Underwater vehicle buoyancy adjustment device and method

Abstract

The present invention discloses a buoyancy adjustment device for an underwater vehicle. The lower end of the outer wall of the main piston of the main buoyancy adjustment unit is mounted on a base, and the upper end is connected to the main inner piston through a main bellows. A servo push rod motor is mounted on the base, the lower end of the push rod is connected to the servo push rod motor, and the upper end is connected to the main inner piston. The servo push rod motor controls the push rod to extend and retract, driving the main inner piston to move relative to the outer wall of the main piston to adjust the volume of the main piston device. A main oil bladder is mounted between the servo push rod motor and the main inner piston, and oil is injected into the main oil bladder to assist the movement of the main inner piston. The right buoyancy adjustment unit and the left buoyancy adjustment unit are symmetrically arranged on both sides of the main buoyancy adjustment unit. Oil is injected into the side oil bladders to push the side inner pistons to adjust the piston volume. The present invention can use the push rod to quickly and accurately adjust the buoyancy in shallow water environments. When entering deep water environments, the buoyancy can be changed to the oil bladder-assisted push rod mode, further expanding its scope of use.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater vehicles, and in particular to a buoyancy regulating device and method for underwater vehicles. Background Art

[0002] Existing underwater vehicles conducting deep-sea operations typically require buoyancy adjustment devices, which can be categorized as either adjustable ballast or variable volume. Adjustable ballast systems achieve this by either discarding ballast blocks or by absorbing or discharging seawater. The former is generally suitable for deep-sea exploration, where the vehicle's motion is difficult to change during descent and ascent. The latter is typically used on large military installations such as submarines, but is generally difficult to apply to small AUVs and ROVs due to device size and power limitations. Variable volume buoyancy adjustment systems primarily adjust their buoyancy by changing their volume. Typically, a deformable container, such as a bladder, is attached to the buoyancy adjustment system, which is inflated with air or oil to adjust its volume. Flow rate calculations allow for a relatively accurate calculation of the amount of air or oil added, and while this type of buoyancy adjustment system has some application in small underwater equipment, it also suffers from the drawbacks of complex device integration and high cost. Furthermore, in shallow water environments (less than 20 meters deep), buoyancy adjustment efficiency is low due to the influence of surface waves and currents, making it difficult to meet the demanding control requirements of hovering, positioning, and tracking control in shallow water. Summary of the Invention

[0003] The main purpose of the present invention is to provide a buoyancy adjustment device for underwater vehicles. The device is a variable volume buoyancy adjustment device that uses an electric push rod and an oil bag. It is particularly suitable for installation on underwater vehicles with shallow water depths such as lakes and reservoirs and nearshore areas. It can use the electric push rod to quickly and accurately adjust the buoyancy in shallow water environments. When entering deep water environments, it can switch to the oil bag assisted push rod mode to change the buoyancy, further expanding its scope of use and providing new design ideas for the design and development of existing underwater vehicles.

[0004] The technical solution adopted in the present invention is:

[0005] A buoyancy adjustment device for an underwater vehicle, comprising a main buoyancy adjustment unit, a right buoyancy adjustment unit and a left buoyancy adjustment unit; the main buoyancy adjustment unit comprises a base, a main piston device, a push rod device and a main oil bag; the main piston device comprises a main piston outer wall, a main inner piston and a main bellows, the lower end of the main piston outer wall is mounted on the base, and the upper end is connected to the main inner piston through the main bellows; the push rod device comprises a servo push rod motor and a push rod, the servo push rod motor is mounted on the base and is located inside the main piston outer wall, the lower end of the push rod is connected to the servo push rod motor, and the upper end is connected to the main inner piston, the push rod is controlled to retract and retract by the servo push rod motor, thereby driving the main inner piston to move relative to the main piston outer wall, so as to Adjust the volume of the main piston device; the main oil bag is installed between the servo push rod motor and the main inner piston, and a hole for the push rod to pass through is provided in the middle of the main oil bag, and the main inner piston is assisted to move by injecting oil into the main oil bag; the right buoyancy adjustment unit and the left buoyancy adjustment unit are symmetrically arranged on both sides of the main buoyancy adjustment unit, and have the same structure, both including a side piston outer wall, a side inner piston, a side bellows and a side oil bag, the side piston outer wall and the side inner piston are connected by a side bellows, and the side oil bag is arranged between the inner end of the side piston outer wall and the side inner piston, and the side inner piston is pushed to move by injecting oil into the side oil bag to adjust the piston volume.

[0006] In the above scheme, the buoyancy adjustment device also includes a floating state adjustment unit, which includes a central cavity, a transverse driving device, a cross bar and an electromagnet; the central cavity is installed under the base, and the outer walls of the side pistons of the right buoyancy adjustment unit and the left buoyancy adjustment unit are symmetrically installed on the left and right sides of the central cavity; the cross bar transversely passes through the central cavity and the right buoyancy adjustment unit and the left buoyancy adjustment unit; the two electromagnets are respectively installed at the left and right ends of the cross bar, and when powered on, the two electromagnets are respectively adsorbed on the outer end walls of the left and right side inner pistons; the transverse driving device is used to drive the cross bar to move left and right, thereby realizing floating state adjustment.

[0007] In the above scheme, the central cavity, the side oil bag, and the central part of the side inner piston are all provided with through holes for the cross rod to pass through. The cross rod passes through the central cavity, the side oil bag, and the inner end wall of the side inner piston in sequence, and the cross rod is perpendicular to the push rod.

[0008] In the above scheme, the transverse movement drive device includes a servo motor and a reduction gearbox. The reduction gearbox is provided with a worm output shaft, and the cross bar is provided with a rack adapted to the worm output shaft. The servo motor drives the worm output shaft to rotate, thereby driving the cross bar to move left and right.

[0009] In the above solution, a guide rail is fixedly mounted on the crossbar, a guide rail slider is fixedly mounted on the central cavity, the guide rail and the guide rail slider are slidably matched, and a displacement sensor is provided on the guide rail slider to detect the sliding distance of the crossbar.

[0010] In the above solution, limit baffles are provided at both ends of the guide rail to limit the displacement of the cross bar and prevent the lateral inner piston from separating from the lateral piston outer wall.

[0011] In the above solution, a depth gauge is also installed on the buoyancy regulating device.

[0012] In the above scheme, the buoyancy regulating device also includes an oil storage tank, in which an oil pump is provided. One end of the oil pump is provided with an oil inlet and an oil outlet for connecting to an external oil tank; the other end of the oil pump is provided with three oil pipe openings, the main oil bag is connected to one oil pipe opening through the main oil bag oil pipe, and the side oil bags on the left and right sides are respectively connected to the other two oil pipe openings through the side oil bag oil pipes.

[0013] Correspondingly, the present invention also proposes a method for adjusting the buoyancy of an underwater vehicle, which adopts the above-mentioned buoyancy adjusting device. When working in shallow water, the volume of the main piston device is changed by the push rod to drive the main bellows to expand and contract, thereby adjusting the buoyancy; when working in deep water, due to the increase in water pressure, the working environment of the electric push rod is not good, and the robot is controlled to float by injecting oil into the main oil bag to assist the extension of the push rod; in the emergency floating state, the side inner piston is pushed open by injecting oil into the side oil bags on both sides to provide additional buoyancy, or the main oil bag is injected with oil at the same time to assist the push rod to extend quickly, thereby achieving rapid floating.

[0014] In the above method, the suspension posture of the underwater vehicle is adjusted by the buoyancy adjustment unit. When the underwater vehicle needs to tilt to the left underwater, the servo motor drives the worm output shaft to translate to the right, so that the piston volume of the left buoyancy adjustment unit decreases and the piston volume of the right buoyancy adjustment unit increases, thereby causing the center of buoyancy to shift to the right, the device is higher on the right and lower on the left, and the left-tilt buoyancy adjustment is completed; when the underwater vehicle needs to tilt to the right underwater, the servo motor drives the worm output shaft to translate to the left.

[0015] The beneficial effects produced by the present invention are:

[0016] 1. The buoyancy control device of this invention is suitable for both shallow and deep water operations. For shallow water, the volume of the main piston assembly is adjusted by a built-in electric push rod, enabling rapid buoyancy adjustment, making it suitable for shallow water operations. In deep water, due to increased water pressure, the electric push rod performs poorly, requiring a deep water mode. Oil is injected into the main oil bladder to assist in extending the push rod, controlling the robot's ascent. Therefore, the device can automatically switch operating modes for different navigation depths, extending the underwater vehicle's operating range. Furthermore, the oil bladder and electric push rod mode can be used for more precise control of buoyancy parameters.

[0017] 2. The present invention can provide additional buoyancy for the device through the left and right side buoyancy adjustment units to achieve rapid floating in an emergency; at the same time, the integrated design of the left and right side buoyancy adjustment units and the floating state adjustment unit can flexibly change the floating state of the robot without changing the size of the buoyancy.

[0018] 3. The main buoyancy adjustment unit of the present invention adjusts the volume of the main piston device by driving the piston to extend and retract through an electric push rod. Compared with the traditional method of changing the volume by inflating the airbag or filling it with oil, the buoyancy adjustment speed is fast and the accuracy is high, which is conducive to the rapid stabilization of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a schematic diagram of the overall structure of the underwater vehicle buoyancy regulating device of the present invention;

[0021] Figure 2 It is a structural schematic diagram of the main buoyancy regulating unit of the underwater vehicle buoyancy regulating device of the present invention;

[0022] Figure 3 yes Figure 2 Schematic diagram of the internal structure of the main buoyancy adjustment unit;

[0023] Figure 4 2. It is a structural schematic diagram of the right buoyancy adjustment unit of the underwater vehicle buoyancy adjustment device of the present invention;

[0024] Figure 5 This is a structural cross-sectional view of the right buoyancy adjustment unit of the underwater vehicle buoyancy adjustment device of the present invention;

[0025] Figure 62. It is a structural schematic diagram of a buoyancy regulating unit of an underwater vehicle buoyancy regulating device according to the present invention;

[0026] Figure 7 2. It is a schematic structural diagram of a lateral movement drive device of an underwater vehicle buoyancy regulating device according to the present invention;

[0027] Figure 8 It is a structural schematic diagram of the oil storage tank of the underwater vehicle buoyancy regulating device of the present invention.

[0028] In the figure: 10, main buoyancy adjustment unit; 101, base; 102, outer wall of main piston; 103, main inner piston; 104, main bellows; 105, servo push rod motor; 106, push rod; 107, top cover; 108, oil bladder base; 109, main oil bladder; 110, main oil bladder oil pipe;

[0029] 20. Right buoyancy adjustment unit; 201. Side piston outer wall; 202. Side inner piston; 203. Side bellows; 204. Side oil bladder; 205. Side oil bladder oil pipe;

[0030] 30. Left buoyancy adjustment unit;

[0031] 40. Floating adjustment unit; 401. Central cavity; 402. Servo motor; 403. Reducer; 404. Crossbar; 405. Electromagnet; 406. Rack; 407. Guide rail; 408. Guide rail slider; 409. Displacement sensor; 410. Worm; 411. Depth gauge;

[0032] 50. Oil storage tank; 51. Oil pump. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] It should be noted that the illustrations provided in the embodiments of the present invention are only schematic illustrations of the basic concept of the present invention. Therefore, the drawings only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0035] In the present invention, it should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like are used to indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate the description of the present application and to simplify the description. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present application. Furthermore, the terms "first" and "second" are used solely for descriptive and distinguishing purposes and should not be construed as indicating or implying relative importance.

[0036] like Figure 1 The figure shows an underwater vehicle buoyancy adjustment device according to an embodiment of the present invention. Installed between the pressure-resistant cabin and the non-watertight hull of an underwater vehicle, it is used to adjust the buoyancy and suspension state of the underwater vehicle. The buoyancy adjustment device includes a main buoyancy adjustment unit 10, a right buoyancy adjustment unit 20, a left buoyancy adjustment unit 30, a floating state adjustment unit 40, and an oil tank 50.

[0037] like Figure 2 As shown, the main buoyancy adjustment unit 10 includes a base 101, a main piston assembly, a push rod assembly, and a main oil bladder 109. The main piston assembly includes a main piston outer wall 102, a main inner piston 103, and a main bellows 104. The lower end of the main piston outer wall 102 is fixed to the base 101 via screws or bolts, and the upper end of the main piston outer wall 102 is connected to the main inner piston 103 via the main bellows 104. The main bellows 104 is retractable and prevents water from entering the main piston assembly. The push rod device includes a servo push rod motor 105 and a push rod 106; the servo push rod motor 105 is fixedly installed on the base 101 by screws or bolts, and the servo push rod motor 105 is located inside the outer wall 102 of the main piston; the lower end of the push rod 106 is connected to the servo push rod motor 105, and the upper end of the push rod 106 is fixed with a top cover 107, and the top cover 107 is fixedly connected to the main inner piston 103; the servo push rod motor 105 controls the extension and contraction of the push rod 106, thereby driving the main inner piston 103 to move relative to the outer wall 102 of the main piston to adjust the volume of the main piston device, thereby achieving the purpose of adjusting the buoyancy. An oil bag base 108 is fixed to the upper end of the servo push rod motor 105, and a main oil bag 109 is fixedly installed on the oil bag base 108. The main oil bag 109 is located between the servo push rod motor 105 and the main inner piston 103. The main oil bag 109 has a corrugated folding structure and a hole in the middle for the push rod 106 to pass through. By injecting oil into the main oil bag 109, the movement of the main inner piston 103 can be assisted.

[0038] Function of the main buoyancy adjustment unit 10: In shallow water, the servo actuator motor 105 primarily drives the actuator 106, which in turn extends and retracts the main inner piston 103, adjusting buoyancy through volume changes. In deep water, if the thrust of the actuator 106 is insufficient, the main oil bladder 109 is used to assist in buoyancy adjustment. Oil is injected from the bottom oil tank 50 through the main oil bladder pipe 110 into the main oil bladder 109, controlling the robot's ascent.

[0039] like Figure 3-4 As shown, the right buoyancy regulating unit 20 and the left buoyancy regulating unit 30 are symmetrically arranged on either side of the main buoyancy regulating unit 10 and have the same structure, each comprising a side piston outer wall 201, a side inner piston 202, a side bellows 203, and a side oil bladder 204. One end of the side piston outer wall 201 is fixedly mounted on the central cavity 401, and the other end is connected to the side inner piston 202 via the side bellows 203. The side bellows 203 is retractable and prevents water from entering the interior of the piston. The side oil bladder 204 is fixedly mounted on the central cavity 401 and located inside the side piston outer wall 201. By injecting oil into the side oil bladder 204, the side inner piston 202 is pushed relative to the side piston outer wall 201 to adjust the piston volume and achieve the purpose of adjusting buoyancy.

[0040] like Figure 5 As shown, the buoyancy adjustment unit 40 comprises a central cavity 401, a transverse drive mechanism, a crossbar 404, and an electromagnet 405. The central cavity 401 is mounted below the base 101. The lateral piston outer walls 201 of the right and left buoyancy adjustment units 20 and 30 are symmetrically mounted on either side of the central cavity 401. Through holes for the crossbar 404 are provided in the central cavity 401, the lateral oil bladders 204, and the central portions of the lateral inner pistons 202. The crossbar 404 extends transversely through the central cavity 401 and the right and left buoyancy adjustment units 20 and 30, and is perpendicular to the push rod 106. Two electromagnets 405 are fixedly mounted on the left and right ends of the crossbar 404. When energized, the two electromagnets 405 adhere to the outer end walls of the left and right lateral inner pistons 202, respectively. The transverse drive mechanism drives the crossbar 404 to move left and right, thereby adjusting the buoyancy.

[0041] like Figure 6As shown, the transverse drive device includes a servo motor 402 and a reduction gearbox 403. The reduction gearbox 403 is equipped with a worm 410 output shaft, which is used to drive the crossbar 404 to move horizontally. Specifically, a rack 406 is fixedly mounted on the crossbar 404, which is compatible with the output shaft of the worm 410. The servo motor 402 drives the output shaft of the worm 410 to rotate, thereby driving the crossbar 404 to move horizontally. A guide rail 407 is fixedly mounted on the crossbar 404 on the side opposite the rack 406. A guide rail slider 408 is fixedly mounted on the central cavity 401. The guide rail 407 and the guide rail slider 408 slide in engagement. Specifically, the guide rail slider 408 has a groove in the shape of the guide rail 407. The guide rail slider 408 is equipped with a displacement sensor 409 to detect the sliding distance of the crossbar 404. Limiting baffles are provided at both ends of the guide rail 407 to limit the displacement of the crossbar 404 and prevent the lateral inner piston 202 from separating from the lateral piston outer wall 201.

[0042] Under normal circumstances, the left and right buoyancy adjustment units offset water pressure through crossbars 404. Driven by electromagnets 405, crossbars 404 and the left and right buoyancy adjustment units move synchronously, driven by servo reduction worms 410, to adjust buoyancy. Under normal operating conditions, the oil bladders in the main buoyancy adjustment unit 10 are primarily responsible. In an emergency, electromagnets 405 are de-energized, and the left and right side oil bladders 204 begin to fill with oil, pushing open the side inner pistons 202 and providing additional buoyancy. At this point, all three bladders are filled with oil, the pistons are pushed out to their maximum length, and buoyancy is maximized.

[0043] For further optimization, a depth gauge 411 is also installed on the buoyancy regulating device to monitor the working status of the device.

[0044] Further optimization, such as Figure 7 As shown, the buoyancy control device also includes an oil storage tank 50, which houses an oil pump 51. One end of the oil pump 51 has an oil inlet and an oil outlet for connecting to an external oil tank. The other end of the oil pump 51 has three oil pipe ports. The main oil bladder 109 is connected to one of the ports via a main oil bladder oil pipe 110, and the left and right side oil bladders 204 are connected to the other two ports via side oil bladder oil pipes 205. These three ports allow for independent oil flow. Each of the five inlet and outlet ports of the oil pump 51 is equipped with an independent solenoid valve, which allows for flexible control of the oil circuit.

[0045] For further optimization, in this embodiment, the main bellows 104 and the side bellows 203 are made of silicone bellows.

[0046] Accordingly, the present invention also proposes a method for adjusting the buoyancy of an underwater vehicle using the aforementioned buoyancy adjustment device. The buoyancy adjustment is divided into two operating modes: shallow water and deep water. In the shallow water operating mode, the push rod 106 drives the main bellows 104 to expand and contract, thereby changing the volume of the main piston device and adjusting the buoyancy. In the deep water operating mode, due to increased water pressure, the working environment of the electric push rod 106 is poor, and the deep water mode is switched to control the robot's buoyancy by injecting oil into the main oil bladder 109 to assist the push rod 106 in extending. In the emergency buoyancy mode, the lateral oil bladders 204 on both sides are injected with oil to push open the lateral inner piston 202 to provide additional buoyancy. Alternatively, the main oil bladder 109 can be simultaneously injected with oil to assist the push rod 106 in rapidly extending, thereby achieving rapid buoyancy.

[0047] Furthermore, the present invention can also adjust the buoyancy distribution of the underwater vehicle through the floatation adjustment unit 40, thereby adjusting the hovering posture. When the underwater vehicle needs to tilt left underwater, the servo motor 402 drives the output shaft of the worm 410 to translate rightward, reducing the piston volume of the left buoyancy adjustment unit 30 and increasing the piston volume of the right buoyancy adjustment unit 20. This shifts the center of buoyancy to the right, making the device higher on the right and lower on the left, thus completing the left-tilt floatation adjustment. When the underwater vehicle needs to tilt right underwater, the servo motor 402 drives the output shaft of the worm 410 to translate leftward. Because the left and right lateral bellows 203 are connected to the left and right lateral inner pistons 202, which are in turn fixed to the left and right ends of the crossbar 404, the total volume of the device does not change during translation, and the overall buoyancy remains unchanged. By slowly changing the position of the crossbar 404, floatation adjustment can be completed during underwater hovering.

[0048] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0049] The size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0050] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A buoyancy regulating device for an underwater vehicle, characterized in that: It includes a main buoyancy adjustment unit, a right buoyancy adjustment unit and a left buoyancy adjustment unit; The main buoyancy adjustment unit includes a base, a main piston device, a push rod device and a main oil bag; the main piston device includes an outer wall of the main piston, a main inner piston and a main bellows, the lower end of the outer wall of the main piston is installed on the base, and the upper end is connected to the main inner piston through the main bellows; the push rod device includes a servo push rod motor and a push rod, the servo push rod motor is installed on the base and is located inside the outer wall of the main piston, the lower end of the push rod is connected to the servo push rod motor, and the upper end is connected to the main inner piston, and the push rod is controlled by the servo push rod motor to extend and retract, thereby driving the main inner piston to move relative to the outer wall of the main piston to adjust the volume of the main piston device; the main oil bag is installed between the servo push rod motor and the main inner piston, and a hole for the push rod to pass through is provided in the middle of the main oil bag, and the movement of the main inner piston is assisted by filling oil into the main oil bag; The right buoyancy regulating unit and the left buoyancy regulating unit are symmetrically arranged on both sides of the main buoyancy regulating unit and have the same structure. They both include a side piston outer wall, a side inner piston, a side bellows and a side oil bag. The side piston outer wall and the side inner piston are connected by a side bellows. The side oil bag is arranged between the inner end of the side piston outer wall and the side inner piston. By injecting oil into the side oil bag, the side inner piston is pushed to move to adjust the piston volume.

2. The underwater vehicle buoyancy regulating device according to claim 1, characterized in that: The buoyancy adjustment device also includes a buoyancy adjustment unit, which includes a central cavity, a transverse driving device, a cross bar and an electromagnet; the central cavity is installed under the base, and the outer walls of the side pistons of the right buoyancy adjustment unit and the left buoyancy adjustment unit are symmetrically installed on the left and right sides of the central cavity; the cross bar transversely passes through the central cavity and the right buoyancy adjustment unit and the left buoyancy adjustment unit; the two electromagnets are respectively installed on the left and right ends of the cross bar, and when powered on, the two electromagnets are respectively adsorbed on the outer end walls of the left and right side inner pistons; the transverse driving device is used to drive the cross bar to move left and right, thereby realizing the adjustment of the buoyancy.

3. The underwater vehicle buoyancy regulating device according to claim 2, characterized in that: The middle of the central cavity, the side oil bag and the side inner piston are all provided with through holes for the cross rod to pass through. The cross rod passes through the central cavity, the side oil bag and the inner end wall of the side inner piston in sequence, and the cross rod is perpendicular to the push rod.

4. The underwater vehicle buoyancy regulating device according to claim 2, characterized in that: The transverse driving device includes a servo motor and a reduction gear box. The reduction gear box is provided with a worm output shaft. The cross bar is provided with a rack adapted to the worm output shaft. The servo motor drives the worm output shaft to rotate, thereby driving the cross bar to move left and right.

5. The underwater vehicle buoyancy regulating device according to claim 2, characterized in that: A guide rail is fixedly mounted on the cross bar, a guide rail slider is fixedly mounted on the central cavity, the guide rail and the guide rail slider are slidably matched, and a displacement sensor is provided on the guide rail slider for detecting the sliding distance of the cross bar.

6. The underwater vehicle buoyancy regulating device according to claim 5, characterized in that: Limit baffles are provided at both ends of the guide rail to limit the displacement of the cross bar and prevent the side inner piston from separating from the side piston outer wall.

7. The underwater vehicle buoyancy regulating device according to claim 1, characterized in that: The buoyancy regulating device is also equipped with a depth gauge.

8. The underwater vehicle buoyancy regulating device according to claim 1, characterized in that: The buoyancy regulating device also includes an oil storage tank, in which an oil pump is provided. One end of the oil pump is provided with an oil inlet and an oil outlet for connecting to an external oil tank; the other end of the oil pump is provided with three oil pipe openings, the main oil bag is connected to one oil pipe opening through the main oil bag oil pipe, and the side oil bags on the left and right sides are connected to the other two oil pipe openings through the side oil bag oil pipes respectively.

9. A method for adjusting the buoyancy of an underwater vehicle, characterized in that: The buoyancy regulating device according to any one of claims 1 to 8 is adopted. When working in shallow water, the volume of the main piston device is changed by the push rod driving the main bellows to expand and contract, thereby adjusting the buoyancy; when working in deep water, due to the increase in water pressure, the working environment of the electric push rod is not good, and the robot is controlled to float by injecting oil into the main oil bag to assist the extension of the push rod; in the emergency floating state, the side inner piston is pushed open by injecting oil into the side oil bags on both sides to provide additional buoyancy, or the main oil bag is injected with oil at the same time to assist the push rod to extend quickly, thereby achieving rapid floating.

10. The underwater vehicle buoyancy adjustment method according to claim 9, characterized in that: The suspension posture of the underwater vehicle is adjusted by the buoyancy adjustment unit. When the underwater vehicle needs to tilt to the left underwater, the servo motor drives the worm output shaft to translate to the right, so that the piston volume of the left buoyancy adjustment unit decreases and the piston volume of the right buoyancy adjustment unit increases, thereby causing the center of buoyancy to shift to the right, the device is higher on the right and lower on the left, and the left-tilt buoyancy adjustment is completed; when the underwater vehicle needs to tilt to the right underwater, the servo motor drives the worm output shaft to translate to the left.

Images