Highway subgrade high slope displacement monitoring device and method based on unmanned aerial vehicle

Abstract

The application discloses a kind of highway subgrade high slope displacement monitoring device and method based on unmanned plane, including unmanned plane with unmanned plane airborne monitoring subsystem and slope surface target point assembly, slope surface target point assembly includes limiting box in slope surface and outer sleeve inserted into soil inside;Rotary mounting is rotated in the top circular cavity of limiting box by the rotation of flap driven by the flight air current of unmanned plane, the bottom of rotating flap is detachably connected with installation round plate, and the installation cavity with target plate embedded in the inside is opened in the bottom of installation round plate;Inner cylinder is slidably connected in outer sleeve, and inverted conical block, connecting block, plugging head and fixed tip are sequentially fixed and installed in the bottom of inner cylinder, a plurality of metal framework pieces are integrally formed in the bottom of outer sleeve, a plurality of limiting bottom plates filled in the gap of metal framework piece are fixed and installed in the top of plugging head, solve the problem that monitoring target anchoring stability is insufficient in soft matrix slope, and field target disc surface protection operation is not convenient.

Description

Technical Field

[0001] This invention belongs to the field of road slope safety monitoring, and relates to a device and method for monitoring the displacement of high slopes of highway subgrade based on unmanned aerial vehicles (UAVs). Background Technology

[0002] High slopes along highway subgrades are mostly located in mountainous and hilly areas. Affected by factors such as rainfall seepage, traffic load disturbances, and changes in geological conditions, these slopes are prone to surface slippage, settlement, and other deformation phenomena. Continuous monitoring of slope displacement dynamics is a crucial aspect of ensuring road operational safety. With the development of UAV remote sensing and photogrammetry technologies, displacement observation methods relying on airborne acquisition equipment in conjunction with fixed targets on the slope surface have been widely applied in the daily inspection of long-distance slopes.

[0003] Currently, slope monitoring targets are mostly fixed using ordinary rods or expansion anchors. However, in soft soil slope conditions, the soil's cohesion and shear strength are low. After rainfall softens the soil, the frictional force between the soil and the rod decreases significantly, making the rod prone to shifting along with the surface soil or being pulled out entirely. This leads to inaccurate benchmark positions of the observation points, directly affecting the accuracy of displacement measurements. Conventional expansion anchors can only achieve a single tightening fixation during installation and cannot actively adjust their anchoring performance as slope slippage progresses. In slope environments with continuous deformation trends, their long-term reliability is limited.

[0004] Furthermore, since the monitoring targets are deployed in open-air environments for extended periods, the identification panels are directly exposed to the elements, resulting in a gradual decrease in reflectivity and feature recognition accuracy over time due to dust accumulation, rain erosion, and ultraviolet radiation. Some target devices with protective structures require manual on-site operation for opening and closing, which is incompatible with the remote inspection mode of drones. If an electrically driven protective structure is used, a power supply unit and control module are required, increasing the deployment procedures and maintenance costs in the field. Moreover, the stability of the device's operation is heavily dependent on the power supply conditions. Summary of the Invention

[0005] In view of this, in order to solve the problems of insufficient anchoring stability of monitoring targets in soft matrix slopes and inconvenient operation and maintenance of field target protection, resulting in poor performance, the present invention provides a UAV-based device and method for monitoring displacement of high slopes of highway subgrade.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A UAV-based highway subgrade high slope displacement monitoring device includes a UAV equipped with an airborne monitoring subsystem and a slope target measuring point assembly. The slope target measuring point assembly includes a limiting box located on the slope surface and an outer sleeve inserted into the soil. The limiting box has a circular cavity at the top, and a rotating flap driven by the airflow of the UAV is rotatably installed inside the circular cavity. The bottom of the rotating flap is detachably connected to an installation circular plate, and the bottom of the installation circular plate has an installation cavity in which a target plate is fixedly embedded. An inner cylinder is slidably connected inside the outer sleeve. An inverted conical block, a connecting block, a sealing head, and a fixing tip are fixedly installed sequentially at the bottom of the inner cylinder. Multiple metal skeleton pieces are integrally formed at the bottom of the outer sleeve. Multiple limiting base plates that fill the gaps between the metal skeleton pieces are fixedly installed at the top of the sealing head. Side arc-shaped blocks are fixedly installed on the inner wall of the metal skeleton pieces. A support block II for supporting the side arc-shaped blocks in the initial position is fixedly installed at the top of the limiting base plate.

[0008] A method for monitoring displacement of high slopes of highway subgrade based on unmanned aerial vehicles (UAVs), employing the monitoring device described above, includes the following steps:

[0009] S1. Baseline layout and point pre-embedding: Set up ground reference substations in the stable area around the slope, drive the outer sleeve and inner sleeve into the predetermined position on the slope, push the inner sleeve down to make the metal skeleton plate expand to complete the initial anchoring, screw the limit box into the top of the outer sleeve to complete the target measurement point layout, collect the initial coordinates of each measurement point and build the slope reference model and store it in the background management and control subsystem.

[0010] S2. Inspection route planning: The background control subsystem plans the UAV's autonomous inspection route based on the slope range and the location of the measuring points, and sets the hovering observation position and flight parameters for each measuring point.

[0011] S3. Airborne data acquisition: The UAV flies autonomously along a preset route. The airborne RTK rover receives differential signals from the ground reference substation to obtain high-precision pose. The high-definition fixed-focus industrial camera and miniature lidar simultaneously acquire slope images and point cloud data. When the UAV approaches the measurement point, the downdraft drives the rotating flap to open, revealing the target plate to complete the fixed-point shooting.

[0012] S4. Initial displacement judgment at the airborne end: The airborne processing unit identifies the target plate in the acquired image and calculates the current coordinates of the measurement point. It compares the current coordinates with the initial reference coordinates to obtain the displacement. If the displacement exceeds the preset threshold, it transmits the early warning information back to the background control subsystem through the wireless data transmission module.

[0013] S5. Background fine processing and analysis: After the drone returns, it uploads the complete data to the background control subsystem. The background control subsystem performs data splicing and registration processing to generate a current slope 3D model. It then performs a full-domain deformation comparison analysis with the benchmark model to obtain the full slope displacement distribution results.

[0014] S6. Data archiving and early warning output: The background management subsystem stores the current monitoring data and generates monitoring reports. It classifies early warning levels according to displacement and displacement rate, and pushes corresponding early warning information through the early warning output module.

[0015] The beneficial effects of this invention are as follows:

[0016] 1. The UAV-based highway subgrade high slope displacement monitoring device disclosed in this invention achieves slope anchoring through the cooperative structure of an outer sleeve and an inner sleeve. During installation, the inner sleeve is pushed downwards, causing the inverted conical block to move downwards synchronously, pushing multiple metal skeleton plates to expand outwards. The serrated ends of the metal skeleton plates can cut into the surrounding soil, forming a stable interlocking effect and completing the initial anchoring. When the surface soil of the slope shows a tendency to slide, the outer sleeve also shows a tendency to displace along with the surface soil. The inner sleeve and the inverted conical block remain relatively stationary because they are anchored in a deep stable soil layer. The relative displacement between the outer sleeve and the inner sleeve causes the inverted conical block to further expand the metal skeleton plates, increasing the anchoring contact area and enhancing the soil interlocking effect. The stronger the slope sliding tendency, the greater the expansion amplitude of the metal skeleton plates, and the anchoring resistance increases synchronously, forming a self-reinforcing anchoring characteristic. This can adapt to the working conditions of soft matrix slopes, ensure the long-term stability of the target point benchmark, and improve the reliability of displacement observation data.

[0017] 2. The UAV-based highway subgrade high slope displacement monitoring device disclosed in this invention features a rotatable flap on the top of the limiting box, with a target plate mounted below it via a mounting circular plate. In non-inspection mode, the flap covers the top opening of the circular cavity, blocking external dust, rain, and direct sunlight from affecting the target plate and maintaining the stability of the disc's recognition performance. When the UAV approaches the location for observation, its downward airflow enters the air duct through the inclined air inlet slot. The airflow pressure pushes the piston plate to produce lateral displacement. Through the transmission of the connecting plate, rack, drive gear, and driven gear, it drives the rotating shaft I to rotate, thereby causing the flap to flip downwards, exposing the target plate for onboard acquisition equipment to capture and identify. The entire opening and closing process requires no additional electronic control components or independent power supply unit; it is automatically triggered by the airflow during UAV operation, naturally synchronizing with the inspection process and reducing the procedures and maintenance investment required for field deployment.

[0018] 3. The UAV-based highway subgrade high slope displacement monitoring device disclosed in this invention uses a sealing head that engages with the bottom of a metal skeleton plate. During the initial insertion into the soil layer, the insertion block is embedded inside the vertical hole, and the outer limiting plate and support block II constrain the side arc-shaped block, keeping the multiple metal skeleton plates in a closed state and preventing premature expansion during insertion, which would affect the smoothness of the insertion. After insertion, the inner cylinder moves downward, and the sealing head moves downward simultaneously to release the constraint on the metal skeleton plate, ensuring that the expansion process proceeds in an orderly manner. At the same time, the fixed tip at the bottom of the sealing head penetrates into the deep soil layer, further strengthening the anchoring foundation of the inner cylinder and improving the pull-out resistance of the overall structure.

[0019] 4. The UAV-based highway subgrade high slope displacement monitoring device disclosed in this invention has a slope target measuring point component that works in conjunction with a ground reference substation, a UAV airborne monitoring subsystem, and a background control subsystem. The stable anchoring structure provides a reliable point reference for displacement calculation, and the automatically opening and closing protective structure ensures that the target plate maintains a clear identification effect over a long period of time. Both of these components together improve the data accuracy and device operation stability during long-term monitoring, making it suitable for the long-term field deployment needs of highway high slopes.

[0020] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0022] Figure 1 This is a three-dimensional structural diagram of the cooperation between the drone and the limiting box in this invention;

[0023] Figure 2 This is a three-dimensional structural diagram of the limiting box in this invention;

[0024] Figure 3 This is a three-dimensional structural diagram of the outer sleeve and the limiting box in this invention;

[0025] Figure 4 This is an exploded view of the inner cylinder and outer cylinder in this invention;

[0026] Figure 5 This is a three-dimensional structural diagram of the outer sleeve in this invention;

[0027] Figure 6 This is a three-dimensional structural diagram of the inner cylinder and the fixed tip in this invention;

[0028] Figure 7 This is an exploded structural diagram of the rotating flap and the limiting box in this invention;

[0029] Figure 8 This is a three-dimensional sectional view of the limiting box in this invention;

[0030] Figure 9 This is a three-dimensional structural diagram of the connecting plate and the rotating flap in this invention;

[0031] Figure 10 This is an exploded view of the rotating flap and target plate in this invention.

[0032] Reference numerals: 1. UAV; 2. Rotating flap; 3. Limiting box; 4. Sloping air inlet slot; 5. Outer sleeve; 6. Fixed tip; 7. Mounting slot; 8. Internal threaded block; 9. Arc surface; 10. Sliding groove; 11. Inner cylinder; 12. Sliding block; 13. Inverted conical block; 14. Connecting block; 15. Sealing head; 16. Rubber pad; 17. Side arc block; 18. Vertical hole; 19. Conical surface; 20. Serrated end; 21. Metal frame piece; 22. Arc surface; 23. Limiting base plate; 24. Insert 25. Connecting block; 26. Support block II; 27. Outer limiting plate; 28. Sliding horizontal plate; 29. ​​Circular cavity; 20. Support block I; 31. Rubber ring; 32. Vertical groove; 33. Horizontal groove; 34. Circular hole; 35. Driven gear; 36. Rotating shaft I; 37. Rotating shaft II; 38. Drive gear; 39. Compression spring; 40. Air duct; 41. Rack; 42. Connecting plate; 43. Piston plate; 44. Mounting circular plate; 45. Threaded hole; 46. Annular outer groove; 47. Mounting cavity; 48. Target plate. Detailed Implementation

[0033] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0034] like Figure 1The UAV-based highway subgrade high slope displacement monitoring device shown includes a ground reference substation for data interaction via wireless signals, an UAV-borne monitoring subsystem, slope target measuring point components, and a back-end control subsystem. The ground reference substation is erected on stable, undisturbed ground around the slope, providing an absolute coordinate reference for the entire system. The ground reference substation includes an RTK reference receiver, a data transmission radio, and a solar power and energy storage module. The RTK reference receiver continuously receives satellite positioning signals, calculates its own precise coordinates, and then sends differential correction signals to the UAV in the air via the data transmission radio. The UAV-borne monitoring subsystem is mounted beneath the UAV and is responsible for on-site data acquisition and preliminary calculation. The UAV-borne monitoring subsystem includes a three-axis stabilization gimbal, a high-definition fixed-focus industrial camera, a miniature LiDAR, an airborne RTK rover, an airborne processing unit, and a wireless data transmission module. The three-axis stabilization gimbal is rigidly connected to the bottom of the UAV fuselage to reduce flight vibrations and ensure that the acquisition equipment is always aligned with the slope. A high-definition fixed-focus industrial camera is mounted on a gimbal to capture images of slope targets, outputting high-definition images with pose tags. A miniature LiDAR is rigidly connected to the camera, covering the entire slope area, and is used to collect 3D point cloud data of the slope. An airborne RTK rover receives differential signals from a ground-based reference station and outputs high-precision position and attitude data of the UAV in real time. The airborne processing unit is an embedded industrial control module, electrically connected to the camera, LiDAR, and RTK module, which identifies targets and calculates preliminary displacements in real time. A wireless data transmission module communicates with the back-end control subsystem, transmitting early warning information and key data in real time. The back-end control subsystem includes an industrial control host, a storage module, an early warning output module, and a human-machine interface, used for flight path planning, data refinement, and tiered early warning output.

[0035] like Figure 2 As shown, the slope target measuring point assembly includes a limiting box 3 and an outer sleeve 5. The outer sleeve 5 is inserted into the soil, and the limiting box 3 is located on the slope surface. The outer sleeve 5 is made of galvanized steel, which has good corrosion resistance and structural strength, and is suitable for long-term field installation.

[0036] like Figure 8 As shown, the top of the limiting box 3 has a circular cavity 28, and the inner walls of both sides of the circular cavity 28 have interconnected circular holes 33. The two circular holes 33 are rotatably connected to the same rotating shaft I 35, as shown. Figure 9 The outer wall of the rotating shaft I35 shown is fixedly fitted with a rotating flap 2, and the outer wall of the rotating flap 2 is covered with a material such as... Figure 7 The rubber ring 30 shown has a support block I 29 fixedly installed on one inner wall of the circular cavity 28. The support block I 29 is used to support the rotating flap 2. Further, a mounting circular plate 43 is detachably connected to the bottom of the rotating flap 2. The bottom of the mounting circular plate 43 has an opening as shown in the figure. Figure 10The annular outer groove 45 shown has multiple threaded holes 44 for connecting with the rotating flap 2. The bottom of the mounting plate 43 has a mounting cavity 46, and a target plate 47 is fixedly embedded inside the mounting cavity 46. Specifically, the surface of the target plate 47 is provided with a high-contrast centering pattern, which can be accurately identified by a high-definition fixed-focus industrial camera, providing a stable point reference for slope displacement calculation.

[0037] The limiting box 3 has symmetrically arranged openings on one side, such as Figure 2 The two inclined air inlet slots 4 shown have an inner wall on one side with a groove as shown in the figure. Figure 8 The horizontal groove 32 shown is the air duct 39. A vertical groove 31, connected to the top of the horizontal groove 32, is formed and communicates with the circular hole 33. A piston plate 42 is slidably connected inside the air duct 39. Figure 9 A connecting plate 41 is fixedly connected to one side of the piston plate 42 shown. A sliding cross plate 27 is fixedly installed at one end of the connecting plate 41. The sliding cross plate 27 is slidably connected inside the transverse groove 32. A compression spring 38 is provided between one side of the sliding cross plate 27 and one side of the inner wall of the transverse groove 32. A rack 40 is fixedly installed on the top of the connecting plate 41. A rotating shaft II 36 is rotatably connected between the inner walls of the two sides of the vertical groove 31. A driving gear 37 that meshes with the rack 40 is fixedly sleeved on the outer wall of the rotating shaft II 36. A driven gear 34 that meshes with the driving gear 37 is fixedly sleeved on the outer wall of the rotating shaft I 35. Based on this, when the UAV 1 hovers above the location to carry out observation operations, the downward airflow converges into the air duct 39 through the inclined air inlet 4. The airflow pressure pushes the piston plate 42 to move laterally along the air duct 39, causing the connecting plate 41 and the rack 40 to move synchronously. The rack 40 meshes and drives the drive gear 37 to rotate, which in turn drives the rotating shaft I 35 to rotate via the driven gear 34. Finally, the rotating flap 2 is driven to flip downward, exposing the target plate 47 below for the acquisition equipment to take pictures. After the operation is completed, the UAV flies away, the compression spring 38 rebounds and pushes the sliding horizontal plate 27 to reset, causing the rotating flap 2 to rotate back to the initial position, covering the top opening of the circular cavity 28, blocking the influence of external dust and light on the target plate 47. The inner wall of the horizontal groove 32 is provided with a limit platform to limit the reset stroke of the sliding horizontal plate 27.

[0038] like Figure 4 As shown, the inner wall of the outer sleeve 5 is provided with a sliding groove 10, and a sliding block 12 is slidably connected inside the sliding groove 10. An inner cylinder 11 is fixedly installed between two sliding blocks 12. An inverted conical block 13 is fixedly installed at the bottom of the inner cylinder 11, a connecting block 14 is fixedly installed at the bottom of the inverted conical block 13, a sealing head 15 is fixedly installed at the bottom of the connecting block 14, and a fixing tip 6 is fixedly installed at the bottom of the sealing head 15. Preferably, the inverted conical block 13 is made of alloy steel, possessing high structural rigidity, capable of stably transmitting expansion force, and not prone to deformation during long-term use.

[0039] like Figure 5 As shown, the bottom of the outer sleeve 5 is integrally formed with multiple metal skeleton pieces 21, which are arranged in a ring at the bottom of the outer sleeve 5. A vertical hole 18 is provided in the middle of the bottom of the metal skeleton piece 21, and serrated ends 20 are provided on both sides of the bottom of the metal skeleton piece 21. A side arc-shaped block 17 is fixedly installed on the inner wall of the metal skeleton piece 21, and a rubber pad 16 is fixedly installed on one side of the side arc-shaped block 17. An arc-shaped surface 22 is provided at the top of the gap between the metal skeleton pieces 21, and a conical surface 19 is provided on the inner side of the metal skeleton piece 21.

[0040] like Figure 6 As shown, multiple limiting base plates 23 are fixedly installed on the top of the sealing head 15. These limiting base plates 23 fill the gaps between multiple metal skeleton pieces 21. Multiple insertion blocks 24 are fixedly installed on the top of the sealing head 15, and these insertion blocks 24 cooperate with the vertical holes 18. A support block II 25 is fixedly installed on the top of the limiting base plates 23, located below the side arc-shaped block 17. An outer limiting plate 26 is fixedly installed on the top of the support block II 25, located on one side of the side arc-shaped block 17. Specifically, during the initial insertion of the device into the soil layer, the insertion blocks 24 are embedded inside the vertical holes 18. The outer limiting plate 26 and the support block II 25 provide lateral and vertical constraints to the side arc-shaped block 17, keeping the multiple metal skeleton pieces 21 in a closed state, preventing premature expansion during insertion, and ensuring the device can be smoothly driven into the predetermined depth.

[0041] During installation, the outer sleeve 5 and inner sleeve 11 are driven vertically into the predetermined position on the slope as a whole. The fixed tip 6 first penetrates the soil layer and guides the whole device deeper until the fixed tip 6 enters the deep stable soil layer. After being driven into place, a downward force is applied to the inner sleeve 11. The inner sleeve 11 slides downward along the sliding groove 10 through the sliding block 12, driving the inverted cone block 13 downward synchronously. The inverted cone block 13 drives the sealing head 15 downward through the connecting block 14, causing the insertion block 24 to move out of the vertical hole 18. The outer limiting plate 26 and the support block II 25 simultaneously release the constraint on the side arc block 17. As the inverted cone block 13 continues to descend, its cone surface abuts against the cone surface 19 on the inner side of the metal skeleton piece 21, pushing multiple metal skeleton pieces 21 to open outward. The serrated end 20 cuts into the surrounding soil to form an interlock, completing the initial anchoring.

[0042] like Figure 3As shown, the bottom of the limiting box 3 has an installation groove 7, and an internal threaded block 8 is fixedly installed on the inner wall of the installation groove 7. An arc surface 9 is provided on one side of the bottom of the installation groove 7, and the outer sleeve 5 is threadedly connected to the installation groove 7. After the limiting box 3 is screwed onto the top of the outer sleeve 5, the bottom of the internal threaded block 8 abuts against the top of the inner cylinder 11, restricting the freedom of the inner cylinder 11 to move upward. When the surface soil of the slope tends to slide, the outer sleeve 5 will move along with the surface soil. The inner cylinder 11 and the inverted cone block 13 remain relatively stationary because they are anchored in the deep stable soil layer. The relative displacement between the outer sleeve 5 and the inner cylinder 11 causes the inverted cone block 13 to move downward relative to the cone surface 19 of the metal skeleton piece 21. The cone surface of the inverted cone block continuously contacts the cone surface 19 on the inner side of the metal skeleton piece, increasing the outward expansion of the metal skeleton piece 21, expanding the anchoring contact area, and the stronger the sliding tendency, the higher the anchoring resistance, forming a self-reinforcing anchoring effect. During long-term deployment in the field, this device requires regular cleaning of accumulated dust and debris at the inclined air inlet slot, and inspection of the target plate's surface condition and the stability of the anchoring structure to ensure the accuracy of monitoring data and the reliability of device operation.

[0043] During the operation of the entire device, the ground reference substation provides a stable coordinate reference, the UAV1 carries the airborne monitoring subsystem to complete the slope data collection according to the preset route, the slope target measuring point component provides a stable and reliable observation point, and the collected data is wirelessly transmitted to the background management subsystem to complete fine processing and displacement calculation, which can realize long-term continuous displacement monitoring of high slopes of highway subgrade.

[0044] When using this UAV-based highway subgrade high slope displacement monitoring device, it is necessary to first pre-embed the outer sleeve 5, and insert the outer sleeve 5 and the inner sleeve 11 as a whole into the predetermined position. At this time, the fixed tip 6 enters the stable soil layer, and the side arc blocks 17 between multiple metal skeleton pieces 21 abut against each other. Furthermore, since the outer limiting plate 26 blocks the two adjacent side arc blocks 17, and the support block II 25 lifts the side arc blocks 17, it can ensure that the metal skeleton pieces 21 will not disperse in advance during the initial insertion, thus ensuring the stability of the insertion.

[0045] After insertion, the inner cylinder 11 is pushed further into the soil layer by the external device. The inner cylinder 11 drives the inverted cone block 13 to move down, the inverted cone block 13 drives the connecting block 14 to move down, the connecting block 14 drives the sealing head 15 to move down, and the sealing head 15 drives the fixed tip 6 to insert into a deeper stable soil layer. The insertion block 24 moves out of the vertical hole 18, and the outer limit plate 26 and the support block II 25 no longer abut against the side arc block 17. At this time, the cone surface of the inverted cone block 13 abuts against the cone surface 19 on the inner side of the metal skeleton piece 21, pushing multiple metal skeleton pieces 21 to open outward and pierce into the surrounding soil like claws.

[0046] At this point, the upper limiting box 3 is threaded onto the top of the outer sleeve 5, and the internal threaded block 8 abuts against the top of the inner cylinder 11, completely sealing the space for the inner cylinder 11 to move downwards, ensuring that the inner cylinder 11 will not move upwards. Once the soft substrate of the slope experiences surface slippage, it will generate an outward pulling force on the outer sleeve 5. Since the inverted cone block 13 is deeply embedded in the relatively stable area of ​​the bottom layer, the surface pulling force will be physically converted into the relative displacement between the outer sleeve 5 and the inner cylinder 11, forcing the inverted cone block 13 to further expand the metal skeleton plate 21 outwards significantly. That is, the stronger the slope slippage tendency, the greater the resistance surface that the anchor bolt expands in the soft substrate, physically achieving a self-locking effect of "the more it is pulled, the tighter it becomes";

[0047] When the drone 1 hovers near the limit box 3, the powerful airflow is collected through the inclined air inlet 4 and quickly enters the interior of the air duct 39. Due to the sudden drop in size, the pressure increases, and the piston plate 42 is pushed. The piston plate 42 drives the connecting plate 41 to move laterally. The connecting plate 41 drives the sliding cross plate 27 to move laterally. The sliding cross plate 27 compresses the spring 38. The connecting plate 41 drives the rack 40 to move laterally. The rack 40 drives the driving gear 37 to rotate. The driving gear 37 drives the driven gear 34 to rotate. At this time, the driven gear 34 drives the rotating shaft I 35 to rotate. The rotating shaft I 35 drives the rotating flap 2 to rotate. The rotating flap 2 drives the mounting circular plate 43 below to rotate. The mounting circular plate 43 drives the target plate 47 inside to rotate. Thus, when not in use, the target plate 47 can be protected, extending its service life.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A device for monitoring the displacement of high slopes of highway subgrade based on unmanned aerial vehicles (UAVs), characterized in that, The system includes a drone (1) equipped with an airborne monitoring subsystem and a slope target measuring point assembly. The slope target measuring point assembly includes a limiting box (3) located on the slope surface and an outer sleeve (5) inserted into the soil. The limiting box (3) has a circular cavity (28) at the top, and a rotating flap (2) driven by the airflow of the drone (1) is rotatably installed inside the circular cavity (28). The bottom of the rotating flap (2) is detachably connected to a mounting plate (43), and the bottom of the mounting plate (43) has an mounting cavity (46) in which a target plate (47) is fixedly embedded. The outer sleeve (5) slides inside the groove. The inner cylinder (11) is connected to the moving part. The bottom of the inner cylinder (11) is fixedly installed with an inverted conical block (13), a connecting block (14), a sealing head (15) and a fixed tip (6). The bottom of the outer sleeve (5) is integrally formed with multiple metal skeleton pieces (21). The top of the sealing head (15) is fixedly installed with multiple limiting base plates (23) that fill the gaps between the metal skeleton pieces (21). The inner wall of the metal skeleton pieces (21) is fixedly installed with a side arc block (17). The top of the limiting base plate (23) is fixedly installed with a support block II (25) for supporting the side arc block (17) in the initial position.

2. The UAV-based highway subgrade high slope displacement monitoring device as described in claim 1, characterized in that, The inner walls of both sides of the circular cavity (28) are provided with interconnected circular holes (33), and the two circular holes (33) are rotatably connected to the same rotating shaft I (35) of the rotating flap (2).

3. The UAV-based highway subgrade high slope displacement monitoring device as described in claim 2, characterized in that, The limiting box (3) has two symmetrically arranged inclined air inlet slots (4) on one side. The inner wall of one side of the inclined air inlet slot (4) has a horizontal slot (32) that serves as an air duct (39). The top of the horizontal slot (32) has a vertical slot (31) that is connected to it. The vertical slot (31) is connected to the round hole (33).

4. The UAV-based highway subgrade high slope displacement monitoring device as described in claim 3, characterized in that, The air duct (39) is slidably connected to a piston plate (42), and a connecting plate (41) is fixedly connected to one side of the piston plate (42). A sliding horizontal plate (27) is fixedly installed at one end of the connecting plate (41). The sliding horizontal plate (27) is slidably connected to the inside of the horizontal groove (32). The same compression spring (38) is provided between the sliding horizontal plate (27) and the inner wall of the horizontal groove (32) away from the inclined air inlet groove (4). A rack (40) is fixedly installed on the top of the connecting plate (41). The same rotating shaft II (36) is rotatably connected between the inner walls of the two sides of the vertical groove (31). The outer wall of the rotating shaft II (36) is fixedly sleeved with a driving gear (37) that meshes with the rack (40). The outer wall of the rotating shaft I (35) is fixedly sleeved with a driven gear (34) that meshes with the driving gear (37).

5. The UAV-based highway subgrade high slope displacement monitoring device as described in claim 1, characterized in that, A support block I (29) is fixedly installed on one side of the inner wall of the circular cavity (28). The support block I (29) is used to support the rotating flap (2). The outer wall of the rotating flap (2) is covered with a rubber ring (30).

6. The UAV-based highway subgrade high slope displacement monitoring device as described in claim 1, characterized in that, The inner wall of the outer sleeve (5) is provided with a sliding groove (10), and a sliding block (12) is slidably connected inside the sliding groove (10). The two sliding blocks (12) are fixedly installed on the outer wall of the inner sleeve (11).

7. The UAV-based highway subgrade high slope displacement monitoring device as described in claim 1, characterized in that, The multiple metal skeleton pieces (21) are arranged in a ring at the bottom of the outer sleeve (5). A vertical hole (18) is provided in the middle of the bottom of the metal skeleton piece (21). A serrated end (20) is provided on both sides of the bottom of the metal skeleton piece (21). Rubber pads (16) are fixedly installed on both sides of the side arc block (17). The top of the gap between the metal skeleton pieces (21) is set as an arc surface (22). A conical surface (19) is provided on the inner side of the metal skeleton piece (21).

8. The UAV-based highway subgrade high slope displacement monitoring device as described in claim 7, characterized in that, The top of the sealing head (15) is fixedly installed with multiple plug-in blocks (24), which are used in conjunction with the vertical hole (18). The support block II (25) on the top of the limiting base plate (23) is located below the side arc block (17), and the top of the support block II (25) is fixedly installed with an outer limiting plate (26) located on one side of the side arc block (17).

9. The UAV-based highway subgrade high slope displacement monitoring device as described in claim 6, characterized in that, The bottom of the limiting box (3) is provided with an installation groove (7), and an internal thread block (8) is fixedly installed on the inner wall of the installation groove (7). An arc surface (9) is provided on one side of the bottom of the installation groove (7), and the outer sleeve (5) is threadedly connected to the internal thread block (8).

10. A monitoring method for a high slope displacement monitoring device for highway subgrade based on any one of claims 1-9, characterized in that, Includes the following steps: S1. Baseline layout and point pre-embedding: Set up ground reference substations in the stable area around the slope, drive the outer sleeve (5) and inner sleeve (11) into the predetermined position on the slope, push the inner sleeve (11) down to expand the metal skeleton piece (21) to complete the initial anchoring, screw the limiting box (3) onto the top of the outer sleeve (5) to complete the target measurement point layout, collect the initial coordinates of each measurement point and construct the slope reference model and store it in the background control subsystem; S2, Inspection route planning, the background control subsystem plans the autonomous inspection route of the UAV (1) according to the slope range and the location of the measuring point, and sets the hovering observation position and flight parameters of each measuring point; S3. Airborne data acquisition: The UAV (1) flies autonomously along the preset route. The airborne RTK rover receives the differential signal from the ground reference substation to obtain high-precision pose. The high-definition fixed-focus industrial camera and the miniature laser radar simultaneously collect slope images and point cloud data. When the UAV (1) approaches the measurement point, the downward airflow drives the rotating flap (2) to open, revealing the target plate (47) to complete the fixed-point shooting. S4. Initial displacement judgment at the airborne end: the airborne processing unit identifies the target plate (47) in the acquired image and calculates the current coordinates of the measurement point. It compares the current coordinates with the initial reference coordinates to obtain the displacement. If the displacement exceeds the preset threshold, it transmits the warning information back to the background control subsystem through the wireless data transmission module. S5. Background fine processing and analysis: After the UAV (1) returns, it will upload the complete data to the background control subsystem. The background control subsystem will perform splicing and registration processing on the data, generate the current slope three-dimensional model, and perform a full-domain deformation comparison analysis with the benchmark model to obtain the full slope displacement distribution results. S6. Data archiving and early warning output: The background management subsystem stores the current monitoring data and generates monitoring reports. It classifies early warning levels according to displacement and displacement rate, and pushes corresponding early warning information through the early warning output module.

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