Dam concrete surface detection and repair underwater robot and detection and repair method

Abstract

This invention relates to an underwater robot and method for inspecting and repairing concrete surfaces of dams. The robot includes a robot body module and a surface treatment module. The robot body module includes a power mechanism for driving the robot to achieve multi-degree-of-freedom movement underwater, a motion control mechanism for recording the robot's entry point coordinates and estimating its absolute coordinates in real time underwater, and a detection mechanism for detecting defects on the dam concrete surface and determining their locations. The surface treatment module includes a tool assembly for performing repair work within the work area, a position adjustment assembly for projecting the outline of the work area onto the dam surface and adjusting the robot's position accordingly, and an adsorption assembly for forming negative pressure adsorption with the dam surface to fix the robot in the work position. This invention enables underwater in-situ detection, precise positioning, and repair of cracks on the dam concrete surface without lowering the reservoir water level.

Description

Technical Field

[0001] This invention belongs to the field of underwater inspection and underwater repair technology, and particularly relates to an underwater robot and inspection and repair method for the inspection and repair of concrete surfaces of dams. Background Technology

[0002] Dams play a vital role in national production and economic activities. Currently, my country has over 100,000 dams, primarily concrete dams. Due to the long-term operation of dams, the structures of hydraulic engineering structures age annually, and the surface concrete of the dam body is gradually eroded by water flow. Coupled with the impact of floods during the rainy season, extreme weather, and natural disasters such as earthquakes, the safety of dam operation is becoming increasingly prominent. During routine inspections, instances of dam damage such as leakage, concrete cracks and missing parts, erosion, and craters are frequently observed. Among these, surface cracks are the most visible and dangerous manifestation. Once cracks appear in a dam, if they are not treated promptly, they are highly likely to continue to expand and spread, seriously affecting the safe and stable operation and long-term benefits of the dam.

[0003] For concrete cracks on the dam surface, surface anti-seepage repair technology is widely used both domestically and internationally. Specific methods include backfilling, chemical grouting, applying cement-based penetrating crystallizing materials, and crack closure. Since the cracks are usually below the water surface, in the past, repair work typically required draining the reservoir water level below the cracks before treatment could proceed. This resulted in two problems: firstly, it delayed the repair time; secondly, it reduced the water storage capacity, causing serious waste of water resources and affecting the normal operation of the dam for power generation, irrigation, and other scheduling purposes.

[0004] Regarding the seepage prevention and repair of underwater dam concrete surfaces, existing technologies generally suffer from the drawback of excessively long time cycles from the detection of seepage to the completion of repairs. This forces dams to operate at low water levels for extended periods, and in extreme cases, the reservoir water level may not drop below the damaged area in time, leading to gradually increasing seepage and compromising dam safety. In recent years, underwater robotics and underwater construction technologies have developed rapidly, leading to the proposal of methods for directly repairing dam cracks underwater. Various underwater repair solutions based on specialized equipment or robotic platforms have emerged.

[0005] However, the existing underwater repair technologies generally suffer from the following drawbacks: First, the detection and repair functions are separated, requiring the robot to repeatedly surface to change tools, significantly reducing operational efficiency; second, the degree of automation is insufficient, with excessive reliance on manual intervention in crack identification, location, and repair processes; third, the repair tools are limited, making it impossible to complete the entire process from surface treatment to grouting repair; fourth, there is a lack of effective underwater wall adsorption and stabilization mechanisms, making it difficult to ensure repair accuracy under water flow disturbances; and fifth, the ability to identify small cracks is insufficient. Therefore, there is an urgent need for an underwater robot that integrates detection, location, and in-situ repair functions to meet the practical engineering needs of dam safety maintenance. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an underwater robot and a method for detecting and repairing cracks on the surface of dam concrete. This robot can detect, locate, and repair cracks on the surface of dam concrete underwater. Compared with existing technologies, it has the advantages of high automation, no need for repeated descent, and the ability to complete the entire repair process in one go. This solves the technical problems of existing underwater robots, such as separation of detection and repair functions, low automation, limited repair tools, lack of stable adsorption, and difficulty in identifying small cracks.

[0007] This invention provides an underwater robot for inspecting and repairing the concrete surface of dams, comprising a robot body module and a surface treatment module, wherein... The robot body module includes a power mechanism for driving the robot to achieve multi-degree-of-freedom motion underwater, a motion control mechanism for recording the robot's entry point coordinates and estimating the robot's absolute coordinates in real time underwater, and a detection mechanism for detecting defects on the concrete surface of the dam and determining the location of the defects. The surface treatment module includes a work tool assembly for performing repair work within the work area, a position adjustment assembly for projecting the outline of the work area onto the dam surface and adjusting the robot's position accordingly, and an adsorption assembly for forming a negative pressure adsorption with the dam surface to fix the robot in the work position.

[0008] In some embodiments, the robot body module further includes a frame body, on both the upper and lower surfaces of which buoyancy material is disposed, and the volume of the buoyancy material on the lower surface is greater than the volume of the buoyancy material on the upper surface.

[0009] In some embodiments, the power mechanism includes The electric pump is housed within the frame body; Multiple vertical thrusters are symmetrically arranged on the top of the frame body. The vertical thrusters are electrically connected to the motor pump, and the vertical thrusters control the robot's heave, pitch and roll motion under the drive of the motor pump. Multiple horizontal thrusters are installed inside the frame body and are evenly arranged along the circumference of the frame body. The horizontal thrusters are electrically connected to the motor pump, and the horizontal thrusters control the robot's forward and backward movement, left and right movement and yaw turning under the drive of the motor pump.

[0010] In some embodiments, the motion control mechanism includes An embedded control system is located inside the frame body; A waterproof GPS unit is installed on the top of the frame body and electrically connected to the embedded control system. The waterproof GPS unit is used to record the absolute coordinates of the water entry point on the water surface. The pose sensing device is installed inside the frame body and electrically connected to the embedded control system. The pose sensing device is used to estimate the current absolute coordinates of the underwater robot in real time based on the absolute coordinates of the water entry point recorded by the waterproof GPS and the pose inference method.

[0011] In some embodiments, the pose sensing device includes Speed ​​sensors are used to measure the movement speed of robots; An attitude measuring instrument is used to measure the attitude and angular velocity of a robot. A Doppler velocimeter is used to measure the ground velocity of a robot relative to the underwater surface.

[0012] In some embodiments, the detection mechanism includes Acoustic imaging equipment, located at the front of the frame body, is used to continuously scan the surface of the dam to detect suspected defects and calculate the relative position of the suspected defects to the robot. The optical imaging equipment, located at the front of the frame body, includes an underwater camera for environmental observation and operational condition acquisition, and a rangefinder for measuring the distance between the underwater camera and the dam surface to correct distortion of the images acquired by the underwater camera.

[0013] In some embodiments, the surface treatment module further includes a lifting articulated arm mechanism for raising and lowering the working tool assembly and adjusting its position in a two-dimensional plane. The lifting articulated arm mechanism includes... Vertical lifting guide rails are installed at the bottom of the frame body; Two guide slide rods are set parallel to the vertical lifting guide rail; The lifting sliding platform is mounted across two guide rails and can slide up and down along the guide rails; The main articulated arm connects to the lifting sliding platform at one end and to the work tool assembly at the other end.

[0014] In some embodiments, the position adjustment component includes A laser projector, located on the side of the vertical lifting guide rail, is used to project the outline of the working area onto the surface of the dam. The projection acquisition camera, located on the side of the vertical lifting guide rail, is used to transmit the projected image to the computer so that the operator can adjust the robot's position based on the projected position and the crack image.

[0015] In some embodiments, the adsorption component includes The suction base plate is located at the end of the vertical lifting guide rail away from the frame body, and the suction base plate is equipped with a suction port. The water absorption chamber is located inside the frame body and is connected to the suction interface through pipes.

[0016] In another aspect, the present invention provides a method for inspecting and repairing the concrete surface of a dam, using the underwater robot for inspecting and repairing the concrete surface of a dam, comprising the following steps: S1. Control the robot to approach the dam wall. The laser projector of the position adjustment component projects the working position on the dam surface. Adjust the robot position according to the projected image and crack image information. S2. The robot is controlled to achieve stable adhesion to the surface of the dam. S3. If the robot's position meets the repair requirements, start the repair; otherwise, separate from the dam surface and repeat S1. S4. Plan the cutting closed-loop area according to the direction, size and shape of the crack, and use the underwater cutting tool of the working tool component to cut along the closed-loop area; S5. After the underwater cutting tool is reset, the underwater drilling tool of the working tool assembly is activated to drill in the closed loop area to form a repair channel. S6. After the underwater drilling tool is reset, the underwater grinding tool of the working tool component will grind the uneven area in the closed loop to make it smooth. S7. After the underwater grinding tool is reset, start the underwater flushing tool of the working tool component to clean the residue in the closed loop area. Determine whether to return to the corresponding steps in S4, S5, and S6 based on the cleaning effect. S8. After confirming that the area has been cleaned up to standard, inject repair material into the repair channel to complete the crack filling and repair and record the repair location data.

[0017] Compared with existing technologies, the beneficial effects of this invention are as follows: The underwater robot for inspecting and repairing dam concrete surfaces can perform in-situ underwater inspection, precise positioning, and repair of cracks on the dam concrete surface without lowering the reservoir water level. It boasts technical advantages such as integrated inspection and repair, high automation, no need for repeated descent, and the ability to complete the entire repair process in one go. This avoids water loss, enables timely crack treatment, effectively reduces dam maintenance costs and operational risks, and significantly improves operational efficiency. This invention uses a motion control mechanism to record the robot's entry point coordinates and estimate its absolute coordinates underwater in real time. The inspection mechanism detects defects on the dam concrete surface and determines their locations. The position adjustment component projects the outline of the work area onto the dam surface and adjusts the robot's position accordingly. This coordinated operation achieves fully automated or semi-automated operation from inspection to repair. The power mechanism drives the robot to achieve multi-degree-of-freedom movement underwater. The adsorption component forms a negative pressure adsorption with the dam surface to fix the robot in the work position, ensuring the underwater robot for inspecting and repairing dam concrete surfaces remains stably attached to the dam surface even under water flow disturbance conditions, ensuring the accuracy of the repair operation. The tooling components can be flexibly combined with four operations—cutting, drilling, grinding, and rinsing—to complete the repair process, depending on the condition of the crack. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the system module frame structure of the underwater robot for inspecting and repairing the concrete surface of a dam, according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the control components of an underwater robot for inspecting and repairing the concrete surface of a dam, according to an embodiment of the present invention. Figure 3 This is a flowchart illustrating the operation of a method for repairing concrete cracks on the surface of a dam, according to an embodiment of the present invention.

[0019] In the diagram: 1. Underwater robot for inspecting and repairing concrete surfaces of dams; 100. Robot body module; 110. Frame body; 111. Upper frame; 112. Side frame; 113. Lower frame; 120. Power mechanism; 121. Motor pump; 122. Vertical thruster; 123. Horizontal thruster; 130. Motion control mechanism; 131. Embedded control system; 132. Waterproof GPS; 133. Pose perception sensor; 1331. Velocity sensor; 1332. Attitude measuring instrument; 1333. Doppler velocimeter; 140. Detection mechanism; 141. Acoustic imaging equipment; 142. Optical imaging equipment; 1421. Underwater camera; 1422. Rangefinder; 150. Pressure-resistant control cabin; 200. Surface treatment module; 210. Lifting articulated arm mechanism; 211. Vertical lifting guide rail; 212. Guide slide bar; 213. Lifting sliding platform; 214. Main articulated arm; 215. Main arm articulation pin; 216. Main arm rotation pivot; 220. Working tool assembly; 230. Position adjustment assembly; 231. Laser projector; 232. Projection acquisition camera; 240. Adsorption assembly; 241. Adsorption base plate; 242. Piping; 2. Dam. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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, they should not be construed as limitations on this invention.

[0022] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Reference Appendix Figure 1 As shown, this embodiment of the invention provides an underwater robot for the inspection and repair of concrete surfaces in dams. It consists of two parts: a robot body module 100 and a surface treatment module 200. The two parts are detachably connected through standard mechanical and electrical interfaces. The surface treatment module 200 is installed below the robot body module 100 for easy on-site assembly and disassembly.

[0025] Reference Appendix Figure 1 As shown, the robot body module 100 includes a frame body 110, with buoyancy material arranged on both the upper and lower surfaces of the frame body 110. The volume of the buoyancy material on the lower surface is larger than that on the upper surface, ensuring that the center of buoyancy of the robot body module 100 is below its center of gravity. This guarantees good inherent stability of the robot in water and prevents it from tipping over in a powerless state. When the surface treatment tool is installed below the robot body module 100, the center of gravity and center of buoyancy of the entire robot are brought as close as possible, further improving the system's posture stability and ensuring motion accuracy during inspection and repair operations. Preferably, the frame body 110 includes an upper frame 111, side frames 112, and a lower frame 113, with a panel mounting bracket disposed between the upper frame 111 and the lower frame 113.

[0026] Reference Appendix Figure 1 and attached Figure 2 As shown, the robot body module 100 includes a power mechanism 120 for driving the robot to perform full six-degree-of-freedom motion underwater, ensuring precise maneuverability in complex environments. The power mechanism 120 further includes a motor pump 121, disposed within the frame body 110; four vertical thrusters 122, symmetrically arranged at the four corners of the upper frame 111, electrically connected to the motor pump 121, which control the robot's heave, pitch, and roll motion under the drive of the motor pump 121; and four horizontal thrusters 123, symmetrically arranged within the frame body 110, electrically connected to the motor pump 121, which control the robot's horizontal motion, including forward / backward and left / right movements, and yaw steering under the drive of the motor pump 121. During operation, the electric motor pump 121 drives eight thrusters to work in coordination, enabling precise maneuvering control of the underwater robot in six degrees of freedom: underwater heave, pitch, roll, forward / backward, left / right movement, and yaw.

[0027] Reference Appendix Figure 1 and attached Figure 2As shown, the robot body module 100 also includes a motion control mechanism 130, installed inside the pressure-resistant control chamber 150 located within the frame body 110. This mechanism records the absolute coordinates of the entry point at the water surface and switches to pose estimation mode underwater to estimate the robot's current absolute coordinates in real time, providing a coordinate reference for recording the absolute position of the crack. The pressure-resistant control chamber 150 is preferably a cylindrical pressure tank to protect internal electronic components and other equipment. The motion control mechanism 130 further includes an embedded control system 131 mounted on a panel mounting bracket; a waterproof GPS 132 mounted on the top of the upper frame 111 and connected to the embedded control system 131, the waterproof GPS 132 being used to record the absolute coordinates of the entry point on the water surface, including latitude, longitude, and elevation information; a pose perception sensor 133, used to estimate the robot's current absolute coordinates in real time using a pose estimation method based on the absolute coordinates of the entry point recorded by the waterproof GPS 132, the pose perception sensor 133 further including a speed sensor 1331 mounted on the outside of the pressure-resistant control chamber 150, used to measure the robot's movement speed; an attitude measuring instrument 1332 (IMU) mounted on the outside of the pressure-resistant control chamber 150, used to measure the robot's attitude and angular velocity; and a Doppler velocity meter 1333 (DVL) mounted on the side frame 112, used to measure the robot's ground velocity relative to the bottom of the water. During operation, the absolute coordinates of the entry point are first recorded on the water surface using a waterproof GPS 132. Once the robot is fully submerged, the system switches to pose estimation mode because GPS signals cannot penetrate the water. Using the GPS coordinates of the entry point as the initial value, the system integrates velocity information measured by DVL and attitude and angular velocity data measured by IMU. Through pose estimation algorithms such as extended Kalman filtering, the system achieves real-time estimation of the robot's current absolute coordinates, providing a coordinate reference for recording the absolute position of the crack.

[0028] Reference Appendix Figure 1 and attached Figure 2As shown, the robot body module 100 also includes a detection mechanism 140 for detecting defects on the concrete surface of the dam and determining their locations. The detection mechanism 140 includes an acoustic imaging device 141 and an optical imaging device 142. The acoustic imaging device 141 is mounted on the upper part of the robot body module 100 and is used to continuously scan a large area of ​​the dam surface 2 in front of the robot to detect suspected defects and calculate the relative position of the suspected defects to the robot. It has the advantages of low underwater propagation loss and is unaffected by water turbidity, enabling continuous scanning of a large area of ​​the dam surface in front of the robot and rapid detection of defects on a large scale of the dam concrete surface. Defects detected by sonar are defined as suspected defects, and the relative position of the suspected defects to the robot is calculated from the sonar images, providing coordinates for the robot to navigate to the suspected defect point. The acoustic imaging device 141 includes one or more underwater sonar devices such as multibeam sonar, three-dimensional imaging sonar, and synthetic aperture sonar. An optical imaging device 142 is installed at the front of the upper frame 111. After a suspected defect is detected, the robot navigates to the suspected defect according to the relative position calculated by the sonar, and the power mechanism 120 maintains the stability of the robot's posture. The optical imaging device 142 includes two underwater cameras 1421 and a rangefinder 1422. The underwater cameras 1421 have the ability to observe the working surface and the lateral space, and further include a forward-facing camera for observing the environment in front of the robot and a lateral camera for observing the lateral space and fully capturing the working conditions of the working tools. An adjustable auxiliary lighting device is installed next to the underwater cameras 1421 for illumination. The rangefinder 1422 is used to detect the distance between the underwater cameras 1421 and the surface of the dam 2. The measured distance value is used to correct the geometric distortion of the images acquired by the underwater cameras 1421 and improve the image analysis accuracy. The rangefinder 1422 can be configured as a laser rangefinder, an ultrasonic rangefinder or other types of distance measuring devices. A laser rangefinder is preferred, with a ranging accuracy of ±1mm and an effective range of 0.1~50m.

[0029] Upon detecting a suspected defect, the robot navigates to the defect and maintains stable attitude via its propulsion system. It then observes images of the suspected defect using an underwater camera 1421, adjusting the output brightness of the underwater auxiliary lighting equipment based on underwater lighting conditions to obtain clear underwater images. Image recognition algorithms are used to analyze and process the images to determine if the suspected defect is a crack. For confirmed cracks, the robot further measures the crack's length, width, and direction based on the images. Using the robot's absolute position estimated by the motion control mechanism 130, and the relative positions of the crack and the robot measured by the underwater camera 1421 and rangefinder 1422, the robot performs a comprehensive calculation of the crack's absolute position and geometric dimensions. This data is then stored and recorded to create an electronic map of the underwater crack distribution in dam 2, providing data for subsequent maintenance and repair decisions.

[0030] Reference Appendix Figure 1 As shown, the surface treatment module 200 of the present invention is installed below the robot body module 100 and is mainly responsible for the in-situ surface treatment and repair of cracks on the concrete surface of the dam. The surface treatment module 200 includes a lifting articulated arm mechanism 210, which further includes a vertical lifting guide rail 211 installed at the bottom of the lower frame 113; two guide rails 212 arranged parallel to the vertical lifting guide rail 211; a lifting sliding platform 213 mounted across the two guide rails 212 and capable of sliding up and down along the guide rails 212; a main articulated arm 214, one end of which is connected to the lifting sliding platform 213 via a main arm articulation pin 215 and a main arm rotation pivot 216, and the other end of which is connected to the working tool assembly 220 via a tool fixing module; the working tool assembly 220 is lifted and lowered and its position adjusted in a two-dimensional plane via the lifting articulated arm mechanism 210, and is used to perform repair work within the working area. The working tool assembly 220 includes underwater cutting tools, underwater rinsing tools, underwater grinding tools, and underwater drilling tools, each of which can perform independent working functions along the working plane.

[0031] During operation, the guide slide 212 moves along the vertical lifting guide rail 211 in a vertical direction parallel to the surface of the dam 2. According to the task, the lifting sliding platform 213 is first controlled to move to the target position, and the working tool assembly 220 installed on the lifting sliding platform 213 is controlled to move along the guide slide 212 in a horizontal direction, moving the working tool assembly 220 to the starting point of the operation, achieving precise positioning in a two-dimensional plane. The repair operation range is the envelope of all positions that the working tool assembly 220 can reach without collision when moving along the vertical lifting guide rail 211 and performing operations, that is, the maximum area that the underwater robot can cover in a single repair operation. When the actual crack length is greater than the range of a single operation, the repair can be completed block by block. A certain overlap range must be maintained between adjacent repair blocks to ensure the continuity and integrity of the repair and avoid missing areas.

[0032] Reference Appendix Figure 1 As shown, the surface treatment module 200 also includes a position adjustment component 230, used to project the outline of the work area onto the surface of the dam 2 and adjust the robot position accordingly. The position adjustment component 230 further includes a laser projector 231, disposed on the side of the vertical lifting guide rail 211. The laser projector 231 projects the outline of the work area onto the surface of the dam 2 by the operator specifying the repair shape (rectangle, polygon, etc.). A projection acquisition camera 232, disposed on the side of the vertical lifting guide rail 211, is located on the same side as the laser projector 231 and is used to transmit the projected image to a computer so that the operator can adjust the robot position according to the projected position and the crack image to ensure that the crack is completely within the repair work area.

[0033] The surface treatment module 200 also includes an adsorption assembly 240 for reliably fixing the robot to the bottom of the dam 2, enabling the robot to perform mobile operations on the underwater surface. The adsorption assembly 240 further includes an adsorption base plate 241, located at the end of the vertical lifting guide rail 211 away from the frame body 110. Preferably, the adsorption base plate 241 is made of water-resistant rubber material, providing good sealing performance. A water-absorbing chamber is located inside the frame body 110 and connected to a suction port via a pipe 242, which is equipped with a normally closed valve. Preferably, the water-absorbing chamber contains an electric telescopic rod. The fixed end of the electric telescopic rod is connected to the inner wall of the water-absorbing chamber, and the free end is connected to a piston. A sealed cavity is formed inside the water-absorbing chamber through the piston. The electric telescopic rod drives the piston to move, drawing water from the space between the adsorption base plate 241 and the bottom of the dam 2 into the water-absorbing chamber, creating a negative pressure at the adsorption base plate 241, thus adsorbing the underwater robot onto the surface of the dam 2. During operation, after the adsorption base plate 241 contacts the bottom surface of the dam 2, a closed water-bearing space is formed. By driving the electric telescopic rod in the water suction chamber to move, the piston moves and the water in the adsorption base plate 241 is drawn into the water suction chamber through the suction interface and pipe 242, so that the closed space forms a negative pressure adsorption force, thereby reliably fixing the robot to the bottom of the dam 2, realizing the robot's mobile operation along the bottom surface. At this time, the thrust of the vertical thruster 122 can be gradually reduced, and the robot's position at the bottom of the dam 2 is maintained by the adsorption force of the adsorption base plate 241. When the robot's working position needs to be moved, the negative pressure is eliminated by draining water, and the power mechanism 120 separates the robot from the adsorption surface, and the robot can float to the next working position.

[0034] The present invention adopts the above-mentioned adsorption component 240 design, which greatly expands the working space of the robot, so that the robot can perform operations without being fixedly attached to the hanging wall. At the same time, it provides a reliable reference benchmark for repairing underwater robots with curved, arc or irregular surfaces.

[0035] The complete workflow and rework determination mechanism of the dam concrete surface inspection and repair method of this invention are as follows: Figure 3 As shown, the specific steps include: Step S1: Maneuver the underwater robot 1 for inspecting and repairing the concrete surface of the dam to approach the wall of the dam 2. The laser projector 231 projects the work position on the dam surface. Adjust the position of the robot according to the projected image and crack information to ensure that the crack is within the repair work area. Step S2: Slowly move the robot close to the surface of the dam 2 until the adsorption base plate 241 is in contact with the surface of the dam 2, so that the closed space of the adsorption base plate 241 forms a negative pressure adsorption force; verify that the adsorption force meets the operation requirements and the robot and the surface of the dam 2 form a stable relative position. Step S3: If the robot's position meets the repair accuracy requirements, begin the repair process; otherwise, separate the robot from the dam surface and repeat step S1. Step S4: Plan the cutting closed-loop area according to the direction, size and shape of the crack, and use an underwater cutting tool to cut along the path of the closed-loop area to remove the loose and weathered concrete around the crack. Step S5: After the underwater cutting tool is reset, the underwater drilling tool is started to drill in the closed loop area to form a rough repair channel. Step S6: After the underwater drilling tool is reset, start the underwater grinding tool to grind the uneven areas in the closed loop area to make them smooth. Step S7: After the underwater grinding tool is reset, start the underwater flushing tool and use high-pressure water jet to clean the concrete residue and debris in the closed loop area; decide whether to return to step S4, S5 or S6 based on the cleaning effect, and circulate the process until the grouting conditions are met. Step S8: After the area cleanup is confirmed to be up to standard by the underwater camera 1421, underwater repair material is injected into the repair channel to complete the crack filling and repair, and data such as the repair location coordinates and crack geometric parameters are recorded. The underwater repair material can be underwater epoxy resin or cement-based penetrating crystallizing material.

[0036] Example 1 This embodiment provides an underwater robot for inspecting and repairing the concrete surface of dams, with specific parameter configurations including... (1) The total weight of the robot is about 200 kg, and the buoyancy in the water is adjusted by the volume of the buoyancy material by about ±5 kg; the robot body module dimensions are: length × width × height = 1500 mm × 1200 mm × 600 mm; (2) Power mechanism: It is equipped with four vertical thrusters with a power of 400W and four horizontal thrusters with a power of 300W. The maximum forward speed of the vertical thrusters and horizontal thrusters is 2.5 knots, the maximum lateral speed is 1.5 knots, the maximum lifting speed is 1.0 knots, the maximum operating water depth is 80m, and the protection level is IP68. (3) Acoustic imaging equipment: equipped with multi-beam imaging sonar with a frequency of 900kHz, a resolution of 3mm, and a detection range of 0.5~10m; three-dimensional imaging sonar with a frequency of 1.8MHz, a point cloud accuracy of 5mm, and a scanning angle of 120°×30°, which can clearly identify concrete surface cracks larger than 0.2mm. (4) Optical imaging equipment: equipped with a 4K underwater camera with a resolution of 3840×2160 pixels and a frame rate of 30fps; a laser rangefinder with an accuracy of ±1mm and a range of 0.1~20m; and an LED underwater light with a total power of 600W, a color temperature of 5500K, and an illuminance of ≥5000lux@1m. (5) Motion control mechanism: waterproof GPS (accuracy ±2m, used for water surface positioning), DVL (speed accuracy 0.2%, range 0~80m), IMU (angle accuracy 0.05°), combined positioning accuracy: horizontal ±0.3m, depth ±0.05m; (6) Working tool components: The single repair operation range is 800mm (x direction) × 600mm (y direction), and the guide rail travel is ±400mm in the x direction and ±300mm in the y direction; equipped with a diamond disc underwater cutting tool with a cutting depth of 0~80mm; an underwater diamond drilling tool with a hole diameter of 10~50mm; an underwater diamond grinding tool with a grinding amount ≥1mm / min; and an underwater high-pressure flushing tool with a pressure of 10~20MPa and a flow rate of 5~20L / min. (7) Adsorption components: The working negative pressure range of the adsorption base plate is 0~80kPa, the maximum adsorption force is ≥3000N, and it can withstand the impact of 1.5m / s transverse water flow. The sealing material of the adsorption base plate is seawater resistant rubber, with a service life of ≥1000 times. (8) Power supply and communication: Power is supplied through the umbilical cable, and it also carries optical fiber communication to transmit real-time high-definition video and bidirectional control commands. The communication delay is ≤50ms. The voltage of the umbilical cable power supply is 220V / 380V and the power is ≤5kW. The length of the umbilical cable is 200m, and it carries optical fiber communication with a bandwidth of ≥1Gbps.

[0037] This embodiment is applicable to the inspection and repair of medium-sized dams with a height of 30-100m and an underwater working depth of 0-80m. In a practical engineering application at a hydropower station dam, the robot from Embodiment 1 was used to detect and locate 12 concrete surface cracks in a single underwater operation, taking 4.5 hours; and to repair 8 cracks with a width exceeding 0.3mm in situ, taking approximately 12 hours. Acceptance inspection results showed that the crack sealing rate in the repaired area was 100%, and the water tightness met all standards. Compared with the traditional water level reduction repair scheme, this method saves approximately 5 million cubic meters of water storage and reduces direct economic losses by more than 3 million yuan.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An underwater robot for inspecting and repairing the concrete surface of dams, characterized in that, It includes a robot body module and a surface treatment module, among which, The robot body module includes a power mechanism for driving the robot to achieve multi-degree-of-freedom motion underwater, a motion control mechanism for recording the robot's entry point coordinates and estimating the robot's absolute coordinates in real time underwater, and a detection mechanism for detecting defects on the concrete surface of the dam and determining the location of the defects. The surface treatment module includes a work tool assembly for performing repair work within the work area, a position adjustment assembly for projecting the outline of the work area onto the dam surface and adjusting the robot's position accordingly, and an adsorption assembly for forming a negative pressure adsorption with the dam surface to fix the robot in the work position.

2. The underwater robot for inspecting and repairing the concrete surface of dams according to claim 1, characterized in that, The robot body module also includes a frame body, on which buoyancy material is arranged on both the upper and lower surfaces, and the volume of the buoyancy material on the lower surface is greater than that on the upper surface.

3. The underwater robot for inspecting and repairing the concrete surface of dams according to claim 2, characterized in that, The power mechanism includes The electric pump is housed within the frame body; Multiple vertical thrusters are symmetrically arranged on the top of the frame body. The vertical thrusters are electrically connected to the motor pump, and the vertical thrusters control the robot's heave, pitch and roll motion under the drive of the motor pump. Multiple horizontal thrusters are installed inside the frame body and are evenly arranged along the circumference of the frame body. The horizontal thrusters are electrically connected to the motor pump, and the horizontal thrusters control the robot's forward and backward movement, left and right movement and yaw turning under the drive of the motor pump.

4. The underwater robot for inspecting and repairing the concrete surface of dams according to claim 2, characterized in that, Motion control mechanism includes An embedded control system is located inside the frame body; A waterproof GPS unit is installed on the top of the frame body and electrically connected to the embedded control system. The waterproof GPS unit is used to record the absolute coordinates of the water entry point on the water surface. The pose sensing device is installed inside the frame body and electrically connected to the embedded control system. The pose sensing device is used to estimate the current absolute coordinates of the underwater robot in real time based on the absolute coordinates of the water entry point recorded by the waterproof GPS and the pose inference method.

5. The underwater robot for inspecting and repairing the concrete surface of dams according to claim 4, characterized in that, Position and pose sensing devices include Speed ​​sensors are used to measure the movement speed of robots; An attitude measuring instrument is used to measure the attitude and angular velocity of a robot. A Doppler velocimeter is used to measure the ground velocity of a robot relative to the underwater surface.

6. The underwater robot for inspecting and repairing the concrete surface of dams according to claim 2, characterized in that, Testing institutions include Acoustic imaging equipment, located at the front of the frame body, is used to continuously scan the surface of the dam to detect suspected defects and calculate the relative position of the suspected defects to the robot. The optical imaging equipment, located at the front of the frame body, includes an underwater camera for environmental observation and operational condition acquisition, and a rangefinder for measuring the distance between the underwater camera and the dam surface to correct distortion of the images acquired by the underwater camera.

7. The underwater robot for inspecting and repairing the concrete surface of dams according to claim 2, characterized in that, The surface treatment module also includes a lifting articulated arm mechanism for raising and lowering the working tool assembly and adjusting its position in a two-dimensional plane. The lifting articulated arm mechanism includes... Vertical lifting guide rails are installed at the bottom of the frame body; Two guide slide rods are set parallel to the vertical lifting guide rail; The lifting sliding platform is mounted across two guide rails and can slide up and down along the guide rails; The main articulated arm connects to the lifting sliding platform at one end and to the work tool assembly at the other end.

8. The underwater robot for inspecting and repairing the concrete surface of dams according to claim 7, characterized in that, Position adjustment components include A laser projector, located on the side of the vertical lifting guide rail, is used to project the outline of the working area onto the surface of the dam. The projection acquisition camera, located on the side of the vertical lifting guide rail, is used to transmit the projected image to the computer so that the operator can adjust the robot's position based on the projected position and the crack image.

9. The underwater robot for inspecting and repairing the concrete surface of dams according to claim 7, characterized in that, Adsorption components include The suction base plate is located at the end of the vertical lifting guide rail away from the frame body, and the suction base plate is equipped with a suction port. The water absorption chamber is located inside the frame body and is connected to the suction interface through pipes.

10. A method for inspecting and repairing the surface of concrete dams, characterized in that, Using the underwater robot for dam concrete surface inspection and repair according to any one of claims 1 to 9, the steps include: S1. Control the robot to approach the dam wall. The laser projector of the position adjustment component projects the working position on the dam surface. Adjust the robot position according to the projected image and crack image information. S2. The robot is controlled to achieve stable adhesion to the surface of the dam. S3. If the robot's position meets the repair requirements, start the repair; otherwise, separate from the dam surface and repeat S1. S4. Plan the cutting closed-loop area according to the direction, size and shape of the crack, and use the underwater cutting tool of the working tool component to cut along the closed-loop area; S5. After the underwater cutting tool is reset, the underwater drilling tool of the working tool assembly is activated to drill in the closed loop area to form a repair channel. S6. After the underwater drilling tool is reset, the underwater grinding tool of the working tool component will grind the uneven area in the closed loop to make it smooth. S7. After the underwater grinding tool is reset, start the underwater flushing tool of the working tool component to clean the residue in the closed loop area. Determine whether to return to the corresponding steps in S4, S5, and S6 based on the cleaning effect. S8. After confirming that the area has been cleaned up to standard, inject repair material into the repair channel to complete the crack filling and repair and record the repair location data.

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