Natural cave detection amphibious unmanned aerial vehicle

Abstract

The invention relates to a natural cave detection amphibious unmanned aerial vehicle, and belongs to the technical field of cave detection, the natural cave detection amphibious unmanned aerial vehicle comprises a shell and a duct vertically formed in the center of the shell, a single-shaft rotor wing mechanism comprises a support, two rotating power elements and rotor wings, the two rotating power elements and the rotor wings are arranged on the support, and the support is arranged in the duct and connected with the shell; the two rotating power elements are arranged on the upper side and the lower side of the support, the two rotor wings sleeve output shafts of the rotating power elements in a one-to-one correspondence mode, the multiple anti-collision grid bars are arranged on the upper side and the lower side of the shell at equal intervals, the anti-collision grid bars are in an arc shape, and the two ends of each anti-collision grid bar are connected with the shell. The two rotors are driven by the single shaft to rotate to provide power for the unmanned aerial vehicle, so that the unmanned aerial vehicle is driven to move in the air or underwater, the unmanned aerial vehicle has a small aspect ratio, the rotors are protected at the two ends of the duct through the anti-collision grids, damage caused by collision between the rotors and rock walls is avoided, and the unmanned aerial vehicle is safe and reliable. And the natural cave detection stability of the amphibious unmanned aerial vehicle is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of cave exploration, and particularly relates to an amphibious unmanned aerial vehicle for natural cave exploration. Background Art

[0002] Caves include natural caves and artificial caves. Among them, natural caves refer to continuous or discontinuous underground spaces formed by water erosion, physical weathering, tectonic movement, structural collapse, etc., such as karst caves, underground rivers, internal channels of glaciers, natural mountain caves, etc.; artificial caves refer to regular or irregular underground spaces formed by human activities, such as drill wells, mine roadways, underground pipelines, tomb tunnels, etc. Due to reasons such as scientific research, disaster prevention and control, engineering construction, exploration and entertainment, there are many demands for the detection of cave structures and internal environments. Since caves are deep underground, it is impossible to directly detect them using visual measurements such as the Global Positioning System (GNSS) or general unmanned aerial vehicles. Moreover, natural caves often have water flow distribution, are filled with harmful gases or have safety hazards such as falling rocks and collapses. It is very difficult or impossible for personnel to enter the cave for on-site measurement. Artificial caves such as drill wells and pipelines are often unable to conduct on-site detection by personnel due to reasons such as narrow space. Therefore, except for mines and a few caves that allow personnel to enter under good conditions, in most cases, cave exploration relies on indirect detection mainly using geophysical exploration and direct unmanned detection using in-entry electronic equipment.

[0003] Geophysical exploration methods for cave exploration include refraction or reflection seismic wave method, resistivity method, electrical profiling method, acoustic wave measurement, natural electric field measurement, etc. Since geophysical exploration measurements are carried out from the surface or air of the measured area, basic information such as the buried position and distribution characteristics of the cave can be obtained, which is easy to operate and has high safety, so it is widely used in practice. However, due to the complexity of the influence of the formation structure on echo signals such as electricity, sound, and magnetism, the results of geophysical exploration measurements inevitably have errors and it is difficult to reveal the structural details and physical conditions of the cave.

[0004] With the increasing maturity of the Inertial Navigation System (INS) technology and its increasingly wide application, inertial measurement units (IMUs) based on MEMS have been gradually integrated into equipment such as mine machinery, unmanned vehicles, and robots for direct detection activities of artificial caves such as mine equipment positioning and tracking, pipeline mapping, and troubleshooting and safety hazard investigation of mine pit equipment. However, compared with artificial caves with regular shapes, flat ground, and determined structures, natural caves have messy structures, multiple channels, uneven ground, are partially or completely submerged in water, and the cave extension is uncertain. Existing unmanned vehicles, robots, etc. are often unable to perform well in natural caves due to passability and waterproof problems, resulting in difficulty in effectively detecting natural caves.

[0005] At present, in order to effectively detect natural caves, amphibious drones are mostly used to penetrate into natural caves for data collection, so as to improve their passability in water and waterless areas of natural caves. However, the existing amphibious drones adopt a four-axis airframe layout, which makes the aspect ratio of the airframe of the amphibious drone relatively large, that is, the airframe is relatively wide. This not only reduces its passability in narrow channels of natural caves, but also the rotors are located outside the airframe and are prone to collide with the rock wall and cause damage, resulting in poor stability of the drone for detecting natural caves. Summary of the Invention

[0006] In view of this, the present invention provides an amphibious drone for detecting natural caves to solve the deficiencies in the prior art. The present invention can improve the passability of the drone in narrow channels of natural caves, and avoid damage caused by the collision of the rotors with the rock wall, thereby improving the stability of the amphibious drone for detecting natural caves.

[0007] The technical solution of the present invention is: an amphibious drone for detecting natural caves, including a housing and a duct vertically opened at the center of the housing. The duct runs through. The single-axis rotor mechanism includes a bracket, and two rotary power elements and rotors arranged on the bracket. The bracket is arranged in the duct and connected to the housing. The two rotary power elements are arranged on the upper and lower sides of the bracket. The output shafts of the rotary power elements are respectively coaxial with the center line of the duct. The two rotors are respectively sleeved on the output shafts of the rotary power elements to drive the two rotors to rotate in opposite directions, so as to drive the drone to move in the air or underwater. A plurality of anti-collision bars are respectively arranged at equal intervals on the upper and lower sides of the housing and are located outside both ends of the duct. The anti-collision bars are arc-shaped and their two ends are connected to the housing to protect the two rotors.

[0008] Preferably, the bracket includes: a roll power element, a roll shaft and a mounting seat. The roll shaft is horizontally arranged in the duct. The roll shaft is rotationally connected to the housing around its circumference. The roll power element is fixed on the housing, and its output shaft is connected to the roll shaft to drive the roll shaft to rotate. The mounting seat is sleeved and fixed in the middle of the roll shaft. The two rotary power elements are respectively fixed on the upper and lower sides of the mounting seat.

[0009] Preferably, the bracket further includes: a pitch axis ring, two connecting shafts and a pitch power element. The pitch axis ring is arranged in the duct and is coaxial with its center line. The roll shaft is located inside the pitch axis ring. The two ends of the roll shaft are rotationally connected to the pitch axis ring around its circumference. The roll power element is fixed on the pitch axis ring. The two connecting shafts are horizontally arranged between the pitch axis ring and the inner wall of the duct and are coaxial with each other. The connecting shafts are perpendicular to the roll shaft. One end of the connecting shaft is fixedly connected to the pitch axis ring, and the other end is rotationally connected to the housing around the circumference of the connecting shaft. The pitch power element is fixed on the housing, and its output shaft is connected to one of the connecting shafts to drive the connecting shaft to rotate.

[0010] Preferably, the cross section of the shell is elliptical, and the major axis of the ellipse is coaxially arranged with the rolling axis.

[0011] Preferably, the multiple anti-collision bars located on the lower side of the shell are replaced by a landing gear, which includes: a plurality of support rods and connecting cross bars, the multiple support rods are vertically arranged at equal intervals around the outside of the center line of the duct, one end of the support rod is fixedly connected to the lower side of the shell, and the multiple connecting cross bars are fixed to the other end of the support rod in a one-to-one correspondence along the radial direction of the duct.

[0012] Preferably, a winder is provided on the outer side of the multiple support rods and is rotatably connected thereto, the winder is located on the upper side of the connecting cross bar, an optoelectronic composite cable is wound on the winder, one end of the optoelectronic composite cable extends into the interior of the shell and is connected thereto, and the other end is connected to an external data acquisition device, a winding power element is provided on the support rod, and an output end of the winding power element is connected to the winder to drive the winder to rotate to wind or release the optoelectronic composite cable.

[0013] Preferably, the wire winder comprises: a plurality of structural rings and vertical poles, the plurality of structural rings are vertically equidistantly sleeved on the outside of a plurality of supporting poles and abutted therewith, a plurality of vertical poles are vertically equidistantly arranged around the plurality of structural rings and are fixedly connected therewith, the lowest structural ring is located on the upper side of the connecting cross bar and abutted therewith, and the output shaft of the winding power element is rotatably connected to the lowest structural ring through a gear and a gear ring mechanism.

[0014] Preferably, multiple support rods are respectively provided with multiple lateral rollers at equal intervals along their length directions and are rotatably connected to the support rods, the lateral rollers abut against the structural rings, multiple connecting cross rods are respectively provided with load-bearing rollers on the sides away from each other and are rotatably connected to the connecting cross rods, the load-bearing rollers abut against the lowermost structural ring, the upper ends of the vertical rods extending out of the structural rings are respectively provided with top rollers and are rotatably connected to the vertical rods, and the top rollers abut against the lower side of the shell.

[0015] Preferably, the sides of the multiple support rods away from the shell are inclined toward the center of the duct respectively, and the wire winder also includes: a wire blocking ring and a plurality of wire blocking rods, the wire blocking ring is arranged on the outside of the structural ring close to the connecting cross bar, the wire blocking ring is coaxial with the center line of the structural ring, and the plurality of wire blocking rods are horizontally connected between the wire blocking ring and the structural ring at equal intervals.

[0016] Preferably, it also includes: a slip ring mounting seat and a photoelectric slip ring, the slip ring mounting seat is fixedly arranged at one end of a plurality of connecting cross bars close to each other, the photoelectric slip ring is passed through the slip ring mounting seat and fixedly connected thereto, the photoelectric slip ring has a fixed end and a movable end at the top and bottom, photoelectric signals are transmitted between the fixed end and the movable end, the fixed end is connected to the inside of the shell through a section of photoelectric composite cable, and the movable end is connected to one end of the photoelectric composite cable wound on a winder.

[0017] Compared with the prior art, a natural cave exploration amphibious drone provided by the present invention uses a housing and a duct at its center in cooperation with a bracket, a rotary power element, a rotor, and an anti-collision bar of a single-axis rotor mechanism. The single axis drives two rotors to rotate to provide power for the drone, thereby driving the drone to move in the air or underwater. Moreover, the drone has a small aspect ratio, and the small body can improve the passability of the drone in the narrow passages of natural caves. The anti-collision bar is used to protect the rotors at both ends of the duct, avoiding damage caused by the collision of the rotors with the rock wall, and improving the stability of the amphibious drone for natural cave exploration. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a perspective view of the amphibious drone of the present invention from the first perspective; Figure 2 is a perspective view of the amphibious drone of the present invention from the second perspective; Figure 3 is an exploded view of the amphibious drone of the present invention; Figure 4 is a schematic structural view of the upper shell of the present invention; Figure 5 is a schematic structural view of the inner plate of the present invention; Figure 6 is a schematic structural view of the lower shell of the present invention; Figure 7 is a schematic view of the stereoscopic camera assembly of the present invention; Figure 8 is a schematic view of the pressure and temperature detection assembly of the present invention; Figure 9 is a schematic view of the amphibious drone of the present invention connected to an external data acquisition device; Figure 10 is a schematic view of the external data acquisition device of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The present invention provides a natural cave exploration amphibious drone. The following combines Figures 1 to 10 the schematic structural views to describe the present invention.

[0020] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the technical solutions of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0021] The existing cave detection technologies mainly include two aspects: indirect detection and direct detection. Indirect detection technology mainly focuses on geophysical exploration. The geophysical exploration methods for cave detection include refraction or reflection seismic wave method, resistivity method, electrical profiling method, acoustic wave measurement, natural electric field measurement, etc. Due to the complexity of the influence of stratum structure on echo signals such as electricity, sound, and magnetism, as well as the inherent noise and errors of geophysical exploration equipment, the interpretation of geophysical exploration measurement results needs to combine the echo characteristics of different geophysical exploration methods. Professional interpretation techniques are required and it has a certain degree of subjectivity. Therefore, significant errors or even interpretation errors are inevitably present. At the same time, it is difficult for geophysical exploration methods to reveal the structural details and physical conditions of caves. For caves in specific situations, targeted indirect detection techniques can also be used to obtain specific cave parameters. For example, when studying the characteristics of underground river confluence, the method of releasing tracers (fluorescent tracers, salts, etc.) can be used. By analyzing the characteristics of the change of tracer concentration with time at the outcrop of the underground river at regular intervals, the average flow velocity, solute residence time, tributary confluence situation, etc. of the underground river can be studied. Only partial physical characteristics of the cave can be understood by such methods and significant errors exist.

[0022] Direct detection technology is also divided into three aspects. On the one hand, a powered vehicle or robot with inertial navigation function is used to enter the cave for structure detection, equipment positioning, or physical measurement, etc. However, the current such devices are all designed for artificial caves in specific situations, such as mine equipment positioning and tracking, pipeline mapping, troubleshooting and safety hazard investigation of mine pit equipment, etc., and cannot be applied to natural caves with more severe terrain, hydrology, and physical environments. On the second hand, on the premise of mastering the cave distribution characteristics according to the geophysical exploration measurement method, the drilling method can be used to directly understand the internal characteristics of the cave. However, this method can only understand the local characteristics of the cave and the cost is high.

[0023] Existing devices applicable to natural cave exploration, such as the authorized announcement number: CN222179853U, a new type of cave mapping drone, adopts a conventional four-axis drone layout. It mainly improves the passability of the drone in narrow spaces by using an energy-absorbing protective cover and improved rotatable arms; the authorized announcement number: CN105799891A, an underwater drone, uses a symmetric four-propeller thruster to drive a sealed body to achieve underwater unmanned exploration, and its main structure is similar to the four-rotor drone layout. Although the above two unmanned exploration technologies can conduct natural cave unmanned exploration, they are difficult to meet the actual needs of natural cave exploration, mainly manifested in: the body layout of the four-axis makes the aspect ratio of the body size of the detection device relatively large, that is, the body is wider, reducing its passability in narrow channels; at the same time, the high-speed rotating propulsion device is located outside the body and is easy to collide with the rock wall, and anti-collision measures must be taken, which further increases the width of the body, resulting in the detection ability and passability in natural caves being difficult to meet the practical needs of scientific research, disaster prevention, engineering construction, adventure and entertainment, etc.

[0024] Based on this, a natural cave exploration amphibious drone is provided in this embodiment. Referring to Figure 1 , Figure 1 is a perspective view of the amphibious drone in the first perspective of this embodiment. A natural cave exploration amphibious drone includes a housing 1 and a duct vertically opened at the center of the housing 1. The duct runs through. The single-axis rotor mechanism includes a bracket and two rotary power elements 21 and rotors 22 arranged on the bracket. The bracket is arranged in the duct and connected to the housing 1. The two rotary power elements 21 are arranged on the upper and lower sides of the bracket. The output shafts of the rotary power elements 21 are respectively coaxial with the center line of the duct. The two rotors 22 are sleeved on the output shafts of the rotary power elements 21 one by one to drive the two rotors 22 to rotate in opposite directions, so as to drive the drone to move in the air or underwater. A plurality of anti-collision bars 6 are respectively arranged at equal intervals on the upper and lower sides of the housing 1 and are located outside both ends of the duct. The anti-collision bars 6 are arc-shaped and their two ends are connected to the housing 1 to protect the two rotors 22.

[0025] In the amphibious drone of this embodiment, the two rotary power elements 21 on the bracket drive the two rotors 22 to rotate in opposite directions, realizing the single-axis structure of the drone, which can make the drone have a relatively large aspect ratio, make the body relatively narrow, and is conducive to passing through the narrow channels in the cave. The forward and reverse rotors 22 provide flight or submersible power for the drone. By controlling the two rotary power elements 21 to rotate at different speeds, the drone can turn in place. Then, the anti-collision bars 6 are used to protect the two rotors 22 at both ends of the duct, avoiding the damage caused by the collision between the rotors and the rock wall when the drone moves in the cave, and improving the stability of the amphibious drone for natural cave exploration.

[0026] Specifically, the rotary power element 21 in this embodiment can use a motor.

[0027] Referring to Figure 3 , Figure 1 which is the explosion diagram of the amphibious UAV in this embodiment. Specifically, in this embodiment, the housing 1 is hermetically installed by an upper shell 2, an inner plate 3 and a lower shell 4. Referring to Figure 4 , Figure 1 which is the structural schematic diagram of the upper shell in this embodiment. A propeller upper duct 5 is opened in the center of the upper shell 2. The upper shell 2 and the inner plate 3 are waterproof and hermetically connected by a sealing strip and fastening screws. A propeller mounting hole 10 concentric and of the same diameter as the propeller upper duct 5 is opened in the center of the inner plate 3. The inner plate 3 and the lower shell 4 are waterproof and hermetically connected by a sealing strip and fastening screws. A propeller lower duct 31 concentric and of the same diameter as the propeller upper duct 5 is opened in the center of the lower shell 4. The outer edges of the upper shell 2, the inner plate 3 and the lower shell 4 are flush. At the same time, the propeller upper duct 5 of the upper shell 2, the propeller mounting hole 10 of the inner plate 3 and the propeller lower duct 31 of the lower shell 4 together form a duct.

[0028] Existing devices applicable to natural cave detection, such as the UAVs disclosed in CN222179853U and CN105799891A, have the problem that they cannot carry out detection in both water and waterless spaces at the same time. In this embodiment, the housing of the amphibious UAV adopts a sealed structure, which can enable the UAV to be used for scientific detection of the structure and physical environment of waterless or water-containing natural caves, making the application scenarios of the UAV more extensive.

[0029] Specifically, in this embodiment, a number of arched anti-collision bars 6 extending longitudinally along the UAV are installed outside the upper shell 2 at the outer side of the upper duct 5. The anti-collision bars 6 are made of a semi-flexible material with a certain yield strength, which can provide effective buffering to protect the UAV when the UAV collides with the rock at the top of the cave.

[0030] As a further optimization scheme, in this embodiment, the bracket includes: a roll power element 17, a roll shaft 18 and a mounting seat 20. The roll shaft 18 is horizontally arranged in the duct. The roll shaft 18 is rotationally connected to the housing 1 around its circumference. The roll power element 17 is fixedly arranged on the housing 1, and its output shaft is connected to the roll shaft 18 to drive the roll shaft 18 to rotate. The mounting seat 20 is sleeved and fixed in the middle of the roll shaft 18. Two rotary power elements 21 are respectively fixed on the upper and lower sides of the mounting seat 20.

[0031] In this embodiment, the bracket includes a roll power element 17, a roll shaft 18, and a mounting base 20. Two rotary power elements 21 are respectively fixed on the upper and lower sides of the mounting base 20, so that the roll power element 17 and the roll shaft 18 can drive the two rotary power elements 21 and the rotor 22 as a whole to rotate by ±30°. This can cause the rotary power element 21 and the rotor 22 to tilt left or right synchronously, so that the UAV can shift left or right.

[0032] Specifically, the roll power element 17 in this embodiment can use a motor.

[0033] As a further optimization scheme, the bracket in this embodiment further includes: a pitch axis ring 12, two connecting shafts 15, and a pitch power element 16. The pitch axis ring 12 is arranged in the duct and coaxial with its center line. The roll shaft 18 is located inside the pitch axis ring 12. The two ends of the roll shaft 18 are rotationally connected to the pitch axis ring 12 around its circumference. The roll power element 17 is fixedly arranged on the pitch axis ring 12. The two connecting shafts 15 are horizontally arranged between the pitch axis ring 12 and the inner wall of the duct and are coaxial with each other. The connecting shaft 15 is perpendicular to the roll shaft 18. One end of the connecting shaft 15 is fixedly connected to the pitch axis ring 12, and the other end is rotationally connected to the housing 1 around the circumference of the connecting shaft 15. The pitch power element 16 is fixedly arranged on the housing 1, and its output shaft is connected to one of the connecting shafts 15 to drive the connecting shaft 15 to rotate.

[0034] In this embodiment, through the cooperation of the pitch axis ring 12, the two connecting shafts 15, and the pitch power element 16, the pitch power element 16 can drive the pitch axis ring 12 to rotate around the connecting shaft 15, so as to drive the roll shaft 18, the mounting base 20, and the two rotary power elements 21 and the rotor 22 as a whole to rotate by ±30°, so as to drive the rotary power element 21 and the rotor 22 to deflect in the front-rear direction, providing power for the UAV to move forward or backward, and realizing the forward or backward movement of the UAV.

[0035] Specifically, in this embodiment, a pitch axis mounting control hole 11 is opened on the transverse side of the inner plate 3 located at the propeller mounting hole 10. The pitch axis ring 12 is concentrically installed with the propeller mounting hole 10. One of the connecting shafts 15 outside the pitch axis ring 12 is inserted into the pitch axis mounting seat 14 provided on the inner wall of the propeller mounting hole 10 through a mounting bearing. The other connecting shaft 15 outside the pitch axis ring 12 passes through the inner wall of the propeller mounting hole 10 and extends into the pitch axis mounting control hole 11. A waterproof seal is provided between the connecting shaft 15 and the inner wall of the propeller mounting hole 10. The pitch power element 16 can cause the pitch axis ring 12 to rotate by ±30 degrees around the circumference of its connecting shaft 15 by pushing and pulling the rudder angle fixed on the connecting shaft 15.

[0036] Specifically, in this embodiment, the pitch axis ring 12 is fixedly installed with a roll power element 17 on one side in the forward direction of the UAV. The output shaft end of the roll power element 17 is fixedly hinged to one end of the roll shaft 18, and the other end of the roll shaft 18 is inserted into the roll shaft mounting seat 19 on the pitch axis ring 12 through a bearing.

[0037] The UAVs in the above two embodiments use a single-axis double-rotor to provide power, and then rotate the pitch axis ring 12 and the roll shaft 18 by ±30 degrees, so that the two rotors rotate within a certain angle, enabling the UAV to move forward and backward and shift left and right. By manipulating the upper and lower rotors to rotate at different speeds, the UAV can turn in place. This operation method eliminates the stability problems that multi-axis UAVs need to maintain due to the lift difference between axes, is easier to operate, and further improves the stability of the amphibious UAV for detecting natural caves.

[0038] As a further optimization scheme, in this embodiment, the cross-section of the housing 1 is elliptical, and the major axis of the ellipse is coaxially arranged with the roll shaft 18.

[0039] In this embodiment, the cross-section of the housing 1 is elliptical, and the major axis of the ellipse is coaxially arranged with the roll shaft 18. That is, when the roll shaft 18 rotates by ±30 degrees, the UAV shifts left or right, and when the pitch axis ring 12 rotates by ±30 degrees, the UAV shifts forward or backward. And the major axis of the ellipse is the forward direction of the UAV, making the entire UAV move in a fusiform shape, which is beneficial for the amphibious UAV to pass through the narrow channels in natural caves and further improves the stability of the amphibious UAV for detecting natural caves.

[0040] Refer to Figure 2 , Figure 1 As the three-dimensional view of the amphibious UAV in the second perspective of this embodiment, as a further optimization scheme, in this embodiment, multiple anti-collision bars 6 located on the lower side of the housing 1 are replaced by landing gears. The landing gear includes: multiple support rods 35 and connecting crossbars 37. The multiple support rods 35 are vertically arranged at equal intervals around the center line of the duct outside, one end of the support rod 35 is fixedly connected to the lower side of the housing 1, and the multiple connecting crossbars 37 are fixedly arranged at the other ends of the support rods 35 one by one along the radial direction of the duct.

[0041] In this embodiment, the landing gear composed of multiple support rods 35 and connecting crossbars 37 replaces the multiple anti-collision bars 6 located on the lower side of the housing 1, which can protect the rotor 22 while also serving as the landing gear of the entire UAV.

[0042] In the prior art, devices applicable to natural cave exploration, such as the unmanned aerial vehicle disclosed in CN222179853U, have the following problems: The main driving power source is the on-board battery, and the detection time and depth are limited by the endurance time of the unmanned aerial vehicle. For example, if the unmanned aerial vehicle falls in the cave due to battery depletion, collision, electronic or mechanical failure, it cannot be rescued, resulting in equipment loss. Due to the electromagnetic shielding effect of the underlying layer, detection data can only be stored in the on-board equipment. In the event of a crash accident, not only the unmanned aerial vehicle is lost, but also the detection data is lost synchronously. Although in the prior art CN105799891A, the underwater unmanned aerial vehicle adopts a power insurance measure of connecting an external power cord to the on-board battery, the power supply method of dual internal and external power sources ensures power supply and enables remote control and data synchronous transmission, but it additionally increases the working weight and forward resistance of the unmanned aerial vehicle. At the same time, since its main application scenario is open water, the situation of cable jamming and entanglement rarely occurs, while the natural cave itself is complex, and the external cable is easily jammed in the rock crevices.

[0043] Based on this, in this embodiment, a solution is proposed. In this embodiment, a wire winder 49 is sleeved outside and rotatably connected to a plurality of support rods 35. The wire winder 49 is located above the connecting cross bar 37. An optical and electrical composite cable 30 is wound on the wire winder 49. One end of the optical and electrical composite cable 30 extends into the housing 1 and is connected thereto, and the other end is connected to an external data acquisition device. A wire winding power element 48 is provided on the support rod 35. The output end of the wire winding power element 48 is connected to the wire winder 49 to drive the wire winder 49 to rotate to wind or release the optical and electrical composite cable 30.

[0044] In this embodiment, the wire winder 49 is installed on a plurality of support rods 35 of the landing gear. The wire winding power element 48 is used to drive the wire winder 49 to rotate to wind or release the optical and electrical composite cable 30. When the optical and electrical composite cable 30 connecting the unmanned aerial vehicle to the external data acquisition device is jammed in the rock crevices during the flight of the unmanned aerial vehicle, the wire winding power element 48 can be controlled to drive the wire winder 49 to rotate for wire winding operation, so that the unmanned aerial vehicle retreats to the jamming point of the optical and electrical composite cable 30 and the rock crevices. Then, by controlling the up, down, left, and right movement of the unmanned aerial vehicle and assisted by the external dragging of the optical and electrical composite cable, the optical and electrical composite cable can be disengaged from the jamming point. Using the wire winder 49 as a measure for the unmanned aerial vehicle cable to get rid of jamming and self-rescue greatly increases the detection distance of the unmanned aerial vehicle in the cave.

[0045] The wire winder 49 in the above embodiment can be used for the UAV to get out of trouble. Since there are many scattered stones and the cave walls are uneven in natural caves, after the wire-controlled UAV enters, the towed cable is easily stuck in the gaps between the stones or the rock walls, hindering the forward movement of the UAV. To enable the UAV to get out of the stuck position, it is necessary to use the wire winder to wind back the cable and try to shorten the distance between the UAV and the stuck position. In this way, by maneuvering the UAV up, down, left, and right, the cable can be towed out of the stuck position to achieve getting out of trouble. If the cable between the UAV and the stuck position is too long, the UAV cannot directly exert force on the stuck cable, so it is necessary to first shorten it through the wire winder.

[0046] In addition, in the above embodiment, when the UAV is moving and detecting normally, the optoelectronic composite cable 30 can be wound around the wire winder 49 only once or not at all. The optoelectronic composite cable 30 led out from the UAV is fixed to one side of the wire winder 49 using a wire clamp, and the wire winder can smoothly wind the optoelectronic composite cable 30 during rotation.

[0047] In this embodiment, the wire-controlled method of the optoelectronic composite cable 30 is used to drive the amphibious UAV to detect the structure and environment of natural caves. The high-voltage AC cable power supply method and optical signals are used for data transmission, making the power line in the optoelectronic composite cable 30 thinner and lighter. While reducing the weight of the UAV, it eliminates the detection distance and time limitations caused by the UAV battery power supply. The fiber optic data transmission ensures the reliable transmission of control and measurement data. The UAV transmits the detection data to the outside of the cave in real time through the optoelectronic composite cable 30, enabling real-time mapping of the cave structure and physical environment, and avoiding data loss caused by the UAV being unable to tow out due to data being stored in the UAV's offline storage.

[0048] Specifically, a power module 32 is arranged in the middle of the rear side of the lower shell. The power module 32 accesses the high-voltage alternating current transmitted through the optoelectronic composite cable 30 and supplies power to each electrical device of the UAV. An electronic speed controller 33 is arranged on one side of the rear part of the lower shell 4 to provide power for the motor. The power supply line and signal line output by the electronic speed controller 33 pass through the side wall of the lower duct 31 of the thruster and are respectively connected to two rotary power elements 21 (motors) along the pitch axis ring 12 and the roll axis 18. The line through holes on the side wall of the lower duct 31 of the thruster are waterproof sealed. A number of first mounting holes and second mounting holes are transversely opened in the middle of the lower shell 4, and the arrangement method is the same as that of the upper shell 2. The underwater acoustic transducers 8 and the air acoustic transducers 9 are respectively installed, and all the underwater acoustic transducers 8 and the air acoustic transducers 9 are connected to the ultrasonic drive board 34 at the front part inside the lower shell 4 through a wire harness.

[0049] The underwater acoustic transducers 8 in the above embodiment can use low-frequency models with a frequency less than 800K Hz and a measurement range of 0.3 - 30 meters, such as: DWY-650-01E. The air acoustic transducers 9 can use 40 - 60K Hz sensors with a measurement range of 0.2 - 15 meters, such as: DYA-40-12E.

[0050] For a further optimized solution, in this embodiment, the wire winder 49 includes: a plurality of structural rings 50 and a vertical rod 51. The plurality of structural rings 50 are sleeved on the outer sides of the plurality of support rods 35 at equal intervals in the vertical direction and are in contact with them. The plurality of vertical rods 51 are arranged at equal intervals around and penetrate through the plurality of structural rings 50 in the vertical direction and are fixedly connected to them. The lowermost structural ring 50 is located above the connecting cross bar 37 and is in contact with it. The output shaft of the wire winding power element 48 is rotationally connected to the lowermost structural ring 50 through a gear and a gear ring mechanism.

[0051] In this embodiment, the wire winder 49 is a rotatable assembly at the bottom of the lower housing 4. The wire winder 49 formed by fixedly connecting a plurality of structural rings 50 with a plurality of vertical rods 51 can wind the optical and electrical composite cable 30, and at the same time further reduce the weight of the unmanned aerial vehicle. In addition, the wire winder 49 also serves as the outer part of the landing gear to improve its strength and enhance the stability of the unmanned aerial vehicle during takeoff and landing.

[0052] The lower ends of the plurality of vertical rods 51 are fixedly connected by an annular gear ring 53. An arc-shaped shaft 46 is connected between the ends of any two support rods 35 away from the lower housing 4. A wire winding motor mounting seat 47 is sleeved in the middle of the arc-shaped shaft 46. The wire winding power element 48 is fixed on the wire winding motor mounting seat 47. The wire winding motor 48 meshes with the annular gear ring 53 through a gear, so as to drive the wire winder 49 composed of the plurality of structural rings 50 and the vertical rods 51 to rotate, so as to realize the operation of winding or releasing the optical and electrical composite cable 30.

[0053] Refer to Figure 6 , Figure 6 As a structural schematic diagram of the lower housing of this embodiment, as a further optimized solution, in this embodiment, a plurality of lateral rollers 36 are sleeved on the plurality of support rods 35 at equal intervals along their lengths and are rotationally connected to the support rods 35. The lateral rollers 36 are in contact with the structural rings 50. Load-carrying rollers 39 are sleeved on the mutually remote sides of the plurality of connecting cross bars 37 and are rotationally connected to the connecting cross bars 37. The load-carrying rollers 39 are in contact with the lowermost structural ring 50. The upper ends of the vertical rods 51 extend out of the structural rings 50 and are respectively sleeved with top rollers 52 and are rotationally connected to the vertical rods 51. The top rollers 52 are in contact with the lower side of the housing 1.

[0054] In this embodiment, the support rod 35 is provided with lateral rollers 36 arranged at intervals and having the same number as the structural rings 50. For example, 2 to 3 lateral rollers 36 are installed at intervals on the support rod 35. Load-bearing rollers 39 are respectively installed on the sides of the plurality of connecting crossbars 37 away from each other. At the upper ends of the vertical rods 51 extending out of the structural rings 50, top rollers 52 are respectively sleeved. The outer sides of the lateral rollers 36 are in tangential contact with the structural rings 50, and the micro rollers 52 are in tangential contact with the bottom surface of the lower housing 4. The annular gear ring 53 is placed on the plurality of load-bearing rollers 39. Under the support of the load-bearing rollers 39 and the limitation of the lateral rollers 36 and the micro rollers 52, the wire winder 49 can rotate around the center line of the duct, and the friction of the rotation of the wire winder 49 can be reduced.

[0055] As a further optimization scheme, in this embodiment, the sides of the plurality of support rods 35 away from the housing 1 are respectively inclined towards the center of the duct. The wire winder 49 further includes: a wire blocking ring 55 and a plurality of wire blocking rods 54. The wire blocking ring 55 is sleeved on the outer side of the structural ring 50 close to the connecting crossbar 37. The wire blocking ring 55 is coaxial with the center line of the structural ring 50. The plurality of wire blocking rods 54 are horizontally connected at equal intervals between the wire blocking ring 55 and the structural ring 50.

[0056] In this embodiment, the sides of the plurality of support rods 35 away from the lower housing 4 are respectively inclined towards the center of the duct by 5 to 20 degrees, so that the outer diameter of the structural ring 50 of the wire winder 49 decreases from top to bottom, and the vertical rods 51 are also inclined, so as to avoid affecting the measurement of the underwater acoustic transducer 8 and the air acoustic transducer 9 at the bottom of the lower housing 4.

[0057] In addition, after the above settings are made for the support rod 35, the structural ring 50 and the vertical rod 51 in this embodiment, in order to prevent the optoelectronic composite cable 30 wound on the wire winder 49 from falling off, a plurality of wire blocking rods 54 are arranged on the outer side of the structural ring 50 close to the connecting crossbar 37 or on the outer side of the annular gear ring 53. The other ends of the plurality of wire blocking rods 54 are fixedly connected to the wire blocking ring 55 to limit the optoelectronic composite cable 30 wound on the wire winder 49 to prevent it from falling off and improve the stability of the wire winder 49.

[0058] As a further optimization scheme, in this embodiment, it further includes: a slip ring mounting seat 38 and an optoelectronic slip ring 40. The slip ring mounting seat 38 is fixedly arranged at one end of the plurality of connecting crossbars 37 close to each other. The optoelectronic slip ring 40 is passed through the slip ring mounting seat 38 and fixedly connected thereto. The upper and lower parts of the optoelectronic slip ring 40 have a fixed end 41 and a movable end 42. Optoelectronic signals are transmitted between the fixed end 41 and the movable end 42. The fixed end 41 is connected to the inside of the housing 1 through a section of optoelectronic composite cable 30, and the movable end 42 is connected to one end of the optoelectronic composite cable 30 coiled on the wire winder 49.

[0059] In this embodiment, one end of the slip ring mounting seat 38 close to the plurality of connecting cross bars 37 is fixedly connected, and then the fiber optic slip ring 40 is concentrically fixed on the slip ring mounting seat 38. Thus, the fixed end 41 of the fiber optic slip ring 40 is connected to the inside of the housing 1 through an optical and electrical composite cable 30, and the movable end 42 of the fiber optic slip ring 40 is connected to one end of the optical and electrical composite cable 30 wound around the wire winder 49. Therefore, when the wire winder 49 winds the optical and electrical composite cable 30, the movable end 42 of the fiber optic slip ring 40 rotates synchronously with the wire winder 49, enabling the wire winder 49 to wind or release the optical and electrical composite cable 30 smoothly.

[0060] Specifically, the optical and electrical composite cable 30 led out from the fixed end 41 of the fiber optic slip ring 40 enters the inside of the UAV through the bottom of the lower housing 4 and is divided into two strands, namely an optical fiber and a power line, which are respectively connected to the optical terminal 28 and the power module 32; the optical and electrical composite cable 30 led out from the movable end 42 of the fiber optic slip ring 40 is wound and fixed on the wire winder 49, led out through the cable guiding ring 44 fixed to the rear side of the bottom of the lower housing 4, and then wound around the external winding disc 45.

[0061] Refer to Figure 7 , Figure 7 is a schematic diagram of the stereo camera assembly of this embodiment. For the natural cave exploration amphibious UAV of the present invention, a stereo camera assembly 7 is respectively installed at both ends (at both ends of the long axis) on the outer side of the upper housing 2. The stereo camera assembly 7 includes: a fixed-focus camera 56, an infrared illumination lamp 57, and an LED illumination lamp 58. The LED illumination lamp 58 is located in the middle, and the fixed-focus camera 56 and the infrared illumination lamp 57 are symmetrically arranged on both sides of the LED illumination lamp 58. A plurality of first mounting holes and second mounting holes are respectively opened at the front, middle, rear, etc. positions of the upper housing 2 to respectively install the underwater acoustic transducer 8 and the air acoustic transducer 9.

[0062] The fixed-focus camera 56 in the above embodiment can adopt a low-light 1 / 3” 2.8mm focal length camera module, such as the IMX226 module.

[0063] The stereo camera assembly 7 can obtain a large amount of good cave structure data in a waterless space with good lighting. At the same time, the photo images can provide rich cave texture details. In a clear water environment, the stereo camera assembly 7 can still obtain a certain amount of structure data, especially the terrain data at the bottom of the water, under good lighting conditions. In a turbid water body with a large amount of suspended sediment, the detection distance of the stereo camera assembly 7 is severely limited and the operation is poor.

[0064] The underwater acoustic transducer 8 can only generate ranging signals when it is in contact with water and cannot work properly in air. In turbid water with a large amount of suspended sediment, if the size of the suspended particulate matter is smaller than the ultrasonic wavelength, the underwater acoustic transducer 8 can send back the correct distance signals of the bottom and the rock walls on both sides. The air acoustic transducer 9 can only generate ranging signals in air and cannot work properly in water. To obtain accurate ranging data, both the air acoustic transducer 9 and the underwater acoustic transducer 8 need to be corrected using the data of the temperature sensor 66.

[0065] Referring to Figure 5 , Figure 5 is a schematic structural diagram of the inner plate of this embodiment. In the above embodiment, a lidar 25, a UAV flight control board 26, and a MEMS inertial navigation measurement unit IMU27 are vertically installed at the front end of the inner plate 3. The lidar 25, the UAV flight control board 26, and the MEMS inertial navigation measurement unit IMU27 are installed along the long axis at the front part of the inner plate 3, and the optical terminal 28 is installed in the middle at the rear side of the inner plate 3. The optical signal of the optical terminal is connected to the optoelectronic composite cable 30 through the optical cable 29.

[0066] Specifically, the lidar 25 can work well in an air environment without illumination. Selecting a blue or green light radar can obtain effective observation data in a clear water environment, but in turbid water with a large amount of suspended sediment, the lidar cannot obtain effective data. When detecting in turbid water, if none of the structural measurement components can obtain effective data, the UAV can be controlled to move up, down, left, and right in place, and the position data of the amphibious UAV 1 calculated by the MEMS inertial navigation measurement unit IMU27 can be used to mark the current cave contour.

[0067] In the above embodiment, while the MEMS inertial navigation measurement component is performing position calculation using a conventional method, the data of the cable extension length measured in real time can be used for position correction calculation. Using a computer as a data processing terminal for inertial navigation data calculation, stereo image pair calculation, sensor data scanning, etc., real-time three-dimensional mapping of the cave structure and physical environment monitoring can be carried out.

[0068] Referring to Figure 8 , Figure 8This is a schematic diagram of the pressure and temperature detection component in this embodiment. In the above embodiment, the middle part of the outer side of the lower shell 4 is installed with a pressure and temperature detection component 59 through a buckle. A through hole 60 is opened at the front end of the waterproof shell 67 of the pressure and temperature detection component 59, which is beneficial for water flow or air to enter the dynamic pressure water pipe 61. The dynamic pressure sensor 62 is hermetically connected to the dynamic pressure water pipe 61; transverse through holes 63 are opened on both sides of the waterproof shell 67 of the pressure and temperature detection component 59. The two transverse ends of the four-way pipe 64 are respectively connected to the through holes 63, which is beneficial for water flow or air to enter the four-way pipe 64. The static pressure sensor 65 is hermetically connected to the longitudinal front end, and the temperature sensor 66 is hermetically connected to the longitudinal rear end. The carried pressure and temperature detection component integrates the functions of measuring the relative flow velocity of water body, the ambient static pressure, and the ambient temperature, and provides the measurement data of the physical quantities commonly used in natural caves.

[0069] The available range of the above pressure sensor can be a micro pressure transmitter of 0-10 MPa, such as FMTKSG-RLP131M. The temperature sensor 66 can be a high-precision PT100 platinum resistance sensor above 1 / 3B grade.

[0070] During the exploration and scanning process of the amphibious drone, the pressure and temperature detection component 59 synchronously collects the air pressure or water pressure, air temperature or water temperature, and fluid movement speed or water flow in the cave. The principle of the pressure and temperature detection component 59 to obtain the fluid movement speed is the same as that of the pitot tube, both based on Bernoulli's principle. The fluid movement speed is obtained by comparing the differences between the dynamic pressure sensor 62 and the static pressure sensor 65. This movement speed is the movement speed of the amphibious drone 1 relative to the air flow or water flow. By calculating through the MEMS inertial navigation measurement unit IMU27, the movement speed of the amphibious drone can be obtained. Therefore, by adding the movement speed of the amphibious drone and the relative movement speed of the fluid, the movement speed of the fluid relative to the earth coordinate system can be obtained.

[0071] When the drone finishes measuring the cave, the amphibious drone can be assisted by the stereo camera component 7 video to be in a hovering or slow backward state, and the winch 49 can be manually or automatically wound to recover the drone. During the drone recovery process, each sensor and the computer 73 mapping system work normally, and encrypted cave structure data and changing cave physical environment data can be obtained.

[0072] Refer to Figure 10 , Figure 10It is a schematic diagram of the external data acquisition device in this embodiment. One end of the optoelectronic composite cable 30 in the natural cave exploration amphibious drone of the present invention is connected to the amphibious drone that penetrates into the cave, and the other end is coiled on the cable reel 45 placed at the cave entrance. The elastic pressure roller 68 is horizontally arranged on the cable reel 45 along the center line direction of the cable reel 45 and abuts against the outermost layer of the optoelectronic composite cable 30 coiled on the cable reel 45. One end of the elastic pressure roller 68 is connected to the cable length counter 69, and the optical fiber signal is converted into multiple serial signals for output through the external optical terminal 70; the flight control signal is connected to the remote controller 71 to control the flight of the amphibious drone, and the inertial navigation signal, ultrasonic signal, temperature and pressure signal, etc. are connected to the computer 73 through the serial port server 72; the GPS / Beidou signal sensor 74 is connected to the computer 73 to provide the initial position signal.

[0073] In this embodiment, the cable length counter 69 accurately measures the length of the cable extended, which can be used for error correction of the position of the inertial navigation solution carrier.

[0074] A natural cave exploration amphibious drone in the present invention uses an air and water amphibious single-axis drone as a natural cave exploration vehicle, and performs position, attitude and speed calculation through an inertial navigation system (INS) based on MEMS. The drone is equipped with two front and rear stereo cameras to provide a cave stereo image pair and control guidance, equipped with a lidar and ultrasonic sensors to provide structural scanning data of the waterless space, and equipped with multiple underwater ultrasonic sensors to provide structural scanning data of the water space. Stereo image analysis, lidar scanning, and ultrasonic detection simultaneously provide multi-source cave structure data for the computing system. At the same time, sensors such as temperature, pressure, and stress are equipped to provide data information such as temperature, water pressure, and flow rate. The drone is connected to an external power supply, data transmission device and computer through an optoelectronic composite cable for power and data transmission. High-voltage AC power supply not only ensures power supply but also eliminates the weight increase and endurance mileage limitation caused by the drone carrying a battery. At the same time, it allows the use of thinner power supply cables to reduce the weight of the line; the drone is controlled by an external remote controller or computer, and the computer real-time collects various data transmitted back by the drone and external data such as cable extension length and GPS position, and performs three-dimensional mapping of the cave structure, cave environment variables, drone position, etc. after data error. The amphibious drone of the present invention penetrates into natural caves for on-site exploration, can provide direct observation results of cave structures and physical characteristics, solves the problem of large errors in indirect cave exploration by geophysical exploration methods, and also solves the limitation that existing cave exploration equipment can only be applied to specific environments, and can meet the needs of natural cave exploration, underwater exploration, tomb tunnel exploration and other work.

[0075] The natural cave exploration amphibious drone of the present invention can provide complementary multi-source detection data for natural cave structure mapping by using stereo image analysis, lidar scanning, and ultrasonic detection. Through the comparison of multi-source data, it is easy to automatically eliminate abnormal data and form a cave structure point cloud, enabling high-resolution cave structure mapping. In addition, the amphibious drone is easy to manufacture, has a low cost, is light and portable, and is easy to carry and deploy for measurement in the field with poor transportation conditions.

[0076] The implementation process of natural cave exploration based on the natural cave exploration amphibious drone is as follows: Refer to Figure 9 , Figure 9 is a schematic diagram of connecting external data acquisition equipment to the amphibious drone of this embodiment. Unfold each component of this drone at the open entrance of the cave to be detected. Connect one end of the optoelectronic composite cable 30 to the amphibious drone through the elastic pressure roller 68, and the other end's fixed connectors are respectively connected to the optical signal input and high-voltage alternating current input of the external optical terminal 70. The flight control signal output end of the external optical terminal 70 is connected to the remote controller 71. The inertial navigation signal, ultrasonic signal, temperature and pressure signal, etc. are connected to the computer 73 through the serial port server 72. The GPS / Beidou signal sensor 74 is connected to the computer 73. Turn on each device to test whether the connection signal is normal, and perform necessary device initialization and calibration.

[0077] The test items include but are not limited to: whether each connector is tightened; whether the optical signal connection is normal; whether the power supply line is normal; whether the image transmission is normal; whether the lidar scanning is normal; whether the ultrasonic signal is normal; whether the pressure sensor, temperature sensor, fluid velocity measurement, etc. are normal; whether the remote control is normal; whether the tilting of the rotor in the front, rear, left, and right directions is normal.

[0078] The device initialization and calibration include but are not limited to: the conventional initialization and calibration of the on-board gyroscope, accelerometer, and magnetometer of the drone flight control board 26; the conventional initialization and calibration of the on-board gyroscope and accelerometer of the MEMS inertial navigation measurement unit IMU27; the cold start of the GPS / Beidou signal sensor 74.

[0079] After the cold start of the GPS / Beidou signal sensor 74 is completed, wait for more than 5 minutes so that the computer 73 can obtain stable average position coordinates. Use this coordinate as the initial coordinate of the MEMS inertial navigation measurement unit IMU27 of the amphibious drone 1. After ensuring the normal operation of computer data acquisition, analysis, and real-time mapping, according to the video guidance of the stereo camera assembly 7, control the amphibious drone 1 to slowly enter the cave to start data acquisition. By controlling the pitch power element 16, the rudder angle fixed on the connecting shaft 15 can be pushed or pulled to make the pitch axis ring 12 rotate ±30 degrees around its horizontal axis, so as to drive the pitch power element 16 and the rotor 22 to deflect forward and backward, providing power for the drone to move forward or backward; by controlling the roll power element 17 to drive the roll shaft 18 to rotate ±30 degrees, so as to drive the motor and the rotor to deflect left and right, providing power for the drone to deflect left and right; by controlling the two rotary power elements 21 to drive the rotor 22 to rotate at different speeds, the generated rotational torque difference causes the drone to turn.

[0080] During the movement, if the optoelectronic composite cable 30 is stuck in a rock crevice, resulting in the amphibious drone being blocked and unable to move forward, the cable winding power element 48 can be controlled to drive the cable winder 49 to rotate under the image guidance of the stereo camera assembly 7, so that the optoelectronic composite cable 30 is shortened in the direction of the blockage. After reaching the blockage point, under the image guidance of the stereo camera assembly 7, by controlling the amphibious drone to move up, down, forward, backward, left, and right, and at the same time, the operator drags and pulls the optoelectronic composite cable 30 outside the cave, so that the optoelectronic composite cable 30 is disengaged from the blockage point, thus enabling the amphibious drone to get out of trouble.

[0081] The above-disclosed are only the preferred specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any changes that can be thought of by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A natural cave exploration amphibious drone, characterized in that, Comprising: A housing (1) and a duct vertically opened at the center of the housing (1), the duct being disposed therethrough; A single-axis rotor mechanism, comprising: a bracket and two rotary power elements (21) and rotors (22) provided on the bracket, the bracket being disposed in the duct and connected to the housing (1), the two rotary power elements (21) being disposed on the upper and lower sides of the bracket, the output shafts of the rotary power elements (21) being coaxial with the center line of the duct respectively, and the two rotors (22) being sleeved on the output shafts of the rotary power elements (21) in one-to-one correspondence to drive the two rotors (22) to rotate in opposite directions, so as to drive the unmanned aerial vehicle to move in the air or underwater; A plurality of anti-collision bars (6), which are respectively arranged at equal intervals on the upper and lower sides of the housing (1) and are located outside both ends of the duct, the anti-collision bars (6) being arc-shaped and both ends thereof being connected to the housing (1) to protect the two rotors (22).

2. The natural cave exploration amphibious drone according to claim 1, wherein The bracket comprises: a roll power element (17), a roll shaft (18) and a mounting seat (20), the roll shaft (18) being horizontally disposed in the duct, the roll shaft (18) being rotatably connected to the housing (1) around its circumference, the roll power element (17) being fixed on the housing (1), and its output shaft being connected to the roll shaft (18) to drive the roll shaft (18) to rotate, the mounting seat (20) being sleeved and fixed on the middle part of the roll shaft (18), and the two rotary power elements (21) being respectively fixed on the upper and lower sides of the mounting seat (20).

3. The natural cave exploration amphibious drone according to claim 2, wherein, The bracket further comprises: a pitch axis ring (12), two connecting shafts (15) and a pitch power element (16), the pitch axis ring (12) being disposed in the duct and coaxial with its center line, the roll shaft (18) being located inside the pitch axis ring (12), both ends of the roll shaft (18) being rotatably connected to the pitch axis ring (12) around its circumference, the roll power element (17) being fixed on the pitch axis ring (12), the two connecting shafts (15) being horizontally disposed between the pitch axis ring (12) and the inner wall of the duct and being coaxial with each other, the connecting shafts (15) being perpendicular to the roll shaft (18), one end of the connecting shaft (15) being fixedly connected to the pitch axis ring (12), and the other end being rotatably connected to the housing (1) around the circumference of the connecting shaft (15), the pitch power element (16) being fixed on the housing (1), and its output shaft being connected to one of the connecting shafts (15) to drive the connecting shaft (15) to rotate.

4. The natural cave-detecting amphibious drone according to claim 2, wherein, The cross-section of the housing (1) is oval, and the long axis of the oval is coaxially arranged with the roll shaft (18).

5. The natural cave exploration amphibious drone according to claim 1, characterized in that, A plurality of anti-collision bars (6) located on the lower side of the housing (1) are replaced by landing gears, and the landing gears comprise: a plurality of support rods (35) and connecting cross bars (37), the plurality of support rods (35) being vertically arranged at equal intervals around the center line of the duct, one end of the support rod (35) being fixedly connected to the lower side of the housing (1), and the plurality of connecting cross bars (37) being fixedly arranged on the other ends of the support rods (35) in one-to-one correspondence along the radial direction of the duct.

6. The natural cave exploration amphibious drone according to claim 5, characterized in that, A wire winder (49) is sleeved on the outer side of the plurality of support rods (35) and is rotatably connected thereto; the wire winder (49) is located on the upper side of the connecting cross bar (37); a photoelectric composite cable (30) is wound on the wire winder (49); one end of the photoelectric composite cable (30) extends into the interior of the housing (1) and is connected thereto; the other end is connected to an external data acquisition device; a wire winding power element (48) is provided on the support rod (35); an output end of the wire winding power element (48) is connected to the wire winder (49) to drive the wire winder (49) to rotate and wind or release the photoelectric composite cable (30).

7. The natural cave-detecting amphibious drone according to claim 6, characterized in that, The wire winder (49) comprises: a plurality of structural rings (50) and vertical rods (51); the plurality of structural rings (50) are sleeved on the outside of a plurality of support rods (35) at equal intervals in the vertical direction and abut against the support rods (35); the plurality of vertical rods (51) are equidistantly arranged around the plurality of structural rings (50) in the vertical direction and are fixedly connected thereto; the lowest structural ring (50) is located on the upper side of the connecting cross bar (37) and abuts against the connecting cross bar; and the output shaft of the winding power element (48) is rotationally connected to the lowest structural ring (50) via a gear and a gear ring mechanism.

8. The natural cave exploration amphibious drone according to claim 7, characterized in that, A plurality of lateral rollers (36) are sleeved on the plurality of support rods (35) at equal intervals along their length direction and are rotatably connected to the support rods (35); the lateral rollers (36) abut against the structural ring (50); a plurality of connecting cross rods (37) are sleeved on the sides away from each other and are rotatably connected to the connecting cross rods (37); the bearing rollers (39) abut against the lowest structural ring (50); the upper ends of the vertical rods (51) extending out of the structural ring (50) are sleeved with top rollers (52) and are rotatably connected to the vertical rods (51); the top rollers (52) abut against the lower side of the housing (1).

9. The natural cave exploration amphibious drone according to claim 7, characterized in that, The sides of the plurality of support rods (35) away from the shell (1) are inclined toward the center of the duct respectively. The wire winder (49) further comprises: a wire retaining ring (55) and a plurality of wire retaining rods (54). The wire retaining ring (55) is sleeved on the outside of a structural ring (50) close to the connecting cross bar (37). The center lines of the wire retaining ring (55) and the structural ring (50) are coaxial. The plurality of wire retaining rods (54) are horizontally connected at equal intervals between the wire retaining ring (55) and the structural ring (50).

10. The natural cave exploration amphibious drone according to claim 6, characterized in that, Also includes: A slip ring mounting seat (38) and a photoelectric slip ring (40), wherein the slip ring mounting seat (38) is fixedly mounted on one end of a plurality of connecting cross bars (37) close to each other, the photoelectric slip ring (40) is inserted into the slip ring mounting seat (38) and is fixedly connected thereto, the photoelectric slip ring (40) has a fixed end (41) and a movable end (42) at the top and bottom, photoelectric signals are transmitted between the fixed end (41) and the movable end (42), the fixed end (41) is connected to the inside of a housing (1) via a section of a photoelectric composite cable (30), and the movable end (42) is connected to one end of the photoelectric composite cable (30) wound on a winder (49).

Images