Autonomous Attitude Adjustment System and Method for Suspended Underwater Docking Platform

Abstract

This invention provides an autonomous attitude adjustment system and method for a suspended underwater docking platform, comprising: a buoyancy adjustment module, a power control module, a sensing module, and an attitude control module. The buoyancy adjustment module is installed on the docking platform and adjusts the buoyancy of the docking platform by filling and draining water. The power control module is connected to the buoyancy adjustment module and is used to control the filling and draining of the buoyancy adjustment module. The sensing module is used to collect attitude data of the docking platform and adjustment data of the buoyancy adjustment module, and the attitude control module interacts with the sensing module. The attitude control module controls the buoyancy adjustment module through the power control module based on the data collected by the sensing module. This invention utilizes a closed-loop feedback control system to change the drainage volume of each buoyancy adjustment device arranged on the platform according to the platform's attitude deviation, thereby balancing the platform's buoyancy and maintaining the optimal docking attitude to meet the docking mission requirements of single or multiple vehicles.

Description

Technical Field

[0001] This invention relates to the field of underwater unmanned docking technology for aircraft, specifically to an attitude autonomous adjustment system and method for a suspended underwater docking platform. Background Technology

[0002] With the continuous expansion of the depth and breadth of ocean development and utilization, autonomous underwater vehicles (AUVs) are widely used in various sea areas, representing a highly practical and promising type of unmanned marine navigation equipment. However, due to limitations such as limited travel distance and weak communication capabilities, these vehicles cannot perform long-term, continuous underwater operations, requiring repeated deployment and retrieval, resulting in low efficiency. To overcome these problems, the industry commonly employs underwater docking platforms to provide operational support for the vehicles, meeting their requirements for energy replenishment and data relay transmission.

[0003] To efficiently complete surveying and exploration tasks involving topography, geomorphology, or marine life over large areas of water, multiple underwater vehicles (UAVs) are often used simultaneously. Therefore, it is crucial to ensure adequate support for refueling and data relay across these multiple UAVs. However, single docking platforms have low docking efficiency, only able to meet the docking needs of a single UAV at a time, and cannot support efficient docking and recovery when multiple UAVs are operating simultaneously. Therefore, research has been conducted on underwater docking platforms that can provide docking support for multiple UAVs.

[0004] Common deployment methods for underwater docking platforms include floating deployment and bottom-mounted deployment. The former offers broader environmental adaptability and has lower requirements for seabed composition and topography. Floating deployment of underwater docking platforms provides a stable docking environment for vehicles, enabling them to efficiently charge and transmit data within the stable platform. It also reduces the possibility of accidental impact damage to exposed parts of the vehicle not connected to the docking device and minimizes the impact of ocean currents. The underwater docking platform's workflow involves significant movements such as pushing out and retracting the docking device, and retrieving the entire vehicle after successful docking. In a floating state, these pushing out and retracting movements cause changes in the platform's attitude, failing to meet docking requirements and reducing the success rate of docking missions. Furthermore, the harsh and complex underwater environment also affects the platform's attitude and stability.

[0005] A review of existing patents and literature reveals that current technologies for attitude adjustment of suspended docking platforms primarily target single docking devices, and those concerning underwater equipment and platforms mainly focus on attitude and buoyancy adjustment technologies for unmanned aerial vehicles (UAVs). No research has been found on autonomous attitude adjustment technologies for multi-UAV docking underwater platforms. Therefore, this invention, a system and method for autonomous attitude adjustment of suspended underwater docking platforms, is of great importance.

[0006] Patent document CN206914586U discloses an underwater device with adjustable buoyancy and attitude, including a main body and a sealing cylinder disposed beside the main body. The sealing cylinder has an opening and includes: a connecting plate dividing the sealing cylinder into two independent spaces; a push rod, the first end of which is connected to the connecting plate; a telescopic piston rod, the first end of which is connected to the second end of the push rod; and a piston connected to the second end of the telescopic piston rod. The piston, the connecting plate, and the sealing cylinder form a sealed cavity. However, the technical solution of this patent document differs from that of this application. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the purpose of this invention is to provide an autonomous attitude adjustment system and method for a suspended underwater docking platform.

[0008] The present invention provides an autonomous attitude adjustment system for a suspended underwater docking platform, comprising: a buoyancy adjustment module, a power control module, a sensing module, and an attitude control module;

[0009] The buoyancy adjustment module is installed on the docking platform, and the buoyancy adjustment module adjusts the buoyancy of the docking platform by filling and draining water;

[0010] The power control module is connected to the buoyancy adjustment module and is used to control the filling and draining of the buoyancy adjustment module;

[0011] The sensing module is used to collect attitude data of the docking platform and adjustment data of the buoyancy adjustment module, and the attitude control module interacts with the sensing module.

[0012] The attitude control module controls the buoyancy adjustment module through the power control module based on the data collected by the sensing module.

[0013] Preferably, the buoyancy adjustment module includes: a filling and draining mechanism, a piston cylinder, and a piston;

[0014] The piston cylinder and the filling and draining mechanism are arranged on the docking platform, the piston is arranged inside the piston cylinder, and the piston can move inside the piston cylinder;

[0015] The filling and draining mechanism is connected to the piston via telescopic outriggers and is used to drive the piston to move within the piston cylinder.

[0016] The sensing module is used to detect the displacement information of the telescopic outriggers on the filling and draining mechanism;

[0017] The buoyancy adjustment module is configured as a plurality of modules, which are respectively set at multiple azimuth angles of the docking platform.

[0018] Preferably, the sensing module includes: an attitude sensor and a displacement sensor;

[0019] The displacement sensor is installed on the filling and draining mechanism to collect the displacement data of the telescopic outriggers on the filling and draining mechanism, and transmits the data to the attitude control module as adjustment data.

[0020] The attitude sensor is installed at the geometric center of the docking platform to collect attitude data of the docking platform in real time and transmit the collected attitude data to the attitude control module.

[0021] Preferably, the power control module includes: a dry tank, a wet tank, and a compensation oil bladder;

[0022] The compensation oil bladder is connected to the wet tank and is used to supply oil to the wet tank; the wet tank is equipped with a hydraulic pump.

[0023] The dry compartment is connected to the wet compartment via a compartmentalized sealing partition, and a control valve assembly is installed inside the dry compartment;

[0024] The wet chamber is connected to the filling and draining mechanism through the control valve group. The attitude control module controls the opening and closing of the control valve group to realize the connection and disconnection between the wet chamber and the filling and draining mechanism.

[0025] Preferably, the dry chamber is equipped with hydraulic control devices and an AC drive motor;

[0026] The attitude control module sends control signals to the hydraulic controller, which in turn controls the AC drive motor, and the AC drive motor controls the opening and closing of the control valve group.

[0027] Preferably, the wet chamber is connected to the compensating oil bladder via an oil suction filter;

[0028] The control valve assembly is connected to the wet chamber via a high-pressure filter;

[0029] The dry compartment is equipped with electrical and oil interfaces.

[0030] Preferably, the docking platform includes: a main control cabin, a docking device, a push-out / return mechanism, a buoy, an anchor, an anchor cable, a main frame, and a platform frame;

[0031] The platform frame is mounted on the main frame, the buoyancy adjustment module is mounted on the main frame, and the power control module is mounted on the main frame.

[0032] The main control cabin, the docking device, and the float are mounted on the main frame, and the push-out / retract mechanism is connected to the docking device.

[0033] The anchor is connected to the main frame via the anchor cable.

[0034] This invention also provides a method for autonomous attitude adjustment of a suspended underwater docking platform, based on the above-mentioned autonomous attitude adjustment system for a suspended underwater docking platform, comprising the following steps:

[0035] Step S1: The attitude control module receives attitude data collected by the attitude sensor of the acquisition and sensing module in real time, and compares the received attitude data with the set attitude data. When the attitude deviation between the two does not meet the set requirements, the adjustment steps S2 and S3 are performed.

[0036] Step S2: The attitude data includes the pitch angle α and roll angle β of the docking platform. Based on the sign of the pitch angle α and roll angle β, the elevation of multiple azimuth angles of the docking platform is sorted. Based on the chasing leveling method, the piston cylinder that maintains a constant drainage volume is identified and used as the chasing target.

[0037] Step S3: The attitude control module analyzes the attitude deviation between each azimuth angle and the target being pursued. Based on the attitude deviation, it analyzes the filling and draining requirements of the piston cylinders at each azimuth angle and converts them into the displacement of the filling and draining mechanisms at each azimuth angle. The attitude control module transmits the command to the power control module, which further decomposes the command and controls the direction and opening of the electro-proportional directional valves of the control valves connected to each filling and draining mechanism in the control valve group. The telescopic outriggers drive the pistons to move up and down, adjusting the filling and draining of the piston cylinders at each azimuth angle, changing the draining volume, and adjusting the buoyancy of the platform at each azimuth angle.

[0038] Step S4: Repeat steps S1 to S3 to continuously reduce the attitude deviation until the attitude deviation between the collected attitude data and the set attitude data is within the set range, thereby achieving attitude adjustment.

[0039] Preferably, in step 2, the piston cylinder that maintains a constant drainage volume is determined as the chasing target based on the movement direction of the docking device;

[0040] When the docking device is inside the docking platform, the docking platform is in a balanced state;

[0041] When the docking device is pushed out of the docking platform by the push-out / retract mechanism, the docking platform tends to tilt forward, with the piston cylinder at its highest point as the target it is chasing.

[0042] When the docking device is retracted into the docking platform by the push-out / retract mechanism, the docking platform tends to tilt backward, using the piston cylinder at its lowest point as the target.

[0043] Preferably, the buoyancy adjustment modules are provided at the four azimuth angles of the docking platform;

[0044] The power control module changes the piston adjustment speed by altering the opening size of the electro-proportional directional valve of the filling and draining mechanism, and sets the piston speed h for each azimuth angle. i The rate of change and the hydraulic oil flow Q through the electro-proportional directional valve i Proportional:

[0045]

[0046] Where i = 1, 2, 3, 4; k i It is a proportionality coefficient related to the i-th filling and draining mechanism, reflecting the influence of flow rate on piston change rate per unit time;

[0047] Hydraulic oil flow rate Q i The opening degree u of the electro-proportional directional valve i The decision is based on the assumption that a linear relationship exists between the two:

[0048] Q i =c i u i

[0049] Among them, c i It is the proportional coefficient related to the characteristics of the i-th electro-proportional directional valve. In summary, the piston h can be obtained. i The relationship between the rate of change and the opening degree of the electro-proportional directional valve:

[0050]

[0051] Piston h i Displacement H i With buoyancy F i The relationship between them is linear, expressed as:

[0052] F i =εH i

[0053] Wherein, ε is the proportionality coefficient related to buoyancy of the docking platform;

[0054] The required buoyancy F is calculated based on the pitch angle α and roll angle β of the docking platform's current attitude. i Determine the opening degree u of each electro-proportional directional valve. i An adaptive control algorithm is used to adjust the dynamic characteristics of the system in real time. The specific expression is as follows:

[0055] F f1 +F f2 +F f3 +Ff4 =W+T

[0056] F f1 y1+F f2 y2+F f3 y3+F f4 y4 = 0

[0057] F f1 x1+F f2 x2+F f3 x3+F f4 x4 = 0

[0058]

[0059] e x =α-α target

[0060] e y =β-β target

[0061]

[0062] Where W represents the underwater net weight of the docking platform, and L... x L y Here, k and λ represent the platform's length and width, respectively; k and λ are adaptive parameters; ΔU is the control law; and e is the attitude error. It is the rate of change of error, F f1 F f2 F f3 F f4 The buoyancy change provided by the buoyancy adjustment modules at various azimuth angles, T is the vertical component of the tension of the anchor cable on the docking platform, y1, y2, y3, y4, x1, x2, x3, and x4 represent the X-axis and Y-axis distances of each of the filling and draining mechanisms from the geometric center point of the docking platform, respectively, and α target β target α and β represent the target values ​​of pitch angle α and roll angle β, respectively, while ex and ey represent the differences between the real-time values ​​of pitch angle α and roll angle β and the target values, respectively.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] 1. The underwater docking platform attitude autonomous adjustment system of the present invention has the functions of buoyancy adjustment and coordinated control of docking actuator. By establishing a mathematical model of the piston displacement change rate and the opening degree of the electro-proportional directional valve corresponding to the buoyancy adjustment module, the relationship between the displacement of each piston and the buoyancy is determined. The required buoyancy is calculated according to the horizontal attitude of the platform, and then the opening degree of each electro-proportional directional valve is determined. Furthermore, the adaptive control algorithm is used to realize the autonomous adjustment of buoyancy, thereby controlling the platform to maintain the desired attitude.

[0065] 2. The underwater docking platform attitude autonomous adjustment system of the present invention is a modular design, which has the characteristics of good flexibility, strong scalability and easy maintenance. Since the buoyancy adjustment module only needs to be flexibly connected to the power control module, the number and layout can be flexibly configured according to the operating characteristics of the underwater docking platform to change the buoyancy distribution and buoyancy adjustment range of the platform.

[0066] 3. The buoyancy adjustment module of the present invention has a simple composition and no longer uses an oil bladder to change the drainage volume. It can avoid the influence of the uncertain deformation of the flexible oil bladder on the buoyancy adjustment control in complex underwater environments. The piston cylinder size can be changed according to the buoyancy adjustment range requirements.

[0067] 4. The power control module of this invention adopts a hydraulic system and an integrated design, which is convenient for expansion and can effectively reduce the weight and size of the docking platform. Through the closed and pressure compensation design, there is no exchange of substances with the outside world, which improves the corrosion and pollution resistance and achieves reliable protection for non-pressure resistant components, making it suitable for deep-sea underwater operation environments.

[0068] 5. The present invention has wide applicability. The autonomous adjustment system and method are not only applicable to docking platforms for single or multiple vehicles, but also to the attitude adjustment of other suspended underwater work platforms. It can meet the attitude requirements of the onboard equipment or the platform as a whole. At the same time, it can meet the overall buoyancy adjustment of the platform within a certain range, improve the platform's adaptability to the underwater environment, and has strong anti-interference ability. Attached Figure Description

[0069] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0070] Figure 1 This invention relates to a schematic diagram of an underwater docking platform attitude autonomous adjustment system.

[0071] Figure 2 This is a schematic diagram of the buoyancy adjustment module involved in the present invention.

[0072] Figure 3 This is a schematic diagram of the power control module involved in the present invention.

[0073] Figure 4 This is a schematic diagram of the docking device of the suspended underwater docking platform of the present invention retracting into the platform.

[0074] Figure 5 This is a schematic diagram of the attitude change caused by the docking device of the suspended underwater docking platform that is involved in this invention when it is pushed out of the platform.

[0075] Figure 6 This invention relates to a schematic diagram of the azimuth sequence of the underwater docking platform.

[0076] Figure 7 This is a flowchart illustrating the logic of how the present invention enables autonomous attitude adjustment and buoyancy adjustment.

[0077] Figure 8 This is a schematic diagram of the hydraulic system involved in this invention.

[0078] The diagram shows:

[0079] Buoyancy adjustment module 1 Compensation oil bladder 17

[0080] Power control module 2, compartment sealing bulkhead 18

[0081] Sensing Module 3 Hydraulic Control Device 19

[0082] Attitude control module 4, AC drive motor 20

[0083] Main frame 5, high-pressure filter 21

[0084] Main control compartment 6, control valve group 22

[0085] 7 Inflation and drainage mechanism; 23 Hydraulic pump

[0086] Piston cylinder 8, oil suction filter 24

[0087] Piston 9 Electrical Interface 25

[0088] Platform framework 10, oil circuit interface 26

[0089] Telescopic outrigger 11, docking device 27

[0090] Attitude sensor 12, float 28

[0091] Displacement sensor 13 Anchor 29

[0092] 14 push / return mechanisms and 30 anchor cables

[0093] Dry compartment 15, aircraft 31

[0094] Wet Chamber 16 Detailed Implementation

[0095] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0096] Example 1:

[0097] like Figure 1-8As shown, this embodiment provides an autonomous attitude adjustment system for a suspended underwater docking platform, including: a buoyancy adjustment module 1, a power control module 2, a sensing module 3, and an attitude control module 4; the buoyancy adjustment module 1 is installed on the docking platform, and adjusts the buoyancy of the docking platform by filling and draining water; the power control module 2 is connected to the buoyancy adjustment module 1 and is used to control the filling and draining of the buoyancy adjustment module 1; the sensing module 3 is used to collect the attitude data of the docking platform and the adjustment data of the buoyancy adjustment module 1, and the attitude control module 4 interacts with the sensing module 3; the attitude control module 4 controls the buoyancy adjustment module 1 through the power control module 2 based on the data collected by the sensing module 3.

[0098] The docking platform includes: a main control compartment 6, a docking device 27, a push-out / retract mechanism 14, a float 28, an anchor 29, an anchor cable 30, a main frame 5, and a platform frame 10; the platform frame 10 is mounted on the main frame 5, the buoyancy adjustment module 1 is mounted on the main frame 5, and the power control module 2 is mounted on the main frame 5; the main control compartment 6, the docking device 27, and the float 28 are mounted on the main frame 5, and the push-out / retract mechanism 14 is connected to the docking device 27; the anchor 29 is connected to the main frame 5 via the anchor cable 30.

[0099] The sensing module 3 includes an attitude sensor 12 and a displacement sensor 13. The displacement sensor 13 is installed on the filling and draining mechanism 7 and is used to collect the displacement data of the telescopic outrigger 11 on the filling and draining mechanism 7 and transmit it to the attitude control module 4 as adjustment data. The attitude sensor 12 is installed at the geometric center of the docking platform and is used to collect the attitude data of the docking platform in real time and transmit the collected attitude data to the attitude control module 4.

[0100] The buoyancy adjustment module 1 includes: an inflation / deflation mechanism 7, a piston cylinder 8, and a piston 9; the piston cylinder 8 and the inflation / deflation mechanism 7 are disposed on the docking platform, the piston 9 is disposed inside the piston cylinder 8, and the piston 9 can move inside the piston cylinder 8; the inflation / deflation mechanism 7 is driven to the piston 9 via a telescopic support leg 11, which is used to drive the piston 9 to move inside the piston cylinder 8; the sensing module 3 is used to detect the displacement information of the telescopic support leg 11 on the inflation / deflation mechanism 7; multiple buoyancy adjustment modules 1 are configured, and the multiple buoyancy adjustment modules 1 are respectively disposed at multiple azimuth angles of the docking platform.

[0101] The power control module 2 includes a dry compartment 15, a wet compartment 16, and a compensation oil bladder 17. The compensation oil bladder 17 is connected to the wet compartment 16 and is used to supply oil to the wet compartment 16. The wet compartment 16 is equipped with a hydraulic pump 23. The dry compartment 15 is connected to the wet compartment 16 through a compartmentalized sealing partition 18, and a control valve assembly 22 is installed inside the dry compartment 15. The wet compartment 16 is connected to the filling and draining mechanism 7 through the control valve assembly 22. The attitude control module 4 controls the opening and closing of the control valve assembly 22 to realize the connection and disconnection between the wet compartment 16 and the filling and draining mechanism 7. The dry compartment 15 is equipped with a hydraulic controller 19 and an AC drive motor 20. The attitude control module 4 sends control signals to the hydraulic controller 19, which controls the AC drive motor 20, and the AC drive motor 20 controls the opening and closing of the control valve assembly 22. The wet tank 16 is connected to the compensating oil bladder 17 via the suction oil filter 24; the control valve group 22 is connected to the wet tank 16 via the high pressure filter 21; the dry tank 15 is equipped with an electrical interface 25 and an oil circuit interface 26.

[0102] This embodiment also provides a method for autonomous attitude adjustment of a suspended underwater docking platform, based on the above-mentioned autonomous attitude adjustment system for a suspended underwater docking platform, including the following steps:

[0103] Step S1: The attitude control module 4 receives the attitude data collected by the attitude sensor 12 of the acquisition and sensing module 3 in real time, and compares the received attitude data with the set attitude data. When the attitude deviation between the two does not meet the set requirements, the adjustment steps S2 and S3 are performed.

[0104] Step S2: The attitude data includes the pitch angle α and roll angle β of the docking platform. Based on the sign of the pitch angle α and roll angle β, the elevation of multiple azimuth angles of the docking platform is sorted. Based on the chasing leveling method, the piston cylinder 8 that maintains a constant drainage volume is identified and used as the chasing target.

[0105] Based on the direction of movement of the docking device 27, the piston cylinder 8, which maintains a constant drainage volume, is identified as the target to be pursued.

[0106] When the docking device 27 is inside the docking platform, the docking platform is in a balanced state;

[0107] When the docking device 27 is pushed out of the docking platform by the push-out / retract mechanism 4, the docking platform tends to tilt forward, with the piston cylinder 8 at the highest point as the target to chase;

[0108] When the docking device 27 is retracted into the docking platform by the push-out / retract mechanism 4, the docking platform tends to tilt backward, with the piston cylinder 8 at its lowest point as the target to chase.

[0109] After identifying the piston cylinder 8 as the target to be pursued, the attitude of the docking platform is adjusted by adjusting the buoyancy of the remaining piston cylinders 8 at their respective locations through the filling and draining mechanisms 7 connected to each of the other piston cylinders 8.

[0110] Step S3: The attitude control module 4 analyzes the attitude deviation between each azimuth angle and the target being pursued. Based on the attitude deviation, the filling and draining requirements of the piston cylinder 8 at each azimuth angle are analyzed and converted into the displacement of the filling and draining mechanism 7 at each azimuth angle. The attitude control module 4 transmits the command to the power control module 2. The power control module 2 further decomposes the command and controls the direction and opening of the electro-proportional directional valves of the control valves connected to each filling and draining mechanism 7 in the control valve group. The piston 9 is driven up and down by the telescopic outrigger 11 to adjust the filling and draining of the piston cylinder 8 at each azimuth angle, change the draining volume, and adjust the buoyancy of the platform at each azimuth angle.

[0111] Step S4: Repeat steps S1 to S3 to continuously reduce the attitude deviation until the attitude deviation between the collected attitude data and the set attitude data is within the set range, thereby achieving attitude adjustment.

[0112] Buoyancy adjustment modules 1 are installed at the four azimuth angles of the docking platform;

[0113] The power control module 2 changes the piston adjustment speed by altering the opening size of the electro-proportional directional valve of the filling and draining mechanism 7, and sets the piston speed h for each azimuth angle. i The rate of change and the hydraulic oil flow Q through the electro-proportional directional valve i Proportional:

[0114]

[0115] Where i = 1, 2, 3, 4; k i It is a proportionality coefficient related to the i-th filling and draining mechanism 7, reflecting the influence of the flow rate on the piston change rate per unit time;

[0116] Hydraulic oil flow rate Q i The opening degree u of the electro-proportional directional valve i The decision is based on the assumption that a linear relationship exists between the two:

[0117] Q i =c i u i

[0118] Among them, c i It is the proportional coefficient related to the characteristics of the i-th electro-proportional directional valve. In summary, the piston h can be obtained. i The relationship between the rate of change and the opening degree of the electro-proportional directional valve:

[0119]

[0120] Piston h i Displacement H i With buoyancy F i The relationship between them is linear, expressed as:

[0121] F i =εH i

[0122] Wherein, ε is the proportionality coefficient related to buoyancy of the docking platform;

[0123] The required buoyancy F is calculated based on the pitch angle α and roll angle β of the docking platform's current attitude. i Determine the opening degree u of each electro-proportional directional valve. i An adaptive control algorithm is used to adjust the dynamic characteristics of the system in real time. The specific expression is as follows:

[0124] F f1 +F f2 +F f3 +F f4 =W+T

[0125] F f1 y1+F f2 y2+F f3 y3+F f4 y4 = 0

[0126] F f1 x1+F f2 x2+F f3 x3+F f4 x4 = 0

[0127]

[0128] e x =α-α target

[0129] e y =β-β target

[0130]

[0131] Where W represents the underwater net weight of the docking platform, and L... x L y Here, k and λ represent the platform's length and width, respectively; k and λ are adaptive parameters; ΔU is the control law; and e is the attitude error. It is the rate of change of error, F f1 F f2 F f3 F f4The buoyancy adjustment module 1 provides buoyancy changes for each azimuth angle; T is the vertical component of the tension of the anchor cable 30 on the docking platform; y1, y2, y3, y4, x1, x2, x3, and x4 represent the distances between each filling / draining mechanism and the geometric center point of the docking platform along the X and Y axes, respectively; α target β target α and β represent the target values ​​of pitch angle α and roll angle β, respectively. ex and ey represent the differences between the real-time values ​​of pitch angle α and roll angle β and the target values, respectively, i.e., attitude errors.

[0132] To address the issue of attitude adjustment for underwater docking platforms in a suspended state, especially when multiple vehicles are docking, during operational tasks or in harsh underwater environments, this embodiment provides an autonomous attitude adjustment system and method for suspended underwater docking platforms. Through buoyancy control, the attitude of the suspended underwater docking platform is controlled. Specifically, a closed-loop feedback control system is used to adjust the displacement volume of each buoyancy adjustment device on the platform based on attitude deviations, balancing buoyancy to maintain the optimal docking attitude. This meets the docking requirements of single or multiple vehicles and can also be applied to the attitude adjustment of other suspended underwater work platforms to meet their operational attitude requirements. It offers good flexibility and wide applicability.

[0133] The adjustment system in this embodiment is highly flexible. The autonomous adjustment system and method are modularly designed, and the buoyancy adjustment module can be arranged at various points on the platform according to the changes in the platform's attitude before and after operation. It only needs to be connected to the power control module through pipelines to adjust the buoyancy distribution of the platform, allowing for flexible layout. Furthermore, the buoyancy adjustment module no longer uses an oil bladder to change the drainage volume, but directly relies on the reciprocating motion of the piston to change the system's drainage volume, which can avoid the impact of the uncertain deformation of the flexible oil bladder in complex underwater environments on the buoyancy adjustment control.

[0134] The adjustment system in this embodiment is highly compact, and the power control module can meet the needs of underwater working platforms with distributed and multi-drive characteristics, improving the platform's compactness. Through a fully enclosed integrated design, it has advantages such as corrosion resistance and system pressure compensation, and strong environmental adaptability.

[0135] Example 2:

[0136] Those skilled in the art can understand this embodiment as a more specific description of Embodiment 1.

[0137] This embodiment provides an autonomous attitude adjustment system for a suspended underwater docking platform, including a buoyancy adjustment module, a power control module, a sensing module, and an attitude control module.

[0138] The buoyancy adjustment module includes an inflation / deflation mechanism, a piston cylinder, and a piston. The piston cylinder is fixedly installed above the platform. The number, size, and installation position of the piston cylinders are determined based on the docking platform's dimensions, layout, and buoyancy adjustment range. Generally, they are arranged at the four corners of the platform, with at least four. Additional piston cylinders are added to consider the docking platform's attitude stability and to increase the system's maximum adjustment capacity. The inflation / deflation mechanism is installed on one side of the piston cylinder and rigidly connected to the piston. The piston and piston cylinder circumferential surfaces are reliably sealed. Driven by the inflation / deflation mechanism, the piston can slide back and forth within the piston cylinder, changing the deflation volume. When the actuator extends, moving closer to the piston cylinder's outlet side, the deflation volume increases, increasing buoyancy; conversely, the deflation volume decreases, decreasing buoyancy. This allows adjustment of the buoyancy at the location of the buoyancy adjustment module on the docking platform, enabling changes in the overall center of buoyancy in space. This adapts to changes in the center of gravity when the docking platform pushes out / retracts the docking device, thereby adjusting the platform's attitude. When the underwater environment changes or disturbances increase, the buoyancy adjustment module further improves the platform's resistance to currents by increasing the overall buoyancy of the platform.

[0139] The power control module includes a hydraulic pump, filter, control valve group, pressure compensation device, pressure sensor, etc., serving as the system's power source. It controls the direction and magnitude of the filling and draining mechanisms, adjusts the drainage volume of various buoyancy adjustment modules, and changes the buoyancy. The power control module also meets the distributed, multi-drive requirements of multi-vehicle docking underwater platforms. Adopting a hydraulic system and integrated design, the module is easily expandable and effectively reduces the weight and size of the docking platform. It provides a power source for the buoyancy adjustment modules and other functional actuators of the multi-vehicle docking underwater platform, enabling buoyancy adjustment and the linkage capability of distributed actuators, and providing collaborative control of multiple actuators. Through a closed-loop and pressure-compensated design, the module has no material exchange with the external environment, improving corrosion and contamination resistance, providing reliable protection for non-pressure-resistant components, and adapting to deep-sea operating environments.

[0140] The sensing module includes an attitude sensor and displacement sensors for each filling and draining mechanism. The attitude sensor is installed at the geometric center of the platform to collect platform attitude information in real time and use it as monitoring and control parameters for the attitude control module feedback system. The displacement sensors for each actuator are installed on the telescopic outriggers of the actuator. The drainage volume of each buoyancy adjustment module is obtained based on the specific values ​​of the displacement sensors, which is beneficial for buoyancy adjustment and control.

[0141] The attitude control module is either separately packaged or integrated into the main control compartment of the underwater docking platform. It interacts with the sensing module to collect platform attitude information in real time. Connected to the power control module, and using an adaptive control algorithm, it determines a fixed point as the "chasing" target based on attitude data deviations and the displacement strokes of each inflation / deflation mechanism. Maintaining the target constant, the module uses closed-loop feedback control to control the inflation / deflation mechanism's actions, continuously reducing attitude deviations and achieving attitude adjustment. Specifically, the attitude control module analyzes the elevation order of the platform in various directions based on the pitch angle α and roll angle β provided by the attitude sensors. Combined with the actions of the push / retract device, it determines the chasing target point. The volume of water discharged from the piston cylinder at the target point remains constant, i.e., the buoyancy remains constant. The module analyzes and calculates the buoyancy adjustment strategies for other piston cylinders in the buoyancy adjustment module, issuing adjustment commands to the power control module. This changes the direction and opening of the electro-proportional directional valves corresponding to each inflation / deflation mechanism, further adjusting the hydraulic oil flow to adjust the piston position in the piston cylinder, thus inflating and deflating the platform. By continuously adjusting the volume of water discharged from other piston cylinders, the buoyancy is changed, balancing the buoyancy of different parts of the platform and autonomously adjusting the platform's attitude.

[0142] This embodiment provides an autonomous attitude adjustment system for a suspended underwater docking platform, and also proposes an autonomous adjustment method. This method can be applied to other underwater suspended working platforms, and autonomously adjusting the platform's attitude can improve the measurement accuracy of instruments and equipment mounted on the platform.

[0143] This embodiment brings the following beneficial effects:

[0144] a. Wide applicability: The autonomous adjustment system and method described in this embodiment are not only applicable to docking platforms for single or multiple vehicles, but also to the attitude adjustment of other suspended underwater work platforms, meeting the attitude requirements of the onboard equipment or the platform as a whole. Simultaneously, it is used to meet the overall buoyancy adjustment of the platform within a certain range, improving the platform's adaptability to the underwater environment and enhancing its anti-interference capabilities.

[0145] b. High flexibility: The self-adjustment system and method in this embodiment are modularly designed. The buoyancy adjustment module can be arranged at various points on the platform according to the changes in the platform's attitude before and after operation. It only needs to be connected to the power control module through pipelines to adjust the buoyancy distribution of the platform, allowing for flexible layout. Furthermore, the buoyancy adjustment module no longer uses an oil bladder to change the drainage volume, but directly relies on the reciprocating motion of the piston to change the system's drainage volume. This avoids the impact of uncertain deformation of the flexible oil bladder in complex underwater environments on buoyancy adjustment and control.

[0146] c. High compactness: The power control module described in this embodiment can meet the needs of underwater working platforms with distributed and multi-drive characteristics, improve the compactness of the platform, and has advantages such as corrosion resistance and system pressure compensation through a fully enclosed integrated design, and has strong environmental adaptability.

[0147] Example 3:

[0148] Those skilled in the art can understand this embodiment as a more specific description of Embodiment 1.

[0149] This embodiment takes a docking platform with two docking devices as an example to provide a detailed description of a floating underwater docking platform attitude autonomous adjustment system and method.

[0150] like Figure 1 ,like Figure 2 As shown, the system mainly includes a buoyancy adjustment module 1, a power control module 2, a sensing module 3, and an attitude control module 4, all arranged within the main frame 5 of the docking platform. The attitude control module 4 is integrated into the main control compartment 6 of the docking platform. The main control compartment 6 is fixedly installed in the lower front part of the middle of the platform, receiving mission instructions from higher authorities and simultaneously issuing action commands to the various actuators of the power control module 2. The buoyancy adjustment module 1 includes a filling / draining mechanism 7, a piston cylinder 8, and a piston 9. The piston cylinder 8 is installed at the four upper corners of the docking platform and is fixedly mounted on the platform frame 10. The filling / draining mechanism 7 is vertically fixedly installed on the platform frame 10 at the bottom of the platform. The telescopic outriggers 11 of the filling / draining mechanism 7 are rigidly connected to the piston 9. The telescopic outriggers 11 extend and retract, causing the piston 9 to move up and down along the piston cylinder wall, changing the drainage volume of the piston cylinder 8 and thus altering the buoyancy provided at the piston cylinder 8. The sensing module 3 includes an attitude sensor 12 arranged at the geometric center of the platform. The attitude sensor 12 is a MEMS inertial navigation system used to monitor and feedback the attitude information of the platform, and a displacement sensor 13 installed on the filling and draining mechanism 7, which can obtain the drainage volume of the piston cylinder based on the displacement sensor value.

[0151] like Figure 3As shown, the power control module 2 is an integrated dry and wet chamber design, serving as the power source for the docking platform and autonomous adjustment system. It provides power to various actuators, including the filling and draining mechanism 7 and the docking platform's docking-enabled actuators such as the push-out / retraction mechanism 14. It is installed directly behind the main control compartment 6. The power control module 2 mainly consists of a dry chamber 15, a wet chamber 16, and a compensating oil bladder 17. The dry chamber 15 and the wet chamber 16 are separated by a compartmentalized sealing partition 18. The dry chamber 15 contains atmospheric pressure air and is equipped with hydraulic control devices 19, an AC drive motor 20, a high-pressure filter 21, a control valve group 22, and pressure sensors. The wet chamber 16 also serves as an oil tank, filled with hydraulic oil and equipped with a hydraulic pump 23, an oil suction filter 24, a temperature sensor, and a level gauge. The compensating oil bladder 17 is directly connected to the wet chamber 16, allowing the wet chamber 16 to maintain internal and external pressure balance, adapting to deep-sea operating environments, and also serving as a source of replenishment for the oil in the tank. The dry compartment 15 has an electrical interface 25 and an oil circuit interface 26 arranged on one side end cover. The electrical interface 25 mainly includes an AC power supply interface for the motor, a DC power supply interface for the valve group and sensors, and a control signal interface; the oil circuit interface 26 mainly includes two interfaces for the filling and draining mechanism 7 and other distributed drive actuators of the docking platform, all of which use quick connectors for easy disassembly and assembly.

[0152] like Figure 4 As shown, the underwater docking platform in this embodiment includes a main control cabin 6, two docking devices 27, two push-out / retract mechanisms 14, floats 28, anchors 29, anchor cables 30, a main frame 5, and a platform frame 10. The docking devices 27 are distributed on both sides of the platform near the top and are rigidly connected to the push-out / retract mechanisms 14. Through the reciprocating linear motion of the push-out / retract mechanisms 14, they move in and out of the docking platform. When the docking devices 27 push out of the platform, they perform the docking task for the vehicle; when they retract, they charge the vehicle and transmit data. The floats 28 are used to balance the platform's buoyancy. The anchors 29 and anchor cables 30 are used for anchoring and securing the platform underwater. The main frame 5 and platform frame 10 serve as structural supports for the docking platform and as mounting frames for other components.

[0153] Figure 4 As shown, the docking device on the right side of the docking platform has completed the docking task, and the spacecraft 31 is in a charging and / or data transmission state, while the docking device on the left side is still waiting for a docking task. After receiving the docking task, the extension / retraction mechanism 14 actuates, extending the docking device 27 out of the docking platform. This process will cause the platform attitude to tilt, such as... Figure 5 As shown. At this time, the MEMS inertial navigation system transmits the attitude data to the attitude control module 4, and the attitude control module 4 autonomously adjusts the platform attitude according to the attitude deviation.

[0154] Assuming the docking platform's left front is orientation 1, right front is orientation 2, left rear is orientation 3, and right rear is orientation 4, then... Figure 6 As shown, initially, the pistons 9 in the piston cylinders 8 at all four positions are in the middle position inside the piston cylinder 8, which serves as the drainage volume when the platform is launched into the water. The specific process of autonomous attitude adjustment is as follows:

[0155] Step 1: The attitude control module 4 collects the MEMS inertial navigation data from the sensing module 3 in real time and compares it with the set attitude data. When the attitude deviation is found to be inconsistent with the set requirements, the autonomous adjustment program is started.

[0156] Step 2: Sort the elevation of platforms 1, 2, 3, and 4 according to the sign of pitch angle α and roll angle β. At the same time, combine the action of the push / retract mechanism 14 to determine the piston cylinder 8 that keeps the drainage volume constant and take it as the pursuit target.

[0157] The "chasing" leveling method is adopted. When the docking device 27 is being pushed out, the highest point piston cylinder 8 is the chasing target. When the docking device 27 is being retracted, the lowest point piston cylinder 8 is the chasing target, so as to keep its drainage volume unchanged.

[0158] Based on the movement direction of the docking device 27, the piston cylinder 8, which maintains a constant drainage volume, is identified as the target being pursued. It can be seen that when the docking device 27 is inside the platform, the platform is in a balanced state. When the docking device 27 is pushed out by the push / retract mechanism 14, the platform tends to tilt forward, with the highest point as the target; when the docking device 27 is retracted by the push / retract mechanism 14, the platform tends to tilt backward, with the lowest point as the target. The remaining filling and draining mechanisms adjust the buoyancy of their respective positions to adjust the platform's attitude.

[0159] Step 3: Based on the deviation of each azimuth angle from the target being pursued, analyze the filling and draining requirements of the piston cylinders 8 in each azimuth angle, and convert them into the displacement of each filling and draining mechanism 7. Transmit the command to the power control module 2. The power control module 2 further decomposes the command and controls the direction and opening of the electro-proportional directional valves of each filling and draining mechanism 7. The telescopic outriggers 11 drive the pistons 9 to move up and down, adjust each piston cylinder 8 to fill and drain, change the drain volume, and adjust the buoyancy of each azimuth angle of the platform.

[0160] Furthermore, the power control module 2 changes the piston adjustment speed by altering the opening size of the electro-proportional directional valve of the filling and draining mechanism 7, and sets the piston speed h. i The rate of change of (i = 1, 2, 3, 4) and the hydraulic oil flow rate Q through the electro-proportional directional valve i Proportional:

[0161]

[0162] Where, k iIt is a proportionality coefficient related to the i-th filling and draining mechanism, reflecting the influence of flow rate on piston change rate per unit time.

[0163] Hydraulic oil flow rate Q i The opening degree u of the electro-proportional directional valve i The decision can be made by assuming a linear relationship between the two:

[0164] Q i =c i u i (2)

[0165] Among them, c i It is the proportional coefficient related to the characteristics of the i-th electro-proportional directional valve. In summary, the piston h can be obtained. i The relationship between the rate of change and the opening degree of the electro-proportional directional valve:

[0166]

[0167] Furthermore, piston h i Displacement H i With buoyancy F i The relationship between them is linear and can be expressed as:

[0168] F i =εH i (4)

[0169] Where ε is the proportionality coefficient of the platform related to buoyancy.

[0170] Step 4: Repeat steps 1 to 3 to continuously reduce the attitude deviation until the deviation between the collected attitude data and the set attitude is within the set range, thus achieving attitude adjustment. Specifically, the required buoyancy F can be calculated based on the platform's current attitude α and β. i This allows for the determination of the opening degree u of each electro-proportional directional valve. i To improve control performance, an adaptive control algorithm is used to adjust the dynamic characteristics of the system in real time to cope with uncertainties and changes. The specific expression is as follows:

[0171]

[0172] Where W is the platform's net underwater weight, L x L y Here, k and λ represent the platform's length and width, respectively; k and λ are adaptive parameters; ΔU is the control law; and e is the attitude error. It is the rate of change of error, F f1 F f2 F f3 F f4 The buoyancy change provided by each buoyancy adjustment module, where T is the vertical component of the anchor cable tension 30.

[0173] The aforementioned attitude autonomous adjustment process is also applicable to attitude change adjustments caused by changes in the external environment, and can also be used to adjust the overall buoyancy value of the docking platform to improve its anti-disturbance capability. The logic flowchart for implementing attitude autonomous adjustment and buoyancy adjustment in this embodiment is shown below. Figure 7 As shown.

[0174] The schematic diagram of the hydraulic system involved in this embodiment is as follows: Figure 8 As shown, the system employs a pressure compensation design. The elastic element compensates for the seawater pressure sensed by the oil bladder 17, transmitting it to the hydraulic system to ensure the return oil pressure equals the seawater pressure, automatically adjusting with seawater depth. This eliminates the influence of water pressure during the hydraulic cylinder operation of each actuator, reducing cylinder operating pressure and decreasing the power and volume of the entire power control module 2, making the entire power system simpler and lighter. A three-position four-way proportional directional valve is used to achieve the telescopic movement of each actuator. The valve core opening is driven by an input PWM signal, regulating the inlet and return oil flow rates, thereby controlling the operating speed of the mechanical actuator. The neutral position function uses a Y-type valve; when the three-position four-way proportional directional valve is in the neutral position, the inlet port P is closed, and the working ports A and B are connected to the return port T. The purpose of this locking circuit is to allow the hydraulic cylinder of the actuator to remain stationary at any position without shifting due to external forces. Furthermore, the Y-shaped center position mechanism allows for some floating in the hydraulic system, effectively mitigating the adverse effects of inertial loads generated during equipment operation. Finally, six sets of hydraulically controlled balance valves, each with interconnected control ports, form six hydraulic locks that maintain pressure at the entire actuator end.

[0175] The working process of this embodiment of a floating underwater docking platform attitude autonomous adjustment system and method is as follows:

[0176] The docking platform is suspended in an underwater environment at a certain depth via anchor 29 and anchor cable 30. The attitude control module 4 analyzes and calculates the change in the displacement volume of each piston cylinder 8 based on attitude feedback data, and issues adjustment commands through the power control module 2 to autonomously adjust the platform's attitude, allowing it to adapt to the surrounding water flow and maintain stability. The attitude control module 4 can synchronously adjust the displacement volume of each piston cylinder 8 according to the commands, increasing or decreasing the platform's total buoyancy.

[0177] When the platform receives one or more docking task commands, each push-out / retract mechanism 14 is activated. During the process of the docking device 27 extending from the platform, the attitude control module 4 determines the target to be pursued based on the attitude data deviation and the action commands of the push-out / retract mechanism 14, and transmits the buoyancy adjustment command to the power control module 2. The power control module 2 controls each control valve group according to the command, controls the operation of the filling and draining mechanism 7, adjusts the buoyancy distribution of the platform, balances the change of the platform's center of gravity, achieves autonomous adjustment of the platform, meets the docking requirements for the platform's attitude, and improves the docking success rate.

[0178] After the platform completes the docking task, the push-out / retraction mechanism 14 retracts the docking device 27 and the docked vehicle into the platform. This prevents the tail of the vehicle from being affected by accidental collisions or other environmental disturbances, maintains the stability of the platform in the water, and ensures that the successfully docked vehicle has more efficient charging and / or data transmission. The adjustment procedure is the same as above, and the attitude autonomous adjustment system autonomously adjusts the attitude of the platform to ensure its attitude stability.

[0179] The underwater docking platform's attitude autonomous adjustment system has buoyancy adjustment and docking actuator coordinated control functions. By establishing a mathematical model of the piston displacement change rate and the opening degree of the electro-proportional directional valve corresponding to the buoyancy adjustment module, the relationship between the displacement of each piston and buoyancy is determined. The required buoyancy is calculated based on the platform's horizontal attitude, and then the opening degree of each electro-proportional directional valve is determined. Furthermore, an adaptive control algorithm is used to realize the autonomous adjustment of buoyancy, thereby controlling the platform to maintain the desired attitude.

[0180] The underwater docking platform's attitude autonomous adjustment system features a modular design, offering high flexibility, scalability, and ease of maintenance. Since the buoyancy adjustment module is flexibly connected to the power control module, its quantity and layout can be flexibly configured according to the operational characteristics of the underwater docking platform, thereby altering the platform's buoyancy distribution and adjustment range.

[0181] The buoyancy adjustment module is simple in composition and no longer uses an oil bladder to change the drainage volume. This avoids the impact of the uncertain deformation of the flexible oil bladder in complex underwater environments on the buoyancy adjustment control. The piston cylinder size can be changed according to the buoyancy adjustment range requirements.

[0182] The power control module adopts a hydraulic system and an integrated design, which is convenient for expansion and can effectively reduce the weight and size of the docking platform. Through the closed and pressure compensation design, there is no exchange of substances with the outside world, which improves the corrosion and pollution resistance and provides reliable protection for non-pressure resistant components, making it suitable for deep-sea underwater operation environments.

[0183] In summary, the above are merely preferred embodiments of the present invention. Variations in the number of docking devices integrated into the underwater docking platform, the number of buoyancy adjustment modules, and their layout are all within the scope of protection of the present invention. Furthermore, the attitude autonomous adjustment system and method described in the present invention are also applicable to other underwater working platforms, and their application on relevant platforms should also fall within the scope of protection of the present invention.

[0184] This invention utilizes a closed-loop feedback control system to change the drainage volume of each buoyancy adjustment device arranged on the platform according to the platform attitude deviation, thereby balancing the platform buoyancy and maintaining the optimal docking attitude to meet the docking mission requirements of single or multiple vehicles.

[0185] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0186] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A floating underwater docking platform attitude autonomous adjustment system, characterized in that, include: Buoyancy adjustment module (1), power control module (2), sensing module (3) and attitude control module (4); The buoyancy adjustment module (1) is installed on the docking platform, and the buoyancy adjustment module (1) adjusts the buoyancy of the docking platform by filling and draining water; The power control module (2) is connected to the buoyancy adjustment module (1) and is used to control the filling and draining of the buoyancy adjustment module (1); The sensing module (3) is used to collect the attitude data of the docking platform and the adjustment data of the buoyancy adjustment module (1), and the attitude control module (4) interacts with the sensing module (3) for data exchange. The attitude control module (4) controls the buoyancy adjustment module (1) through the power control module (2) based on the data collected by the sensing module (3); The buoyancy adjustment module (1) includes: a filling and draining mechanism (7), a piston cylinder (8), and a piston (9); The piston cylinder (8) and the filling and draining mechanism (7) are arranged on the docking platform, the piston (9) is arranged inside the piston cylinder (8), and the piston (9) can move inside the piston cylinder (8); The filling and draining mechanism (7) is driven to the piston (9) via a telescopic support leg (11), and is used to drive the piston (9) to move inside the piston cylinder (8); The sensing module (3) is used to detect the displacement information of the telescopic support leg (11) on the filling and draining mechanism (7); The buoyancy adjustment module (1) is configured as a plurality of such modules, and the plurality of such buoyancy adjustment modules (1) are respectively set at multiple azimuth angles of the docking platform; The sensing module (3) includes: an attitude sensor (12) and a displacement sensor (13); The displacement sensor (13) is installed on the filling and draining mechanism (7) to collect the displacement data of the telescopic outrigger (11) on the filling and draining mechanism (7) and transmit it to the attitude control module (4) as an adjustment data. The attitude sensor (12) is installed at the geometric center of the docking platform to collect attitude data of the docking platform in real time and transmit the collected attitude data to the attitude control module (4). The power control module (2) includes: a dry tank (15), a wet tank (16), and a compensation oil bladder (17); The compensation oil bladder (17) is connected to the wet tank (16) and is used to supply oil to the wet tank (16); the wet tank (16) is equipped with a hydraulic pump (23); The dry compartment (15) is connected to the wet compartment (16) through a compartment sealing partition (18), and a control valve group (22) is provided inside the dry compartment (15); The wet chamber (16) is connected to the filling and draining mechanism (7) through the control valve group (22). The attitude control module (4) controls the opening and closing of the control valve group (22) to realize the connection and disconnection between the wet chamber (16) and the filling and draining mechanism (7).

2. The attitude autonomous adjustment system for the suspended underwater docking platform according to claim 1, characterized in that, The dry compartment (15) is equipped with a hydraulic control device (19) and an AC drive motor (20); The attitude control module (4) sends a control signal to the hydraulic control device (19), which controls the AC drive motor (20), and the AC drive motor (20) controls the opening and closing of the control valve group (22).

3. The attitude autonomous adjustment system for the suspended underwater docking platform according to claim 1, characterized in that, The wet chamber (16) is connected to the compensating oil bladder (17) via an oil suction filter (24); The control valve assembly (22) is connected to the wet chamber (16) via a high-pressure filter (21); the dry chamber (15) is provided with an electrical interface (25) and an oil circuit interface (26).

4. The attitude autonomous adjustment system for the suspended underwater docking platform according to claim 1, characterized in that, The docking platform includes: a main control cabin (6), a docking device (27), a push-out / return mechanism (14), a float (28), an anchor (29), an anchor cable (30), a main frame (5), and a platform frame (10); The platform frame (10) is mounted on the main frame (5), the buoyancy adjustment module (1) is mounted on the main frame (5), and the power control module (2) is mounted on the main frame (5). The main control cabin (6), the docking device (27) and the float (28) are mounted on the main frame (5), and the push-out / retract mechanism (14) is connected to the docking device (27); The anchor (29) is connected to the main frame (5) via the anchor cable (30).

5. A method for autonomous attitude adjustment of a suspended underwater docking platform, characterized in that, The attitude autonomous adjustment system for the suspended underwater docking platform according to claim 4 includes the following steps: Step S1: The posture control module (4) receives the posture data collected by the posture sensor (12) of the acquisition and sensing module (3) in real time, and compares the received posture data with the set posture data. When the posture deviation between the two does not meet the set requirements, the adjustment steps S2 and S3 are performed. Step S2: The attitude data includes the pitch angle α and roll angle β of the docking platform. Based on the sign of the pitch angle α and roll angle β, the elevation of multiple azimuth angles of the docking platform is sorted. Based on the chasing leveling method, the piston cylinder (8) that maintains a constant drainage volume is identified and used as the chasing target. Step S3: The attitude control module (4) analyzes the attitude deviation between each azimuth angle and the target being chased. Based on the attitude deviation, the filling and draining requirements of the piston cylinder (8) at each azimuth angle are analyzed and converted into the displacement of the filling and draining mechanism (7) at each azimuth angle. The attitude control module (4) transmits the command to the power control module (2). The power control module (2) further decomposes the command and controls the direction and opening of the electro-proportional directional valve of the control valve connected to each filling and draining mechanism (7) in the control valve group. The piston (9) is driven to move up and down by the telescopic outrigger (11) to adjust the piston cylinder (8) at each azimuth angle for filling and draining, change the drain volume, and adjust the buoyancy of the platform at each azimuth angle. Step S4: Repeat steps S1 to S3 to continuously reduce the attitude deviation until the attitude deviation between the collected attitude data and the set attitude data is within the set range, thereby achieving attitude adjustment.

6. The method for autonomous attitude adjustment of a suspended underwater docking platform according to claim 5, characterized in that, In step 2, the piston cylinder (8) that maintains a constant drainage volume is determined as the target to be chased, based on the movement direction of the docking device (27). When the docking device (27) is inside the docking platform, the docking platform is in a balanced state; When the docking device (27) is pushed out of the docking platform by the push-out / retract mechanism (14), the docking platform tends to tilt forward, with the piston cylinder (8) at the highest point as the target to chase; When the docking device (27) is retracted into the docking platform by the push-out / retract mechanism (14), the docking platform tends to tilt backward, with the piston cylinder (8) at its lowest point as the target.

7. The method for autonomous attitude adjustment of a suspended underwater docking platform according to claim 5, characterized in that, The buoyancy adjustment module (1) is installed at the four azimuth angles of the docking platform; The power control module (2) changes the piston adjustment by changing the opening size of the proportional directional valve of the filling and draining mechanism (7). Speed, the rate of change of piston hi at each azimuth angle is set and the hydraulic oil flow Q through the electro-proportional directional valve is adjusted. i Proportional: Where i = 1, 2, 3, 4; ki is the proportional coefficient related to the i-th filling and draining mechanism (7), reflecting the influence of flow rate on piston change rate per unit time; The hydraulic oil flow rate Qi is determined by the opening degree ui of the electro-proportional directional valve, assuming a linear relationship between the two: Q=c i u i Among them, c i It is the proportional coefficient related to the characteristics of the i-th electro-proportional directional valve. In summary, the piston h can be obtained. i change The relationship between the ratio and the opening degree of the electro-proportional directional valve: Piston h i Displacement H i With buoyancy F i The relationship between them is linear, expressed as: F i =e H i Wherein, ε is the proportionality coefficient related to buoyancy of the docking platform; Calculate the required buoyancy Fi based on the pitch angle α and roll angle β of the docking platform's current attitude, and determine the opening degree u of each electro-proportional directional valve. i An adaptive control algorithm is used to adjust the dynamic characteristics of the system in real time. The specific expression is as follows: F f1 +F f2 +F f3 +F f4 =W+T ff1 y1+F f2 y2+F f3 y3+F f4 y4=0 F f1 x1+F f2 x2+F f3 x3+F f4 x4=0 e x ＝α-α target e y ＝β-β target Where W is the underwater net weight of the docking platform, Lx and Ly are the length and width of the platform, respectively, k and λ are adaptive parameters, ΔU is the control law, and e is the attitude error. It is the rate of change of error, F f1 F f2 F f3 F f4 The buoyancy change provided by the buoyancy adjustment module (1) for each azimuth angle, T is the vertical component of the tension of the anchor cable (30) on the docking platform, and y1, y2, y3, y4, x1, x2, x3, and x4 represent the distances between each of the filling and draining mechanisms and the geometric center point of the docking platform along the X and Y axes, respectively. α target β target α and β represent the target values ​​of pitch angle α and roll angle β, respectively, while ex and ey represent the differences between the real-time values ​​of pitch angle α and roll angle β and the target values, respectively.

Images