon ensures that the center of gravity is always centered during movement, avoiding the deflection torque caused by the asymmetric structure.

[0022] The geometric properties of a convex polyhedron composed of regular pentagons and hexagons conform to Euler's formula, ensuring uniform force distribution. When a side surface contacts the inner wall, the alternating arrangement of pentagons and hexagons disperses local pressure across more adjacent surfaces, reducing stress concentration. This is particularly true in the protective frame composed of pentagonal and hexagonal frames, where each vertex connects a regular pentagon and two regular hexagons. This symmetrical design ensures more uniform force distribution during rolling or collision.

[0023] Furthermore, during a collision, the multifaceted nature of the polyhedron allows it to disperse impact energy across multiple contact points, reducing the risk of localized damage. When subjected to external forces, its closed structure absorbs energy through the coordinated deformation of its regular pentagons and hexagons, preventing excessive pressure from being placed on a single location. Furthermore, the grooves formed along the polyhedron's edges guide airflow, reducing turbulence and improving flight stability.

[0024] The system also includes an automatic correction module, which is used to return the drone module to the deviation point when the drone module deviates from the preset trajectory at the deviation point.

[0025] Furthermore, an inspection method of a highway tunnel inspection system based on a drone includes the following steps:

[0026] A trajectory is preset in the tunnel, one of the polygonal frames of the protection module is a positioning polygonal frame, and the anti-collision airbag of the positioning polygonal frame contacts the inner wall of the tunnel;

[0027] The camera of the monitoring module acquires images inside the tunnel;

[0028] The path module enables the drone module to move along a preset trajectory. When the drone module deviates from the preset trajectory at a deviation point, the automatic correction module enables the drone module to return to the deviation point and enables the anti-collision airbag of the positioning polygonal frame to contact the inner wall of the tunnel at the deviation point.

[0029] Among them, the preset trajectory is a spray belt set on the inner wall of the tunnel. The monitoring module also includes a multi-view camera and a lidar. The multi-view camera and lidar are used to identify the characteristics of the spray belt in the tunnel and make the positioning polygon frame fly along the center of the spray belt according to the characteristics of the spray belt.

[0030] By setting the preset trajectory to the spray strip sprayed on the inner wall of the tunnel, there is no need to groove or drill holes in the tunnel, which means that the internal structure of the tunnel will not be damaged. By identifying the characteristics of the spray strip in the tunnel, the polygonal frame is moved along the center of the spray strip, which reduces the difficulty of identification and is more conducive to accurate flight.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] The present invention is based on a drone-based highway tunnel inspection system and method, which wraps the drone module and monitoring module in a polyhedron frame. The polyhedron frame and the rolling anti-collision airbags thereon effectively improve the drone's anti-collision performance and flight safety performance. In addition, the system can roll and fly close to the tunnel wall, preventing the vehicle wind pressure from affecting the drone's flight stability.

[0033] The protective frame of this system is a polyhedron frame, which is low-cost and easy to process and assemble. The polyhedron frame of this system can easily pass through the height-restricted area and avoid obstacles in narrow and complex highway tunnels, ensuring that there are no blind spots in the inspection. In addition, the structure of the protective frame of this system can also effectively reduce air resistance, improve flight stability, and realize efficient inspection in a limited space.

[0034] This system allows for rapid tunnel entry and rapid inspections along pre-set inspection routes, covering a large area in a short period of time and significantly improving inspection efficiency. Furthermore, many tunnels present complex environments with hazards such as falls from heights, toxic and hazardous gases, and confined spaces, posing threats to the safety of inspectors. This system replaces manual inspections in these hazardous areas, preventing direct exposure and effectively ensuring the safety of inspectors. For example, in underground cable tunnel inspections, this system can mitigate risks such as electric shock. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0036] Figure 1 This is a schematic diagram of the system structure;

[0037] Figure 2 A schematic diagram of the structure of the protection frame when the polygonal frame is a pentagonal frame and a hexagonal frame;

[0038] Figure 3 A schematic diagram of the anti-collision airbag structure on the protection frame when the polygonal frame is a pentagonal frame and a hexagonal frame;

[0039] Figure 4 A schematic diagram of the structure of the protection frame when the polygonal frame is a pentagonal frame;

[0040] Figure 5 A schematic diagram of the anti-collision airbag structure of the protection frame when the polygonal frame is a pentagonal frame;

[0041] Figure 6 It is a schematic diagram of the structure between the UAV module and the connecting frame;

[0042] Figure 7A schematic diagram of the connection structure between the anti-collision airbag and the bracket;

[0043] Figure 8 It is a front view of the anti-collision airbag;

[0044] Figure 9 A schematic diagram of a structure in which three brackets and an anti-collision airbag are provided on each side of a polygonal frame;

[0045] Figure 10 A schematic diagram of the structure for positioning the polygonal frame moving on the spray belt;

[0046] Markings and corresponding parts names in the accompanying drawings:

[0047] 1-UAV module, 2-monitoring module, 3-connecting frame, 4-protection frame, 5-anti-collision airbag, 6-bracket. DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0049] In the description of the present invention, it should be understood that the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present invention.

[0050] Example 1

[0051] Highway tunnel inspection system based on drones, this system includes Figure 1 As shown, a drone module 1, a monitoring module 2 and a protection module are provided. The monitoring module 2 is provided on the drone module 1 and is used to obtain images and data in the tunnel.

[0052] The monitoring module includes a 4K wide-angle camera, an infrared thermal imager, and a gas / environmental sensor. The 4K wide-angle camera is used to capture images inside the tunnel and detect surface defects such as cracks and exposed steel bars; the infrared thermal imager detects leakage points or abnormal temperature rise in equipment; and the gas / environmental sensor: real-time monitoring of the concentration of hazardous gases such as methane and CO, as well as temperature and humidity, to prevent explosion or corrosion risks.

[0053] In some embodiments, the monitoring module includes a high-definition camera, lidar, and infrared thermal imager, enabling comprehensive, multi-angle, high-precision inspection of the tunnel's internal structures, equipment, and defects, capturing clear and accurate images and data. The monitoring module is an existing monitoring component, and the monitoring module employed by this system may also include other monitoring components. The monitoring module employed by this system is based on existing technology, and the defect detection method is also based on existing methods. For example, cracks, spalling, and other defects can be identified using YOLOv7 or Transformer models, and leakage areas can be located through temperature gradient analysis using thermal imaging data.

[0054] The protection module includes a protection frame 4, which includes several polygonal frames. The protection frame 4 is a polyhedron frame with vertices of several polygonal frames connected to each other. The drone module 1 and the monitoring module 2 are located in the protection frame 4, and the polygonal frames are all provided with several anti-collision airbags 5.

[0055] In some embodiments, a plurality of anti-collision airbags 5 are provided on each side of the polygonal frame, and the distance between two adjacent anti-collision airbags 5 on each side is the same.

[0056] In some embodiments, the structure of the protection frame 4 is as follows: Figure 2 As shown, the polygonal frames are pentagonal frames and hexagonal frames. The pentagonal frames are regular pentagons and the hexagonal frames are regular hexagons. The protective frame 4 includes twelve pentagonal frames and twenty hexagonal frames. Each pentagonal frame is connected to five hexagonal frames, and each vertex is connected to three faces. The polygonal frames are each provided with a plurality of anti-collision airbags 5. Figure 3 shown.

[0057] In some embodiments, the structure of the protection frame 4 is as follows: Figure 4 As shown, the polygonal frame is a pentagonal frame, and the pentagonal frame is a regular pentagon. The protection frame includes twelve pentagonal frames, and the vertices of each pentagonal frame are connected to three faces to form a regular dodecahedron. The polygonal frames are each provided with a plurality of anti-collision airbags 5. Figure 5 shown.

[0058] The drone module 1 and the protection module are connected via a connecting frame 3. The structure between the drone module 1 and the connecting frame 3 is as follows: Figure 6 As shown, one end of the connecting frame 3 is fixedly connected to the drone module 1, and the other end of the connecting frame 3 is fixedly connected to the protective frame 4. The connecting frame 3 can be a triangular support frame or a circular ring.

[0059] When the system is in use, the drone module drives the system to fly in the tunnel. When a collision occurs due to the influence of air pressure, the anti-collision airbags on the polygonal frame contact the collision point to cushion the collision and thus prevent damage to the drone module.

[0060] In some embodiments, the size of the protective frame is adjusted according to the volume of the drone module.

[0061] In some embodiments, the protective frame is made of carbon fiber. Carbon fiber has extremely high specific strength and modulus, meaning it is lightweight yet high in strength. This helps reduce the weight of the bearing and its supporting structure, improving overall performance. Furthermore, carbon fiber exhibits excellent resistance to various environmental factors and is not susceptible to corrosion or damage. It also maintains good performance stability even at high temperatures, making it suitable for high-temperature operating environments.

[0062] Example 2

[0063] On the basis of Example 1, the anti-collision airbag is roller-shaped, and the anti-collision airbag 5 is made of rubber material. An inflation port is provided on the anti-collision airbag 5 for inflating the airbag 5 toward the inside to expand the anti-collision airbag 5 .

[0064] The anti-collision airbag 5 can rotate in the circumferential direction of the polygonal frame. When the anti-collision airbag contacts the collision point, the anti-collision airbag can buffer the impact force through rotation.

[0065] In some embodiments, the polygonal frame is provided with a plurality of brackets 6, to which the anti-collision airbag 5 is connected. The axis of the anti-collision airbag 5 is perpendicular to the straight line where the bracket 6 is located. The center of the circle of the anti-collision airbag 5 is connected to the bracket 6 through a connecting plate. Therefore, the anti-collision airbag 5 can rotate circumferentially along the axis of the anti-collision airbag 5 on the connecting plate.

[0066] In addition, one end of the bracket 6 is connected to the polygonal frame, and the bracket 6 can rotate circumferentially on the polygonal frame. The bracket 6 is perpendicular to the plane where the polygonal frame is located. The anti-collision airbag 5 is located outside the protection frame 4. Specifically, the structure of the anti-collision airbag is as follows Figure 7 and 8 As shown, the bracket 6 is connected to the axis of the anti-collision airbag 5 through a connecting frame, and the connecting frame is connected to the bracket.

[0067] In some embodiments, Figure 9 As shown, three brackets 6 are provided on each side of the polygonal frame, and each bracket 6 is connected to an anti-collision airbag 5 .

[0068] Example 3

[0069] Based on the above embodiment, this system also includes a path module and an automatic correction module. The path module is used to move the drone module 1 along a preset trajectory. During the movement of the drone module 1, the anti-collision airbag 5 of one of the polygonal frames of the protective frame 4 contacts and rolls against the inner wall of the tunnel. The automatic correction module is used to return the drone module 1 to the deviation point if it deviates from the preset trajectory at the deviation point.

[0070] The inspection method of the inspection system includes the following steps:

[0071] A track is preset in the tunnel, one of the polygonal frames of the protection module is a positioning polygonal frame, and the anti-collision airbag 5 of the positioning polygonal frame contacts the inner wall of the tunnel;

[0072] The camera of monitoring module 2 acquires images inside the tunnel;

[0073] The path module enables the drone module 1 to move along a preset trajectory. When the drone module 1 deviates from the preset trajectory at a deviation point, the automatic correction module enables the drone module 1 to return to the deviation point and enables the anti-collision airbag 5 of the positioning polygonal frame to contact the inner wall of the tunnel at the deviation point.

[0074] The preset trajectory is a spray belt set on the inner wall of the tunnel. The monitoring module 2 also includes a multi-view camera and a laser radar. The multi-view camera and the laser radar are used to identify the characteristics of the spray belt in the tunnel and make the positioning polygon frame fly along the center of the spray belt according to the characteristics of the spray belt.

[0075] When the positioning polygonal frame of one of the polygonal frames of the protection frame moves on the spray belt, such as Figure 10 As shown. In this embodiment, the spray strips sprayed in the tunnel are fluorescent yellow or red. The color of the spray strips contrasts sharply with the tunnel background, facilitating rapid identification by the drone camera. The spray strips can be designed as continuous straight lines or specific patterns, such as arrows. The system is equipped with a recognition camera that captures images of the spray strips and extracts their color features through RGB-HSV color space conversion. This is then binarized and processed using a mean filter for noise reduction. The spray strip line equation y = kx + b is fitted using the least squares method. The slope k and intercept b are calculated to obtain the spray strip's yaw angle θ = arctan(k) and lateral offset Δx relative to the drone. Δx = X1 - X2, where X1 is the lateral coordinate of the spray strip centerline and X2 is the lateral coordinate of the image center point of the spray strip image. If θ ≠ 0°, the flight controller adjusts the drone's yaw angle to θ to align with the spray strip's direction. The drone's left and right translation is adjusted based on Δx to maintain its position on the spray strip.

[0076] The flight controller adjusts the drone's attitude in real time based on θ and Δx. Yaw angle correction can be achieved by outputting a servo control variable via a PID controller. Lateral correction can be achieved by adjusting horizontal displacement using proportional control. The specific adjustment methods are based on existing technologies. The path module and automatic correction module can also employ other technologies that enable the drone module 1 to move along the spray belt and return to the point of deviation if it deviates, ensuring that the anti-collision airbag 5 of the positioning polygonal frame contacts the tunnel wall at the point of deviation.

[0077] The preset trajectory can be achieved through a variety of methods. For example, the path module uses a laser scanner or SLAM technology to construct a three-dimensional point cloud model of the tunnel and mark key inspection points such as pipe segment joints and cable brackets. No-fly zones such as equipment-intensive areas are divided and detour points are set to generate detour track segments. A greedy algorithm is used to generate an initial path, such as the shortest traversal of all inspection points. The path sequence is then adjusted through an optimization algorithm such as brainstorming optimization (BSO). If there are obstacles on the straight path, the obstacle avoidance radius is calculated and the cut-out point is selected to correct the path. In addition, algorithms based on graph theory and reinforcement learning are used to ensure that the drone module's protective frame can avoid obstacles and successfully reach the target position during flight. This algorithm is an existing algorithm and the inventor will not elaborate on it here.

[0078] The routing module can also generate a 3D tunnel model during tunnel construction or maintenance using BIM models or LiDAR scans. The model pre-sets the spray route coordinates, establishing a fixed coordinate system with the tunnel entrance as the origin, along the tunnel axis as the X-axis, vertically as the Z-axis, and horizontally as the Y-axis. Track point spatial coordinates are generated based on inspection requirements, such as height and spacing.

[0079] The terms "first," "second," and "third" used herein are merely used to distinguish corresponding components for clarity of description and are not intended to limit any order or emphasize importance. In addition, the term "connected" used herein, unless otherwise specified, may refer to a direct connection or an indirect connection via other components.

[0080] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. The highway tunnel inspection system based on drones is characterized by: A drone module (1), a monitoring module (2) and a protection module, wherein the monitoring module (2) is arranged on the drone module (1), and the monitoring module (2) is used to obtain images and data in the tunnel; The protection module includes a protection frame (4), which includes a plurality of polygonal frames. The protection frame (4) is a polyhedron frame in which the vertices of the plurality of polygonal frames are interconnected. The drone module (1) and the monitoring module (2) are located in the protection frame (4), and the polygonal frames are each provided with a plurality of anti-collision airbags (5).

2. The UAV-based highway tunnel inspection system according to claim 1 is characterized in that: The anti-collision airbag (5) can rotate in the circumferential direction of the polygonal frame.

3. The UAV-based highway tunnel inspection system according to claim 1 is characterized in that: The system further comprises a path module, which is used to enable the drone module (1) to move along a preset track. During the movement of the drone module (1), the anti-collision airbag (5) of one of the polygonal frames of the protection frame (4) contacts and rolls against the inner wall of the tunnel.

4. The UAV-based highway tunnel inspection system according to claim 1 is characterized in that: The polygonal frames are each provided with a plurality of brackets (6), the brackets (6) being connected to anti-collision airbags (5), the anti-collision airbags (5) being able to rotate circumferentially on the brackets (6), and the brackets (6) being able to rotate circumferentially on the polygonal frame, and the brackets (6) being perpendicular to the plane where the polygonal frame is located.

5. The highway tunnel inspection system based on drone according to claim 1 is characterized in that: The polygonal frame is a pentagonal frame, and the pentagonal frame is a regular pentagon.

6. The highway tunnel inspection system based on drone according to claim 1 is characterized in that: The polygonal frame includes a pentagonal frame and a hexagonal frame. The pentagonal frame is a regular pentagon, and the hexagonal frame is a regular hexagon.

7. The UAV-based highway tunnel inspection system according to claim 1 is characterized in that: A plurality of anti-collision airbags (5) are provided on each side of the polygonal frame, and the distance between two adjacent anti-collision airbags (5) on each side is the same.

8. The highway tunnel inspection system based on drone according to claim 1 is characterized in that: The system further comprises an automatic correction module, which is used to return the drone module (1) to the deviation point when the drone module (1) deviates from a preset trajectory at the deviation point.

9. The inspection method of the highway tunnel inspection system based on drones is characterized by: The inspection system according to any one of claims 1 to 8 is provided, wherein the inspection method of the inspection system comprises the following steps: A trajectory is preset in the tunnel, one of the polygonal frames of the protection module is a positioning polygonal frame, and the anti-collision airbag (5) of the positioning polygonal frame contacts the inner wall of the tunnel; The camera of the monitoring module (2) acquires images inside the tunnel; The path module enables the drone module (1) to move along a preset track. When the drone module (1) deviates from the preset track at a deviation point, the automatic correction module enables the drone module (1) to return to the deviation point and enables the anti-collision airbag (5) of the positioning polygonal frame to contact the inner wall of the tunnel at the deviation point.

10. The inspection method of the highway tunnel inspection system based on a drone according to claim 9, characterized in that: The preset trajectory is a spray belt set on the inner wall of the tunnel. The monitoring module (2) also includes a multi-view camera and a laser radar. The multi-view camera and the laser radar are used to identify the characteristics of the spray belt in the tunnel and make the positioning polygon frame fly along the center of the spray belt according to the characteristics of the spray belt.

Images