Rail type subway tunnel intelligent inspection robot and use method thereof

Abstract

The application discloses a track type subway tunnel intelligent inspection robot and a use method thereof. The robot comprises a walking chassis, a main control box, a lifting device, a horizontal displacement mechanism, a mechanical arm and a detection module. The main control box and the lifting device are arranged on the walking chassis, the horizontal displacement mechanism is arranged on the lifting device, the mechanical arm is arranged on the horizontal displacement mechanism, and the detection module is installed on the mechanical arm. The walking chassis travels along a track, the lifting device and the horizontal displacement mechanism drive the mechanical arm to adjust the position, and the detection module adjusts the microscopic three-dimensional posture. The use method comprises a self-checking preparation stage, an addressing and self-adaptive cruise stage, a dynamic obstacle avoidance operation, a surface-adhesion blind area-free multi-source data acquisition, edge screening, data return and reset clearing. The application effectively avoids the shielding of complex pipelines and catenary systems on the top of a tunnel, and realizes the dead-angle-free, close-range surface-adhesion high-precision automatic exploration of defects on the tunnel roof.

Description

Technical Field

[0001] This invention belongs to the field of subway tunnel inspection technology, and relates to an intelligent inspection robot that uses a robotic arm to detect defects in the roof of a subway tunnel from multiple angles. Background Technology

[0002] With the rapid development of urban rail transit, the safe operation of subway tunnels has received increasing attention. During the long-term service of subway tunnels, factors such as geological subsidence, groundwater erosion, and train vibration can easily lead to structural defects in tunnel segments, such as cracks, spalling, and water leakage. Among these, defects in the tunnel roof area are directly above the train and the overhead contact line. Once a piece falls off or there is severe leakage, it can easily cause major train safety accidents such as power outages and service stoppages. Therefore, daily inspection of the tunnel roof is crucial.

[0003] Currently, the inspection of subway tunnel roof slabs mainly relies on manual nighttime foot patrols using existing technology. However, this method has the following significant drawbacks: Limited visibility and low accuracy: The tunnel roof slab is quite high above the track surface (usually more than 4-5 meters). When manually observing from below with a flashlight or binoculars in the track area, it is difficult to see tiny cracks in the roof slab (such as cracks smaller than 0.2mm). This is easily affected by subjective experience and eye fatigue, leading to a high rate of missed inspections. Low work efficiency and safety hazards: Subway lighting is poor at night, making manual foot patrols inefficient. If mobile scaffolding or ladder trucks are used to assist in high-altitude inspections, not only is the transportation cumbersome, but there is also a significant risk of personnel falling from heights.

[0004] To improve efficiency, the industry has introduced track-mounted tunnel inspection vehicles. However, traditional track-mounted inspection vehicles still face insurmountable technical bottlenecks when dealing with the specific requirement of "roof inspection": They suffer from severe blind spots: traditional inspection vehicles typically mount cameras in a fixed-angle array around the vehicle body in a ring layout. However, subway tunnel roofs are often densely packed with complex facilities such as rigid contact wires, lighting cables, and fire-fighting pipelines. The fixed camera angle is easily obstructed by these pipelines, making it impossible to directly observe the true condition of the roof behind the pipelines, creating large-area inspection blind spots. There is also a conflict between focal length and resolution, lacking flexible close-up capabilities: because the cameras are fixed to the vehicle body and far from the roof, even with high-magnification lenses, it is difficult to obtain high-precision microscopic textures. Traditional equipment lacks the ability to flexibly adjust its spatial orientation, making it impossible to extend into the gaps between pipelines for close-up, high-definition inspection.

[0005] In summary, existing inspection methods and fixed track inspection equipment cannot simultaneously guarantee safety and efficiency, and are difficult to achieve high-definition, blind-spot-free inspection of the tunnel roof under the obstruction of complex pipelines. Therefore, there is an urgent need for an automated inspection device that can flexibly avoid overhead obstacles and achieve multi-angle, close-range inspection. Summary of the Invention

[0006] To address the shortcomings of existing tunnel inspection technologies, such as low efficiency and high risks associated with manual roof inspections, as well as the limitations of traditional fixed-track inspection vehicles due to blind spots caused by overhead contact lines and pipelines, and the inability to perform close-range inspections, this invention provides a track-mounted intelligent inspection robot for subway tunnels. This robot is designed to flexibly avoid complex obstacles on the tunnel roof and achieve blind-spot-free, close-range, and high-precision automatic inspection of roof defects.

[0007] To achieve the above objectives, the rail-mounted intelligent inspection robot for subway tunnels of the present invention adopts the following technical solution.

[0008] The inspection robot includes a walking chassis, a main control box, a lifting device, a horizontal displacement mechanism, a robotic arm, and an inspection module.

[0009] The traveling chassis includes a chassis frame and a drive mechanism mounted on the chassis frame, with an encoder in the drive mechanism; the chassis frame is used to carry the main control box and lifting device and moves along the subway tunnel track;

[0010] Main control box: This includes a box mounted on a chassis frame. Inside the box is a main control computer and a communication module. The box is equipped with a display screen, a camera, and an obstacle detection radar. The communication module, display screen, camera, and obstacle detection radar are all connected to the main control computer, which in turn connects to a cloud server via the communication module. In addition, the display screen, camera, obstacle detection radar, communication module, and main control computer are all connected to a power supply unit located inside the box. The power supply unit is electrically connected to the energy storage battery pack.

[0011] Lifting device: Fixedly installed on the chassis frame or main control box, used to drive the horizontal displacement mechanism, robotic arm and detection module to lift and lower, so as to realize the one-dimensional linear translational motion of the detection module;

[0012] Horizontal displacement mechanism: mounted on the lifting device, used to drive the robotic arm and detection module to move horizontally;

[0013] Robotic arm: Mounted on the horizontal displacement mechanism, it moves in translating motion with the horizontal displacement mechanism and is used to perform multi-dimensional spatial posture adjustments for the detection module;

[0014] The detection module includes a CCD camera and a laser contour scanner, which are mounted on a robotic arm and connected to the main control computer. It is used to acquire images and depth data of the tunnel roof.

[0015] The electric components in the walking chassis, lifting device, horizontal displacement mechanism, and robotic arm are all connected to the main control computer in the main control box.

[0016] Further, as described below.

[0017] The drive mechanism of the chassis includes an active walking mechanism and a driven walking mechanism mounted on the chassis frame. The active walking mechanism includes a drive wheel mounting bracket at the bottom of the chassis frame, and a drive motor and a reducer mounted on the drive wheel mounting bracket. The active end of the reducer is connected to the shaft of the drive motor, and the drive wheel is mounted on the power output end of the reducer. The driven walking mechanism includes a driven wheel mounting bracket at the bottom of the chassis frame, and a driven wheel mounted on the driven wheel mounting bracket. The drive motor is a servo motor with an absolute encoder and a built-in power-off braking mechanism. Both the absolute encoder and the servo motor are connected to the main control computer. The driven wheel is elastically mounted on the driven wheel mounting bracket via a shock-absorbing module. The main control computer controls the operation of the drive motor, which drives the drive wheel to rotate, moving the entire chassis on the subway track. The encoder inside the motor provides feedback for real-time mileage calculation, achieving centimeter-level precise parking positioning within the tunnel.

[0018] The main control box is connected to a base, which is fixedly mounted on the chassis frame of the walking chassis. The side of the box has an inverted V-shaped groove to accommodate the installation space for the energy storage battery pack and other related components. A driving light is installed on the side of the box, and an audible and visual warning light is installed on the top of the box. Both the driving light and the audible and visual warning light are electrically connected to the power supply unit located inside the box.

[0019] The lifting device includes two lifting mechanisms, which are synchronously driven by a main control computer. The main control computer employs a cross-coupled PID synchronous control algorithm. Specifically, the main control computer acquires the displacement feedback values ​​y1 and y2 of the lifting ends in the two lifting mechanisms in real time. Given a synchronous target displacement γ, it calculates the displacement tracking errors e1 = γ - y1 and e2 = γ - y2, and simultaneously calculates the synchronous error ɛ = y1 - y2. The main control computer combines the PID adjustment of the displacement tracking errors e1 and e2 with compensation for the synchronous error ɛ to calculate the target speeds U1 and U2 of the drive motors in the two lifting mechanisms: U1 = PID(e1) - K·ɛ, U2 = PID(e2) + K·ɛ, where K is the synchronous compensation gain coefficient. This algorithm eliminates the displacement difference between the two lifting mechanisms caused by uneven mechanical load in real time, achieving strictly equal displacement lifting.

[0020] The horizontal displacement mechanism includes a horizontal slide table and a robotic arm mounting base. The horizontal slide table is fixedly connected to the lifting device, and the robotic arm mounting base is fixedly mounted on the horizontal slide table via a slider connector. Two segmented sleeve lifting mechanisms in the lifting device operate synchronously, driving the horizontal slide table to rise and fall as a whole. The horizontal slide table employs a screw-nut pair moving mechanism, internally integrating a high-precision guide rail and a screw transmission pair. The robotic arm mounting base is equipped with a robotic arm positioning block and a robotic arm positioning pin for mounting and fixing the robotic arm.

[0021] The robotic arm is a multi-degree-of-freedom robotic arm, employing a six-axis flexible collaborative design with multiple rotary joints for multi-dimensional spatial attitude adjustment. The multi-degree-of-freedom robotic arm is positioned and mounted on a horizontal displacement mechanism via robotic arm positioning blocks and positioning pins.

[0022] The detection module includes a quick-connect flange, a mounting bracket, and a detection box. The detection box is fixedly mounted on the mounting bracket, which is equipped with a quick-connect flange. The quick-connect flange connects to the end of the robotic arm. The detection box contains the CCD camera and a laser contour scanner. An array of strobe lights is installed around the inner wall of the detection box to resist reflections from the tunnel wall and acquire shadow-free, high-contrast defect images and depth point cloud data.

[0023] The method of using the above-mentioned intelligent inspection robot for subway tunnels includes the following steps:

[0024] (1) Self-inspection preparation stage;

[0025] The walking chassis, lifting device, horizontal displacement mechanism and robotic arm are reset to the mechanical origin to establish a unified global coordinate system, and the CCD camera and laser contour scanner in the detection module are calibrated for reference white balance.

[0026] (2) Addressing and adaptive cruise phase;

[0027] The chassis receives the tunnel segment inspection task list from the main control computer and cruises along the subway tunnel track. During the cruise, cameras and obstacle detection radar monitor the surrounding environment in real time. If an emergency or obstacle is encountered, the chassis activates emergency power-off braking, and the main control computer records the abnormal information and reports it to the cloud server in a timely manner. If there are no abnormalities during the cruise, the main control computer calculates the mileage in real time and performs absolute coordinate correction based on the segment joint characteristics until it stops precisely under the target segment suspected of having a roof defect.

[0028] (3) Dynamic obstacle avoidance operation;

[0029] First, a coarse adjustment is performed. The main control computer raises the output end of the lifting device, sending the horizontal displacement mechanism, robotic arm, and detection module to the safety boundary below the pipeline. Second, the horizontal displacement mechanism moves horizontally to find the entry point. The horizontal displacement mechanism controls the robotic arm to move laterally, using the end vision of the robotic arm to find the optimal obstacle avoidance gap between the pipelines. Finally, the robotic arm is controlled to perform fine adjustment and insertion. After confirming the entry point, the robotic arm starts and delivers the end to the optimal focal length position (15-20 cm) from the top plate surface.

[0030] (4) No blind spots in surface-mounted multi-source data acquisition;

[0031] After the detection module reaches the designated surface pose, it begins to work; the laser profilometer emits structured light to extract the misalignment and crack depth of the top plate, and the CCD camera simultaneously performs high-frequency continuous shooting; with the assistance of the robotic arm, the push-broom panoramic image stitching of the local blind area is completed.

[0032] (5) Edge filtering, backhaul and reset clearing;

[0033] The data collected by the detection module is transmitted in real time to the main control computer in the main control box for pre-screening. After invalid frames are removed, the data is packaged and uploaded to the cloud server. Subsequently, the robotic arm, horizontal drive mechanism and lifting device are reset, and the chassis is released from braking.

[0034] In step (2), the process of the main control computer performing real-time mileage calculation is as follows: the main control computer reads the pulse data of the encoder of the chassis drive mechanism at fixed intervals. The diameter of the drive wheel in the chassis is D, and the rated number of pulses for one revolution of the encoder is P. The pulse increment read within the sampling period is The increase in mileage per cycle The main control computer continuously... Discrete integrals are accumulated, and combined with the initial starting coordinates, the absolute mileage coordinates of the chassis in the tunnel are calculated in real time.

[0035] The present invention has the following beneficial effects:

[0036] 1. Overcoming visual obstruction to achieve blind-spot-free surface detection:

[0037] This invention, by combining a "horizontal displacement mechanism" with a "multi-degree-of-freedom robotic arm," completely breaks the fixed-view limitation of traditional inspection vehicle cameras. The robotic arm can dexterously navigate around overhead contact lines and various pipelines, just like a human arm, and directly place a high-definition lens close to the tunnel roof surface for "face-to-face" imaging, successfully eliminating blind spots behind complex pipelines.

[0038] 2. Dynamically expand the working envelope to improve detection stability:

[0039] Traditional robotic arms often require extremely long reach to cover wide tunnel ceilings, leading to instability and end effector tremors. This invention adds a linear translation mechanism to the top of the main control box, allowing the robotic arm to perform secondary translations on the moving base. Without increasing the length of a single arm, this significantly expands the lateral and longitudinal detection coverage, ensuring extremely high image stability during macro photography.

[0040] 3. High precision and high automation enhance operational security:

[0041] This invention enables unmanned operation of tunnel roof inspection. It not only completely replaces the high-risk manual inspection at height, reducing the risk of safety accidents, but also uses high-precision sensors to capture tiny cracks at the millimeter level that are difficult for the human eye to see, greatly improving the data accuracy and maintenance efficiency of daily subway operations. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the overall structure of the track-mounted intelligent inspection robot for subway tunnels according to the present invention.

[0043] Figure 2 This is a schematic diagram of the working state of the track-mounted intelligent subway tunnel inspection robot of the present invention inside the tunnel;

[0044] Figure 3 This is a schematic diagram of the chassis structure in this invention;

[0045] Figure 4 This is a schematic diagram showing the positional relationship between the main control box and the chassis in this invention;

[0046] Figure 5 This is a schematic diagram showing the positional relationship between the main control box and the lifting device in this invention;

[0047] Figure 6 This is a schematic diagram showing the positional relationship between the lifting device, the horizontal displacement mechanism, and the multi-degree-of-freedom robotic arm in this invention;

[0048] Figure 7 This is a schematic diagram showing the positional relationship between the multi-degree-of-freedom robotic arm and the detection module in this invention;

[0049] Figure 8 This is a schematic diagram of the detection module in this invention.

[0050] In the diagram: 1. Walking chassis, 2. Main control box, 3. Lifting device, 4. Horizontal displacement mechanism, 5. Multi-degree-of-freedom robotic arm, 6. Detection module;

[0051] 11. Chassis frame; 12. Driven wheel mounting bracket; 13. Driven wheel; 14. Drive motor; 15. Drive wheel; 16. Motor suspension plate; 17. Drive wheel mounting bracket;

[0052] 21. Base, 22. Housing, 23. Driving lights, 24. Touch screen, 25. Environmental perception camera, 26. Obstacle detection radar, 27. Audible and visual warning lights;

[0053] 31. Segmented sleeve lifting mechanism; 32. Inclined fixed bracket; 33. Horizontal slide table mounting plate; 34. Horizontal slide table mounting clamp.

[0054] 41. Horizontal slide table; 42. Drive motor; 43. Robotic arm mounting base; 44. Robotic arm positioning block; 45. Robotic arm positioning pin;

[0055] 51. Robotic arm base; 52. Upper arm; 53. Forearm; 54. End joint;

[0056] 61. Quick-connect flange, 62. Mounting bracket, 63. Detection box, 64. Sensor window. Detailed Implementation

[0057] This invention relates to a track-mounted intelligent inspection robot for detecting defects in the roof slabs of subway tunnels. Unlike traditional single-dimensional inspection equipment, this invention employs a "macro-micro" composite motion architecture in its mechanical topology, such as... Figure 1 As shown, the system includes a walking chassis 1, a lifting device 3, a horizontal displacement mechanism 4, a multi-degree-of-freedom robotic arm 5, and a detection module 6. The walking chassis 1 and the lifting device 3 are mounted on the walking chassis 1, the horizontal displacement mechanism 4 is mounted on the lifting device 3, the multi-degree-of-freedom robotic arm 5 is mounted on the horizontal displacement mechanism 4, and the detection module 6 is mounted on the multi-degree-of-freedom robotic arm 5. A main control box 2 is also mounted on the walking chassis 1. From bottom to top, the system comprises: a system for macroscopic positioning (walking chassis 1), a system for vertical span adjustment (lifting device 3), a system for lateral obstacle crossing (horizontal displacement mechanism 4), and a system for microscopic flexible detection (robotic arm 5 and detection module 6). Under the unified scheduling of the main control computer within the main control box 2, each subsystem interacts with data via a high-speed industrial bus, forming a deeply coupled closed-loop feedback control network. Figure 2 The tooling status of the track-mounted intelligent subway tunnel inspection robot of the present invention in the tunnel is shown.

[0058] The mobile chassis 1 is mounted on the subway track, adapted to the standard subway gauge, and integrates a drive mechanism and a braking mechanism. It supports the entire robot system and moves longitudinally along the subway tunnel track. The mobile chassis 1 not only serves a load-bearing function but also functions as an absolute odometer for measuring distances within the tunnel. Its structure is as follows: Figure 3As shown, the system includes a chassis frame 11 and an active and a passive walking mechanism mounted on the chassis frame 11. The chassis frame 11 is welded from high-strength, lightweight alloy profiles. The passive walking mechanism includes passive wheel mounting brackets 12 bolted to the four corners of the bottom of the chassis frame 11, and passive wheels 13 elastically connected to the passive wheel mounting brackets 12 via connecting blocks and shock-absorbing modules. The active walking mechanism includes a drive wheel mounting bracket 17 mounted on the chassis frame 11, a drive motor 14 mounted on the drive wheel mounting bracket 17, and a reducer. The active end of the reducer is connected to the shaft of the drive motor 14, and the passive end (transmission flange) of the reducer mounts the drive wheel 15. The drive motor 14 is mounted on the drive wheel mounting bracket 17 via a motor suspension plate 16. Preferably, it is an AC servo motor with a high-precision absolute encoder, and the drive motor 14 has a built-in power-off braking mechanism. The encoder is connected to the main control computer in the main control box 2. The drive motor 14 drives the drive wheel 15 to rotate through the reducer, causing the entire chassis 1 to move on the subway track. The main control computer can calculate the mileage in real time through feedback from the encoder inside the motor. The calculation process is as follows: The main control computer reads the pulse data of the absolute encoder built into the drive motor 14 at fixed intervals. Let the diameter of the drive wheel 15 be D, and the rated number of pulses per revolution of the encoder be P. The pulse increment read within the sampling period is (The cumulative value of the pulse increment output by the encoder within the sampling period), then the mileage increment in a single period. The main control computer continuously... By performing discrete integral accumulation and combining it with the initial starting coordinates, the absolute mileage coordinates of the inspection robot (walking chassis 1) in the tunnel can be calculated in real time, thereby achieving centimeter-level precise parking.

[0059] The main control box 2 is fixedly installed on top of the walking chassis 1, such as... Figure 4As shown, the main control box 2 adopts a split structure design, including a base 21 and a housing 22 connected to the base 21. The base 21 is fixedly installed on the chassis frame 11 in the walking chassis 1, and the base 21 has reserved installation positions for the energy storage battery pack and various subsystem modules. The left and right sides of the housing 22 are provided with inverted V-shaped grooves. This design not only ensures sufficient installation space for the aforementioned energy storage battery pack and various subsystem modules, but also cleverly reserves positions for the reinforcement installation of the lifting devices 3 on both sides, and also reserves mechanical clearance space for vertical movement, avoiding movement interference. Furthermore, the split design of the main control box 2 allows for quick disassembly and inspection. A touch screen 24 is embedded in the front of the housing 22, providing a visual human-machine interface; a driving light 23 is located below the touch screen 24 on the housing 22. The top of the housing 22 integrates an environmental perception camera 25 (supporting 5G and tunnel private network communication), an obstacle detection radar 26, and an audible and visual warning light 27, constructing a multi-layered active safety protection mechanism for the equipment in a dark tunnel environment. The enclosure 22 houses a power supply unit, a main control computer, and a communication module. The touchscreen display 24, environmental sensing camera 25, obstacle detection radar 26, audible and visual warning lights 27, and communication module are all connected to the main control computer. The power supply unit is electrically connected to the energy storage battery pack, and it performs voltage transformation and distribution of the energy from the battery pack.

[0060] The lifting device 3 is fixedly mounted on the chassis frame 11 within the traveling chassis 1, and is used for the one-dimensional linear translational motion of the multi-degree-of-freedom robotic arm 5 and the detection module 6. The lifting device 3 provides large-stroke Z-axis compensation to cope with the large height variations within the tunnel, such as... Figure 5 As shown, the lifting device 3 includes two lifting mechanisms 31 fixedly mounted on the base 21 and located in the inverted V-shaped grooves on both sides of the housing 22. Existing technology can be used, preferably a high-thrust electric push rod with a mechanical self-locking structure. The two lifting mechanisms 31 are rigidly connected to the main control box 21 through the base fixing plate, and an inclined fixing bracket 32 ​​is provided at the bottom to eliminate lateral deformation.

[0061] The main control computer uses a cross-coupled PID synchronous control algorithm to synchronously drive the two segmented sleeve lifting mechanisms 31 (electric push rods) to achieve strictly equal displacement lifting and prevent jamming. Specifically, the main control computer reads the displacement feedback values ​​y1 and y2 of the lifting ends (vertical displacement of the end push rods in the two electric push rods) of the two segmented sleeve lifting mechanisms 31 in real time. Given a target displacement γ, it calculates the displacement tracking errors e1=γ-y1 and e1=γ-y2 respectively, and simultaneously calculates the synchronization error ɛ=y1-y2. When calculating the target speeds U1 and U2 of the motors in the two segmented sleeve lifting mechanisms 31 (the "target speed command" output by the main control computer to the drive motor), the main control computer not only includes its own displacement error PID adjustment but also introduces the synchronization error ɛ for compensation, resulting in U1=PID(e1)-K·ɛ and U2=PID(e2)+K·ɛ, where K is the synchronization compensation gain coefficient. To conform to the actual physical logic of cross-coupling control—that is, if one side has a larger error and needs to decelerate, the other side needs to accelerate to catch up—the signs of the two compensation terms should be one positive and one negative. This algorithm can eliminate the displacement difference between the push rods on both sides caused by uneven mechanical load in real time, ensuring strictly equal horizontal displacement of the horizontal displacement mechanism 4.

[0062] In the event of an unexpected power outage, the internal mechanical self-locking structure of the segmented sleeve lifting mechanism 31 ensures that the high-value robotic arm and inspection equipment above will not fall. A horizontal slide mounting plate 33 is provided at the top of the telescopic rod of the segmented sleeve lifting mechanism 31 for fixing the horizontal displacement mechanism 4. The horizontal displacement mechanism 4 is clamped and fixed to the horizontal slide mounting plate 33 by a horizontal slide mounting clamp 34.

[0063] The horizontal displacement mechanism 4 is mounted on the lifting device 3, providing one-dimensional or two-dimensional linear translational motion. The horizontal displacement mechanism 4 is supported on the horizontal slide mounting plate 33 of the lifting device 3, constructing a linear extension domain in the Y-axis direction. For example... Figure 6As shown, the horizontal displacement mechanism 4 includes a horizontal slide 41 and a robotic arm mounting base 43. The horizontal slide 41 is fixedly mounted on the horizontal slide mounting plates 33 of the two segmented sleeve lifting mechanisms 31, and is further clamped and fixed by the horizontal slide mounting clamps 34. The two segmented sleeve lifting mechanisms 31 operate synchronously, driving the horizontal slide 41 to rise and fall as a whole. The main body of the horizontal slide 41 adopts a high-rigidity linear module, which can use the existing screw and nut pair moving mechanism. It integrates a high-precision guide rail and a screw transmission pair, and the screw is driven by a drive motor 42. The robotic arm mounting base 43 is fixedly mounted on the horizontal slide 41 through a slider connector. The robotic arm mounting base 43 is equipped with a robotic arm positioning block 44 and a robotic arm positioning pin 45. The drive motor 42 monitors the operating current in real time. When the slider connector on the horizontal slide 41 encounters unexpected resistance during translation (such as touching a drooping cable), it can trigger compliant anti-collision protection based on the current change. The robotic arm mounting base 43 provides an installation interface for the multi-degree-of-freedom robotic arm 5. The robotic arm positioning block 44 and the robotic arm positioning pin 45 are used to install and fix the multi-degree-of-freedom robotic arm 5. In addition, limiters are set at both ends of the horizontal slide table 41 in conjunction with photoelectric switches to form a dual soft and hard stroke limit protection. The robotic arm mounting base 43 allows the robotic arm to effectively expand its working envelope at the top of the tunnel by sliding the slider along the guide rail, avoiding the interference risk caused by simply increasing the arm span.

[0064] The multi-degree-of-freedom robotic arm 5 is mounted on the movable end of the horizontal displacement mechanism 4, enabling it to translate along with the mechanism and possessing multiple rotary joints for multi-dimensional spatial posture adjustment. For example... Figure 7 As shown, the multi-degree-of-freedom robotic arm 5 employs a six-axis flexible collaborative robotic arm, which is existing technology. The robotic arm base 51 is fixedly mounted on the robotic arm mounting base 43, and the overall positioning of the multi-degree-of-freedom robotic arm 5 is achieved through the robotic arm positioning block 44 and the robotic arm positioning pin 45. The end joint 54 of the multi-degree-of-freedom robotic arm 5 is fixedly engaged with the quick-connect flange 61 in the detection module 6. The overall movement of the multi-degree-of-freedom robotic arm 5 is constructed through the cascaded combination of the robotic arm base 51, the upper arm 52, the lower arm 53, and the end joint 54, forming an extremely flexible three-dimensional working spherical envelope. Each joint has a built-in dual encoder and torque sensor, which can flexibly navigate around obstacles such as rigid contact wires and lighting cables distributed on the top and side walls of the tunnel through the linkage of each joint, delivering the end detection module to a hidden area or narrow gap behind the obstacle. It can not only accurately execute complex spatial kinematic inverse trajectories, but also achieve smooth obstacle avoidance and insertion in extremely narrow pipelines.

[0065] The detection module 6 is mounted on the end of the multi-degree-of-freedom robotic arm 5 (see...). Figure 7 This is controlled by the main control computer and is used to acquire images and depth data of the tunnel roof. For example... Figure 8As shown, the detection module 6 includes a quick-connect flange 61, a mounting bracket 62, and a detection box 63. The detection box 63 is fixedly mounted on the mounting bracket 62, which is equipped with a quick-connect flange 61. The quick-connect flange 61 is used to mount the multi-degree-of-freedom robotic arm 5 to its end joint 54, achieving lightweight integration of the front-end sensing equipment. The detection box 63 of the detection module 6 adopts a dual-modal architecture of "vision + laser." Specifically, an industrial-grade area array CCD camera and a high-frequency line laser contour scanner are arranged side-by-side in the sensor window 64 at its front, surrounded by a dynamically adjustable LED strobe light array to resist reflective interference from the tunnel wall and acquire shadowless, high-contrast defect images and depth point cloud data. The sensor window 64 enables multi-source data fusion acquisition of defects such as micro-cracks in the roof slab, segment misalignment, and water leakage.

[0066] The drive motor 14 in the drive chassis 1, the environmental perception camera 25, the obstacle detection radar 26, the drive motor 42 in the horizontal displacement mechanism 4, the joint drive servo motors in the multi-degree-of-freedom robotic arm 5, and the CCD camera and high-frequency line laser contour scanner in the detection module 6 are all communicatively connected to the main control computer in the main control box. The main control computer establishes wireless data communication with the cloud server through the communication module. The power input terminals of all the above-mentioned electrical components, as well as the driving lights 23 and the audible and visual warning lights 27, are electrically connected to the power supply unit in the main control box 2.

[0067] In actual inspection operations, the specific workflow of this invention is as follows.

[0068] Step 1: Power-on self-test preparation stage;

[0069] The inspection robot begins initialization and zero-position calibration. After being powered on on the subway track, the robot wakes up the bus network via the touch screen 24 and performs a full-node self-check. The walking chassis 1, lifting device 3, horizontal displacement mechanism 4, and multi-degree-of-freedom robotic arm 5 reset to the mechanical origin at low speed, establishing a unified global coordinate system. Subsequently, the LED strobe light array of the detection module 6 performs a test exposure, and the CCD camera and high-frequency line laser contour scanner perform a reference white balance calibration. Finally, after completing the above self-check and reset work, the main control computer turns on the front running lights 23 to prepare for departure.

[0070] Step 2: Addressing and Adaptive Cruise Control Phase;

[0071] The drive motor 14 receives the tunnel segment inspection task list from the main control computer and drives the walking chassis 1 to cruise along the track at a cruising speed. During this process, the environmental perception camera 25 and obstacle detection radar 26 located on the top of the main control box 2 perform real-time detection of the surrounding environment. If an emergency or obstacle is encountered, the inspection robot will brake suddenly and activate the audible and visual warning lights 27. At this time, the main control computer will record the abnormal information and report it to the cloud server in a timely manner. If there are no abnormalities during the cruise, the main control computer will continuously integrate the servo encoder odometer data and combine it with the segment joint characteristics to perform absolute coordinate correction until it accurately stops directly below the target segment where a roof defect is suspected.

[0072] Step 3: Multi-level pose joint calculation and dynamic obstacle avoidance operation;

[0073] This operational step is the most technologically advantageous aspect of the invention. Facing the dense overhead contact line and lighting pipelines at the tunnel ceiling, the main control computer automatically controls multi-axis collaborative obstacle avoidance. First, a coarse adjustment is performed: the main control computer controls the output end (push rod) of the lifting device 3 to rise, sending the horizontal displacement mechanism 4, the multi-degree-of-freedom robotic arm 5, and the detection module 6 to the safety boundary below the pipelines. Next, the horizontal displacement mechanism 4 translates to find the entry point. At this time, the drive motor 42 starts, controlling the robotic arm mounting base 43 of the horizontal displacement mechanism 4 to move laterally in the Y-axis direction, using the end vision of the multi-degree-of-freedom robotic arm 5 to find the optimal obstacle avoidance gap between the pipelines. Finally, the multi-degree-of-freedom robotic arm 5 is controlled for fine-tuning and weaving. After confirming the entry point, the multi-degree-of-freedom robotic arm 5 starts. Through its own control, the joints smoothly move in unison, like a snake, bypassing the contact line and precisely delivering the end joint 54 to the optimal focal length position only 15-20 cm from the roof surface.

[0074] Step 4: Seamless multi-source data acquisition for surface bonding;

[0075] After reaching the designated surface pose, the detection module 6 begins operation. The high-frequency line laser profilometer inside the detection box 63 emits structured light to extract the depth of the misalignment and cracks in the top plate, and an industrial-grade area array CCD camera simultaneously performs high-frequency continuous shooting; with the cooperation of the slight displacement of the robotic arm mounting base 43, push-broom panoramic image stitching is completed for this local blind area.

[0076] Step 5: Edge filtering, data return, and table reset / clearing;

[0077] The massive amounts of data collected by the detection module 6 are transmitted in real time to the main control computer in the main control box 2 for pre-screening. After invalid frames are removed, the data is packaged and uploaded to the cloud server. Subsequently, following the reverse safety trajectory of step 3, the multi-degree-of-freedom robotic arm 5 retracts and folds to the anti-collision protection posture, the horizontal slide 41 returns to the center, and the output end (push rod) of the lifting device 3 is lowered to the lowest center of gravity position. The walking chassis 1 releases the brakes and moves at full speed towards the next target section.

Claims

1. A track-mounted intelligent inspection robot for subway tunnels, characterized in that, It includes a walking chassis, main control box, lifting device, horizontal displacement mechanism, robotic arm, and detection module; The traveling chassis includes a chassis frame and a drive mechanism mounted on the chassis frame, with an encoder in the drive mechanism; the chassis frame is used to carry the main control box and lifting device and moves along the subway tunnel track; Main control box: includes a box mounted on a chassis frame. The box contains a main control computer and a communication module. The box is equipped with a display screen, a camera, and an obstacle detection radar. The communication module, display screen, camera, and obstacle detection radar are all connected to the main control computer. The main control computer is connected to a cloud server through the communication module. Lifting device: Fixedly installed on the chassis frame or main control box, used to drive the horizontal displacement mechanism, robotic arm and detection module to lift and lower, so as to realize the one-dimensional linear translational motion of the detection module; Horizontal displacement mechanism: mounted on the lifting device, used to drive the robotic arm and detection module to move horizontally; Robotic arm: Mounted on the horizontal displacement mechanism, it moves in translating motion with the horizontal displacement mechanism and is used to perform multi-dimensional spatial posture adjustments for the detection module; The detection module includes a CCD camera and a laser contour scanner, which are mounted on a robotic arm and connected to the main control computer. It is used to acquire images and depth data of the tunnel roof. The electric components in the walking chassis, lifting device, horizontal displacement mechanism, and robotic arm are all connected to the main control computer in the main control box.

2. The intelligent inspection robot for subway tunnels based on claim 1, characterized in that, The drive mechanism in the chassis includes an active walking mechanism and a driven walking mechanism mounted on the chassis frame. The active walking mechanism includes a drive wheel mounting bracket mounted at the bottom of the chassis frame, and a drive motor and a reducer mounted on the drive wheel mounting bracket. The active end of the reducer is connected to the shaft of the drive motor, and the drive wheel is mounted on the power output end of the reducer. The driven walking mechanism includes a driven wheel mounting bracket mounted at the bottom of the chassis frame, and a driven wheel mounted on the driven wheel mounting bracket. The drive motor is a servo motor with an absolute encoder and a built-in power-off braking mechanism. Both the absolute encoder and the servo motor are connected to the main control computer.

3. The intelligent inspection robot for subway tunnels based on claim 1, characterized in that, The driven wheel is elastically mounted on the driven wheel mounting bracket via a shock-absorbing module.

4. The intelligent inspection robot for subway tunnels based on claim 1, characterized in that, The main control box is connected to the base, and the base is fixedly installed on the chassis frame of the walking chassis.

5. The intelligent inspection robot for subway tunnels based on claim 1, characterized in that, The side of the enclosure is provided with an inverted V-shaped groove, and a driving light is provided on the side of the enclosure. An audible and visual warning light is provided on the top of the enclosure. Both the driving light and the audible and visual warning light are electrically connected to the power supply unit located inside the enclosure.

6. The intelligent inspection robot for subway tunnels based on claim 1, characterized in that, The lifting device includes two lifting mechanisms, which are synchronously driven by a main control computer. The main control computer adopts a cross-coupled PID synchronous control algorithm. The specific process is as follows: The main control computer obtains the displacement feedback values ​​y1 and y2 of the lifting end in the two lifting mechanisms in real time. Given the synchronous target displacement γ, the displacement tracking errors e1=γ-y1 and e2=γ-y2 are calculated respectively, and the synchronous error ɛ=y1-y2 is calculated at the same time. The main control computer combines the PID adjustment of the displacement tracking errors e1 and e2 and introduces the synchronous error ɛ for compensation to calculate the target speeds U1 and U2 of the drive motors in the two lifting mechanisms, U1=PID(e1)-K·ɛ, U2=PID(e2)+K·ɛ, where K is the synchronous compensation gain coefficient.

7. The intelligent inspection robot for subway tunnels based on claim 1, characterized in that, The horizontal displacement mechanism includes a horizontal slide and a robotic arm mounting base. The horizontal slide is fixedly connected to the lifting device, and the robotic arm mounting base is fixedly installed on the horizontal slide through a slider connector. The robotic arm mounting base is provided with a robotic arm positioning block and a robotic arm positioning pin.

8. The intelligent inspection robot for subway tunnels based on claim 1, characterized in that, The detection module includes a quick-connect flange, a mounting bracket, and a detection box. The detection box is fixedly mounted on the mounting bracket, which is equipped with a quick-connect flange. The quick-connect flange is connected to the end of the robotic arm. The detection box contains the CCD camera and the laser contour scanner. The inner wall of the detection box is equipped with an array of strobe lights.

9. A method of using the intelligent inspection robot for subway tunnels as described in any one of claims 1-8, characterized in that, Includes the following steps: (1) Self-inspection preparation stage; The walking chassis, lifting device, horizontal displacement mechanism and robotic arm are reset to the mechanical origin to establish a unified global coordinate system, and the CCD camera and laser contour scanner in the detection module are calibrated for reference white balance. (2) Addressing and adaptive cruise phase; The chassis receives the tunnel segment inspection task list from the main control computer and cruises on the subway tunnel track. During the cruise, the camera and obstacle detection radar monitor the surrounding environment in real time. If an emergency or obstacle is encountered, the emergency power-off braking of the chassis is activated, and the main control computer records the abnormal information and reports it to the cloud server in a timely manner. If there are no abnormalities during the cruise, the main control computer calculates the mileage in real time and performs absolute coordinate correction in combination with the characteristics of the segment joints until it stops precisely under the target segment with suspected roof defects. (3) Dynamic obstacle avoidance operation; First, a coarse adjustment is performed. The main control computer controls the output end of the lifting device to rise, sending the horizontal displacement mechanism, robotic arm, and detection module to the safety boundary below the pipeline. Second, the horizontal displacement mechanism moves horizontally to find the entry point. The horizontal displacement mechanism controls the robotic arm to move laterally and uses the end vision of the robotic arm to find the optimal obstacle avoidance gap between the pipelines. Finally, the robotic arm is controlled to perform fine adjustment and insertion. After confirming the entry point, the robotic arm starts and delivers the end to the optimal focal length position from the top plate surface. (4) No blind spots in surface-mounted multi-source data acquisition; After the detection module reaches the designated surface pose, it begins to work; the laser profilometer emits structured light to extract the misalignment and crack depth of the top plate, and the CCD camera simultaneously performs high-frequency continuous shooting; with the assistance of the robotic arm, the push-broom panoramic image stitching of the local blind area is completed. (5) Edge filtering, backhaul and reset clearing; The data collected by the detection module is transmitted in real time to the main control computer in the main control box for pre-screening. After invalid frames are removed, the data is packaged and uploaded to the cloud server. Subsequently, the robotic arm, horizontal drive mechanism, and lifting device were reset, and the chassis was released from braking.

10. The method of using the track-mounted intelligent inspection robot for subway tunnels according to claim 9, characterized in that, In step (2), the process of the main control computer performing real-time mileage calculation is as follows: the main control computer reads the pulse data of the encoder of the chassis drive mechanism at fixed intervals. The diameter of the drive wheel in the chassis is D, and the rated number of pulses for one revolution of the encoder is P. The pulse increment read within the sampling period is The increase in mileage per cycle The main control computer continuously... Discrete integrals are accumulated, and combined with the initial starting coordinates, the absolute mileage coordinates of the chassis in the tunnel are calculated in real time.

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