A detection and repair robot with end vibration suppression capability and a working method thereof

Abstract

This invention belongs to the technical field of bridge defect detection and repair robots, and relates to a detection and repair robot with end-effector vibration suppression capability and its operating method. The robot includes a track and walking structure, a main beam truss, a telescopic truss, a negative pressure adsorption device, and an end-effector operating system. The track and walking structure is suspended on a bridge maintenance track, driving the robot to move longitudinally. The main beam truss serves as the load-bearing skeleton. The telescopic truss is located on both sides of the main beam truss, expanding or contracting laterally along the bridge to cover the bottom, sides, and flange bottom areas of beams of varying widths. The negative pressure adsorption device is located at the end of the telescopic truss, forming a negative pressure adsorption connection with the outer surface of the bridge during operation, increasing the equivalent stiffness of the end-effector to suppress the impact of bridge vibration on the end-effector operation. The end-effector operating system includes a cooperating arm and various detection and repair tools. This invention solves the problems of fragmented detection and repair, insufficient full-section coverage, and difficulty in end-effector vibration suppression in existing technologies.

Description

Technical Field

[0001] This invention belongs to the field of bridge defect detection and repair robot technology, and relates to a detection and repair robot with end-effector vibration damping capability and its operation method. Background Technology

[0002] The main girder of a bridge is the core load-bearing component that supports vehicle loads, wind loads, temperature effects, and the effects of material aging. The outer surface of the main girder of bridges spanning rivers, seas, and urban viaducts is constantly exposed to high humidity, salt spray, strong winds, and vehicle vibration, making it prone to defects such as concrete cracks, localized spalling, surface cracks in the steel structure, corrosion, and paint deterioration. Traditional inspection and maintenance methods mainly rely on bridge inspection vehicles, scaffolding, suspended platforms, manual rope work, or drone photography. These methods suffer from drawbacks such as high risks associated with personnel working at heights, insufficient coverage of blind spots such as the center of the girder bottom and the bottom surface of the flanges, reliance on manual experience for inspection results, separation of inspection and repair, and difficulty in timely in-situ repairs.

[0003] Based on a survey of existing patents and publicly available competing products in China, existing technologies can be broadly categorized into three types: track-mounted bridge inspection robots, bridge defect repair devices, and track-based mobile control systems. While these technologies have driven the shift in bridge inspection from manual visual inspection to machine vision inspection, significant shortcomings remain in areas such as integrated inspection and repair of the main beam's outer surface, dynamic full-section coverage, stable end-effector operation, and long-distance high-precision positioning.

[0004] (a) Track-mounted bridge inspection robots.

[0005] A bridge inspection robot (CN111794100B) developed by China Railway Bridge Bureau proposes a T-shaped track-based robot. The track is installed on the side web of the bridge, and the walking mechanism slides along the track via a clamping drive device. Cameras are mounted on the fixed and rotating arms at the ends of the connecting arms to capture images of the flanges, web, and bottom plate, respectively. This technology is suitable for scenarios with limited space under the beams of dual-purpose road-rail bridges, but it still has the following limitations: the connecting arms are of fixed length, only covering a preset inspection range, making it difficult to adapt to different beam widths and bridge types; it only has visual inspection capabilities and does not disclose its ability to repair defects; it does not address long-distance positioning and correction mechanisms; and it does not disclose end-point vibration suppression measures under bridge vibration environments.

[0006] Angushun Machinery Technology's track-mounted bridge inspection robot (CN118636173B), equipped with visual inspection equipment, completes bridge beam bottom inspections along a preset track, primarily addressing the automation of bridge surface inspection. Its shortcomings include: its functionality remains limited to inspection tasks, lacking the ability to directly perform repairs after inspection; it has not disclosed a telescopic truss structure or full-section coverage scheme; and it lacks end-point stability control and high-precision positioning correction mechanisms for surface-facing bridge vibration environments.

[0007] The Guizhou Transportation Vocational University / Huajiang Canyon Bridge track-based intelligent inspection robot system adopts a three-track high-strength aluminum alloy track design, which can withstand strong winds and adapt to the high humidity environment of the canyon, and can identify a variety of common defects. Its limitations are: its core function remains detection and identification, and its automatic repair capabilities are not disclosed; its three-track configuration is relatively large, and it does not employ lightweight full-section coverage solutions such as telescopic trusses; and it does not cover the use of collaborative arms to carry multiple types of repair tools and a closed-loop repair process.

[0008] Publicly available information on the Southwest Jiaotong University's series of track-mounted beam bottom inspection robots shows that related products or prototypes are equipped with a six-degree-of-freedom long arm, an automatic focusing vision system, multiple stabilization controls, and an environmental reconstruction scanning system, which can be used for inspecting beam bottom defects in steel main beam bridges and concrete beam bridges. However, their shortcomings include: their functions are mainly focused on defect identification and location, lacking the ability to directly perform repair work such as crack sealing, glue injection, spalling filling, and rust grinding and spraying after inspection; the positioning accuracy of some products is only at the centimeter level, which is insufficient to meet the requirements of precision repair operations for end-effector positioning and trajectory control; the end-effector negative pressure adsorption vibration suppression scheme for the continuous micro-vibration environment of bridges is not disclosed; and the robotic arms are mostly single fixed-arm extensions, making it difficult to achieve dynamic coverage of the entire main beam cross-section through telescopic trusses.

[0009] (ii) Bridge damage repair devices.

[0010] The concrete bridge defect repair device (CN220953030U) mainly consists of grouting equipment and a traveling trolley, used for grouting and sealing bridge cracks. This device still relies on manual operation and hand-pushing, and cannot replace personnel for autonomous high-altitude operations on the outer surface of the main beam; its function is limited to grouting single cracks, and it cannot provide differentiated treatment based on crack width; it also cannot handle other types of defects such as concrete spalling, steel structure corrosion, and paint deterioration, and it lacks autonomous track movement and a closed-loop detection-repair capability.

[0011] This self-generating, multi-functional robot for detecting and repairing concrete cracks uses biomimetic walking legs and a multi-functional repair arm to detect and repair cracks in concrete pavements or bridge decks. Its shortcomings include: its walking method is crawling or walking, making it difficult to adapt to high-altitude external surface working environments such as the bottom, sides, and flange bottom surfaces of bridge main beams; its repair function mainly targets concrete cracks, not covering steel structure corrosion and concrete spalling; and its biomimetic walking legs have a complex structure, resulting in insufficient reliability and safety redundancy in the high-altitude, narrow, and windy environments of bridges.

[0012] (iii) Rail-based mobile control systems.

[0013] The rail-guided inspection robot's walking control system (CN119225380A) automatically switches to the corresponding target speed for driving control based on the sub-path type of the robot's track. Its shortcomings are: it only involves segmented speed control, failing to address the cumulative errors caused by encoder positioning coefficient drift, track gradient, and turns in long-distance bridge tracks; it does not address the coupling effects of bridge micro-vibrations, wind loads, and reaction forces from end-of-line repair operations; and it lacks telescopic trusses, collaborative arm maintenance mechanisms, and defect repair tools, thus preventing the repair of the outer surface of the bridge's main beam.

[0014] In summary, the main drawbacks of existing technologies are as follows: (1) The detection and repair are separated, making it impossible to achieve "integrated inspection and repair". Existing track-mounted bridge inspection robots are mostly focused on the detection and identification of defects, and do not have the ability to carry out repair work directly on the bridge deck. After the problem is detected, manual or separate equipment intervention is still required for repair, the operation cycle is long, secondary positioning is difficult, and the risk of high-altitude operation still exists.

[0015] (2) The mechanical structure is not flexible enough to adapt to different beam widths and full cross-section coverage requirements. The detection arms of existing robots are mostly fixed length or limited rotating arms with fixed arm span, which cannot dynamically extend and retract to cover the bottom, side and flange bottom surfaces of bridges with different beam widths.

[0016] (3) Lack of end-effector stability control methods in bridge vibration environment. Long-span bridges are in a state of continuous micro-amplitude vibration under the coupled action of vehicle dynamic load, wind load and temperature stress. Existing inspection robots are usually not equipped with end-effector adsorption stabilization devices, which can easily cause blurry inspection images and insufficient repair positioning accuracy.

[0017] (4) The repair methods for bridge defects are limited and lack the ability to classify and repair defects. Most existing bridge repair devices can only perform single grouting or local treatment, and cannot implement differentiated repair strategies based on crack width, spalling depth, corrosion range and the structural location of the defects.

[0018] (5) Insufficient positioning accuracy over long distances. Most existing positioning schemes for track-guided robots use a single encoder and fixed coefficients, which are difficult to overcome coefficient drift caused by track slope, turning radius changes, friction wheel slippage, and track dust or water accumulation. The cumulative error increases after long-distance operation. Summary of the Invention

[0019] In view of this, the purpose of the present invention is to provide a detection and repair robot with end-effector vibration suppression capability and its operation method, which can stably run along the inspection track on the outer surface of the main beam and effectively suppress the vibration at the end of the long arm, so as to perform accurate, stable and comprehensive detection and in-situ repair on the bottom, sides and flange bottom areas of the beam.

[0020] To achieve the above objectives, the present invention provides the following technical solution: A detection and repair robot with end-effector vibration damping capability includes a track and walking structure, a main beam truss, a telescopic truss, a negative pressure adsorption device, and an end-effector operation system. The hanging rail and walking structure are used to suspend and travel on the maintenance rail at the bottom or side of the bridge, driving the robot to move longitudinally along the bridge. The main beam truss is connected to the hanging rail and the walking structure, serving as the robot's load-bearing skeleton; The telescopic truss is installed on both sides of the main beam truss and can be extended or retracted along the transverse direction of the bridge to cover the bottom, sides, flange bottom surface and cantilever area of ​​bridges with different beam widths. The negative pressure adsorption device is installed at the end of the telescopic truss and is used to form a negative pressure adsorption connection with the outer surface of the bridge during the inspection or repair process, so as to improve the equivalent stiffness of the end and suppress the impact of bridge vibration on the end operation. The end-of-line working system is located at the end of the telescopic truss and includes a cooperating arm, a quick-change device connected to the cooperating arm, and multiple inspection tools and repair tools arranged on the quick-change device. The cooperating arm is used to drive the quick-change device and repair tools to the working area at the bottom of the bridge beam, the side of the beam, and the bottom of the flange. The quick-change device is used to switch between different inspection tools and repair tools to achieve integrated operation of defect detection and in-situ repair.

[0021] Furthermore, the rail-mounted and traveling structure includes a drive motor, a rail-mounted drive wheel, a fall arrestor, a suspended load-bearing base, guide wheels, and a rail-mounted and traveling frame. The rail-mounted drive wheel is rotatably mounted in the rail-mounted and traveling frame and suspended from the maintenance rail at the bottom or side of the bridge. The drive motor is mounted on the outside of the rail-mounted and traveling frame and outputs driving force to the rail-mounted drive wheel to move the robot longitudinally along the bridge. The guide wheels are rotatably mounted in the rail-mounted and traveling frame and positioned at both ends in the robot's traveling direction to guide the robot along the maintenance rail and reduce the risk of jamming. The fall arrestor is installed in the rail-mounted and traveling frame and positioned above the rail-mounted drive wheel to provide fall protection. The suspended load-bearing base is connected to the bottom of the rail-mounted and traveling frame via a load-bearing connector to connect to the main beam truss.

[0022] Furthermore, the negative pressure adsorption device includes a lifting platform, a universal support platform, a high-pressure fan, an adsorption chamber, and a sealing skirt. The lifting platform is installed at the end of the telescopic truss, the adsorption chamber is connected to the lifting platform via the universal support platform, the sealing skirt is arranged on the outer circumference of the adsorption chamber, and the high-pressure fan is arranged on the adsorption chamber for evacuating air from the adsorption chamber. The lifting platform drives the adsorption chamber to approach the outer surface of the main beam, the universal support platform allows the adsorption chamber to adapt to local angle changes on the outer surface of the main beam, and after the sealing skirt is in contact with the outer surface of the bridge, the high-pressure fan creates negative pressure inside the adsorption chamber. When the adsorption negative pressure reaches a set threshold and stabilizes, the end-operation system then performs detection or repair actions.

[0023] Furthermore, the telescopic truss includes a movable truss, a fixed truss, a rack, a telescopic drive motor, and guide limiting plates. The fixed truss is fixed to the main beam truss and arranged parallel to the beam side of the bridge. The movable truss is slidably arranged within the fixed truss. The guide limiting plates are installed in the fixed truss and located on both sides of the movable truss to constrain the movement direction and limit the movement range of the movable truss. A rack is provided at the bottom of the movable truss, and the telescopic drive motor is provided in the fixed truss. The telescopic drive motor drives the movable truss to extend or retract laterally along the bridge through the rack, and the movable trusses at both ends of the main beam truss extend or retract synchronously, keeping the robot's center of gravity in the middle of the maintenance track to reduce the lateral additional load on the maintenance track.

[0024] Furthermore, the detection tool of the end-of-line system includes a 3D guiding camera for acquiring the three-dimensional shape of the damaged area and guiding the tool's posture. The repair tool includes one or more of a crack sealing repair tool, a peeling repair tool, a pneumatic grinding device, and a pneumatic spraying device. The crack sealing repair tool includes a smooth steel plate connected to the quick-change device and epoxy sealant channels formed by several staggered sealing rubbers arranged on the side of the smooth steel plate away from the quick-change device.

[0025] Furthermore, it also includes a mobile vehicle equipped with an end-effector system, mounted on a customized track on the main beam truss. The mobile vehicle includes a vehicle body, a camera mounted on the vehicle body, a laser ranging module, lateral limiting wheels, vertical limiting wheels, and drive wheels. The camera and laser ranging module provide data for defect location identification, end-effector system attitude adjustment, and repair quality re-inspection. The lateral and vertical limiting wheels restrict the mobile vehicle's deviation on the customized track.

[0026] Furthermore, a segmented and directional correction fusion positioning method using an encoder and NFC dual-sensor linked to the drive motor is adopted: the maintenance track is divided into several homogeneous sections based on the track gradient, turning radius, and environmental conditions. NFC positioning markers are set at the endpoints of the sections, and an NFC reading device for reading these markers is installed on the main beam truss. Absolute position is corrected using NFC positioning information at the section endpoints, and recursive positioning is performed within the sections using encoder coefficients after directional correction. The encoder position and NFC position are fused using Kalman filtering to reduce cumulative positioning errors during long-distance track operation.

[0027] The present invention also provides a working method based on the above-described robot, comprising the following steps: S1. Task planning and positioning: Pre-set the path and target section of the robot along the maintenance track, control the robot to travel along the longitudinal track of the bridge to the target area, and deploy the telescopic truss to cover the target work area; S2. Defect Detection and Identification: Utilize detection tools to obtain information on the location, morphology, and type of defects on the bridge's outer surface; S3. Adsorption stabilization: After starting the negative pressure adsorption device and forming a negative pressure adsorption connection with the outer surface of the bridge, the repair work begins; S4. Categorized Repair: Select the corresponding repair strategy according to the type of disease and parameters. The collaborative arm drives the corresponding repair tools to perform in-situ repair after switching through the quick-change device. S5. Quality Re-inspection and Closed Loop: After the repair is completed, the repaired area is re-inspected using testing tools. If the re-inspection fails, return to step S4 for rework. If the re-inspection passes, the repair work is completed.

[0028] Furthermore, the classification repair in step S4 includes: For concrete cracks, treatment is categorized according to crack width: When the crack width is less than 0.15mm, the crack sides are ground and cleaned, and then a sealant is sprayed to seal the surface; when the crack width is between 0.15mm and 0.5mm, the crack is ground, blown, and cleaned, and then repaired using low-pressure injection, maintaining pressure until the sealant cures; when the crack width is greater than 0.5mm, or is a crack in an active joint, a seepage joint, or a crack in a critical stress area, the location of the defect is marked and uploaded to the platform for manual evaluation and treatment. For concrete spalling, if the spalled area does not expose the reinforcement and the depth is no more than 30mm, the base surface should be cleaned and the spalled area should be filled in layers after extending the work area outward by no less than 30mm; otherwise, it should be marked and handled manually. For steel main beams with rust or coating defects, if the failure is localized and does not affect the structural bearing capacity, the coating or metal substrate should be ground down to the intact coating and then sprayed for repair; otherwise, manual assessment will be required. Furthermore, after adsorption stabilizes in step S3, the end displacement is monitored in real time using the detection tool during the repair operation. If the end displacement exceeds a set threshold, the negative pressure adsorption pressure is adjusted. If the wind speed or vibration acceleration exceeds a set threshold, the adsorption negative pressure is increased, and the negative pressure adsorption device maintains adsorption during the switching of repair tools.

[0029] The beneficial effects of this invention are as follows: 1. This invention integrates a rail-mounted mobile vehicle, a spatial truss, symmetrical telescopic double arms, a cooperative arm, a negative pressure adsorption stabilization system, and a multimodal detection system into one unit. It can achieve longitudinal bridge movement and transverse bridge deployment coverage in a high-altitude environment on the outer surface of the main beam, solving the problem that traditional blind spots such as the center of the beam bottom, the bottom surface of the flange, and the inclined surface of the bridge side are difficult to reach.

[0030] 2. This invention adopts a suspended space truss and lightweight structure, and maintains the stability of the machine's center of gravity through multiple rail drive wheel sets, anti-fall wheels, anti-fall rods and synchronous telescopic control, so that the maintenance track mainly bears the vertical tension, reduces the lateral additional load, and improves the safety of high-altitude rail operations.

[0031] 3. This invention improves the stiffness of the telescopic truss end by using a negative pressure adsorption module in conjunction with the end of the negative pressure adsorption module, thus maintaining the stability of the end posture under the combined action of low-frequency vibration of the bridge, wind load, and reaction force of the repair tool. The adsorption negative pressure closed-loop compensation and the partitioned alternating adsorption strategy can reduce transient impacts during the repair process, improve the clarity of the detection image, the accuracy of the repair trajectory, and the consistency of repair quality.

[0032] 4. This invention adopts a segmented and directional correction fusion positioning method using both encoder and NFC dual sensors. Instead of using fixed encoder coefficients to process the entire track, it dynamically identifies coefficients based on track segments and movement directions and performs Kalman fusion, which can effectively reduce the cumulative positioning error under long-distance complex tracks.

[0033] 5. This invention integrates defect detection and in-situ repair into a complete closed-loop process, overcoming the shortcomings of existing technologies where detection and repair are separated, and manual or separate equipment is still required for secondary positioning and repair after detection. Specifically, after defect identification is completed by a 3D guiding camera, a webcam, and a laser ranging module integrated on the same robotic platform, the control system can automatically select sealing, seepage injection, layered filling, grinding and rust removal, spraying, or manual evaluation strategies based on crack width, spalling depth, rust range, and the location of key stress areas. A quick-change device allows direct switching to the corresponding repair tool at the same work site to perform in-situ repair, eliminating the need to rebuild bridge inspection equipment or perform secondary high-altitude work manually. The three-dimensional morphological data, location coordinates, and classification parameters of the defects obtained during the detection phase are directly used as input parameters for the repair phase. Real-time operational data collected during the repair process is automatically correlated with the re-inspection data after repair, forming a complete closed-loop operation from "defect detection—defect location—classification judgment—in-situ repair—quality re-inspection," significantly shortening the time interval between detection and repair, and reducing secondary positioning errors and the risk of repeated high-altitude work.

[0034] 6. The repair quality re-inspection of this invention uses a camera, a 3D guided camera, and a laser rangefinder to verify the appearance, contour, and flatness, and uploads the inspection, repair, and re-inspection data to form an archive, which is conducive to the digitalization, standardization, and traceability of bridge maintenance.

[0035] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0036] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of a detection and repair robot with end-effector vibration damping capability arranged on the outer surface of the main beam in an embodiment. It shows the overall arrangement relationship of the main beam truss, hanging rail and walking structure, negative pressure adsorption device, telescopic truss, mobile vehicle and end-effector operation system. Figure 2 This is a three-dimensional structural diagram of a detection and repair robot with end-effector vibration damping capability arranged on the outer surface of the main beam in the embodiment. Figure 3 This is a schematic diagram of the hanging rail and traveling structure in the embodiment, showing the arrangement of the drive motor, hanging rail drive wheel, anti-fall bar, suspension load-bearing base, load-bearing connector, and guide wheel; Figure 4The diagram shows the structure of the negative pressure adsorption device in the embodiment, including components such as the lifting platform, universal support platform, adsorption connector, high-pressure fan, adsorption chamber, and sealing skirt. Figure 5 The diagram shows the structure of the telescopic truss in the embodiment, including components such as the telescopic truss, fixed truss, rack, telescopic drive motor, and guide limit plate. Figure 6 The diagram shows the structure of the mobile vehicle in the embodiment, illustrating the arrangement of the camera, laser ranging module, lateral limiting wheel, vertical limiting wheel, custom track, and drive wheel. Figure 7 The diagram shows the structure of the end-effector system in the embodiment, illustrating the connection relationships of the collaborative arm, peeling repair tool, 3D guiding camera, crack sealing repair tool, pneumatic grinding device, pneumatic spraying device, and quick-change device. Figure 8 This is a schematic diagram of the crack sealing and repair tool in the embodiment, illustrating the principle of repairing cracks using this crack sealing and repair tool; Figure 9 This is a schematic diagram of a positioning scheme for a detection and repair robot with end-effector vibration damping capability based on encoders and NFC in an embodiment, illustrating the relationship between track segmentation, NFC absolute positioning, encoder recursive positioning, and information fusion. Figure 10 This is a flowchart of an operation method for an inspection and repair robot with end-effector vibration damping capability.

[0037] Reference numerals: 1-Main beam truss; 11-Gantry frame; 2-Hanging rail and traveling structure; 3-Negative pressure adsorption device; 4-Telescopic truss; 5-Mobile vehicle; 6-End-of-line operation system; 21-Drive motor; 22-Hanging rail drive wheel; 23-Anti-fall rod; 24-Suspension load-bearing base; 25-Load-bearing connector; 26-Guide wheel; 27-Hanging rail and traveling frame; 31-Lifting platform; 32-Universal load-bearing platform; 33-Adsorption connector; 34-High-pressure fan; 35-Adsorption chamber; 36-Sealing skirt; 41-Mobile truss; 42-Fixed truss Frame; 43-Rack; 44-Telescopic drive motor; 45-Guide limiting plate; 46-Fixed bracket; 51-Camera; 52-Laser ranging module; 53-Horizontal limiting wheel; 54-Vertical limiting wheel; 55-Custom track; 56-Drive wheel; 61-Collaborative arm; 62-Peeling repair tool; 63-3D guiding camera; 64-Crack sealing repair tool; 641-Smooth steel plate; 642-Sealing rubber; 643-Epoxy sealant channel; 65-Pneumatic grinding device; 66-Pneumatic spraying device; 67-Quick change device. Detailed Implementation

[0038] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0039] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0040] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0041] First, it should be noted that the directional terms such as "bottom," "top," "front end," "rear end," "both sides," "longitudinal," and "lateral" used in this invention are based on the installation and operation status of the inspection and repair robot shown in the accompanying drawings, and should not be construed as limiting the scope of protection of this invention. "Longitudinal" or "longitudinal bridge direction" refers to the direction along the length of the bridge, i.e., the direction in which the robot travels along the inspection track; "lateral" or "lateral bridge direction" refers to the direction perpendicular to the length of the bridge, i.e., the direction in which the telescopic truss unfolds or retracts. Furthermore, the camera 51, laser ranging module 52, 3D guiding camera 63, collaborative arm 61, high-pressure blower 34, drive motor 21, telescopic drive motor 44, pneumatic grinding device 65, pneumatic spraying device 66, and quick-change device 67 in this embodiment can all be implemented using existing mature components or modules, and their specific internal structures will not be described in detail here.

[0042] Example 1 like Figure 1 and Figure 2As shown, this embodiment provides a detection and repair robot with end-effector vibration damping capability, including a main beam truss 1, a rail and walking structure 2, a negative pressure adsorption device 3, a telescopic truss 4, a mobile carrier 5, and an end-effector operation system 6.

[0043] The main girder truss 1, serving as the load-bearing skeleton of the entire structure, adopts a spatial truss structure, its overall shape resembling a gantry frame extending longitudinally along the bridge. For example... Figure 1 As shown, gantry frames 11 are provided at both ends of the main beam truss 1. The gantry frames 11 serve as end supports for the main beam truss 1 in the transverse direction, connecting the hanging rail and the traveling structure 2. The gantry frames 11 are connected to the hanging rail and the suspended load-bearing base 24 of the traveling structure 2 via bolts. The weight of the entire robot is transmitted to the hanging rail drive wheel 22 through the suspended load-bearing base 24, and finally to the maintenance track at the bottom or side of the bridge. This suspended layout allows the maintenance track to mainly bear vertical tension, which helps to reduce the lateral additional load on the track.

[0044] like Figures 1-2 As shown, there are four hanging rails and walking structures 2, which are installed above the main beam truss 1 and used to suspend and walk on the maintenance rails at the bottom or side of the bridge, driving the robot to move longitudinally along the bridge; specifically, hanging rails and walking structures 2 are provided on both sides of the gantry 11 at both ends of the main beam truss 1 to ensure the connection stability between the robot and the maintenance rails.

[0045] The telescopic truss 4 is located on both sides of the main girder truss 1 (i.e., at both ends along the transverse direction of the bridge), and can expand or contract laterally along the bridge to cover the bottom, sides, flange bottom surfaces, and cantilever areas of bridges with different beam widths. A negative pressure adsorption device 3 is located at the end of the telescopic truss 4, used to form a negative pressure adsorption connection with the outer surface of the bridge during inspection or repair. A mobile carrier 5 is mounted on the main girder truss 1, used to carry the end-effector system 6 and move along a customized track 55 on the main girder truss 1. The end-effector system 6 is installed on the mobile carrier 5 and the end of the telescopic truss 4, and uses a cooperating arm 61 to move various inspection and repair tools to the target work area.

[0046] The robot adopts a hierarchical layout of "suspension and walking above, extension and retraction coverage on both sides, and adsorption and stabilization at the end", which enables the robot to move longitudinally, extend laterally, and operate stably at the end in high-altitude, narrow, and windy environments on the outer surface of the main beam of the bridge. It can cover the bottom of the beam, the sides of the beam, the bottom surface of the flange, and the cantilever area, solving the problem of blind spots in areas such as the center of the bottom of the beam and the bottom surface of the flange in traditional operation methods.

[0047] like Figure 3 As shown, the rail-mounted and traveling structure 2 includes a drive motor 21, a rail-mounted drive wheel 22, a fall arrestor 23, a suspension load-bearing base 24, a load-bearing connector 25, a guide wheel 26, and a rail-mounted and traveling frame 27.

[0048] The rail and walking frame 27 is the main frame structure of the rail and walking structure 2. The rail drive wheel 22 is rotatably mounted in the rail and walking frame 27 and suspended from the maintenance track at the bottom or side of the bridge. Specifically, the flange of the rail drive wheel 22 is engaged with the rail surface of the maintenance track, and the driving force is transmitted through the friction between the wheel and the rail, enabling the robot to travel longitudinally along the track. In actual bridge maintenance, the maintenance track is usually pre-installed at the bottom or side of the main beam of the bridge to provide a walking path for the robot.

[0049] The drive motor 21 is mounted on the outside of the rail and the walking frame 27, and outputs driving force to the rail drive wheel 22. The drive motor 21 is connected to the rail drive wheel 22 through a reduction mechanism. When the drive motor 21 rotates, it drives the rail drive wheel 22 to rotate, thereby driving the whole machine to move longitudinally along the bridge. The drive motor 21 can be a servo motor or a stepper motor to achieve precise control of the robot's walking speed and position.

[0050] Guide wheels 26 are rotatably mounted in the rail and the walking frame 27, and are located at both ends in the robot's walking direction. That is, guide wheels 26 are located at both the front and rear ends in the robot's walking direction. The function of the guide wheels 26 is to guide the robot as it travels along the track, helping it smoothly enter and pass through track curves, ramps, and track joints, reducing the risk of getting stuck. When the robot needs to move in the opposite direction, the guide wheels 26 that were originally at the rear end become the front end, still serving a guiding function.

[0051] The fall arrestor 23 is installed in the rail and traveling frame 27, and positioned above the rail drive wheel 22. The fall arrestor 23 and the rail drive wheel 22 form a clamping structure around the maintenance rail. During normal operation, the fall arrestor 23 maintains a certain distance from the rail and does not contact it. However, in extreme cases, such as when the rail drive wheel 22 accidentally derails, the fall arrestor 23 can lock itself above the rail, preventing the robot from falling further, thus providing fall protection for the robot when operating on high-altitude rails.

[0052] The suspended load-bearing base 24 is connected to the bottom of the hanging rail and the traveling frame 27 via the load-bearing connector 25. The suspended load-bearing base 24 is a transition structure connecting the upper traveling structure and the lower main beam truss 1. The robot's total weight is transferred through the suspended load-bearing base 24 to the hanging rail and the traveling frame 27 via the load-bearing connector 25, and then to the maintenance track. The load-bearing connector 25 uses high-strength bolts or pins for easy installation and disassembly.

[0053] Through the above structure, the rail-mounted and walking structure 2 enables the robot to reliably suspend and stably walk on the bridge maintenance track, and has functions such as guidance and anti-jamming, anti-fall protection and load transfer, providing a mobile foundation for subsequent inspection and repair operations.

[0054] like Figure 5 As shown, the telescopic truss 4 includes a movable truss 41, a fixed truss 42, a rack 43, a telescopic drive motor 44, and a guide limit plate 45.

[0055] Fixed trusses 42 are fixed at both ends of the main beam truss 1 and arranged parallel to the beam sides of the bridge. That is, fixed trusses 42 are installed at both ends of the main beam truss 1 along the transverse direction of the bridge, providing support and a sliding guide for the movable truss 41. The movable truss 41 is slidably arranged within the fixed truss 42, and can reciprocate along the transverse direction within the fixed truss 42, achieving a telescopic function. Guide limiting plates 45 are installed in the fixed truss 42 and located on both sides of the movable truss 41. The guide limiting plates 45 have two functions: first, to constrain the direction of movement of the movable truss 41, ensuring it can only move in a straight line along the transverse direction of the bridge, preventing the movable truss 41 from deflecting or swaying within the fixed truss 42; second, to limit the range of movement of the movable truss 41, preventing it from sliding out of both ends of the fixed truss 42, thus providing a limiting and protective function.

[0056] A rack 43 is provided at the bottom of the movable truss 41, and a telescopic drive motor 44 is provided in the fixed truss 42. A gear that meshes with the rack 43 is mounted on the output shaft of the telescopic drive motor 44. When the telescopic drive motor 44 rotates, the movable truss 41 is driven to extend or retract laterally along the bridge through the meshing transmission of the gear and the rack 43. This rack and pinion transmission method has the advantages of high transmission accuracy and strong load-bearing capacity, and can ensure the smooth movement of the movable truss 41 during the extension and retraction process.

[0057] Furthermore, a fixed support 46 is provided at the end of the movable truss 41 away from the fixed truss 42, and the negative pressure adsorption device 3 and the end operation system 6 are both arranged on the fixed support 46.

[0058] The telescopic trusses 4 at both ends (i.e., both sides) of the main beam truss 1 are driven by their own independent telescopic drive motors 44, and the telescopic trusses 4 on both sides extend or retract synchronously. "Synchronous" means that the moving trusses 41 on both sides extend to the sides or retract to the center simultaneously at the same speed and with the same stroke. The purpose of this design is to keep the robot's center of gravity as close as possible to the center of gravity below (i.e., in the middle) of the maintenance track, avoiding a shift in the center of gravity due to excessive extension or retraction on one side. Keeping the center of gravity in the middle reduces the lateral load on the maintenance track and improves the robot's stability when operating at heights. If the telescopic trusses 4 on both sides are not synchronized, for example, one side extends longer than the other, an eccentric moment will be generated, increasing the lateral force on the track and compromising safe operation.

[0059] By utilizing the telescopic function of the telescopic truss 4, the robot can adapt to bridges with varying beam widths. For narrower bridges, the telescopic truss 41 retracts to a smaller extension; for wider bridges, it extends to a larger extension. In this way, regardless of the bridge beam width, the end-effector system 6 can be guided to the target work area, achieving full coverage of the beam bottom, beam sides, flange bottom surface, and cantilever area.

[0060] like Figure 4 As shown, the negative pressure adsorption device 3 includes a lifting platform 31, a universal support platform 32, an adsorption connector 33, a high-pressure blower 34, an adsorption chamber 35, and a sealing skirt 36.

[0061] The lifting platform 31 is installed at the end of the telescopic truss 4 (i.e., the far end of the movable truss 41), and the lifting platform 31 can extend and retract in the vertical direction (i.e., up and down). When the robot reaches the area to be inspected or repaired, the lifting platform 31 drives the adsorption cavity 35 to move downwards, approaching the outer surface of the main beam. The stroke of the lifting platform 31 should be able to compensate for the distance difference between the end of the telescopic truss 4 and the outer surface of the main beam caused by the different cross-sectional shapes of the bridge, so that the adsorption cavity 35 can reliably reach and adhere to the outer surface of the main beam.

[0062] The adsorption chamber 35 is connected to the lifting platform 31 via the universal support platform 32. The universal support platform 32 is a connection structure that allows the adsorption chamber 35 to deflect at a certain angle relative to the lifting platform 31. Since the outer surface of the bridge main beam is not always a perfectly flat plane, there may be local unevenness, tilt, or corners. The universal support platform 32 allows the adsorption chamber 35 to automatically adapt to local angle changes on the outer surface of the main beam, ensuring that the sealing skirt 36 can fully fit with the outer surface of the main beam, thereby forming an effective sealing space. The adsorption connector 33 is used to connect the universal support platform 32 and the adsorption chamber 35, transferring the load-bearing capacity of the lifting platform 31 and the universal support platform 32 to the adsorption chamber 35.

[0063] A sealing skirt 36 is arranged on the outer circumference of the adsorption cavity 35. The sealing skirt 36 is made of a flexible material (e.g., rubber). When the adsorption cavity 35 approaches the outer surface of the main beam, the sealing skirt 36 first contacts and adheres to the outer surface of the main beam, forming a closed sealing boundary. The flexibility of the sealing skirt 36 allows it to adapt to minor unevenness on the outer surface of the main beam, ensuring a sealing effect. A high-pressure blower 34 is arranged on the adsorption cavity 35 and located in the hollow cavity formed by the adsorption connector 33, used to extract air from the adsorption cavity 35. Specifically, the high-pressure blower 34 extracts air from inside the adsorption cavity 35 to the outside, creating a negative pressure (i.e., a pressure state below atmospheric pressure) inside the adsorption cavity 35. Since the sealing skirt 36 has sealed the space between the adsorption cavity 35 and the outer surface of the main beam, the high-pressure blower 34 can maintain the negative pressure state of this space by continuously extracting air.

[0064] The working process of the negative pressure adsorption device 3 is as follows: After the robot arrives at the target work area, the telescopic truss 4 unfolds to the appropriate position; the lifting platform 31 drives the adsorption chamber 35 to approach the outer surface of the main beam; the sealing skirt 36 fits against the outer surface of the main beam to form a sealed space; the high-pressure blower 34 starts to extract air, so that a negative pressure is formed inside the adsorption chamber 35; when the adsorption negative pressure reaches the set threshold (e.g., not less than 15 kPa) and stabilizes for 2 to 3 seconds, a stable adsorption connection is formed between the negative pressure adsorption device 3 and the outer surface of the main beam. At this time, the control system allows the end-effector system 6 to perform detection or repair actions.

[0065] The core function of the negative pressure adsorption device 3 is vibration suppression. Because the main bridge beam is constantly under the coupled effects of vehicle dynamic loads, wind loads, and temperature stress, this vibration is transmitted to the end-effector system 6 through the telescopic truss 4, leading to blurred detection images and positioning errors. The negative pressure adsorption device 3 creates a "soft-rigid connection" (i.e., a somewhat elastic constraint connection established through negative pressure suction) between the end of the telescopic truss 4 and the outer surface of the main beam, improving the equivalent stiffness of the end-effector. "Equivalent stiffness" refers to the ability of the supporting structure to resist deformation from the perspective of the end-effector. When the adsorption chamber 35 is "held" by negative pressure to the outer surface of the main beam, the end-effector effectively gains an additional support point. Vibration transmitted to the end is suppressed by the negative pressure suction, thereby reducing the displacement amplitude of the end-effector relative to the outer surface of the main beam and improving operational stability.

[0066] During the repair operation, the negative pressure adsorption device 3 also has a dynamic compensation function. Specifically, the end displacement is monitored in real time by detection tools (such as camera 51 and laser ranging module 52). When the end displacement exceeds a set threshold (e.g., 0.5 mm), it indicates that the current adsorption force is insufficient to resist external disturbances. At this time, the control system will adjust the negative pressure adsorption pressure (e.g., increase the suction power of high-pressure fan 34) to increase the adsorption force and suppress end displacement. Similarly, when the ambient wind speed exceeds a set threshold or the bridge vibration acceleration exceeds a set threshold, the control system will also actively increase the adsorption negative pressure to enhance end stability.

[0067] When the end-of-line system 6 switches repair tools via the quick-change device 67, the negative pressure adsorption device 3 maintains its adsorption state without interruption. This is because if the adsorption force disappears during tool switching, the end-of-line tool may shift due to bridge vibration or wind, resulting in inaccurate tool positioning after switching. Maintaining the adsorption state ensures consistency in the end-of-line tool position before and after tool switching.

[0068] like Figure 6 As shown, the mobile vehicle 5 includes a vehicle body, a camera 51, a laser ranging module 52, a lateral limiting wheel 53, a vertical limiting wheel 54, a custom track 55, and a drive wheel 56.

[0069] Customized track 55 is installed on the main girder truss 1 and laid laterally along the bridge, providing a travel path for the mobile vehicle 5. The mobile vehicle 5 carries an end-effector system 6, which moves along the customized track 55 via drive wheels 56, enabling the end-effector system 6 to move to different positions along the lateral side of the bridge within the range of the main girder truss 1. In this way, even if the robot body remains stationary in a certain position, the mobile vehicle 5 can move the end-effector system 6 within the length of the main girder truss 1 to perform precise positioning and operations in localized areas.

[0070] Camera 51 is mounted on the upper surface of the vehicle body to acquire images of the outer surface of the bridge's bottom. Camera 51 can be a high-resolution industrial camera, capable of capturing clear images of the main beam's outer surface for defect location identification, defect morphology recording, and repair quality review. Laser ranging module 52 is also mounted on the vehicle body to measure the distance between the mobile vehicle 5 (i.e., the end-effector system 6) and the target on the outer surface of the main beam. Through laser ranging module 52, the distance of the end-effector tool relative to the bridge's outer surface can be accurately determined, providing distance data support for the end-effector tool's attitude adjustment and positioning. The combined use of camera 51 and laser ranging module 52 provides a complete data foundation for defect location identification, end-effector system 6 attitude adjustment, and repair quality review.

[0071] The lateral limiting wheel 53 and the vertical limiting wheel 54 are installed on the vehicle body at positions that mate with the customized track 55. The lateral limiting wheel 53 restricts the lateral deviation (i.e., left-right movement perpendicular to the track direction) of the mobile vehicle 5 on the customized track 55, and the vertical limiting wheel 54 restricts the vertical deviation (i.e., up-down bouncing perpendicular to the track direction) of the mobile vehicle 5 on the customized track 55. Through the joint constraint of the lateral limiting wheel 53 and the vertical limiting wheel 54, the mobile vehicle 5 can run smoothly close to the customized track 55, avoiding a decrease in the positioning accuracy of the end effector system 6 due to deviation or bouncing.

[0072] like Figure 7 As shown, the end-effector system 6 includes a collaborative arm 61, a peeling repair tool 62, a 3D guiding camera 63, a crack sealing repair tool 64, a pneumatic grinding device 65, a pneumatic spraying device 66, and a quick-change device 67.

[0073] The collaborative arm 61 is the core actuator of the end-effector system 6. It employs a multi-degree-of-freedom articulated arm structure, enabling flexible movement within the workspace. One end of the collaborative arm 61 is mounted on the mobile carrier 5, and the other end is equipped with a quick-change device 67. The function of the collaborative arm 61 is to drive the quick-change device 67 and the inspection and repair tools mounted on it to work areas such as the bottom of the bridge beam, the inclined side of the beam, and the bottom surface of the flange. Due to the complex geometry of the outer surface of the bridge main beam, including a horizontal bottom surface, inclined sides, and the flange bottom surface with the bottom surface facing upwards, the collaborative arm 61 needs sufficient degrees of freedom and reach to deliver the tools to these work areas at different angles and positions.

[0074] A quick-change device 67 is installed at the end of the collaborative arm 61 for rapid switching between different inspection and repair tools. The quick-change device 67 can employ mechanical or pneumatic locking, automatically disassembling and installing tools under the command of the control system. For example, when crack sealing repair is required, the quick-change device 67 installs the crack sealing repair tool 64; when surface polishing is required, the quick-change device 67 removes the crack sealing repair tool 64 and installs the pneumatic polishing device 65. During tool switching, the negative pressure adsorption device 3 maintains its adsorption state to ensure that the end position does not shift.

[0075] A 3D guided camera 63 is mounted on the quick-change device 67 as an inspection tool to acquire the three-dimensional morphology of the affected area. The 3D guided camera 63 can employ three-dimensional measurement technologies such as structured light or binocular vision to acquire depth information of the affected area, forming a three-dimensional model. The three-dimensional morphology data acquired by the 3D guided camera 63 allows for precise measurement of parameters such as the width and depth of cracks, the area and depth of spalling, and the extent of corrosion, providing a basis for disease classification and repair strategy selection. Simultaneously, the 3D guided camera 63 also guides the posture of the end effector of the collaborative arm 61, enabling the tool to be aligned with the affected area at the correct angle and distance for operation.

[0076] Furthermore, the quick-change device 67 is equipped with a camera 51 and a laser ranging module 52 arranged at the same station as the 3D guide camera 63.

[0077] Crack sealing and repair tool 64 is used for sealing concrete cracks. For example... Figure 8 As shown, the crack sealing and repair tool 64 includes a smooth steel plate 641 and sealing rubber 642. The smooth steel plate 641 is connected to the cooperating arm 61 via a quick-change device 67. Several sealing rubbers 642 are arranged alternately on the side of the smooth steel plate 641 away from the quick-change device 67. The gaps between the sealing rubbers 642 form epoxy sealant channels 643. During operation, the cooperating arm 61 presses the crack sealing and repair tool 64 firmly onto the concrete surface, with the smooth steel plate 641 facing the concrete crack and the sealing rubbers 642 adhering to the concrete surfaces on both sides of the crack. A seal is formed between the sealing rubbers 642 and the concrete surface, sealing the crack within the area enclosed by the sealing rubbers 642. Epoxy sealant flows into the crack area through the epoxy sealant channels 643. Because the crack sealing and repair tool 64 is pressed firmly against the concrete surface by the cooperating arm 61, the epoxy sealant, under pressure, penetrates deep into the crack through the injection semi-circular tube. The injection tube, with a diameter of 3mm, is made of high-hardness metal and features a high-precision polished surface, making it resistant to adhesive adhesion. The epoxy sealant inlet is connected to the injection tube, which in turn connects to an injection pump. The pump injects the epoxy sealant at a low pressure of approximately 0.25MPa and maintains this pressure for a certain period to allow for full penetration. After the sealant has cured, the cooperating arm 61 retracts the crack sealing and repair tool 64, completing the crack repair.

[0078] A spalling repair tool 62 is used for filling and leveling areas of spalled concrete. The spalling repair tool 62 may include a filler material storage container and an extrusion mechanism, capable of delivering filler materials such as repair mortar or repair concrete to the spalled area and compacting them. A pneumatic grinder 65 is used for surface cleaning of cracked, spalled, or corroded areas. Powered by compressed air, the pneumatic grinder 65 drives a grinding head to grind the concrete or steel structure surface, removing loose materials, laitance, rust, and old coatings, providing a clean base surface for subsequent repair work. A pneumatic spraying device 66 is used for spraying sealant or coating materials. Powered by compressed air, the pneumatic spraying device 66 atomizes the sealant or anti-corrosion coating material and sprays it onto the target surface to achieve surface sealing of cracks or anti-corrosion coating of steel structures.

[0079] With the combination of the above-mentioned repair tools and the tool switching function of the quick-change device 67, the end-of-line operation system 6 can complete a variety of repair operations such as grinding, sealing, gluing, filling, and spraying in the same work area, realizing integrated operation of defect detection and in-situ repair.

[0080] like Figure 9 As shown, the robot uses a segmented and directional correction fusion positioning method with encoder and NFC dual sensors to solve the problem of cumulative positioning error during long-distance track operation.

[0081] Existing track-guided robots typically use encoders for positioning. The encoder is mounted on the drive motor 21, and the robot's travel distance is calculated by recording the motor's revolutions. However, in actual operation, the encoder's positioning accuracy is affected by various factors, including track slope, turning radius, friction wheel slippage, and dust or water accumulation on the track surface. These factors cause the encoder's counting coefficient (i.e., the travel distance corresponding to each revolution) to drift. During long-distance operation, this coefficient drift leads to an increasing cumulative positioning error.

[0082] The fusion localization method used in this embodiment includes the following key points: First, before the robot operates, the maintenance track is divided into several homogeneous sections based on its slope, turning radius, and environmental conditions. A "homogeneous section" refers to a section of track with relatively consistent conditions, such as a straight, level slope section, an uphill section, or a curved section. NFC (Near Field Communication) positioning tags (IC cards) are placed at the endpoints of each section. NFC positioning tags are passive electronic tags that are embedded or affixed to fixed locations near the maintenance track; each NFC positioning tag stores the absolute coordinates of that location.

[0083] Secondly, an NFC reader is installed on the main beam truss 1 (i.e., on the gantry 11). When the robot passes through the end point of the section, the NFC reader reads the absolute position information in the NFC positioning mark to obtain the robot's current precise position.

[0084] Then, within each segment, the robot uses encoders for recursive positioning. However, unlike existing technologies, this method does not use fixed encoder coefficients; instead, it dynamically corrects the encoder coefficients based on the track segment and the direction of movement (forward or reverse). At each segment endpoint, the robot uses the newly acquired NFC absolute position to correct the cumulative encoder error and calculates the actual encoder coefficients for that segment. Since the track conditions (slope, curvature, etc.) are relatively consistent across each segment, using the corrected encoder coefficients for recursive positioning within that segment yields significantly higher accuracy than using uniform coefficients across the entire track. Furthermore, the shorter the segment and the more consistent the conditions, the higher the accuracy of the coefficient correction.

[0085] Finally, the encoder position and NFC position are fused using Kalman filtering. Kalman filtering is a commonly used data fusion algorithm that weights and fuses measurement data from two or more sensors according to their respective accuracies, yielding a more accurate estimate than any single sensor. In this method, when the robot is at the end of a segment, NFC provides a high-precision absolute position, while the encoder provides a continuous position estimate; when the robot is within a segment, the encoder provides a continuous position estimate, and NFC is temporarily unavailable. Kalman filtering automatically adjusts the weights based on the reliability of the two types of data, trusting NFC data more when it is available and encoder data more when NFC is unavailable, thus achieving continuous and accurate positioning throughout the entire track.

[0086] The advantages of this fusion positioning method are: instead of using fixed encoder coefficients to process the entire track, it dynamically identifies coefficients based on track sections and direction of movement and performs Kalman fusion, effectively reducing cumulative positioning errors on long and complex tracks. Accurate positioning information provides a reliable positional reference for recording defect locations, end-effector navigation, and post-repair inspection.

[0087] Furthermore, in this embodiment, the camera 51, laser ranging module 52, 3D guiding camera 63, collaborative arm 61, high-pressure blower 34, drive motor 21, telescopic drive motor 44, pneumatic grinding device 65, pneumatic spraying device 66, quick-change device 67, and each drive motor are all connected to the control system, and the control system is connected to the direct management platform to facilitate robot control and data recording.

[0088] Example 2 like Figure 10As shown, this embodiment, based on embodiment 1, provides a method for detecting and repairing defects in a detection and repair robot with end-effector vibration damping capability, including the following steps: S1. Task Planning and Positioning Before the operation begins, the operator or management system plans the task according to the bridge maintenance plan, pre-setting the path and target section for the robot to run along the maintenance track, and determining the inspection and photography angles and repair strategies within the target section. After the task planning information is input into the robot's control system, the control system controls the drive motor 21 to start, and the robot travels along the longitudinal maintenance track of the bridge to the target area. Upon reaching the target area, the control system controls the telescopic drive motor 44 to start, and the telescopic truss 4 extends laterally along the bridge to cover the target work area. Once the robot is in position, it enters the inspection and repair operation state.

[0089] During positioning, the robot uses an encoder and NFC-based fusion positioning method to obtain its precise position and compares it with the preset target position to ensure that the robot reaches the correct location. If the position deviation exceeds the allowable range, the control system will make fine adjustments until the robot reaches the target position.

[0090] S2. Disease Detection and Identification After the robot is in position, the mobile carrier 5 moves along the customized track 55, bringing the end-effector system 6 to the area to be inspected. Alternatively, the mobile truss 41 can be extended or retracted via a telescopic drive motor, bringing the end-effector system 6, located at the end of the mobile truss 41, to the area to be inspected. Upon reaching the area, the mobile carrier 5 uses a camera 51 and a laser ranging module 52 to acquire images and distance data of the bridge's outer surface. Simultaneously, a 3D guiding camera 63 acquires three-dimensional topographic data of the affected area (in actual operation, the 3D topographic data and related location of the affected area can also be acquired directly using only the 3D guiding camera 63). The control system analyzes and processes the acquired images and three-dimensional data to identify the location, shape, and type of defects on the bridge's outer surface. Defect types include, but are not limited to, concrete cracks, concrete spalling, steel main beam corrosion, and coating defects.

[0091] For concrete cracks, the control system extracts the crack's direction, width, depth, and morphological parameters. For concrete spalling, the control system measures the area, depth, and whether reinforcement is exposed in the spalled area. For corrosion or coating defects in steel main beams, the control system quantifies the area, location, and severity of corrosion or coating failure. These parameters will serve as the basis for subsequent classification and repair.

[0092] S3. Adsorption stability After the inspection is completed, the robot determines the area requiring repair. The control system activates the negative pressure adsorption device 3, and the lifting platform 31 drives the adsorption chamber 35 to approach the outer surface of the bridge. After the sealing skirt 36 is in contact with the outer surface of the bridge, the high-pressure blower 34 starts to extract air, creating a negative pressure inside the adsorption chamber 35. When the adsorption negative pressure reaches a set threshold (e.g., not less than 15 kPa) and stabilizes for 2 to 3 seconds, the control system confirms that the adsorption is stable and allows the end-of-line operation system 6 to enter the repair operation state.

[0093] Adsorption stabilization is a prerequisite for repair operations. Only after adsorption stabilization can the end-effector system 6 obtain sufficient end-effector stiffness and positioning stability to ensure the accuracy and quality of the repair operation. If the adsorption negative pressure fails to reach the set threshold or cannot be stabilized, the control system will issue an alarm, prompting the operator to check the cause (e.g., the sealing skirt 36 fails to properly adhere to the outer surface of the main beam, or there are large irregularities on the outer surface of the main beam). Adsorption stabilization will be performed again after the problem is resolved.

[0094] S4. Categorized Repair After adsorption stabilizes, the control system automatically selects the corresponding repair strategy based on the disease type and parameters obtained in stage S2. The collaborative arm 61 switches to the appropriate repair tool via the quick-change device 67 to perform in-situ repair work. The repair process for various types of diseases is described below.

[0095] 4.1 Concrete Crack Repair For concrete cracks, the robot processes them in stages based on crack width: Level 1: Cracks less than 0.15mm wide are classified as micro-cracks. The robot, via its collaborative arm 61, drives a pneumatic grinding device 65 to grind and clean an area of ​​at least 30mm on both sides of the crack, removing laitance, dust, and loose material to expose a solid concrete base. After grinding, the collaborative arm 61 switches to a pneumatic spraying device 66 via a quick-change device 67 to spray a low-viscosity, highly penetrating sealant onto the crack area. The sealant penetrates into the micro-cracks, sealing the crack surface and preventing moisture and harmful media from seeping into the concrete.

[0096] Level Two: Cracks with a width greater than or equal to 0.15 mm and less than or equal to 0.5 mm are classified as medium-width cracks. The robot first uses a pneumatic grinding device 65 to grind and clean the crack area, then performs low-pressure blowing (using compressed air to remove dust and debris generated during grinding), followed by sweeping. After the base surface treatment is completed, the collaborative arm 61 switches to the crack sealing and repair tool 64, using a low-pressure adhesive injection method of approximately 0.25 MPa for repair. Figure 8As shown, the crack sealing and repair tool 64 is pressed firmly against the concrete surface by the collaborating arm 61, and epoxy sealant is injected into the crack at low pressure through the epoxy sealant channel 643. The injection pressure is maintained until the sealant cures, ensuring that the epoxy sealant fully penetrates and fills the interior of the crack. After the sealant has cured, the crack sealing and repair tool 64 is withdrawn.

[0097] Level 3: Cracks wider than 0.5mm, or those that are active cracks (i.e., cracks still developing), seepage cracks (i.e., cracks with moisture seeping out), or cracks in critical load-bearing areas, are considered severe cracks. Repairing these types of cracks requires a comprehensive assessment of structural safety and the reliability of the repair plan. The robot does not repair itself but automatically marks the location of the damage and uploads it to the management platform, where it is then manually assessed and processed by professionals.

[0098] 4.2 Repair of concrete spalling For concrete spalling defects, the robot first determines whether the defects are repairable. If the spalled area does not expose the reinforcing bars (i.e., the internal reinforcing bars are not exposed) and there is no severe corrosion, and the spalling depth is no more than 30mm, the robot enters the automatic repair process. If the above conditions are not met (e.g., the reinforcing bars are exposed and there is severe corrosion, or the spalling depth is too great), the robot marks the defect and uploads it to the cloud platform or management platform through the control system, transferring it to manual processing.

[0099] After entering the automatic repair process, the robot generates a work area extending outward from the peeling edge by at least 30mm. Then, the substrate is cleaned: the collaborative arm 61 drives the pneumatic grinding device 65 to remove loose or non-dense parts of the peeling area layer by layer using a steel brush, followed by low-pressure blowing. Simultaneously, the camera 51 and the 3D guiding camera 63 visually inspect the substrate treatment quality and verify its roughness, confirming that the substrate treatment is qualified.

[0100] After the base surface treatment is deemed satisfactory, the robot performs layered filling. The collaborative arm 61 switches to the spalling repair tool 62, filling the spalled area with repair material (such as repair mortar) in layers. Each layer is 15 to 20 mm thick, with a compaction pressure of 0.15 to 0.25 MPa. The purpose of layered filling is to ensure the compactness of the repair material and avoid internal voids or shrinkage cracks caused by filling too thickly at once.

[0101] After the repair is completed, a leveling and re-inspection should be carried out. The repaired surface should be 1 to 2 mm higher than the original surface, and then the repair tool 62 should be used to scrape it flat to make the repaired surface transition smoothly with the original surface, and the final height difference should not exceed 3 mm.

[0102] 4.3 Repair of Rust / Coating Defects in Steel Main Beams For corrosion or coating defects on the main steel beam, the robot first scans and quantifies the corrosion or coating defects using camera 51, laser ranging module 52 and 3D guiding camera 63 to identify the area, location and grade of corrosion or coating defects.

[0103] The robot then determines whether the damage is repairable. If the damage is localized or involves localized corrosion and does not affect the structural load-bearing capacity, the robot enters the automatic repair process. If there is extensive failure, severe corrosion, or load-bearing risk, the robot switches to a manual assessment.

[0104] During automated repair, the robot first performs surface treatment. The collaborating arm 61 drives the pneumatic grinding device 65 to grind the damaged area down to the intact coating or metal substrate, removing rust and damaged coating. After grinding, the surface is cleaned by low-pressure blowing, and the surface treatment quality is checked by visual inspection to ensure it meets Sa2.5 or St3 standards (Sa2.5 and St3 are commonly used quality grade standards for steel structure surface treatment, corresponding to near-white cleaning and manual power tool cleaning quality requirements, respectively).

[0105] After the surface treatment quality is verified as qualified, the collaborative arm 61 switches to the pneumatic spraying device 66 via the quick-change device 67 to perform spraying. Low-pressure spray guns are used, and the spraying distance is controlled between 200 and 300 mm to ensure coating uniformity and adhesion. After spraying, a coating re-inspection is conducted, requiring the repaired area to be free of oil, dust, and old paint residue.

[0106] 4.4 Repair of Cracks in Steel Main Beams For cracks in the steel main beam, the robot first locates the crack tip and identifies the crack end and its direction of propagation. After location, the negative pressure adsorption device 3 maintains stable adsorption, and the collaborative arm 61 replaces the pneumatic spraying device 66 with an electric drill via the quick-change device 67. Under the visual guidance of the 3D guiding camera 63, drilling is performed to stop the crack at its tip. The purpose of drilling is to form a circular hole at the crack tip, eliminating stress concentration and preventing further crack propagation. After the crack-stopping operation is completed, the system records the drilling location and image evidence.

[0107] For concrete wide joints (crack width greater than 0.5mm), exposed rebar with severe corrosion, large-area coating failure, or situations posing structural risks, all will be moved to the manual handover entrance for assessment and handling by professionals.

[0108] S5. Quality Re-inspection and Closed-Loop After all types of defects have been repaired, they will proceed to the quality re-inspection stage. The re-inspection methods include high-magnification camera inspection (using camera 51 to capture high-resolution images of the repaired area), laser ranging (using laser ranging module 52 to measure the height difference between the repaired surface and the original surface), and visual template comparison (comparing the repaired images and three-dimensional data with standard templates).

[0109] If the re-inspection fails, for example, due to discontinuous sealing, grout leakage or nodules, excessive height difference in the repaired area, or oil or dust residue on the coating, the system returns to the corresponding process for rework. For example, if the crack sealing re-inspection fails, return to step S4.1 for re-insertion of adhesive; if the peeling repair re-inspection fails, return to step S4.2 for re-filling and leveling.

[0110] If the re-inspection is passed, the repair work is completed. The system generates a repair file, recording the defect number, coordinates (provided by the encoder and NFC fusion positioning system), material batch, operation parameters, before and after images, and re-inspection results. The relevant data is uploaded to the cloud or management platform to form a complete and traceable repair file, which is conducive to the digital and standardized management of bridge maintenance.

[0111] If the repair task for the current target segment is completed, but there is still another segment to be worked on, the robot returns to step S1 and continues to travel along the track to the next target segment for work. If all segments are completed, the repair task ends.

[0112] After the adsorption stabilizes in step S3, the robot enters the repair operation state. During the repair operation, the negative pressure adsorption device 3 does not work continuously at a fixed pressure, but dynamically adjusts according to the real-time monitored end state and environmental parameters to achieve a continuous end vibration suppression effect.

[0113] Specifically, during the repair operation, detection tools such as camera 51, laser ranging module 52, and 3D guiding camera 63 monitor the end displacement in real time. End displacement refers to the amount of displacement of the tool of the end-operation system 6 relative to the outer surface of the main beam. When the end displacement exceeds a set threshold (e.g., 0.5mm), it indicates that the current adsorption force is insufficient to resist external disturbances (which may be bridge vibration, wind load, or the reaction force of the repair tool). At this time, the control system will increase the pumping power of the high-pressure fan 34 to increase the adsorption negative pressure, thereby increasing the adsorption force and suppressing the end displacement within the allowable range.

[0114] Meanwhile, the control system also monitors environmental parameters, including wind speed and bridge vibration acceleration. When the wind speed exceeds a set threshold (e.g., 5 m / s) or the bridge vibration acceleration exceeds a set threshold (e.g., 0.3 m / s²), it indicates an increase in external disturbance. Even if the current end displacement has not exceeded the limit, the control system will preemptively increase the adsorption negative pressure to maintain end stability.

[0115] Furthermore, during the tool switching process—that is, when the quick-change device 67 disassembles the old tool and installs the new tool—the negative pressure adsorption device 3 maintains an uninterrupted adsorption state. This ensures that the end position remains consistent before and after tool switching, preventing positioning deviations caused by tool switching from affecting the accuracy of subsequent repair operations.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A detection and repair robot with end-effector vibration damping capability, characterized in that, include: The track and walking structure is used to suspend and walk on the maintenance track at the bottom or side of the bridge, driving the robot to move longitudinally along the bridge. The main beam truss is connected to the hanging rail and walking structure, serving as the robot's load-bearing skeleton. Telescopic trusses are installed on both sides of the main beam truss and can be extended or retracted along the transverse direction of the bridge to cover the bottom, sides, flange bottom surface and cantilever area of ​​bridges with different beam widths. The negative pressure adsorption device is installed at the end of the telescopic truss to form a negative pressure adsorption connection with the outer surface of the bridge during the inspection or repair process, so as to improve the equivalent stiffness of the end and suppress the impact of bridge vibration on the end operation. The end-of-line operation system, located at the end of the telescopic truss, includes a cooperating arm, a quick-change device connected to the cooperating arm, and multiple inspection and repair tools arranged on the quick-change device. The cooperating arm is used to drive the quick-change device and repair tools to the working area at the bottom of the bridge beam, the side of the beam, and the bottom of the flange. The quick-change device is used to switch between different inspection and repair tools to achieve integrated operation of defect detection and in-situ repair.

2. The robot according to claim 1, characterized in that, The rail and traveling structure includes a drive motor, rail drive wheel, anti-fall rod, suspension load-bearing base, guide wheel, and rail and traveling frame; The rail drive wheel is rotatably installed in the rail and the walking frame, and suspended from the maintenance track at the bottom or side of the bridge; the drive motor is installed on the outside of the rail and the walking frame, and outputs driving force to the rail drive wheel to drive the robot to move longitudinally along the bridge; the guide wheel is rotatably installed in the rail and the walking frame, and is set at both ends of the robot's walking direction to guide the robot to travel along the maintenance track and reduce the risk of getting stuck. The fall arrestor is installed in the rail and traveling frame and positioned above the rail drive wheel to provide fall protection. The suspended load-bearing base is connected to the bottom of the rail and traveling frame via a load-bearing connector to connect the main beam truss.

3. The robot according to claim 1, characterized in that, The negative pressure adsorption device includes a lifting platform, a universal support platform, a high-pressure fan, an adsorption chamber, and a sealing skirt. The lifting platform is installed at the end of the telescopic truss. The adsorption chamber is connected to the lifting platform through the universal support platform. The sealing skirt is arranged on the outer circumference of the adsorption chamber. The high-pressure fan is arranged on the adsorption chamber for drawing air out of the adsorption chamber. The lifting platform drives the adsorption chamber to approach the outer surface of the main beam. The universal support platform enables the adsorption chamber to adapt to the local angle changes of the outer surface of the main beam. After the sealing skirt is in contact with the outer surface of the bridge, the high-pressure fan creates a negative pressure in the adsorption chamber. When the adsorption negative pressure reaches a set threshold and stabilizes, the end operation system performs detection or repair actions.

4. The robot according to claim 1, characterized in that, The telescopic truss includes a movable truss, a fixed truss, a rack, a telescopic drive motor, and a guide limiting plate. The fixed truss is fixed on the main beam truss and arranged parallel to the beam side of the bridge. The movable truss is slidably arranged in the fixed truss. The guide limiting plate is installed in the fixed truss and located on both sides of the movable truss to constrain the movement direction of the movable truss and limit its movement range. A rack is provided at the bottom of the movable truss, and the telescopic drive motor is provided in the fixed truss. The telescopic drive motor drives the movable truss to expand or contract laterally along the bridge through the rack, and the movable trusses at both ends of the main beam truss expand or contract synchronously, so that the robot's center of gravity is kept in the middle of the maintenance track, thereby reducing the lateral additional load on the maintenance track.

5. The robot according to claim 1, characterized in that, The detection tool of the end-of-line operation system includes a 3D guided camera, which is used to acquire the three-dimensional shape of the diseased area and guide the tool's posture; the repair tool includes one or more of the following: crack sealing repair tool, peeling repair tool, pneumatic grinding device, and pneumatic spraying device. The crack sealing and repair tool includes a smooth steel plate connected to the quick-change device and epoxy sealant channels formed by several staggered sealing rubbers on the side of the smooth steel plate away from the quick-change device.

6. The robot according to claim 1, characterized in that, It also includes a mobile vehicle equipped with an end-effector system, which is set on a customized track on the main beam truss. The mobile vehicle includes a vehicle body, a camera mounted on the vehicle body, a laser ranging module, lateral limiting wheels, vertical limiting wheels, and drive wheels. The camera and laser ranging module provide a data basis for identifying the location of defects, adjusting the attitude of the end-effector system, and re-inspecting the repair quality. The lateral and vertical limiting wheels limit the deviation of the mobile vehicle on the customized track.

7. The robot according to claim 2, characterized in that, The method of segmented and directional correction and fusion positioning using an encoder and NFC dual sensors linked with the drive motor is adopted: the maintenance track is divided into several homogeneous sections according to the slope, turning radius and environmental conditions of the maintenance track, NFC positioning marks are set at the end points of the sections, and an NFC reading device for reading the NFC positioning marks is provided on the main beam truss. The absolute position is corrected using NFC positioning information at the end of the section, and recursive positioning is performed using the encoder coefficients after direction correction within the section. The encoder position and NFC position are fused by Kalman filtering to reduce the cumulative positioning error during long-distance track operation.

8. A method for operating a robot based on any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Task planning and positioning: Pre-set the path and target section of the robot along the maintenance track, control the robot to travel along the longitudinal track of the bridge to the target area, and deploy the telescopic truss to cover the target work area; S2. Defect Detection and Identification: Utilize detection tools to obtain information on the location, morphology, and type of defects on the bridge's outer surface; S3. Adsorption stabilization: After starting the negative pressure adsorption device and forming a negative pressure adsorption connection with the outer surface of the bridge, the repair work begins; S4. Categorized Repair: Select the corresponding repair strategy according to the type of disease and parameters. The collaborative arm drives the corresponding repair tools to perform in-situ repair after switching through the quick-change device. S5. Quality Re-inspection and Closed Loop: After the repair is completed, the repaired area is re-inspected using testing tools. If the re-inspection fails, return to step S4 for rework. If the re-inspection passes, the repair work is completed.

9. The method according to claim 8, characterized in that, The classification repair in step S4 includes: For concrete cracks, treatment is categorized according to crack width: When the crack width is less than 0.15mm, the crack sides are ground and cleaned, and then a sealant is sprayed to seal the surface; when the crack width is between 0.15mm and 0.5mm, the crack is ground, blown, and cleaned, and then repaired using low-pressure injection, maintaining pressure until the sealant cures; when the crack width is greater than 0.5mm, or is a crack in an active joint, a seepage joint, or a crack in a critical stress area, the location of the defect is marked and uploaded to the platform for manual evaluation and treatment. For concrete spalling, if the spalled area does not expose the reinforcement and the depth is no more than 30mm, the base surface should be cleaned and the spalled area should be filled in layers after extending the work area outward by no less than 30mm; otherwise, it should be marked and handled manually. For steel main beams with rust or coating defects, if the failure is localized and does not affect the structural bearing capacity, the coating or metal substrate should be ground down to a good condition before spraying repair; otherwise, manual assessment will be required.

10. The method according to claim 8, characterized in that, After the adsorption stabilizes in step S3, the end displacement is monitored in real time by the detection tool during the repair operation. If the end displacement exceeds the set threshold, the negative pressure adsorption pressure is adjusted. If the wind speed or vibration acceleration exceeds the set threshold, the negative pressure of adsorption will be increased, and the negative pressure adsorption device will remain in adsorption state during the switching of repair tools.

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