An air-ground cooperative tethered inspection robot for a subway tunnel

Abstract

The air-ground cooperative tethering inspection robot and method for subway tunnels relate to the fields of unmanned systems and rail transit operation and maintenance technologies. The present application is to solve the problems of short endurance time, poor spatial positioning accuracy and high risk of collision in limited space of the existing subway tunnel inspection unmanned aerial vehicle. The present application comprises an air-ground dual-mode unmanned aerial vehicle, a nest and a rail car body. The top of the rail car body is provided with the nest, and the air-ground dual-mode unmanned aerial vehicle is arranged in the nest. The rail car body and the air-ground dual-mode unmanned aerial vehicle perform air-ground follow-up cooperative operation according to a preset inspection path. The air-ground dual-mode unmanned aerial vehicle takes off from the nest during the air-ground cooperative inspection of the subway tunnel, and the air-ground dual-mode unmanned aerial vehicle is connected with the cable winding and unwinding mechanism in the air-ground dual-mode unmanned aerial vehicle. The present application is used for air-ground cooperative tethering inspection of subway tunnels.

Description

Technical Field

[0001] This invention relates to the field of unmanned systems and rail transit operation and maintenance technology, specifically to an air-ground collaborative tethered inspection robot for subway tunnels. Background Technology

[0002] As a critical infrastructure for urban transportation, the structural safety inspection of subway tunnels is of paramount importance. Multi-rotor drones, with their three-dimensional maneuverability, offer a new method for high-level and blind-spot inspection of tunnels, but they still face the following technical challenges in the complex tunnel environment:

[0003] 1. Energy Bottlenecks and Endurance Limitations: Multi-rotor UAVs are limited by battery capacity, making it difficult to support long-duration tunnel inspection missions. Although tethered power supply technology can provide continuous power, during dynamic inspections, if the ground platform cannot achieve high-precision synchronization with the UAV in the air, tension fluctuations or entanglement of the tethered cable will seriously affect flight stability and the safety of power transmission. Therefore, establishing a high-precision air-to-ground homing mechanism to ensure the mechanical stability of the cable during dynamic resupply is crucial for achieving reliable long-term inspections.

[0004] 2. Signal Loss and Attitude Drift: Satellite navigation signals cannot be received in subway tunnels, resulting in severe cumulative positioning errors for UAVs in confined environments. Current inspection methods lack a stable spatial reference. The key to achieving autonomous inspection lies in how to utilize a tracked chassis with precisely known coordinates as a reliable attitude reference source in structured environments lacking satellite signals, and how to eliminate dead reckoning drift of UAVs through air-ground cooperative compensation algorithms.

[0005] Therefore, this application provides an air-ground cooperative tethered inspection system that can provide continuous power supply and uses the track chassis as a spatial orientation reference to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to solve the problems of short flight time, poor spatial positioning accuracy, and high risk of collision in confined spaces in existing subway tunnel inspection drones, and to provide an air-ground collaborative tethered inspection robot and method for subway tunnels.

[0007] The technical solution adopted by the present invention to solve the above problems is: an air-ground cooperative tethered inspection robot for subway tunnels, comprising an air-ground dual-mode UAV, a nest, and a railcar body; the nest is installed on the top of the railcar body, and the air-ground dual-mode UAV is set inside the nest; the railcar body and the air-ground dual-mode UAV perform air-ground cooperative operations according to a preset inspection path; during the air-ground cooperative inspection of the subway tunnel, the air-ground dual-mode UAV takes off from the nest, and the air-ground dual-mode UAV and the railcar body are connected by a tethered cable.

[0008] Furthermore, the air-to-ground dual-mode UAV includes an onboard control unit, a carbon fiber frame, and a power assembly installed at the center of the UAV; the carbon fiber frame is symmetrically arranged on both sides of the onboard control unit; and the power assembly is installed at the far end of the middle of the carbon fiber frame.

[0009] Furthermore, the power assembly includes a motor mounting plate, a brushless motor vertically connected to both ends of the motor mounting plate, and a propeller connected to the motor output shaft; the motor mounting plate is connected to the carbon fiber frame via a carbon rod clamp, and the motor mounting plate and the carbon fiber frame are vertically arranged.

[0010] Furthermore, the air-to-ground dual-mode UAV also includes a rolling protective roller and a self-lubricating bushing. The rolling protective roller includes two sets of roller-type cage-like structures with honeycomb-shaped weight-reducing holes. The self-lubricating bushing is symmetrically installed at both ends of the carbon fiber frame and coaxially sleeved with the rolling protective roller. The rolling protective roller is rotatably connected to the carbon fiber frame through the self-lubricating bushing.

[0011] Furthermore, the airborne control unit includes a control unit housing, a satellite positioning module, a flight control and drive integrated module, and a battery; the satellite positioning module is horizontally installed on the top layer inside the control unit housing; the flight control and drive integrated module is installed directly below the satellite positioning module; the battery is installed on the bottom layer of the control unit housing, and the center of gravity of the battery is located on the vertical central axis of the UAV; and fixing brackets are respectively provided on both sides of the bottom of the control unit housing.

[0012] Furthermore, both the top and bottom panels of the control unit housing of the airborne control unit have machined holes.

[0013] Furthermore, the railcar body includes a telescopic frame with an adjustable chassis structure, the telescopic frame including multiple telescopic rods; multiple rail wheels are installed at both ends of the telescopic frame, and a hub motor is installed in each rail wheel, the hub motor being coaxially arranged with the rail wheel and driving the rail wheel to roll.

[0014] Furthermore, the railcar body is also equipped with a control unit and a cable retraction mechanism; the control unit is electrically connected to the hub motor, and the cable outlet of the cable retraction mechanism is vertically aligned with the tethering hole on the top of the telescopic frame, for real-time retraction and deployment of the tethering cable according to the flight altitude of the UAV; one end of the tethering cable is connected to the cable retraction mechanism, and the other end is connected to the control unit housing of the airborne control unit.

[0015] Furthermore, the nest includes a base and an inclined enclosure disposed on top of the base, and weight-reducing holes are provided on the four side walls of the enclosure.

[0016] Furthermore, the enclosure is provided with a guide section inside, the inner wall of which is an inclined conical structure that narrows from top to bottom; a limiting platform is provided at the center of the guide section, the limiting platform and the base are fixedly connected, and a through hole for tethering cables to pass through is provided at the center of the limiting platform along the vertical direction.

[0017] The present invention has the following beneficial technical effects:

[0018] This invention establishes an energy transmission link between a ground-based track chassis and an aerial drone via a tethered cable. The track vehicle, acting as a high-capacity power source, continuously supplies power to the drone, completely resolving the insufficient endurance problem caused by battery capacity limitations in multi-rotor drones during deep tunnel inspection missions. This extends the coverage area of ​​a single operation, overcomes the energy endurance bottleneck, and enables long-term operation.

[0019] This invention utilizes a track vehicle with precisely known coordinates, running along a fixed track, as a spatial pose reference source. Through cable tension feedback and a communication link, it corrects the dead reckoning drift of UAVs in real time in GPS / GNSS no-fly zones with no signal in tunnels, achieving centimeter-level air-to-ground coordinated accuracy, ensuring the spatial consistency of inspection data, establishing a high-precision pose reference, and solving the problem of positioning drift.

[0020] This invention employs a retractable frame and a chassis design with built-in hub motors, enabling it to adapt autonomously to subway lines with different track gauges. Simultaneously, both the onboard control unit and the engine compartment utilize numerous lightweight, perforated designs and vertical heat dissipation channels, reducing system power consumption while ensuring the operational reliability of core components in the enclosed, high-heat environment of tunnels. The design boasts high structural integration and strong environmental adaptability.

[0021] The drone frame and housing of this invention are mainly composed of carbon fiber sheets, 3D printed structural parts, and standard self-lubricating components. This reduces processing complexity, shortens the R&D and testing cycle, facilitates rapid modular assembly and disassembly and spare parts replacement at subway operation and maintenance sites, significantly reduces the system's lifecycle maintenance costs, and features a simple manufacturing process and easy modular maintenance. Attached Figure Description

[0022] Figure 1 This is a structural schematic diagram of the air-ground collaborative tethered inspection robot for subway tunnels according to the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the air-to-ground dual-mode UAV of the present invention;

[0024] Figure 3 This is a perspective view of the airborne control unit of the dual-mode UAV of the present invention;

[0025] Figure 4This is a structural schematic diagram of the bottom frame of the dual-track inspection vehicle of the present invention in a stretched state;

[0026] Figure 5 This is a schematic diagram of the structure of the bottom frame of the dual-track inspection vehicle of the present invention in its retracted state;

[0027] Figure 6 This is a schematic diagram of the tethered state of the air-ground collaborative tethered inspection robot for subway tunnels according to the present invention;

[0028] Figure 7 This is a schematic diagram of the structure of the dual-track inspection vehicle's housing in this invention;

[0029] In the diagram: 1. Dual-mode air-to-ground UAV; 11. Rolling protective roller; 12. Carbon rod clamp; 13. Carbon fiber frame; 14. Motor mounting plate; 15. Airborne control unit; 151. Satellite positioning module; 152. Flight control and drive integrated module; 153. Battery; 154. Mounting bracket; 16. Brushless motor; 17. Self-lubricating bushing; 18. Propeller blades;

[0030] 2. Nest; 21. Base; 22. Enclosure; 23. Weight reduction hole; 24. Guide section; 25. Limiting platform;

[0031] 3. Railcar body; 31. Tie-in hole; 32. Hub motor; 33. Rail wheel; 34. Control unit; 35. Telescopic frame; 41. Tie-in cable. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0033] Specific implementation method one: Combining Figures 1 to 7 This embodiment describes an air-ground collaborative tethered inspection robot for subway tunnels, comprising an air-ground dual-mode UAV 1, a nest 2, and a railcar body 3. The nest 2 is mounted on the top of the railcar body 3, and the air-ground dual-mode UAV 1 is housed inside the nest 2. The railcar body 3 and the air-ground dual-mode UAV 1 perform air-ground collaborative operations according to a preset inspection path. During the air-ground collaborative inspection of the subway tunnel, the air-ground dual-mode UAV 1 takes off from the nest 2, and the air-ground dual-mode UAV 1 and the railcar body 3 are connected by a tethered cable 41.

[0034] In a preferred embodiment, the air-to-ground dual-mode UAV 1 includes an airborne control unit 15, a carbon fiber frame 13, and a power assembly installed at the center of the UAV; the carbon fiber frame 13 is symmetrically arranged on both sides of the airborne control unit 15; the power assembly is installed at the far end of the middle of the carbon fiber frame 13; the brushless motor 16 of the power assembly is connected to both ends of the motor mounting plate 14 away from the carbon fiber frame 13, and the motor mounting plate 14 and the carbon fiber frame 13 are arranged perpendicularly, that is, the brushless motor 16 of the power assembly is installed at the far end of the carbon fiber frame 13.

[0035] In a preferred embodiment, the power assembly includes a motor mounting plate 14, a brushless motor 16 vertically connected to both ends of the motor mounting plate 14, and a blade 18 connected to the motor output shaft; the motor mounting plate 14 is connected to the carbon fiber frame 13 via a carbon rod clamp 12, and the motor mounting plate 14 and the carbon fiber frame 13 are arranged vertically.

[0036] In a preferred embodiment, the air-to-ground dual-mode UAV 1 further includes a rolling protective roller 11 and a self-lubricating bushing 17. The rolling protective roller 11 includes two sets of roller-type cage-like structures with honeycomb-shaped weight-reducing holes. The self-lubricating bushing 17 is symmetrically installed at both ends of the carbon fiber frame 13 and coaxially sleeved with the rolling protective roller 11. The rolling protective roller 11 is rotatably connected to the carbon fiber frame 13 through the self-lubricating bushing 17.

[0037] In a preferred embodiment, the airborne control unit 15 includes a control unit housing, a satellite positioning module 151, a flight control and drive integration module 152, and a battery 153; the satellite positioning module 151 is horizontally mounted on the uppermost layer inside the control unit housing; the flight control and drive integration module 152 is mounted directly below the satellite positioning module 151; the battery 153 is mounted on the bottom layer of the control unit housing, and the center of gravity of the battery 153 is located on the vertical central axis of the UAV; and mounting brackets 154 are respectively provided on both sides of the bottom of the control unit housing.

[0038] In a preferred embodiment, both the top and bottom panels of the control unit housing of the airborne control unit 15 have machined holes.

[0039] In a preferred embodiment, the railcar body 3 includes a telescopic frame 35 with an adjustable chassis structure, the telescopic frame 35 including multiple telescopic rods; multiple rail wheels 33 are installed at both ends of the telescopic frame 35, and a hub motor 32 is installed in each rail wheel 33. The hub motor 32 is coaxially arranged with the rail wheel 33 and drives the rail wheel 33 to roll.

[0040] In a preferred embodiment, the railcar body 3 is further provided with a control unit 34 and a cable retraction mechanism; the control unit 34 is electrically connected to the hub motor 32, and the cable outlet of the cable retraction mechanism is vertically aligned with the tethering hole 31 on the top of the telescopic frame 35, for real-time retraction and extension of the tethering cable 41 according to the flight altitude of the UAV; one end of the tethering cable 41 is connected to the cable retraction mechanism, and the other end is connected to the control unit housing of the airborne control unit 15.

[0041] In a preferred embodiment, the nest 2 includes a base 21 and an inclined enclosure 22 disposed on the top of the base, wherein weight-reducing holes 23 are provided on the four sides of the enclosure 22.

[0042] In a preferred embodiment, the enclosure 22 has a guide section 24 inside, the inner wall of which is an inclined conical structure that narrows from top to bottom; a limiting platform 25 is provided at the center of the guide section 24, the limiting platform 25 is fixedly connected to the base 21, and a through hole for the tethering cable 41 to pass through is provided at the center of the limiting platform 25 along the vertical direction. When the air-to-ground dual-mode UAV 1 is stored inside the nest 2, the two fixing brackets 154 at the bottom of the control unit housing are set on both sides of the limiting platform 25, the bottom surface of the control unit housing rests on the top surface of the limiting platform 25, keeping the air-to-ground dual-mode UAV 1 balanced, the rolling protective roller 11 contacts the base 21, and the enclosure 22 protects the air-to-ground dual-mode UAV 1.

[0043] Specific Implementation Method Two: Combining Figures 1 to 7 This embodiment describes an air-ground collaborative tethered inspection robot for subway tunnels, comprising a dual-track inspection vehicle and an air-ground dual-mode drone 1. The dual-track inspection vehicle includes a track vehicle body 3, track wheels 33 mounted below the track vehicle body 3, and a drone housing 2 fixed above the track vehicle body 3. The air-ground dual-mode drone 1 is normally stored in the drone housing 2 and takes off from the drone housing 2 during operation. One end of a tether cable 41 is connected to a cable retraction mechanism inside the dual-track inspection vehicle, and the other end passes through a tether hole 31 on the top of the track vehicle body 3 and is electrically connected to the air-ground dual-mode drone 1. The dual-track inspection vehicle transmits electrical energy to the air-ground dual-mode drone 1 through the tether cable 41, and the dual-track inspection vehicle and the air-ground dual-mode drone 1 perform air-ground collaborative operations according to a preset inspection path.

[0044] In a preferred embodiment, the air-to-ground dual-mode UAV 1 includes: an onboard control unit 15, located at the center of the UAV and serving as the core load-bearing component; a carbon fiber frame 13, which is radially and symmetrically fixed to the circumferential sidewalls of the onboard control unit 15 by carbon rod clamps 12; and a power assembly, installed at the far end of the carbon fiber frame 13, including a motor mounting plate 14, a brushless motor 16 vertically fixed to the mounting plate, and propellers 18 connected to the motor output shaft.

[0045] In a preferred embodiment, the air-to-ground dual-mode UAV 1 further includes: a rolling protective roller 11, which is a roller-type cage structure with two sets of honeycomb-shaped weight-reducing holes; and a self-lubricating bushing 17, which is symmetrically installed on the periphery of the brushless motor 16 or the motor fixing plate 14 and coaxially sleeved with the rolling protective roller 11, wherein the rolling protective roller 11 can rotate freely around the self-lubricating bushing 17.

[0046] In a preferred embodiment, the internal circuit of the airborne control unit 15 adopts a three-layer vertical stacked layout: a satellite positioning module 21, which is horizontally installed on the top layer of the internal cavity; a flight control and drive integration module 22, which is suspended and installed directly below the satellite positioning module 21 via a shock-absorbing bracket; and a battery 23, which is placed at the bottom layer of the cavity to provide power compensation in an emergency when the tethered cable 41 is de-energized.

[0047] In a preferred embodiment, both the top and bottom panels of the airborne control unit 15 have machined holes. These machined holes serve two purposes: firstly, to reduce the overall mass of the air-to-ground dual-mode UAV 1 by removing material; and secondly, to form a vertical heat dissipation channel running vertically through the cavity, utilizing the downdraft generated by the rotor to assist in the heat dissipation of the internal electronic components.

[0048] In a preferred embodiment, the dual-rail inspection vehicle has an adjustable chassis structure: a telescopic frame 35 is connected below the railcar body 3, and the telescopic frame 35 includes multi-stage telescopic rods for adjusting the distance between the two side rail wheels 33 in real time according to the track gauge of the subway track; each set of rail wheels 33 is embedded with a hub motor 32, which directly drives the rail wheels to roll on the track, thereby realizing high-precision displacement control of the dual-rail inspection vehicle.

[0049] In a preferred embodiment, the railcar body 3 is further provided with: a control unit 34, which is electrically connected to the hub motor 32 and is responsible for the motion control logic of the whole vehicle; and a cable retraction mechanism, the outlet of which is vertically aligned with the mooring hole 31, for retracting and extending the mooring cable 41 in real time according to the flight altitude of the UAV.

[0050] In a preferred embodiment, the nest 2 is designed with guiding and lightweight features: a hollowed-out sidewall structure is arrayed on the inclined sidewall of the nest 2; the hollowed-out sidewall structure is used to reduce the overall mass of the nest 2, realizing the lightweight design of the robot; a guiding slope is set on the top of the nest 2, the inner diameter of which gradually narrows from the opening towards the base; the guiding slope is used to guide the central axis of the drone to automatically align with the central axis of the nest 2 through mechanical limiting during the landing and recovery process of the air-to-ground dual-mode drone 1, thereby achieving precise reset.

[0051] In this embodiment, the cable retraction mechanism of the tether cable 41 and the multi-stage telescopic rods included in the telescopic frame 35 of the railcar body 3 are both based on existing technologies. They can realize the retraction of the tether cable 41 and the axial width adjustment of the track wheel 33 of the telescopic frame 35. They use general standard parts or components known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals.

[0052] The other components and connections are the same as in Specific Implementation Method 1.

[0053] Specific implementation method three: Combining Figures 1 to 7 This embodiment describes an air-ground collaborative tethered inspection robot for subway tunnels, comprising a dual-track inspection vehicle and an air-ground dual-mode drone 1. The dual-track inspection vehicle includes a track vehicle body 3, track wheels 33 mounted below the track vehicle body 3, and a housing 2 fixed above the track vehicle body 3. The air-ground dual-mode drone 1 is normally stored in the housing 2 and takes off from the housing 2 during operation. One end of a tether cable 41 is connected to a cable retraction mechanism inside the dual-track inspection vehicle, and the other end passes through a tether hole 31 on the top of the track vehicle body 3 and is electrically connected to the air-ground dual-mode drone 1. The dual-track inspection vehicle transmits electrical energy to the air-ground dual-mode drone 1 through the tether cable 41, and the dual-track inspection vehicle and the air-ground dual-mode drone 1 perform air-ground collaborative operations according to a preset inspection path.

[0054] In a preferred embodiment, the air-to-ground dual-mode UAV 1 includes an onboard control unit 15 located at the center of the UAV as a core load-bearing component; a carbon fiber frame 13, which is radially and symmetrically fixed to the circumferential sidewall of the onboard control unit 15 by carbon rod clamps 12; and a power assembly installed at the far end of the carbon fiber frame 13, including a motor mounting plate 14, a brushless motor 16 vertically fixed to the mounting plate, and propellers 18 connected to the motor output shaft.

[0055] In a preferred embodiment, the air-to-ground dual-mode UAV 1 further includes a rolling protective roller 11, which is a roller-type cage structure with two sets of honeycomb-shaped weight-reducing holes; and a self-lubricating bushing 17, which is symmetrically installed on the periphery of the brushless motor 16 or the motor fixing plate 14 and coaxially sleeved with the rolling protective roller 11.

[0056] The axial length of the rolling protective roller 11 is greater than the height of the rotation plane of the blade 18, and the rolling protective roller 11 can rotate freely around the self-lubricating bushing 17.

[0057] In a preferred embodiment, the internal circuit of the airborne control unit 15 adopts a three-layer vertical stacked layout: the satellite positioning module 21 is horizontally installed on the top layer of the internal cavity; the flight control and drive integration module 22 is suspended and installed directly below the satellite positioning module 21 by a shock-absorbing bracket; and the battery 23 is installed on the bottom layer of the cavity by a fixing slot, with its center of gravity located on the vertical central axis of the UAV.

[0058] In a preferred embodiment, both the top and bottom panels of the airborne control unit 15 have machined holes.

[0059] In a preferred embodiment, the dual-rail inspection vehicle has an adjustable chassis structure: a telescopic frame 35 is connected below the railcar body 3, the telescopic frame 35 includes multiple telescopic rods, and a hub motor 32 is embedded in each set of rail wheels 33. The hub motor 32 is coaxially arranged with the rail wheels 33 and directly drives them to roll.

[0060] In a preferred embodiment, the railcar body 3 is further provided with: a control unit 34, which is electrically connected to the hub motor 32 and is responsible for the motion control logic of the whole vehicle; and a cable retraction mechanism, the outlet of which is vertically aligned with the mooring hole 31, for retracting and extending the mooring cable 41 in real time according to the flight altitude of the UAV.

[0061] In a preferred embodiment, the nest 2 includes a base and an inclined protective sidewall, the sidewall having an array of perforated weight-reducing holes; the top has a funnel-shaped guide portion, the inner wall of which is tapered and inclined from top to bottom, and the lowest point of the funnel-shaped guide portion is aligned with the mooring hole 31 in the vertical direction.

[0062] The other components and connections are the same as in Specific Implementation Method 1.

[0063] Specific implementation method four: Combination Figures 1 to 7 This embodiment describes an air-ground collaborative tethered inspection robot for subway tunnels. Addressing the challenges of limited space, GPS shielding, and extremely high inspection accuracy requirements in subway tunnels, this system solves the problems of insufficient battery life, positioning drift, and large blind spots in existing equipment by constructing a deep collaborative mode between a dual-track inspection vehicle and a tethered drone.

[0064] The air-ground collaborative tethered inspection robot system for subway tunnels includes a heavy-duty dual-rail inspection vehicle, a tethered drone with a protective structure, and a collaborative control system. The dual-rail inspection vehicle serves as a mobile energy station and a high-precision positioning reference, providing continuous power to the drone via a tethered cable; the drone utilizes the absolute geographic coordinates of the rail vehicle to achieve follow-up navigation and spatial pose compensation.

[0065] This invention combines the long-term operational capabilities of ground equipment with the high accessibility of aerial platforms, supporting continuous system inspections for over two hours. Through simultaneous acquisition of multi-dimensional data from both air and ground, and real-time edge processing, it achieves high-precision, comprehensive intelligent detection of tunnel intrusions, lining cracks, and the status of electromechanical equipment. This invention significantly improves inspection efficiency and real-time alarm performance in enclosed and complex environments, demonstrating significant engineering application potential.

[0066] In this embodiment, in response to the problems of short endurance, poor spatial positioning accuracy and high risk of collision in confined spaces of existing subway tunnel inspection drones, the purpose of this invention is to provide an air-ground collaborative tethered inspection robot system for subway tunnels, including an air-ground dual-mode drone 1, a drone nest 2, a railcar body 3 and a tethered cable 41.

[0067] Figure 1 shows a schematic diagram of the structure of the air-ground collaborative tethered inspection robot for subway tunnels in tethered inspection mode. The system establishes air-ground coupling through tethered cable 41 to realize continuous power supply and physical posture constraint of the air platform by the ground chassis.

[0068] Figure 2 shows the structural composition of the air-to-ground dual-mode UAV 1 of the present invention.

[0069] In Figure 2, 11 is a rolling protective roller made of carbon fiber. This roller utilizes the high hardness and lightweight properties of carbon fiber to protect internal components when it comes into contact with the tunnel wall.

[0070] In Figure 2, 12 is a carbon rod clamp, which is made of iron. Because iron has excellent fatigue strength, it can ensure that the outrigger does not become physically loose under long-term, high-frequency vibration, thus maintaining the consistency of flight attitude.

[0071] In Figure 2, 13 represents the carbon fiber frame, which is 2.0 mm thick. High-modulus carbon fiber plates are used as the main support to provide the UAV with extremely high structural rigidity to withstand the downward force of the tethered cable.

[0072] In Figure 2, 14 is the motor mounting plate, which is made of carbon fiber and has a thickness of 3.0 mm. The four-axis symmetrical layout improves the balance of power output.

[0073] In Figure 2, 16 is a brushless motor, model 1507. This motor has a high thrust-to-weight ratio and, when combined with 4-inch blades (18), can provide precise lift response in the turbulent environment of a confined tunnel.

[0074] In Figure 2, 17 is a self-lubricating bushing, which is fitted around the outer circumference of the motor base and cooperates with the protective roller 11 to achieve physical decoupling between the protective structure and the rotational power system, so that the roller can rotate independently and freely when it comes into contact with an obstacle.

[0075] Figure 3 shows an internal perspective view of the airborne control unit 15 of the air-to-ground dual-mode UAV of the present invention.

[0076] Figure 3 shows the airborne control unit housing (15), which is manufactured using 3D printing technology. Its top and bottom panels have machined ventilation holes, utilizing the downwash airflow generated by the rotor to create a vertical cooling flow field.

[0077] In Figure 3, 151 is the satellite positioning module, which is horizontally installed on the top layer of the internal cavity.

[0078] In Figure 3, 152 is the flight control and drive integrated module, which is suspended and mounted through a rubber shock-absorbing bracket to effectively isolate the high-frequency resonance generated by the 1507 motor and ensure the accuracy of sensor data.

[0079] In Figure 3, 153 is the battery, which has a specification of 4S and 2000mAh. It is placed at the bottom of the cavity to lower the center of gravity.

[0080] Figure 4 shows a schematic diagram of the dual-track inspection vehicle base and telescopic mechanism of the present invention.

[0081] In Figure 4, 35 represents the telescopic frame, constructed primarily of industrial aluminum profiles conforming to European Standard 2020. The T-slot structure of the aluminum profiles facilitates span adjustment, thus adapting to the track gauge requirements of different subway lines.

[0082] In Figure 4, 33 represents the track wheel, which houses a high-power hub motor 32. The hub motor directly drives the track wheel and provides the system with millimeter-level displacement data by acquiring encoder feedback.

[0083] In Figure 4, 3 represents the railcar body, which integrates the control unit 34 and the cable retraction mechanism, responsible for the motion control of the entire vehicle and the cable tension management.

[0084] Figure 5 shows the structure of the nest 2 of the present invention.

[0085] In Figure 5, 2 represents the drone's nest, which is 3D printed using high-performance materials. Its top features a funnel-shaped guide ramp with an angle set between 10° and 20° to ensure automatic center alignment during drone recovery.

[0086] Figure 6 shows the interaction structure of the mooring cable 41 and the mooring hole 31.

[0087] In Figure 6, 41 is a tethered cable, which contains a high-purity copper core and has continuous current carrying capacity.

[0088] In Figure 6, 31 is a mooring hole, located on the geometric center axis of the railcar body. The edge is equipped with a self-lubricating bushing to reduce mechanical wear during cable winding and unwinding.

[0089] The other components and connections are the same as in Specific Implementation Method 1.

[0090] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A ground-to-air collaborative tethered inspection robot for subway tunnels, characterized in that: It includes an air-to-ground dual-mode UAV (1), a nest (2), and a railcar body (3); the nest (2) is installed on the top of the railcar body (3), and the air-to-ground dual-mode UAV (1) is located inside the nest (2); The railcar body (3) and the air-ground dual-mode UAV (1) perform air-ground coordinated operation according to the preset inspection path. When the subway tunnel air-ground coordinated inspection is carried out, the air-ground dual-mode UAV (1) takes off from the nest (2), and the air-ground dual-mode UAV (1) and the railcar body (3) are connected by a tethered cable (41).

2. The air-ground collaborative tethered inspection robot for subway tunnels according to claim 1, characterized in that: The air-to-ground dual-mode UAV (1) includes an airborne control unit (15), a carbon fiber frame (13), and a power assembly installed at the center of the UAV; the carbon fiber frame (13) is symmetrically arranged on both sides of the airborne control unit (15); the power assembly is installed at the far end of the middle of the carbon fiber frame (13).

3. The air-ground collaborative tethered inspection robot for subway tunnels according to claim 2, characterized in that: The power assembly includes a motor mounting plate (14), a brushless motor (16) vertically connected to both ends of the motor mounting plate (14), and a blade (18) connected to the motor output shaft. The motor mounting plate (14) is connected to the carbon fiber frame (13) via a carbon rod clamp (12), and the motor mounting plate (14) and the carbon fiber frame (13) are vertically arranged.

4. The air-ground cooperative tethered inspection robot for subway tunnels according to claim 1, characterized in that: The air-ground dual-mode UAV (1) also includes a rolling protective roller (11) and a self-lubricating bushing (17). The rolling protective roller (11) includes two sets of roller-type cage structures with honeycomb-shaped weight-reducing holes. The self-lubricating bushing (17) is symmetrically installed at both ends of the carbon fiber frame (13) and coaxially connected with the rolling protective roller (11); the rolling protective roller (11) is rotatably connected to the carbon fiber frame (13) through the self-lubricating bushing (17).

5. The air-ground collaborative tethered inspection robot for subway tunnels according to claim 2, characterized in that: The airborne control unit (15) includes a control unit housing, a satellite positioning module (151), a flight control and drive integration module (152), and a battery (153). The satellite positioning module (151) is horizontally installed on the top layer inside the control unit housing; the flight control and drive integration module (152) is installed directly below the satellite positioning module (151); the battery (153) is installed on the bottom layer of the control unit housing, and the center of gravity of the battery (153) is located on the vertical central axis of the UAV; the bottom two sides of the control unit housing are respectively provided with fixing brackets (154).

6. The air-ground cooperative tethered inspection robot for subway tunnels according to claim 5, characterized in that: The top and bottom panels of the airborne control unit (15) housing have machined holes.

7. The air-ground cooperative tethered inspection robot for subway tunnels according to claim 1, characterized in that: The railcar body (3) includes a telescopic frame (35) with an adjustable chassis structure, and the telescopic frame (35) includes multi-stage telescopic rods; Multiple track wheels (33) are installed at both ends of the telescopic frame (35). Each track wheel (33) is equipped with a hub motor (32). The hub motor (32) is coaxial with the track wheel (33) and drives the track wheel (33) to roll.

8. The air-ground collaborative tethered inspection robot for subway tunnels according to claim 1, characterized in that: The railcar body (3) is also equipped with a control unit (34) and a cable retraction mechanism; the control unit (34) is electrically connected to the hub motor (32), and the cable outlet of the cable retraction mechanism is vertically aligned with the tethering hole (31) on the top of the telescopic frame (35) for real-time retraction and deployment of the tethering cable (41) according to the flight altitude of the UAV; one end of the tethering cable (41) is connected to the cable retraction mechanism, and the other end is connected to the control unit housing of the airborne control unit (15).

9. The air-ground collaborative tethered inspection robot for subway tunnels according to claim 1, characterized in that: The nest (2) includes a base (21) and an inclined enclosure (22) set on the top of the base. Weight reduction holes (23) are provided on the four sides of the enclosure (22).

10. The air-ground cooperative tethered inspection robot for subway tunnels according to claim 9, characterized in that: The enclosure (22) is provided with a guide (24) inside, and the inner wall of the guide (24) is an inclined conical structure that narrows from top to bottom; The guide section (24) has a limiting platform (25) at its internal center. The limiting platform (25) and the base (21) are fixedly connected. The center of the limiting platform (25) has a through hole along the vertical direction for the tethering cable (41) to pass through.

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