An inspection unmanned aerial vehicle and an application method thereof in a bridge-water composite scene

Abstract

This invention relates to the field of unmanned aerial vehicle (UAV) technology, providing an inspection UAV and its application method in bridge-water composite scenarios, solving the problems of existing UAVs having defects that prevent real-time on-site marking of anomalies and poor reliability of water surface marking. The invention includes: a UAV body; a three-axis camera fixed to a first side of the bottom of the UAV body; at least one delivery chamber fixed to a second side of the bottom of the UAV body opposite to the first side, the delivery chamber having a clamping opening at its bottom; at least one delivery object clamped between the opening and closing hooks, the delivery object being divided into bridge surface delivery objects and water surface delivery objects; an opening and closing component located above the delivery chamber, used to drive each opening and closing hook to rotate relative to the corresponding mounting rod; this invention integrates a three-axis camera and a dual-type delivery system, allowing the UAV to directly deliver corresponding markers to anomaly locations while simultaneously performing image inspections of road surfaces, bridge surfaces, and water surfaces.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, specifically to an inspection UAV and its application method in a bridge-water complex scenario. Background Technology

[0002] In recent years, drone technology has been widely used in the field of municipal infrastructure inspection. Compared with traditional manual inspection methods, it has significant advantages such as wide coverage, high operating efficiency, and no risk of high-altitude operation. It has become one of the core equipment for the daily operation and maintenance of municipal facilities such as bridges, roads, and waterworks.

[0003] In existing technologies, inspection drones primarily function with image acquisition, using high-definition cameras, infrared cameras, and other equipment to identify and record surface defects in facilities. To enhance the versatility of drones, some technologies have proposed modular design schemes. For example, Chinese Patent Publication No. CN116750222A discloses a modular inspection drone that uses a quick-connect structure with hook-shaped and engaging parts between the drone assembly and functional components. This allows for the rapid assembly and disassembly of functional components such as cutting and observation parts, effectively solving the problems of cumbersome component replacement and low operational efficiency in power tree obstruction clearing scenarios.

[0004] However, the aforementioned existing technologies and current mainstream inspection drones still have the following unresolved technical shortcomings, making them particularly difficult to adapt to the refined inspection needs of complex bridge and waterway scenarios:

[0005] Existing inspection drones can only capture images of abnormal locations and transmit them back to the ground station. They cannot mark the abnormalities on-site immediately upon discovery. For abnormalities such as bridge surface cracks and potholes, missing manhole covers, cracks and potholes on the road surface, illegal sewage outlets, floating garbage accumulation areas, and black and smelly water sections, manual secondary investigation and location based on aerial images is required. This is not only time-consuming and labor-intensive, but also extremely difficult to locate manually on elevated road sections with heavy traffic. This results in long response times for maintenance and law enforcement. For emergency situations such as road collapse hazards and missing manhole covers, warning signs cannot be set up quickly, which can easily lead to secondary accidents.

[0006] Existing water surface warning markers mainly rely on manually deployed buoys or electronically triggered inflatable markers, which have significant shortcomings: First, manual deployment cannot reach dangerous or remote waters and poses safety risks in emergency scenarios; second, electronically triggered markers rely on batteries and sensors, have poor waterproof performance, are prone to failure in low temperature and high humidity environments, and have short storage life; third, ordinary buoys have no fixing devices, are easily washed away by water currents after deployment, and the marker position drifts significantly, making it impossible to pinpoint the source of the anomaly. Summary of the Invention

[0007] Therefore, in order to address the above problems, the present invention provides an inspection unmanned aerial vehicle and its application method in a bridge-water composite scenario, which solves the problems of existing drones being unable to mark anomalies on-site in real time due to defects and the poor reliability of water surface marking.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0009] An inspection unmanned aerial vehicle includes:

[0010] The drone itself;

[0011] A three-axis camera is fixed to the first side of the bottom of the UAV body;

[0012] At least one delivery compartment is fixed to the bottom of the UAV body on the second side opposite to the first side. The bottom of the delivery compartment is provided with a clamping opening. The delivery compartment includes two symmetrically arranged mounting rods and opening and closing hooks respectively sleeved on each of the mounting rods. The tops of each opening and closing hook are connected by interlocking toothed transmission. The bottoms of each opening and closing hook are bent towards each other and spaced apart to form the clamping opening.

[0013] At least one launcher is held between each of the opening and closing hooks. The launcher is divided into two categories: bridge deck launchers and water surface launchers. The bridge deck launcher includes a protective shell and a positioning module disposed inside the protective shell. The water surface launcher includes a ring-shaped, two-lobed sinking block, a connecting line connected to the sinking block at one end, and a float connected to the other end of the connecting line. The float includes a sealed marker bag, reactive powder filled in the marker bag, and a reactive liquid capsule disposed in the marker bag. The reactive powder generates gas upon contact with the reactive liquid, causing the marker bag to expand. The float is held between the two lobes of the sinking block, and the reactive liquid capsule is located in the inner ring area of ​​the sinking block.

[0014] An opening and closing component is located above the delivery compartment and is used to drive each of the opening and closing hooks to rotate relative to the corresponding mounting rod.

[0015] Furthermore, the reaction system between the reaction powder and the reaction liquid inside the capsule can be any one of the following:

[0016] The reaction solution is pure water, and the reaction powder is a dry powder that can generate gas when it comes into contact with water.

[0017] The reaction solution is an acidic aqueous solution, and the reaction powder is one or more of carbonate powder and bicarbonate powder.

[0018] Furthermore, an annular boss for the connecting wire to be wound is integrally formed on the outer wall of the sinking block.

[0019] Furthermore, the opening and closing component includes a driving member and an opening and closing gear disposed at the driving end of the driving member, the opening and closing gear engaging with the teeth at the tip of one of the opening and closing hooks.

[0020] Furthermore, the coverage area of ​​the expanded marker bag is positively correlated with the weight of the sinking block.

[0021] Furthermore, when the number of the items to be placed is greater than or equal to two, the adjacent items to be placed are staggered.

[0022] Furthermore, the cross-section of the object placed on the bridge deck is circular and the overall structure is symmetrical. A through cavity is coaxially provided inside the protective shell. The top and bottom of the through cavity are detachably connected to cover plates. The positioning module is installed inside the through cavity.

[0023] Furthermore, the outer surface of the object placed on the bridge deck is provided with a friction layer, and the upper and lower surfaces of the friction layer are provided with the same isotropic texture, which is one of the following: honeycomb groove texture, dense hemispherical protrusion texture, and diamond grid texture.

[0024] Furthermore, the upper and lower edges of the protective shell are rounded, with a radius of ≥0.8×thickness of the protective shell, and the ratio of the diameter to the thickness of the protective shell is ≥3, so that it is not easy to overturn under rolling conditions.

[0025] A method for applying an inspection unmanned aerial vehicle (UAV) in a bridge-water complex scenario, using the aforementioned inspection UAV, includes the following steps:

[0026] S1. Inspection Flight: Control the UAV body to fly along a preset route, and collect image data of the bridge surface or water surface in real time through the three-axis camera and transmit it back to the ground station;

[0027] S2. Anomaly Identification: The ground station analyzes the transmitted image data to identify the bridge surface markers or water surface markers.

[0028] S3. Object matching: If a bridge surface marker is detected, the object to be placed on the bridge surface is matched and selected; if a water surface marker is detected, the object to be placed on the water surface is matched and selected.

[0029] S4. Deployment: Control the UAV to fly to and hover above the corresponding marked point; when matching a bridge surface deployment object, activate the opening and closing component, which drives the two opening and closing hooks to rotate relative to each other to open the clamping opening and release the bridge surface deployment object; when matching a water surface deployment object, activate the opening and closing component, which drives the two opening and closing hooks to rotate relative to each other to close the clamping opening, rupture the reaction liquid capsule, and then open the clamping opening to release the water surface deployment object;

[0030] S5, Inspection and Return: After marking and locating all marked points, control the UAV to return to the take-off and landing point.

[0031] The above technical solution has the following advantages, unlike existing technologies:

[0032] This invention integrates a three-axis camera and a dual-type delivery system. While performing image inspections of roads, bridges, and water surfaces, the drone can directly deliver corresponding markers to anomaly locations, solving the problems of traditional inspections that only allow for photo recording, subsequent manual investigation and location difficulties, and untimely marking. The water surface delivery uses a ring-shaped, two-lobed sinking block that holds the float and a reaction liquid capsule inside the marker bag. Before delivery, it is a compact, integrated unit for easy clamping. During delivery, the opening and closing hook squeezes inward, breaking the reaction liquid capsule, allowing the reaction powder and reaction liquid to come into contact and generate gas. Then, the opening and closing hook releases the water surface delivery outward. After falling into the water, the sinking block separates under gravity and sinks, while the marker bag expands to form a conspicuous water surface warning sign. Furthermore, the sinking block pulls the float via a connecting line, effectively preventing the float from being washed away by the water flow, resulting in minimal marking position error. The bridge surface delivery has an independent positioning module that can send location information to the ground station in real time after landing on the bridge or road surface, solving the problem of difficulty in quickly locating anomalies manually. The protective shell effectively cushions the impact upon landing, ensuring the positioning module continues to function normally after high-altitude delivery. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the delivery bin holding the object to be delivered on the bridge deck, according to an embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram of the structure of the delivery bin holding the surface-delivered material according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic cross-sectional view of the object placed on the bridge deck according to an embodiment of the present invention;

[0037] Figure 5 This is a schematic cross-sectional view of the material placed on the water surface according to an embodiment of the present invention.

[0038] Explanation of icon numbers:

[0039] Drone body 1;

[0040] Three-axis camera 2;

[0041] Dispensing bin 3; Installation rod 31; Opening and closing hook 32;

[0042] Item 4; Item 41 on bridge deck; Protective shell 411; Through cavity 412; Sealing cover 413; Positioning module 414; Anti-slip friction layer 415; Item 42 on water surface; Sinking block 421; Connecting line 422; Float 423; Annular boss 424; Marking bag 425; Reaction powder 426; Reaction liquid capsule 427;

[0043] 5. Opening and closing component; 51. Driving component; 52. Opening and closing gear. Detailed Implementation

[0044] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0045] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0046] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0047] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0048] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0049] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0050] As understood in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0051] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0052] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0053] Example 1: Please refer to Figures 1 to 5 This embodiment provides an inspection drone suitable for bridge-water composite scenarios, aiming to solve the problems of existing drones being unable to mark anomalies on-site in real time due to defects, and the poor reliability of water surface marking.

[0054] The inspection drone described in this embodiment includes a drone body 1, a three-axis camera 2, three delivery bays 3, three delivery items 4, and three opening and closing components 5. The drone body 1 and the three-axis camera 2 are both existing components. In this embodiment, the drone body 1 is a hexacopter drone, and the three-axis camera 2 is a three-axis zoom gimbal camera. Both can be purchased from the market and will not be described in detail here.

[0055] Each delivery bin 3 corresponds to one delivery item 4 and an independent opening and closing component 5. Each opening and closing component 5 independently controls the opening and closing action of its corresponding delivery bin 3 without interfering with each other.

[0056] The three-axis camera 2 is fixed to the first side of the bottom of the UAV body 1, and the three delivery compartments 3 are fixed to the second side of the bottom of the UAV body 1 opposite to the first side in sequence and staggered. The direction of the line connecting the first side and the second side of the UAV body is defined as longitudinal, and the direction perpendicular to the longitudinal direction is defined as transverse. All delivery compartments 3 are arranged in a staggered manner along the transverse direction to ensure the balance of the center of gravity of the whole aircraft during flight.

[0057] The three delivery items 4 are each independently clamped in one of the three delivery chambers 3; in other preferred embodiments, the number of delivery chambers 3, delivery items 4 and opening / closing components 5 can be simultaneously adjusted to 1, 2, 4 or 5.

[0058] The three opening and closing components 5 are all fixed to the bottom of the UAV body 1 and are located directly above each delivery compartment 3, respectively, for independently driving the opening and closing action of the corresponding delivery compartment 3.

[0059] Each of the dispensing compartments 3 has an independent clamping opening at its bottom; each dispensing compartment 3 includes two symmetrical and vertically arranged mounting rods 31, and opening and closing hooks 32 respectively rotatably sleeved on the two mounting rods 31. The tops of the two opening and closing hooks 32 are connected by interlocking toothed transmission, and the bottoms of the two opening and closing hooks 32 are bent towards each other and spaced apart, together forming the clamping opening of the dispensing compartment 3. The opening and closing hooks 32 are L-shaped rods, and their short shaft ends are provided with silicone protective sleeves.

[0060] Each of the opening and closing components 5 includes a driving component 51 and an opening and closing gear 52 coaxially fixed to the output shaft of the driving component 51. In this embodiment, all driving components 51 are DC geared motors. In other preferred embodiments, the driving component 51 can also be a stepper motor, a servo motor, or an electric telescopic rod. When an electric telescopic rod is used, the driving end of the electric telescopic rod is connected to a toothed rod (not shown in the figure) that meshes with the opening and closing gear 52. This is an existing technology and will not be described in detail here. The opening and closing gear 52 meshes with the teeth at the top of one of the opening and closing hooks 32 in the corresponding delivery compartment 3. The driving component 51 drives the opening and closing hook 32 to rotate through the opening and closing gear 52, and then drives the other opening and closing hook 32 to rotate synchronously in the opposite direction through the meshing teeth at the top, thereby realizing the independent opening and closing of the corresponding clamping opening.

[0061] The delivery items 4 are divided into bridge delivery items 41 and water delivery items 42. In this embodiment, the delivery compartments 3 on the left and right sides carry bridge delivery items 41, and the delivery compartment 3 in the middle carries water delivery items 42. In other preferred embodiments, when carrying more delivery items, the delivery compartments 3 can be arranged in two rows along the longitudinal direction. The water delivery items 42 are preferentially placed in the delivery compartment 3 at the central axis of the UAV body 1 to concentrate the center of gravity.

[0062] The surface launcher 42 includes a ring-shaped two-lobed sinker 421, a connecting line 422 fixedly connected to the sinker 421 at one end, and a float 423 connected to the other end of the connecting line 422.

[0063] The outer wall of the sinking block 421 is integrally formed with an annular boss 424 for winding the connecting line. The annular boss 424 provides a dedicated winding space for the connecting line, making the overall structure of the water surface deployment more regular and compact, avoiding the connection line from getting stuck due to loose winding before deployment, and protecting the connection line from wear and breakage during storage and deployment. In this embodiment, the length of the connecting line 422 is five meters, which is wound around the annular boss 424. In other preferred embodiments, the length of the connecting line can be adjusted according to the water depth of the operating area.

[0064] The float 423 includes a marker bag 425, a reaction powder 426 filled inside the marker bag, and a reaction liquid capsule 427 sealed inside the marker bag. The float 423 is held between two sinking blocks, and the reaction liquid capsule 427 is located in the inner ring area of ​​the sinking block 421. The reaction liquid capsule 427 is wrapped with a starch-based biodegradable film.

[0065] In this embodiment, the sinking block 421 adopts a ring-shaped two-lobed structure formed by polishing natural river pebbles; the marking bag 425 is made of PLA material that can be inflated and degraded in fresh water; the connecting line 422 is made of Tencel wire, which can be naturally degraded in fresh water environment, with moderate strength and low cost.

[0066] In other preferred embodiments, the sinking block 421 may also be made of natural stone such as granite, basalt, marble, quartz, sandstone or limestone; the label bag 425 may also be made of PBAT material or latex material; the connecting line 422 may also be made of any one of cotton thread, hemp thread, bamboo fiber thread, PLA biodegradable thread or pure wood pulp paper rope.

[0067] In this embodiment, the reaction system uses pure water as the reaction solution and dry powder of sodium carbonate and sodium bicarbonate mixed in a mass ratio of 1:1. In other preferred embodiments, the following reaction system can also be used: citric acid aqueous solution as the reaction solution and sodium bicarbonate powder as the reaction powder.

[0068] The coverage area of ​​the expanded marker bag 425 is positively correlated with the weight of the sinking block 421. By quantitatively matching the expanded area of ​​the marker bag 425 with the weight of the sinking block 421, the delivery material 4 can be customized according to the water flow speed of different water areas.

[0069] The cross-section of the bridge deck object 41 is circular and the overall structure is symmetrical. The protective shell 411 is made of cast iron in one piece. The protective shell 411 has a through cavity 412 that runs vertically through the center. The upper and lower ends of the through cavity 412 are provided with chamfers to avoid stress concentration. The top and bottom of the through cavity 412 are respectively connected to sealing cover plates 413 by threads. The positioning module 414 is fixed in the through cavity 412 by potting compound. The positioning module 414 is an existing component, such as a Beidou positioning module or a GPS positioning module, which can be purchased from the market and will not be described in detail here.

[0070] The outer surface of the protective shell 411 of the bridge deck object 41 is provided with an anti-slip friction layer 415, which is made of polytetrafluoroethylene (PTFE) thin coating. In this embodiment, the upper and lower surfaces of the anti-slip friction layer 415 are provided with the same dense hemispherical raised texture. In other preferred embodiments, a honeycomb groove texture or a diamond grid texture can also be used.

[0071] In this embodiment, the upper and lower edges of the protective shell 411 are provided with transition rounded corners, the radius of which is 1 × the thickness of the protective shell, and the ratio of the diameter to the thickness of the protective shell 411 is 4. In other preferred embodiments, as long as the radius of the rounded corner is ≥0.8 × the thickness of the protective shell and the ratio of the diameter to the thickness is ≥3, the effect of resisting crushing and not easily turning over can be achieved.

[0072] Example 2: This example provides a method for applying an inspection drone in a bridge-water complex scenario, using the inspection drone described in Example 1, and includes the following steps:

[0073] S1. Inspection Flight: Control the UAV body 1 to fly along the preset bridge, road or water surface inspection route, collect high-definition image data in real time through the three-axis camera 2, and transmit it back to the ground control station through the wireless communication module.

[0074] S2. Anomaly Identification: The ground control station uses a built-in image recognition algorithm to analyze the transmitted image data in real time, automatically or manually identifying bridge surface markers such as cracks, potholes, and missing manhole covers, as well as water surface markers such as illegal sewage outlets, floating garbage accumulation areas, and black and odorous water sections.

[0075] S3. Dispatch matching: If a bridge or road marker is detected, the corresponding dispatch bin carrying bridge surface dispatch 41 is selected; if a water surface marker is detected, the corresponding dispatch bin carrying water surface dispatch 42 is selected.

[0076] S4. Deployment: Control the drone to fly to and hover above the corresponding marked point.

[0077] When the bridge surface object 41 is matched, the drive component 51 of the corresponding delivery bin 3 is activated to rotate forward, which drives the two opening and closing hooks 32 of the delivery bin 3 to rotate relative to each other to open the clamping opening and directly release the bridge surface object 41.

[0078] When matching the surface-deployed material 42, the control drone body 1 flies to a position ten meters upstream of the corresponding marked point in the direction of water flow and hovers. First, the drive component 51 of the corresponding deployment chamber 3 is activated to reverse, driving the two opening and closing hooks 32 of the deployment chamber 3 to rotate relative to each other and close the clamping opening. The squeezing force of the opening and closing hooks 32 is used to break the reaction liquid capsule 427 located in the inner ring of the sinking block 421, so that the reaction liquid comes into contact with the reaction powder and begins to react. Then, the drive component 51 is activated to rotate forward, opening the clamping opening and releasing the surface-deployed material 42.

[0079] S5, Inspection and Return: After all the marked points have been deployed, the UAV body 1 is controlled to return to the preset take-off and landing point; After the bridge surface deployment object 41 lands on the bridge surface, its internal Beidou positioning module sends the location information to the ground station in real time; After the water surface deployment object 42 lands in the water, the two sinking blocks 421 separate and sink under the action of gravity, the float 423 floats to the surface, and the marker bag 425 expands rapidly under the action of gas to form a conspicuous warning sign.

[0080] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. An inspection unmanned aerial vehicle, characterized in that, include: The drone itself; A three-axis camera is fixed to the first side of the bottom of the UAV body; At least one delivery compartment is fixed to the bottom of the UAV body on the second side opposite to the first side. The bottom of the delivery compartment is provided with a clamping opening. The delivery compartment includes two symmetrically arranged mounting rods and opening and closing hooks respectively sleeved on each of the mounting rods. The tops of each opening and closing hook are connected by interlocking toothed transmission. The bottoms of each opening and closing hook are bent towards each other and spaced apart to form the clamping opening. At least one launcher is held between each of the opening and closing hooks. The launcher is divided into two categories: bridge deck launchers and water surface launchers. The bridge deck launcher includes a protective shell and a positioning module disposed inside the protective shell. The water surface launcher includes a ring-shaped, two-lobed sinking block, a connecting line connected to the sinking block at one end, and a float connected to the other end of the connecting line. The float includes a sealed marker bag, reactive powder filled in the marker bag, and a reactive liquid capsule disposed in the marker bag. The reactive powder generates gas upon contact with the reactive liquid, causing the marker bag to expand. The float is held between the two lobes of the sinking block, and the reactive liquid capsule is located in the inner ring area of ​​the sinking block. An opening and closing component is located above the delivery bin and is used to drive each of the opening and closing hooks to rotate relative to the corresponding mounting rod. An annular protrusion for the connecting wire to be wound is integrally formed on the outer wall of the sinking block. The opening and closing component includes a driving member and an opening and closing gear disposed at the driving end of the driving member, wherein the opening and closing gear meshes with the teeth at the tip of one of the opening and closing hooks. The coverage area of ​​the inflated marker bag is positively correlated with the weight of the sinking block.

2. The inspection unmanned aerial vehicle according to claim 1, characterized in that: The reaction system between the reaction powder and the reaction liquid inside the capsule can be any one of the following: The reaction solution is pure water, and the reaction powder is a dry powder that can generate gas when it comes into contact with water. The reaction solution is an acidic aqueous solution, and the reaction powder is one or more of carbonate powder and bicarbonate powder.

3. The inspection unmanned aerial vehicle according to claim 1, characterized in that: When the number of the items to be placed is greater than or equal to two, the adjacent items to be placed are staggered.

4. The inspection unmanned aerial vehicle according to claim 1, characterized in that: The cross-section of the object to be placed on the bridge deck is circular and the overall structure is symmetrical. A through cavity is coaxially provided inside the protective shell. The top and bottom of the through cavity are detachably connected to cover plates. The positioning module is installed inside the through cavity.

5. The inspection unmanned aerial vehicle according to claim 4, characterized in that: The outer surface of the object placed on the bridge deck is provided with a friction layer, and the upper and lower surfaces of the friction layer are provided with the same isotropic texture. The isotropic texture is one of the following: honeycomb groove texture, dense hemispherical protrusion texture, and rhomboid grid texture.

6. The inspection unmanned aerial vehicle according to claim 4, characterized in that: The upper and lower edges of the protective shell are rounded with a radius of ≥0.8×thickness of the protective shell, and the ratio of the diameter to the thickness of the protective shell is ≥3, so that it is not easy to overturn under rolling conditions.

7. A method for applying an inspection unmanned aerial vehicle in a bridge-water complex scenario, characterized in that: The inspection unmanned aerial vehicle according to any one of claims 1 to 6 includes the following steps: S1. Inspection Flight: Control the UAV body to fly along a preset route, and collect image data of the bridge surface or water surface in real time through the three-axis camera and transmit it back to the ground station; S2. Anomaly Identification: The ground station analyzes the transmitted image data to identify the bridge surface markers or water surface markers. S3. Object matching: If a bridge surface marker is detected, the object to be placed on the bridge surface is matched and selected; if a water surface marker is detected, the object to be placed on the water surface is matched and selected. S4. Deployment: Control the UAV to fly to and hover above the corresponding marked point; when matching a bridge surface deployment object, activate the opening and closing component, which drives the two opening and closing hooks to rotate relative to each other to open the clamping opening and release the bridge surface deployment object; when matching a water surface deployment object, activate the opening and closing component, which drives the two opening and closing hooks to rotate relative to each other to close the clamping opening, rupture the reaction liquid capsule, and then open the clamping opening to release the water surface deployment object; S5, Inspection and Return: After marking and locating all marked points, control the UAV to return to the take-off and landing point.

Images