Spider wall climbing detection robot with geological radar

Abstract

The application provides a spider type wall climbing detection robot loaded with a geological radar, relates to the field of tunnel lining nondestructive testing technology, and comprises an octagonal central body main body, six groups of mechanical leg assemblies, a vacuum adsorption system, a loading frame and a geological radar antenna module; the six groups of mechanical leg assemblies are uniformly installed on the side planes of the central body main body, and the tail ends are provided with vacuum adsorbers with flexible buffer members; the loading frame is fixedly connected to one side of the central body main body and extends to the wall surface of the tunnel lining; the geological radar antenna module is inserted into the U-shaped support frame of the loading frame through a positioning guide rod and is locked through an antenna handle fixing device; the application can directly transmit the vacuum adsorption force to the detection surface, and the high rigidity locking structure of the U-shaped support frame and the six-legged triangular gait adsorption logic can solve the problems of high gravity center, the need of a complex posture adjusting mechanism, poor obstacle crossing stability and insufficient safety of the existing device.

Description

Technical Field

[0001] This invention belongs to the field of non-destructive testing technology for tunnel lining, and in particular, it is a spider-like wall-climbing inspection robot equipped with ground-penetrating radar. Background Technology

[0002] Tunnel lining quality is a core guarantee for operational safety, and ground-penetrating radar (GPR) has become the mainstream detection method due to its non-destructive and efficient characteristics. Currently, most wall-climbing robots equipped with GPR adopt wheeled / tracked walking mechanisms or biomimetic leg structures, but existing solutions still have many shortcomings.

[0003] For example, utility model patent CN216670296U discloses a biomimetic walking tunnel lining void non-destructive testing device, which adopts a four-legged structure, with the feet adhering to the wall surface via vacuum negative pressure suction cups, and the antenna mounted on the upper surface of the testing module. This solution still has the following shortcomings: First, the antenna's placement on the upper surface of the testing module results in a high center of gravity, leading to a large overturning moment during inverted operation and requiring extremely high suction force from the suction cups. Additionally, it necessitates the addition of elevation and axial servo motors to adjust the antenna angle to adapt to the tunnel's curved surface, increasing the complexity and weight of the mechanism. Crawling vibrations can easily cause the testing angle to drift. Second, the testing module uses an integrated box structure with no partitioning or isolation of internal components. The battery, control motherboard, and vacuum pump are mixed together, resulting in poor electromagnetic compatibility and insufficient heat dissipation design, making it prone to overheating failures during prolonged operation. Third, the four-legged structure has limited support stability. When crossing tunnel circumferential joints or uneven obstacles, it is prone to swaying due to insufficient support surface, which in turn affects the antenna fit. In addition, the solution does not have a safety redundancy mechanism for adsorption. If a single suction cup leaks air, there is a risk of the whole unit falling.

[0004] To address the aforementioned issues, there is an urgent need for a wall-climbing inspection robot that features a low center of gravity, simplified structure, high stability, and good safety. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a spider-like wall-climbing inspection robot equipped with ground-penetrating radar. Through the central body of the regular octagonal frame, the six-legged distributed layout, and the design of the ground-penetrating radar antenna being attached to the bottom, the present invention solves the problems of high center of gravity, need for additional attitude adjustment gimbal, poor support stability, and insufficient safety redundancy of existing devices.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A spider-like wall-climbing inspection robot equipped with ground-penetrating radar includes a central body, mechanical leg assemblies, a vacuum adsorption system, a mounting frame, and a ground-penetrating radar antenna module. The central body is a frame-type cylindrical structure with a regular octagonal cross-section, forming an internal cavity. Six sets of mechanical leg assemblies are circumferentially fixed to six side planes of the regular octagonal frame, with the fixing points of the six sets of mechanical leg assemblies diagonally distributed about the central axis of the central body. Each set of mechanical leg assemblies includes at least three joint servo motors and an end vacuum suction cup mounted at its end. The vacuum adsorption system is located inside the central body and is connected to the end vacuum suction cup via a pipeline. The mounting frame is fixed to the lower surface of the central body and extends towards the tunnel lining wall. The ground-penetrating radar antenna module is detachably fixed within the mounting frame, with its detection surface facing the tunnel lining wall. Structurally, the mounting frame positions the ground-penetrating radar antenna module at the foremost point of the robot in the direction facing the wall. When operating upside down on the tunnel arch, the suction force generated by the vacuum adsorption system is directly transmitted to the ground-penetrating radar antenna module through the central body, forcing the detection surface to fit tightly against the tunnel lining wall, eliminating the need for an additional antenna adjustment mechanism. During operations on the sidewalls and arch waist, the machine's own weight further enhances the fit.

[0007] Furthermore, the mounting frame includes a U-shaped support frame, which has a rear wall, two opposing side walls, and an open end. The ground-penetrating radar antenna module is provided with a positioning guide rod, which is inserted between the two side walls of the U-shaped support frame. The mounting frame also includes an antenna handle fixing device, which is disposed at the open end of the U-shaped support frame and configured to apply a releasable clamping limit to the positioning guide rod to restrict the displacement of the ground-penetrating radar antenna module.

[0008] Technical Benefits: The combination of a U-shaped support frame and a positioning guide rod enables rapid and accurate positioning of the ground-penetrating radar antenna module. The positioning guide rod is inserted between the two side walls of the support frame, restricting the antenna module's translational freedom in the horizontal plane. The antenna handle fixing device (such as a wing bolt or quick clamp) located at the opening locks the positioning guide rod, further restricting the antenna module's displacement freedom. This method of side wall support and end-locking fixation forms an extremely stable rigid connection, effectively resisting the impact and vibration caused by uneven tunnel walls, ensuring the antenna detection surface remains in close contact with the wall, significantly improving the signal-to-noise ratio of the detection data. Furthermore, this structure allows for quick, manual replacement of the antenna module by a single person, improving on-site operational efficiency.

[0009] Furthermore, the at least three joint servos specifically include: a hip joint servo, a knee joint servo, and an ankle joint servo; the hip joint servo housing is fixed to the side plane of the central fuselage body; one end of the thigh link is connected to the output end of the hip joint servo, and the other end of the thigh link is connected to the knee joint servo housing; one end of the middle leg link is connected to the output end of the knee joint servo, and the other end of the middle leg link is connected to the ankle joint servo housing; one end of the lower leg link is connected to the output end of the ankle joint servo, and the other end of the lower leg link is equipped with the end vacuum suction cup.

[0010] Technical benefits: This three-degree-of-freedom design gives the mechanical leg extremely high flexibility, enabling it to adapt to the complex curvature of the tunnel wall like a spider's legs, easily crossing circumferential joints and local protrusions, overcoming the shortcomings of wheeled or tracked mechanisms that are prone to slipping and getting stuck on complex walls.

[0011] Furthermore, a flexible buffer is provided between the end vacuum suction cup and the lower leg connecting rod. The flexible buffer is an axial compression spring assembly or an elastic damping sleeve, so that the end vacuum suction cup has an axial floating stroke relative to the lower leg connecting rod to adapt to the local unevenness of the tunnel lining wall.

[0012] Technical benefits: The axial floating stroke design is equivalent to adding a flexible joint between the suction cup and the rigid connecting rod. When the suction cup contacts the wall or crawls over a rough surface, the flexible buffer can absorb the impact vibration and automatically compensate for the micro-unevenness of the wall, ensuring that the suction cup lip is always in close contact with the wall, preventing air leakage or detachment caused by hard impact, and significantly improving the reliability of adsorption.

[0013] Furthermore, the vacuum adsorption system includes a miniature vacuum pump, a controller, and six solenoid valves, each of which is connected to the suction passage of one of the end vacuum suction cups. The controller is electrically connected to the six solenoid valves and is configured to drive the six solenoid valves in a diagonally grouped, alternating on and off manner, so that at any given time, at least three end vacuum suction cups located in non-collinear positions maintain negative pressure adsorption.

[0014] Technical effects: The zoned on / off control realizes biomimetic gait (such as triangular gait); the algorithm ensures that at least three feet are firmly attached to the wall at any time, forming a stable support triangle; thus not only reducing the load on a single suction cup, but more importantly, when crossing obstacles or when there is a leak in one path, the remaining suction cups can still provide sufficient suction force, forming a very high safety redundancy and solving the problem of insufficient suction stability in existing technologies.

[0015] Furthermore, the central body includes a supporting frame and an outer shell. The supporting frame is a regular octagonal frame milled from aluminum alloy, and the outer shell is a carbon fiber composite material plate fixedly connected to the outer surface of the supporting frame. The accommodating cavity is provided with battery placement positions, main control board placement positions, and pump placement positions separated by internal partitions. The micro vacuum pump is housed in the pump placement position, the main control board is housed in the main control board placement position, and the battery is housed in the battery placement position. The central body also has bottom ventilation holes and top heat dissipation holes, with the bottom ventilation holes communicating with the top heat dissipation holes to form an air convection channel.

[0016] Technical advantages: The split structure of aluminum alloy frame and carbon fiber shell greatly reduces the weight of the whole machine while ensuring the strength of the main load-bearing structure; the modular partition layout formed by the built-in partitions effectively isolates electromagnetic interference between the battery, control motherboard and vacuum pump, improving system stability; at the same time, the ventilation holes running through the top and bottom form a chimney effect heat dissipation channel, which can timely dissipate the heat generated by high load operation, avoid overheating failure of electronic components, and meet the needs of long-term continuous operation in tunnels.

[0017] Furthermore, it also includes: A vacuum sensor is installed on the pipeline of the vacuum adsorption system (3) or in the suction chamber of any of the end vacuum suction cups (7) to detect the negative pressure value; A security alarm; and A main control board is housed in the central body (1), and the main control board is electrically connected to the vacuum sensor, the safety alarm and the solenoid valve of the vacuum adsorption system (3); When the negative pressure value detected by the vacuum sensor is lower than a preset safety threshold, the main control board is configured to trigger the safety alarm and issue a valve locking command to maintain the current adsorption state; the central body is also equipped with a fall arrestor ring, which is used to connect a safety rope.

[0018] Technical benefits: The vacuum sensor constitutes an active safety monitoring system. Once it detects that the adsorption force is lower than the safety threshold (such as when the suction cup is damaged or there is a serious air leak), the system can immediately trigger an audible and visual alarm and lock the valve to maintain the residual vacuum, giving the operator time to deal with the situation. Combined with the passive protection consisting of physical fall arrest rings and safety ropes, it forms a dual safety guarantee combining hardware and software, which is particularly suitable for high-risk working environments such as tunnel arches.

[0019] Furthermore, it also includes: a lighting lamp, which is fixed to the bottom of the central fuselage body and located on the side of the mounting frame (4), with its light-emitting surface tilted downward toward the side where the detection surface of the ground-penetrating radar antenna module is located, so as to illuminate the wall area in front of the antenna when crawling.

[0020] Technical benefits: The lighting follows the robot, directly illuminating the area to be inspected in front of the antenna, solving the problem of blind spots caused by dim lighting in the tunnel. This makes it easier for operators to remotely observe road conditions and equipment status, while also providing a light source for visual-assisted navigation, thus improving the safety and controllability of the operation.

[0021] The beneficial effects of this invention are: 1. This invention fixes the ground-penetrating radar antenna module to the foremost front of the fuselage facing the wall via a mounting frame. In the case of an inverted arched roof, the vacuum adsorption force acts directly on the fuselage and rigidly presses the antenna against the wall, eliminating the need for complex attitude adjustment mechanisms such as elevation servo motors and axial servo motors required in existing technologies. In the case of an inclined arch or a vertical side wall, the antenna is positioned closest to the wall, achieving zero-cantilever stable detection in conjunction with the adsorption force and gravity component. This design of direct adsorption force transmission eliminates the gaps and vibrations caused by multi-stage transmission, significantly improving detection accuracy. 2: Since the ground-penetrating radar antenna module and mounting frame are located at the bottom of the fuselage (facing the wall), the center of gravity of the whole machine is extremely close to the wall, which greatly reduces the overturning moment during inverted operation and reduces the requirements for the suction force of the vacuum suction cup. Under the same suction capacity, it has a higher safety redundancy and effectively prevents the risk of falling from a height. 3. The mounting frame adopts a slot-type design with a U-shaped support frame and a positioning guide rod. The positioning guide rod is inserted into the two side walls of the support frame to achieve automatic horizontal centering. The locking device at the open end (such as a wing bolt) directly acts on the positioning guide rod, restricting the translational freedom of the antenna module. This effectively resists the impact and vibration caused by uneven tunnel walls, prevents the antenna from jumping off when crossing circumferential joints, and ensures continuous and tight contact between the detection surface and the wall. At the same time, this structure allows a single person to quickly change antenna modules of different frequencies by hand, which greatly improves the efficiency of on-site operations. 4. The octagonal frame, combined with six sets of mechanical leg components and a zoned control logic that always maintains at least three suction cups, results in extremely high gait stability and a smooth posture when crossing obstacles. The central body adopts a split structure with an aluminum alloy frame and a carbon fiber shell. The interior is divided into independent battery, main control board, and pump compartments by built-in partitions, which not only avoids electromagnetic interference but also utilizes the vertical ventilation holes to form an efficient chimney effect heat dissipation channel, adapting to the needs of long-term continuous operation in tunnels. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a side view of the entire machine of the present invention; Figure 3 This is a bottom view of the entire machine of the present invention; Figure 4 This is a top view of the entire machine of the present invention; Figure 5 This is a schematic diagram of the internal cross-sectional structure of the central fuselage body in this invention; Figure 6 This is a schematic diagram of the structure supporting the frame; Markings in the diagram: 1. Central fuselage main body; 1a. Bottom ventilation hole; 2. Mechanical leg assembly; 2a. Hip joint servo; 2b. Knee joint servo; 2c. Ankle joint servo; 3. Vacuum adsorption system; 4. Mounting frame; 4a. Antenna handle fixing device; 5. Ground penetrating radar antenna module; 6. Thigh linkage; 7. End vacuum suction cup; 8. Fall arrestor ring; 9. Top heat dissipation hole; 17. Middle leg linkage; 18. Lighting light; 20. Flexible buffer; 21. Battery placement position; 22. Main control board placement position; 23. Pump placement position; 24. Internal partition. Detailed Implementation

[0023] like Figures 1 to 6 As shown, this embodiment is a standard implementation of a spider-like wall-climbing inspection robot equipped with ground-penetrating radar, which is applicable to the lining inspection scenarios of most highways and railway tunnels.

[0024] The central fuselage body 1 is a frame-type cylindrical structure with a regular octagonal cross-section. The load-bearing frame is milled from 7075-T6 aluminum alloy to ensure the strength and rigidity of the main load-bearing structure. The outer surface is bolted with carbon fiber composite plates as the shell, which significantly reduces the overall weight of the machine while ensuring structural strength. The interior of the central fuselage body 1 is divided into three independent compartments by an internal partition 24: the battery placement compartment 21 is used to house a 24V lithium battery pack to power the main control system, joint servo motor, and vacuum pump; the main control board placement compartment 22 is used to install the core control motherboard, which integrates gait planning, data acquisition, and wireless communication functions; and the pump placement compartment 23 is used to install two parallel KVP-12 miniature vacuum pumps. The top of the central fuselage body 1 has a top heat dissipation hole 9, and the bottom has a bottom ventilation hole 1a. The corresponding positions of the two form an air convection channel (chimney effect) to quickly dissipate the heat generated by the pumps and the main control board, ensuring stability during long-term operation.

[0025] Mechanical leg assembly 2: There are six sets in total. The six sets of mechanical leg assemblies 2 are fixed to six side planes of the regular octagonal frame at intervals along the circumference, and the fixing points of the six sets of mechanical leg assemblies 2 are diagonally distributed about the central axis of the central fuselage body 1. Each mechanical leg assembly 2 includes three joint servos, and the rotation axes of the three joint servos on each mechanical leg assembly 2 are parallel to the corresponding mounting side plane. Among the three joint servos, the housing of the hip joint servo 2a is fixed to the side plane of the central body 1 by bolts, and its output shaft is rigidly connected to one end of the thigh link 6, which can drive the entire leg to swing in the horizontal plane; the other end of the thigh link 6 is fixed to the housing of the knee joint servo 2b, and its output shaft is rigidly connected to one end of the middle leg link 17, which can drive the lower leg to complete flexion and extension movements; the other end of the middle leg link 17 is fixed to the housing of the ankle joint servo 2c, and its output shaft is rigidly connected to one end of the lower leg link, which can adjust the posture of the end vacuum suction cup 7 to adapt to the wall angle. The end vacuum suction cup 7 is installed at the end of the lower leg connecting rod via a connector. A flexible buffer 20 is sleeved on the outside of the connector. In this embodiment, the flexible buffer 20 is an axial compression spring made of 60Si2Mn spring steel. One end of the spring abuts against the end of the lower leg connecting rod, and the other end abuts against the back of the vacuum suction cup. It can provide an axial floating stroke of 10-15mm. When the suction cup contacts the wall surface, it can adapt to the micro-concavity and convexity to ensure fit and sealing.

[0026] Vacuum adsorption system 3: consists of two miniature vacuum pumps, six high-frequency solenoid valves, vacuum tubing, and a vacuum sensor. Figure 5 The diagram only shows the location of the vacuum adsorption system 3, without showing its specific internal structure. Six solenoid valves independently control the on / off states of the vacuum suction cups 7 at the ends of the six sets of mechanical legs. The main control board runs a triangular gait algorithm, maintaining three diagonally distributed suction cups in a negative pressure adsorption state throughout the crawling process, while the other three suction cups are de-vacuumed and lifted to take steps. This alternating cycle ensures stable support triangles for the entire machine at all times. A vacuum sensor is installed on the vacuum pipeline to monitor the vacuum level in real time. When the vacuum level drops below the safety threshold of -40 kPa, the main control board immediately triggers the audible and visual alarm on the anti-fall ring 8, simultaneously locking the on / off states of all solenoid valves to maintain the current adsorption force and prevent the entire machine from slipping and falling. The air pipeline uses polyurethane elastic hoses, which converge along the top surface inside the central fuselage body 1 and then pass through branch joints to each side plane. The pipeline then follows the following path: a through hole is opened in the side wall of the housing of the hip joint servo 2 to enter the inner cavity of the upper arm link 6, and transitions through the first rotary air pipe joint at the hip joint hinge; after exiting the inner cavity of the upper arm link 6, it turns through the second rotary air pipe joint at the knee joint servo 2b to enter the inner cavity of the forearm link 17, and finally exits from the housing of the ankle joint servo 2c to connect to the suction port of the end vacuum suction cup 7; the pipeline margin at each joint is constrained by spiral winding or corrugated sleeve.

[0027] Mounting frame 4 and ground-penetrating radar antenna module 5: Mounting frame 4 has four sets arranged in a rectangular shape. Its U-shaped support frame is an aluminum alloy plate forming a U-shaped structure, which is rigidly fixed to the lower surface of the central body 1 by bolts. The U-shaped support frame has a rear wall and two opposite side walls. The inner side of the side walls is machined with guide rail grooves. The ground-penetrating radar antenna module 5 is fixed with a cylindrical positioning guide rod (i.e., the grip rod of the antenna handle). During installation, the operator holds the ground-penetrating radar antenna module 5 and pushes it inward with the positioning guide rods on both sides aligned with the opening end of the U-shaped support frame until the positioning guide rods abut against the rear wall of the U-shaped support frame. At this time, the guide rail groove limits the positioning guide rod. Then, tighten the U-shaped support frame. The antenna handle fixing device 4a at the open end (in this embodiment, a wing bolt) has its screw rod pressing against the positioning guide rod, thereby locking the positioning guide rod in the guide rail groove, achieving a high-rigidity locking installation of the ground-penetrating radar antenna module 5. The rear end of the ground-penetrating radar antenna module 5 is provided with a standard N-type / SMA-type radio frequency interface. A flexible radio frequency coaxial cable is led out from this interface, passes along the side of the mounting frame 4, is gathered by a cable restraint, and then passes into the interior of the central body 1, connecting to the radar acquisition unit housed in the main control board placement position 22. The cable restraint is configured to provide slack during the swinging of the mechanical leg assembly 2 to avoid tensile fatigue. When the machine is in crawling operation mode, the detection surface of the ground-penetrating radar antenna module 5 is set facing the tunnel lining wall. The detection surface is located at the front end of the machine in the direction facing the tunnel lining wall and is directly attached to the tunnel lining wall. No matter whether the robot is on the tunnel side wall (vertical wall) or the arch (inverted wall), the ground-penetrating radar antenna module 5 is always located on the side of the machine closest to the wall.

[0028] Auxiliary System: A fall arrestor ring 8 is fixed to the top of the central main body 1. During operation, it is connected to a pre-installed anchor rod at the top of the tunnel via a high-strength safety rope, serving as a second layer of fall protection. LED lights 18 are fixed to the bottom of the central main body 1 and to the side of the mounting frame 4. The light emitted is directed towards the front of the ground-penetrating radar antenna module 5, providing sufficient illumination in the dark tunnel environment and ensuring a clear field of view for detection.

[0029] The working principle of this invention is as follows: During operation, the operator moves the robot to the tunnel lining testing area using the handle on the top of the central main body 1; after turning on the power switch, the vacuum adsorption system 3 starts, and the six sets of end vacuum suction cups 7 sequentially adsorb onto the wall surface; when operating on the inverted arch, the adsorption force generated by the vacuum adsorption system 3 overcomes the weight of the entire machine, pulling the central main body 1 and the mounting frame 4 fixed to its lower part together toward the tunnel wall; since the ground-penetrating radar antenna module 5 is located at the front end of the entire machine in the direction facing the wall, its detection surface is passively and rigidly pressed against the lining wall as the machine body is pulled by the adsorption force, without the need for attitude adjustment by elevation or axial servo motors throughout the process; when operating on inclined arches or vertical sidewalls... During operation, in addition to the adsorption force, the component of the robot's own weight perpendicular to the wall also acts on the ground-penetrating radar antenna module 5, further enhancing the stability of the contact between the detection surface and the wall. The main control board drives the six sets of mechanical leg components 2 to move in a triangular gait, and the robot crawls along the planned path. At the same time, the ground-penetrating radar antenna module 5 adheres tightly to the wall under its own weight and emits high-frequency electromagnetic waves into the lining. The received reflected signals are processed by the main control board and then wirelessly transmitted to the ground monitoring terminal. Technicians analyze the waveform to determine whether there are defects such as voids or insufficient thickness inside the lining. If abnormalities such as vacuum leakage occur, the audible and visual alarm will sound immediately, and the operator can use a safety rope to assist in the recovery of the robot to ensure operational safety.

[0030] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A spider-like wall-climbing inspection robot equipped with ground-penetrating radar, characterized in that, include: The central fuselage body (1) is a frame-type cylindrical structure with a cross-section of a regular octagon, and its interior forms a receiving cavity; Six sets of mechanical leg assemblies (2) are fixed to six side planes of the regular octagonal frame at intervals along the circumference, and the fixing points of the six sets of mechanical leg assemblies (2) are diagonally distributed about the central axis of the central fuselage body (1). Each set of mechanical leg assemblies (2) includes at least three joint servo motors and an end vacuum suction cup (7) installed at the end. The vacuum adsorption system (3) is located inside the central body (1) and is connected to the end vacuum suction cup (7) through a pipeline; The mounting frame (4) is fixed to the lower surface of the central fuselage body (1) and extends towards the tunnel lining wall; and The ground-penetrating radar antenna module (5) is detachably fixed inside the mounting frame (4); The detection surface of the ground-penetrating radar antenna module (5) is set facing the tunnel lining wall; and in the assembled state, the detection surface is located on the side of the central fuselage body (1) closest to the wall.

2. The spider-like wall-climbing inspection robot equipped with ground-penetrating radar according to claim 1, characterized in that: The mounting frame (4) includes a U-shaped support frame, which has a rear wall, two opposing side walls, and an open end; The ground-penetrating radar antenna module (5) is provided with a positioning guide rod, which is inserted between the two side walls of the U-shaped support frame; The mounting frame (4) also includes an antenna handle fixing device (4a), which is located at the open end of the U-shaped support frame and is configured to apply a releasable clamping limit to the positioning guide rod to limit the displacement of the ground-penetrating radar antenna module (5).

3. The spider-like wall-climbing inspection robot equipped with ground-penetrating radar according to claim 1, characterized in that, The at least three joint servos specifically include: A hip joint servo motor (2a) has its housing fixedly attached to the side plane of the central fuselage body (1), and its output end is rigidly connected to one end of the thigh linkage (6); A knee joint servo (2b), the housing of which is fixed to the end of the thigh link (6) away from the hip joint servo (2a); Ankle joint servo (2c), the housing of which is fixed to the end of the middle leg link (17) away from the knee joint servo (2b); One end of the thigh link (6) is connected to the output end of the hip joint servo (2a), and the other end of the thigh link (6) is connected to the knee joint servo (2b); One end of the middle leg link (17) is connected to the output end of the knee joint servo (2b), and the other end of the middle leg link (17) is connected to the ankle joint servo (2c); The lower leg link has one end connected to the output end of the ankle joint servo (2c) and the other end of the lower leg link is equipped with the end vacuum suction cup (7).

4. The spider-like wall-climbing inspection robot equipped with ground-penetrating radar according to claim 3, characterized in that, A flexible buffer (20) is provided between the end vacuum suction cup (7) and the lower leg connecting rod. The flexible buffer (20) is an axial compression spring assembly or an elastic damping sleeve, so that the end vacuum suction cup (7) has an axial floating stroke relative to the lower leg connecting rod to adapt to the local unevenness of the tunnel lining wall.

5. The spider-like wall-climbing inspection robot equipped with ground-penetrating radar according to claim 1, characterized in that, The vacuum adsorption system (3) includes a miniature vacuum pump, a controller, and six solenoid valves. Each solenoid valve is connected to the suction passage of one of the end vacuum suction cups (7). The controller is electrically connected to the six solenoid valves and is configured to drive the six solenoid valves in a diagonally grouped alternating on / off manner, so that at any given time, at least three end vacuum suction cups located in non-collinear positions maintain negative pressure adsorption.

6. The spider-like wall-climbing inspection robot equipped with ground-penetrating radar according to claim 1, characterized in that, The central fuselage body (1) includes a supporting frame and an outer shell. The supporting frame is a regular octagonal frame milled from aluminum alloy, and the outer shell is a carbon fiber composite material plate fixedly connected to the outer surface of the supporting frame. The cavity is provided with a battery placement position (21), a main control board placement position (22) and a pump placement position (23) that are separated from each other by an internal partition (24). The miniature vacuum pump is housed in the pump placement position (23), the control motherboard is housed in the main control board placement position (22), and the battery is housed in the battery placement position (21). The central fuselage body (1) is also provided with a bottom ventilation hole (1a) and a top heat dissipation hole (9). The bottom ventilation hole (1a) and the top heat dissipation hole (9) are connected to form an air convection channel.

7. The spider-like wall-climbing inspection robot equipped with ground-penetrating radar according to claim 1, characterized in that, Also includes: A vacuum sensor is installed on the pipeline of the vacuum adsorption system (3) or in the suction chamber of any of the end vacuum suction cups (7) to detect the negative pressure value; A safety alarm; as well as A main control board is housed in the central body (1), and the main control board is electrically connected to the vacuum sensor, the safety alarm and the solenoid valve of the vacuum adsorption system (3); When the negative pressure value detected by the vacuum sensor is lower than a preset safety threshold, the main control board is configured to trigger the safety alarm and issue a valve lock command to maintain the current adsorption state. The central fuselage body (1) is also provided with a fall arrest ring (8), which is used to connect a safety rope.

8. The spider-like wall-climbing inspection robot equipped with ground-penetrating radar according to claim 1, characterized in that, Also includes: The lighting lamp (18) is fixed to the bottom of the central fuselage body (1) and located on the side of the mounting frame (4). Its light-emitting surface is tilted downward toward the detection surface of the ground-penetrating radar antenna module (5) to illuminate the wall area in front of the antenna when crawling.

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