An unmanned aerial vehicle-based outer wall crack detection device

Abstract

The utility model provides a kind of outer wall crack detection device based on unmanned plane, including unmanned plane body, the middle part fixedly connected with placing plate of unmanned plane body support frame, the side fixedly connected with fixed strip of placing plate, the outside of fixed strip is provided with stretch strip, telescopic component is arranged between fixed strip and stretch strip, the outside fixed mounting of stretch strip has detection box body, laser range finder is fixedly installed at the four corners of detection box body, the outside fixedly connected with optical camera of detection box body middle part. By the telescopic adjusting structure of double-shaft motor and screw rod multiple telescopic strips, the detection box body can be telescoped in a large range, it can also be in-depth arc outer wall inner side, building narrow gap and other traditional detection difficult to reach area, and it can also be aligned to tiny crack by fine adjustment of gear rack, solve the problem of missing detection of arc outer wall, high corner and other scenes, and the detection coverage is extensive.

Description

Technical Field

[0001] This utility model relates to the field of building structure inspection technology, specifically to an external wall crack detection device based on a drone. Background Technology

[0002] In the field of building operation and safety inspection, the detection of external wall cracks in tall structures such as high-rise buildings, bridges, and dams is a crucial step in ensuring structural safety. With the acceleration of urbanization, the number of such structures has surged. Their external walls are exposed to the natural environment for extended periods, making them susceptible to cracks due to factors such as temperature cycles, wind and rain erosion, and foundation settlement. To avoid the risks associated with manual high-altitude inspections, some inspections utilize ordinary drones equipped with cameras for aerial photography, followed by image analysis to identify cracks. However, cameras in this method are often fixed to the bottom or side of the drone, making it impossible to flexibly adjust the distance and shooting angle from the external wall according to inspection needs. For curved external walls, narrow crack areas, or high-altitude blind spots, it is difficult to obtain clear images, easily leading to missed cracks. Utility Model Content

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide an external wall crack detection device based on unmanned aerial vehicles (UAVs) to solve the problems mentioned in the background. This invention features a novel structure. Through the telescopic adjustment structure of a dual-axis motor and multiple sets of telescopic bars on a screw, the detection box can be extended and retracted over a wide range. It can reach areas that are difficult to access with traditional methods, such as the inner side of curved external walls and narrow building gaps. Furthermore, it can precisely target tiny cracks through the fine adjustment of gears and racks, solving the problem of missed detection in scenarios such as curved external walls and high-altitude blind spots. The detection coverage is extensive.

[0004] To achieve the above objectives, this utility model is implemented through the following technical solution: a drone-based external wall crack detection device, comprising a drone body, a placement plate fixedly connected to the middle of the drone body support frame, a fixing strip fixedly connected to one side of the placement plate, an extension strip provided on the outer side of the fixing strip, a telescopic component provided between the fixing strip and the extension strip, a detection box fixedly installed on the outer side of the extension strip, laser rangefinders fixedly installed at the four corners of the detection box, an optical camera fixedly connected to the outer side of the middle of the detection box, and a ring-shaped supplementary light fixedly connected to the outer side of the detection box surrounding the optical camera.

[0005] Furthermore, a dual-axis motor is fixedly installed on the upper side of the middle part of the fixing strip, and the ends of the output shafts at both ends of the dual-axis motor are fixedly connected with screws with opposite threads. Adjusting blocks are slidably fitted on both sides above the fixing strip.

[0006] Furthermore, a limiting groove is transversely opened in the middle of the two adjusting blocks, and an internal threaded sleeve is slidably fitted on the inner wall of the limiting groove. Both ends of the internal threaded sleeve are fixedly connected to limiting rings that abut against the two outer sides of the adjusting blocks. The two internal threaded sleeves are respectively fitted on the screws on both sides and threadedly fitted with them. A buffer spring is fixedly connected between the outer end of the internal threaded sleeve and the outer side of the adjusting block.

[0007] Furthermore, a first through groove is provided through the middle of the fixing strip, and first connecting brackets are provided on both sides of the inner wall of the first through groove. A first rotating connecting shaft is rotatably engaged at the intersection of the two first connecting brackets.

[0008] Furthermore, both sides of the upper and lower inner walls of the first through groove are provided with first strip grooves extending outwards, and the bottom of each of the two adjusting blocks is fixedly connected with a first connecting post that rotates and slides with the inner walls of the first strip grooves on both sides. The two first connecting posts are respectively rotated with one end of the two first connecting frames.

[0009] Furthermore, the telescopic assembly includes multiple telescopic bars disposed between the fixed bar and the extension bar, and a second through groove is provided through the middle of each of the multiple telescopic bars. Second connecting frames are provided on both sides of the inner wall of the second through groove, and a second rotating connecting shaft is rotatably engaged at the intersection of the middle positions of the two second connecting frames.

[0010] Furthermore, displacement blocks are provided on both sides above the telescopic strip, and centrally symmetrical racks are fixedly connected to the opposite sides of the two displacement blocks. A gear is rotatably engaged on the upper side of the middle of the telescopic strip. The gear is located between the two racks and meshes with them. A second strip-shaped groove is provided on both sides of the upper and lower inner walls of the second through groove.

[0011] Furthermore, the bottom of each of the two displacement blocks is fixedly connected to a second connecting post that rotates and slides with the inner wall of the second strip groove on both sides. The two second connecting posts are respectively rotated with one end of the two second connecting frames, and the two ends of the two first connecting frames near the telescopic strip are respectively rotated with the two second connecting posts.

[0012] The beneficial effects of this utility model are:

[0013] 1. This drone-based exterior wall crack detection device uses a dual-axis motor and a screw with multiple telescopic adjustment bars to achieve a wide range of expansion and contraction of the detection box. It can reach areas that are difficult to access with traditional detection methods, such as the inner side of curved exterior walls and narrow building gaps. It can also be precisely adjusted by gears and racks to target tiny cracks, solving the problem of missed detection in scenarios such as curved exterior walls and high-altitude blind spots. The detection coverage is extensive.

[0014] 2. This drone-based exterior wall crack detection device monitors the distance in real time using a laser rangefinder to ensure that the optical camera is always at the optimal shooting distance, avoiding image blurring caused by distance deviation; the ring-shaped supplementary light eliminates light interference and ensures clear crack details; the buffer spring reduces the impact of vibration and collision, further improving image stability. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the telescopic component of this utility model when it is deployed on the drone body;

[0016] Figure 2 This is a schematic diagram of the telescopic component of this utility model when it is retracted onto the drone body;

[0017] Figure 3 This is a schematic diagram of the structure of the detection box of this utility model;

[0018] Figure 4 This is a schematic diagram of the connection between the fixing strip and the telescopic component of this utility model;

[0019] Figure 5 This is a side sectional view of the adjusting block portion of this utility model.

[0020] Figure 6 This is a schematic diagram of the structure of the telescopic component of this utility model;

[0021] Figure 7 This utility model Figure 6 - Enlarged structural diagram at point A.

[0022] In the diagram: 1. UAV body; 2. Placement plate; 3. Fixing strip; 4. Extension strip; 5. Telescopic assembly; 501. Telescopic strip; 502. Second through groove; 503. Second connecting frame; 504. Second rotating connecting shaft; 505. Displacement block; 506. Rack; 507. Gear; 508. Second strip groove; 509. Second connecting post; 6. Detection box; 7. Laser rangefinder; 8. Optical camera; 9. Ring fill light; 11. Dual-axis motor; 12. Screw; 13. Adjusting block; 14. First through groove; 15. First connecting frame; 16. First rotating connecting shaft; 17. First strip groove; 18. First connecting post; 20. Limiting groove; 21. Threaded sleeve; 22. Buffer spring. Detailed Implementation

[0023] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0024] Please refer to Figures 1 to 7This utility model provides a technical solution: an external wall crack detection device based on a drone, including a drone body 1, a placement plate 2 fixedly connected to the middle of the support frame of the drone body 1, a fixing strip 3 fixedly connected to one side of the placement plate 2, an extension strip 4 provided on the outer side of the fixing strip 3, a telescopic component 5 provided between the fixing strip 3 and the extension strip 4, a detection box 6 fixedly installed on the outer side of the extension strip 4, laser rangefinders 7 fixedly installed at the four corners of the detection box 6, an optical camera 8 fixedly connected to the outer side of the middle of the detection box 6, and a ring-shaped supplementary light 9 fixedly connected to the outer side of the detection box 6 surrounding the optical camera 8.

[0025] In this embodiment, a dual-axis motor 11 is fixedly installed on the upper side of the middle part of the fixing strip 3. The ends of the output shafts at both ends of the dual-axis motor 11 are fixedly connected to screws 12 with opposite threads. Adjusting blocks 13 are slidably fitted on both sides above the fixing strip 3. Limiting grooves 20 are transversely opened through the middle of the two adjusting blocks 13. Internal threaded sleeves 21 are slidably fitted on the inner wall of the limiting grooves 20. Limiting rings that abut against the two outer sides of the adjusting blocks 13 are fixedly connected to both ends of the internal threaded sleeves 21. The two internal threaded sleeves 21 are respectively fitted on the screws 12 on both sides and threadedly fitted with them. The outer ends of the internal threaded sleeves 21 are connected to the adjusting blocks 13. A buffer spring 22 is fixedly connected between the outer sides of the two adjusting blocks 13. A first through groove 14 is opened through the middle of the fixing strip 3. A first connecting frame 15 is arranged crosswise on both sides of the inner wall of the first through groove 14. A first rotating connecting shaft 16 is rotatably engaged at the cross position of the two first connecting frames 15. A first strip groove 17 is opened outward on both sides of the upper and lower inner walls of the first through groove 14. A first connecting post 18 is fixedly connected to the bottom of the two adjusting blocks 13 and rotates and slides with the inner wall of the first strip groove 17 on both sides. The two first connecting posts 18 are rotatably engaged with one end of the two first connecting frames 15 respectively.

[0026] Specifically, when it is necessary to adjust the distance between the detection box 6 and the outer wall, the dual-axis motor 11 on the upper side of the fixing strip 3 is activated. The output shafts at both ends of the dual-axis motor 11 drive the screws 12 with opposite threads to rotate synchronously. Since the internal thread sleeve 21 is threadedly engaged with the screw 12, and the internal thread sleeve 21 is slidably connected through the limiting groove 20 of the adjusting block 13 (the limiting rings at both ends of the internal thread sleeve 21 prevent it from disengaging from the adjusting block 13), the rotation of the screw 12 will drive the two internal thread sleeves 21 to move in opposite directions along the axial direction (one side is closer to the dual-axis motor 11, and the other side is away from the dual-axis motor 11). When the internal thread sleeve 21 moves, the buffer spring 22 pushes the adjusting block 13 to slide along the fixing strip 3. The first connecting post 18 at the bottom of the adjusting block 13 slides in the first strip groove 17 of the fixing strip 3, and drives the first connecting frame 15, which is cross-shaped in the first through groove 14, to rotate around the first rotating connecting shaft 16. The first connecting frame 15, near the telescopic component 5, rotates in conjunction with the second connecting post 509 of the telescopic bar 501, thereby pushing multiple sets of telescopic bars 501 to extend or retract through the cross rotation of the second connecting frame 503 (around the second rotating connecting shaft 504), ultimately causing the extension bar 4 and the outer detection box 6 to move closer to or further away from the outer wall, thus achieving a wide range of adjustment of the detection distance.

[0027] In this embodiment, the telescopic assembly 5 includes multiple telescopic bars 501 disposed between the fixed bar 3 and the extension bar 4. A second through groove 502 is formed through the middle of each of the multiple telescopic bars 501. Second connecting brackets 503 are arranged crosswise on both sides of the inner wall of the second through groove 502. A second rotating connecting shaft 504 is rotatably engaged at the intersection of two second connecting brackets 503. Displacement blocks 505 are provided on both sides above each telescopic bar 501. A centrally symmetrical rack 506 is fixedly connected to the opposite sides of each of the two displacement blocks 505. The telescopic bar 501 has a centrally symmetrical rack 506. A gear 507 is rotatably engaged on the upper side. The gear 507 is located between and meshes with two racks 506. The upper and lower inner walls of the second through groove 502 are provided with second strip-shaped grooves 508 extending outward from both sides. The bottom of each of the two displacement blocks 505 is fixedly connected with a second connecting post 509 that rotatably and slidably engages with the inner walls of the second strip-shaped grooves 508 on both sides. The two second connecting posts 509 are rotatably engaged with one end of each of the two second connecting frames 503. The two ends of the two first connecting frames 15 near the telescopic strip 501 are rotatably engaged with the two second connecting posts 509 respectively.

[0028] Specifically, if further fine-tuning of the position of the detection box 6 is needed to align with the crack, the gear 507 on the upper side of the telescopic bar 501 can be driven to rotate. The gear 507 meshes with the racks 506 of the two side displacement blocks 505. When the gear 507 rotates, it drives the racks 506 and the displacement blocks 505 to slide in the opposite direction along the telescopic bar 501. The second connecting post 509 at the bottom of the displacement block 505 slides in the second strip groove 508, pushing the second connecting frame 503 to rotate around the second rotating connecting shaft 504, adjusting the spacing between adjacent telescopic bars 501, achieving millimeter-level fine positioning of the detection box 6, and ensuring that the optical camera 8 is accurately aligned with the crack area.

[0029] When using the device, the detection box 6 is placed close to the outer wall to obtain a clear image. A command is sent through the ground terminal to start the dual-axis motor 11 on the fixing bar 3. The output shafts at both ends of the dual-axis motor 11 drive the screws 12 with opposite threads to rotate synchronously. The internal thread sleeve 21, which is threaded with the screw 12, slides in the opposite direction along the limiting groove 20 of the adjusting block 13. The buffer spring 22 pushes the adjusting block 13 to move along the fixing bar 3. The first connecting post 18 at the bottom of the adjusting block 13 slides in the first strip groove 17, causing the first connecting frame 15 in the first through groove 14 to rotate around the first rotating connecting shaft 16, thereby pushing the multiple sets of telescopic bars 501 of the telescopic assembly 5 through the second connecting... The cross-rotation extension of frame 503 (around the second rotating connecting shaft 504) causes the extension bar 4 to gradually move the detection box 6 closer to the outer wall. During this process, the distance is monitored in real time by the laser rangefinder 7. When the distance reaches 5-10cm (the optimal shooting distance of the optical camera 8), the operation of the dual-axis motor 11 is paused. If further fine-tuning of the position of the detection box 6 is needed to align with the suspected crack area, the gear 507 on the telescopic bar 501 is driven to rotate. The gear 507 meshes with the rack 506 of the displacement blocks 505 on both sides, causing the displacement blocks 505 to slide along the telescopic bar 501. The second connecting post 509 at the bottom of the displacement block 505 moves within the second strip groove 508. The second connecting bracket 503 is pushed to fine-tune the spacing between adjacent telescopic strips 501, achieving millimeter-level positioning of the detection box 6 and ensuring that the optical camera 8 is accurately aligned with the crack. Then, the data acquisition phase begins: Observe the ambient light conditions. If it is cloudy, dusk, or in a shadowed area of ​​the exterior wall, turn on the ring light 9 surrounding the optical camera 8 and adjust it to a suitable brightness to eliminate shadows and reflections on the exterior wall surface. Control the optical camera 8 to start continuous shooting mode, acquiring high-definition images of the crack (including the overall shape and local details of the crack). Simultaneously, the laser rangefinder 7 continuously collects distance data between the detection box 6 and the exterior wall, ensuring stable distance during shooting (avoiding slight shaking of the drone). (If the movement causes the image to become blurry). If multiple crack areas need to be detected, repeat the above telescopic adjustment steps, operate the drone body 1 to move slowly, and adjust the position of the detection box 6 through the telescopic component 5 to complete the image acquisition of different areas in sequence. During the detection process, the image data captured by the optical camera 8 and the distance data of the laser rangefinder 7 will be transmitted to the ground terminal in real time through the wireless module. The staff can check the image clarity on site. If the image of a certain area is found to be blurry (such as due to the vibration of the detection box 6 caused by airflow), the buffer spring 22 will absorb some of the vibration energy. At the same time, the attitude of the drone body 1 or the position of the detection box 6 can be finely adjusted through the ground terminal to re-acquire the image.After all target areas have been inspected, the dual-axis motor 11 is reversed, causing the telescopic component 5 to retract. The inspection box 6 retracts along with the extension bar 4 to a position close to the drone body 1. The ring light 9 is turned off, and the drone body 1 is controlled to return to its home position. After the drone lands smoothly, the equipment power is turned off, and the collected crack image data is imported into the analysis software for precise measurement of parameters such as crack width and length, and report generation, completing the entire external wall crack inspection workflow.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It is obvious to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model.

[0031] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A device for detecting external wall cracks based on unmanned aerial vehicles (UAVs), comprising a UAV body (1), characterized in that: A placement plate (2) is fixedly connected to the middle of the support frame of the UAV body (1). A fixing strip (3) is fixedly connected to one side of the placement plate (2). An extension strip (4) is provided on the outside of the fixing strip (3). A telescopic component (5) is provided between the fixing strip (3) and the extension strip (4). A detection box (6) is fixedly installed on the outside of the extension strip (4). A laser rangefinder (7) is fixedly installed at each of the four corners of the detection box (6). An optical camera (8) is fixedly connected to the outside of the middle of the detection box (6). A ring-shaped supplementary light (9) is fixedly connected to the outside of the detection box (6) surrounding the optical camera (8).

2. The external wall crack detection device based on UAV according to claim 1, characterized in that: A dual-axis motor (11) is fixedly installed on the upper side of the middle part of the fixing strip (3). The ends of the output shafts at both ends of the dual-axis motor (11) are fixedly connected to screws (12) with opposite threads. Adjusting blocks (13) are slidably fitted on both sides above the fixing strip (3).

3. The external wall crack detection device based on UAV according to claim 2, characterized in that: A limiting groove (20) is opened horizontally through the middle of the two adjusting blocks (13). The inner wall of the limiting groove (20) is slidably fitted with an internal thread sleeve (21). Both ends of the internal thread sleeve (21) are fixedly connected with limiting rings that abut against the two outer sides of the adjusting block (13). The two internal thread sleeves (21) are respectively fitted on the screws (12) on both sides and threadedly fitted with them. A buffer spring (22) is fixedly connected between the outer end of the internal thread sleeve (21) and the outer side of the adjusting block (13).

4. The external wall crack detection device based on a drone according to claim 3, characterized in that: The fixing strip (3) has a first through groove (14) through the middle. The inner wall of the first through groove (14) is provided with first connecting frames (15) arranged in a cross arrangement on both sides. The two first connecting frames (15) are rotatably connected to a first rotating connecting shaft (16) at the cross position in the middle.

5. The external wall crack detection device based on a drone according to claim 4, characterized in that: The first through groove (14) has a first strip groove (17) extending outward on both sides of the upper and lower inner walls. The bottom of the two adjustment blocks (13) is fixedly connected to a first connecting post (18) that rotates and slides with the inner walls of the first strip groove (17) on both sides. The two first connecting posts (18) are respectively rotated with one end of the two first connecting frames (15).

6. The external wall crack detection device based on a drone according to claim 5, characterized in that: The telescopic assembly (5) includes multiple telescopic bars (501) disposed between the fixed bar (3) and the extension bar (4). A second through groove (502) is provided through the middle of each of the multiple telescopic bars (501). Second connecting frames (503) are provided on both sides of the inner wall of the second through groove (502) and are arranged in a cross manner. A second rotating connecting shaft (504) is rotatably engaged at the cross position of the two second connecting frames (503).

7. The external wall crack detection device based on a drone according to claim 6, characterized in that: The telescopic strip (501) has displacement blocks (505) on both sides above it. The two displacement blocks (505) are fixedly connected to the opposite sides of the racks (506) which are centrally symmetrical. The upper side of the middle part of the telescopic strip (501) is rotatably fitted with a gear (507). The gear (507) is located between the two racks (506) and meshes with them. The upper and lower inner walls of the second through groove (502) are provided with second strip grooves (508) extending outward from both sides.

8. The external wall crack detection device based on a drone according to claim 7, characterized in that: The bottom of each of the two displacement blocks (505) is fixedly connected to a second connecting post (509) that rotates and slides with the inner wall of the second strip groove (508) on both sides. The two second connecting posts (509) are respectively rotated with one end of the two second connecting frames (503). The two ends of the two first connecting frames (15) near the telescopic strip (501) are respectively rotated with the two second connecting posts (509).

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