CN115092367A

CN115092367A - Small-size AUV's buoyancy adjusting device

Info

Publication number: CN115092367A
Application number: CN202210435971.3A
Authority: CN
Inventors: 杜晓旭; 李淼; 杨卓燊; 潘光; 宋保维; 宋东
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2022-04-24
Filing date: 2022-04-24
Publication date: 2022-09-23

Abstract

The invention relates to a buoyancy adjusting device of a small AUV (autonomous Underwater vehicle), belonging to the field of AUV buoyancy adjustment; the buoyancy control device comprises a power module, a transmission module, a buoyancy control module and a fixing module, wherein the power module is used for providing power for the buoyancy control module to realize buoyancy regulation control; the power module is connected with the buoyancy control module through the transmission module to realize power transmission; the displacement volume change of the AUV is realized through the buoyancy control module, so that the buoyancy of the AUV is changed; and the fixed module is used for fixedly connecting other modules with the AUV. The invention changes the drainage volume of the AUV through the buoy, can accurately adjust the net buoyancy of the AUV within a certain depth range, and has the advantages of simple structure, small occupied volume and high response speed.

Description

Small-size AUV's buoyancy adjusting device

Technical Field

The invention belongs to the field of AUV buoyancy adjustment, and particularly relates to a small AUV buoyancy adjustment device.

Background

With the continuous forward development of human society, material civilization will gradually advance to higher levels along with mental civilization, and oceans as a source of life will be further more fully developed and utilized. At present, all countries in the world pay attention to the value of ocean resources, respective technologies related to ocean resource development and utilization are developed, and competition is very strong. The problem to be solved is how to design an underwater exploration device which meets the actual requirements and how to improve the structural and performance parameters of the devices. At present, many colleges and scientific research institutions at home and abroad carry out careful research on small and medium AUVs, including the important aspects of AUVs such as recovery and distribution, propulsion performance, heavy buoyancy adjustment and the like. The existing AUV heavy buoyancy adjustment will be briefly classified and described below.

According to the relation between the gravity and the buoyancy of the object, the net buoyancy of the object in the fluid (generally water) can be changed by changing the gravity or the displacement volume of the object, and various existing AUV buoyancy adjusting devices which are put into use or not put into use are based on the principle. Some early AUVs change self gravity through carrying the weight that can once only unload, change holistic focus through removing some big mass weights in the body, though this kind of mode simple structure, nevertheless once only navigation adjusts the chance, and the volume that the weight account for is great, still can cause extra environmental burden. The self-gravity-changing type submersible pump is improved to achieve the purpose of changing the self gravity by exchanging mass with external fluid, namely sucking or discharging a part of fluid, the mode can be adjusted repeatedly, and the submersible pump can submerge or suspend at a fixed depth, but the structure of the adjusting device is complex, and the adjusting amplitude is generally small. The other idea is to change the water discharge volume of the AUV, and some schemes change the volume of the oil bag through an external oil bag and an oil pump pipeline system to achieve the purpose of changing the water discharge volume, and the water discharge volume change can be accurately controlled in the mode, but an oil tank is required to be arranged in the AUV, so that the AUV occupies a larger volume, a complicated pipeline system is required, and the AUV comprises various valve switches and other control elements, so that the device cost is higher, and the control system is more complicated. The other scheme is that two or more materials capable of thermal deformation are filled in a certain position of the AUV by means of the bionics principle, and the purpose of changing the AUV drainage volume is achieved by utilizing the deformation with corresponding amplitude generated by the temperature change of the marine environment where the AUV is located. Other ways, such as changing the volume of water to be removed by generating gas through chemical reaction, are not easy to control and have small adjustment amount, and are not described in detail herein.

Disclosure of Invention

The technical problem to be solved is as follows:

in order to avoid the defects of the prior art, the invention provides a buoy type buoyancy regulating device which is applied to a small AUV; because the small and medium-sized AUV is more easily influenced by various uncertain parameters in the underwater navigation process, the floating or sinking depth and speed of the AUV need to be finely adjusted, and the existing AUV heavy buoyancy adjusting device has a complex structure and a large volume ratio; based on the structure, the invention changes the drainage volume of the AUV through the buoy, can accurately adjust the net buoyancy of the AUV within a certain depth range, and has the advantages of simple structure, small occupied volume and high response speed.

The technical scheme of the invention is as follows: a buoyancy adjusting device of a small AUV comprises a power module, a transmission module, a buoyancy control module and a fixing module,

the power module provides power for the buoyancy control module to realize buoyancy regulation control;

the power module is connected with the buoyancy control module through the transmission module to realize power transmission;

the displacement volume change of the AUV is realized through the buoyancy control module, so that the buoyancy of the AUV is changed;

and the fixed module is used for fixedly connecting other modules with the AUV.

The further technical scheme of the invention is as follows: the power module comprises a motor, an input shaft, an output shaft, a high-speed gear and a low-speed gear, wherein a rotating shaft of the motor is coaxially connected with the input shaft, and the high-speed gear is arranged on the input shaft; the low-speed gear is arranged on the output shaft and is meshed with the high-speed gear;

the motor drives the input shaft to sequentially drive the high-speed gear, the low-speed gear and the output shaft to rotate, and power output is completed.

The further technical scheme of the invention is as follows: the rotating shaft of the motor is connected with the input shaft through a shaft sleeve; the input shaft is rotationally connected with the fixed module through an angular contact ball bearing, and the output shaft is rotationally connected with the fixed module through a cylindrical roller bearing.

The further technical scheme of the invention is as follows: the motor speed regulation device is characterized by further comprising a motor speed regulation module, wherein the motor speed regulation module comprises a variable frequency speed regulator, a timer and a control system and is used for regulating the rotating speed, the steering and the rotating turns of the motor and accurately controlling the moving distance and the moving speed of the buoy 7.

The further technical scheme of the invention is as follows: the transmission module comprises a screw rod, a nut, a starting position pressure sensor and an ending position pressure sensor; the screw rod is coaxially and fixedly connected with the output shaft, the nut is arranged on the screw rod through threads, and the rotary motion of the output shaft is converted into the linear reciprocating motion of the nut through the screw rod, so that power is transmitted to the buoyancy control module;

the starting position pressure sensor and the ending position pressure sensor are respectively arranged at the end part and the root part of the screw rod, are respectively used for sensing the limit positions of the nuts at the two ends of the screw rod, and simultaneously send signals to the controller, and the controller controls the forward and reverse rotation starting and stopping of the motor.

The further technical scheme of the invention is as follows: the screw rod and the output shaft are of an integral structure and are obtained by processing external threads on an axial extension part of the output shaft.

The invention further adopts the technical scheme that: the buoyancy control module comprises a buoy, a buoy rod, a buoy sliding sleeve and a buoy outer sealing bag sleeve; the AUV shell is provided with a through hole, the outer end of the buoy sliding sleeve is hermetically connected with the through hole, and the inner end of the buoy sliding sleeve is positioned in the AUV shell;

one end of the float is connected with the transmission module through a float rod, and the other end of the float is coaxially inserted into the float sliding sleeve; the transmission module transmits the power of the power module to the float cylinder rod, and the float cylinder rod drives the float cylinder to reciprocate in the float cylinder sliding sleeve along the axial direction; the displacement of the buoy in the buoy sliding sleeve is controlled to realize the displacement volume change of the AUV, so that the buoyancy adjustment of the AUV is completed;

the outer sealing bag of flotation pontoon cover suit is in the through-hole outer end of AUV for waterproof seal.

The further technical scheme of the invention is as follows: the buoy is a hollow part and is made of a buoyancy material; the molded surface of the other end of the AUV shell is consistent with the molded surface of the AUV shell.

The further technical scheme of the invention is as follows: float bowl slip cap and AUV casing integrated into one piece, the inner wall scribbles the drag reduction lubricating oil for the reciprocating motion of support float bowl.

The further technical scheme of the invention is as follows: the buoy outer sealing bag sleeve is made of elastic material and is coated on the surface of the protruding part when the buoy protrudes out of the AUV shell, so that a waterproof effect is achieved.

Advantageous effects

The invention has the beneficial effects that: the device mainly reforms a hydraulic oil cylinder or a water cylinder occupying a large volume, simplifies a mechanical structure, saves the internal space of the AUV, is simple and convenient to process, manufacture, install and use, and is suitable for quick and accurate buoyancy adjustment of the small AUV. In addition, the outer end surface of the buoy and the surface of the same area of the AUV pressure-bearing shell are in the same shape, so that the adverse interference of fluid power can be furthest reduced in the AUV submerging process, and meanwhile, the sealing performance at the position can be enhanced.

The invention provides a float type buoyancy regulating device of a small AUV (autonomous Underwater vehicle), which is characterized in that a movable float is used for replacing a hydraulic cylinder or a water cylinder, and the principle of generating buoyancy is to increase the drainage volume of the AUV, so that the AUV has certain negative buoyancy before the device is started and can submerge to a certain depth.

The motor, the gear mechanism, the lead screw nut machine and the floating mechanism are basically on the same axis, so that the transverse width of the whole device can be greatly reduced, the internal space of the AUV is greatly saved, and the AUV does not have material exchange with the outside in a working period, so that the sealing property of the AUV is ensured; meanwhile, the invention is mostly of a mechanical transmission structure, the control system is simple, the energy consumption elements are few, the energy consumption of the AUV in the working process is reduced, and the influence of the buoyancy regulating device on the navigation time of the AUV is avoided; the buoyancy adjusting device can quickly respond to the control instruction, so that the aircraft can quickly respond under the conditions of environmental change, instruction change and the like, and the maneuverability of the AUV is effectively improved.

Drawings

FIG. 1a is a schematic diagram of the front structure of the AUV buoyancy regulating device when buoyancy is not generated;

FIG. 1b is a schematic view of the back side of the AUV buoyancy regulating device when buoyancy is not generated

FIG. 2 is a schematic diagram of the structure of the transmission components of the AUV buoyancy adjustment device;

FIG. 3 is a schematic view of the installation position of the AUV buoyancy regulating device inside the AUV;

FIG. 4a is a schematic view of the position of the float during generation of buoyancy by the AUV buoyancy adjustment device;

FIG. 4b is a schematic view of the position of the buoys at maximum buoyancy generated by the AUV buoyancy adjustment device;

description of reference numerals: 1-low-speed gear, 2-high-speed gear, 3-output shaft support frame, 4-initial position pressure sensor, 5-nut, 6-buoy rod, 7-buoy, 8-base plate, 9-base plate fixing bolt and nut, 10-motor support frame, 11-matched rivet, 12-motor, 13-gear mounting frame, 14-base plate mounting frame, 15-buoy sliding sleeve, 16-buoy outer sealing bag sleeve, 17-AUV, 18-motor rotating shaft and input shaft connecting shaft sleeve, 19-ending position pressure sensor, 20-lead screw, 21-output shaft cylindrical roller bearing, 22-input shaft, 23-input shaft angular contact ball bearing, 24-thin flat key and 25-output shaft.

Detailed Description

The embodiments described below with reference to the accompanying drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like are used in the orientations and positional relationships indicated in the drawings, which are based on the orientation or positional relationship shown in the drawings, and are used merely for convenience in describing the invention and to simplify the description, but do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the invention.

The embodiment of the invention relates to a buoyancy regulating device of a small AUV (autonomous Underwater vehicle), which comprises a power module, a transmission module, a buoyancy control module and a fixing module, wherein the power module is used for providing power for the buoyancy control module to realize buoyancy regulation control; the power module is connected with the buoyancy control module through the transmission module to realize power transmission; the displacement volume change of the AUV is realized through the buoyancy control module, so that the buoyancy of the AUV is changed; and the fixed module is used for fixedly connecting other modules with the AUV.

The power module comprises a motor 12, a motor rotating shaft and input shaft connecting shaft sleeve 18, an input shaft 22, an output shaft 25, a high-speed gear 2, a low-speed gear 1, a thin flat key 24, an input shaft angular contact ball bearing 23 and an output shaft cylindrical roller bearing 21. The rotating shaft of the motor 12 is coaxially connected with an input shaft 22 through a motor rotating shaft and an input shaft connecting shaft sleeve 18, and the high-speed gear 2 is arranged on the input shaft 22; the low-speed gear 1 is arranged on the output shaft 25 and is meshed with the high-speed gear 2; the motor 12 drives the input shaft 22 to sequentially drive the high-speed gear 2, the low-speed gear 1 and the output shaft 25 to rotate, and power output is completed. Because the rotation speed of the input shaft 22 is relatively high, an angular contact ball bearing with small friction force is selected, and the rotation speed of the output shaft 25 is relatively low, and a cylindrical roller bearing with slightly large friction force is selected. Although the stepping motor can realize accurate speed regulation and rotation turn number control, the requirement of the device can be met by selecting a common motor with larger load as the motor part has smaller load capacity and higher cost and combining a variable-frequency speed regulator to adjust the rotating speed, the steering and the running time of the motor 12. The input shaft 22 and the output shaft 25 are in interference fit with the two rolling bearings, the positions of all parts of the whole mechanism can be kept through the position invariance of the bracket and the mounting rack, the mechanism can run stably, and a fixer can be additionally arranged at the bearing when necessary, and the device is not added.

The transmission module is composed of a screw rod 20, a nut 5, a starting position pressure sensor 4 and an ending position pressure sensor 19. The spindle 20 is produced by machining a thread in the extension of the output shaft 25. A start position pressure sensor 4 is additionally arranged on the side of the output shaft support frame 3 far away from the gear end for limiting the start limit position of the nut 5: the nut 5 moves in a return stroke in the reverse rotation process of the screw rod 20, when the nut contacts the pressure sensor 4 at the initial position, the sensor generates a pressure signal which is continuously increased from zero, the signal is compared with the safety pressure set in the controller, when the safety pressure reaches 80 percent, the controller sends a signal to stop the reverse rotation of the motor, and the return stroke is finished. Similarly, the end position pressure sensor 19 at the other end of the screw 20 functions similarly, and the combination of the two can ensure that the nut 5 moves in a safe position range on the screw 20.

The buoyancy control module consists of a buoy 7, a buoy rod 6, a buoy sliding sleeve 15 and a buoy outer sealing bag sleeve 16. The buoy 7 is a key part for generating positive buoyancy, has the largest volume and smaller mass, and is a common buoyancy material. The inner end of the floating cylinder rod is fixedly connected with a floating cylinder rod 6, the floating cylinder rod 6 is fixedly connected with a nut 5, and the floating cylinder rod can reciprocate under the drive of the nut 5; the displacement of the buoy in the buoy sliding sleeve is controlled to realize the displacement volume change of the AUV, and the buoyancy adjustment of the AUV is completed. The buoy sliding sleeve and the AUV 17 shell are integrally formed, and the inner wall of the buoy sliding sleeve is coated with anti-drag lubricating oil and can support the reciprocating motion of the buoy 7. The buoy outer sealing bag sleeve 16 has certain elasticity, and is coated on the surface of the protruding part when the buoy protrudes out of the AUV 17, so that a waterproof effect is achieved.

The fixing module is composed of a bottom plate 8, an output shaft support frame 3, a gear mounting frame 13, a motor support frame 10, a matched rivet 11, a bottom plate fixing bolt and nut 9 and a bottom plate mounting frame 14. The bottom plate 8 is mainly used for bearing, is embedded into a bottom plate mounting rack 14 of the AUV 17 and is fixed by using a bottom plate fixing bolt and a nut 9. The output shaft support 3 is used to support and fix the output shaft 25, and the gear mounting 13, the motor support bracket 10 and the mating rivet 11 function similarly.

The motor speed regulation module is composed of a variable frequency speed regulator, a timer and a corresponding control system. The combination of the variable-frequency speed regulator and the timer can adjust the rotating speed, the steering and the number of rotating turns of the motor 12, accurately control the moving distance and the moving speed of the buoy 7, and realize the underwater diving or floating of the AUV 17 at a fixed depth by combining the pressure, the temperature, the seawater flow dynamics information and the like obtained by detecting the navigation environment of the AUV 17 by other detection systems. The data of the pressure sensor can be processed by the control system to ensure the stability and safety of the device.

The following further describes embodiments of the present invention with reference to the drawings.

Fig. 1a is a schematic front view of the AUV buoyancy adjusting device when no buoyancy is generated. The motor, the gear mechanism, the lead screw nut machine and the floating cylinder mechanism of the device are basically on the same axis, so that the transverse width of the whole device can be greatly reduced, and the precious internal space of the AUV is saved. Since the float slip cap and the AUV are integrally formed, the float slip cap is not shown in fig. 1a, and in fact the output shaft and the float are supported by the float slip cap and the output shaft support bracket together, and the end position pressure sensor is just placed with a gap between the screw rod and the float rod. The surface shape of the outer end of the buoy is consistent with that of the AUV pressure-bearing shell at the same position, so that the consistency of the surface shape of the AUV can be effectively kept, the interference caused by fluid power is greatly reduced, and the load of an AUV control system is reduced.

FIG. 1b is a schematic view of the back side of the AUV buoyancy regulating device when buoyancy is not generated. Because the volume that the flotation pontoon occupied is great, the diameter is great, so the position of output shaft also leans on more, and the motor needs the support frame to support. In order to better fix the motor and reduce vibration interference, a fixing rivet is adopted for interference constraint.

Fig. 2 is a schematic structural diagram of a transmission part of the AUV buoyancy adjusting device, which has fewer parts and a simple structure. The thin flat key is used for transmitting the rotation of the gear to the rotating shaft, and the bearing is used for effectively reducing the friction resistance of the rotation of the shaft. The lead screw and nut mechanism is divided into two structures based on sliding friction and rolling friction principles, and in order to reduce the complexity and energy consumption of the device, the lead screw and nut mechanism with slightly lower transmission efficiency is adopted, so that self-locking can be formed, and the phenomenon that the floating barrel is pressed back by external pressure when the AUV is at a larger depth to cause the nut to move reversely is avoided. Just because of the existence of self-locking, the device can realize fixed-depth submergence or floating.

Fig. 3 is a schematic diagram showing the installation position of the AUV buoyancy adjusting device inside the AUV, the whole device is installed in the middle of the AUV, the longitudinal section of the buoy is also very close to the longitudinal section of the AUV, and the center of the generated buoyancy is close to the center of gravity of the AUV, so that the unstable influence on the AUV in the process of adjusting the buoyancy can be effectively reduced, and the work load of the gravity adjusting system can be reduced.

Fig. 4a is a schematic diagram showing the position of the buoy during the buoyancy generation process of the AUV buoyancy adjusting device, at this time, the device can generate partial buoyancy, and the AUV may be in three states of hovering, floating and submerging at a certain depth under water. Because the principle of buoyancy generated by the device is to increase the drainage volume of the AUV, the AUV has certain negative buoyancy before the device is started, and can submerge to a certain depth, and the specific maximum submerging depth is determined by the maximum pressure which can be borne by the AUV pressure-resistant shell. In the state shown in fig. 4a, the apparatus has generated partial buoyancy, but the gravity of the AUV is uncertain, so the buoyancy generated by the apparatus may be above or below its own gravity, and if it is greater than its own gravity, the AUV may float at a low speed; if the AUV is smaller than the self gravity, the AUV can submerge at a deceleration; if equal to its own weight, the AUV may hover at a certain depth under water.

Fig. 4b is a schematic diagram showing the position of the float when the AUV buoyancy adjusting device generates maximum buoyancy, where the buoyancy of the device is maximum and the AUV is in a state that the AUV may accelerate to float and float on the water. Because the buoyancy generated by the device is the maximum, the buoyancy is certainly greater than the self gravity of the AUV, and the difference value is also the maximum, so that the AUV can accelerate to float or float on the water surface.

Although embodiments of the present invention have been shown and described, it will be understood that the embodiments are illustrative and not restrictive, and that various changes, modifications, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The utility model provides a buoyancy adjustment device of small-size AUV which characterized in that: comprises a power module, a transmission module, a buoyancy control module and a fixing module,

and the fixed module is used for fixedly connecting other modules with the AUV.

2. The apparatus of claim 1, wherein the apparatus further comprises: the power module comprises a motor, an input shaft, an output shaft, a high-speed gear and a low-speed gear, wherein a rotating shaft of the motor is coaxially connected with the input shaft, and the high-speed gear is arranged on the input shaft; the low-speed gear is arranged on the output shaft and is meshed with the high-speed gear;

3. The apparatus of claim 2, wherein the buoyancy adjusting device of the small AUV comprises: the rotating shaft of the motor is connected with the input shaft through a shaft sleeve; the input shaft is rotationally connected with the fixed module through an angular contact ball bearing, and the output shaft is rotationally connected with the fixed module through a cylindrical roller bearing.

4. The apparatus of claim 2, wherein the apparatus further comprises: the motor speed regulation module comprises a variable frequency speed regulator, a timer and a control system and is used for adjusting the rotating speed, the steering number and the rotating turn number of the motor and accurately controlling the moving distance and the moving speed of the buoy.

5. The apparatus of claim 2, wherein the apparatus further comprises: the transmission module comprises a screw rod, a nut, an initial position pressure sensor and an end position pressure sensor; the screw rod is coaxially and fixedly connected with the output shaft, the nut is arranged on the screw rod through threads, and the rotary motion of the output shaft is converted into the linear reciprocating motion of the nut through the screw rod, so that power is transmitted to the buoyancy control module;

6. The apparatus of claim 5, wherein the buoyancy adjusting device comprises: the screw rod and the output shaft are of an integral structure and are obtained by processing external threads on an axial extension part of the output shaft.

7. The apparatus of claim 1, wherein the apparatus further comprises: the buoyancy control module comprises a buoy, a buoy rod, a buoy sliding sleeve and a buoy outer sealing bag sleeve; the AUV shell is provided with a through hole, the outer end of the buoy sliding sleeve is hermetically connected with the through hole, and the inner end of the buoy sliding sleeve is positioned in the AUV shell;

one end of the float is connected with the transmission module through a float rod, and the other end of the float is coaxially inserted into the float sliding sleeve; the transmission module transmits the power of the power module to the buoy rod, and the buoy rod drives the buoy to reciprocate in the buoy sliding sleeve along the axial direction; the displacement of the buoy in the buoy sliding sleeve is controlled to realize the displacement volume change of the AUV, so that the buoyancy adjustment of the AUV is completed;

8. The apparatus of claim 7, wherein the buoyancy adjusting device comprises: the buoy is a hollow part and is made of a buoyancy material; the molded surface of the other end of the AUV shell is consistent with the molded surface of the AUV shell.

9. The apparatus of claim 7, wherein the buoyancy adjusting device comprises: the flotation pontoon slip cap and AUV casing integrated into one piece, the inner wall scribbles drag reduction lubricating oil for support the reciprocating motion of flotation pontoon.

10. The apparatus of claim 7, wherein the buoyancy adjusting device comprises: the buoy outer sealing bag sleeve is made of elastic material and is coated on the surface of the protruding part when the buoy protrudes out of the AUV shell, so that a waterproof effect is achieved.