Multi-degree-of-freedom motion compensation system and method for AUV (Autonomous Underwater Vehicle) retraction operation

Abstract

The invention relates to the technical field of AUVs (Autonomous Underwater Vehicles), and particularly discloses a multi-degree-of-freedom motion compensation system and method for AUV retraction operation, the compensation system comprises a main body, the main body comprises an XY-direction compensation mechanism and a Z-direction compensation mechanism, the XY-direction compensation mechanism comprises a plurality of propellers, the Z-direction compensation mechanism comprises a hydraulic cylinder, a composite energy accumulator and a gas cylinder, the hydraulic cylinder comprises a first piston part, and the composite energy accumulator comprises a second piston part; an inner cavity of the hydraulic cylinder is divided into a rodless cavity and a rod cavity through a first piston piece, the composite energy accumulator comprises a cavity body, a fixed partition plate and a second piston piece are arranged in the cavity body, and the second piston piece comprises a first piston and a second piston which are connected with each other. The first piston, the fixed partition plate and the second piston divide the cavity into a connecting oil cavity, a first compensation oil cavity, a second compensation oil cavity and a compensation air cavity which are arranged in sequence, and communicating channels are arranged between the connecting oil cavity and the rod cavity and between the compensation air cavity and the air cylinder. A hydraulic control assembly capable of conducting bidirectional reciprocating conveying on hydraulic oil in the first compensation oil cavity and the second compensation oil cavity so as to change the oil amount in the first compensation oil cavity and the second compensation oil cavity is arranged between the first compensation oil cavity and the second compensation oil cavity. The compensation system is simple in overall structure, high in flexibility, good in compensation effect and capable of effectively ensuring the stability and safety of AUV retracting and releasing operation under complex sea conditions.

Description

Technical Field

[0001] The present invention relates to the field of AUV technology, and in particular to a multi-degree-of-freedom motion compensation system and method for AUV retrieval and launching operations. Background Art

[0002] Autonomous Underwater Vehicles (AUVs) play an important role in marine scientific investigation, underwater rescue, military reconnaissance, and seabed salvage. With the expansion of AUV applications, countries are increasing their investment in AUV research and development. Among them, the deployment and recovery of AUVs is one of the key technologies to achieve safe and continuous operation.

[0003] At present, the deployment and recovery methods of AUVs are mainly divided into surface deployment and recovery and underwater deployment and recovery. Among them, the surface deployment and recovery method includes a surface mother ship, a crane cable retracting system, and an underwater docking and recovery device. After completing the mission, the AUV needs to return to the mother ship area in time for energy replenishment, data upload, and mission download. At the same time, when the AUV is overhauled and maintained, it also needs to return to the mother ship through the underwater docking and recovery device and the crane system. Therefore, the spatial position stability of the docking and recovery device is extremely important.

[0004] In the existing technology, AUV mainly uses the winch-type active compensation crane system on the mother ship to offset the movement of the ship in the waves. However, when the water depth increases, the elasticity of the cable and the influence of the ocean current will increase, making it difficult to accurately control the docking recovery device at the end of the cable, making it difficult for the existing winch-type active compensation crane to achieve efficient and accurate connection between the AUV and the underwater docking recovery device in deep water and complex sea conditions. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-degree-of-freedom motion compensation system and method for AUV retracting and launching operations in view of the existing technical status.

[0006] The compensation system has a simple overall structure and is installed between the end of the crane cable and the AUV launching and retrieving device. It can directly and accurately compensate for the displacement of the AUV launching and retrieving device. It is easy to install and use, has higher flexibility and applicability, and has a good compensation effect. It can effectively reduce the impact of the movement of the operating vessel in complex sea conditions on the AUV launching and retrieving device, ensure the stability and safety of the AUV during the deployment and recovery process, reduce the risk of mission interruption and equipment damage due to docking failure, and achieve more efficient energy utilization and reduce unnecessary energy consumption.

[0007] In order to achieve the above object, the present invention adopts the following technical scheme:

[0008] The present invention provides a multi-degree-of-freedom motion compensation system for AUV retracting and launching operations, comprising a main body, wherein the main body comprises an XY compensation mechanism and a Z compensation mechanism.

[0009] The XY compensation mechanism includes a plurality of thrusters, the thrust direction of which is arranged along the vertical direction of the Z direction.

[0010] The Z-direction compensation mechanism includes a hydraulic cylinder, a composite accumulator and a gas cylinder.

[0011] The hydraulic cylinder comprises a first piston member for hoisting the AUV storage and launching device, and the inner cavity of the hydraulic cylinder is divided into a vacuum rodless cavity and a rod cavity filled with hydraulic oil by the first piston member.

[0012] The composite accumulator comprises a cavity, a fixed partition and a second piston member that can reciprocate relative to the fixed partition are arranged in the cavity, the second piston member comprises a first piston and a second piston that are connected to each other, the first piston and the second piston are respectively arranged on both sides of the fixed partition, the first piston, the fixed partition and the second piston divide the cavity into a connecting oil chamber, a first compensation oil chamber, a second compensation oil chamber and a compensation air chamber that are arranged in sequence,

[0013] A connecting passage is provided between the connecting oil chamber and the rod chamber, and between the compensating air chamber and the gas cylinder. A hydraulic control component is provided between the first compensating oil chamber and the second compensating oil chamber, which can transport the hydraulic oil inside the two chambers back and forth in both directions to change the amount of oil inside the two chambers.

[0014] In some embodiments, the first piston member is disposed on the center of gravity of the body.

[0015] In some embodiments, the main body is provided with an integrated shell, the integrated shell is provided with an installation cavity, the XY compensation mechanism and the Z compensation mechanism are provided in the installation cavity, the thruster at least partially extends from the installation cavity to the outside of the installation cavity, and the outer shell is provided with a telescopic opening for allowing the first piston member to be telescoped inside and outside the installation cavity.

[0016] In some embodiments, the shell includes a side wall formed by four side walls, and the cross-section of the side wall in the vertical direction of the Z direction is a hollow rectangular structure. A propeller is correspondingly arranged on each side wall, and the propellers of each propeller are symmetrically arranged in pairs.

[0017] In some embodiments, it also includes a power supply, a monitoring component and an industrial computer. The monitoring component is used to collect current actual sea condition data and the current motion state of the main body. The industrial computer can receive the data collected by the monitoring component and predict the motion state of the main body, and control the XY compensation mechanism and the Z compensation mechanism to perform motion compensation according to the predicted motion state.

[0018] In some embodiments, a hydraulic throttle valve is provided between the connecting oil chamber and the rod chamber, and an exhaust throttle valve is provided between the compensating air chamber and the gas cylinder.

[0019] In some embodiments, the hydraulic control assembly includes a drive motor and a bidirectional pump for conveying hydraulic oil, and the bidirectional pump is respectively connected to the first compensation oil chamber and the second compensation oil chamber.

[0020] The present invention provides a compensation method for a multi-degree-of-freedom motion compensation system for AUV retracting and launching operations, comprising:

[0021] The main body is installed between the crane and the AUV retracting and launching device.

[0022] Real-time collection of current sea conditions data and the current subject's motion status,

[0023] According to the collected current sea condition data and the current motion state of the subject, the motion state of the subject is predicted based on an extremely short-term prediction algorithm,

[0024] The XY compensation mechanism and the Z compensation mechanism are controlled to perform motion compensation according to the predicted motion state.

[0025] In some embodiments, the compensation method includes:

[0026] During the AUV deployment process, the AUV and the AUV retracting and launching device are lowered to the target water depth, and during the lowering process, the compensation system is controlled to continuously perform motion compensation on the AUV retracting and launching device;

[0027] During the AUV recovery process, after the AUV arrives near the AUV retracting and launching device, the compensation system is controlled to perform motion compensation on the AUV retracting and launching device, so that the AUV retracting and launching device is stabilized at a certain position underwater, and then the AUV and the AUV retracting and launching device are docked.

[0028] In some embodiments, the compensation method includes:

[0029] The oil volume in both the first compensation oil chamber and the second compensation oil chamber is adjusted by the hydraulic control component to adjust the compensation volume in the Z direction.

[0030] The beneficial effects of the present invention are:

[0031] In the present invention, on the one hand, by setting a plurality of thrusters arranged in the vertical direction of the Z direction as the XY compensation mechanism, the lateral and circumferential movements of the AUV launching and retracting device can be compensated when the AUV is launched and retracted. When thrusters are used in the X, Y and Z directions, the thrusters in the vertical and horizontal directions will cause the flow field distribution of the surrounding water to change more complicatedly, increase the difficulty of compensation control, and affect the accuracy of compensation. The present invention adopts a Z compensation mechanism composed of a hydraulic cylinder, a composite accumulator, a hydraulic control component and a gas cylinder, which can compensate for the movement of the AUV launching and retracting device in the heave direction when the AUV is launched and retracted. The XY compensation mechanism cooperates with the Z compensation mechanism to perform multi-degree-of-freedom motion compensation on the AUV launching and retracting device, effectively reducing the impact of the movement of the operating vessel in complex sea conditions on the AUV launching and retracting device, ensuring the stability and safety of the AUV during deployment and recovery, reducing the risk of mission interruption and equipment damage due to docking failure, and effectively avoiding the problems of increased difficulty and decreased accuracy of compensation control caused by the use of thrusters in the X, Y and Z directions.

[0032] On the other hand, the Z-direction compensation mechanism is composed of a hydraulic cylinder, a composite accumulator, a hydraulic control component and a gas cylinder, wherein the composite accumulator is composed of a connecting oil chamber, a first compensation oil chamber, a second compensation oil chamber and a compensation air chamber. The hydraulic control component is used to adjust the oil volume inside the first compensation oil chamber and the second compensation oil chamber in the composite accumulator to realize the active compensation function of the load on the hydraulic cylinder. The hydraulic cylinder, the gas cylinder, the connecting oil chamber and the compensation air chamber in the composite accumulator form a stiffness damping system similar to passive compensation, which effectively absorbs and buffers vibration energy. The hydraulic control component adjusts the oil volume inside the first compensation oil chamber and the second compensation oil chamber, and can also change the proportion of active compensation in the compensation amount of the entire Z-direction compensation mechanism, so that the compensation amount of active compensation can be flexibly adjusted according to different sea conditions and operation requirements, which is more flexible and can achieve more efficient energy utilization and reduce unnecessary energy consumption while ensuring the heave compensation effect.

[0033] The compensation system has a simple overall structure and is installed between the end of the crane cable and the AUV launching and retrieving device. It can directly and accurately compensate for the displacement of the AUV launching and retrieving device. It is easy to install and use, has higher flexibility and applicability, and has a good compensation effect. It can effectively reduce the impact of the movement of the operating vessel in complex sea conditions on the AUV launching and retrieving device, ensure the stability and safety of the AUV during the deployment and recovery process, reduce the risk of mission interruption and equipment damage due to docking failure, and achieve more efficient energy utilization and reduce unnecessary energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The present invention is a schematic diagram of the use of a multi-degree-of-freedom motion compensation system for AUV retrieval and deployment operations.

[0035] Figure 2 It is a schematic diagram of the assembly of a multi-degree-of-freedom motion compensation system for AUV retrieval and deployment operations and an AUV retrieval and deployment device according to the present invention.

[0036] Figure 3 The present invention is a schematic structural diagram of a degree of freedom motion compensation system for AUV retrieval and deployment operations.

[0037] Figure 4 The figure is a schematic diagram of the principle of a degree of freedom motion compensation system for AUV retrieval and deployment operations according to the present invention.

[0038] Figure 5 The present invention is a flow chart of a compensation method of a multi-degree-of-freedom motion compensation system for AUV launching and retracting operations. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in further detail below.

[0040] See also Figures 1 to 4 As shown, this embodiment provides a multi-degree-of-freedom motion compensation system for AUV retracting and launching operations, including a main body 2, wherein the main body 2 includes an XY compensation mechanism 3 and a Z compensation mechanism 4.

[0041] The XY compensation mechanism 3 includes a plurality of thrusters 31, and the thrust direction of the thrusters 31 is arranged along the vertical direction of the Z direction.

[0042] The Z-direction compensation mechanism 4 includes a hydraulic cylinder 41, a composite accumulator 42 and a gas cylinder 43.

[0043] The hydraulic cylinder 41 includes a first piston member 411 for hoisting the AUV storage and launching device 13. The inner cavity of the hydraulic cylinder 41 is divided into a vacuum rodless cavity 412 and a rod cavity 413 filled with hydraulic oil by the first piston member 411.

[0044] The composite accumulator 42 includes a cavity 421, in which a fixed partition 422 and a second piston member 423 that can reciprocate relative to the fixed partition 422 are provided. The second piston member 423 includes a first piston and a second piston that are connected to each other. The first piston and the second piston are respectively arranged on both sides of the fixed partition 422. The first piston, the fixed partition 422 and the second piston divide the cavity 421 into a connecting oil chamber 424, a first compensation oil chamber 425, a second compensation oil chamber 426 and a compensation air chamber 427 that are arranged in sequence.

[0045] A connecting passage is provided between the connecting oil chamber 424 and the rod chamber 413, and between the compensating air chamber 427 and the gas cylinder 43. A hydraulic control component 44 is provided between the first compensating oil chamber 425 and the second compensating oil chamber 426, which can carry out bidirectional reciprocating transportation of the hydraulic oil inside the two chambers to change the amount of oil inside the two chambers.

[0046] During installation, the main body 2 is suspended between the end of the cable of the crane and the AUV retracting and releasing device 13 . Specifically, the rod chamber 413 of the hydraulic cylinder 41 is installed downward, and the piston rod of the first piston member 411 is connected to the AUV retracting and releasing device 13 .

[0047] The compensation system of the present invention can perform multi-degree-of-freedom motion compensation on the AUV launching and retracting device 13, specifically:

[0048] 1) XY motion compensation (lateral and circumferential motion compensation):

[0049] By adjusting the thrust of each thruster 31 in the XY compensation mechanism 3, since the thrust direction of the thruster 31 is set along the vertical direction of the Z direction, the lateral and circumferential movements of the AUV storage and launching device 13 can be compensated, thereby ensuring the horizontal position stability of the AUV storage and launching device 13.

[0050] 2) Z-direction motion compensation (heave motion compensation):

[0051] In the present invention, the Z-direction compensation mechanism 4 is mainly composed of a hydraulic cylinder 41, a composite accumulator 42, a gas cylinder 43 and a hydraulic control assembly 44, which together form a heave compensation structure that has both active compensation and can effectively absorb and buffer vibration energy. Specifically, the load transmission pressure borne by the hydraulic cylinder 41 is given to the connecting oil chamber 424 of the composite accumulator 42, and the hydraulic control assembly 44 performs two-way reciprocating transmission of the hydraulic oil inside the first compensation oil chamber 425 and the second compensation oil chamber 426 to change the oil volume inside the two, compensate part of the pressure, and the compensation gas chamber 427 compensates the remaining force, wherein the force of the compensation gas chamber 427 is provided by the gas cylinder 43.

[0052] On the one hand, the hydraulic control component 44 adjusts the oil volume in the first compensation oil chamber 425 and the second compensation oil chamber 426 in the composite accumulator 42 to realize the active compensation function of the load on the hydraulic cylinder 41. Specifically, the compensation principle of the active compensation function is as follows:

[0053] When it is monitored that the AUV storage and launching device 13 has a downward trend, the hydraulic oil inside the second compensation oil chamber 426 is transported to the first compensation oil chamber 425 through the hydraulic control component 44, and the second piston member 423 is pressed toward the connecting oil chamber 424, thereby increasing the pressure in the rod chamber 413 of the hydraulic cylinder 41, and assisting the first piston member 411 of the hydraulic cylinder 41 to quickly retract upward, thereby suppressing the descent of the AUV storage and launching device 13 and achieving the effect of the active compensation function.

[0054] When it is monitored that the AUV storage and launching device 13 has an upward trend, the hydraulic oil inside the first compensation oil chamber 425 is transported to the second compensation oil chamber 426 through the hydraulic control component 44, and the second piston member 423 moves in the direction away from the connecting oil chamber 424, reducing the pressure in the rod chamber 413 of the hydraulic cylinder 41. Under the synergistic effect of the gravity of the AUV storage and launching device 13, the first piston member 411 of the hydraulic cylinder 41 quickly extends downward, suppressing the rise of the AUV storage and launching device 13, thereby achieving the effect of the active compensation function.

[0055] At the same time, the adjustment of the oil volume inside the first compensation oil chamber 425 and the second compensation oil chamber 426 by the hydraulic control component 44 can also change the proportion of active compensation in the entire Z-direction compensation mechanism 4. For example, when it is monitored that the AUV retracting and launching device 13 has a downward trend, the more oil the hydraulic control component 44 delivers from the second compensation oil chamber 426 to the first compensation oil chamber 425, the greater the force applied to the connecting oil chamber 424, and the greater the compensation amount.

[0056] On the other hand, if the first compensation oil chamber 425, the second compensation oil chamber 426 and the second piston member 423 in the compound accumulator 42 are regarded as an integral piston, the hydraulic cylinder 41, the gas cylinder 43, the connecting oil chamber 424 and the compensation gas chamber 427 in the compound accumulator 42 form a stiffness damping system similar to passive compensation, which can effectively absorb and buffer vibration energy.

[0057] In the present invention, on the one hand, by setting a plurality of thrusters 31 arranged in the vertical direction of the Z direction as the XY compensation mechanism 3, the lateral and circumferential movements of the AUV stowage device 13 can be compensated when the AUV 12 is stowed. When thrusters are used in the X, Y and Z directions, the vertical and horizontal thrusters will cause the flow field distribution of the surrounding water to be more complicated, increase the difficulty of compensation control, and affect the accuracy of compensation. The present invention adopts a Z-direction compensation mechanism 4 composed of a hydraulic cylinder 41, a composite accumulator 42, a hydraulic control assembly 44 and a gas cylinder 43, which can It is able to compensate for the movement of the AUV launching and retracting device 13 in the heave direction when the AUV 12 is launched and retracted. The XY compensation mechanism 3 and the Z compensation mechanism 4 cooperate with each other to perform multi-degree-of-freedom motion compensation for the AUV launching and retracting device 13, effectively reducing the impact of the movement of the operating vessel 11 under complex sea conditions on the AUV launching and retracting device 13, ensuring the stability and safety of the AUV 12 during deployment and recovery, reducing the risk of mission interruption and equipment damage due to docking failure, and effectively avoiding the problems of increased difficulty and decreased accuracy of compensation control caused by the use of thrusters in the X, Y and Z directions.

[0058] On the other hand, the Z-direction compensation mechanism 4 is composed of a hydraulic cylinder 41, a composite accumulator 42, a hydraulic control assembly 44 and a gas cylinder 43, wherein the composite accumulator 42 is composed of a connecting oil chamber 424, a first compensation oil chamber 425, a second compensation oil chamber 426 and a compensation gas chamber 427. The hydraulic control assembly 44 is used to adjust the oil volume in the first compensation oil chamber 425 and the second compensation oil chamber 426 in the composite accumulator 42 to realize the active compensation function of the load on the hydraulic cylinder 41. The connecting oil chamber 424 and the compensating air chamber 427 form a stiffness damping system similar to passive compensation, which effectively absorbs and buffers vibration energy. The hydraulic control component 44 adjusts the oil volume inside the first compensation oil chamber 425 and the second compensation oil chamber 426, and can also change the proportion of active compensation in the entire Z-direction compensation mechanism 4, so that the compensation amount of active compensation can be flexibly adjusted according to different sea conditions and operation requirements, which is more flexible and can achieve more efficient energy utilization and reduce unnecessary energy consumption while ensuring the heave compensation effect.

[0059] The compensation system has a simple overall structure and is installed between the end of the crane cable and the AUV launching and retrieving device 13. It can directly and accurately compensate for the displacement of the AUV launching and retrieving device 13. It is easy to install and use, has higher flexibility and applicability, and has a good compensation effect. It can effectively reduce the impact of the movement of the operating vessel 11 under complex sea conditions on the AUV launching and retrieving device 13, ensure the stability and safety of the AUV 12 during the deployment and recovery process, reduce the risk of mission interruption and equipment damage due to docking failure, and achieve more efficient energy utilization and reduce unnecessary energy consumption.

[0060] In some embodiments, the first piston member 411 is disposed on the center of gravity of the main body 2. Since the first piston member 411 is connected to the AUV retracting and launching device 13, disposing the first piston member 411 on the center of gravity of the main body 2 is more conducive to reducing the difficulty of compensation and improving the accuracy of compensation.

[0061] Specifically, the telescopic end of the first piston member 411 uses a lifting ring, and is rigidly connected to the AUV retracting and launching device 13 through the lifting ring.

[0062] In some embodiments, see Figures 1 to 3 As shown, the main body 2 is provided with an integrated shell, the integrated shell is provided with an installation cavity, the XY compensation mechanism 3 and the Z compensation mechanism 4 are provided in the installation cavity, the thruster 31 at least partially extends from the installation cavity to the outside of the installation cavity, and the outer shell is provided with a telescopic opening for allowing the first piston member 411 to be telescoped inside and outside the installation cavity. The compensation system has a high degree of integration and is more convenient to use, install and maintain.

[0063] In some embodiments, the propeller 31 is a rotary propeller, and the propeller 31 includes a power component and a rotary propeller.

[0064] In some embodiments, see Figure 3 As shown, the shell includes a side wall enclosed by four side walls 51, and the cross-section of the side wall in the vertical direction of the Z direction is a hollow rectangular structure. A propeller 31 is correspondingly arranged on each side wall 51, and the propellers of each propeller 31 are symmetrically arranged in pairs. The need for lateral and circumferential motion compensation requires controlling the working state of the propeller 31. The coordinated arrangement of the shell and the propeller 31 can effectively reduce the control difficulty of lateral and circumferential motion compensation.

[0065] In some embodiments, it also includes a power supply, a monitoring component 6 and an industrial computer. The monitoring component 6 is used to collect current actual sea condition data and the current motion state of the main body 2. The industrial computer can receive the data collected by the monitoring component 6 and predict the motion state of the main body 2, and control the XY compensation mechanism 3 and the Z compensation mechanism 4 to perform motion compensation according to the predicted motion state.

[0066] The power supply can provide energy for the electrical devices in the compensation system. Exemplarily, the power supply can be a battery.

[0067] Exemplarily, the monitoring component 6 may include a water depth sensor, an MPU attitude sensor, a rotation speed sensor, a pressure sensor, etc., or other sensors in the prior art that can collect actual sea conditions data and the motion status of objects, which will not be repeated here.

[0068] Through the cooperation between the monitoring component 6 and the industrial computer, the AUV launching and retracting device 13 is controlled in real time and predictively, which effectively improves the accuracy and efficiency of the compensation, makes the AUV launching and retracting device 13 stabilize quickly, and improves the operating efficiency of the AUV12 deployment and recovery.

[0069] In some embodiments, see Figure 4 As shown, a hydraulic throttle valve (not shown) is provided between the connecting oil chamber 424 and the rod chamber 413 , and an exhaust throttle valve (not shown) is provided between the compensating air chamber 427 and the gas cylinder 43 .

[0070] By adjusting the hydraulic throttle valve, the damping characteristics of passive compensation can be changed. For example, in calmer sea conditions, the opening of the hydraulic throttle valve can be increased to reduce the damping, thereby allowing a certain range of heave movement; while in the case of larger waves, the opening of the hydraulic throttle valve can be reduced to increase the damping to more effectively absorb and buffer vibration energy.

[0071] By adjusting the exhaust throttle valve, the stiffness characteristics of passive compensation can be changed. For example, when the hydraulic cylinder 41 is subjected to a large load, the exhaust throttle valve opening can be increased to increase the stiffness, thereby enhancing the buffering effect; conversely, when the hydraulic cylinder 41 is subjected to a small load, the exhaust throttle valve opening can be reduced to reduce the system stiffness.

[0072] The Z-direction compensation mechanism 4 of the present invention can select appropriate stiffness and damping parameters by adjusting the hydraulic throttle valve and the exhaust throttle valve to better adapt to different application scenarios. It has better flexibility and adaptability and can achieve better compensation effects.

[0073] In some embodiments, see Figure 4 As shown, the hydraulic control assembly 44 includes a driving motor 442 and a bidirectional pump 441 for conveying hydraulic oil, and the bidirectional pump 441 is respectively connected to the first compensation oil chamber 425 and the second compensation oil chamber 426.

[0074] Specifically, when it is monitored that the AUV retracting and launching device 13 has a downward trend, the two-way pump 441 pumps the hydraulic oil inside the second compensation oil chamber 426 into the first compensation oil chamber 425 at high pressure; when it is monitored that the AUV retracting and launching device 13 has an upward trend, the two-way pump 441 pumps the hydraulic oil inside the first compensation oil chamber 425 into the second compensation oil chamber 426 at high pressure.

[0075] See also Figure 1 and Figure 5 As shown, the present invention provides a compensation method for a multi-degree-of-freedom motion compensation system for AUV retracting and launching operations, comprising:

[0076] S10. The main body 2 is installed between the crane and the AUV retracting device 13,

[0077] S20. Real-time collection of current sea conditions data and the current motion status of the subject 2,

[0078] S30. According to the collected current sea state data and the current motion state of the subject 2, the motion state of the subject 2 is predicted based on the very short-term prediction algorithm, for example, the motion state of the subject 2 in the next few seconds is predicted.

[0079] S40. Control the XY compensation mechanism 3 and the Z compensation mechanism 4 to perform motion compensation according to the predicted motion state.

[0080] By performing real-time and predictive motion compensation control on the AUV launching and retracting device 13, the accuracy and efficiency of the compensation are effectively improved, so that the AUV launching and retracting device 13 can be quickly stabilized, thereby improving the operational efficiency of the AUV 12 deployment and recovery.

[0081] In some embodiments, the compensation method includes:

[0082] During the deployment of the AUV 12 , the AUV 12 and the AUV launching and retracting device 13 are lowered to the target water depth. During the lowering process, the compensation system is controlled to continuously perform motion compensation on the AUV launching and retracting device 13 .

[0083] Specifically, during the deployment of the AUV 12, the crane slowly releases the cable to lower the AUV 12 and the AUV retracting and launching device 13 to the target water depth. During the lowering process, the XY compensation mechanism 3 and the Z compensation mechanism 4 are controlled to continuously perform motion compensation to ensure the stability of the AUV retracting and launching device 13 during the lowering process.

[0084] In some embodiments, the compensation method includes:

[0085] During the recovery process of AUV12, after AUV12 arrives near the AUV retracting device 13, the compensation system is controlled to perform motion compensation on the AUV retracting device 13 so that the AUV retracting device 13 is stabilized at a certain position underwater, and then the AUV12 and the AUV retracting device 13 are docked.

[0086] Specifically, during the recovery process of AUV12, the signal transmitter on the AUV launching and retracting device 13 sends a task instruction to AUV12. After completing the task, AUV12 autonomously navigates to the vicinity of the AUV launching and retracting device 13. After AUV12 arrives near the AUV launching and retracting device 13, it controls the XY compensation mechanism 3 and the Z compensation mechanism 4 to perform motion compensation to ensure the stability of the AUV launching and retracting device 13. After that, the optical device on the AUV launching and retracting device 13 identifies the specific position of AUV12 relative to the AUV launching and retracting device 13, and then autonomously plans a path to achieve the smooth docking of AUV12. After the docking is completed, AUV12 performs energy replenishment and data transmission through a preset interface. When it is necessary to recover AUV12, the crane system retracts the cable, lifts AUV12 and the AUV launching and retracting device 13 to the deck of the operating vessel 11, and completes the recovery.

[0087] In some embodiments, the compensation method includes:

[0088] The amount of oil in the first compensation oil chamber 425 and the second compensation oil chamber 426 is adjusted through the hydraulic control component 44 to adjust the compensation amount in the Z direction and change the proportion of active compensation in the entire Z-direction compensation mechanism 4, thereby achieving more efficient energy utilization and reducing unnecessary energy consumption while ensuring the heave compensation effect.

[0089] In the description of this specification, the description with reference to the terms "in some embodiments", "exemplary", "for example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0090] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the field can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.

Claims

1. A multi-degree-of-freedom motion compensation system for AUV retracting and launching operations, comprising a main body, characterized in that the main body comprises an XY compensation mechanism and a Z compensation mechanism, The XY compensation mechanism includes a plurality of thrusters, the thrust direction of which is arranged along the vertical direction of the Z direction. The Z-direction compensation mechanism includes a hydraulic cylinder, a composite accumulator and a gas cylinder. The hydraulic cylinder comprises a first piston member for hoisting the AUV storage and launching device, and the inner cavity of the hydraulic cylinder is divided into a vacuum rodless cavity and a rod cavity filled with hydraulic oil by the first piston member. The composite accumulator comprises a cavity, a fixed partition and a second piston member that can reciprocate relative to the fixed partition are arranged in the cavity, the second piston member comprises a first piston and a second piston that are connected to each other, the first piston and the second piston are respectively arranged on both sides of the fixed partition, the first piston, the fixed partition and the second piston divide the cavity into a connecting oil chamber, a first compensation oil chamber, a second compensation oil chamber and a compensation air chamber that are arranged in sequence, A connecting passage is provided between the connecting oil chamber and the rod chamber, and between the compensating air chamber and the gas cylinder. A hydraulic control component is provided between the first compensating oil chamber and the second compensating oil chamber, which can transport the hydraulic oil inside the two chambers back and forth in both directions to change the amount of oil inside the two chambers.

2. A multi-degree-of-freedom motion compensation system for AUV retrieval and deployment operations according to claim 1, characterized in that the first piston member is arranged on the center of gravity line of the main body.

3. A multi-degree-of-freedom motion compensation system for AUV launching and retracting operations according to claim 1, characterized in that the main body is provided with an integrated shell, the integrated shell is provided with an installation cavity, the XY compensation mechanism and the Z compensation mechanism are arranged in the installation cavity, the thruster at least partially extends from the installation cavity to the outside of the installation cavity, and the outer shell is provided with a telescopic opening for allowing the first piston member to be telescoped inside and outside the installation cavity.

4. A multi-degree-of-freedom motion compensation system for AUV retrieval and launching operations according to claim 3, characterized in that the shell includes a side wall enclosed by four side walls, the cross-section of the side wall in the vertical direction of the Z direction is a hollow rectangular structure, and a propeller is correspondingly arranged on each side wall, and the propellers of each propeller are symmetrically arranged in pairs.

5. A multi-degree-of-freedom motion compensation system for AUV launching and retracting operations according to claim 1, characterized in that it also includes a power supply, a monitoring component and an industrial computer, wherein the monitoring component is used to collect current actual sea condition data and the current motion state of the main body, and the industrial computer can receive the data collected by the monitoring component and predict the motion state of the main body, and control the XY compensation mechanism and the Z compensation mechanism to perform motion compensation according to the predicted motion state.

6. A multi-degree-of-freedom motion compensation system for AUV retraction and deployment operations according to claim 1, characterized in that a hydraulic throttle valve is provided between the connecting oil chamber and the rod chamber, and an exhaust throttle valve is provided between the compensation air chamber and the gas cylinder.

7. A multi-degree-of-freedom motion compensation system for AUV retracting and launching operations according to claim 1, characterized in that the hydraulic control component includes a drive motor and a bidirectional pump for conveying hydraulic oil, and the bidirectional pump is respectively connected to the first compensation oil chamber and the second compensation oil chamber.

8. A compensation method for a multi-degree-of-freedom motion compensation system for AUV launching and retracting operations according to any one of claims 1 to 7, characterized in that: include: The main body is installed between the crane and the AUV retracting and launching device. Real-time collection of current sea conditions data and the current subject's motion status, According to the collected current sea condition data and the current motion state of the subject, the motion state of the subject is predicted based on an extremely short-term prediction algorithm, The XY compensation mechanism and the Z compensation mechanism are controlled to perform motion compensation according to the predicted motion state.

9. The compensation method according to claim 8, characterized in that: include: During the AUV deployment process, the AUV and the AUV retracting and launching device are lowered to the target water depth, and during the lowering process, the compensation system is controlled to continuously perform motion compensation on the AUV retracting and launching device; During the AUV recovery process, after the AUV arrives near the AUV retracting and launching device, the compensation system is controlled to perform motion compensation on the AUV retracting and launching device, so that the AUV retracting and launching device is stabilized at a certain position underwater, and then the AUV and the AUV retracting and launching device are docked.

10. The compensation method according to claim 8, characterized in that: include: The oil volume in both the first compensation oil chamber and the second compensation oil chamber is adjusted by the hydraulic control component to adjust the compensation volume in the Z direction.

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