Underwater crack detection device and method

Abstract

The invention provides an underwater crack detection device and method. The underwater crack detection device comprises a positioning cylinder, a water retaining mechanism, an adsorption mechanism and a detection module. Compared with the prior art, the underwater crack detection device provided by the invention can ensure that the detection module is kept vertical to the surface of the bridge pile foundation to be detected through the vertical arrangement of the positioning cylinder, guarantees the accuracy of a detection angle, and avoids a detection error caused by angle deviation. The water retaining mechanism effectively obstructs the interference of water flow on a detection area through a plurality of extensible folding telescopic parts and a flexible waterproof layer, and creates a stable detection environment for the detection module. And the adsorption part of the adsorption mechanism is arranged at the extending end of the folding telescopic part, so that the device can be firmly fixed on the surface of the bridge pile foundation, and the stability of the device can be ensured even under the condition of relatively large water flow, thereby improving the detection precision and reliability. Through the combined design, the device can stably work in a complex underwater environment.

Description

Technical Field

[0001] This invention belongs to the field of underwater detection technology, specifically relating to an underwater crack detection device and method. Background Technology

[0002] Underwater crack detection is a technology used to identify surface or internal cracks in underwater structures (such as offshore platforms, bridge foundations, and reservoir dams), and it is widely used in marine engineering, bridge construction, and water conservancy and hydropower. Underwater detection devices are equipment used to detect and monitor the underwater environment and objects. They generally include sonar, underwater cameras, and underwater lidar. Underwater cameras collect underwater light radiation through lenses and convert it into image signals, enabling real-time image acquisition of underwater targets.

[0003] In existing technologies, when using underwater cameras to detect cracks in bridge pile foundations, the underwater cameras visually inspect the cracks underwater. However, water flow disturbances can affect the image quality, equipment stability, and crack identification accuracy. Changes in water velocity gradients can lead to uneven water density, causing irregular refraction of light as it passes through, which can distort the shape and location of cracks in the image (e.g., a straight crack may be imaged as a curve). The thrust of the water flow can also cause the underwater camera to translate or rotate, resulting in rapid changes in the camera's field of view. The crack target may move out of the frame or fail to focus (e.g., crack detection requires the lens to be perpendicular to the structural surface, and water flow deviation can cause shooting angle errors). Waterproof covers are generally used for waterproofing, but during underwater transport, the waterproof covers are difficult to fix accurately at the detection position due to water flow, resulting in poor adaptability and practicality. Summary of the Invention

[0004] This invention provides an underwater crack detection device and method, which aims to solve the problem of poor adaptability and practicality of existing underwater cameras for underwater crack detection due to water flow disturbance.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: to provide an underwater crack detection device and method, wherein the underwater crack detection device includes: A positioning cylinder can be set perpendicularly to the surface of the bridge pile foundation to be inspected, and the positioning cylinder has a detection cavity; A water-blocking mechanism is provided on the positioning cylinder. The water-blocking mechanism has multiple folding and telescopic parts that can extend radially along the positioning cylinder. The multiple folding and telescopic parts are arranged circumferentially and spaced apart along the axis of the positioning cylinder. An interval space is formed between any two folding and telescopic parts. A flexible waterproof layer is provided on the water-blocking mechanism. The flexible waterproof layer is laid on each of the interval spaces when each of the folding and telescopic parts is extended and unfolded. When each of the folding and telescopic parts is retracted and retracted, the flexible waterproof layer is retracted into each of the reduced interval spaces. The adsorption mechanism is provided with multiple adsorption parts, each adsorption part is correspondingly arranged with the corresponding folding telescopic part, each adsorption part is arranged on the protruding end of the folding telescopic part, and each adsorption part is used to adsorb onto the surface of the bridge pile foundation; The detection module is installed inside the detection cavity to detect the surface of the bridge pile foundation to be tested.

[0006] In one possible implementation, the water-blocking mechanism includes: A linkage telescopic frame is provided in multiple units, which are arranged circumferentially along the axis of the positioning cylinder. Each linkage telescopic frame has two hinged drive parts and one hinged extension part. Each linkage telescopic frame is used to extend the hinged extension part outward when the distance between the two hinged drive parts decreases. The linkage telescopic frame is the folding telescopic part. The drive assembly has two sliding parts that are slidably disposed on the outer wall of the positioning cylinder along the axial direction of the positioning cylinder. The two sliding parts are spaced apart along the axial direction of the positioning cylinder, and both sliding parts are hinged to the two hinged drive parts of each of the connecting rod telescopic frames. A flexible waterproof fabric is covered over multiple of the connecting telescopic frames, and the flexible waterproof fabric is the flexible waterproof layer. The outer wall of the positioning cylinder is provided with a slide rail for the two sliding parts to slide.

[0007] In one possible implementation, the two sliding portions of the drive assembly are a first sliding seat and a second sliding seat; the first sliding seat is slidably disposed on the outer wall of the positioning cylinder along the axial direction of the positioning cylinder; the second sliding seat is slidably disposed on the outer wall of the positioning cylinder along the axial direction of the positioning cylinder, and is spaced apart from the first sliding seat along the axial direction of the positioning cylinder.

[0008] In one possible implementation, each of the aforementioned linkage telescopic frames includes: The first drive rod has one end hinged to the first sliding seat, with the hinge axis set along the tangent direction of the detection cylinder axis, and the other end extending outward along the radial direction of the detection cylinder. The second drive rod has one end hinged to the second sliding seat, with the hinge axis set along the tangent direction of the detection cylinder axis, and the other end hinged to the middle section of the first drive rod. An auxiliary drive rod is hinged at one end to the middle section of the second drive rod, with the hinge axis set along the tangent direction of the detection cylinder axis, and the other end extends outward along the radial direction of the detection cylinder. An auxiliary connecting rod is hinged at one end to the extended end of the auxiliary driving rod, and a section of the auxiliary connecting rod near the hinged end of the auxiliary driving rod is hinged to the extended end of the first driving rod. The hinge axis is set along the tangential direction of the axis of the detection cylinder. An elastic rod passes through the first drive rod. One end of the elastic rod is hinged to a section near the hinged end of the auxiliary drive rod and the auxiliary connecting rod. The middle section of the elastic rod is fixedly connected to the auxiliary connecting rod. The other end of the elastic rod extends outward. An extension rod is provided, with one end hinged to the extension end of the elastic rod, the hinge axis being set along the tangential direction of the detection cylinder axis. A section of the extension rod near the hinge end of the elastic rod is hinged to the auxiliary connecting rod, the hinge axis being set along the tangential direction of the detection cylinder axis. The other end of the extension rod extends outward.

[0009] In one possible implementation, the adsorption mechanism includes: Multiple hinge seats are provided, each hinge seat is correspondingly arranged with each extension rod, and each hinge seat is hinged to the extension end of the corresponding extension rod. The hinge axis is arranged along the tangential direction of the detection cylinder axis. The suction cup is provided in multiple parts, each suction cup is correspondingly arranged with each of the hinge seats, each suction cup is fixed on the corresponding hinge seat, and each suction cup is connected to a gas supply unit. The suction cup is the adsorption part.

[0010] In one possible implementation, the adsorption mechanism further includes a positioning adsorption seat disposed at one end of the positioning cylinder, the positioning adsorption seat being used to abut against the surface of the bridge pile foundation to be tested, and the positioning adsorption seat being connected to a gas supply unit.

[0011] In one possible implementation, the underwater crack detection device further includes multiple flow guiding structures, each flow guiding structure corresponding to each of the extended rods, each flow guiding structure being hinged to the middle section of the extended rod, and each flow guiding structure comprising: A hinged connecting rod, wherein a hinge block is provided on the hinged connecting rod, the hinge block is located in the middle section of the hinged connecting rod, the hinge block is hinged to the middle section of the extension rod, and the hinge axis is set along the tangential direction of the axis of the detection cylinder. Two guide vanes are provided, and the two guide vanes are respectively hinged to both sides of the hinge link. The hinge axis of each guide vane is set along the extension direction of the hinge link. Two first torsion springs are provided, and the two first torsion springs are correspondingly arranged with the two guide plates. Each first torsion spring is used to make the corresponding guide plate have a tendency to always be extended.

[0012] In one possible implementation, the underwater crack detection device further includes a flow guide cover, which is slidably disposed on the positioning cylinder, and the flow guide cover includes: The cover plate slide is slidably disposed on the positioning cylinder along the axial direction of the detection cylinder cavity; Multiple hinged beams are provided, and each hinged beam is arranged circumferentially at intervals along the axis of the detection cylinder. One end of each hinged beam is hinged to the cover plate slide, and the other end of each hinged beam extends radially along the detection cylinder. The fan-shaped cover plate assembly is provided in multiple groups. Each group of fan-shaped cover plates is correspondingly arranged with each of the hinge beams. Each fan-shaped cover plate assembly includes two fan-shaped plates, which are respectively hinged to both sides of the hinge beam. The hinge axis of each fan-shaped plate is arranged along the extension direction of the hinge beam. Two second torsion springs are provided, and the two second torsion springs are correspondingly arranged with the two sector plates. Each second torsion spring is used to make the corresponding sector plate tend to always be extended.

[0013] In one possible implementation, the positioning cylinder is provided with a shock-absorbing structure, the shock-absorbing structure comprising: A reset cylinder is coaxially disposed within the detection cylinder cavity, and the reset cylinder is spaced apart from the positioning cylinder. Multiple reset springs are provided, each of which is disposed between the reset cylinder and the positioning cylinder. The reset springs are used to ensure that the axis of the reset cylinder is always collinear with the axis of the positioning cylinder.

[0014] In one possible implementation, the underwater crack detection method, including the underwater crack detection device, comprises the following steps: After securing the device, an underwater robot carrying an underwater crack detection device is moved to the surface of the bridge pile foundation to be inspected. Once the position of the positioning cylinder is determined, the positioning cylinder is placed against the point to be inspected, and then each folding and telescopic part of the water-blocking mechanism is unfolded, with the adsorption part on each folding and telescopic part adhering to the surface of the bridge pile foundation. The position of the adsorption mechanism is fixed. After the position of the adsorption mechanism is determined, the water flow is blocked by the flexible waterproof layer of the water-blocking mechanism. Underwater camera inspection preparation: An underwater robot carries the underwater camera to the surface of the bridge pile foundation to be inspected, and inserts the underwater camera into the inspection cylinder. Underwater camera inspection involves controlling the underwater camera to move within the inspection chamber toward the surface of the bridge pile foundation to be inspected.

[0015] In this implementation, compared with existing technologies, the vertical setting of the positioning cylinder ensures that the detection module remains perpendicular to the surface of the bridge pile foundation to be inspected, guaranteeing the accuracy of the detection angle and avoiding detection errors caused by angular deviations. The water-blocking mechanism, through multiple extendable folding telescopic parts and a flexible waterproof layer, effectively blocks water flow interference to the detection area, creating a stable detection environment for the detection module. The adsorption part of the adsorption mechanism is located at the extended end of the folding telescopic parts, firmly fixing the device to the bridge pile foundation surface, ensuring the stability of the device even under strong water flow, thereby improving the accuracy and reliability of the detection. This combined design enables the device to operate stably in complex underwater environments, effectively solving the problem of water flow disturbance affecting detection in existing technologies, improving the accuracy and stability of underwater crack detection, and demonstrating good adaptability and practicality. Attached Figure Description

[0016] Figure 1 A schematic diagram of the underwater crack detection device provided in an embodiment of the present invention. Figure 1 ; Figure 2 A schematic diagram of the underwater crack detection device provided in an embodiment of the present invention. Figure 2 ; Figure 3 for Figure 2 Enlarged structural diagram at point A; Figure 4 This is a schematic diagram of the structure of the guide cover plate of the underwater crack detection device provided in an embodiment of the present invention; Figure 5 This is a top view of the positioning cylinder of the underwater crack detection device provided in an embodiment of the present invention. Figure 6 This is a schematic diagram illustrating the steps of the underwater crack detection method provided in an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 10. Positioning cylinder; 11. Reset cylinder; 12. Reset spring; 20. Water-blocking mechanism; 21. Linkage telescopic frame; 211. First drive rod; 212. Second drive rod; 213. Auxiliary drive rod; 214. Auxiliary connecting rod; 215. Elastic rod; 216. Extending rod; 22. Drive assembly; 221. First sliding seat; 222. Second sliding seat; 23. Flexible waterproof cloth; 30. Adsorption mechanism; 31. Hinge seat; 32. Suction cup; 33. Positioning adsorption seat; 40. Flow guiding structure; 41. Hinge connecting rod; 42. Flow guiding plate; 50. Flow guiding cover plate; 51. Cover plate slide; 52. Hinge beam; 53. Fan-shaped cover plate assembly; 531. Fan-shaped plate. Detailed Implementation

[0018] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0019] It should be noted that the terms "length", "width", "height", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", and "tail" 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 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, they should not be construed as limitations on the present invention.

[0020] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part of a structure. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, or to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] Furthermore, the terms "first" and "second" 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Additionally, "multiple" and "several" mean two or more, unless otherwise explicitly specified.

[0022] Please refer to the following: Figures 1 to 6The underwater crack detection device and method provided by the present invention will now be described. The underwater crack detection device includes a positioning cylinder 10, a water-blocking mechanism 20, an adsorption mechanism 30, and a detection module. The positioning cylinder 10 is perpendicularly arranged to the surface of the bridge pile foundation to be detected and has a detection cavity. The water-blocking mechanism 20 is disposed on the positioning cylinder 10 and has multiple folding telescopic parts that can extend radially along the positioning cylinder 10. The multiple folding telescopic parts are arranged annularly at intervals along the axis of the positioning cylinder 10. An interval space is formed between any two folding telescopic parts. A flexible waterproof layer is provided on the water-blocking mechanism 20. The flexible waterproof layer is laid on each interval space when each folding telescopic part is extended and retracted into the reduced interval space. The adsorption mechanism 30 has multiple adsorption parts, each adsorption part corresponding to a corresponding folding telescopic part. Each adsorption part is disposed on the extended end of the folding telescopic part and is used to adsorb onto the surface of the bridge pile foundation. The detection module is installed inside the detection cylinder to detect the surface of the bridge pile foundation to be tested.

[0023] The underwater crack detection device provided in this embodiment, compared with the prior art, ensures that the detection module remains perpendicular to the surface of the bridge pile foundation to be detected by vertically setting the positioning cylinder 10, thus guaranteeing the accuracy of the detection angle and avoiding detection errors caused by angle deviation. The water-blocking mechanism 20, through multiple extendable folding telescopic parts and a flexible waterproof layer, effectively blocks the interference of water flow on the detection area, creating a stable detection environment for the detection module. The adsorption part of the adsorption mechanism 30 is located at the extended end of the folding telescopic parts, which can firmly fix the device to the surface of the bridge pile foundation, ensuring the stability of the device even under strong water flow, thereby improving the accuracy and reliability of the detection. This combined design enables the device to work stably in complex underwater environments, effectively solving the problem of water flow disturbance affecting the detection in the prior art, improving the accuracy and stability of underwater crack detection, and demonstrating good adaptability and practicality.

[0024] In some embodiments, the water-blocking mechanism 20 may employ, for example... Figure 2 The structure shown. See also Figure 2The water-blocking mechanism 20 includes a linkage telescopic frame 21, a drive assembly 22, and a flexible waterproof cloth 23. Multiple linkage telescopic frames 21 are provided, arranged annularly at intervals along the axis of the positioning cylinder 10. Each linkage telescopic frame 21 has two hinged drive parts and one hinged extension part. The hinged extension part extends outward when the distance between the two hinged drive parts decreases; the linkage telescopic frame 21 is a folding telescopic part. The drive assembly 22 has two sliding parts slidably disposed on the outer wall of the positioning cylinder 10 along the axial direction of the positioning cylinder 10. The two sliding parts are spaced apart along the axial direction of the positioning cylinder 10, and both sliding parts are hinged to the two hinged drive parts of each linkage telescopic frame 21. The flexible waterproof cloth 23 covers the multiple linkage telescopic frames 21, and the flexible waterproof cloth 23 is a flexible waterproof layer.

[0025] The outer wall of the positioning cylinder 10 is provided with a slide rail for the two sliding parts to slide.

[0026] The water-blocking mechanism 20, composed of the telescopic linkage 21, the drive assembly 22, and the flexible waterproof fabric 23, possesses strong flexibility and adaptability. Through the coordinated operation of multiple hinged components, the telescopic linkage 21 can flexibly adjust the extension length and angle of the folding telescopic section according to different pile foundation surface shapes and inspection requirements, better conforming to the pile foundation surface. The two sliding parts of the drive assembly 22 are hinged to the telescopic linkage 21, enabling precise control of the extension and retraction of the telescopic linkage 21, making the operation of the water-blocking mechanism 20 more stable and reliable. When the telescopic linkage 21 is extended, the flexible waterproof fabric 23 effectively covers the interval space, blocking water flow. When the telescopic linkage 21 is retracted, it can be easily stored in the interval space without affecting other operations of the device. This design ensures both water-blocking effectiveness and maintains the overall mobility of the device, improving its adaptability to different underwater environments.

[0027] In some embodiments, the driving component 22 described above may employ, for example... Figure 2 The structure shown. See also Figure 2 The two sliding parts of the drive assembly 22 are a first sliding seat 221 and a second sliding seat 222. The first sliding seat 221 is slidably disposed on the outer wall of the positioning cylinder 10 along the axial direction of the positioning cylinder 10. The second sliding seat 222 is slidably disposed on the outer wall of the positioning cylinder 10 along the axial direction of the positioning cylinder 10, and is spaced apart from the first sliding seat 221 along the axial direction of the positioning cylinder 10.

[0028] The first sliding seat 221 and the second sliding seat 222 serve as sliding parts of the drive assembly 22, enabling precise sliding along the axis of the positioning cylinder 10. They are hinged to the hinged drive parts of each connecting rod telescopic frame 21. By controlling the distance between the two sliding seats, the movement of the connecting rod telescopic frame 21 can be precisely controlled. This design makes the expansion and contraction of the water-blocking mechanism 20 smoother, allowing for flexible adjustment of the water-blocking mechanism 20's state according to actual testing needs, thus improving the reliability and controllability of the water-blocking mechanism 20. Simultaneously, the two sliding seats simplify the structure of the drive assembly 22, facilitating installation and maintenance.

[0029] In some embodiments, the aforementioned linkage telescopic frame 21 may adopt the following... Figure 2 , Figure 3 The structure shown. See also Figure 2 , Figure 3 Each linkage telescopic frame 21 includes a first drive rod 211, a second drive rod 212, an auxiliary drive rod 213, an elastic rod 215, and an extension rod 216. One end of the first drive rod 211 is hinged to the first sliding seat 221, with the hinge axis tangential to the axis of the detection cylinder, and the other end extends radially outward along the detection cylinder. One end of the second drive rod 212 is hinged to the second sliding seat 222, with the hinge axis tangential to the axis of the detection cylinder, and the other end is hinged to the middle section of the first drive rod 211. One end of the auxiliary drive rod 213 is hinged to the middle section of the second drive rod 212, with the hinge axis tangential to the axis of the detection cylinder, and the other end extends radially outward along the detection cylinder. One end of the auxiliary connecting rod 214 is hinged to the extended end of the auxiliary driving rod 213. A section of the auxiliary connecting rod 214 near the hinged end of the auxiliary driving rod 213 is hinged to the extended end of the first driving rod 211. The hinge axis is set along the tangential direction of the detection cylinder axis. An elastic rod 215 passes through the first driving rod 211. One end of the elastic rod 215 is hinged to a section near the hinged end of the auxiliary driving rod 213 and the auxiliary connecting rod 214. The middle section of the elastic rod 215 is fixedly connected to the auxiliary connecting rod 214. The other end of the elastic rod 215 extends outward. One end of the extended rod 216 is hinged to the extended end of the elastic rod 215. The hinge axis is set along the tangential direction of the detection cylinder axis. A section of the extended rod 216 near the hinged end of the elastic rod 215 is hinged to the auxiliary connecting rod 214. The hinge axis is set along the tangential direction of the detection cylinder axis. The other end of the extended rod 216 extends outward.

[0030] The linkage telescopic frame 21, composed of connecting rods, elastic rods 215, and extension rods 216, effectively converts the driving force of the drive assembly 22 into the extension and retraction motion of the extension rods 216 through multi-rod hinges, ensuring the stability and reliability of the movement. The elastic rods 215 not only provide cushioning during the extension and retraction of the extension rods 216, preventing damage to the device from rigid collisions, but also automatically adjust the position of the extension rods 216 according to the unevenness of the pile foundation surface, allowing the adsorption part to better conform to the pile foundation surface. This structural design enables the linkage telescopic frame 21 to adapt to complex and variable underwater environments, improving the adaptability and reliability of the device.

[0031] In some embodiments, the adsorption mechanism 30 described above may employ, for example... Figure 2 , Figure 3 The structure shown. See also Figure 2 , Figure 3 The adsorption mechanism 30 includes a hinge seat 31 and suction cups 32. Multiple hinge seats 31 are provided, each corresponding to a corresponding extension rod 216. Each hinge seat 31 is hinged to the extension end of its corresponding extension rod 216, and the hinge axis is tangential to the axis of the detection cylinder. Multiple suction cups 32 are provided, each corresponding to a corresponding hinge seat 31. Each suction cup 32 is fixed to its corresponding hinge seat 31 and connected to a gas supply unit; the suction cup 32 serves as the adsorption part.

[0032] The adsorption mechanism 30, composed of the hinged seat 31 and the suction cup 32, plays a crucial role in enhancing adsorption stability and adaptability. The hinged seat 31 is hinged to the extended end of the extension rod 216, allowing the suction cup 32 to flexibly adjust its angle within a certain range, better conforming to different shapes and angles of the bridge pile foundation surface. Regardless of whether the pile foundation surface is flat, curved, or has a certain inclination, the suction cup 32 can find the optimal adsorption position through the rotation of the hinged seat 31, thereby enhancing adsorption stability. The gas supply unit is connected to the suction cup 32, enabling precise control of the gas pressure within the suction cup 32 and adjustment of the adsorption force. Under different water flow rates and water pressures, the adsorption effect of the suction cup 32 can be ensured by adjusting the gas supply, improving the adaptability and controllability of the adsorption mechanism 30.

[0033] In some embodiments, the adsorption mechanism 30 described above may employ, for example... Figure 2 , Figure 3 The structure shown. See also Figure 2 , Figure 3 The adsorption mechanism 30 also includes a positioning adsorption seat 33, which is disposed at one end of the positioning cylinder 10. The positioning adsorption seat 33 is used to abut against the surface of the bridge pile foundation to be tested. The positioning adsorption seat 33 is connected to the gas supply unit.

[0034] The positioning adsorption seat 33 is located at one end of the positioning cylinder 10. During the testing process, it first comes into contact with the surface of the bridge pile foundation to be tested, serving as an auxiliary initial positioning device. This helps the device quickly and accurately locate the testing position, improving testing efficiency. Simultaneously, the positioning adsorption seat 33 also shares some of the adsorption force, working together with the suction cup 32 on the extension rod 216 to firmly fix the device to the pile foundation surface. In situations with strong water flow or uneven pile foundation surfaces, the presence of the positioning adsorption seat 33 enhances the overall stability of the device, making the testing process more reliable and reducing testing errors caused by device shaking.

[0035] In some embodiments, the above-described underwater crack detection device may employ, for example... Figure 1 The structure shown. See also Figure 1 The underwater crack detection device also includes multiple flow guiding structures 40, each corresponding to a protruding rod 216. Each flow guiding structure 40 is hinged to the middle section of the protruding rod 216. Each flow guiding structure 40 includes a hinged connecting rod 41, a flow guiding plate 42, and a first torsion spring. The hinged connecting rod 41 has a hinge block located in the middle section of the connecting rod 41, hinged to the middle section of the protruding rod 216. The hinge axis is arranged tangentially to the axis of the detection cylinder. Two flow guiding plates 42 are provided, each hinged to one side of the hinged connecting rod 41. The hinge axis of each flow guiding plate 42 is arranged along the extension direction of the hinged connecting rod 41. Two first torsion springs are provided, corresponding to two flow guiding plates 42. Each first torsion spring is used to ensure that the corresponding flow guiding plate 42 always has a tendency to extend.

[0036] The flow guiding structure 40 is highly effective in reducing water flow impact, protecting the device, and optimizing the testing environment. The combination of the hinged connecting rod 41 and the flow guide plate 42 automatically adjusts the angle of the flow guide plate 42 according to the direction and speed of the water flow, effectively changing the water flow direction and allowing the water to bypass the device, thus reducing the impact force on the device. The first torsion spring keeps the flow guide plate 42 in an extended state, ensuring the effectiveness of the flow guiding structure 40. Under conditions of significant water flow changes, the first torsion spring allows the flow guide plate 42 to quickly return to the optimal flow guiding angle, ensuring the stability of the flow guiding structure 40. Through the function of the flow guiding structure 40, not only is the device protected from direct water flow impact, extending its service life, but the testing environment is also optimized, reducing water flow interference with the testing results and improving the accuracy of the testing.

[0037] In some embodiments, the above-described underwater crack detection device may employ, for example... Figure 1 , Figure 4 The structure shown. See also Figure 1 , Figure 4The underwater crack detection device also includes a flow guide cover 50, which is slidably mounted on the positioning cylinder 10. The flow guide cover 50 includes: a cover slide 51, a hinge beam 52, a fan-shaped cover assembly 53, and a second torsion spring. The cover slide 51 is slidably mounted on the positioning cylinder 10 along the axial direction of the detection cylinder cavity. Multiple hinge beams 52 are provided, and each hinge beam 52 is arranged annularly at intervals along the axial direction of the detection cylinder cavity. One end of each hinge beam 52 is hinged to the cover slide 51, and the other end of each hinge beam 52 extends radially along the detection cylinder cavity. Multiple fan-shaped cover assemblies 53 are provided, and each fan-shaped cover assembly corresponds to each hinge beam 52. Each fan-shaped cover assembly 53 includes two fan-shaped plates 531, which are respectively hinged to both sides of the hinge beam 52. The hinge axis of each fan-shaped plate 531 is arranged along the extension direction of the hinge beam 52. Two second torsion springs are provided, and the two second torsion springs are correspondingly arranged with the two sector plates 531. Each second torsion spring is used to make the corresponding sector plate 531 always have the tendency to unfold.

[0038] The flow guide cover 50 is significant in optimizing the water flow environment, protecting the detection module, and improving the overall performance of the device. The cover slide 51, hinged beam 52, sector-shaped cover assembly 53, and second torsion spring work together. When water impacts the device, the sector-shaped cover assembly 53 unfolds under the action of the second torsion spring, blocking the water flow from impacting the detection cylinder cavity and protecting the detection module from direct water flow influence. Simultaneously, the flow guide cover 50 can also provide secondary flow guidance, further optimizing the water flow environment and reducing water flow interference with the device. When the device is moved or detection is not required, the flow guide cover 50 can be retracted by sliding the cover slide 51 without affecting other operations of the device. This design improves the overall performance and adaptability of the device, enabling it to operate in harsher underwater environments.

[0039] In some embodiments, the positioning cylinder 10 may be adopted as follows: Figure 5 The structure shown. See also Figure 5 The positioning cylinder 10 is equipped with a shock-absorbing structure, which includes a reset cylinder 11 and a reset spring 12. The reset cylinder 11 is coaxially disposed within the detection cylinder cavity, and the reset cylinder 11 and the positioning cylinder 10 are spaced apart. Multiple reset springs 12 are provided, and each reset spring 12 is disposed between the reset cylinder 11 and the positioning cylinder 10. The reset springs 12 are used to ensure that the axis of the reset cylinder 11 is always collinear with the axis of the positioning cylinder 10.

[0040] The vibration damping structure plays a crucial role in reducing the impact of underwater vibration on the detection module, ensuring detection accuracy, and extending equipment lifespan. The coordinated operation of the damping cylinder and the return spring 12 effectively buffers the impact of underwater vibration on the detection module. When the device is subjected to vibration, the damping cylinder, under the action of the return spring 12, can shift relative to the positioning cylinder 10 to absorb vibration energy, minimizing the vibration experienced by the detection module. This not only ensures stable operation of the detection module in vibration environments and improves detection accuracy, but also reduces vibration damage to internal components of the detection module, extends equipment lifespan, and lowers maintenance costs.

[0041] In some embodiments, the above-described underwater crack detection method can be employed as follows: Figure 6 The steps are shown. See also... Figure 6 The steps include: preparation for fixing, determining the position of the positioning cylinder 10, fixing the position of the adsorption mechanism 30, preparation for underwater camera detection, and underwater camera detection. Preparation for fixing involves an underwater robot carrying the underwater crack detection device to the surface of the bridge pile foundation to be inspected. Determining the position of the positioning cylinder 10 involves placing the positioning cylinder 10 against the inspection point, and then unfolding the folding and telescopic parts of the water-blocking mechanism 20, with the adsorption parts on each folding and telescopic part adhering to the surface of the bridge pile foundation. Determining the position of the adsorption mechanism 30 involves using the flexible waterproof layer of the water-blocking mechanism 20 to block water flow after the adsorption mechanism 30 is positioned. Preparation for underwater camera detection involves an underwater robot carrying the underwater camera to the surface of the bridge pile foundation to be inspected, and inserting the underwater camera into the detection cylinder cavity. Underwater camera detection involves controlling the underwater camera to move towards the surface of the bridge pile foundation within the detection cylinder cavity for detection.

[0042] The underwater crack detection method utilizes a multi-step, orderly operation to fully leverage the functions of each component of the device. First, an underwater robot accurately transports the device to the inspection location, providing a foundation for subsequent operations. Then, through the coordinated work of the positioning cylinder 10, the water-blocking mechanism 20, and the adsorption mechanism 30, the device is stably fixed on the pile foundation surface and water flow is blocked, creating favorable conditions for underwater camera inspection. Finally, the underwater camera performs inspection within the inspection cylinder cavity, acquiring high-quality crack images and data. This method effectively improves inspection efficiency and accuracy, reduces errors and interference during the inspection process, and provides an efficient and reliable operating procedure for underwater crack detection.

[0043] The underwater crack detection device provided in this embodiment operates as follows: In the preparation stage, the operator first formulates a detailed detection plan based on the location of the bridge pile foundation to be inspected and the underwater environment information, including the underwater robot's travel route and the debugging parameters of the detection device. Next, the underwater crack detection device is securely connected to the underwater robot to ensure the device's safety and stability during transportation. The underwater robot is then started, and its various functions are comprehensively checked, such as the power system, thrusters, sensors, and communication modules, to ensure normal operation. Simultaneously, the underwater crack detection device undergoes preliminary debugging, checking the verticality of the positioning cylinder 10, the folding and telescopic function of the water-blocking mechanism 20, the adsorption force of the adsorption mechanism 30, and the working status of the detection module, ensuring that all parts of the device are in good working order. Then, the underwater robot carries the underwater crack detection device and moves along the preset route towards the surface of the bridge pile foundation to be inspected. During the movement, the underwater robot uses its onboard sonar, camera, and other sensors to perceive the surrounding underwater environment in real time, avoiding obstacles and ensuring safe arrival at the detection location. During the positioning and fixing phase, when the underwater robot carrying the detection device arrives near the surface of the bridge pile foundation to be inspected, the positioning cylinder 10 is accurately positioned against the inspection point using a high-precision positioning system. At this time, the drive assembly 22 of the water-blocking mechanism 20 is activated, causing the two sliding parts (first sliding seat 221 and second sliding seat 222) to slide relative to each other along the axis of the positioning cylinder 10. As the sliding parts slide, the distance between the two hinged drive parts of the connecting rod telescopic frame 21 decreases, causing the hinged extension part (extension rod 216) to extend outward, and multiple connecting rod telescopic frames 21 unfold synchronously. During the outward extension of the extension rod 216, the hinge seat 31 of the adsorption mechanism 30 moves together with the extension rod 216, and the suction cup 32 gradually approaches the surface of the bridge pile foundation. When the suction cup 32 contacts the pile foundation surface, the gas supply unit supplies gas into the suction cup 32, creating a negative pressure inside the suction cup 32, thereby tightly adhering to the surface of the bridge pile foundation. Simultaneously, the positioning adsorption seat 33 also abuts against the surface of the bridge pile foundation to be inspected, assisting the device in initial positioning and sharing some of the adsorption force. After all adsorption parts are attached to the surface of the bridge pile foundation, the flexible waterproof cloth 23 of the water-blocking mechanism 20, under the action of the connecting rod telescopic frame 21 unfolding, is laid in each interval space, forming an effective water-blocking barrier to prevent water flow from interfering with the inspection area. The two sliding parts (first sliding seat 221 and second sliding seat 222) can be driven by an underwater robot or by a drive unit such as a rodless motor or hydraulic cylinder. During the inspection phase, after the device completes positioning and fixation, the underwater robot carries the underwater camera to the surface of the bridge pile foundation to be inspected and inserts the underwater camera into the inspection cylinder. The underwater camera establishes a communication connection with the inspection module and receives control commands. The control unit issues commands to control the underwater camera to move towards the surface of the bridge pile foundation to be inspected within the inspection cylinder.During movement, the underwater camera uses its high-definition lens and advanced image sensor to acquire images of the bridge pile foundation surface row by row and column by column. The acquired image data is transmitted in real time to the control center or data processing terminal on the water via communication lines. During image acquisition, if a significant change in water flow speed or direction is detected, the flow guiding structure 40 and the flow guiding cover 50 will automatically activate. Under the action of the water flow, the flow guiding plate 42 of the flow guiding structure 40 automatically adjusts its angle through the rotation of the hinged connecting rod 41, changing the direction of the water flow and reducing the impact force of the water flow on the device. The fan-shaped cover group 53 of the flow guiding cover 50 unfolds under the action of the second torsion spring, further blocking the water flow from impacting the detection cylinder cavity, protecting the underwater camera and detection module from the direct impact of the water flow, and ensuring the stability and accuracy of image acquisition. At the same time, the shock-absorbing structure inside the positioning cylinder 10 also effectively buffers underwater vibrations, ensuring that the underwater camera operates in a stable environment and improving the quality of image acquisition. In the final stage, after the underwater camera completes image acquisition of the predetermined detection area, the control unit issues a command to stop the underwater camera's movement and remove it from the detection cylinder. Then, the gas supply unit releases gas into the suction cup 32, causing the suction cup 32 to detach from the bridge pile foundation surface. Simultaneously, the drive assembly 22 moves in the opposite direction, causing the two sliding parts to slide in opposite directions along the axis of the positioning cylinder 10. The distance between the hinged drive parts of the linkage telescopic frame 21 increases, the extension rod 216 retracts inward, and the flexible waterproof cloth 23 of the water-blocking mechanism 20 also retracts into it as the space decreases. The underwater robot, carrying the underwater crack detection device, detaches from the bridge pile foundation surface and returns to the surface or a designated recovery position according to the preset return route. During the return process, the sensors on the underwater robot are used again to monitor the surrounding environment in real time to ensure a safe return. After returning to the surface or recovery position, the detection device is removed from the underwater robot, cleaned, maintained, and inspected to prepare for the next detection task. Meanwhile, the image data collected by the underwater camera is further processed and analyzed. Using image processing software and crack recognition algorithms, the location, length, width, depth and other parameters of the crack are accurately measured and evaluated, and a detailed inspection report is generated.

[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An underwater crack detection device, characterized in that, include: A positioning cylinder can be set perpendicularly to the surface of the bridge pile foundation to be inspected, and the positioning cylinder has a detection cavity; A water-blocking mechanism is provided on the positioning cylinder. The water-blocking mechanism has multiple folding and telescopic parts that can extend radially along the positioning cylinder. The multiple folding and telescopic parts are arranged circumferentially and spaced apart along the axis of the positioning cylinder. An interval space is formed between any two folding and telescopic parts. A flexible waterproof layer is provided on the water-blocking mechanism. The flexible waterproof layer is laid on each of the interval spaces when each of the folding and telescopic parts is extended and unfolded. When each of the folding and telescopic parts is retracted and retracted, the flexible waterproof layer is retracted into each of the reduced interval spaces. The adsorption mechanism is provided with multiple adsorption parts, each adsorption part is correspondingly arranged with the corresponding folding telescopic part, each adsorption part is arranged on the protruding end of the folding telescopic part, and each adsorption part is used to adsorb onto the surface of the bridge pile foundation; The detection module is installed inside the detection cavity to detect the surface of the bridge pile foundation to be tested.

2. The underwater crack detection device as described in claim 1, characterized in that, The water-blocking mechanism includes: A linkage telescopic frame is provided in multiple units, which are arranged circumferentially along the axis of the positioning cylinder. Each linkage telescopic frame has two hinged drive parts and one hinged extension part. Each linkage telescopic frame is used to extend the hinged extension part outward when the distance between the two hinged drive parts decreases. The linkage telescopic frame is the folding telescopic part. The drive assembly has two sliding parts that are slidably disposed on the outer wall of the positioning cylinder along the axial direction of the positioning cylinder. The two sliding parts are spaced apart along the axial direction of the positioning cylinder, and both sliding parts are hinged to the two hinged drive parts of each of the connecting rod telescopic frames. A flexible waterproof fabric is covered over multiple of the connecting telescopic frames, and the flexible waterproof fabric is the flexible waterproof layer. The outer wall of the positioning cylinder is provided with a slide rail for the two sliding parts to slide.

3. The underwater crack detection device as described in claim 2, characterized in that, The two sliding parts of the drive assembly are a first sliding seat and a second sliding seat; the first sliding seat is slidably disposed on the outer wall of the positioning cylinder along the axial direction of the positioning cylinder; the second sliding seat is slidably disposed on the outer wall of the positioning cylinder along the axial direction of the positioning cylinder, and is spaced apart from the first sliding seat along the axial direction of the positioning cylinder.

4. The underwater crack detection device as described in claim 3, characterized in that, Each of the aforementioned linkage telescopic frames includes: The first drive rod has one end hinged to the first sliding seat, with the hinge axis set along the tangent direction of the detection cylinder axis, and the other end extending outward along the radial direction of the detection cylinder. The second drive rod has one end hinged to the second sliding seat, with the hinge axis set along the tangent direction of the detection cylinder axis, and the other end hinged to the middle section of the first drive rod. An auxiliary drive rod is hinged at one end to the middle section of the second drive rod, with the hinge axis set along the tangent direction of the detection cylinder axis, and the other end extends outward along the radial direction of the detection cylinder. An auxiliary connecting rod is hinged at one end to the extended end of the auxiliary driving rod, and a section of the auxiliary connecting rod near the hinged end of the auxiliary driving rod is hinged to the extended end of the first driving rod. The hinge axis is set along the tangential direction of the axis of the detection cylinder. An elastic rod passes through the first drive rod. One end of the elastic rod is hinged to a section near the hinged end of the auxiliary drive rod and the auxiliary connecting rod. The middle section of the elastic rod is fixedly connected to the auxiliary connecting rod. The other end of the elastic rod extends outward. An extension rod is provided, with one end hinged to the extension end of the elastic rod, the hinge axis being set along the tangential direction of the detection cylinder axis. A section of the extension rod near the hinge end of the elastic rod is hinged to the auxiliary connecting rod, the hinge axis being set along the tangential direction of the detection cylinder axis. The other end of the extension rod extends outward.

5. The underwater crack detection device as described in claim 4, characterized in that, The adsorption mechanism includes: Multiple hinge seats are provided, each hinge seat is correspondingly arranged with each extension rod, and each hinge seat is hinged to the extension end of the corresponding extension rod. The hinge axis is arranged along the tangential direction of the detection cylinder axis. The suction cup is provided in multiple parts, each suction cup is correspondingly arranged with each of the hinge seats, each suction cup is fixed on the corresponding hinge seat, and each suction cup is connected to a gas supply unit. The suction cup is the adsorption part.

6. The underwater crack detection device as described in claim 5, characterized in that, The adsorption mechanism further includes a positioning adsorption seat, which is disposed at one end of the positioning cylinder and is used to abut against the surface of the bridge pile foundation to be tested. The positioning adsorption seat is connected to a gas supply unit.

7. The underwater crack detection device as described in claim 4, characterized in that, The underwater crack detection device further includes multiple flow guiding structures, each flow guiding structure being correspondingly arranged with each of the extended rods. Each flow guiding structure is hinged to the middle section of the extended rod, and each flow guiding structure includes: A hinged connecting rod, wherein a hinge block is provided on the hinged connecting rod, the hinge block is located in the middle section of the hinged connecting rod, the hinge block is hinged to the middle section of the extension rod, and the hinge axis is set along the tangential direction of the axis of the detection cylinder. Two guide vanes are provided, and the two guide vanes are respectively hinged to both sides of the hinge link. The hinge axis of each guide vane is set along the extension direction of the hinge link. Two first torsion springs are provided, and the two first torsion springs are correspondingly arranged with the two guide plates. Each first torsion spring is used to make the corresponding guide plate have a tendency to always be extended.

8. The underwater crack detection device as described in claim 1, characterized in that, The underwater crack detection device further includes a flow guide cover, which is slidably disposed on the positioning cylinder. The flow guide cover includes: The cover plate slide is slidably disposed on the positioning cylinder along the axial direction of the detection cylinder cavity; Multiple hinged beams are provided, and each hinged beam is arranged circumferentially at intervals along the axis of the detection cylinder. One end of each hinged beam is hinged to the cover plate slide, and the other end of each hinged beam extends radially along the detection cylinder. The fan-shaped cover plate assembly is provided in multiple groups. Each group of fan-shaped cover plates is correspondingly arranged with each of the hinge beams. Each fan-shaped cover plate assembly includes two fan-shaped plates, which are respectively hinged to both sides of the hinge beam. The hinge axis of each fan-shaped plate is arranged along the extension direction of the hinge beam. Two second torsion springs are provided, and the two second torsion springs are correspondingly arranged with the two sector plates. Each second torsion spring is used to make the corresponding sector plate tend to always be extended.

9. The underwater crack detection device as described in claim 1, characterized in that, The positioning cylinder is equipped with a shock-absorbing structure, which includes: A reset cylinder is coaxially disposed within the detection cylinder cavity, and the reset cylinder is spaced apart from the positioning cylinder. Multiple reset springs are provided, each of which is disposed between the reset cylinder and the positioning cylinder. The reset springs are used to ensure that the axis of the reset cylinder is always collinear with the axis of the positioning cylinder.

10. A method for detecting underwater cracks, comprising the underwater crack detection device as described in any one of claims 1-9, wherein the steps include: After securing the device, an underwater robot carrying an underwater crack detection device is moved to the surface of the bridge pile foundation to be inspected. Once the position of the positioning cylinder is determined, the positioning cylinder is placed against the point to be inspected, and then each folding and telescopic part of the water-blocking mechanism is unfolded, with the adsorption part on each folding and telescopic part adhering to the surface of the bridge pile foundation. The position of the adsorption mechanism is fixed. After the position of the adsorption mechanism is determined, the water flow is blocked by the flexible waterproof layer of the water-blocking mechanism. Underwater camera inspection preparation: An underwater robot carries the underwater camera to the surface of the bridge pile foundation to be inspected, and inserts the underwater camera into the inspection cylinder. Underwater camera inspection involves controlling the underwater camera to move within the inspection chamber toward the surface of the bridge pile foundation to be inspected.

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