Sliding dual-mode AUV (Autonomous Underwater Vehicle) and design method thereof

Abstract

The invention discloses a sliding dual-mode AUV (Autonomous Underwater Vehicle) and a design method thereof. The AUV comprises deformable hang gliders which are arranged on the two sides of a pressure-bearing shell and can be unfolded in a gliding mode to provide lift force and folded in a swimming mode to reduce fluid resistance; the buoyancy adjusting system comprises an outer oil bag, a front buoyancy adjusting oil tank, a rear buoyancy adjusting oil tank and a buoyancy adjusting power module and is used for dynamically adjusting the buoyancy and the gravity center position of the AUV through oil transfer; and the vector propulsion module is arranged at the tail part of the AUV, comprises a propeller of which the angle can be adjusted at two degrees of freedom and a guide plate matched with the propeller, and is used for providing direction control capability in a gliding mode. The AUV is provided with the tail vector propelling device, the two buoyancy adjusting oil tanks distributed on the front portion and the rear portion of the interior of the pressure-bearing shell and the deformable hang gliders located on the two sides of the AUV body at the same time, so that the AUV has the two operation modes of gliding depending on buoyancy and swimming depending on neutral buoyancy, and flexible switching can be achieved according to operation tasks.

Description

Technical Field

[0001] The present invention belongs to the technical field of autonomous underwater vehicles (AUVs), and relates to a gliding and swimming dual-mode AUV and its design method. Background Art

[0002] An autonomous underwater vehicle (AUV) is an unmanned autonomous device used for tasks such as ocean exploration, environmental monitoring, and marine resource exploration. Currently, AUVs are mainly divided into two categories: gliding AUVs and swimming AUVs.

[0003] Gliding AUVs mainly rely on buoyancy adjustment for gliding motion, and have the characteristics of low energy consumption and long range, but are limited in terms of maneuverability and speed, and can only move in a sawtooth shape up and down underwater; swimming AUVs use propellers for propulsion, with strong maneuverability, but high energy consumption and limited endurance. Therefore, developing a dual-mode AUV that combines the advantages of gliding and swimming modes has become the key in the current field.

[0004] Existing hybrid-driven AUVs have both gliding and swimming functions at the same time, but mostly use fixed gliding wings and a single buoyancy adjustment module, resulting in limited gliding efficiency and increased swimming resistance. At the same time, existing AUVs mostly rely on a tail rudder for direction adjustment, resulting in insufficient flexibility of the AUV. In addition, limited by the shape structure design, existing dual-mode AUVs have relatively large losses during mode conversion and low energy efficiency.

[0005] Therefore, how to design an AUV that can flexibly switch between gliding and swimming modes, has low gliding resistance, high swimming efficiency, and adjustable attitude is an urgent problem to be solved in the current technical field. Summary of the Invention

[0006] The object of the present invention is to provide a gliding and swimming dual-mode AUV that can flexibly switch between gliding and swimming modes, has high-efficiency hydrodynamic characteristics and flexible attitude control capabilities. At the same time, the present invention also provides a design method for the gliding and swimming dual-mode AUV to optimize its key parameters and improve the overall performance.

[0007] In the first aspect of the present invention, there is provided a gliding and swimming dual-mode AUV, comprising:

[0008] A pressure-bearing housing for providing a main structure and accommodating internal modules;

[0009] A deformable gliding wing disposed on both sides of the pressure-bearing housing, which can be deployed in gliding mode to provide lift and retracted in swimming mode to reduce fluid resistance;

[0010] The buoyancy adjustment system includes an outer oil bladder, front and rear buoyancy adjustment fuel tanks, and a buoyancy adjustment power module, which is used to dynamically adjust the buoyancy and the position of the center of gravity of the AUV by transferring oil, so as to adapt to the switching between the gliding mode and the swimming mode;

[0011] The vector propulsion module is arranged at the tail of the AUV and includes a thruster that can adjust the angle in two degrees of freedom and a guide plate that cooperates with it, which is used to provide direction control ability in the gliding mode and enhance the flexibility of the propulsion system in the swimming mode;

[0012] The main control module is used to realize the mode switching, buoyancy adjustment, attitude control and propulsion system adjustment of the AUV according to the preset tasks and sensor data.

[0013] The deformable gliding wing is driven by a motor to perform unfolding and folding operations. The buoyancy adjustment power module provides power for the change of the oil volume through a hydraulic system. The angle adjustment of the thruster of the vector propulsion module is realized by a deep-sea servo.

[0014] In the second aspect of the present invention, a design method for a gliding and swimming dual-mode AUV is provided, including the following steps:

[0015] Step 1: Establish a three-dimensional model of the AUV, and calculate the position of the center of buoyancy of the AUV based on this model;

[0016] Step 2: Use the computational fluid dynamics method to optimize the position, aspect ratio and sweep angle of the gliding wing through the traversal method to obtain the best lift-to-drag ratio;

[0017] Step 3: Conduct a force analysis on the AUV, establish the force balance and moment balance relationships, and solve the relationships between the angle of attack and the gliding angle and between the speed and the gliding angle;

[0018] Step 4: Set and analyze different capacity states of the front and rear buoyancy adjustment fuel tanks, calculate the gliding time and energy consumption in combination with the gliding depth and gliding speed, and determine the optimal fuel tank capacity distribution and buoyancy gliding state.

[0019] In the design method, the optimization of the shape and position of the gliding wing is based on the principle of maximizing the lift-to-drag ratio, and the optimization of the fuel tank capacity distribution is based on the principles of minimizing energy consumption and maximizing the navigation speed.

[0020] Compared with the existing inventions, the present invention has the following beneficial effects:

[0021] (1) The present invention has a tail vector propulsion device, two sets of buoyancy adjustment fuel tanks distributed at the front and rear positions inside the pressure hull, and deformable gliding wings on both sides of the AUV body, enabling the AUV to have two operation modes of gliding relying on buoyancy and swimming in neutral buoyancy, and can be flexibly switched according to the operation tasks.

[0022] (2) The present invention adopts a deformable gliding wing design, enabling the gliding wing to unfold in the gliding mode to increase lift and gliding efficiency; in the swimming mode, the gliding wing folds up to reduce fluid resistance and improve propulsion efficiency, achieving efficient switching between the gliding and swimming modes.

[0023] (3) Through the design of front and rear independent buoyancy adjustment fuel tanks, dynamic adjustment of the AUV's center of gravity is achieved, making the gliding angle, gliding speed, and attitude control more precise, and improving navigation efficiency and stability.

[0024] (4) A vector propulsion module is used to replace the traditional tail rudder. The thruster has two degrees of freedom for adjustable angle, and is equipped with a guiding plate that can swing accordingly, enabling the AUV to accurately adjust its course in the gliding mode, improving the direction control ability, and reducing the energy loss caused by traditional tail rudder control.

[0025] (5) The energy loss during the conversion between the gliding and swimming modes of traditional AUVs is relatively large. The present invention optimizes the gliding wing shape and buoyancy adjustment strategy to make the mode switching smoother, reduce energy loss, and improve operation efficiency and endurance. Brief Description of the Drawings

[0026] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2(a) is a general schematic diagram of the folding and unfolding part of the gliding wing of the present invention;

[0028] Figure 2(b) is a schematic diagram of the actuator of the folding and unfolding part of the gliding wing of the present invention;

[0029] Figure 2(c) is a sectional view of the actuator of the folding and unfolding part of the gliding wing of the present invention;

[0030] Figure 3(a) is a schematic diagram of the external structure of the vector propulsion module of the present invention;

[0031] Figure 3(b) is a schematic diagram of the internal structure of the vector propulsion module of the present invention;

[0032] Figure 4(a) is a schematic diagram of the optimization of the position and shape of the gliding wing of the present invention;

[0033] Figure 4(b) is a flow chart of establishing the AUV dynamics model using the computational fluid dynamics method of the present invention;

[0034] Figure 4(c) is a schematic diagram of predicting the relationship between the angle of attack and the gliding angle of the AUV of the present invention;

[0035] Figure 4(d) is a schematic diagram of predicting the relationship between the speed and the gliding angle of the AUV of the present invention. Detailed Embodiments

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] This application provides a gliding and swimming dual-mode AUV, which includes a pressure-bearing shell, deformable gliding wings, an external oil bladder, front and rear buoyancy adjustment fuel tanks, a buoyancy adjustment power module, a vector propulsion module, a main control module, an underwater positioning module, a surface communication module, and a battery module.

[0038] The pressure-bearing shell is the main structure of the AUV, made of lightweight and high-strength materials, capable of withstanding the high pressure of the deep-sea environment, while providing internal space to accommodate the main control module, battery, and other electronic devices, and optimizing the internal layout to improve the stability and heat dissipation performance of the device.

[0039] The deformable gliding wings are arranged on both sides of the external shell of the AUV, unfolding in the gliding mode to provide greater lift and improve gliding efficiency; folding in the swimming mode to reduce fluid resistance and improve propulsion efficiency. The unfolding and folding of the gliding wings are driven by motors and intelligently controlled by the main control module to ensure the best gliding and swimming effects and optimize energy consumption.

[0040] The external oil bladder is installed in the wet cabin of the AUV, at the very front of the external shell, and can adjust the overall buoyancy of the AUV by increasing or decreasing the internal oil, realizing the switching between the gliding state and the swimming state to adapt to different underwater mission requirements.

[0041] The front and rear buoyancy adjustment fuel tanks are respectively located at the bow and stern of the AUV. By controlling the change in the volume of the oil in the fuel tanks, the dynamic adjustment of the center of gravity of the AUV is realized, thereby optimizing the gliding angle and speed, improving the navigation stability, and at the same time providing more precise attitude control ability to adapt to the gliding requirements under different environmental conditions.

[0042] The buoyancy adjustment power module, including a hydraulic system, etc., is used to provide the power required for the change in oil volume.

[0043] The vector propulsion module is arranged at the tail of the AUV and includes a set of vector propulsion devices that can adjust the angle of the thruster in two degrees of freedom. A guiding plate that can swing accordingly is provided outside the propulsion module. This guiding plate can replace the traditional tail rudder, improve the direction control ability of the AUV in the gliding mode, and at the same time enhance the flexibility of the propulsion system in the swimming mode, enabling the AUV to adapt to complex water flow environments.

[0044] The main control module is used for the overall control of the AUV, and is responsible for realizing mode switching, buoyancy adjustment, attitude control, propulsion system adjustment and underwater positioning functions. The main control module combines multi-sensor data to achieve adaptive navigation and optimize energy management, so as to improve the endurance and autonomous operation ability of the AUV.

[0045] The underwater positioning module, including an inertial navigation system, sonar, etc., is used to accurately locate the position and attitude of the vehicle.

[0046] The surface communication module is used to transmit data with an external control system when the AUV floats to the water surface, realizing remote monitoring and control. At the same time, it supports the upload of mission data and the download of remote instructions to optimize the underwater operation process.

[0047] The battery module provides the electric energy required during the operation of the AUV and has functions such as circuit protection.

[0048] Embodiment 1. A gliding and swimming dual-mode AUV

[0049] A gliding and swimming dual-mode AUV provided in this embodiment adopts a torpedo-shaped pressure-bearing shell, and its internal structure is as Figure 1 shown. Deformable gliding wings 4 are arranged on both sides of the shell, an external oil bladder 1 is arranged at the most bow part, a battery module 3 is arranged at the bow part, inner fuel tanks are respectively arranged at the bow section and the tail section, which are the front buoyancy adjustment fuel tank 2 and the rear buoyancy adjustment fuel tank 7 respectively, a buoyancy adjustment power module 10, a main control module 5 and an underwater positioning module 6 are arranged in the middle part, a surface communication module 8 is arranged at the tail part, a vector propulsion module 9 is arranged at the most tail part, and a guide plate is installed on the vector propulsion model.

[0050] The torpedo-shaped pressure-bearing shell is made of high-strength lightweight materials to ensure pressure resistance and corrosion resistance, and provide structural support for internal modules.

[0051] The deformable gliding wing, as shown in Figures 2(b) and 2(c), is jointly fixed by a sealed bearing seat 11, an upper fixed rotating shaft 12, a sealing ring 13, a retaining ring 14, and a lower sealing plug 15 (with the same diameter as the upper fixed rotating shaft, pressure balance). When the deformation mechanism operates, the reduction motor 16 drives the turbine 17 and the worm 18 to rotate, and then drives the upper fixed rotating shaft to rotate, so that the gliding wing is retracted (as shown in Figure 2(a)) or unfolded (as shown in Figure 2(b)).

[0052] The external oil bladder is located in the wet cabin of the AUV, and has an oil exchange with the inner fuel tank, thereby adjusting the buoyancy of the AUV.

[0053] The battery module is fixed to the bow of the AUV with bolts to supply power to each module and optimize power management to extend the endurance.

[0054] The inner fuel tank (front and rear) cooperates with the buoyancy adjustment power module as part of the buoyancy adjustment system to change the center of gravity position of the AUV by adjusting the volume of oil in the front and rear, so as to realize the adjustment of the gliding angle and gliding speed.

[0055] The buoyancy adjustment power module is connected to the front and rear fuel tanks and the outer oil bladder through hydraulic pipelines to realize the exchange of oil inside the AUV, so as to accurately adjust the buoyancy and center of gravity position of the AUV, and improve the gliding performance and attitude control ability.

[0056] The external part of the surface communication module is wrapped with a fairing, and the communication antenna is connected to the internal main control module, which can reduce the navigation resistance while realizing communication with the outside world.

[0057] The vector propulsion module, such as Figure 3(a) 、 3(b) shown, the output shaft of the deep-sea servo 9-1 is connected to the respective swivel frames (horizontal swivel frame 9-2 or vertical swivel frame 9-3) through bolts. The swivel frame and the stern shell 9-6 are connected by a rotating shaft 9-4, and the tail of the deep-sea thruster 9-5 is connected to the swivel frame by bolts.

[0058] Guide plates 9-8 are arranged on the thruster shroud 9-7. At this time, when the deep-sea servo is started, it can push the swivel frame to rotate around the rotating shaft, and then drive the thruster to rotate, so as to realize the adjustment of two degrees of freedom of the thruster. In addition, the guide plates on the thruster shroud will rotate with the thruster to realize the precise direction control of the gliding mode.

[0059] The AUV in this embodiment can flexibly switch between two working modes, namely the buoyancy gliding mode and the neutral buoyancy swimming mode, to meet different operation requirements. The specific implementation is as follows:

[0060] (1) Buoyancy gliding mode

[0061] The buoyancy gliding mode is divided into ascending gliding and descending gliding. Before entering the gliding mode, the deformable gliding wing unfolds to increase the lift-drag ratio and reduce the energy consumption during the ascending or descending process.

[0062] During descending gliding, the buoyancy adjustment power module fills the front and rear inner fuel tanks with oil from the outer oil bladder. At this time, the overall gravity of the AUV is greater than the buoyancy, and it starts to dive. At the same time, the main control module adjusts the oil ratio between the two inner fuel tanks according to the AUV attitude requirements, so that the oil in the front fuel tank increases, and the oil in the rear fuel tank decreases or remains unchanged. At this time, the center of gravity of the AUV moves forward, the bow deflects downward, and it starts to glide downward at a certain angle.

[0063] During buoyant gliding, the buoyancy adjustment power module drains the oil from the two inner fuel tanks into the outer oil bladder. At this time, the overall buoyancy of the AUV is greater than the gravity, and it begins to rise. At the same time, the main control module adjusts the oil proportion between the two inner fuel tanks according to the AUV attitude requirements, reducing the oil in the front fuel tank and increasing or keeping the oil in the rear fuel tank unchanged. At this time, the center of gravity of the AUV moves backward, and the bow deflects upward, starting to glide upward at a certain angle. Thus, precise control of the gliding angle can be achieved.

[0064] In addition, the guide plate of the vector propulsion system is dynamically adjusted according to the gliding direction to optimize the gliding path and maintain stability.

[0065] (2)Neutral buoyancy swimming mode

[0066] Before entering the swimming state, the deformable gliding wing is retracted to reduce fluid resistance and improve propulsion efficiency. At this time, the buoyancy adjustment power module adjusts the overall buoyancy of the AUV to neutral according to the instructions of the main control module. The vector propulsion system is started, and by adjusting the angle of the thruster, efficient swimming of the AUV is achieved. Thus, highly maneuverable swimming of the AUV can be realized to adapt to complex water flow environments.

[0067] (3)Mode switching

[0068] The AUV can seamlessly switch between the buoyant gliding mode and the neutral buoyancy swimming mode according to mission requirements.

[0069] When switching from the gliding mode to the swimming mode, the main control module adjusts the buoyancy adjustment system to make the buoyancy of the AUV close to neutral, retracts the gliding wing, and then starts the thruster to enter the swimming mode.

[0070] When switching from the swimming mode to the gliding mode, the main control module turns off the thruster, deploys the gliding wing, and adjusts the buoyancy adjustment system to make the AUV enter the gliding state.

[0071] Embodiment 2. A design method for a gliding and swimming dual-mode AUV

[0072] The design method of this embodiment mainly improves the gliding performance and energy utilization efficiency of the AUV by optimizing the shape and position of the gliding wing and simultaneously optimizing the fuel tank capacity.

[0073] Step 1: Establish a three-dimensional model of the AUV and calculate the position of the center of buoyancy based on this model. Use the traversal method to set different wing position parameters before and after this center of buoyancy position, and use the computational fluid dynamics method to numerically calculate the lift-to-drag ratio of the wing in different position cases.

[0074] Take the wing position with the maximum lift-to-drag ratio as a fixed value, use the traversal method to set different aspect ratios at this position, and use the computational fluid dynamics method to numerically calculate the lift-to-drag ratio of the wing in different aspect ratio cases.

[0075] Again, taking the aspect ratio with the maximum lift-to-drag ratio as a fixed value, the traversal method is used to set different wing sweep angles under this aspect ratio condition, and the computational fluid dynamics method is used to numerically calculate the lift-to-drag ratio of the wing under different sweep angles. Thus, as shown in Figure 4(a), the optimal wing shape and position parameters can be obtained.

[0076] Step 2: Analyze the forces acting on the AUV. The following equations can be obtained through the force balance in the horizontal direction, the force balance in the vertical direction, and the moment balance relationship:

[0077]

[0078] B

[0079]

[0080] Among them, is the angle of attack, is the glide angle, is the lift force, is the drag force, M is the pitching moment, B is the buoyancy force, 、 are the longitudinal velocity and the vertical velocity, 、 are the added masses, is the difference in the weights of the front and rear fuel tanks, is the position of the front fuel tank from the center of buoyancy, is the position of the rear fuel tank from the center of buoyancy.

[0081] Furthermore, the lift force, the drag force, and the pitching moment can be calculated by the following equations:

[0082] where V is the 、 resultant velocity composed of, 、 、 、 、 、 are all hydrodynamic coefficients, which can be obtained by hydrodynamic simulation calculation. The specific flow chart is shown in Figure 4(b).

[0083] Furthermore, in Figure 4(b), after obtaining the three-dimensional model, the three-dimensional model is meshed, then the simulation parameters are set, a series of glide angles are selected for oblique navigation simulation, and finally the least squares method is used to solve the simulation results, so as to obtain the above-mentioned hydrodynamic coefficients.

[0084] Solving the above equations can obtain the following equations:

[0085]

[0086] Among them, is the glide angle. Under the condition that the above formula has a solution, the range of the glide angle can be obtained as follows:

[0087]

[0088] Taking any value within the above range, the formulas for calculating the angle of attack and speed can be obtained as follows:

[0089]

[0090]

[0091] Among them is the net buoyancy. Thus, the relationship between the angle of attack and the glide angle and the relationship between the speed and the glide angle can be obtained as shown in Figure 4(c) and 4(d) . For these two relationship diagrams, increasing the fuel quantity in the inner fuel tank, that is, increasing the net buoyancy, will cause the vertical speed to increase. At this time, the horizontal speed first increases and then decreases. Thus, the attitude angle of the optimal horizontal speed can be obtained.

[0092] Step 3: Set different capacity states of the front and rear fuel tanks and arrange and combine different situations. Then substitute them into the relationship diagram established in Step 2 to calculate the horizontal navigation speed and vertical navigation speed in this fuel tank capacity state.

[0093] According to the preset glide depth and the glide speed obtained by calculation, the required glide time can be obtained. Then, combined with the power consumption of the buoyancy adjustment power module, the energy consumption in the glide mode can be calculated. Finally, by comparing different energy consumption situations and navigation speeds, the optimal distribution of the front and rear inner fuel tank capacities and the optimal buoyancy glide state can be obtained.

[0094] As described above, the present invention can be preferably implemented. The above embodiments are only preferred embodiments of the present invention and are not used to limit the implementation scope of the present invention; that is, all equivalent changes and modifications made according to the content of the present invention are covered by the scope required to be protected by the claims of the present invention.

Claims

1. A gliding dual-mode AUV, characterized in that: include: A pressure-bearing shell, used to provide a main structure and accommodate internal modules; Deformable gliders are arranged on both sides of the pressure-bearing shell, and can be deployed in gliding mode to provide lift, and folded in swimming mode to reduce fluid resistance; The buoyancy adjustment system includes an external oil bag, front and rear buoyancy adjustment oil tanks, and a buoyancy adjustment power module, which is used to dynamically adjust the buoyancy and center of gravity of the AUV through the transfer of oil to adapt to the switching between gliding mode and swimming mode; The vector propulsion module is installed at the tail of the AUV and includes a thruster with two degrees of freedom and a guide plate that matches it. It is used to provide directional control in gliding mode and enhance the flexibility of the propulsion system in swimming mode. The main control module is used to realize the AUV's mode switching, buoyancy adjustment, attitude control, and propulsion system adjustment according to the preset mission and sensor data; The deformable glider is driven by a motor to unfold and fold, the buoyancy adjustment power module provides power for oil volume changes through a hydraulic system, and the propeller angle adjustment of the vector propulsion module is achieved by a deep-sea steering gear.

2. The gliding dual-mode AUV according to claim 1, characterized in that: The unfolding and folding of the deformable glider is realized by a turbine worm mechanism driven by a motor. The glider is fixed by a sealed bearing seat, an upper fixed shaft, a sealing ring, a retaining ring and a lower sealing plug to ensure its reliability and durability in an underwater environment.

3. The gliding dual-mode AUV according to claim 1, characterized in that: The guide plate can be adjusted synchronously according to the angle change of the thruster to improve the direction control ability of the AUV in the gliding mode and the flexibility in the swimming mode.

4. The gliding dual-mode AUV according to claim 1, characterized in that: The pressure hull is made of high-strength lightweight material and is torpedo-shaped to optimize fluid dynamics performance, reduce navigation resistance, and provide structural support and protection for internal modules.

5. A design method for a gliding dual-mode AUV, characterized in that: The following steps are involved: Step 1: Establish a three-dimensional model of the AUV, and calculate the buoyancy center of the AUV based on the model; Step 2: Using computational fluid dynamics methods, the position, aspect ratio and sweep angle of the glider are optimized by ergodic method to obtain the best lift-to-drag ratio; Step 3: Perform force analysis on the AUV, establish force balance and torque balance, and solve the relationship between the attack angle and the glide angle, as well as the relationship between the speed and the glide angle; Step 4: Set and analyze different capacity states of the front and rear buoyancy adjustment tanks, calculate the gliding time and energy consumption in combination with the gliding depth and gliding speed, and determine the optimal tank capacity allocation and buoyancy gliding state; In the design method, the shape and position of the glider are optimized based on the principle of maximizing the lift-to-drag ratio, and the fuel tank capacity distribution is optimized based on the principles of minimizing energy consumption and maximizing the navigation speed.

6. The design method of the gliding dual-mode AUV according to claim 5, characterized in that: In step 2, lift-to-drag ratios at different positions, aspect ratios and sweep angles are calculated by computational fluid dynamics simulation, and a parameter combination with the maximum lift-to-drag ratio is selected as the final design parameters of the glider.

7. The design method of the gliding dual-mode AUV according to claim 5 or 6, characterized in that: In step 3, a mathematical model is established through the horizontal force balance, vertical force balance and moment balance relationship, and the relationship between the angle of attack and the glide angle, and the relationship between the speed and the glide angle are solved by combining the hydrodynamic coefficients obtained by fluid mechanics simulation.

8. The design method of the gliding dual-mode AUV according to claim 7, characterized in that: In step 4, by comparing the energy consumption and navigation speed under different fuel tank capacity states, a fuel tank capacity allocation scheme with the minimum energy consumption and the maximum horizontal speed is selected to improve the gliding efficiency and endurance of the AUV.

9. The design method of the gliding dual-mode AUV according to claim 6, characterized in that: The step 2 also includes meshing the three-dimensional model of the AUV and setting simulation parameters, and fitting the simulation results using the least squares method to obtain accurate hydrodynamic coefficients.

10. The design method of the gliding dual-mode AUV according to claim 8, characterized in that: The design method also includes a comprehensive evaluation of the AUV's gliding depth, gliding time, and energy consumption to determine the optimal buoyancy gliding state to ensure the AUV's efficient operation under different mission requirements.

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