A deep-sea aquaculture net cage lifting control system and control method

Abstract

The present application relates to the field of aquaculture, and provides a deep-sea aquaculture net cage lifting control system and a control method, which comprises a net cage buoyancy tube, a lifting execution unit, a sensor group and a controller; the lifting execution unit comprises a seawater pump, an integrated valve group and an electric balance valve, and four types of circuits of water injection, water pumping, suspension adjustment and fault emergency pumping are formed by switching the valve group. The sensor group collects net cage height posture data, and the controller realizes closed-loop control. The control method of the present application adopts fuzzy control and cascade double-closed-loop control, realizes bottom sinking, segmented and gradual floating, depth suspension, fault emergency floating and posture correction, suppresses the rapid floating of the net cage away from the bottom, avoids excessive inclination, and switches the emergency circuit to ensure the floating of the net cage in case of main valve failure. The present application realizes the automatic and accurate control of the net cage lifting, improves the safety of deep-sea aquaculture and the maintainability of the equipment, and solves the technical problem of unstable net cage lifting.

Description

Technical Field

[0001] This application relates to the field of aquaculture, specifically to a lifting control system and control method for deep-sea aquaculture cages. Background Technology

[0002] As nearshore aquaculture space becomes increasingly saturated, marine aquaculture is rapidly expanding into deep-sea areas. However, deep-sea areas are characterized by strong winds, high waves, and frequent severe sea conditions such as typhoons, posing a serious threat to aquaculture facilities. During typhoon season, strong winds and huge waves often damage aquaculture cages, cause fish to escape, and even result in mass deaths, causing huge economic losses to aquaculture enterprises.

[0003] The lifting cages are submerged in the sea before a typhoon arrives to avoid the direct impact of wind, waves, and currents; after the typhoon passes, the cages are floated back to the surface to resume normal aquaculture operations. This model is considered an effective way to prevent and mitigate disasters in deep-sea aquaculture.

[0004] Currently, most mainstream lifting cages adopt a pneumatic system, which uses an air compressor to generate compressed gas to drive away and replace the ballast water installed in the cage's buoyancy chamber, thereby changing the cage's buoyancy to achieve lifting and lowering. However, the lifting and lowering process is mainly controlled manually by the air compressor, making the operation uncontrollable. On the one hand, the cage often tilts too much or even fails to lift or lower during the process; on the other hand, when the cage sinks to the bottom, there is often a large amount of suction between the bottom and the seabed silt. Once the buoyancy is exceeded by air and water, the suction disappears instantly, and the excess buoyancy causes the cage to rise by tens of meters in a very short time. This rapid ascent poses a huge threat to the safety of both the aquaculture species and the cage facilities. Summary of the Invention

[0005] Therefore, to address the aforementioned problems, this invention proposes a lifting control system and method for deep-sea aquaculture cages. It solves the technical problem of unstable lifting of the cages.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A lifting control system for deep-sea aquaculture cages includes a cage buoyancy tube, at least one lifting actuator, a sensor group, and a controller; The buoyancy tube of the net cage is provided with an inlet and outlet, and the buoyancy tube of the net cage has a buoyancy cavity inside the net cage; The lifting and lowering actuator includes a seawater pump, an integrated valve group, and an electric balancing valve. The electric balancing valve is installed on the pipeline at the rear end of the integrated valve group and is connected to the inlet and outlet of the buoyancy pipe of the net cage. The controller controls the electric balancing valve to realize the on / off control of the pipeline. The integrated valve group is provided with an electric suction valve, a suction regulating valve, an electric bypass valve, an electric pumping valve, a discharge regulating valve, an electric water supply valve, an electric drain valve, and an electric emergency valve in sequence along the pipeline. The seawater pump is switched via an integrated valve group to form a water injection circuit, a water pumping circuit, a suspension adjustment circuit, and an emergency suction circuit. The water injection circuit is used to inject seawater into the buoyancy cavity of the cage to sink the cage. The pumping circuit is used to extract seawater from the buoyancy chamber of the net cage to make the net cage float. The suspension adjustment circuit maintains the stable suspension of the net cage in different water layers by dynamically adjusting the direction and flow rate of the water inlet and outlet. The fault emergency suction circuit is composed of an electric bypass valve and an electric emergency valve. When the main branch valve fails, the circuit is switched to and the seawater pump actively suctions the cage to make it float in the fault state. The sensor group includes at least one liquid level sensor; The controller is electrically connected to the seawater pump, the integrated valve group, and the sensor group, respectively.

[0007] Further: The number of lifting actuators is one, and the rear pipeline interface of the lifting actuator is connected to the buoyancy pipe of the cage through an electric balance valve.

[0008] The cage buoyancy tube includes multiple independent sections, and the rear end of the lifting actuator is provided with multiple branch interfaces. Each branch interface is connected to the inlet and outlet of the corresponding independent section through an electric balance valve.

[0009] The number of lifting actuators is at least two, and the buoyancy tube of the cage is arranged in at least two independent sections along the circumference. The rear end of each lifting actuator is connected to at least one branch interface, and each branch interface is connected to the inlet and outlet of the corresponding independent section through an electric balance valve.

[0010] The water injection circuit includes an electric suction valve, a suction regulating valve, a seawater pump, a discharge regulating valve, an electric water supply valve, and an electric balance valve connected in sequence. External seawater enters the seawater pump through the electric suction valve and the suction regulating valve, and after being pressurized by the seawater pump, it is injected into the buoyancy pipe of the net cage through the discharge regulating valve, the electric water supply valve, and the electric balance valve.

[0011] The pumping circuit consists of an electric balance valve, an electric pumping valve, an intake regulating valve, a seawater pump, an exhaust regulating valve, and an electric drain valve connected in sequence. Seawater in the buoyancy tube of the net cage enters the seawater pump through the electric balance valve, the electric pumping valve, and the intake regulating valve. After being pumped by the seawater pump, it is discharged to the outside seawater through the exhaust regulating valve and the electric drain valve.

[0012] The suspension regulation circuit consists of an electric suction valve, an electric pumping valve, an electric balancing valve, a suction regulating valve, a seawater pump, a discharge regulating valve, an electric water supply valve, and an electric drainage valve. The electric suction valve, electric water supply valve, electric pumping valve, and electric drainage valve are kept fully open. The external seawater enters the seawater pump through the suction regulating valve after merging with the seawater in the buoyancy pipe of the net cage through the electric balancing valve and the electric pumping valve. The seawater output by the seawater pump enters the seawater pump through the discharge regulating valve and is then reinjected into the buoyancy pipe of the net cage through the electric water supply valve and discharged to the external seawater through the electric drainage valve. The direction and flow rate of the injection and drainage are dynamically regulated by the coordinated opening of the suction regulating valve and the discharge regulating valve.

[0013] The fault emergency suction circuit consists of an electric balance valve, an electric bypass valve, a seawater pump, and an electric emergency valve connected in sequence. Seawater in the buoyancy tube of the net cage enters the seawater pump through the electric balance valve and the electric bypass valve, and after being sucked by the seawater pump, it is discharged to the outside seawater through the electric emergency valve.

[0014] The lifting actuator adopts a distributed, linear installation structure. The seawater pump and the integrated valve group are each independently encapsulated in a watertight small box and fixedly arranged in a linear fashion along the buoyancy tube of the net cage. The connecting pipe section between the electric balance valve and the buoyancy tube of the net cage is equipped with an S-shaped hinged flexible pipe. The lifting actuator is installed on a liftable frame structure and can be raised above the sea surface during maintenance.

[0015] The sensor group includes a front liquid level sensor, a rear liquid level sensor, a left liquid level sensor, and a right liquid level sensor, which are respectively arranged in the front, rear, left, and right positions of the buoyancy tube of the net cage.

[0016] This invention also provides a method for controlling the lifting and lowering of deep-sea aquaculture cages, including the aforementioned lifting and lowering control system for deep-sea aquaculture cages, comprising the following steps: S1. Receive the operating mode command and target height parameters, match the structural parameters of the cage to be controlled, and complete the system initialization; S2. Real-time acquisition of liquid level sensor data from four directions, followed by filtering, moving average, and arithmetic average processing, yields the average height and height change rate of the cage. S3. Based on the selected operating mode, switch the on / off state of the corresponding branch of the integrated valve group, control the electric balance valve to open, and drive the seawater pump to run; S4. Using the target height as the control target, a fuzzy control algorithm is adopted to output the control quantity of the regulating valve opening according to the height deviation level and the rate of change level, and to control the lifting speed of the cage and the target position in a closed loop. S5. Monitor the valve operation status of the system. When a fault is detected in the main branch valve, switch to the fault emergency suction circuit, open the electric bypass valve and the electric emergency valve, and use the seawater pump to actively suction to make the cage float.

[0017] Further: When the operating mode is the bottom-diving mode, steps S3 and S4 are as follows: open the electric suction valve, electric water supply valve and electric balance valve, start the seawater pump to run forward and inject water into the buoyancy chamber of the net cage at a uniform speed; monitor the height change rate and the liquid level difference in the four directions of the net cage in real time, and dynamically adjust the water flow and attitude deviation by controlling the opening of the suction regulating valve and the discharge regulating valve; when the height data and the height change rate simultaneously meet the bottom-touching judgment conditions, gradually reduce the pump power, and close the corresponding valves and pumps in sequence to complete the buffer bottom sinking.

[0018] When the operating mode is floating mode, a segmented and gradual floating control is adopted: multiple intermediate suspension heights are set, and the net cage is stably suspended and stays at each level, so that the farmed fish gradually adapt to the water pressure changes; during each level of floating, the electric water pumping valve, electric drainage valve and electric balance valve are opened, the opening of the suction regulating valve and discharge regulating valve are controlled, and the seawater pump is started to draw seawater from the buoyancy chamber of the net cage.

[0019] When the operating mode is constant depth suspension mode, steps S3 and S4 are as follows: keep the electric suction valve, electric water supply valve, electric pumping valve, electric drain valve, and electric balance valve fully open; adopt cascade double closed-loop control: the outer loop is composed of the target height of the net cage as the main controlled variable, and the inner loop is composed of the liquid level in the buoyancy chamber of the net cage as the secondary controlled variable. The output of the outer loop controller calculated based on the height deviation is used as the liquid level setpoint of the inner loop controller; the inner loop controller coordinates the opening of the suction regulating valve and the discharge regulating valve according to the liquid level deviation, dynamically switches the injection and drainage flow direction and adjusts the injection and drainage flow rate to suppress wave disturbance and ocean current interference, so that the net cage is kept stably suspended within the allowable deviation range of the target height.

[0020] The specific steps of the fuzzy control algorithm are as follows: the deviation between the actual height of the cage and the target height is divided into five levels: negative large, negative medium, zero, positive medium, and positive large; the height change rate is divided into five levels: rising too fast, rising too fast, rate appropriate, sinking too fast, and sinking too fast; fuzzy inference is performed based on the preset fuzzy rule base, the area centroid method is used to defuzzify, and the opening control percentage of the intake regulating valve and the discharge regulating valve is output.

[0021] When configuring multi-zone electric balance valves, the following attitude correction steps are also included: real-time acquisition of liquid level differences in four directions of the net cage, calculation of net cage tilt amount and tilt direction; control of the opening of electric balance valves in the corresponding zones respectively, and reverse injection and drainage compensation adjustment on the tilted side to maintain the horizontal attitude of the net cage.

[0022] The emergency response procedure in step S5 is as follows: after detecting a fault in the main branch valve, close all normally operating main valves and keep the electric balance valve open; open the electric bypass valve and the electric emergency valve; start the seawater pump to pump water from the buoyancy chamber of the net cage at maximum power, and drive the net cage to float to the surface.

[0023] By adopting the aforementioned technical solution, the beneficial effects of the present invention are: This system utilizes a seawater pump and integrated valve assembly to switch between four working paths: an injection circuit, a pumping circuit, a suspension adjustment circuit, and an emergency suction circuit. This replaces the traditional pneumatic manual operation method, enabling proactive control of the net cage's sinking, floating, stable suspension, and emergency response modes, significantly improving the controllability of the lifting and lowering process. Precise regulation of the injection and drainage flow direction and flow rate through regulating valves effectively suppresses sudden buoyancy changes when the net cage leaves the bottom, preventing rapid floating and ensuring the safety of the aquaculture species and the net cage facilities. Combined with a sensor array and controller to form a closed-loop control architecture, it can automatically adjust valve and pump operation based on real-time status feedback, achieving automated and precise control of the lifting and lowering process. An independent emergency suction circuit is added to handle main branch valve malfunctions. In case of failure, the bypass can be quickly switched, and emergency buoyancy can be achieved through active suction by seawater pumps, significantly improving the system's operational reliability and safety in extreme scenarios. Furthermore, the configuration of a single lifting actuator corresponding to a single net cage buoyancy tube results in a simplified structure, lower cost, and suitability for the lifting control needs of small aquaculture net cages. Furthermore, a single lifting actuator paired with multiple independent zone net cage buoyancy tubes allows for independent zone control via electric balance valves in each branch, providing attitude adjustment capabilities while controlling costs. Furthermore, configuring at least two lifting actuators allows for coordinated control of the lifting attitude of large-span net cages, improving the stability and synchronization of large-scale net cage operation. Finally, a clear and complete connection path for the water injection circuit ensures smooth operation during the net cage sinking process. The system features a clear path and controllable water injection flow. Furthermore, level sensors are deployed in four directions to comprehensively collect data on the height and attitude of the cage, providing reliable feedback for attitude correction and precise closed-loop control. Additionally, this method, through a complete process of system initialization, multi-source sensor data processing, valve group path switching, fuzzy algorithm closed-loop adjustment, and emergency fault switching, can precisely control the cage's lifting and lowering rate and target position, while also possessing automatic fault bypass capability, ensuring a smooth, safe, and controllable lifting and lowering process. Furthermore, in the bottom-diving mode, the water inflow and attitude deviation can be dynamically adjusted, with gradual deceleration and buffering upon bottom contact to avoid rigid impact on the seabed and achieve stable sinking. Finally, a segmented, progressive surfacing control system is adopted, with multiple intermediate stages. Suspension at a specific height allows farmed fish to gradually adapt to changes in water pressure, avoiding pressure differential damage and suppressing rapid ascent upon leaving the bottom. Furthermore, the constant-depth suspension mode employs cascaded dual closed-loop control, effectively counteracting wave disturbances and current interference, ensuring the cage remains stably within the target height range. Further, a fuzzy control algorithm intelligently outputs the valve opening based on height deviation and rate of change, achieving smooth, stepless adjustment during lifting and lowering. Additionally, an attitude correction step is added, allowing real-time calculation of cage tilt and reverse compensation adjustment to maintain the cage's horizontal attitude and prevent excessive tilt angles that could cause lifting and lowering malfunctions. Finally, in the event of a main circuit failure, the circuit can be quickly switched to pump water from the cage's buoyancy chamber at maximum power, prioritizing the cage's ascent to a safe position. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall layout of the control system of the present invention.

[0025] Figure 2 This is the piping diagram for the lifting actuator.

[0026] Figure 3 This is a diagram of the water injection circuit piping.

[0027] Figure 4 This is a diagram of the water pumping circuit.

[0028] Figure 5 This is a diagram of the suspension adjustment circuit piping.

[0029] Figure 6 This is the pipeline diagram for the emergency suction circuit in case of failure.

[0030] Figure 7 This is a single-connection layout diagram of the buoyancy tube in a single extended mode.

[0031] Figure 8 This is a diagram showing the buoyancy tube zoning layout for a single extended mode.

[0032] Figure 9 It is a layout diagram of multiple collaborative modes.

[0033] Figure 10 This is a diagram of the controller hardware architecture and communication topology.

[0034] Figure 11 This is a block diagram of the liquid level sensor layout and data processing.

[0035] Figure 12 This is the overall flowchart of the multi-mode lifting and lowering collaborative control method.

[0036] Figure 13 This is the control flowchart for the bottom diving mode.

[0037] Figure 14 This is a diagram of a segmented, gradual ascent pattern.

[0038] Figure 15 This is a flowchart of attitude balance adjustment.

[0039] Figure 16 This is a flowchart for emergency buoyancy control in case of a malfunction.

[0040] Figure label: 1. Net cage buoyancy tube; 2. Lifting actuator; 3. Seawater pump; 4. Integrated valve group; 41. Electric suction valve; 42. Suction regulating valve; 43. Electric bypass valve; 44. Electric pumping valve; 45. Discharge regulating valve; 46. Electric water supply valve; 47. Electric drain valve; 48. Electric emergency valve; 5. Electric balancing valve; 51. Left balancing valve; 52. Right balancing valve; 53. Front balancing valve; 54. Rear balancing valve; 6. Sensor group; 61. Front liquid level sensor; 62. Rear liquid level sensor; 63. Left liquid level sensor; 64. Right liquid level sensor; 7. Connecting flange; 8. Controller; 81. Industrial computer; 82. Analog input module; 83. Analog output module; 84. Frequency converter; 85. DC24V power supply; 9. RS485 bus. Detailed Implementation

[0041] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0042] This embodiment is applied to the lifting control scenario of HDPE aquaculture cages. The system is an independent complete set of devices that can be adapted to aquaculture cages with different structures and specifications and buoyancy tube structures. By actively injecting and draining water into the buoyancy tube 1 of the cage, the overall weight of the cage is changed, and multiple control modes such as bottom sinking and risk avoidance, suspension transition, and floating aquaculture are realized.

[0043] refer to Figures 1 to 16 This embodiment provides a lifting control system for deep-sea aquaculture cages, including a cage buoyancy tube 1, a lifting execution unit 2, a sensor group 6, and a controller 8; the cage buoyancy tube 1 is provided with an inlet and outlet, and the cage buoyancy tube 1 has a cage buoyancy cavity inside.

[0044] The lifting and lowering actuator 2 includes a seawater pump 3, an integrated valve group 4, and an electric balance valve 5. The electric balance valve 5 is installed on the pipeline at the rear end of the integrated valve group 4. The electric balance valve 5 is connected to the inlet and outlet of the buoyancy pipe 1 of the net cage. The controller 8 controls the electric balance valve 5 to realize the on / off control of the pipeline.

[0045] The integrated valve group 4 is provided with an electric suction valve 41, a suction regulating valve 42, an electric bypass valve 43, an electric pumping valve 44, a discharge regulating valve 45, an electric water supply valve 46, an electric drain valve 47, and an electric emergency valve 48 in sequence along the pipeline.

[0046] The seawater pump 3, through the switching of the integrated valve group 4, forms a water injection circuit, a water pumping circuit, a suspension adjustment circuit, and an emergency suction circuit.

[0047] In one implementation, reference Figure 3The water injection circuit includes an electric suction valve 41, a suction regulating valve 42, a seawater pump 3, a discharge regulating valve 45, an electric water replenishment valve 46, and an electric balance valve 5, which are connected in sequence. External seawater enters the seawater pump 3 through the electric suction valve 41 and the suction regulating valve 42. After being pressurized by the seawater pump 3, it is injected into the net cage buoyancy pipe 1 through the discharge regulating valve 45, the electric water replenishment valve 46, and the electric balance valve 5. External seawater → electric suction valve 41 → suction regulating valve 42 → seawater pump 3 → discharge regulating valve 45 → electric water replenishment valve 46 → electric balance valve 5 → net cage buoyancy chamber. The water injection circuit is used to inject seawater into the net cage buoyancy chamber to sink the net cage.

[0048] In one implementation, reference Figure 4 The pumping circuit consists of an electric balance valve 5, an electric pumping valve 44, a suction regulating valve 42, a seawater pump 3, a discharge regulating valve 45, and an electric drain valve 47 connected in sequence. Seawater in the buoyancy tube 1 of the net cage enters the seawater pump 3 through the electric balance valve 5, the electric pumping valve 44, and the suction regulating valve 42. After being pumped by the seawater pump 3, it is discharged to the outside seawater through the discharge regulating valve 45 and the electric drain valve 47. The flow is: net cage buoyancy chamber → electric balance valve 5 → electric pumping valve 44 → suction regulating valve 42 → seawater pump 3 → discharge regulating valve 45 → electric drain valve 47 → outside seawater. The pumping circuit is used to extract seawater from the buoyancy chamber of the net cage to make the net cage float.

[0049] In one implementation, reference Figure 5 The suspension regulation circuit consists of an electric suction valve 41, an electric pumping valve 44, an electric balancing valve 5, a suction regulating valve 42, a seawater pump 3, a discharge regulating valve 45, an electric water supply valve 46, and an electric drain valve 47. The electric suction valve 41, electric water supply valve 46, electric pumping valve 44, and electric drain valve 47 are kept fully open. External seawater, after merging with seawater from the buoyancy pipe 1 of the net cage via the electric suction valve 41 and the electric balancing valve 5 and electric pumping valve 44, enters the seawater pump 3 via the suction regulating valve 42. The seawater output from the seawater pump 3, after passing through the discharge regulating valve 45, is reinjected into the buoyancy pipe 1 of the net cage via the electric water supply valve 46 and discharged to the external seawater via the electric drain valve 47. The opening of the suction regulating valve 42 and the discharge regulating valve 45 are coordinated to dynamically regulate the direction and flow rate of the water supply and drainage. The suspension regulation circuit maintains the stable suspension of the net cage in different water layers by dynamically adjusting the direction and flow rate of the water supply and drainage.

[0050] In one implementation, reference Figure 6The emergency suction circuit consists of an electric balance valve 5, an electric bypass valve 43, a seawater pump 3, and an electric emergency valve 48 connected in sequence. Seawater in the buoyancy tube 1 of the net cage enters the seawater pump 3 through the electric balance valve 5 and the electric bypass valve 43, and is then pumped out through the electric emergency valve 48 to the outside seawater. The flow is: net cage buoyancy chamber → electric balance valve 5 → electric bypass valve 43 → seawater pump 3 → electric emergency valve 48 → outside seawater. In the event of a main valve failure, this circuit is used to pump water and achieve buoyancy. The emergency suction circuit is formed by the cooperation of the electric bypass valve 43 and the electric emergency valve 48. When the main branch valve fails, the circuit switches to this circuit and actively pumps water through the seawater pump 3 to achieve buoyancy of the net cage in the failure state.

[0051] The sensor group 6 includes a front liquid level sensor 61, a rear liquid level sensor 62, a left liquid level sensor 63, and a right liquid level sensor 64, which are respectively arranged at the front, rear, left, and right positions of the buoyancy tube 1 of the net cage. Using sea level as a reference, it collects the height values ​​of the net cage relative to the sea level in real time at the corresponding positions. To address the jumps in measurement data caused by wave fluctuations, refer to... Figure 11 The controller 8 preprocesses the data from the four sensors: first, it removes abnormal jump values ​​by amplitude limiting filtering, then it performs sliding mean filtering, and finally it calculates the arithmetic mean of the four data to obtain the overall average height and height change rate of the cage; at the same time, it calculates the tilt amount and tilt direction of the cage by the difference of the four data, providing a basis for attitude adjustment.

[0052] The controller 8 is electrically connected to the seawater pump 3, the integrated valve group 4 and the sensor group 6 respectively. It is used to receive feedback data from the liquid level sensor, output valve on / off, regulating valve opening and water pump drive signals, and realize multi-mode lifting control of the cage.

[0053] The number of the aforementioned liquid level sensors can be one, two, three, or even more, and can be selected and set according to actual needs.

[0054] In one implementation, reference Figure 7 The number of lifting execution units 2 is one, and the rear pipeline interface of the lifting execution unit 2 is connected to the buoyancy pipe 1 of the net cage through an electric balance valve 5.

[0055] The single-set expansion mode is designed for small net cages, and control can be completed using a single lifting actuator 2. When the net cage's buoyancy pipe 1 is connected, the integrated valve group 4 is equipped with an electric balance valve 5 at its pipeline interface, which is then connected to the net cage's buoyancy pipe 1. The buoyancy pipe only needs one inlet and outlet.

[0056] In one implementation, reference Figure 8The buoyancy tube 1 of the net cage includes multiple independent sections. The rear end of the lifting execution unit 2 is provided with multiple branch interfaces. The electric balance valve 5 includes a left balance valve 51, a right balance valve 52, a front balance valve 53 and a rear balance valve 54. Each branch interface is connected to the inlet and outlet of the corresponding independent section through the electric balance valve 5.

[0057] When the buoyancy tube 1 of the net cage is divided into multiple independent sections and needs to be leveled, the integrated valve group 4 is equipped with multiple branch interfaces at the rear end of the pipeline. Each branch interface is equipped with an independent electric balance valve 5, which is then connected to the inlet and outlet of the buoyancy tube section. In this mode, one set of execution units is connected to the buoyancy tube 1 of the net cage through only one main pipeline interface. By independently opening and closing and adjusting the opening degree of the electric balance valves 5 of each section, the differential control of the injection and drainage volume of different sections is realized, and the attitude correction of the net cage is completed.

[0058] In one implementation, reference Figure 9 The number of lifting execution units 2 is two, and the buoyancy pipe 1 of the net cage is arranged in two independent sections along the circumference. The rear end of each lifting execution unit 2 is connected to the inlet and outlet of the corresponding independent section through an electric balance valve 5.

[0059] For large-span cages, multiple collaborative modes are configured with two or more lifting actuators 2, symmetrically arranged along the main buoyancy tube of the cage on the left and right or around the circumference. Each actuator is independently controlled by the controller 8 and connected to the corresponding buoyancy tube section. Through synchronous control or differentiated adjustment, the overall smooth lifting and attitude correction of the cage can be achieved.

[0060] The number of independent partitions mentioned above can also be three, four or even more, depending on actual needs.

[0061] Each independent partition can connect to two, three, or even more branch interfaces, and the settings can be selected according to actual needs.

[0062] In one embodiment, the lifting actuator 2 adopts a distributed, linear installation structure. The seawater pump 3 and the integrated valve group 4 are each independently encapsulated in a watertight small box and fixedly arranged in a straight line along the buoyancy tube 1 of the net cage. This structure avoids the problem of excessive local buoyancy caused by a centralized large box, prevents deformation of the net cage frame, and ensures that leakage from a single component will not affect other components, thus achieving physical isolation of faults.

[0063] In one embodiment, an S-shaped hinged flexible pipe is installed in the connecting pipe section between the electric balance valve 5 and the buoyancy pipe 1 of the net cage. This pipe is a flexible structure that can be bent and deform with the rise and fall of the net cage, compensating for the pipe displacement during the rise and fall stroke; when the net cage floats to the upper limit position, the pipe interface maintains a preset distance from the sea level to prevent the pipe opening from being exposed for air intake, and at the same time prevents the lifting of the net cage from pulling the rigid pipe and causing sealing failure.

[0064] In one embodiment, the lifting actuator 2 is mounted on a liftable sleeve structure, which can be raised above the sea surface for maintenance. The handrail for fixing the valve pump assembly is a sleeve structure that can move up and down. During normal operation, the sleeve is locked below the sea surface to ensure that the water pump is submerged in the water to prevent cavitation. During maintenance, the connecting flange 7 at the rear end of the electric balance valve 5 is disconnected first, and the sleeve is pulled upward to expose the entire valve pump assembly above the water surface, allowing for disassembly and maintenance without underwater operations.

[0065] The power lines, control signal lines, and sensor data acquisition lines of each valve are tied and laid along the vent pipe at the top of the cage, with sufficient redundant length reserved. They can float on the sea surface as the cage rises and falls, and finally connect to the controller 8 electrical control box above the sea surface.

[0066] In one embodiment, the controller 8 has built-in sinking mode, floating mode, suspension mode, attitude balance adjustment mode and fault emergency mode, supports automatic closed-loop operation and independent manual intervention, and can be adapted to aquaculture cages of different structures and specifications.

[0067] The aforementioned electric balance valve 5 is installed on the main connecting pipe of the net cage. The electric balance valve 5 is the connection hub between the system and the buoyancy pipe 1 of the net cage. The controller 8 realizes the on / off control of the main pipeline. At the same time, the pipeline connection between the system and the net cage can be physically cut off during maintenance.

[0068] refer to Figure 10 The controller 8 has a hardware architecture and communication method. The controller 8 uses an embedded industrial computer 81 as its core, and is equipped with a DC24V power supply 85, an analog input module 82, an analog output module 83 and a frequency converter 84. All functional modules are connected through an RS485 bus 9 and use the MODBUSRTU communication protocol for data interaction.

[0069] Analog input module 82: Connects to analog signals from four liquid level sensors to complete the acquisition and conversion of height data.

[0070] Analog output module 83: Outputs 0-10V analog signals to control the opening of the intake regulating valve 42, the discharge regulating valve 45, and the on / off state of each electric switching valve.

[0071] Inverter 84: Electrically connected to seawater pump 3, it controls the pump speed and output power by adjusting the output frequency, thereby achieving stepless adjustment of the injection and drainage flow rate.

[0072] This invention also provides a method for controlling the lifting and lowering of deep-sea aquaculture cages, with reference to... Figure 12 The deep-sea aquaculture cage lifting control system includes the following steps: S1. Receive the operating mode command and target height parameters, match the structural parameters of the cage to be controlled, and complete the system initialization; S2. Real-time acquisition of liquid level sensor data from four directions, followed by filtering, moving average, and arithmetic average processing, yields the average height and height change rate of the cage. S3. According to the selected operating mode, switch the on / off state of the corresponding branch of the integrated valve group 4, control the electric balance valve 5 to open, and drive the seawater pump 3 to run; S4. Using the target height as the control target, a fuzzy control algorithm is adopted to output the control quantity of the regulating valve opening according to the height deviation level and the rate of change level, and to control the lifting speed of the cage and the target position in a closed loop. S5. Monitor the valve operation status of the system. When a fault is detected in the main branch valve, switch to the fault emergency suction circuit, open the electric bypass valve 43 and the electric emergency valve 48, and use the seawater pump 3 to actively suction to make the cage float.

[0073] Centralized control mode for cage lifting: 1. Bottom Diving Mode refer to Figure 13 When it is necessary to lower the net cage to avoid the platform, follow these steps: (1) The controller 8 receives the sinking command and target depth parameters, initializes the system, and confirms that all valves are in the closed state.

[0074] (2) Open the electric suction valve 41, the electric water supply valve 46 and the electric balance valve 5, start the seawater pump 3 to run in the forward direction, and the seawater is injected into the buoyancy pipe 1 of the net cage through the water injection circuit.

[0075] (3) The average height and height change rate of the cage are collected in real time, and the opening degree of the suction regulating valve 42 and the discharge regulating valve 45 and the speed of the water pump are dynamically adjusted by using fuzzy control algorithm to control the cage to sink at a uniform speed.

[0076] (4) Compare the liquid level data in four directions in real time. If the tilt exceeds the threshold, perform flow compensation correction through the partition balance valve or the dual-sided execution unit to maintain the horizontal posture of the cage.

[0077] (5) When the net cage is detected to have reached the set depth on the seabed and the rate of change of height approaches zero and the power of the water pump load increases stepwise, it is determined that the net cage has touched the bottom. The power of the water pump is gradually reduced, and the corresponding valves and water pumps are closed in sequence to complete the buffer sinking.

[0078] 2. Segmented, gradual ascent mode refer to Figure 14 To prevent the fish from dying due to sudden pressure changes after the net cages rise rapidly from the bottom, a multi-stage suspension system is used for segmented buoyancy control. The process is as follows: (1) The controller 8 receives the buoyancy command and sets the multi-level intermediate suspension height and the final water surface height.

[0079] (2) Open the electric pumping valve 44, the electric drain valve 47 and the electric balance valve 5, start the seawater pump 3 to pump and run, and discharge the seawater in the buoyancy tube through the pumping circuit; at the same time, open the vent pipe at the top of the cage to replenish air into the buoyancy tube and balance the internal and external air pressure.

[0080] (3) In the early stage of the cage leaving the bottom, control the pumping flow rate to maintain a low level, suppress the sudden change in buoyancy at the moment of leaving the bottom, and avoid rapid floating.

[0081] (4) When the net cage rises to the first level of intermediate suspension height, stop pumping water and switch to suspension mode to stay for a preset time to allow the fish to gradually adapt to the water pressure of the water layer.

[0082] (5) After completing the suspension and dwell at each intermediate height in sequence, finally control the net cage to float smoothly to the water surface and close the water pump and the corresponding valve.

[0083] 3. Fixed-depth levitation mode When it is necessary to stabilize the net cage at a set water level for aquaculture, the following controls should be implemented: (1) Keep the electric suction valve 41, electric water supply valve 46, electric water pumping valve 44, electric drain valve 47 and electric balance valve 5 all open.

[0084] (2) With the set target height as the outer loop control target and the liquid level inside the buoyancy tube as the inner loop auxiliary parameter, the flow direction and flow rate of the loop are dynamically adjusted by the coordinated opening of the suction regulating valve 42 and the discharge regulating valve 45: when the net cage is higher than the target height, the water supply flow rate is increased and the water supply flow rate is decreased, so that the net cage sinks slowly; when the net cage is lower than the target height, the water supply flow rate is increased and the water supply flow rate is decreased, so that the net cage floats slowly.

[0085] (3) By adjusting the pump speed, the effects of wave disturbance and ocean current load are offset, so that the cage can be kept stable within the allowable deviation range of the target height.

[0086] 4. Posture balance adjustment mode refer to Figure 15 The attitude balance adjustment control is for multi-zone cages, and the attitude adjustment process is as follows: (1) Real-time data from liquid level sensors in four directions are collected, and the height difference in each direction is calculated to obtain the tilt angle and tilt direction of the cage.

[0087] (2) When the tilt exceeds the set threshold, increase the drainage flow of the tilted side section or decrease its water injection flow, while decreasing the drainage flow of the opposite side section or increasing its water injection flow, and perform reverse compensation through the difference in buoyancy between the two sides.

[0088] (3) When the tilt amount returns to the allowable range, restore the synchronous water injection and drainage of each zone to maintain the horizontal posture of the cage.

[0089] 5. Emergency Floating Mode refer to Figure 16 When the system detects a main valve malfunction and is unable to pump water through the normal circuit, it triggers the emergency buoyancy process: (1) Immediately close all normal main valves and keep electric balance valve 5 open.

[0090] (2) Open the electric bypass valve 43 and the electric emergency valve 48 to connect the fault emergency suction circuit.

[0091] (3) Start the seawater pump 3 at maximum power and draw seawater from the buoyancy tube through the bypass circuit to drive the cage to float to the surface.

[0092] If the suction effect does not meet expectations, the opening of the regulating valve and the frequency of the water pump can be further adjusted to ensure the maximum drainage flow and prioritize ensuring that the net cage floats to a safe position.

[0093] This system uses a fuzzy control algorithm to achieve precise adjustment of the lifting speed. The specific implementation method is as follows: (1) Definition of input and output: The deviation between the actual height of the cage and the target height is the first input, and the height change rate is the second input; the control quantity of the valve opening is the output.

[0094] (2) Domain of discourse and classification of levels: The height deviation is divided into 5 fuzzy levels: negative large, negative medium, zero, positive medium, positive large, corresponding to the cage position being too high, medium-high, no deviation, medium-low, and too low, respectively; The height change rate is divided into 5 fuzzy levels: rising too fast, rising too fast, rate appropriate, sinking too fast, and sinking too fast.

[0095] (3) Fuzzy rule construction: A fuzzy control rule base is established based on the IF-THEN rule. For example, if the deviation is negative and the rate of change is too fast, the output control quantity is positive and the water is injected at full speed to sink; if the deviation is zero and the rate of change is appropriate, the output control quantity is zero and the current flow rate is maintained.

[0096] (4) Defuzzy output: The area centroid method is used to defuzzify the fuzzy inference results to obtain the percentage value of the valve opening, which is then converted into a 0-10V analog signal and output to the valve actuator to achieve smooth flow control.

[0097] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A lifting control system for deep-sea aquaculture cages, characterized in that: It includes the cage buoyancy tube, at least one lifting actuator, sensor group and controller; The buoyancy tube of the net cage is provided with an inlet and outlet, and the buoyancy tube of the net cage has a buoyancy cavity inside the net cage; The lifting and lowering actuator includes a seawater pump, an integrated valve group, and an electric balancing valve. The electric balancing valve is installed on the pipeline at the rear end of the integrated valve group and is connected to the inlet and outlet of the buoyancy pipe of the net cage. The controller controls the electric balancing valve to realize the on / off control of the pipeline. The integrated valve group is provided with an electric suction valve, a suction regulating valve, an electric bypass valve, an electric pumping valve, a discharge regulating valve, an electric water supply valve, an electric drain valve, and an electric emergency valve in sequence along the pipeline. The seawater pump is switched via an integrated valve group to form a water injection circuit, a water pumping circuit, a suspension adjustment circuit, and an emergency suction circuit. The water injection circuit is used to inject seawater into the buoyancy cavity of the cage to sink the cage. The pumping circuit is used to extract seawater from the buoyancy chamber of the net cage to make the net cage float. The suspension adjustment circuit maintains the stable suspension of the net cage in different water layers by dynamically adjusting the direction and flow rate of the water inlet and outlet. The fault emergency suction circuit is composed of an electric bypass valve and an electric emergency valve. When the main branch valve fails, the circuit is switched to and the seawater pump actively suctions the cage to make it float in the fault state. The sensor group includes at least one liquid level sensor; The controller is electrically connected to the seawater pump, the integrated valve group, and the sensor group, respectively.

2. The deep-sea aquaculture cage lifting control system according to claim 1, characterized in that: The number of lifting actuators is one, and the rear pipeline interface of the lifting actuator is connected to the buoyancy pipe of the cage through an electric balance valve.

3. The deep-sea aquaculture cage lifting control system according to claim 2, characterized in that: The cage buoyancy tube includes multiple independent sections, and the rear end of the lifting actuator is provided with multiple branch interfaces. Each branch interface is connected to the inlet and outlet of the corresponding independent section through an electric balance valve.

4. The deep-sea aquaculture cage lifting control system according to claim 1, characterized in that: The number of lifting actuators is at least two, and the buoyancy tube of the cage is arranged in at least two independent sections along the circumference. The rear end of each lifting actuator is connected to at least one branch interface, and each branch interface is connected to the inlet and outlet of the corresponding independent section through an electric balance valve.

5. The deep-sea aquaculture cage lifting control system according to claim 1, characterized in that: The water injection circuit includes an electric suction valve, a suction regulating valve, a seawater pump, a discharge regulating valve, an electric water supply valve, and an electric balance valve connected in sequence. External seawater enters the seawater pump through the electric suction valve and the suction regulating valve, and after being pressurized by the seawater pump, it is injected into the buoyancy pipe of the net cage through the discharge regulating valve, the electric water supply valve, and the electric balance valve.

6. The deep-sea aquaculture cage lifting control system according to claim 1, characterized in that: The pumping circuit consists of an electric balance valve, an electric pumping valve, an intake regulating valve, a seawater pump, an exhaust regulating valve, and an electric drain valve connected in sequence. Seawater in the buoyancy tube of the net cage enters the seawater pump through the electric balance valve, the electric pumping valve, and the intake regulating valve. After being pumped by the seawater pump, it is discharged to the outside seawater through the exhaust regulating valve and the electric drain valve.

7. The deep-sea aquaculture cage lifting control system according to claim 1, characterized in that: The suspension regulation circuit consists of an electric suction valve, an electric pumping valve, an electric balancing valve, a suction regulating valve, a seawater pump, a discharge regulating valve, an electric water supply valve, and an electric drainage valve. The electric suction valve, electric water supply valve, electric pumping valve, and electric drainage valve are kept fully open. The external seawater enters the seawater pump through the suction regulating valve after merging with the seawater in the buoyancy pipe of the net cage through the electric balancing valve and the electric pumping valve. The seawater output by the seawater pump enters the seawater pump through the discharge regulating valve and is then reinjected into the buoyancy pipe of the net cage through the electric water supply valve and discharged to the external seawater through the electric drainage valve. The direction and flow rate of the injection and drainage are dynamically regulated by the coordinated opening of the suction regulating valve and the discharge regulating valve.

8. The deep-sea aquaculture cage lifting control system according to claim 1, characterized in that: The fault emergency suction circuit consists of an electric balance valve, an electric bypass valve, a seawater pump, and an electric emergency valve connected in sequence. Seawater in the buoyancy tube of the net cage enters the seawater pump through the electric balance valve and the electric bypass valve, and after being sucked by the seawater pump, it is discharged to the outside seawater through the electric emergency valve.

9. The deep-sea aquaculture cage lifting control system according to claim 1, characterized in that: The lifting actuator adopts a distributed, linear installation structure. The seawater pump and the integrated valve group are each independently encapsulated in a watertight small box and fixedly arranged in a linear fashion along the buoyancy tube of the net cage. The connecting pipe section between the electric balance valve and the buoyancy tube of the net cage is equipped with an S-shaped hinged flexible pipe. The lifting actuator is installed on a liftable frame structure and can be raised above the sea surface during maintenance.

10. The deep-sea aquaculture cage lifting control system according to claim 1, characterized in that: The sensor group includes a front liquid level sensor, a rear liquid level sensor, a left liquid level sensor, and a right liquid level sensor, which are respectively arranged in the front, rear, left, and right positions of the buoyancy tube of the net cage.

11. A method for controlling the lifting and lowering of deep-sea aquaculture cages, characterized in that: The deep-sea aquaculture cage lifting control system according to any one of claims 1 to 10 includes the following steps: S1. Receive the operating mode command and target height parameters, match the structural parameters of the cage to be controlled, and complete the system initialization; S2. Real-time acquisition of liquid level sensor data from four directions, followed by filtering, moving average, and arithmetic average processing, yields the average height and height change rate of the cage. S3. Based on the selected operating mode, switch the on / off state of the corresponding branch of the integrated valve group, control the electric balance valve to open, and drive the seawater pump to run; S4. Using the target height as the control target, a fuzzy control algorithm is adopted to output the control quantity of the regulating valve opening according to the height deviation level and the rate of change level, and to control the lifting speed of the cage and the target position in a closed loop. S5. Monitor the valve operation status of the system. When a fault is detected in the main branch valve, switch to the fault emergency suction circuit, open the electric bypass valve and the electric emergency valve, and use the seawater pump to actively suction to make the cage float.

12. The method for controlling the lifting and lowering of deep-sea aquaculture cages according to claim 11, characterized in that: When the operating mode is the bottom-diving mode, steps S3 and S4 are as follows: open the electric suction valve, electric water supply valve and electric balance valve, start the seawater pump to run forward and inject water into the buoyancy chamber of the net cage at a uniform speed; monitor the height change rate and the liquid level difference in the four directions of the net cage in real time, and dynamically adjust the water flow and attitude deviation by controlling the opening of the suction regulating valve and the discharge regulating valve; when the height data and the height change rate simultaneously meet the bottom-touching judgment conditions, gradually reduce the pump power, and close the corresponding valves and pumps in sequence to complete the buffer bottom sinking.

13. The method for controlling the lifting and lowering of deep-sea aquaculture cages according to claim 11, characterized in that: When the operating mode is floating mode, a segmented and gradual floating control is adopted: multiple intermediate suspension heights are set, and the net cage is stably suspended and stays at each level, so that the farmed fish gradually adapt to the water pressure changes; during each level of floating, the electric water pumping valve, electric drainage valve and electric balance valve are opened, the opening of the suction regulating valve and discharge regulating valve are controlled, and the seawater pump is started to draw seawater from the buoyancy chamber of the net cage.

14. The method for controlling the lifting and lowering of deep-sea aquaculture cages according to claim 11, characterized in that: When the operating mode is constant depth suspension mode, steps S3 and S4 are as follows: keep the electric suction valve, electric water supply valve, electric pumping valve, electric drain valve, and electric balance valve fully open; adopt cascade double closed-loop control: the outer loop is composed of the target height of the net cage as the main controlled variable, and the inner loop is composed of the liquid level in the buoyancy chamber of the net cage as the secondary controlled variable. The output of the outer loop controller calculated based on the height deviation is used as the liquid level setpoint of the inner loop controller; the inner loop controller coordinates the opening of the suction regulating valve and the discharge regulating valve according to the liquid level deviation, dynamically switches the injection and drainage flow direction and adjusts the injection and drainage flow rate to suppress wave disturbance and ocean current interference, so that the net cage is kept stably suspended within the allowable deviation range of the target height.

15. The method for controlling the lifting and lowering of deep-sea aquaculture cages according to claim 11, characterized in that: The specific steps of the fuzzy control algorithm are as follows: the deviation between the actual height of the cage and the target height is divided into five levels: negative large, negative medium, zero, positive medium, and positive large; the height change rate is divided into five levels: rising too fast, rising too fast, rate appropriate, sinking too fast, and sinking too fast; fuzzy inference is performed based on the preset fuzzy rule base, the area centroid method is used to defuzzify, and the opening control percentage of the intake regulating valve and the discharge regulating valve is output.

16. The method for controlling the lifting and lowering of deep-sea aquaculture cages according to claim 11, characterized in that: When configuring multi-zone electric balance valves, the following attitude correction steps are also included: real-time acquisition of liquid level differences in four directions of the net cage, calculation of net cage tilt amount and tilt direction; control of the opening of electric balance valves in the corresponding zones respectively, and reverse injection and drainage compensation adjustment on the tilted side to maintain the horizontal attitude of the net cage.

17. The method for controlling the lifting and lowering of deep-sea aquaculture cages according to claim 11, characterized in that: The emergency response procedure in step S5 is as follows: after detecting a fault in the main branch valve, close all normally operating main valves and keep the electric balance valve open; open the electric bypass valve and the electric emergency valve; start the seawater pump to pump water from the buoyancy chamber of the net cage at maximum power, and drive the net cage to float to the surface.

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