A dual-mode unmanned vehicle and a method for switching between modes

Abstract

The application discloses a kind of double navigation state unmanned vehicles and navigation state switching method, belong to marine vehicle technical field, unmanned vehicle includes streamlined shell, attitude adjusting unit is arranged inside shell, one end of shell is underwater fairing head, the other end of shell is water fairing head, still include water filling cavity, water filling and draining assembly, active propeller, retractable wing assembly;Water filling cavity is located inside shell;Water filling and draining assembly is used to fill water in water filling cavity or drain water in water filling cavity;Active propeller is close to underwater fairing head and is arranged, active propeller is used to exert water dynamic propulsive force to unmanned vehicle and be directed to water fairing head;Retractable wing assembly is installed in the side of shell, retractable wing assembly has folding and unfolding attitude.The double navigation state unmanned vehicle of the application overcomes the single navigation state problem of existing surface and underwater unmanned vehicle through innovative design and optimization, and provides more flexible, efficient and multifunctional marine unmanned navigation platform.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of marine unmanned vehicles, and particularly relates to a dual-navigation-state unmanned vehicle and a navigation-state switching method. BACKGROUND

[0002] A marine unmanned vehicle is an autonomous vehicle that does not require human control or operation, and performs various tasks through a pre-set navigation path, sensors, and an autonomous control system. These vehicles are widely used in marine research, marine surveying, resource exploration, marine monitoring, marine environmental protection, and seabed topography mapping. Marine unmanned vehicles can be classified into various types according to their functions and design characteristics, including: surface unmanned vehicles: these vehicles autonomously navigate on the water surface, similar to remote-controlled boats. They are commonly used for tasks such as marine monitoring, measurement, water quality sampling, and can be equipped with cameras and sensors for data collection and monitoring. Underwater unmanned vehicles: these vehicles are autonomous underwater vehicles that perform tasks underwater. They can be used for tasks such as seabed topography mapping, resource exploration, and marine biology research, and are widely used for underwater exploration and underwater archaeology.

[0003] Surface navigation and underwater navigation are two completely different navigation states. In order to meet the needs of future marine multi-space stereoscopic observation, there are some limitations in existing surface and underwater unmanned vehicle technology. Surface unmanned vehicles are mainly based on the technology system of small ships, while underwater unmanned vehicles are based on the technology system of torpedoes and submarines. However, both types of unmanned vehicles can only work continuously in their respective navigation spaces and cannot freely switch between surface and underwater navigation states.

[0004] To achieve the adaptability of unmanned vehicles in both surface and underwater navigation states, a series of technical problems need to be solved. First, the overall shape design of the vehicle must overcome the differences in water dynamics, water resistance, and steering characteristics between surface and underwater navigation. At the same time, the driving method is also a key problem. Existing surface unmanned vehicles usually use propellers or hydrodynamic propulsion systems, but these methods will be limited in underwater efficiency, and new driving methods need to be developed to enable efficient propulsion and driving in both surface and underwater. In addition, the buoyancy and gravity balance requirements of the vehicle in surface and underwater states are different, and existing designs usually only balance for a single navigation state.

[0005] In summary, to achieve the adaptability of unmanned vehicles in both surface and underwater navigation states, comprehensive innovation and breakthroughs are needed in structural design, driving method, weight balance adjustment, energy supply and endurance capability, etc. SUMMARY

[0006] In view of the problems in the prior art, the present application provides a dual-navigation-state unmanned vehicle and a navigation-state switching method to solve the problems of single navigation state, poor adaptability, driving mode and weight characteristic adjustment performance of the dual-navigation-state unmanned vehicle.

[0007] The present application is implemented as follows: a dual-navigation-state unmanned vehicle, comprising a streamlined shell, an attitude adjustment unit arranged inside the shell, characterized in that: one end of the shell is an underwater flow guide head, the other end of the shell is a water surface flow guide head, and the shell further comprises a water filling cavity, a water filling and discharging assembly, a main propeller and a retractable wing assembly; the water filling cavity is arranged inside the shell; the water filling and discharging assembly is used for filling water in the water filling cavity or discharging water in the water filling cavity; the main propeller is arranged close to the underwater flow guide head, and the main propeller is used for applying a water dynamic propelling force to the unmanned vehicle, which is directed to the water surface flow guide head; and the retractable wing assembly is installed on the side of the shell, and the retractable wing assembly has a retracted state and an expanded state.

[0008] In the above technical solution, preferably, the front end of the underwater flow guide head is a flow guide circular arc structure, and the front end of the water surface flow guide head is a conical structure.

[0009] In the above technical solution, preferably, N type lines are arranged in a ring shape between the underwater flow guide head and the water surface flow guide head, and the type lines are gathered towards the water surface flow guide head.

[0010] In the above technical solution, preferably, the shell comprises a sealed shell located at the front and a water permeable shell located at the rear, the underwater flow guide head is arranged at the front end of the sealed shell, and the water surface flow guide head is arranged at the rear end of the water permeable shell.

[0011] In the above technical solution, preferably, the inside of the sealed shell is the water filling cavity, a pressure-resistant functional cabin is arranged inside the water filling cavity, and the attitude adjustment unit is arranged in the pressure-resistant functional cabin.

[0012] In the above technical solution, preferably, the water filling and discharging assembly is arranged inside the sealed shell, and the water filling and discharging assembly comprises a water filling unit and a water discharging unit; the water filling unit comprises a water filling pipeline and a water filling pump, the water inlet of the water filling pipeline is connected to the sealed shell and communicates with the outside, the water outlet of the water filling pipeline communicates with the inside of the sealed shell, and the water filling pump is connected in series to the water filling pipeline; the water discharging unit comprises a water discharging pipeline and a water discharging pump, the water outlet of the water discharging pipeline is connected to the sealed shell and communicates with the outside, the water inlet of the water discharging pipeline communicates with the inside of the sealed shell, and the water discharging pump is connected in series to the water discharging pipeline.

[0013] In the above technical solution, preferably, the inside of the sealed shell is provided with a propelling flow guide channel, the water inlet and outlet of the propelling flow guide channel are connected to the sealed shell, the water inlet of the propelling flow guide channel is arranged at the lower part of the sealed shell, the water outlet of the propelling flow guide channel is arranged at the end of the sealed shell close to the underwater flow guide head, and the active propeller is a water power driver installed in the propelling flow guide channel.

[0014] In the above technical solution, preferably, the folding wing assembly comprises a wing plate and a folding driver, the wing plate is installed on the sealed shell through a rotating shaft, and the folding driver drives the wing plate to flip around the rotating shaft and form a folding or unfolding posture.

[0015] In the above technical solution, preferably, a buoyancy adjusting unit is arranged, the buoyancy adjusting unit comprises an oil circuit assembly and an outer oil bag connected to the oil circuit assembly, the oil circuit assembly is installed in the pressure-resistant functional cabin, and the outer oil bag is arranged in the water-permeable shell.

[0016] The double-navigation-state unmanned vehicle has the following advantages and effects:

[0017] 1. Double-navigation-state seaworthiness: The unmanned vehicle has the capability of being seaworthy in both water surface and underwater navigation states, solves the limitations of single navigation state of existing water surface and underwater unmanned vehicles, and provides greater flexibility and application range. The diversified application scenarios make the unmanned vehicle suitable for different fields such as ocean survey, resource exploration and rescue operations.

[0018] 2. Fast response and long endurance: In the water surface navigation state, the vehicle can quickly respond to task requirements and is suitable for short-time fast navigation, while in the underwater navigation state, the attitude adjusting unit acts in the form of a glider, has high adjustment efficiency, and is suitable for long-time slow navigation and long-endurance tasks. Efficient energy consumption management makes the water surface fast navigation and underwater long endurance both effectively satisfied, and improves the task execution efficiency and endurance of the vehicle.

[0019] 3. Shape optimization and drag reduction: The vehicle adopts a "double-head" shape, uses the "sharp head" as the bow and the "blunt head" as the stern for navigation in the water surface stage, and reverses the design in the underwater stage, thereby reducing water resistance, improving navigation stability, and enhancing the ocean observation capability.

[0020] 4. Stable and reliable switching of the sailing state: a water filling and draining assembly is used to adjust the trim characteristics of the vehicle, and switching between the two sailing states is performed. In the surface sailing state, the water in the sealed housing is drained, and the vehicle's center of buoyancy is mainly determined by the shape of the sealed housing. In the underwater sailing state, the sealed housing is filled with water, and the vehicle's center of buoyancy is mainly determined by the shape of the pressure-resistant functional cabin and its relative position to the housing. The present application switches the center of buoyancy by filling and draining the housing, thereby adjusting the sailing state of the vehicle. The water filling and draining assembly is simple in structure, does not require complex electrically controlled valve groups and pipelines, and improves the reliability and stability of the vehicle, especially suitable for integration on unmanned platforms.

[0021] 5. Reducing operation and maintenance costs: the vehicle is equipped with retractable wings, reducing the space occupied by the vehicle's appendages. When the wings are not in use, they can be retracted to reduce drag and prevent accidental damage, increasing the durability and operational flexibility of the vehicle.

[0022] In summary, this dual-sailing unmanned vehicle overcomes the single sailing state problem of existing surface and underwater unmanned vehicles through innovative design and optimization, providing a more flexible, efficient and multifunctional ocean unmanned navigation platform. Its advantages include dual-sailing suitability, fast response and long endurance, shape optimization to reduce drag, simplified water filling and draining assembly, and retractable wing design, resulting in diverse application scenarios, efficient energy consumption management, reduced operation and maintenance costs, enhanced ocean observation capabilities, and improved task response speed.

[0023] The second object of the present application is to provide a sailing state switching method for a dual-sailing unmanned vehicle, comprising the following steps:

[0024] S1. Drain the water in the water filling cavity to make the unmanned vehicle float on the water surface;

[0025] S2. The retractable wing assembly of the unmanned vehicle is in a retracted position, the active propeller applies a water dynamic propulsion force to the unmanned vehicle, and the unmanned vehicle advances with the water surface flow guide head as the front end;

[0026] S3. Fill water into the water filling cavity to make the unmanned vehicle sink below the water surface;

[0027] S4. The retractable wing assembly of the unmanned vehicle is in an extended position, and the active propeller stops working;

[0028] S5. The attitude adjustment unit works and controls the unmanned vehicle to glide in the form of a glider underwater with the underwater flow guide head as the front end. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a structural schematic diagram of the unmanned vehicle described in the present application;

[0030] Figure 2 is Figure 1A view of the internal structure of the unmanned vehicle according to the present application;

[0031] Figure 3 is a schematic view of the internal structure of the unmanned vehicle according to the present application;

[0032] Figure 4 is a schematic view of the structure of the drainage unit according to the present application;

[0033] Figure 5 is a schematic view of the internal structure of the pressure-resistant cabin according to the present application;

[0034] Figure 6 is a schematic view of the internal structure of the unmanned vehicle in underwater navigation state according to the present application;

[0035] Figure 7 is a schematic view of the internal structure of the unmanned vehicle in surface navigation state according to the present application;

[0036] Figure 8 is a schematic view of the working of the navigation state switching of the unmanned vehicle according to the present application. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0038] In order to solve the problem that the current unmanned vehicle has single navigation state, poor adaptability, driving mode and weight adjustment performance, the present application provides a dual-navigation-state unmanned vehicle and a navigation state switching method. The dual-navigation-state vehicle has the advantages of adaptability, fast response, long endurance, and optimized shape to reduce resistance. In order to further illustrate the structure of the present application, the detailed description is as follows in combination with the drawings:

[0039] Please refer to Figure 1 and Figure 2 A dual-navigation-state unmanned vehicle, comprising a streamlined shell 1, and an attitude adjusting unit arranged inside the shell.

[0040] The main function of the shell is to protect the equipment inside the vehicle. The shell is made of high-strength, corrosion-resistant materials such as special alloy steel or composite materials. One end of the shell is the underwater flow guide head 1-1, and the other end is the water surface flow guide head 1-2. The front end of the underwater flow guide head is a flow guide arc structure, and the front end of the water surface flow guide head is a conical structure. The shell presents a water droplet shape design with one end as a circular arc blunt head and the other end as a sharp head. The water surface flow guide head serves as the front end of the underwater gliding movement of the vehicle. The arc structure of the end head plays a role in reducing drag and enhancing fluid dynamics during underwater navigation of the vehicle. When the underwater vehicle moves forward in water, water resistance will affect its movement, reducing its speed and energy efficiency. The design of the arc structure of the end head can reduce the resistance between the underwater vehicle and the water, improving the efficiency of underwater navigation. The underwater flow guide head serves as the front end of the vehicle's surface navigation. The sharp shell structure plays a role in reducing drag, improving stability, improving maneuverability, and reducing wave impact during the vehicle's surface navigation, enabling the vehicle to navigate more efficiently, stably, and safely on the water surface. In this embodiment, the shell includes a sealed shell at the front and a water-permeable shell at the rear. The underwater flow guide head is located at the front end of the sealed shell, and the water surface flow guide head is located at the rear end of the water-permeable shell. The rear of the sealed shell is internally sealed and mounted with a screw mounting rib ring and a rear end cover. The front end of the water-permeable shell is mounted to the rear rib ring of the sealed shell by screws, and the side wall of the water-permeable shell is provided with water-permeable holes.

[0041] N lines are arranged between the underwater flow guide head and the water surface flow guide head. The lines converge towards the water surface flow guide head. The lines are axial lines formed between two adjacent surfaces of the shell. The axial line structure plays a role in reducing water drag, improving navigation speed, improving stability, and reducing noise and vibration in the design of the underwater vehicle's surface. These optimized designs make the underwater vehicle more efficient and stable. The top of the "sharp" water surface flow guide head is equipped with a fixed rudder to improve the stability of underwater gliding movement. The communication positioning antenna of the vehicle is embedded in the inside.

[0042] Please refer to Figures 3-5 It also includes a water filling cavity 1-3, a water filling and draining assembly, a main propeller, a folding wing assembly 2, and a fixed rudder 3.

[0043] The water filling cavity is located inside the shell. In this embodiment, the inside of the sealed shell is the water filling cavity, and a pressure-resistant functional cabin 4 is arranged inside the water filling cavity. The attitude adjustment unit is arranged in the pressure-resistant functional cabin. The pressure-resistant functional cabin is fixedly installed in the sealed shell and is placed at the bottom of the inside of the sealed shell to reduce the height of the center of gravity of the vehicle. The outside of the pressure-resistant functional cabin is a pressure-resistant cabin shell, and the inside is installed with an electric control communication unit, an attitude adjustment unit 4-1, a buoyancy adjustment unit 4-2, etc. The electric control communication unit mainly includes a main control box, an iridium star module, and a wireless module.

[0044] The above pressure-resistant cabin is the prior art, wherein the attitude adjusting unit mainly comprises a pitch adjusting mechanism and a roll adjusting mechanism. The pitch adjusting mechanism mainly comprises a sliding guide rail, an energy storage battery, a motor controller, a pitch motor assembly, a motor base, a lead screw, a lead screw nut, a lead screw sleeve, etc. The pitch adjusting mechanism is driven by the pitch motor assembly to realize linear reciprocating movement of the energy storage battery along the axis direction of the vehicle on the sliding guide rail, change the position of the center of gravity of the vehicle in the axis direction, and realize pitch angle adjustment of the vehicle. The roll adjusting mechanism comprises a roll motor assembly, a driving pinion, a driven gear, an angle sensor gear, etc. When the driving pinion drives the driven gear to rotate, the energy storage battery rotates around the axis of the vehicle, and the roll angle adjustment of the unmanned vehicle is realized. The pitch adjusting mechanism and the roll adjusting mechanism jointly realize the attitude angle adjustment of the underwater gliding process of the vehicle, and further adjust the underwater gliding trajectory of the vehicle.

[0045] The buoyancy adjusting unit is used to drive the buoyancy of the high-pressure load in the kilometer water depth. The buoyancy adjusting unit comprises an oil circuit assembly and an outer oil bag connected with the oil circuit assembly. The oil circuit assembly is installed in the pressure-resistant cabin, and the outer oil bag is arranged in the water-permeable shell. The oil circuit assembly mainly comprises an oil discharge circuit and an oil return circuit. The oil discharge circuit is connected with the inner oil tank, the gear pump, the filter, the one-way valve, the front end cover and the outer oil bag 4-21 in sequence. The oil return circuit is connected with the outer oil bag, the front end cover, the electromagnetic valve and the inner oil tank in sequence. The outer oil bag is in contact with seawater, and the volume change of the outer oil bag can change the buoyancy of the vehicle. The rest of the devices of the buoyancy adjusting unit are arranged in the pressure-resistant cabin. The buoyancy adjusting unit uses the oil discharge circuit and the oil return circuit to adjust the oil volume of the outer oil bag, and further changes the buoyancy of the vehicle, so as to realize the diving or floating in the underwater gliding stage. The above attitude adjusting unit and buoyancy adjusting unit are the prior art in the current underwater glider. The setting of the attitude adjusting unit and the buoyancy adjusting unit enables the vehicle to move in the form of gliding underwater.

[0046] The water filling and draining assembly is used for filling water in the water filling cavity or draining water in the water filling cavity. In the embodiment, the water filling and draining assembly is arranged on the inner side of the sealed shell, and the water filling and draining assembly comprises a water filling unit 5 and a water draining unit 6. The water filling unit comprises a water filling pipeline and a water filling pump. The water inlet of the water filling pipeline is connected to the sealed shell and communicates with the outside. The water outlet of the water filling pipeline communicates with the inner side of the sealed shell. The water filling pump is connected in series to the water filling pipeline. The water draining unit comprises a water draining pipeline 6-1 and a water draining pump 6-2. The water outlet of the water draining pipeline is connected to the sealed shell and communicates with the outside. The water inlet of the water draining pipeline communicates with the inner side of the sealed shell. The water draining pump is connected in series to the water draining pipeline. The connection between the water filling pipeline and the sealed shell and the connection between the water draining pipeline and the sealed shell are sealed. The water inlet of the water filling pipeline and the water outlet of the water draining pipeline are arranged on the lower part of the sealed shell. The water filling pipeline and the water draining pipeline are further connected in series to a one-way valve 6-3. A water level probe 7 for detecting the water level is arranged in the inner part of the sealed shell. A plurality of vertically spaced water level probes are arranged in the inner part of the sealed shell through a probe fixing frame. The water filling unit and the water draining unit are used for adjusting the trim characteristics of the vehicle and switching the water surface navigation state and the underwater navigation state. The water filling unit and the water draining unit are used for adjusting the water amount in the water filling cavity, adjusting the waterline position of the vehicle on the water surface, and switching the “double-head double-navigation state” working mode.

[0047] The active propeller is arranged close to the underwater flow guide head. The active propeller is used for applying water dynamic propulsion force to the unmanned vehicle to point to the water surface flow guide head. In the embodiment, the inner part of the sealed shell is provided with a propelling flow guide channel 1-4. The water inlet and the water outlet of the propelling flow guide channel are connected to the sealed shell. The water inlet of the propelling flow guide channel is arranged on the lower part of the sealed shell. The water outlet of the propelling flow guide channel is arranged on the end part of the sealed shell close to the underwater flow guide head. The active propeller is a water dynamic driver 8 arranged in the propelling flow guide channel. Further, the flow guide channel is a circular tube. The two ends of the circular tube are sealingly connected to the sealed shell. Two flow guide channels are symmetrically arranged on the left and right of the end part of the sealed shell close to the underwater flow guide head. Water dynamic drivers are arranged in the two flow guide channels. The water dynamic drivers can be selected as paddle propellers. The active propeller comprises two propellers arranged on the “blunt head” end. The two propellers work together to provide power for the vehicle to quickly navigate on the water surface in the water surface navigation state. The rotation speeds of the two active propellers are adjusted to realize the thrust difference and change the direction of the water surface quick navigation.

[0048] The retractable wing assembly is installed on the side of the shell, and has a retracted and an expanded posture; the fixed rudder is fixed to the shell. The retractable wing assembly comprises a wing plate and a folding driver, the wing plate is installed on the sealed shell through a rotating shaft, and the folding driver drives the wing plate to rotate around the rotating shaft and form the retracted or expanded posture. In the fast sailing stage on the water surface, the folding driver drives the wing plate to rotate and realize the folding of the wing plate, and the wing plate is attached to the surface of the shell to reduce the air resistance of sailing. When the vehicle turns into the slow gliding stage under water, the folding driver expands the wing plate horizontally, and the wing plate is expanded horizontally to improve the lift-drag ratio of the vehicle sailing under water and convert more sailing driving force into driving component force in the direction of travel.

[0049] The switching mode of the dual navigation state unmanned vehicle in the embodiment is as shown in Figure 8

[0050] In the water surface stage, the vehicle sails with the "sharp end" as the bow and the "blunt end" as the stern. The two active propellers at the "blunt end" provide the stern driving force for the fast sailing of the unmanned vehicle on the water surface. In addition, by adjusting the relative rotating speed of the left and right active propellers, the heading of the vehicle is adjusted, as shown in Figure 7 .

[0051] In the underwater stage, the vehicle sails with the "blunt end" as the bow and the "sharp end" as the stern. The buoyancy adjusting unit works to realize oil discharge or oil return, changes the buoyancy of the vehicle, so that the vehicle is in a positive buoyancy or negative buoyancy state, and then drives the vehicle to ascend or descend. The center of mass adjusting unit adjusts the translation and rotation of the energy storage battery along the axis of the vehicle, and then changes the position of the center of gravity of the vehicle to adjust the pitch angle and roll angle, as shown in Figure 6 .

[0052] In the switching stage, the water filling pump of the water filling unit works to inject seawater into the water filling cavity, and the waterline of the vehicle gradually rises until the water filling cavity is filled with seawater, and the water level probe at the top of the water filling cavity feeds back a termination signal. The vehicle is switched from the water surface state to the underwater state. In another switching stage, the water pump of the water discharge unit works to discharge seawater from the sealed water tank, and the waterline of the vehicle gradually decreases until the water filling cavity is emptied, and the water level probe at the bottom of the water filling cavity feeds back a termination signal. The vehicle is switched from the underwater state to the water surface state.

[0053] At the same time, in the switching stage, the retractable wing assembly is expanded horizontally after entering the underwater state or is folded and attached to the surface of the shell in the water surface state.

[0054] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.​

Claims

1. A dual-mode unmanned aerial vehicle, comprising a streamlined hull, wherein an attitude adjustment unit is disposed inside the hull, characterized in that: One end of the shell is an underwater guide head, and the other end of the shell is an above-water guide head. The front end of the underwater guide head has a guide arc structure, and the front end of the above-water guide head has a conical structure. It also includes: A water-filling cavity is located inside the shell; A filling and draining assembly, which is used to fill the filling chamber with water or drain the water from the filling chamber; An active thruster is provided near the underwater guide head and is used to apply hydrodynamic propulsion to the unmanned vehicle in the direction of the surface guide head. A retractable side wing assembly is mounted on the side of the housing and has retracted and deployed postures.

2. The dual-mode unmanned aerial vehicle according to claim 1, characterized in that: The underwater guide head and the above-water guide head are provided with N circumferentially spaced lines, which converge toward the above-water guide head.

3. The dual-mode unmanned aerial vehicle according to claim 2, characterized in that: The housing includes a sealed housing at the front and a permeable housing at the rear. The underwater guide head is located at the front end of the sealed housing, and the above-water guide head is located at the rear end of the permeable housing.

4. The dual-mode unmanned aerial vehicle according to claim 3, characterized in that: The interior of the sealed housing is the water-filled cavity, and the water-filled cavity is equipped with a pressure-resistant functional chamber. The attitude adjustment unit is located in the pressure-resistant functional chamber.

5. The dual-mode unmanned aerial vehicle according to claim 4, characterized in that: The filling and draining assembly is located inside the sealed housing. The filling and draining assembly includes a filling unit and a draining unit. The filling unit includes a filling pipe and a filling pump. The inlet of the filling pipe is connected to the sealed housing and communicates with the outside. The outlet of the filling pipe is communicated with the inside of the sealed housing. The filling pump is connected in series with the filling pipe. The draining unit includes a draining pipe and a draining pump. The outlet of the draining pipe is connected to the sealed housing and communicates with the outside. The inlet of the draining pipe is communicated with the inside of the sealed housing. The draining pump is connected in series with the draining pipe.

6. The dual-mode unmanned aerial vehicle according to claim 4, characterized in that: The sealed housing has a propulsion guide channel inside. The inlet and outlet of the propulsion guide channel are connected to the sealed housing. The inlet of the propulsion guide channel is located at the lower part of the sealed housing, and the outlet of the propulsion guide channel is located at the end of the sealed housing near the underwater guide head. The active propulsion device is a hydrodynamic actuator installed in the propulsion guide channel.

7. The dual-mode unmanned aerial vehicle according to claim 4, characterized in that: The retractable side wing assembly includes a side wing plate and a folding driver. The side wing plate is mounted on the sealed housing via a pivot. The folding driver drives the side wing plate to rotate around the pivot and form a retractable or extended posture.

8. The dual-mode unmanned aerial vehicle according to claim 4, characterized in that: It includes a buoyancy adjustment unit, which includes an oil circuit assembly and an external oil bladder connected to the oil circuit assembly. The oil circuit assembly is installed in the pressure-resistant functional compartment, and the external oil bladder is disposed in the water-permeable shell.

9. A method for switching flight modes of a dual-flight unmanned aerial vehicle according to any one of claims 1-8, comprising the following steps: S1. Drain the water from the filling chamber until the unmanned vehicle floats on the water surface; S2. The retractable and extendable side wing assembly of the unmanned vehicle is in the retracted posture. The active thruster applies hydrodynamic propulsion to the unmanned vehicle, and the unmanned vehicle propels itself with the water-guided head as the leading edge. S3. Fill the water-filling cavity with water until the unmanned vehicle sinks below the water surface; S4. The unmanned aerial vehicle's retractable wing assembly is in the deployed position, and the active thrusters cease operation; S5. The attitude adjustment unit operates and controls the unmanned aerial vehicle to glide underwater in the form of a glider, with the underwater guide head as the leading edge.

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