A passive-active compound heave compensation system

Abstract

The present application relates to mixed heave compensation technical field, specifically disclose a kind of active and passive compound heave compensation system, including active heave compensation subsystem and passive heave compensation subsystem, winch motion control module built-in switchable execution speed priority mode, torque priority mode and safety takeover mode, in speed priority mode, winch motor uses the double closed-loop speed regulating architecture of outer speed loop inside current loop;In torque priority mode, cut off speed loop and input corresponding set torque target current instruction to current loop controller;When monitoring abnormal state exists, trigger safety takeover mode;Constant tension and dynamic impedance feedback adjustment module is configured as passive compensation controller receives tension error, outputs passive adjustment amount for passive heave compensation device and winch correction amount.The present application cooperates and realizes winch motion tracking and passive constant tension adjustment, while improving heave compensation effect, ensure that cable tension is in safe range.

Description

Technical Field

[0001] This invention relates to the field of hybrid heave compensation technology, and more particularly to a combined active and passive heave compensation system. Background Technology

[0002] With my country's exploration and development of the deep sea, heavy-duty long-stroke lifting equipment, aerostats, deep-sea exploration equipment, underwater robots, and deep-sea mining vehicles are being used in deep-sea operations. Under high sea conditions, influenced by ship motion (especially heave and trim), waves, and currents, the lifting system of deep-sea equipment, acting as a load during deployment, retrieval, and underwater operations, must withstand the dynamic loads caused by the equipment's own weight, the cable's own weight, and the ship's heave at depths of several thousand meters. Traditional lifting systems often use high-power winches, compensating for ship heave by adjusting the cable's winding and unwinding speed. However, the large inertia of the winch drum and motor, along with the high rigidity of the transmission system, makes rapid adjustment difficult within a high frequency range, resulting in limited heave compensation capabilities and significant fluctuations in cable tension during critical conditions such as traversing splash zones, landing deceleration, and underwater retrieval. To reduce the impact of waves on the lifting system, a passive wave compensation device has been proposed in engineering. This device provides elastic support through gas springs and absorbs energy through hydraulic damping, achieving near-constant force output within a certain stroke, thus maintaining cable tension within a narrow range.

[0003] Existing passive wave compensation devices are relatively simple in structure and have low energy consumption, but their compensation performance depends on pre-set gas pressure and damping parameters, making timely adjustments difficult once sea conditions or operating conditions change. Furthermore, passive wave compensation devices cannot actively correct the load position, limiting their ability to improve heave compensation accuracy. On the other hand, existing active heave compensation systems measure the ship's heave, roll, and pitch motions using a motion reference unit (MRU), employing a controller to directly drive the winch to achieve load position or speed control. They can also introduce a constant tension control mode, maintaining approximately constant cable tension through torque control. These systems offer high control accuracy, but all dynamic compensation tasks are handled by the winch, requiring significant drive power and energy consumption, placing high performance demands on the motor and electrical systems.

[0004] In heavy-duty hoisting applications such as deep-sea mining vehicles, a combined active and passive heave compensation approach has been proposed in recent years to balance safety, energy efficiency, and control precision. This approach utilizes passive devices to handle most of the static load and low-frequency disturbances, while active actuators handle residual motion. However, existing technologies often treat winches as uncontrollable or only perform basic retrieval and deployment functions. The passive component is typically designed as an independent compensation cylinder or pulley block, resulting in a complex system structure and a lack of unified control strategies and power distribution methods for "winch + passive device" series systems. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a combined active and passive heave compensation system that collaboratively achieves winch motion tracking and passive constant tension adjustment, thereby improving the heave compensation effect while ensuring that the cable tension remains within a safe range.

[0006] To achieve the above-mentioned objectives, the present invention employs the following technical solution:

[0007] This application relates to a combined active and passive heave compensation system, characterized in that it includes:

[0008] The active heave compensation subsystem includes a winch, a ship motion reference unit, and a winch motion control module. The winch motion control module has built-in switchable execution modes: speed priority mode, torque priority mode, and safety takeover mode.

[0009] A passive heave compensation subsystem includes a passive heave compensation device and a constant tension and dynamic impedance feedback adjustment module. The passive heave compensation device includes a frame, a pulley block, a three-chamber cylinder, an accumulator, and multiple parallel inflation branches connected to the pre-charge branch of the accumulator. Each inflation branch is equipped with a corresponding gas cylinder and connected to a controllable valve of the corresponding inflation branch. The cable passes through the winch, pulley block, and crane in sequence and is connected to the deep-sea device. The pulley block includes a fixed pulley and a movable pulley. The fixed pulley is rotatably connected to the frame. The piston rod of the three-chamber cylinder is connected to the movable pulley. Controllable flow valves are respectively installed on the rod inner cavity and the outlet branch of the rod cavity of the three-chamber cylinder. The passive cavity of the three-chamber cylinder is connected to the accumulator.

[0010] The detection assembly includes a tension sensor for detecting cable tension and a displacement sensor for detecting piston rod displacement.

[0011] The winch motion control module is configured as follows:

[0012] The ship's heave displacement data fed back by the ship motion reference unit is acquired in real time, and combined with the preset operating depth command for unified coupling calculation to calculate the real-time cable length compensation and process it into a winch speed command.

[0013] In the speed priority mode, the winch motor adopts a dual closed-loop speed control architecture with an outer speed loop and an inner current loop. The speed loop controller receives the winch speed command, the winch correction amount for correcting the winch speed / torque, the real-time winch speed, and the feedforward compensation amount calculated in advance based on the ship's heave displacement data. It also considers the constraints of tension change rate and whether the cylinder stroke exceeds the limit. The output signal of the current loop controller is limited by the torque limiting module and then output to the winch motor.

[0014] In the torque priority mode, the speed loop is disconnected, and the target current command corresponding to the set torque is input to the current loop controller;

[0015] When an abnormal state is detected, the safety takeover mode is triggered. In the safety takeover mode, the control output is used to adjust the corresponding abnormal state's coordinated adjustment command, which is then converted into a target current command input to the current loop controller.

[0016] The constant tension and dynamic impedance feedback adjustment module is configured as follows:

[0017] The passive compensation controller receives the tension error and considers the tension change rate and the constraint condition characterizing whether the actual stroke of the piston rod exceeds the limit. It outputs the passive adjustment amount for the passive heave compensation device and the winch correction amount. The passive adjustment amount is used to control the opening degree of the controllable valves and controllable flow valves on each corresponding inflation branch.

[0018] In some embodiments of this application, the winch motion control module switches between speed priority mode, torque priority mode, and safety takeover mode via a control mode selection switch;

[0019] The mode selection switch has a first input terminal, a second input terminal, a third input terminal, and an output terminal. The first input terminal receives the target current command output by the speed loop, the second input terminal receives the target current command corresponding to the set torque, the third input terminal receives the coordinated adjustment command, and the output terminal is connected to the connection port where the current loop receives the target current value command.

[0020] When the mode selection switch is controlled to connect the first input terminal to the output terminal, the speed priority mode is entered; when the mode selection switch is controlled to connect the second input terminal to the output terminal, the torque priority mode is entered; and when the mode selection switch is controlled to connect the third input terminal to the output terminal, the safety takeover mode is entered.

[0021] In some embodiments of this application, when the deep-sea equipment is in the routine operation phase underwater, it switches to a speed-priority mode, wherein the routine operation phase includes the routine deployment phase, the routine recovery phase, and the routine seabed operation phase;

[0022] When the deep-sea equipment is in the splash zone crossing stage, the near seabed landing stage, or the underwater recovery and mud breaking stage, it switches to the torque priority mode.

[0023] In some embodiments of this application, the active-passive combined heave compensation system includes:

[0024] The working condition identification and parameter management module is used to determine whether the current working condition is in the splash zone crossing stage, the near seabed landing stage, the underwater recovery and mud breaking stage, or the routine operation stage, based on the deep-sea equipment's depth, winch speed, cable tension, and ship heave displacement data, combined with preset judgment parameters for the splash zone crossing stage, the near seabed landing stage, the underwater recovery and mud breaking stage, and the routine operation stage.

[0025] In some embodiments of this application, when the deep-sea device is in the splash zone crossing stage, a first target tension is set, and the passive compensation controller controls the dynamic reduction of the opening of all controllable flow valves based on the ship heave acceleration data fed back by the ship motion reference unit. The passive compensation controller also controls the opening and closing of controllable valves on the inflation branch to increase the working volume of the passive cavity connected through the accumulator.

[0026] When the depth of the deep-sea device exceeds the preset safety value, it switches to the normal lowering stage. At this time, the opening of all controllable flow valves is restored to the normal basic opening corresponding to the normal lowering stage, and the passive cavity is restored to the normal working volume corresponding to the normal lowering stage.

[0027] When the winch length gauge determines that the deep-sea device is close to the seabed, the gradient of the set target tension is reduced and the opening of all controllable flow valves is dynamically increased. When the passive compensation controller determines that the current position is at the landing critical point, the opening of all controllable flow valves is reduced.

[0028] After the deep-sea device lands, it switches to the conventional seabed operation phase. At this time, the opening of all controllable flow valves is restored to the normal basic opening corresponding to the conventional seabed operation phase.

[0029] After the deep-sea device completes the routine seabed operation phase, it enters the underwater recovery and sludge breaking phase. In the underwater recovery and sludge breaking phase, the upper limit of the set target tension is increased, and the opening degree of all controllable flow valves is first controlled to be reduced. The opening and closing of the controllable valve on the air supply branch is also controlled to reduce the working volume of the passive cavity connected through the accumulator. Then, when the passive compensation controller detects the sludge breaking transient, it controls the opening and closing of the controllable valve on the air supply branch to increase the working volume of the passive cavity connected through the accumulator.

[0030] In some embodiments of this application, after the working condition identification and parameter management module completes the working condition determination, a smooth transition function is triggered, and the parameters of each stage are smoothly switched according to the smooth transition function.

[0031] In some embodiments of this application, the passive compensation controller detects the mud-breaking transient, specifically as follows:

[0032] The tension change reported by the tension sensor and the displacement change rate reported by the displacement sensor are monitored. When the tension drops to the normal recovery tension corresponding to the normal recovery stage, and the displacement change rate exceeds the preset displacement change rate threshold, it indicates that a mud breaking transient has been detected.

[0033] In some embodiments of this application, during the splash zone crossing stage and the underwater recovery and mud breaking stage, the passive compensation controller also synchronously lowers the output torque limit value of the winch motor.

[0034] In some embodiments of this application, the abnormal state includes tension exceeding the limit reported by the tension sensor, the rate of change of tension exceeding the limit reported by the tension sensor, winch speed exceeding the limit, abnormal sensor data, displacement exceeding the limit reported by the displacement sensor, and winch drum travel limit.

[0035] In some embodiments of this application, the fixed pulley is rotatably connected to the top of the frame, and the movable pulley is rotatably connected to the lower part of the fixed pulley. The passive heave compensation device also includes a guide column. The rotating shaft of the movable pulley is slidably connected to the guide column through a roller. When the piston rod of the three-chamber cylinder extends or retracts, it drives the movable pulley to move up and down along the guide column.

[0036] The active-passive composite heave compensation system provided in this application has the following advantages and beneficial effects:

[0037] (1) The winch motion control module and the constant tension and dynamic impedance feedback adjustment module realize the active and passive collaborative division of labor. The passive heave compensation device bears the load weight, cable weight and part of the low frequency wave disturbance. The winch mainly handles residual motion and motion trajectory tracking control, which significantly reduces the rated power and instantaneous torque requirements of the winch.

[0038] (2) Through the lower constant tension and dynamic impedance feedback adjustment module, the equivalent stiffness and damping of the three-chamber cylinder can be adjusted, and the output of the winch can be corrected, so that the cable tension can be kept basically constant under wide sea conditions.

[0039] (3) The passive heave compensation device mainly relies on damping adjustment for elastic energy storage. It only needs to consume a small amount of energy when adjusting parameters. The winch no longer undertakes all heave compensation tasks, and the overall energy consumption of the system is significantly reduced.

[0040] (4) Based on the existing hoisting system, only a passive heave compensation device needs to be added to the load end and the winch drive and control software needs to be upgraded to realize the active and passive composite heave compensation of this application. The modification cost is low and the project is feasible.

[0041] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This diagram shows a partial arrangement of the winch and passive heave compensation device in an embodiment of the active-passive composite heave compensation system proposed in this application.

[0044] Figure 2 This diagram illustrates the connection principle between the accumulator, the three-chamber cylinder, and the gas cylinder group in an embodiment of the active-passive composite heave compensation system proposed in this application.

[0045] Figure 3 This diagram illustrates the principle block diagram of the winch motion control module implemented in an embodiment of the active-passive composite heave compensation system proposed in this application.

[0046] Figure 4 This diagram illustrates the principle block diagram of the constant tension and dynamic impedance feedback adjustment module implemented in an embodiment of the active-passive composite heave compensation system proposed in this application.

[0047] Figure 5 This diagram illustrates the principle block diagram of the phased control strategy in an embodiment of the active-passive composite heave compensation system proposed in this application;

[0048] Figure label:

[0049] 110. Winch; 111. Winch motor; 112. Drum; 113. Cable laying device; 114. Speed ​​loop controller; 115. Current loop controller; 116. Torque limiting module; 117. Speed ​​and torque command generation module; 118. Coordinated adjustment module; 119. Mode selection switch; 210. Passive compensation controller; 220. Passive heave compensation device; 221. Accumulator; 222. First gas cylinder; 222A. First controllable valve; 223. Second gas cylinder Bottle; 223A, Second controllable valve; 224, Third gas cylinder; 224A, Third controllable valve; 225, Fourth gas cylinder; 226, Three-chamber cylinder; 226', Pump station; 226A, Rod inner cavity; 226B, Rod chamber; 226C, Passive chamber; 226D, First controllable flow valve; 226E, Second controllable flow valve; 226F, First replenishing check valve; 226G, Second replenishing check valve; 227, Frame; 228, Fixed pulley; 229, Movable pulley. Detailed Implementation

[0050] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0051] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0052] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0053] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0054] To improve the heave compensation effect, this application proposes a combined active and passive heave compensation system suitable for the hoisting of deep-sea equipment (not shown). Without significantly increasing the system complexity, it achieves coordinated control of active winch motion tracking and passive constant tension regulation. The equivalent stiffness of the passive heave compensation device 220 is changed by adjusting the pre-charge pressure of the accumulator 221 in the passive heave compensation device 220, and the damping of the passive heave compensation device 220 is changed by adjusting the opening of the controllable flow valve. This achieves constant tension regulation under motion tracking control, thereby synergistically improving the heave compensation effect.

[0055] In this application, the deep-sea device refers to a device that needs to be lowered into the water to perform underwater operations, such as a deep-sea mining vehicle or an underwater robot.

[0056] The active-passive composite heave compensation is a combination of active and passive heave compensation. The active heave compensation is implemented for the winch 110 and belongs to the upper-level winch motion tracking control. The passive heave compensation is implemented for the passive heave compensation device 220 and can also correct the speed and torque of the winch 110, belonging to the lower-level horizontal tension adjustment control. The two-layer parallel collaborative control realizes functional division and output coordination.

[0057] In some embodiments of this application, see Figure 1 The winch 110 and the passive heave compensation device 220 are connected in series in the hoisting circuit used to lift the deep-sea device, so that motion tracking control and constant tension adjustment can be achieved on the same cable.

[0058] Figure 1 A schematic diagram of the arrangement of winch 110 and passive heave compensation device 220 is shown, wherein both winch 110 and passive heave compensation device 220 are arranged on the mother ship deck (not shown).

[0059] See Figure 1 The winch 110 has a drum 112 and a steel frame (not marked). The two ends of the main shaft of the drum 112 are supported on the steel frame by large rolling bearings (not shown). A winch motor 111 is arranged on one side of the steel frame. The output shaft of the winch motor 111 is directly connected to the main shaft of the drum 112 to realize the forward and reverse drive of the drum 112. The cable is wound on the drum 112 and the cable is laid out by the cable laying device 113.

[0060] The passive heave compensation device 220 includes a frame 227, a pulley block, a three-chamber hydraulic cylinder 226, an accumulator 221, a pump station 226', and a gas cylinder assembly. (See attached image) Figure 2 In some embodiments of this application, the gas cylinder group is provided with four gas cylinders (referred to as: first gas cylinder 222, second gas cylinder 223, third gas cylinder 224 and fourth gas cylinder 225 respectively), wherein the fourth gas cylinder 225 is connected to the accumulator 221 through a pre-charge branch (unmarked) to provide pre-charge pressure to the accumulator 221.

[0061] See back Figure 1 The frame 227 serves as the foundation for the passive heave compensation device 220 and is arranged on the deck of the mother ship, while the pump station 226' is located on one side of the frame 227.

[0062] In some embodiments of this application, the pulley block includes a fixed pulley 228 and a movable pulley 229. The fixed pulley 228 is rotatably connected to the top of the frame 227, and the movable pulley 229 is rotatably connected to the lower part of the fixed pulley 228. The cable discharged from the cable laying device 113 passes sequentially through the fixed pulley 228, the movable pulley 229, and the crane (not shown, which is arranged on the deck of the mother ship) to connect with the deep-sea equipment. The three-chamber hydraulic cylinder 226 and the accumulator 221 can be arranged on the frame 227. The piston rod in the three-chamber hydraulic cylinder 226 can drive the movable pulley 229 to move up and down to achieve passive heave compensation.

[0063] In some embodiments of this application, the passive heave compensation device 220 further includes a guide column (not shown), a mounting base (not shown) is rotatably connected to the shaft of the movable pulley 229, a roller (not shown) is provided on the mounting base, the roller is slidably connected to the guide column, the guide column acts as a slide rail, and the piston rod and the movable pulley 229 can be hinged, for example, by a pin, so that the movable pulley 229 can be driven to move up and down along the guide column when the piston rod extends or retracts.

[0064] See also Figure 2 It shows the connection diagram between the three-chamber cylinder 226, accumulator 221 and gas cylinder group in the passive heave compensation device 220.

[0065] In some embodiments of this application, controllable flow valves are respectively provided on the outlet branches of the rod inner cavity 226A and the rod cavity 226B of the three-chamber cylinder 226 (the controllable flow valve corresponding to the rod inner cavity 226A is denoted as the first controllable flow valve 226D, and the controllable flow valve corresponding to the rod cavity 226B is denoted as the second controllable flow valve 226E).

[0066] The controllable flow valve can be an electro-proportional flow valve, which can accurately, continuously, and steplessly automatically adjust the valve opening. The hydraulic oil in the rod cavity 226A and the rod chamber 226B can be discharged to the return oil tank (not shown) through the first controllable flow valve 226D and the second controllable flow valve 226E.

[0067] The rod chamber 226B and the rod inner chamber 226A are two working chambers of the three-chamber cylinder 226, corresponding to the piston rod extension and retraction states, respectively. The heave and sag of the deep-sea device corresponds to the synchronous extension and retraction of the piston rod, which simultaneously controls the opening of the first controllable flow valve 226D and the second controllable flow valve 226E, making the three-chamber cylinder 226 a high-energy-consuming damper. This effectively suppresses the violent longitudinal oscillation of the deep-sea device caused by waves, consumes the kinetic energy of wave impact, and ensures that the cable is always in a slightly tensioned state, avoiding cable oscillation, slack, or overload.

[0068] When the opening of the first controllable flow valve 226D and the second controllable flow valve 226E increases, the damping provided by the three-chamber cylinder 226 is small; conversely, the damping provided is large.

[0069] In some embodiments of this application, see also [link to previous document]. Figure 2 The passive heave compensation device 220 is also provided with a first oil replenishment branch (unmarked) connected in parallel with the outlet branch of the rod cavity 226A, and a second oil replenishment branch (unmarked) connected in parallel with the outlet branch of the rod cavity 226B. A first oil replenishment check valve 226F is arranged on the first oil replenishment branch, and a second oil replenishment check valve 226G is arranged on the second oil replenishment branch.

[0070] In some embodiments of this application, the accumulator 221 is connected to the passive chamber 226C of the three-chamber cylinder 226, and the accumulator 221 is connected to multiple parallel charging branches (unmarked) connected in parallel with the pre-charging branch. Each charging branch is equipped with a gas cylinder and connected to a controllable valve (e.g., an electromagnetic shut-off valve) of the corresponding charging branch.

[0071] See also Figure 2 The system is equipped with three gas cylinders and three corresponding inflation branches. The first gas cylinder 222 is connected to the first inflation branch, and a first controllable valve 222A is installed on the first inflation branch. The second gas cylinder 223 is connected to the second inflation branch, and a second controllable valve 223A is installed on the second inflation branch. The third gas cylinder 224 is connected to the third inflation branch, and a third controllable valve 224A is installed on the third inflation branch. The pressure levels of the first gas cylinder 222, the second gas cylinder 223, and the third gas cylinder 224 can be the same or different.

[0072] Thus, the three-chamber hydraulic cylinder 226, accumulator 221, gas cylinder group, and controllable valve combination constitute an adjustable equivalent stiffness hydraulic spring for the passive heave compensation device 220. By controlling the opening and closing of the controllable valve on the corresponding charging branch, the number and pressure level of the gas cylinders connected to the accumulator 221 are switched, and the pre-charge pressure of the accumulator 221 is adjusted, achieving continuous adjustment of the equivalent stiffness to adapt to the load requirements of different working conditions.

[0073] In some embodiments of this application, the passive cavity 226C is provided with a standard volume (i.e., the rated maximum volume of the passive cavity 226C) and a working volume that is dynamically variable under the corresponding precharge pressure. During normal compensation (which will be discussed below), its working volume can be changed by adjusting the precharge pressure of the accumulator 221 to adapt to the system compensation requirements.

[0074] By controlling the controllable valve to close, the working volume of the passive cavity 226C connected through the accumulator 221 is reduced, corresponding to a higher equivalent stiffness. By controlling the controllable valve to open, the working volume of the passive cavity 226C connected through the accumulator 221 is increased, corresponding to a lower equivalent stiffness, which is suitable for the compliant compensation state.

[0075] In some embodiments of this application, the accumulator 221 is further equipped with a displacement sensor or pressure sensor (not shown) for real-time monitoring of the oil-gas interface position and system pressure. The three-chamber cylinder 226 is equipped with a linear displacement sensor (not shown) for measuring piston rod displacement.

[0076] In addition, in order to achieve constant tension control, a tension sensor (not shown) is also provided, which can be arranged at the connection point between the passive heave compensation device 220 and the deep-sea device or at the connection point at the end of the cable, for real-time monitoring of cable tension.

[0077] In some embodiments of this application, a motion reference unit (MRU, not shown) and a control cabinet (not shown) are also arranged on the mother ship. The MRU integrates an accelerometer, a gyroscope and a DSP digital processing unit, and has a built-in Kalman filter. It can measure the ship's heave, pitch, roll and other motions, and send the data to the control cabinet via a serial bus or Ethernet.

[0078] The control cabinet houses a programmable logic controller (PLC) or industrial computer, a winch motor 111 driver (frequency converter), a controllable valve control unit, and a human-machine interface. The control software integrates a winch motion control module (see...). Figure 3 ), constant tension and dynamic impedance feedback adjustment module (see Figure 4 ), operating condition identification and parameter management module (not shown) and fault protection module (not shown).

[0079] The main hardware structure involved in the active-passive composite heave compensation system has been described above. The following section will describe the two-layer collaboration between the winch's active motion tracking and passive constant tension adjustment.

[0080] Figure 3 The diagram shows the principle block diagram of the winch motion control module for winch motion tracking control.

[0081] In some embodiments of this application, see Figure 3 The winch motion control module has built-in switchable speed priority mode, torque priority mode, and safety takeover mode. This switching can be performed via the layout mode selection switch 119.

[0082] The mode selection switch 119 has a first input terminal (not shown), a second input terminal (not shown), a third input terminal (not shown), and an output terminal (not shown). The first, second, and third input terminals are switched to connect to the output terminal. The winch motion control module switches the first, second, and third input terminals to connect to the output terminal according to different working conditions. When the first input terminal and the output terminal are connected, it is in speed priority mode. When the second input terminal and the output terminal are connected, it is in torque priority mode. When the third input terminal and the output terminal are connected, it is in safety takeover mode.

[0083] When operating underwater under normal conditions and without any abnormalities (e.g., tension exceeding limits, tension change rate exceeding limits, cylinder stroke exceeding limits, drum 112 stroke exceeding limits, sensor malfunction, winch speed exceeding limits), the speed priority mode is used to precisely adjust the cable winding and unwinding speed and output torque according to the instructions, adapting to the dual requirements of heave compensation and constant tension control.

[0084] When constant tension control is required but precise position control is not needed under transient and severe conditions such as "crossing the splash zone", "landing near the seabed", and "underwater recovery and mud breaking", switch to torque priority mode. The current loop directly responds to the tension command (which is essentially determined by the output torque of the winch motor 111. The control current is equivalent to the control torque, and thus controls the tension).

[0085] In some embodiments of this application, the fault protection module is equipped with multiple protection logics. When an abnormal situation occurs, the winch motion control module switches to a safe takeover mode, and can reduce the set target tension T. ref To resolve this abnormal situation, measures include limiting the maximum torque of the winch, limiting the maximum speed of the winch, locking the stroke of the three-chamber cylinder 226, pausing the lowering / retrieval of the winch 110, and keeping the load in a safe water depth.

[0086] In some embodiments of this application, turning Figure 5 The working condition identification and parameter management module identifies the location of the deep-sea equipment, the winch speed, and the real-time cable tension T. act By combining the ship's heave and displacement data z with preset judgment parameters for the splash zone crossing stage, near-seabed landing stage, underwater recovery and mud breaking stage, and routine operation stage, it is possible to identify the different working conditions mentioned above (i.e., underwater routine operation, splash zone crossing, near-seabed landing, and underwater recovery and mud breaking). Among them, underwater routine operation includes routine lowering operation, routine recovery operation, and routine seabed operation.

[0087] In some embodiments of this application, during the splash zone crossing phase, the deep-sea device is located at a depth close to the shallow depth, and the winch speed is in a low-speed fine-tuning state (to adapt to smooth control under wave impact), with cable tension T actThe data shows high-frequency and large fluctuations, and the ship's heave displacement data z indicates significant wave disturbance. These situations can be judged by comparing and judging the preset judgment parameters corresponding to the splash zone crossing.

[0088] During the near-seabed landing phase, the depth of the deep-sea device is close to the preset threshold for the seabed (i.e., considered to be near the seabed), and the winch speed continues to slow down (i.e., the lowering speed decreases), and the cable tension T... act The ship's heave displacement data z shows a slow downward trend, and its relationship with the cable tension T is... act The impact of shrinkage can be determined by comparing and judging the preset judgment parameters corresponding to the landing near the seabed.

[0089] During the underwater recovery and mud-breaking stage, the deep-sea device is located near the seabed (its proximity to the seabed can be determined by the winch length and the preset operating depth). The winch speed is in a low-volume recovery state (because mud breaking requires overcoming the suction of the seabed). The cable tension T act The ship's heave displacement data z and cable tension T show a continuous upward trend. act The changes are synergistically related, and these situations can be judged by comparing and judging the preset judgment parameters corresponding to underwater sludge recovery.

[0090] During the routine lowering or retrieval phases, the deep-sea device is located at a mid-water depth, the winch speed is stable (uniform lowering or retrieval), and the cable tension T is constant. act The fluctuations are stable, and the ship's heave displacement data z is linearly matched with the real-time length compensation of the cable. These conditions can be determined by comparing and judging the preset judgment parameters corresponding to the regular lowering or regular recovery phases.

[0091] During routine seabed operations, the deep-sea equipment remains at a stable depth on the seabed, the winch speed approaches zero, and the cable tension T... act Maintain at the set target tension T ref Furthermore, there were no significant fluctuations, and the ship's heave displacement data z only caused a slight displacement of the passive heave compensation device 220. These situations can be judged by comparing and judging the preset judgment parameters corresponding to the conventional seabed operation phase.

[0092] It should be noted that, for example, when a mining vehicle is conducting underwater operations, it needs to go through the following stages in sequence: regular lowering stage → splash zone stage → regular lowering stage → near seabed landing stage → regular seabed operation stage → underwater recovery and mud breaking stage → regular recovery stage.

[0093] In some embodiments of this application, the winch motion control module is used to perform active compensation and is specifically configured to perform the following process.

[0094] See back Figure 3 The above describes active heave compensation.

[0095] In some embodiments of this application, firstly, it is necessary to obtain the winch speed command. Specifically, this is achieved by relying on the ship motion reference unit to collect the ship's heave displacement data z in real time, combined with the preset operating depth command d. ref The unified coupling operation is used to calculate the real-time length compensation of the cable, which is then processed differentially to generate the winch speed command.

[0096] To ensure the smoothness and controllability of the winch speed command, amplitude limiting and filtering feedforward optimization can be performed before using the car speed command to avoid frequent reversing shocks of winch 110.

[0097] The winch speed command is the core objective of winch motion control. The winch 110 is equipped with a drive device with torque control or servo speed control functions. The winch motor 111 is an asynchronous motor or a permanent magnet synchronous motor. The driver adopts a dual closed-loop speed regulation architecture with an inner current loop and an outer speed loop.

[0098] In speed priority mode, the speed loop controller 114 receives winch speed commands and winch correction amounts for correcting the speed / torque of winch 110 (see [reference]). Figure 4 The target current command is output by the lower passive compensation controller 210 (described below), which takes into account the real-time winch speed and the feedforward compensation amount calculated in advance based on the ship's heave displacement data z, and considers the constraints of tension change rate and whether the cylinder stroke exceeds the limit. The speed loop controller 114 outputs the target current command to the current loop controller 115.

[0099] In speed priority mode, the inner current loop completely follows the control instructions of the outer speed loop and operates strictly according to the speed and displacement parameters, so as to fully realize the precise cancellation of the ship's up-and-down swaying by winch 110.

[0100] The current loop controller 115 receives the target current command and the real-time phase current feedback signal of the winch motor 111. Its output signal is limited by the torque limiting module 116 and then output to the winch motor 111.

[0101] Among them, the feedforward compensation amount is a control signal that anticipates disturbances and actively compensates for them in advance. Its function is to connect sea state disturbances with system control and offset the impact of disturbances in advance. Specifically, the feedforward compensation amount is a compensation command calculated in advance based on the ship's heave displacement data z. It can be obtained using existing technical means (e.g., based on model predictive control (MPC) technology, combined with historical ship heave data and current sea state characteristics, to predict the ship's motion trend in the future period).

[0102] To avoid system oscillations caused by over-adjustment, see [reference needed]. Figure 3The tension change rate and cylinder stroke constraint are introduced as feedback signals into the speed loop controller 114.

[0103] In some embodiments of this application, the torque priority mode is automatically triggered under the conditions of "splash zone crossing", "landing near the seabed", and "underwater recovery and mud breaking".

[0104] In torque priority mode, the outer speed loop is cut off, and the speed torque command generation module 117 in the winch motion control module outputs the target current command corresponding to the set torque according to the set torque, and inputs it to the current loop controller 115 to directly regulate the output of the set torque of the winch motor 111, so that the system has the characteristics of "flexible buffer" and effectively prevents the cable from breaking or becoming loose due to wave impact.

[0105] In some embodiments of this application, when entering the safe takeover mode is triggered, the coordinated adjustment module 118 controls the output of a coordinated adjustment command to adjust the corresponding abnormal state, based on the abnormal state, and converts it into a target current command input to the current loop controller 115. Here, the coordinated adjustment command may refer to a torque command, which can be converted into a target current command input to the current loop controller 115.

[0106] For example, when the tension change rate exceeds the limit, the coordinated adjustment command can limit the torque and the winch speed at the same time; when the cylinder stroke exceeds the limit, the coordinated adjustment command can limit the torque and the winch speed and disable it in the output direction at the same time.

[0107] Figure 4 The block diagram of the constant tension and dynamic impedance feedback adjustment module is shown.

[0108] Passive compensation controller 210 receives tension error T err (Set target tension T) ref The cable tension T is fed back in real time by the tension sensor. act Among them, different target tensions T are set under different working conditions. ref It outputs two adjustment values: 1. winch correction value, 2. passive adjustment value.

[0109] Among them, the winch correction amount is used to correct the winch speed command or torque command (see...). Figure 3 This is used to actively reduce the cable-laying tendency of winch 110 or increase the cable-releasing tendency when the tension is too high, through winch correction. When the tension is too low, it can enhance the cable-laying tendency of winch 110 and prevent the rope from slack.

[0110] To avoid system oscillation caused by over-adjustment, the passive compensation controller 210 also couples the cable tension change rate and the actual cylinder stroke limit signal in real time to dynamically generate the adjustment amount as described above. (See [link]) Figure 4 .

[0111] In some embodiments of this application, the passive adjustment amount is used to adjust the equivalent stiffness and damping of the passive heave compensation device 220. The equivalent stiffness adjustment is achieved as described above by controlling the number and pressure level of the gas cylinders connected to the accumulator 221. The damping adjustment is achieved as described above by adjusting the opening size of the first controllable flow valve 226D and the second controllable flow valve 226E.

[0112] In some embodiments of this application, different working conditions have different degrees of compensation, and the parameters involved include: setting target tension, equivalent stiffness, and damping.

[0113] In speed-priority mode, conventional compensation is used. This conventional compensation is applied to the conventional descent phase, conventional seabed operation phase, and conventional recovery phase. The conventional compensation for each phase is preset (i.e., it has a set target tension T). ref The passive cavity 226C has a preset conventional working volume (i.e., a preset conventional equivalent stiffness), and the controllable flow valve has a preset conventional basic opening (i.e., a preset equivalent damping).

[0114] In torque priority mode, different compensation strategies are adopted according to different working conditions. That is, different phased compensation strategies are adopted for the splash zone crossing stage, the near seabed landing stage and the underwater recovery and mud breaking stage, in order to cope with the sudden changes in hydrodynamic and physical boundaries under these harsh deep-sea transient working conditions and solve safety hazards such as load jump, rope slack and cable breakage.

[0115] In some embodiments of this application, see Figure 5 Based on different transient conditions during the splash zone crossing stage, the near-seabed landing stage, and the underwater recovery and mud breaking stage, the phased compensation strategies for each stage are described.

[0116] As described above, passive heave compensation is achieved by the up-and-down movement of the movable pulley 229, and the three-chamber hydraulic cylinder 226 is the driving source for the up-and-down movement of the movable pulley 229. Therefore, in order to achieve passive heave compensation under different transient conditions, the staged compensation strategy mainly involves three parameters: setting the target tension T. ref Equivalent stiffness and damping.

[0117] The following describes the splash zone crossing stage.

[0118] In some embodiments of this application, when a deep-sea device traverses a surface splash zone, wave impact and sudden changes in buoyancy often cause the system to oscillate at high frequencies between "slack rope loss" and "severe tension overload." To cope with this transient condition, a target tension T needs to be set when entering the splash zone. refThe equivalent stiffness and damping are set as follows.

[0119] Set a first target tension (this first target tension is a medium tension and less than the target tension T corresponding to the normal lowering stage). ref This prevents deep-sea equipment from breaking cables due to high-frequency oscillations as it passes through the splash zone.

[0120] In the splash zone, the more intense the wave impact, the higher the ship's heave acceleration data. The larger the value, the more necessary it is to rely on the ship's heave acceleration data. By dynamically and continuously closing the opening of the first controllable flow valve 226D and the second controllable flow valve 226E, the damping is increased, which effectively suppresses the violent longitudinal oscillation of the deep-sea device caused by the waves, consumes the kinetic energy of the wave impact, forcibly limits the cable tension within a safe range, suppresses slack and overload, and ensures that the cable is always in a slightly tensioned state.

[0121] In some embodiments of this application, the passive compensation controller 210 collects ship heave acceleration data in real time. Furthermore, multiple preset acceleration threshold ranges are set according to gradients, and the openings of the first controllable flow valve 226D and the second controllable flow valve 226E are dynamically and synchronously reduced according to the gradients (i.e., damping is increased). In this way, the ship's heave acceleration data is ensured. The damping changes smoothly and synchronously, reducing high-frequency oscillations.

[0122] Specifically, this can be achieved by comparing real-time ship heave acceleration data. The ship's heave acceleration data is determined by comparing it with each preset acceleration threshold range. Within the preset acceleration threshold range, the opening of the first controllable flow valve 226D and the second controllable flow valve 226E is synchronously reduced according to the gradient corresponding to the preset acceleration threshold range.

[0123] In some embodiments of this application, a gradient corresponding to a preset acceleration threshold range can be preset. When it is necessary to increase the damping, the gradient can be invoked to control the first controllable flow valve 226D and the second controllable flow valve 226E to close.

[0124] A preset equivalent stiffness can be set when crossing the splash zone, and when the deep-sea device enters this zone, the equivalent stiffness is controlled to this preset equivalent stiffness. This preset equivalent stiffness can be set relatively low.

[0125] In some embodiments of this application, the passive compensation controller 210 controls the opening and closing of the controllable valve on the inflation branch, increases the working volume of the passive cavity 226C connected through the accumulator 221 (i.e., reduces the equivalent stiffness), and fine-tunes the pre-charge pressure.

[0126] Specifically, the opening / closing of the first controllable valve 222A, the second controllable valve 223A, and / or the third controllable valve 224A needs to be determined based on the preset equivalent stiffness and the pressure level of the gas cylinder on the inflation branch where the controllable valve is located.

[0127] The following describes the regular decentralization phase.

[0128] As the deep-sea device continues to be lowered, when the depth of the deep-sea device exceeds the preset safety value, it indicates that it has passed through the splash crossing zone and entered the normal lowering stage. At this time, the opening of the first controllable flow valve 226D and the second controllable flow valve 226E is restored to the normal basic opening corresponding to the normal lowering stage, and the passive cavity 226C is restored to the normal working volume corresponding to the normal lowering stage.

[0129] The following describes the phase near the seabed landing.

[0130] As the device approaches the seabed for landing, to reduce the descent speed and impact force of the deep-sea device and minimize the risk of damage, the target tension T is first reduced. ref The gradient (i.e., setting the target tension T) ref (the rate of change) and appropriately reduce the damping, and when the landing critical point is reached, control the opening of the first controllable flow valve 226D and the second controllable flow valve 226E to close (i.e., increase the damping).

[0131] In this system, the passive compensation controller 210 begins high-frequency reading of data from the displacement sensor of the three-chamber cylinder 226 when it determines that the load is approaching the seabed. Combined with the ship's heave motion, it accurately captures the landing critical point. Specifically, in some embodiments of this application, when the wave is detected to be in a descending phase and the piston rod displacement change trend conforms to the "characteristics of approaching the seabed", it is considered that a landing critical point has been detected.

[0132] Here, "characteristics near the seabed" refers to the pre-state of the piston rod near the seabed under specific deep-sea device specifications, operating depth, and other conditions (e.g., the displacement rate slows down and tends to stabilize).

[0133] In some embodiments of this application, the process of switching from the target tension corresponding to the conventional descent phase to the target tension corresponding to the near-seabed landing phase is carried out according to the rate of change of the reduced target tension, thus making the target tension a "soft switch".

[0134] When the opening of the controllable flow valve is reduced, its opening can be dynamically reduced according to an exponential curve, so that the motion damping of the three-chamber cylinder 226 increases non-linearly and smoothly. The increased damping can force the combined lowering speed of the winch 110 and the passive heave compensation device 220 to converge rapidly before the deep-sea device touches the bottom, and finally achieve a "soft landing" of the heavy load, effectively solving the problem of damage to the device caused by excessive landing impact.

[0135] During the near-seabed landing phase, the equivalent stiffness provided by the passive heave compensation device 220 can be "the basic stiffness adapted to seabed operations" (for example, the conventional equivalent stiffness corresponding to the conventional seabed operation phase), avoiding landing impact due to excessive stiffness and landing stability due to insufficient stiffness.

[0136] The following describes the routine seabed operation phase.

[0137] After the deep-sea device "soft-landed", it switched to the conventional seabed operation stage. At this time, the opening of the first controllable flow valve 226D and the second controllable flow valve 226E was restored to the conventional basic opening corresponding to the conventional seabed operation stage (which has less damping than at the landing critical point).

[0138] The following describes the underwater sludge breaking stage.

[0139] After the deep-sea equipment completes its routine seabed operations, during the initial stage of lifting the equipment from the seabed, the combined effects of the immense suction of the seabed and the ship's heave can easily lead to cable breakage if conventional constant tension compensation is still used. Therefore, in some embodiments of this application, preparations for extraction are made first, followed by transient protection through mud breaking.

[0140] In some embodiments of this application, during the underwater recovery and sludge breaking stage, the upper limit of the set target tension is increased. When preparing for extraction, the passive heave compensation device 220 controls the closing of the opening of the first controllable flow valve 226D and the second controllable flow valve 226E (i.e., increasing damping), and controls the opening and closing of the controllable valve on the air-charging branch, reducing the working volume of the passive cavity 226C connected through the accumulator 221 (i.e., increasing the equivalent stiffness), and fine-tuning the pre-charge pressure.

[0141] At this time, the three-chamber hydraulic cylinder 226 has high equivalent stiffness and large damping.

[0142] Then, the load is applied slowly. Due to the increased stiffness, when the winch 110 is slightly retracted or the ship is rising, the small displacement of the piston rod can correspond to a large increase in tension, thus slowly and steadily establishing a load to overcome the suction of the seabed and avoiding sudden pulls from the winch 110.

[0143] Subsequently, when the passive compensation controller 210 detects the transient mud breaking, it controls the opening and closing of the controllable valve on the air supply branch, increases the working volume of the passive cavity 226C connected through the accumulator 221 (i.e., reduces the equivalent stiffness), restores the low equivalent stiffness compliant compensation state, and prevents the cable from becoming momentarily slack or jumping over the chute due to the rebound force of the mine car leaving the seabed.

[0144] In some embodiments of this application, the passive compensation controller 210 monitors the tension change fed back by the tension sensor and the displacement change rate fed back by the piston rod displacement sensor in real time. At the moment when the suction of the bottom sediment is determined to be released, it controls the opening and closing of the controllable valve on the inflation branch to increase the working volume of the passive cavity 226C connected through the accumulator 221.

[0145] The moment when the suction of the bottom sediment is released is considered the transient state of breaking the mud. In some embodiments of this application, the determination of the release of the suction of the bottom sediment needs to be combined with the tension feedback from the tension sensor and the displacement feedback from the displacement sensor for joint determination.

[0146] In some embodiments of this application, tension changes are monitored in real time, and high-frequency unloading drops of tension are captured (i.e., the tension drops rapidly and at high frequency from a high value that overcomes the suction of the seabed to the normal recovery tension), which serves as the core signal for the release of the seabed suction.

[0147] To avoid misjudging the release of bottom suction solely based on the tension drop signal (e.g., caused by measurement errors or instantaneous disturbances), it is also necessary to simultaneously monitor the displacement change rate of the piston rod of the three-chamber hydraulic cylinder 226. When the bottom suction is released, the deep-sea device detaches from the seabed, and due to the rebound, the piston rod will produce a small instantaneous displacement, and the displacement change rate will fluctuate significantly (for example, a displacement change rate threshold can be preset; if the displacement change rate exceeds the threshold, it indicates that there is a significant fluctuation; otherwise, it is considered that there is no significant fluctuation). This displacement change rate corresponds to the tension drop signal and is used in conjunction with the judgment to improve the reliability of the determination of the release of bottom suction.

[0148] It should be noted that the specific control of opening / closing of the first controllable valve 222A, the second controllable valve 223A, and / or the third controllable valve 224A needs to be determined based on the preset equivalent stiffness and the pressure level of the gas cylinder on the inflation branch where the controllable valve is located.

[0149] In some embodiments of this application, for the splash zone crossing stage, the near-seabed landing stage, the underwater recovery and mud breaking stage, or the routine operation stage, in order to smoothly achieve the switching of working conditions, the tension, equivalent stiffness and damping of each stage are gradually adjusted according to a smooth transition function to avoid system shock caused by sudden parameter changes.

[0150] The smooth transition function can include an exponential decay function and a linear interpolation function. Depending on the different working conditions, the appropriate function can be selected for gradual parameter adjustment. For example, the exponential decay function is suitable for switching between impact-sensitive working conditions such as the splash zone crossing stage to the normal lowering stage and the underwater recovery mud breaking stage to the normal recovery stage. The linear interpolation function is suitable for switching between working conditions with gentle load changes, such as the normal lowering stage to the splash zone crossing stage.

[0151] In some embodiments of this application, during the aforementioned adjustment of equivalent stiffness and damping, to prevent the winch motor 111 from being pulled backward and bursting when the passive heave compensation device 220 "hardens," during the splash zone crossing stage or underwater recovery and mud-breaking stage, when the equivalent stiffness or damping of the three-chamber cylinder 226 is increased, the passive compensation controller 210 also simultaneously lowers the output torque limit value of the winch motor 111. When encountering instantaneous destructive loads caused by extreme giant waves, if the three-chamber cylinder 226 has reached the high equivalent stiffness or damping impact resistance limit, the winch motor 111 will trigger the torque limit and undergo controlled "passive reverse slippage and yielding," thereby sacrificing positional accuracy to absolutely ensure the safety of the mechanical structure and the main cable.

[0152] The active and passive composite heave compensation system provided in this application has the following advantages: (1) Active and passive collaborative division of labor: The passive heave compensation device 220 bears the load weight, cable weight and part of the low-frequency wave disturbance, and the winch 110 mainly handles residual motion and motion trajectory tracking control, significantly reducing the rated power and instantaneous torque requirements of the winch; (2) Strong tension control capability: Through the lower constant tension and dynamic impedance feedback adjustment module, the equivalent stiffness and damping of the three-chamber cylinder 226 can be adjusted, and the winch output can be corrected. The cable tension can be kept basically constant under wide sea conditions, effectively reducing the tension peak and fluctuation during the splash zone crossing stage, the near seabed landing stage and the underwater recovery mud breaking stage; (3) (3) High energy efficiency: The passive heave compensation device 220 mainly uses elastic energy storage by means of damping adjustment. It only needs to consume a small amount of energy when adjusting parameters. The winch 110 no longer undertakes all heave compensation tasks, and the overall energy consumption of the system is significantly reduced. (4) High structural integration: On the basis of the existing lifting system, only the passive heave compensation device 220 needs to be added to the load end and the winch drive and control software needs to be upgraded to realize the active and passive composite heave compensation of this application. The modification cost is low and the engineering feasibility is good. (5) Wide range of applications: In addition to being applicable to deep-sea devices such as deep-sea mining vehicles and underwater robots, this system can also be applied to shipborne lifting operation scenarios such as the deployment of seabed observation networks and the installation of seabed structural components.

[0153] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by the present invention.

Claims

1. A combined active and passive heave compensation system, characterized in that, include: The active heave compensation subsystem includes a winch, a ship motion reference unit, and a winch motion control module. The winch motion control module has built-in switchable execution modes: speed priority mode, torque priority mode, and safety takeover mode. A passive heave compensation subsystem includes a passive heave compensation device and a constant tension and dynamic impedance feedback adjustment module. The passive heave compensation device includes a frame, a pulley block, a three-chamber cylinder, an accumulator, and multiple parallel inflation branches connected to the pre-charge branch of the accumulator. Each inflation branch is equipped with a corresponding gas cylinder and connected to a controllable valve of the corresponding inflation branch. The cable passes through the winch, pulley block, and crane in sequence and is connected to the deep-sea device. The pulley block includes a fixed pulley and a movable pulley. The fixed pulley is rotatably connected to the frame. The piston rod of the three-chamber cylinder is connected to the movable pulley. Controllable flow valves are respectively installed on the rod inner cavity and the outlet branch of the rod cavity of the three-chamber cylinder. The passive cavity of the three-chamber cylinder is connected to the accumulator. The detection assembly includes a tension sensor for detecting cable tension and a displacement sensor for detecting piston rod displacement. The winch motion control module is configured as follows: The ship's heave displacement data fed back by the ship motion reference unit is acquired in real time, and combined with the preset operating depth command for unified coupling calculation to calculate the real-time cable length compensation and process it into a winch speed command. In the speed priority mode, the winch motor adopts a dual closed-loop speed control architecture with an outer speed loop and an inner current loop. The speed loop controller receives the winch speed command, the winch correction amount for correcting the winch speed / torque, the real-time winch speed, and the feedforward compensation amount calculated in advance based on the ship's heave displacement data. It also considers the constraints of tension change rate and whether the cylinder stroke exceeds the limit. The output signal of the current loop controller is limited by the torque limiting module and then output to the winch motor. In the torque priority mode, the speed loop is disconnected, and the target current command corresponding to the set torque is input to the current loop controller; When an abnormal state is detected, the safety takeover mode is triggered. In the safety takeover mode, the control output is used to adjust the corresponding abnormal state's coordinated adjustment command, which is then converted into a target current command input to the current loop controller. The constant tension and dynamic impedance feedback adjustment module is configured as follows: The passive compensation controller receives the tension error and considers the tension change rate and the constraint condition characterizing whether the actual stroke of the piston rod exceeds the limit. It outputs the passive adjustment amount for the passive heave compensation device and the winch correction amount. The passive adjustment amount is used to control the opening degree of the controllable valves and controllable flow valves on each corresponding inflation branch.

2. The active-passive composite heave compensation system according to claim 1, characterized in that, The winch motion control module switches between speed priority mode, torque priority mode, and safety takeover mode via a control mode selection switch; The mode selection switch has a first input terminal, a second input terminal, a third input terminal, and an output terminal. The first input terminal receives the target current command output by the speed loop, the second input terminal receives the target current command corresponding to the set torque, the third input terminal receives the coordinated adjustment command, and the output terminal is connected to the connection port where the current loop receives the target current value command. When the mode selection switch is controlled to connect the first input terminal to the output terminal, the speed priority mode is entered; when the mode selection switch is controlled to connect the second input terminal to the output terminal, the torque priority mode is entered; and when the mode selection switch is controlled to connect the third input terminal to the output terminal, the safety takeover mode is entered.

3. The active-passive composite heave compensation system according to claim 1, characterized in that, When the deep-sea equipment is in the routine operation phase underwater, it switches to a speed priority mode, wherein the routine operation phase includes the routine deployment phase, the routine recovery phase, and the routine seabed operation phase. When the deep-sea equipment is in the splash zone crossing stage, the near seabed landing stage, or the underwater recovery and mud breaking stage, it switches to the torque priority mode.

4. The active-passive composite heave compensation system according to claim 3, characterized in that, The active-passive composite heave compensation system includes: The working condition identification and parameter management module is used to determine whether the current working condition is in the splash zone crossing stage, the near seabed landing stage, the underwater recovery and mud breaking stage, or the routine operation stage, based on the deep-sea equipment's depth, winch speed, cable tension, and ship heave displacement data, combined with preset judgment parameters for the splash zone crossing stage, the near seabed landing stage, the underwater recovery and mud breaking stage, and the routine operation stage.

5. The active-passive combined heave compensation system according to claim 4, characterized in that, When the deep-sea device is in the splash zone crossing stage, a first target tension is set. The passive compensation controller controls the dynamic reduction of the opening of all controllable flow valves based on the ship heave acceleration data fed back by the ship motion reference unit. The passive compensation controller also controls the opening and closing of the controllable valves on the air charging branch to increase the working volume of the passive cavity connected through the accumulator. When the depth of the deep-sea device exceeds the preset safety value, it switches to the normal lowering stage. At this time, the opening of all controllable flow valves is restored to the normal basic opening corresponding to the normal lowering stage, and the passive cavity is restored to the normal working volume corresponding to the normal lowering stage. When the winch length gauge determines that the deep-sea device is close to the seabed, the gradient of the set target tension is reduced and the opening of all controllable flow valves is dynamically increased. When the passive compensation controller determines that the current position is at the landing critical point, the opening of all controllable flow valves is reduced. After the deep-sea device lands, it switches to the conventional seabed operation phase. At this time, the opening of all controllable flow valves is restored to the normal basic opening corresponding to the conventional seabed operation phase. After the deep-sea device completes the routine seabed operation phase, it enters the underwater recovery and sludge breaking phase. In the underwater recovery and sludge breaking phase, the upper limit of the set target tension is increased, and the opening degree of all controllable flow valves is first controlled to be reduced. The opening and closing of the controllable valve on the air supply branch is also controlled to reduce the working volume of the passive cavity connected through the accumulator. Then, when the passive compensation controller detects the sludge breaking transient, it controls the opening and closing of the controllable valve on the air supply branch to increase the working volume of the passive cavity connected through the accumulator.

6. The active-passive combined heave compensation system according to claim 4 or 5, characterized in that, After the working condition identification and parameter management module completes the working condition determination, it triggers a smooth transition function and smoothly switches the parameters of each stage according to the smooth transition function.

7. The active-passive combined heave compensation system according to claim 5, characterized in that, The passive compensation controller detects the transient state of mud breaking, specifically as follows: The tension change reported by the tension sensor and the displacement change rate reported by the displacement sensor are monitored. When the tension drops to the normal recovery tension corresponding to the normal recovery stage, and the displacement change rate exceeds the preset displacement change rate threshold, it indicates that a mud breaking transient has been detected.

8. The active-passive composite heave compensation system according to claim 5, characterized in that, During the splash zone crossing stage or the underwater recovery and mud breaking stage, the passive compensation controller also synchronously lowers the output torque limit value of the winch motor.

9. The active-passive combined heave compensation system according to claim 1, characterized in that, The abnormal states include tension exceeding the limit reported by the tension sensor, the rate of change of tension exceeding the limit reported by the tension sensor, winch speed exceeding the limit, abnormal sensor data, displacement exceeding the limit reported by the displacement sensor, and winch drum travel limit.

10. The active-passive combined heave compensation system according to claim 1, characterized in that, The fixed pulley is rotatably connected to the top of the frame, and the movable pulley is rotatably connected to the lower part of the fixed pulley. The passive heave compensation device also includes a guide column. The rotating shaft of the movable pulley is slidably connected to the guide column through a roller. When the piston rod of the three-chamber cylinder extends or retracts, it drives the movable pulley to move up and down along the guide column.

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