Robot device for underwater concrete crack detection

Abstract

The invention relates to a robot device for underwater concrete crack detection. The robot device comprises an external supporting frame, an equipment cabin, a camera, a cleaning rotary brush and a propelling system. The composite optical observation window has the beneficial effects that the composite optical observation window is a three-layer optical cabin, a clear water layer is filled with water, and a water body is directly taken from a clear part of an operation water area, so that the optical consistency of the clear water layer and an external water area is ensured, the three-layer optical cabin fundamentally solves the problems of optical distortion and blurring of underwater imaging, and a clear image is obtained; the integrated rotating brush can clear surface attachments before imaging, meanwhile, the pair of cleaning rotating brushes are symmetrically installed on the two sides of the composite optical observation window, and the telescopic position is accurately controlled through a servo motor. The synchronous control technology is adopted for the rotating brush driving motors, it is guaranteed that the two cleaning rotating brushes rotate oppositely in the reverse direction at the constant speed all the time, the cleaning rotating brushes can be accurately controlled to stretch out or retract in the direction parallel to the central axis of the shell, torque is eliminated through the contra-rotating design, and the cleaning process is stable.

Description

Technical Field

[0001] This invention belongs to the field of underwater robot technology and infrastructure inspection, and particularly relates to a robotic device for detecting cracks in underwater concrete. Background Technology

[0002] The health of underwater concrete structures is directly related to the safety of major infrastructure projects such as water conservancy projects and cross-sea transportation. Cracks are one of the most common and important defects in concrete structures, requiring regular inspection. Currently, underwater inspection mainly relies on divers using handheld equipment or traditional robots for observation. The former is high-risk, costly, and inefficient; the latter is limited by the underwater environment: firstly, the water itself may be turbid, and the difference in optical refractive index between water and air can cause image distortion and blurring, affecting the accuracy of judgment; secondly, the surface of the structure is often covered with moss, shellfish, silt, and other coverings, which severely obstruct the view.

[0003] First, the underwater optical environment is complex. Light refracts, scatters, and attenuates in water, leading to severe image distortion and blurring. Even with high-performance underwater cameras, it is difficult to obtain clear images. Second, concrete surfaces accumulate various organisms and sediments in the long-term underwater environment, severely obscuring defects such as cracks that need to be detected. Existing technologies have attempted to use robotic arms for cleaning, but this is complex and easily obstructs the field of view; others use high-pressure water guns for cleaning, but this makes the water turbid, affecting subsequent imaging.

[0004] In existing technologies, some robots use high-intensity lighting and high-definition cameras to overcome turbid water, but the effect is limited. Other designs attempt to eliminate water interference by having a cover closely attached to the surface, but this does not solve the fundamental problems of cleaning surface deposits and optical distortion. Some attempts have integrated robotic arms for cleaning, but the movements are clumsy and inefficient, and the robotic arms themselves can easily obstruct the observation line of sight. Therefore, there is an urgent need for an integrated detection device that can provide a non-destructive, true, high-definition observation window and automatically complete surface cleaning. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a robotic device for underwater concrete crack detection.

[0006] This robotic device for underwater concrete crack detection includes: an external support frame, an equipment compartment, a camera, a cleaning brush, and a propulsion system. The external support frame is H-shaped. The cylindrical equipment compartment is mounted and fixed on the plane in the middle of the external support frame. One end of the equipment compartment has an opening connected to a composite optical observation window. The camera is fixed inside the equipment compartment, with its lens facing the composite optical observation window. A pair of retractable cleaning brushes are symmetrically arranged on both sides of the composite optical observation window. The composite optical observation window includes a clear water layer, a transition layer, and a vacuum layer from the inside out. The clear water layer, transition layer, and vacuum layer are separated by high-strength optical glass. The propulsion system includes a horizontal thruster and a vertical thruster. The horizontal thruster is fixed at the bottom of the plane in the middle of the external support frame, and the vertical thruster penetrates and is fixed through the plane in the middle of the external support frame. A control unit is located inside the equipment compartment, which controls the propulsion system, the cleaning brush, and the camera.

[0007] Preferably, a mounting plate is fixedly installed at the opening end of the equipment compartment, and the camera is fixed in the center of the mounting plate, with the camera facing the composite optical observation window.

[0008] Preferably, the vacuum layer is a high-vacuum and permanently sealed cavity with a vacuum level of not less than 10. 3 Pa, the inner and outer walls are made of high-strength optical glass material; the clear water layer is a water-filled sealed chamber.

[0009] As a preferred option, the sidewall of the clear water layer is provided with water injection holes, and the holes are connected by through-chamber flanges.

[0010] Preferably, a buoyancy chamber is fixed to the inner wall of the vertical sides of the external support frame, and a linear drive mechanism is fixed to the side wall of the buoyancy chamber. The cleaning brush is connected to the end of the linear drive mechanism, and the rotation axis of the cleaning brush is parallel to the central axis of the equipment compartment. The cleaning brush is designed to rotate in opposite directions.

[0011] Preferably, the overall shape of the composite optical observation window is a truncated frustum, with the inner end face diameter being smaller than the outer end face diameter.

[0012] This underwater concrete crack detection method using robotic devices includes the following steps:

[0013] Step 1: Before immersion, fill the clear water layer with water;

[0014] Step 2: Control the propulsion system to drive the robot to the underwater concrete structure surface to be inspected;

[0015] Step 3: Control the propulsion system to initially and stably press the robot's front end against the concrete structure surface;

[0016] Step 4: Activate the cleaning brush, extend it and rotate it in the opposite direction to clean the surface of the concrete structure.

[0017] Step 5: After cleaning is complete, control the cleaning brush to retract behind the vacuum layer;

[0018] Step 6: Activate the camera and use the composite optical observation window to acquire images of the cleaned surface and measure the crack width.

[0019] As a preferred option, in step one, water from the clear portion of the working water area is taken and injected into the clear water layer.

[0020] Preferably, in step four, the robot's front end is equipped with a composite optical observation window, which includes a water layer, a transition layer, and a vacuum layer from the inside out. Linear drive mechanisms are symmetrically arranged on both sides of the composite optical observation window, and the ends of the linear drive mechanisms are connected to cleaning brushes. The cleaning brushes are equipped with bristles. The linear drive mechanisms are controlled to extend the cleaning brushes so that they are positioned in front of the vacuum layer until the bristle ends of the cleaning brushes are in contact with the surface of the concrete structure, at which point the linear drive mechanisms stop extending.

[0021] The beneficial effects of this invention are:

[0022] 1) The composite optical observation window of the present invention is a three-layer optical chamber. The clear water layer is filled with water, and the water is directly taken from the clear part of the working water area to ensure the optical consistency between the clear water layer and the outside water area. This three-layer optical chamber fundamentally solves the optical distortion and blurring problems of underwater imaging and obtains clear images.

[0023] 2) The integrated rotating brush of this invention can remove surface deposits before imaging, ensuring that the observed structure itself, rather than coverings, is viewed. Simultaneously, a pair of cleaning rotating brushes are symmetrically mounted on both sides of the composite optical observation window, and their extension and retraction positions are precisely controlled by a servo motor. The rotating brush drive motor employs synchronous control technology to ensure that the two cleaning rotating brushes always rotate in opposite directions at the same speed, and the extension or retraction of the cleaning rotating brushes along a direction parallel to the central axis of the housing can be precisely controlled. This counter-rotation design eliminates torque, making the cleaning process smooth.

[0024] 3) The control module of this invention is highly integrated into the cylindrical equipment compartment, ensuring the waterproof sealing of electronic components; at the same time, it is flexible in operation, suitable for complex underwater environments, and has a compact structure with high integration. Attached Figure Description

[0025] Figure 1 This is a three-dimensional side view of the device's head.

[0026] Figure 2 This is a three-dimensional side view of the rear of the device;

[0027] Figure 3 This is a bottom view of the device;

[0028] Figure 4 This is a cross-sectional view of the composite optical observation window in the device;

[0029] Figure 5 This is a perspective view of the device performing surface cleaning operations.

[0030] Explanation of reference numerals in the attached drawings: 1. External support frame; 2. Equipment compartment; 3. Composite optical observation window; 4. Clear water layer; 5. Transition layer; 6. Vacuum layer; 7. Camera; 8. Cleaning brush; 9. Horizontal thruster; 10. Vertical thruster; 11. Buoyancy chamber; 12. Illuminator; 13. Linear drive mechanism; 14. Water injection hole; 15. High-strength optical glass. Detailed Implementation

[0031] The present invention will be further described below with reference to embodiments. The description of the embodiments below is only for the purpose of helping to understand the present invention. It should be noted that those skilled in the art can make several modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0032] Example 1

[0033] As one embodiment, a robotic device for underwater concrete crack detection is proposed, such as... Figure 1-5 As shown, it includes: an external support frame 1, an equipment compartment 2, a camera 7, a cleaning brush 8, and a propulsion system; the external support frame 1 is H-shaped; the cylindrical equipment compartment 2 is mounted and fixed on the plane in the middle of the external support frame 1; one end of the equipment compartment 2 has an opening and is connected to a composite optical observation window 3; the camera 7 is fixed inside the equipment compartment 2, and the lens of the camera 7 faces the composite optical observation window 3; a pair of retractable cleaning brushes 8 are symmetrically arranged on both sides of the composite optical observation window 3;

[0034] like Figure 4 As shown, the composite optical observation window 3 consists of a clear water layer 4, a transition layer 5, and a vacuum layer 6 from the inside out. The clear water layer 4, the transition layer 5, and the vacuum layer 6 are separated by high-strength optical glass 15. The three-layer optical chamber fundamentally solves the optical distortion and blurring problems of underwater imaging, and obtains clear images.

[0035] like Figure 1-3 As shown, the propulsion system includes horizontal thrusters 9 and vertical thrusters 10. The horizontal thrusters 9 are fixed to the bottom of the plane in the middle of the external support frame 1, and the vertical thrusters 10 are fixed through the plane in the middle of the external support frame 1. There are 4 vertical thrusters 10 located in the middle of the plane, and 2 sets of horizontal thrusters 9 are located on both sides of the plane, for a total of 4. Multiple propeller thrusters arranged in a circumferential direction provide power, enabling omnidirectional movements such as forward, backward, upward, downward, rotation, and lateral movement, and can precisely control the body attitude so that it can stably stick to the surface of the object being measured.

[0036] like Figure 1 and Figure 5As shown, the equipment compartment 2 is equipped with a control unit, which is used to control the coordinated operation of the propulsion system, the cleaning brush 8 and the camera 7. The control unit is configured to perform the following operations: control the propulsion system to bring the robot close to the surface of the object being measured; control the cleaning brush 8 to extend and perform cleaning operations; control the cleaning brush 8 to retract to the observation state; and start the camera 7 to acquire images.

[0037] like Figure 4 As shown, a fixed plate is fixedly installed at the opening end of the equipment compartment 2, and the camera 7 is fixed in the center of the fixed plate, with the camera 7 facing the composite optical observation window 3. The camera 7 is installed inside the main body, facing the center of the composite optical observation window 3. It uses a structured light depth camera in conjunction with a high-power LED illumination array to acquire high-precision three-dimensional surface information.

[0038] like Figure 1 and Figure 2 As shown, buoyancy chambers 11 are fixed to the inner walls of the vertical sides of the external support frame 1, and linear drive mechanisms 13 are fixed to the side walls of the buoyancy chambers 11. The cleaning brush 8 is connected to the end of the linear drive mechanism 13, and the rotation axis of the cleaning brush 8 is parallel to the central axis of the equipment compartment 2. The cleaning brush 8 is designed to rotate in opposite directions, with two cleaning brushes. The reverse rotation design of the cleaning brush 8 is used to counteract the torque generated during cleaning, thereby ensuring the stability of the machine. The cleaning brush 8 has two working states: Cleaning state: The cleaning brush 8 extends forward and rotates at high speed, and its bristles contact the surface of the object being measured; at the same time, the front and rear propulsion device is activated to increase the contact pressure between the brush and the concrete surface; Observation state: The cleaning brush 8 retracts backward, and its overall position is moved behind the vacuum layer 6 to avoid obstructing the field of view of the camera 7.

[0039] Example 2

[0040] As another embodiment, this second embodiment proposes, based on the first embodiment, a more specific robotic device for underwater concrete crack detection, such as... Figure 4 As shown, the composite optical observation window 3 comprises, from the inside out, a clear water layer 4, a transition layer 5, and a vacuum layer 6. The clear water layer 4 is the innermost layer, a water-filled chamber with water whose optical properties are consistent with the external water, thus initially eliminating distortion caused by refractive index differences and maintaining pressure balance and optical consistency. The transition layer 5 is the middle layer, an adjustable buffer cavity to ensure structural stability. The vacuum layer 6 is the outermost layer, a completely sealed vacuum cavity. The physical properties of vacuum completely eliminate refraction, scattering, and glare phenomena caused by light transmission in different media, providing the camera inside the equipment cabin with a lossless, ultra-high-definition observation window, as if shooting in air. The vacuum layer 6 is a high-vacuum, permanently sealed cavity with a vacuum level of not less than 10... 3Pa, the inner and outer walls are made of high-strength optical glass material to ensure its mechanical strength and optical performance; the clear water layer 4 is a water-filled sealed chamber; the side wall of the clear water layer 4 is provided with water injection holes 14, and the holes are connected by through-chamber flanges to ensure its sealing.

[0041] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiment 1 can be referred to each other, and will not be repeated in this application.

[0042] Example 3

[0043] As another embodiment, this third embodiment, based on the second embodiment, proposes an underwater concrete crack detection method using the aforementioned robotic device, such as... Figure 1-5 As shown, it includes the following steps:

[0044] Step 1: Before entering the water, fill the clear water layer 4 with water; specifically, take water from the clear part of the working area and inject it into the clear water layer 4 to ensure the optical consistency between the clear water layer 4 and the outside water area; the vacuum layer 6 has been vacuumed and permanently sealed on the shore, and no underwater operation is required.

[0045] Step 2: Control the propulsion system to drive the robot to the underwater concrete structure surface to be inspected;

[0046] Step 3: Control the propulsion system to initially and stably press the robot's front end against the concrete structure surface;

[0047] Step 4: Activate the cleaning brush 8, extending it and rotating it in the opposite direction to clean the surface of the concrete structure of any adhering substances; specifically, as shown... Figure 1-4 As shown, the front end of the robot is provided with a composite optical observation window 3. The composite optical observation window 3 includes a water layer 4, a transition layer 5 and a vacuum layer 6 from the inside to the outside. Linear drive mechanisms 13 are symmetrically arranged on both sides of the composite optical observation window 3. The ends of the linear drive mechanisms 13 are connected to cleaning brushes 8. The cleaning brushes 8 are provided with bristles. The linear drive mechanisms 13 are controlled to extend the cleaning brushes 8 so that the cleaning brushes 8 are in front of the vacuum layer 6 until the bristle ends of the cleaning brushes 8 are in contact with the surface of the concrete structure, and then the linear drive mechanisms 13 stop extending.

[0048] The control unit issues a command, and the linear drive mechanism 13 pushes the two cleaning brushes 8 forward so that their bristles contact the surface of the object being tested; then, the motors of the two cleaning brushes 8 start and rotate at high speed in opposite directions to brush away the adhering substances on the surface; the torque generated by the opposite rotation cancels each other out, and the machine body does not spin.

[0049] Step 5: After cleaning is complete, control the cleaning brush 8 to retract to behind the vacuum layer 6;

[0050] Step 6: Activate camera 7 to acquire images and measure crack width on the cleaned surface through composite optical observation window 3; specifically, light shines through vacuum layer 6 onto the freshly cleaned concrete surface and returns image data, which is recorded by the control system or transmitted back to the water surface station for analysis, thereby accurately identifying cracks; after image acquisition is completed, the vacuum state is released, the robot detaches from the measured surface, and is ready for the next operation or retrieval.

[0051] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiment 2 can be referred to each other, and will not be repeated in this application.

[0052] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

Claims

1. A robotic device for underwater concrete crack detection, characterized in that, include: The system comprises an external support frame, an equipment compartment, a camera, cleaning brushes, and a propulsion system. The external support frame is H-shaped. The cylindrical equipment compartment is mounted and fixed on the plane in the middle of the external support frame. One end of the equipment compartment has an opening connected to a composite optical observation window. The camera is fixed inside the equipment compartment, with its lens facing the composite optical observation window. A pair of retractable cleaning brushes are symmetrically arranged on both sides of the composite optical observation window. The composite optical observation window, from the inside out, includes a clean water layer, a transition layer, and a vacuum layer. The clean water layer, transition layer, and vacuum layer are separated by high-strength optical glass. The propulsion system includes a horizontal thruster and a vertical thruster. The horizontal thruster is fixed at the bottom of the plane in the middle of the external support frame, and the vertical thruster penetrates and is fixed through the plane in the middle of the external support frame. A control unit is located inside the equipment compartment, which controls the propulsion system, cleaning brushes, and camera.

2. The robotic device for underwater concrete crack detection according to claim 1, characterized in that, A mounting plate is fixedly installed at the opening end of the equipment compartment, and the camera is fixed in the center of the mounting plate, facing the composite optical observation window.

3. The robotic device for underwater concrete crack detection according to claim 1, characterized in that, The vacuum layer is a high-vacuum, permanently sealed cavity with a vacuum level of not less than 10. 3 Pa, the inner and outer walls are made of high-strength optical glass material; the clear water layer is a water-filled sealed chamber.

4. The robotic device for underwater concrete crack detection according to claim 1, characterized in that, The side wall of the clear water layer is equipped with water injection holes, and the holes are connected by through-chamber flanges.

5. The robotic device for underwater concrete crack detection according to claim 1, characterized in that, Buoyancy chambers are fixed to the inner walls of the vertical sides of the external support frame. Linear drive mechanisms are fixed to the side walls of the buoyancy chambers. The cleaning brush is connected to the end of the linear drive mechanism. The rotation axis of the cleaning brush is parallel to the central axis of the equipment compartment. The cleaning brush is designed to rotate in the opposite direction.

6. The robotic device for underwater concrete crack detection according to claim 1, characterized in that, The overall shape of the composite optical observation window is a truncated frustum, with the diameter of its inner end face being smaller than that of its outer end face.

7. A method for detecting underwater concrete cracks using the robotic device as described in claim 1, characterized in that, Includes the following steps: Step 1: Before immersion, fill the clear water layer with water; Step 2: Control the propulsion system to drive the robot to the underwater concrete structure surface to be inspected; Step 3: Control the propulsion system to initially and stably press the robot's front end against the concrete structure surface; Step 4: Activate the cleaning brush, extend it and rotate it in the opposite direction to clean the surface of the concrete structure. Step 5: After cleaning is complete, control the cleaning brush to retract behind the vacuum layer; Step 6: Activate the camera and use the composite optical observation window to acquire images of the cleaned surface and measure the crack width.

8. The underwater concrete crack detection method according to claim 7, characterized in that, In step one, take water from the clear part of the working area and inject it into the clear water layer.

9. The underwater concrete crack detection method according to claim 7, characterized in that, In step four, the robot's front end is equipped with a composite optical observation window, which includes a water layer, a transition layer, and a vacuum layer from the inside out. Linear drive mechanisms are symmetrically arranged on both sides of the composite optical observation window, and the ends of the linear drive mechanisms are connected to cleaning brushes. The cleaning brushes are equipped with bristles. The linear drive mechanisms are controlled to extend the cleaning brushes so that they are positioned in front of the vacuum layer until the bristle ends of the cleaning brushes are in contact with the surface of the concrete structure, at which point the linear drive mechanisms stop extending.

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