Ship fin stabilizer

Abstract

The invention relates to the technical field of marine equipment, and particularly discloses a ship fin stabilizer which integrates bionic resistance reduction, intelligent control and energy recovery functions. The fins are of a layered structure of a flexible silica gel skin and a shape memory alloy wire mesh, V-shaped groove arrays are arranged on the surfaces of the fins, and the fins can be self-adaptively deformed into a U shape to reduce resistance. The driving mechanism realizes high-frequency compensation through cooperation of a hydraulic cylinder and piezoelectric ceramics; the energy recovery module converts mechanical energy into electric energy through a two-way pump-generator. According to the device, the rolling trend is predicted through the LSTM neural network, a Q-learning optimization control strategy is combined, the stabilization efficiency and energy efficiency are remarkably improved, and the device is suitable for stable control of ships under high navigational speed and complex sea conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of marine equipment, and specifically discloses a ship fin stabilizer. Background Art

[0002] When a ship encounters wind and waves during navigation, it will experience lateral sway. This lateral sway can reduce the ship's seaworthiness, damage the hull structure, affect the normal operation of equipment and instruments, cause cargo to shift or be damaged by impact, and even cause passengers to become unconscious. To reduce the ship's lateral sway, the best solution currently is to install fin stabilizers on the bottom of the ship's side. Existing fin stabilizers are mostly integral structures. If the fin stabilizer is large, it will occupy a large amount of internal space when retracted, and the requirements for the retraction and deployment device are also high. If the fin stabilizer is small, it will not effectively reduce the sway.

[0003] For example, a ship fin stabilizer described in Chinese Patent Publication No. CN108860500B includes a rotating body, a motor, a retractable wing plate, and a hydraulic cylinder. The device can swing up and down through the retractable wing plate to adjust the angle of the fin stabilizer body according to actual sea conditions. The retractable wing plate provided in the fin stabilizer body can increase or decrease the force-bearing area of the fin stabilizer body under the action of the hydraulic cylinder. The rotating wing plates on both sides of the fin stabilizer body can adjust the angle of the rotating wing plates according to the direction of the impact force of the seawater under the drive of the second motor. However, this device has the following problems: 1. Limited drag reduction capability: The surface roughness and shape design of fixed fins make it difficult to achieve both roll reduction and drag reduction requirements; 2. Adjustment hysteresis: The response speed of the hydraulic system is affected by oil temperature and pressure fluctuations, making it difficult to achieve high-frequency dynamic adjustment; 3. Structural fatigue: Frequent deflection at large angles leads to stress concentration on the shaft, reducing component life; 4. Energy waste: The mechanical energy generated when the fins are reset is not effectively recovered, which increases the overall energy consumption of the ship.

[0004] Therefore, in view of this, the inventor provides a ship fin stabilizer to solve the above-mentioned problem. Summary of the Invention

[0005] The present invention provides a ship roll stabilizer fin, which achieves improved drag reduction performance, optimized roll suppression efficiency and energy recycling through a streamlined fin structure, a drive mechanism and an energy recovery structure.

[0006] In order to achieve the above-mentioned purpose, the basic scheme of the present invention provides a ship anti-roll fin, including streamlined fins symmetrically arranged on both sides of the hull, and the roots of the fins are connected to a drive mechanism through a rotating shaft; the fins include a flexible silicone skin, a shape memory alloy wire mesh and a composite material base layer arranged in sequence from the outside to the inside; a retractable winglet is provided at the end of the fin, and an adaptively adjustable grid is provided on the surface of the winglet; a pressure sensor array for real-time monitoring of water flow impact distribution is provided in the composite material base, and an energy recovery structure is also provided on the rotating shaft.

[0007] Furthermore, the surface of the flexible silicone skin is provided with a V-shaped groove array imitating a whale's tail fin, with a groove depth of 0.5-1.2 mm and a spacing of 3-5 mm. The V-shaped groove can be deformed into a U shape by shrinking the shape memory alloy wire mesh.

[0008] Furthermore, the drive structure includes a hydraulic cylinder, a piezoelectric ceramic driver array, and a universal joint connected to the output end of the hydraulic cylinder; it also includes a control system based on Q-learning reinforcement learning, which generates drive instructions based on a dynamic model prediction algorithm, and the drive instructions are used to coordinate the drag reduction action and the roll reduction action.

[0009] Furthermore, the piezoelectric ceramic driver array performs local attack angle compensation on the leading edge of the fin at a frequency of 200 Hz.

[0010] Furthermore, the driving mechanism also includes a servo motor and a reducer respectively connected to the servo motor and the hydraulic cylinder. The servo motor drives the rotating shaft through the reducer to fine-tune the fin angle. It also includes a sensor module, which includes an inertial measurement unit, a pressure sensor and a speed sensor.

[0011] Furthermore, the dynamic model prediction algorithm adopts an LSTM neural network, and the input parameters include the ship's roll angle, speed, fin force and historical sea condition data.

[0012] Furthermore, the servo motor and the hydraulic cylinder are linked via a clutch and switched to a pure hydraulic drive mode in an emergency.

[0013] Furthermore, the energy recovery structure includes a recovery tank provided in the rotating shaft and a shear thickening fluid filled in the recovery tank, the energy storage device includes a bidirectional swash plate axial piston pump provided in the hull, a permanent magnet synchronous generator coaxially connected to the bidirectional swash plate axial piston pump, and an electromagnetic clutch provided between the bidirectional swash plate axial piston pump and the permanent magnet synchronous generator, the permanent magnet synchronous generator is electrically connected to a piston-type energy accumulator, the bidirectional swash plate axial piston pump is connected to an oil tank, the permanent magnet synchronous generator is electrically connected to a heating plate, the heating plate is connected to a heating pipe for heating the shape memory alloy wire mesh, and the heating pipe is fixed to the rotating shaft.

[0014] Furthermore, the winglet is provided with a grille opening adjustment structure, which includes a rotating shaft rotatably connected to the grille, a connecting bracket provided at the end of the rotating shaft for connecting adjacent rotating shafts, and an adjustment motor for driving the rotating shaft.

[0015] The principles and effects of this basic solution are: 1. Significant drag reduction: The flexible silicone skin, shape memory alloy mesh, and winglets of the anti-whale tail fin can adjust the shape of the fin according to the speed and navigation state, greatly reducing the drag coefficient and saving energy. This solves the problem that the surface roughness and shape design of existing fixed fins cannot achieve both roll reduction and drag reduction requirements. 2. Fast response: The piezoelectric ceramic fine-tuning section shortens the adjustment delay time; 3. Extend service life: by filling the shaft with shear thickening fluid, the fatigue life of the shaft is increased and the service life is extended; 4. Energy Utilization: This energy recovery structure efficiently recovers redundant mechanical energy during the fin stabilizer resetting process through a three-stage "mechanical-hydraulic-electrical" conversion mechanism. Combined with intelligent control strategies, this significantly reduces vessel energy consumption. Its compact design and high reliability make it particularly suitable for deployment in space-constrained ship environments. By utilizing electrical energy in the shape memory alloy mesh and fin surface, the V-groove shape can be adjusted to reduce drag according to navigation conditions, while thermal energy prevents marine organisms from adhering to the fins, extending their service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 The figure shows an overall schematic diagram of a ship fin stabilizer proposed in an embodiment of the present application; Figure 2 A schematic diagram of a ship fin stabilizer proposed in an embodiment of the present application is shown; Figure 3 A schematic diagram of a grille opening adjustment structure of a ship fin stabilizer proposed in an embodiment of the present application is shown; Figure 4 A schematic diagram of a heating plate of a ship's fin stabilizer proposed in an embodiment of the present application is shown; Figure 5 A schematic diagram of the energy recovery structure of a ship fin stabilizer proposed in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0018] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0019] The figure marks in the drawings of the specification include: hull 1, heating tube 2, fin 3, V-groove array 4, wingtip winglet 5, grille 501, rotating shaft 502, connecting bracket 503, hydraulic cylinder 6, rotating shaft 7, shear thickening fluid 701, bidirectional swash plate axial piston pump 8, oil tank 9, piston accumulator 10, heating plate 11, electromagnetic clutch 12, permanent magnet synchronous generator 13, reducer 14, flexible silicone skin 15, shape memory alloy wire mesh 16, sensor array 17, piezoelectric ceramic driver array 18.

[0020] A ship fin stabilizer, for example Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 As shown: It includes a fin 3 assembly: it includes streamlined fins 3 symmetrically installed on both sides of the hull 1, and the roots of the fins 3 are connected to the drive mechanism through a rotating shaft 7; the rotating shaft 7 is made of a hollow titanium alloy tube, and the inner wall is filled with shear thickening fluid 701 (STF). During high-frequency vibration, the fluid hardens to absorb impact energy; an annular load-balancing bearing is set at the root of the fin 3, and an elastic rubber gasket is set in the bearing raceway to disperse the asymmetric load during deflection.

[0021] Driving mechanism: includes a hydraulic cylinder 6, a servo motor and a reducer 14. The hydraulic cylinder 6 provides the basic driving force. The servo motor drives the rotating shaft 502 through the reducer 14 to fine-tune the angle of the fin 3. It also includes a piezoelectric ceramic driver array 18 and a universal joint installed on the leading edge of the fin 3 and located at the output end of the hydraulic cylinder 6. The piezoelectric ceramic driver array 18 performs local attack angle compensation on the leading edge of the fin 3 at a frequency of 200 Hz; the telescopic direction of the output end is adjusted by the set universal joint.

[0022] It also includes a sensor module, which includes an inertial measurement unit, a pressure sensor and a speed sensor.

[0023] In this embodiment, the inertial measurement unit is an inertial measurement unit (IMU) based on Q-learning reinforcement learning: it is used to collect the ship's roll angle, angular velocity and acceleration in real time; Pressure sensor: located on the surface of fin 3 to monitor the impact of water flow on fin 3; Speed sensor: obtain the real-time speed of the ship; By receiving the sensor data, the target fin 3 angle is calculated based on the dynamic model prediction algorithm, and the driving instructions are output to the hydraulic cylinder 6 and the servo motor; Obtain ship motion status and external environment data through IMU, pressure sensor and speed sensor; A dynamic prediction model is built based on the ship's mass distribution, speed, and current sea conditions to calculate the rolling trend within the next 5 seconds. Based on the prediction results, the coordinated driving strategy of the hydraulic cylinder 6 and the servo motor is optimized with the minimum energy consumption as the goal; The servo motor is controlled to perform high-frequency fine adjustment (±2°) on the angle of the fin 3, while the hydraulic cylinder 6 provides low-frequency high-torque compensation; During the intervals between roll stabilization actions, the energy recovery structure stores energy.

[0024] Preferred option: The dynamic prediction model uses an LSTM neural network, trained on historical roll angle data, wave spectra, and changes in vessel load. The servo motor and hydraulic cylinder 6 are linked via a clutch, switching to a purely hydraulic drive mode in an emergency. Fin 3 is made of titanium alloy, 2.5 meters long, and has a maximum deflection angle of ±25°. The hydraulic cylinder 6 in the drive mechanism has an output torque of 5000 N·m, and the servo motor has an accuracy of 0.1°. The sampling frequency of the sensor module is 100Hz, and the operation cycle of the control unit is 50ms.

[0025] The fin 3 is provided with a surface layer, a middle layer and a base layer in sequence from the outside to the inside.

[0026] Surface layer: covered with a flexible silicone skin 15, with a V-shaped groove array 4 imitating a whale's tail fin. The groove depth is 0.5-1.2mm and the spacing is 3-5mm. It is used to guide the laminar boundary layer and reduce water flow resistance by 15%-20%; Middle layer: Embedded with shape memory alloy wire mesh 16, which shrinks and deforms after heating, causing the V-shaped groove to expand into a U-shape to adapt to flow patterns at different speeds. The middle layer is connected to a heating pipe 2, which is coaxially connected to the rotating shaft 502. The heating pipe 2 can be used to circulate heated airflow, thereby heating the shape memory alloy wire mesh 16 and causing it to deform, thereby changing the surface shape of the fin 3 according to the navigation state; Base layer: Made of carbon fiber-epoxy resin composite material, with a pressure sensor array 17 embedded inside to monitor the water flow impact distribution in real time.

[0027] Also includes retractable winglets 5: The winglet 5 is arranged at the end of the fin 3 and is driven to extend and retract by a linear motor. When extended, the aspect ratio is increased to reduce the induced drag, and when retracted, the wave resistance during high-speed navigation is reduced.

[0028] Implementation of drag reduction structures: The surface layer, middle layer and base layer of the fin 3 are combined to form a bionic guide layer. In the bionic guide layer, the shape memory alloy mesh 16 is made of nickel-titanium alloy, and its shrinkage rate is 4% when heated to 80°C, so that the V-shaped groove is transformed into a U-shape. The winglet 5 has a telescopic stroke of 0-1.2m and is provided with a grille 501 opening adjustment structure on the winglet 5. The grille 501 opening structure includes a rotating shaft 502 rotatably connected to the grille, a connecting bracket 503 installed at the end of the rotating shaft 502 for connecting adjacent rotating shafts 502 and an adjustment motor for driving the rotating shaft 503. The adjustment motor is electrically connected to a controller, and the rotation of the adjustment motor is controlled by the controller to adjust the opening of the grille 501. When the speed increases by 5 knots, the grille 501 closes by 15%.

[0029] As the ship accelerates, the control system detects a resistance peak; Retract the winglet 5 and the grille 501 is partially closed; The shape memory alloy wire mesh 16 is heated and shrunk, the groove is transformed into a U-shape, and the boundary layer transition position moves backward; The piezoelectric ceramic actuator fine-tunes the leading edge angle of attack at a frequency of 150 Hz to offset the flutter caused by high-speed flow; When encountering a beam wave, the main hydraulic cylinder 6 deflects the fin 3 to +22° within 0.3s, while the piezoelectric ceramic array compensates for the local angle deviation caused by the impact of the water flow.

[0030] The rotating shaft 502 is also provided with an energy recovery structure, which includes a shear thickening fluid 701 filled in the rotating shaft 502 and an energy storage device, which includes: Bidirectional swash plate axial piston pump 8: As the core energy converter, the pump body adopts a high-strength aluminum alloy shell, which integrates two sets of symmetrically distributed plunger cavities and has adjustable plunger stroke; Permanent magnet synchronous generator 13: Coaxially connected to the pump body of the bidirectional swash plate axial piston pump 8, the stator winding uses H-class insulated copper wire, the rotor is embedded with neodymium iron boron permanent magnets, the rated power is 5-10kW (adapted according to the tonnage of the ship), and is electrically connected to a rectifier, which is electrically connected to a supercapacitor module; Electromagnetic clutch 12: through electromagnetic control, it engages the bidirectional swash plate axial piston pump 8 and the permanent magnet synchronous generator 13 in energy recovery mode (fin 3 reset), and disconnects in active drive mode (fin 3 deflection).

[0031] Installation location: integrated at the rear end of the fin stabilizer shaft 502 and rigidly connected to the shaft 502 via a flange.

[0032] Piston accumulator 10: volume 20-50L, pre-charged nitrogen pressure 15-20MPa, used for temporarily storing recovered hydraulic energy, the piston accumulator 10 is electrically connected to the heating plate 11, the piston accumulator 10 is also electrically connected to the permanent magnet synchronous generator 13, and the supercapacitor module is electrically connected to the piston accumulator 10; Oil tank 9: Made of stainless steel, with a built-in oil suction filter with a filtration accuracy of 10μm, connected to the bidirectional swash plate axial piston pump 8, and a control valve is provided at the connection point.

[0033] Energy conversion path: Hydraulic energy recovery: When the fin 3 is reset, the shaft 502 rotates in the opposite direction to drive the bidirectional swash plate axial piston pump 8 to discharge high-pressure oil to the piston accumulator 10; Electricity generation: When the pressure in the piston accumulator 10 reaches a threshold, the hydraulic oil drives the bidirectional swash plate axial piston pump 8 to rotate, and the permanent magnet synchronous generator 13 generates electricity; Power storage: The electrical energy is converted into direct current by a rectifier and then stored in the piston-type energy storage device 10 and the supercapacitor module (capacity 100-200F, voltage 400-800V).

[0034] Mechanical energy capture: After the fin 3 completes the anti-roll action, the fin 3 begins to swing back under the action of the fluid reaction force and the driving mechanism, driving the rotating shaft 502 to rotate in the opposite direction; Hydraulic conversion: The rotating shaft 502 drives the bidirectional swash plate axial piston pump 8 into pumping mode, converting mechanical energy into hydraulic energy and outputting high-pressure oil to the piston accumulator 10 (peak pressure 18-22 MPa); Pressure storage: The piston accumulator 10 absorbs energy until the pressure reaches a threshold of 20 MPa.

[0035] Power generation trigger: When the pressure of the piston accumulator 10 is ≥20MPa, the control valve opens, and the oil drives the generator to rotate through the bidirectional swash plate axial piston pump 8; Power storage: The generator outputs three-phase AC power, which is stored in the supercapacitor bank after AC / DC conversion, with a charging efficiency of ≥92%; Energy reuse: The stored electrical energy is preferentially supplied to low-voltage equipment such as servo motors and piezoelectric ceramic drivers, reducing the load on the main power grid. At the same time, the heating plate 11 is energized to direct the heat flow into the heating tube 2, thereby being used to heat the shape memory alloy wire mesh 16.

[0036] The use process of the present invention is as follows: Adjustment system workflow: When the ship accelerates to 20 knots, the control system detects a resistance peak: Retract the winglet to 0.8m, and the grid 501 is closed by 30%; The shape memory alloy wire mesh 16 is heated and shrunk, the groove is transformed into a U-shape, and the boundary layer transition position is shifted back by 20%; The piezoelectric ceramic actuator fine-tunes the leading edge angle of attack at a frequency of 150 Hz to offset the flutter caused by high-speed flow; When encountering a beam wave, the main hydraulic cylinder 6 deflects the fin 3 to +22° within 0.3s, while the piezoelectric ceramic array compensates for the local angle deviation caused by the impact of the water flow.

[0037] Measured data: In sea conditions with a wave height of 2.5m, the roll angle is reduced from ±10° to ±3.5°, and the resistance is reduced by 32%; The 502STF filling of the shaft makes the vibration energy absorption efficiency reach 75%, and the maintenance cycle is extended to 2 years. When the ship is sailing, the IMU monitors the roll angle in real time, and the pressure sensor feeds back the force on fin 3; The control unit calls the pre-trained LSTM model to predict the future roll amplitude; If the predicted roll angle exceeds the safety threshold (±8°), the coordinated driving strategy is activated: The hydraulic cylinder 6 pushes the fin 3 to a reference angle (e.g. +15°); The servo motor adjusts ±2° at a frequency of 10Hz to offset high-frequency small roll.

[0038] The present invention significantly improves the anti-rolling efficiency and energy efficiency, and is suitable for ship stability control at high speeds and in complex sea conditions.

[0039] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A ship fin stabilizer, characterized in that: It includes streamlined fins symmetrically arranged on both sides of the hull, and the roots of the fins are connected to the drive mechanism through a rotating shaft; the fins include a flexible silicone skin, a shape memory alloy mesh and a base layer arranged in sequence from the outside to the inside; a retractable winglet is provided at the end of the fin, and the surface of the winglet is provided with an adaptively adjustable grid; a pressure sensor array for real-time monitoring of water flow impact distribution is provided in the base layer, and an energy recovery structure is also provided on the rotating shaft.

2. A ship fin stabilizer according to claim 1, characterized in that: The surface of the flexible silicone skin is provided with a V-shaped groove array imitating a whale's tail fin, with a groove depth of 0.5-1.2 mm and a spacing of 3-5 mm. The V-shaped groove can be contracted and deformed into a U shape by heating the shape memory alloy wire mesh.

3. The ship fin stabilizer according to claim 1, characterized in that: The drive structure includes a hydraulic cylinder, a piezoelectric ceramic driver array provided at the output end of the hydraulic cylinder, and a universal joint connected to the output end of the hydraulic cylinder; it also includes a control system based on Q-learning reinforcement learning, which generates drive instructions based on a dynamic model prediction algorithm. The drive instructions are used to coordinate the adjustment of drag reduction and anti-roll action.

4. The ship fin stabilizer according to claim 3, characterized in that: The piezoelectric ceramic driver array performs local attack angle compensation on the leading edge of the fin at a frequency of 200 Hz.

5. The ship fin stabilizer according to claim 3, characterized in that: The driving mechanism also includes a servo motor and a reducer respectively connected to the servo motor and the hydraulic cylinder. The servo motor drives the rotating shaft through the reducer to fine-tune the fin angle. The driving structure also includes a sensor module, which includes an inertial measurement unit, a pressure sensor and a speed sensor.

6. The ship fin stabilizer according to claim 3, characterized in that: The dynamic model prediction algorithm adopts LSTM neural network, and the input parameters include ship roll angle, speed, fin force and historical sea condition data.

7. The ship fin stabilizer according to claim 5, characterized in that: The servo motor and the hydraulic cylinder are linked via a clutch and switched to a pure hydraulic drive mode in an emergency.

8. The ship fin stabilizer according to claim 6, characterized in that: The energy recovery structure includes a recovery tank arranged in the rotating shaft, a shear thickening fluid filled in the recovery tank and an energy storage device. The energy storage device includes a bidirectional swash plate axial piston pump arranged in the hull, a permanent magnet synchronous generator coaxially connected to the bidirectional swash plate axial piston pump, and an electromagnetic clutch arranged between the bidirectional swash plate axial piston pump and the permanent magnet synchronous generator. The permanent magnet synchronous generator is electrically connected to a piston energy accumulator, the bidirectional swash plate axial piston pump is connected to an oil tank, the piston energy accumulator is electrically connected to a heating plate, the heating plate is connected to a heating pipe for heating the shape memory alloy wire mesh, and the heating pipe is fixed to the rotating shaft.

9. The ship fin stabilizer according to claim 1, characterized in that: The winglet is provided with a grille opening adjustment structure, which includes a rotating shaft rotatably connected to the grille, a connecting bracket provided at the end of the rotating shaft for connecting adjacent rotating shafts, and an adjustment motor for driving the rotating shaft.

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