Variable multi-array submerged leg buoy and method

Abstract

This invention discloses a buoy with variable multi-array submerged legs and a method thereof, relating to the field of wave energy power generation buoy technology. Addressing the problems of poor adaptability to single-dimensional adjustment, high risk of single-point failure, and the impact of air chamber volume fluctuations on power generation efficiency in existing variable parameter buoys during adjustment, this invention employs a coaxial nested dual-parameter collaborative adjustment mechanism, which can simultaneously adjust the area and draft of multiple arrays of independent submerged legs. The intelligent control system pre-stores multiple AQWA simulation optimization databases corresponding to different numbers of legs, achieving dynamic matching between the buoy's natural frequency and the incident wave frequency. This invention significantly broadens the energy capture bandwidth, improves the system's fault tolerance and operational reliability, effectively solves the industry problem of air chamber compression ratio fluctuations, and greatly improves the overall performance and life-cycle economics of wave energy power generation buoys.

Description

Technical Field

[0001] This invention relates to the field of marine renewable energy utilization technology, specifically to the field of wave energy conversion device technology, and particularly to a buoy with variable multi-array submerged legs and a method thereof. Background Technology

[0002] This invention relates to the field of wave energy power generation buoy technology, and in particular to a wave energy power generation buoy that achieves adaptive matching of its natural frequency by adjusting the parameters of its submerged outriggers.

[0003] Wave energy is a clean, pollution-free, and renewable energy source widely distributed along coastal areas worldwide. Its energy density is far higher than that of solar and wind energy, and it features strong predictability and stable energy output, making it the ideal power source for unmanned marine equipment such as ocean observation buoys, communication buoys, and navigation buoys. During wave energy conversion, the relative motion between the device and the waves is crucial. When the device's natural frequency approaches resonance with the wave excitation frequency, its motion amplitude increases significantly, generating stronger kinetic energy and improving energy capture efficiency several times over. Therefore, how to dynamically match the buoy's natural frequency to the wave frequency under different sea conditions has always been a core research direction in this field.

[0004] The heave plate (also known as the sinking leg) is a key component for adjusting the natural frequency of a buoy. It adds damping and mass to the buoy, thereby adjusting the natural frequency, extending the heave period, and improving the heave response in the non-resonance region, ultimately enhancing the platform's overall wave energy capture performance. Traditional wave energy buoys typically use heave plates of fixed size with a fixed natural frequency, and can only be optimized for typical sea conditions in a specific ocean area. However, actual ocean wave conditions are complex and variable, with wave periods fluctuating significantly between 2 and 12 seconds. Buoys with fixed parameters can only maintain high energy capture efficiency within a very narrow frequency range. Under non-design sea conditions, the efficiency drops sharply, and they may even fail to generate electricity normally, severely limiting their applicability and power supply reliability.

[0005] To address the aforementioned problems, those skilled in the art have developed various wave energy generating buoys with variable parameters. For example, Chinese invention patent CN117550018B discloses a wave energy generating buoy, its variable area heave plate, and a control method, which adjusts the buoy's added mass by adjusting the diameter of the heave plate, thereby regulating the natural frequency; Chinese invention patent CN118494679B discloses a wave energy generating buoy and method with variable heave plate depth, which adjusts the buoy's added mass by adjusting the underwater draft of the heave plate; and Chinese invention patent CN119929071B discloses a wave energy generating buoy and method with a heave plate and variable water column cross-sectional area, which adjusts the buoy's dynamic response characteristics by adjusting the cross-sectional area of ​​the water column.

[0006] While the aforementioned existing technologies have overcome the physical limitations of traditional fixed buoys by introducing mechanical adjustment structures and have broadened the energy capture bandwidth to some extent, they still have the following three significant drawbacks: First, the adjustment dimension is singular, making it impossible to achieve precise matching of the natural frequency. Existing designs can only adjust a single parameter, such as the diameter or depth of the heave plate or the cross-sectional area of ​​the water column, while the natural frequency of a buoy is determined by multiple parameters. The adjustment range of a single parameter is limited, making it difficult to cover the common wave frequency ranges in global oceans, and it cannot achieve optimal matching between the natural frequency and wave frequency under complex sea conditions, resulting in limited improvement in energy capture efficiency.

[0007] Secondly, the system suffers from poor reliability and high maintenance costs. Existing variable parameter buoys all rely on a single regulating unit for frequency adjustment, making this unit the weakest link in the entire system. Due to the harsh marine environment, the regulating mechanism is constantly exposed to high salt spray, high humidity, and strong vibration, resulting in a failure rate far higher than that of traditional fixed buoys. Once the regulating unit fails, the entire device will immediately cease operation and require shutdown for repairs. Furthermore, the cost of maintaining marine equipment at sea is extremely high and is subject to weather conditions, often requiring weeks or even months for repairs. This significantly reduces the availability of the device, making its maintenance complexity far outweigh the advantages brought by variable parameter regulation.

[0008] Third, the problem of fluctuating air chamber compression ratio remains unresolved. Adjusting the draft of the heave plate to match the system's natural frequency inevitably alters the overall draft of the float, causing changes in the underwater volume of the air chamber and resulting in fluctuations in the air chamber compression ratio. The power generation efficiency of an air turbine is extremely sensitive to the air chamber compression ratio; deviations from the design operating conditions lead to a sharp drop in turbine efficiency, resulting in the contradictory situation of "the natural frequency being matched, but the overall efficiency of the power generation system significantly decreasing." The aforementioned existing technologies have not considered this issue, leading to actual power generation performance far below theoretical expectations.

[0009] Therefore, there is an urgent need in this field for a wave energy power generation buoy that can achieve multi-parameter coordinated adjustment, has high system reliability, and can effectively suppress fluctuations in the air chamber compression ratio, in order to solve the above-mentioned problems existing in the prior art. Summary of the Invention

[0010] The purpose of this invention is to provide a buoy and method with variable multi-array submerged legs. By coordinating the adjustment of the area and draft of multiple arrays of independent submerged legs, combined with an innovative structure that separates the air chamber and the legs, the wave energy capture bandwidth is significantly broadened, the system's fault tolerance and operational reliability are greatly improved, and the common industry problem of air chamber volume fluctuation affecting power generation efficiency during the adjustment process is solved. This comprehensively improves the overall performance and life-cycle economic efficiency of the wave energy power generation buoy.

[0011] The technical solution adopted in this invention is as follows: A buoy with variable multi-array submersible legs includes a buoy shell, a top end cap, an air turbine, at least two variable submersible legs, a dual-parameter adjustment actuator, and an intelligent control system. The outer shell of the float and the top end cap enclose a sealed inner cavity air chamber, and the air turbine is installed at the through hole of the top end cap and communicates with the inner cavity air chamber. At least two variable sinking legs are evenly distributed along the bottom circumference of the floating body shell, and each variable sinking leg is fixedly connected to the floating body shell through a leg connector. The dual-parameter adjustment actuator is integrated inside each variable submersible leg and is used to synchronously adjust the cross-sectional area and underwater draft of the variable submersible leg. The intelligent control system is electrically connected to the sea state sensor and the dual-parameter adjustment actuator, respectively. It is used to drive the dual-parameter adjustment actuator to adjust the cross-sectional area and draft of the outriggers in coordination according to the real-time sea state and the number of intact variable sinking outriggers, so that the natural frequency of the buoy and the wave excitation frequency are dynamically matched.

[0012] Preferably, the number of variable submersible outriggers is 2, 3, or 4, and each variable submersible outrigger includes a disc base and a flexible sealing ring wrapped around the outside of the disc base; the dual-parameter adjustment actuator adjusts the cross-sectional area of ​​the outrigger by driving the radial expansion / contraction of the flexible sealing ring, and adjusts the underwater draft of the outrigger by driving the axial lifting and lowering of the flexible sealing ring.

[0013] Preferably, the area adjustment unit of the dual-parameter adjustment actuator includes a drive motor, a bevel gear pair, a rotating shaft, a rotary wheel, and several sets of adjustment slider assemblies; The drive motor is fixed on the drive motor base inside the float shell. The bevel gear pair includes a first bevel gear and a second bevel gear that mesh with each other. The second bevel gear is fixedly connected to the output shaft of the drive motor. The first bevel gear is fixedly connected to the upper end of the rotating shaft. The lower end of the rotating shaft is fixedly connected to the wheel. Several sets of adjusting slider assemblies are evenly distributed along the circumference of the disc base. Each set of adjusting slider assemblies includes adjusting slider one and adjusting slider two. The disc base has radial grooves corresponding to the number of adjusting slider one. Adjusting slider one is slidably installed in the radial groove. Its end is pointed and abuts against the outer circumferential surface of the wheel. Its front end has an axial groove. Adjusting slider two is slidably embedded in the axial groove. The outer ends of both the first and second adjusting sliders are fixedly connected to the inner side of the flexible sealing ring. When the wheel rotates, it pushes the first adjusting slider to slide along the radial groove, causing the second adjusting slider and the flexible sealing ring to expand or contract radially.

[0014] Preferably, the depth adjustment unit of the dual-parameter adjustment actuator includes a linear motor, a sliding shaft, and a lifting guide plate; The linear motor is fixed to the linear motor mounting base, and the linear motor mounting base is supported and fixed inside the floating body shell by the protrusion of the drive motor base; The rotating shaft is a hollow shaft, and the sliding shaft is coaxially inserted into the central through hole of the rotating shaft and slides in cooperation with the rotating shaft. The upper end of the sliding shaft is fixedly connected to the output end of the linear motor, and the lower end is fixedly connected to the center of the lifting guide plate. The outer circumferential surface of the lifting guide plate is provided with an axial guide rail corresponding to the number of adjusting sliders. The inner side of the adjusting slider is slidably embedded in the axial guide rail. When the linear motor drives the sliding shaft and the lifting guide plate to move axially, it drives the adjusting slider to slide along the axial groove, thereby driving the flexible sealing ring to move axially to adjust the draft of the outrigger.

[0015] Preferably, each variable submersible outrigger has a radial groove on its disc base, corresponding to 16 sets of adjusting slider assemblies; the outer circumference of the lifting guide plate is provided with 30 axial guide rails, and each adjusting slider is correspondingly embedded in one axial guide rail; all detachable connections between components are achieved by screws.

[0016] Preferably, the intelligent control system includes a leg fault detection module, a sea state data acquisition module, a pre-stored database module, a parameter matching module, an execution drive module, and a feedback optimization module. The outrigger failure detection module is used to detect the number of intact variable submersible outriggers in real time. The sea state data acquisition module is electrically connected to the sea state sensor and is used to collect data on the current water depth, wave height and wave period of the water area. The pre-stored database module stores the mapping relationship between sea state parameters and optimal outrigger cross-sectional area and optimal draft for different numbers of intact outriggers; The parameter matching module is used to match real-time sea state parameters with a pre-stored database and output the optimal adjustment parameters; The execution drive module is used to drive the action of the dual-parameter adjustment actuator according to the optimal adjustment parameters; The feedback optimization module is used to record the energy capture efficiency after each parameter adjustment and iteratively optimize the mapping relationship in the pre-stored database.

[0017] Preferably, the pre-stored database module includes a first database, a second database, and a third database that are independent of each other, corresponding to the optimal parameter mapping relationships when 4, 3, and 2 variable submersible outriggers are intact, respectively; the mapping relationship is pre-established through AQWA simulation and covers sea state ranges with different water depths, wave heights, and wave periods.

[0018] A control method for a variable multi-array submerged outrigger buoy includes the following steps: S1. Outrigger Status Detection: The intelligent control system detects the number of intact variable submersible outriggers through the outrigger fault detection module and calls the optimal parameter mapping library corresponding to the number of outriggers in the pre-stored database. S2. Sea State Data Acquisition: The intelligent control system automatically adjusts the sampling frequency of the sea state sensor according to the real-time sea state to acquire data on the water depth, wave height and wave period of the current water area; S3. Safety Verification: Input the collected sea state parameters into the system for multi-parameter safety verification. If any parameter exceeds the safe operating range of the equipment, the system will enter protection mode and suspend operation; if all parameters are within the safe range, the system will enter the parameter matching stage. S4. Optimal parameter matching: Based on real-time sea state parameters, the optimal outrigger cross-sectional area Si and optimal draft hi under the current sea state are obtained by matching from the called optimal parameter mapping library; S5. Dual-parameter coordinated adjustment: The optimal parameters Si and hi are compared with the current cross-sectional area of ​​the buoy's outriggers S and the current draft h. If there is a difference, the dual-parameter adjustment actuator is driven to synchronously adjust the cross-sectional area of ​​the outriggers to Si and the draft to hi, so that the buoy's natural frequency matches the wave excitation frequency in real time.

[0019] Preferably, in step S2, the intelligent control system adaptively adjusts the sampling frequency according to the fluctuation amplitude of the wave cycle: when the fluctuation amplitude of the wave cycle is greater than a preset threshold, the sampling frequency is increased; when the fluctuation amplitude of the wave cycle is less than the preset threshold, the sampling frequency is decreased.

[0020] Preferably, the following steps are also included: S6 Feedback Optimization: The system records the energy capture efficiency data after each parameter adjustment, forming a feedback data stream, and periodically iterates and optimizes the optimal parameter mapping relationship in the pre-stored database; S7 Periodic Cycle: The system periodically repeats steps S1 to S6 according to an adaptively set time interval to achieve continuous tracking and dynamic response to changes in sea state. When any one or two of the variable sinking outriggers fail and cannot be adjusted, the system automatically calls the optimal parameter mapping library corresponding to the number of remaining intact outriggers to maintain the buoy's degraded operation.

[0021] The beneficial effects of this invention are as follows: This invention addresses three core industry pain points of existing variable parameter wave energy buoys: limited adjustment dimensions, poor system reliability, and fluctuating air chamber compression ratio. Through an innovative integrated design of multiple arrays of independent submersible outriggers and dual-parameter coordinated adjustment, it comprehensively overcomes the performance bottlenecks of existing technologies, achieving a unified approach of wide-band high-efficiency energy capture, highly reliable long-term operation, and stable power generation output. The invention yields the following significant and beneficial technical effects: This invention pioneers a dual-parameter independent and coordinated adjustment mechanism for the outrigger cross-sectional area and draft, completely breaking the limitation of existing technologies that can only adjust a single parameter. Based on the theoretical derivation of the hydrodynamic natural frequency formula and verification by numerous simulation experiments, under the same structural adjustment range, this invention can expand the natural frequency adjustment range of the buoy by more than 45%, covering the common wave frequency range of most sea areas worldwide from 0.1Hz to 1.0Hz. This expands the energy capture bandwidth by more than 3 times, maintaining an energy capture efficiency of over 20% in a wide frequency range with wave periods of 3 to 10 seconds. The average energy capture efficiency is more than 28% higher than that of existing single-parameter adjustable buoys, significantly enhancing the buoy's adaptability to complex and variable sea conditions and solving the problem that traditional buoys can only generate electricity efficiently in narrow sea conditions.

[0022] This invention employs a redundant structure design with multiple arrays of independent submersible outriggers. Each outrigger is equipped with a complete and independent dual-parameter adjustment actuator, forming a natural fault-tolerant system. This fundamentally solves the fatal flaw in existing technologies where a single adjustment unit failure leads to system shutdown. When any one or two outriggers experience mechanical or electrical failures, the intelligent control system can complete fault detection and location within one second and automatically switch to a pre-stored optimized database corresponding to the number of remaining intact outriggers. This drives the remaining outriggers to continue precise dual-parameter coordinated adjustment, enabling the buoy to operate stably in degraded mode. Experimental data shows that even with a single outrigger failure, the buoy's power generation can still reach over 75% of the rated power, and even with a double outrigger failure, it can still reach over 50%. At the same time, the multi-unit redundancy design enables the buoy's mean time between failures (MTBF) to reach over 15,000 hours, more than twice that of existing technologies. This significantly reduces the maintenance frequency and high offshore operation and maintenance costs in marine environments, and significantly improves the long-term operational reliability and economy of the device.

[0023] This invention effectively decouples the coupling relationship between the adjustment mechanism and the overall draft of the buoy by integrating the adjustment mechanism inside the submerged outrigger and using a flexible sealing ring to simultaneously achieve radial expansion and contraction and axial lifting and lowering deformation. It successfully suppresses the volume fluctuation of the underwater air chamber during the outrigger depth adjustment process. Simulation and pool experiments have confirmed that even under extreme adjustment conditions where the outrigger draft changes by 50%, the volume change of the underwater air chamber can still be controlled within 10%, and the overall trend is a smooth nonlinear growth without abrupt changes or amplification effects. This invention completely solves the long-standing technical contradiction in the prior art of "although the natural frequency is matched, the deviation of the air chamber compression ratio leads to a sharp drop in air turbine efficiency." It ensures that the air chamber compression ratio remains stable within the optimal design range of the air turbine throughout the entire process of dynamic adjustment of the buoy's natural frequency, enabling the power generation system to continuously output maximum power and further improving the overall energy conversion efficiency.

[0024] In summary, this invention, through the deep integration of structural innovation and control methods, has comprehensively overcome the core technical challenges of existing wave energy power generation buoys. It can provide long-term, stable, and reliable autonomous power supply for various unmanned marine equipment such as ocean observation buoys, communication buoys, and navigation buoys, freeing them from dependence on traditional battery power supply, significantly extending the service life of marine equipment at sea, and has broad application prospects and significant economic and social benefits. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the internal structure of the buoy and method of the variable multi-array submerged support legs of the present invention.

[0026] Figure 2 This is a schematic diagram of the external structure of the buoy and method with variable multi-array submerged legs according to the present invention.

[0027] Figure 3 This is a schematic diagram of the interior of the heave plate of the buoy and method of the variable multi-array submerged outriggers of the present invention.

[0028] Figure 4 This is a schematic diagram of the internal structure of the heave plate of the buoy and method of the variable multi-array submerged outriggers of the present invention.

[0029] Figure 5 This is a schematic diagram of the adjustment slider one and adjustment slider two of the buoy and method of the variable multi-array submersible outriggers of the present invention.

[0030] Figure 6 This is a schematic diagram of the control module of the buoy and method of the variable multi-array submerged outriggers of the present invention.

[0031] Figure 7 This is a schematic diagram of the external heave plate of the buoy and method of the variable multi-array submerged outriggers of the present invention.

[0032] Figure 8 This is a flowchart of the buoy variation method of the variable multi-array submersible outriggers of the present invention.

[0033] Figure 9 This is a diagram showing the relationship between the leg diameter and the diffraction response value in the variable multi-array submerged leg buoy and method of the present invention. Figure 10 This is a curve showing the relationship between the change in draft of the outriggers and the change in volume of the underwater air chamber in this invention.

[0034] The components are: 1. Air turbine, 2. Top end cap, 3. Screw, 4. Float shell, 5. Linear motor mounting base, 6. Linear motor, 7. Drive motor, 8. Rotating shaft, 9. Sliding shaft, 10. Sealing ring, 11. Second bevel gear, 12. First bevel gear, 13. Drive motor base, 14. Leg connector, 15. Disc base, 16. Rotary wheel, 17. Adjusting slider one, 18. Adjusting slider two, 19. Lifting guide plate. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. This embodiment fully discloses the core structure, transmission relationship, control logic, theoretical basis, and performance verification data of the present invention. Those skilled in the art can manufacture, assemble, and use the variable multi-array submerged leg buoy of the present invention based on the content of this embodiment without creative labor.

[0036] like Figure 1 and Figure 2 As shown, the present invention discloses a buoy with variable multi-array submersible legs, mainly comprising a buoy shell 4, a top end cap 2, an air turbine 1, at least two variable submersible legs, a dual-parameter adjustment actuator, and an intelligent control system. This embodiment uses the preferred configuration of four variable submersible legs as an example for detailed description. This configuration achieves an optimal balance between structural symmetry, dynamic stability, adjustment accuracy, and energy capture efficiency. In practical applications, the configuration can be flexibly adjusted to two or three variable submersible legs according to specific sea conditions, power requirements, and installation conditions. Its core structure, transmission principle, and control method are completely consistent with this embodiment.

[0037] The outer shell of the float 4 is made of seawater-resistant 316L stainless steel or high-strength fiberglass, and has a cylindrical hollow structure with a diameter ranging from 1.2m to 3.0m and a height ranging from 1.5m to 4.0m. The wall thickness is set at 8mm to 15mm depending on the buoy size and design wave height. An 80mm wide flange is machined at the top opening of the outer shell 4, and it is sealed and fixed to the top end cap 2 by 24 M10 stainless steel screws 3 evenly distributed along the circumference. A 5mm thick nitrile rubber sealing gasket is placed between the flange faces. The sealing gasket is integrally molded without splicing seams to ensure the airtightness of the inner cavity. The outer shell 4 and the top end cap 2 together form a sealed inner cavity, which is the core space for converting wave energy into air kinetic energy. Its effective volume is designed to be 0.5m³ according to the buoy power rating. 3 -5.0m 3 The outer surface of the floating body shell 4 is coated with an epoxy zinc-rich primer with a thickness of 100μm and a polyurethane topcoat with a thickness of 200μm, while the inner surface is coated with an anti-corrosion and moisture-proof coating to extend the service life of the device.

[0038] The top end cap 2 is made of the same material as the buoy shell 4, and has a circular through-hole with a diameter of 200mm-500mm at its center. The air turbine 1 is sealed and installed at this through-hole via a flange structure. The air turbine 1 is a bidirectional impulse air turbine, with its air inlet directly connected to the inner chamber and its air outlet open to the atmosphere. The turbine rotor is coaxially connected to the permanent magnet generator. When the buoy shell 4 undergoes heaving motion under the action of waves, the volume of the inner chamber changes periodically, causing periodic fluctuations in the air pressure inside the chamber. This drives the air to flow back and forth between the blades of the air turbine 1, rotating the rotor of the air turbine 1 and ultimately converting the kinetic energy of the air into electrical energy. The rated power of the air turbine 1 is designed to be 100W-5kW according to the buoy size, and the rated speed is 3000rpm-6000rpm, which can meet the power supply requirements of various marine equipment such as ocean observation buoys, communication buoys, and navigation buoys. The air outlet of air turbine 1 is equipped with a stainless steel insect screen and a rain cover to prevent marine life and rainwater from entering the air chamber.

[0039] Four leg connectors 14 are evenly welded to the bottom of the float shell 4 along the circumference. Each leg connector 14 is made of Q355 high-strength alloy steel, is cylindrical, with a diameter of 100mm-200mm and a length of 500mm-1000mm. The upper end of the leg connector 14 is fully welded to the bottom outer surface of the float shell 4. The weld is subjected to ultrasonic testing to ensure that the weld strength meets the requirements. After welding, the weld is ground and treated with anti-corrosion. The lower end is also fully welded to the center of the upper surface of the disc base 15 of the variable sinking leg. The four variable sinking legs are evenly distributed in a cross shape with the central axis of the float shell 4 as the axis of symmetry, and the included angle between two adjacent legs is 90°. This symmetrical arrangement can effectively ensure the stability of the buoy during heave motion, avoid non-heave motions such as rolling and pitching, thereby maximizing the conversion of wave energy into the buoy's heave kinetic energy, and also simplifying the design of the control system.

[0040] Each variable submersible outrigger includes a disc base 15 and a flexible sealing ring 10 wrapped around the outside of the disc base 15. A dual-parameter adjustment actuator is integrated and installed in the enclosed space between the disc base 15 and the buoy shell 4. It is used to synchronously drive the flexible sealing ring 10 to achieve radial expansion / contraction and axial lifting and lowering movements, thereby adjusting the cross-sectional area and underwater draft of the variable submersible outrigger respectively. The dual-parameter adjustment actuator consists of an area adjustment unit and a depth adjustment unit that work independently but collaboratively. The area adjustment unit is used to adjust the cross-sectional area of ​​the outrigger, and the depth adjustment unit is used to adjust the underwater draft of the outrigger. The two units share some transmission components, achieving a compact and lightweight structure, effectively reducing the overall volume and weight of the buoy.

[0041] like Figure 3 and Figure 4 As shown, the area adjustment unit mainly includes a drive motor 7, a bevel gear pair, a rotating shaft 8, a rotating wheel 16, and 16 sets of adjustment slider assemblies. The drive motor 7 is an IP68-rated waterproof servo motor, featuring high precision, high response speed, and good anti-interference capabilities. It can operate stably for extended periods in harsh marine environments with high salt spray and high humidity, within a temperature range of -20℃ to +60℃. The drive motor 7 has a rated power of 50W-500W, a rated speed of 100rpm-500rpm, and a rated torque of 5N·m-50N·m, providing sufficient torque to drive the adjustment slider assembly. The drive motor 7 is fixedly mounted on the center of the upper surface of the drive motor base 13 using four M8 stainless steel screws 3. The drive motor base 13 is disc-shaped, made of 316L stainless steel, with a thickness of 15mm-25mm. Its lower surface is fixedly mounted on the center of the bottom surface inside the float shell 4 using eight M10 stainless steel screws 3.

[0042] The upper surface of the drive motor base 13 has four upwardly protruding support parts evenly arranged along the circumference. Each support part has a height of 100mm-200mm and a width of 50mm-80mm. The top of each of these four support parts is fixedly connected to the lower surface of the linear motor mounting base 5 by two M8 stainless steel screws 3, thereby stably supporting the linear motor mounting base 5 above the drive motor 7, forming a two-layer transmission structure. The linear motor mounting base 5 is also made of 316L stainless steel with a thickness of 15mm-25mm, and has a through hole in its center for the linear motor output shaft to pass through.

[0043] The bevel gear pair includes a first bevel gear 12 and a second bevel gear 11 that mesh with each other. Both gears are made of 20CrMnTi alloy steel and have undergone carburizing and quenching treatment, achieving a surface hardness of HRC58-HRC62 and a core hardness of HRC30-HRC35, exhibiting high wear resistance and load-bearing capacity. The second bevel gear 11 is fixedly connected to the output shaft of the drive motor 7 via a flat key and is axially positioned by a shaft end retaining ring. The first bevel gear 12 is fixedly connected to the upper end of the rotating shaft 8 via a flat key and is also axially positioned by a shaft end retaining ring. The transmission ratio of the two bevel gears is 1:1, enabling constant speed transmission. The gear meshing clearance is adjusted to 0.1mm-0.2mm to ensure smooth transmission and low noise.

[0044] The rotating shaft 8 is a hollow shaft made of 40Cr alloy steel, with an outer diameter of 30mm-50mm and an inner diameter of 15mm-30mm. Its axis coincides with the central axis of the float housing 4. The upper end of the rotating shaft 8 is rotatably connected to the central through hole of the linear motor mounting base 5 via a deep groove ball bearing, and a skeleton oil seal is installed at the bearing for sealing. The lower end passes through the central through hole at the bottom of the float housing 4 and is fixedly connected to the center of the upper surface of the impeller 16 via a flat key. The through hole at the bottom of the float housing 4 is also equipped with a skeleton oil seal and a dustproof ring to prevent seawater and silt from entering the interior of the float. The surface of the rotating shaft 8 is chrome-plated to improve its wear resistance and corrosion resistance.

[0045] The rotating wheel 16 is cylindrical in shape, made of 45# steel, with a diameter of 150mm-300mm and a thickness of 20mm-30mm. The outer circumference of the rotating wheel 16 is machined with an Archimedean spiral cam surface that mates with the pointed ends of the adjusting sliders 17. This surface ensures that when the rotating wheel 16 rotates at a constant speed around its own axis, all 16 adjusting sliders 17 can simultaneously slide smoothly and uniformly in the radial direction, avoiding impact and vibration. A shaft hole with a keyway is machined into the center of the rotating wheel 16 to mate with the rotating shaft 8. The surface of the rotating wheel 16 is blackened to prevent rusting.

[0046] Sixteen sets of adjusting slider assemblies are evenly distributed along the circumference of the disc base 15, with an included angle of 22.5° between adjacent sets. Each set of adjusting slider assemblies includes adjusting slider one 17 and adjusting slider two 18, both made of 6061 aluminum alloy, which is lightweight, high-strength, and corrosion-resistant. The disc base 15 is disc-shaped, made of 316L stainless steel, with a diameter of 800mm-1500mm and a thickness of 20mm-30mm. Sixteen radial grooves are evenly distributed along the circumference of the upper surface of the disc base 15. The length of each groove points towards the center of the disc base 15. The width and depth of the grooves match the dimensions of adjusting slider one 17, with a tolerance grade of H7 / g6, ensuring that adjusting slider one 17 can slide freely along the grooves without significant wobble. The inner surface of the grooves is polished to reduce sliding friction resistance.

[0047] Adjusting slider 17 is slidably installed in the corresponding radial groove. Its end (the end closest to the center of the disc base 15) is machined into a 60° pointed shape. The end face of this pointed shape is hardened to a hardness of HRC45-HRC50 and always maintains contact with the outer circumferential surface of the rotating wheel 16. A square groove extending axially is formed at the front end of adjusting slider 17 (the end furthest from the center of the disc base 15). The length of the groove is 100mm-200mm, and its width and depth match the dimensions of adjusting slider 18, with the same tolerance grade of H7 / g6. Adjusting slider 18 is slidably embedded in this square groove and can slide freely along the axial direction of the groove.

[0048] The outer ends of adjusting slider 17 and adjusting slider 18 are fixedly connected to the inner surface of the flexible sealing ring 10 by a combination of adhesive bonding and stainless steel screws, ensuring a strong and airtight connection. The flexible sealing ring 10 is made of neoprene rubber, which is resistant to seawater corrosion, aging, and tearing, and has good elasticity. It is annular in shape, with a thickness of 5mm-10mm and a Shore hardness of 60-70. The inner edge of the flexible sealing ring 10 is sealed to the outer circumference of the disc base 15 by stainless steel strips and screws, while the outer edge is a free end, allowing it to deform freely with the movement of the adjusting sliders. The surface of the flexible sealing ring 10 is coated with a paint to prevent marine organisms such as barnacles and oysters from adhering to the sealing ring surface and affecting its normal deformation.

[0049] When the drive motor 7 starts, its output shaft drives the second bevel gear 11 to rotate. The second bevel gear 11 drives the first bevel gear 12 to rotate through meshing transmission, which in turn drives the rotating shaft 8 and the rotating wheel 16 to rotate synchronously. When the rotating wheel 16 rotates, the Archimedean spiral cam surface on its outer circumference pushes 16 adjusting sliders 17 to slide outward along their respective radial grooves. Adjusting sliders 17 drive adjusting sliders 18, which are embedded in the groove at their front end, to move outward together, thereby jointly pushing the outer edge of the flexible sealing ring 10 to expand outward and increase the cross-sectional area of ​​the variable submersible leg. Conversely, when the drive motor 7 rotates in the opposite direction, the rotating wheel 16 rotates in the opposite direction. Under the action of the elastic restoring force of the flexible sealing ring 10, adjusting sliders 17 slide inward along the radial groove, driving adjusting sliders 18 to move inward together, causing the flexible sealing ring 10 to contract and reducing the cross-sectional area of ​​the variable submersible leg. By controlling the rotation angle of the drive motor 7, the extension amount of the adjusting slider 17 can be precisely controlled, thereby adjusting the cross-sectional area of ​​the support leg to any target value, with an adjustment range of 50%-150% of the original area.

[0050] like Figure 4 and Figure 6 As shown, the depth adjustment unit mainly includes a linear motor 6, a sliding shaft 9, and a lifting guide plate 19. The linear motor 6 is a waterproof linear servo motor with an IP68 protection rating, featuring high-precision position control (positioning accuracy up to ±0.1mm) and fast response speed (acceleration up to 5m / s²). 2 The linear motor 6 has a rated thrust of 100N-1000N and a rated stroke of 100mm-300mm, which can provide sufficient thrust to drive the flexible sealing ring 10 to move up and down. The linear motor 6 is fixedly mounted on the center position of the upper surface of the linear motor mounting base 5 by four M8 stainless steel screws 3. Its output shaft extends downward, passes through the center through hole of the linear motor mounting base 5, and is welded and fixedly connected to the upper end of the sliding shaft 9.

[0051] The sliding shaft 9 is a solid shaft made of 40Cr alloy steel. Its diameter matches the inner diameter of the rotating shaft 8, with a tolerance grade of H7 / g6. The axis of the sliding shaft 9 coincides with the axis of the rotating shaft 8 and is coaxially inserted into the central through hole of the rotating shaft 8. A self-lubricating sliding bearing forms a sliding fit between the sliding shaft 9 and the inner hole of the rotating shaft 8, allowing it to slide freely along the axial direction of the rotating shaft 8. The length of the sliding shaft 9 is designed according to the rated stroke of the linear motor 6, ensuring that the sliding shaft 9 will not interfere with the rotating shaft 8 throughout the entire stroke range of the linear motor 6. The surface of the sliding shaft 9 is chrome-plated to improve its wear resistance and corrosion resistance.

[0052] The lower end of the sliding shaft 9 passes through the central through hole of the rotating wheel 16 and is welded and fixedly connected to the center of the upper surface of the lifting guide plate 19. The lifting guide plate 19 is disc-shaped and made of 6061 aluminum alloy. Its diameter is slightly smaller than that of the disc base 15, and its thickness is 15mm-25mm. Thirty axial guide rails are evenly distributed along the circumference of the outer circumference of the lifting guide plate 19. The length direction of each axial guide rail is parallel to the axis of the lifting guide plate 19, and the cross-section of the guide rail is dovetail-shaped, which effectively prevents the adjusting slider 18 from falling off the guide rail. The inner end face of each adjusting slider 18 is machined with a guide groove that matches the dovetail-shaped guide rail. The adjusting slider 18 is slidably embedded in the corresponding axial guide rail through the guide groove and can slide freely along the length direction of the axial guide rail. The mating surfaces of the guide rail and the guide groove are polished to reduce sliding friction resistance.

[0053] When the linear motor 6 starts, its output shaft drives the sliding shaft 9 to move up and down along the axial direction. The sliding shaft 9 then drives the lifting guide plate 19 to move up and down synchronously. When the lifting guide plate 19 moves up and down, the axial guide rail on its outer circumference will drive all the adjusting sliders 18 to slide up and down along the square groove at the front end of the adjusting slider 17. The adjusting sliders 18 then drive the outer edge of the flexible sealing ring 10 to move up and down, thereby changing the underwater draft of the variable submersible outrigger. Specifically, when the linear motor 6 drives the sliding shaft 9 to move downward, the lifting guide plate 19 drives the adjusting sliders 18 to slide downward, pushing the flexible sealing ring 10 to extend downward and increasing the underwater draft of the outrigger; when the linear motor 6 drives the sliding shaft 9 to move upward, the lifting guide plate 19 drives the adjusting sliders 18 to slide upward, pulling the flexible sealing ring 10 to retract upward and decreasing the underwater draft of the outrigger. By controlling the displacement of the linear motor 6, the lifting height of the flexible sealing ring 10 can be precisely controlled, thereby adjusting the draft of the outrigger to any target value, with an adjustment range of 50%-150% of the original depth.

[0054] It is particularly important to emphasize that the movements of the area adjustment unit and the depth adjustment unit are completely independent and do not interfere with each other. When adjusting the area, adjustment slider 17 drives adjustment slider 2 18 to slide radially. Simultaneously, adjustment slider 2 18 slides along the axial guide rail of the lifting guide plate 19, without causing axial movement of the lifting guide plate 19. When adjusting the depth, the lifting guide plate 19 drives adjustment slider 2 18 to slide axially. Simultaneously, adjustment slider 2 18 slides along the square groove at the front end of adjustment slider 17, without causing radial movement of adjustment slider 17. This ingenious structural design enables independent adjustment of both the leg cross-sectional area and draft, while simultaneously achieving synergistic optimization of these two parameters through an intelligent control system. This allows for precise control of the buoy's natural frequency, achieving a dynamic optimal match with the wave excitation frequency.

[0055] The natural frequency of a buoy in the heave direction is determined by its mass, restoring force coefficient, and added mass, and its calculation formula is as follows:

[0056] In the formula: - The natural frequency of the buoy's heave direction, in Hz; - Restoring force coefficient of the buoy in the heave direction, in N / m; - The total mass of the buoy, in kg; -Additional mass of the buoy in the direction of heave, in kg; - The density of seawater, measured in kg / m³ 3 ; - The cross-sectional area of ​​a single variable-length submersible leg, in meters. 2 ; - The current water depth, in meters (m); - The draft of the variable submersible outriggers underwater is measured in meters.

[0057] As can be seen from formula (1), increasing the cross-sectional area of ​​the outriggers... Or increase the draft of the outriggers All of these will increase the added mass of the buoy. Increase, thereby reducing the natural frequency Conversely, it will increase the natural frequency. This invention overcomes the limitation of existing technologies that can only adjust a single parameter, by simultaneously adjusting... and These two parameters enable continuous and precise adjustment of the buoy's natural frequency over a wider frequency range, achieving optimal matching with any wave frequency. Specifically, when a longer wave period and a lower wave frequency are detected, the system simultaneously increases the cross-sectional area of ​​the outriggers. and draft , to make the buoy's natural frequency Consequently, the system reduces the cross-sectional area of ​​the outriggers; when a shorter wave period and an increased wave frequency are detected, the system simultaneously reduces the cross-sectional area of ​​the outriggers. and draft , to make the buoy's natural frequency The buoy's natural frequency can be adjusted to a range of 0.1Hz-1.0Hz through this dual-parameter coordinated adjustment method, covering the common wave frequency range of most sea areas worldwide.

[0058] All detachable connections between components are achieved using stainless steel screws 3. This connection method not only facilitates the assembly, disassembly, and maintenance of the device but also ensures the reliability and sealing of the connections. Seawater-resistant rubber seals are installed at all sealing points, such as the connection between the float housing 4 and the top end cap 2, the connection between the air turbine 1 and the top end cap 2, the mating point between the rotating shaft 8 and the bottom of the float housing 4, and the sealing point of the linear motor output shaft, to prevent seawater from entering the float and damaging electrical components and mechanical structures. Furthermore, the float housing 4 is filled with an appropriate amount of silica gel desiccant to maintain a dry internal environment and prevent electrical components from being damaged by moisture. All electrical wiring inside the float uses waterproof cables and is connected via waterproof connectors. The cable routing is fixed and organized to avoid interference with moving parts.

[0059] The intelligent control system is the core control unit of the buoy in this invention. Its hardware mainly includes an embedded controller, a sea state sensor, a motor driver, a fault detection sensor, a wireless communication module, and a power supply module. The software integrates a leg fault detection module, a sea state data acquisition module, a pre-stored database module, a parameter matching module, an execution drive module, and a feedback optimization module. The intelligent control system is installed in a waterproof control box inside the buoy's outer shell 4. The control box has an IP68 protection rating and is made of 316L stainless steel, with sealant filling inside to effectively prevent seawater and moisture intrusion.

[0060] The outrigger fault detection module monitors the motor operating current and position feedback signals in real time through current sensors and incremental encoders installed on the drive motor 7 and linear motor 6 of each variable submersible outrigger. When a variable submersible outrigger malfunctions, such as motor jamming, transmission mechanism damage, seal breakage, or slider sticking, the corresponding motor operating current will fluctuate abnormally, or the encoder will fail to provide a correct position signal. The outrigger fault detection module can collect these signals in real time and, through a preset fault diagnosis algorithm, promptly determine the outrigger number and fault type, while simultaneously sending the fault information to the embedded controller. The fault diagnosis algorithm employs a fusion diagnosis method based on current and position characteristics, achieving a diagnostic accuracy of over 99%.

[0061] The sea state data acquisition module is electrically connected to the sea state sensors mounted on top of the buoy. These sensors include capacitive wave sensors, pressure depth sensors, and platinum resistance temperature sensors, capable of real-time acquisition of sea state parameters such as water depth, wave height, wave period, and seawater temperature. The capacitive wave sensor has a measurement range of 0.1m-10m and a measurement accuracy of ±0.01m; the pressure depth sensor has a measurement range of 0m-200m and a measurement accuracy of ±0.1m. The sea state data acquisition module automatically adjusts the sensor sampling frequency according to real-time sea conditions to ensure sufficiently dense data acquisition during periods of rapid wave change, while reducing the sampling frequency to minimize system energy consumption during periods of calm wave change. Specifically, when the wave period fluctuation amplitude exceeds a preset threshold of 0.5 seconds, the system increases the sensor sampling frequency to 10Hz; when the wave period fluctuation amplitude is between 0.2 and 0.5 seconds, the system sets the sensor sampling frequency to 5Hz; and when the wave period fluctuation amplitude is less than 0.2 seconds, the system reduces the sensor sampling frequency to 1Hz.

[0062] The pre-stored database module is the core data support for the intelligent control system. It stores the mapping relationship between sea state parameters and optimal outrigger cross-sectional area and optimal draft for different numbers of outriggers that are intact. The pre-stored database module contains three independent sub-databases: the first database, the second database, and the third database. The first database corresponds to the optimal parameter mapping relationship when all four variable-sinking outriggers are intact; the second database corresponds to the optimal parameter mapping relationship when the remaining three variable-sinking outriggers are intact; and the third database corresponds to the optimal parameter mapping relationship when the remaining two variable-sinking outriggers are intact.

[0063] The three sub-databases mentioned above were all pre-established using hydrodynamic simulation software. The establishment process is as follows: First, an accurate three-dimensional hydrodynamic model was established based on the actual structural parameters of the buoy. The model includes the mass and moment of inertia information of the buoy shell 4, the top end cap 2, the variable sinking legs, and all auxiliary structures. Then, for different leg configurations, a large number of frequency domain and time domain simulation calculations were performed under different water depths, wave heights, and wave periods to obtain the heave response amplitude, added mass, damping coefficient, and energy capture efficiency of the buoy under different combinations of leg cross-sectional areas and drafts. Finally, a multi-objective optimization analysis was performed on the simulation results using a genetic algorithm to find the optimal leg cross-sectional area and optimal draft that maximizes the buoy's energy capture efficiency while ensuring the buoy's motion stability under each sea state condition, thereby establishing a one-to-one mapping relationship between sea state parameters and optimal leg parameters. The database covers common sea state ranges from nearshore shallow waters to offshore deep seas, with water depths ranging from 5 meters to 200 meters, wave heights ranging from 0.5 meters to 5 meters, and wave periods ranging from 2 seconds to 12 seconds, which can meet the application needs of most marine environments.

[0064] The parameter matching module matches the real-time sea state parameters acquired by the sea state data acquisition module with the mapping relationship of the corresponding outrigger number in the pre-stored database, quickly finding the optimal outrigger cross-sectional area Si and optimal draft hi under the current sea state. Parameter matching uses a cubic spline interpolation algorithm. When the real-time sea state parameters are not on the discrete sampling points in the database, the system can calculate the corresponding optimal outrigger parameters through cubic spline interpolation, ensuring that the parameter matching accuracy is better than 1%.

[0065] The execution drive module is electrically connected to the servo motor drivers of drive motor 7 and linear motor 6. Based on the optimal adjustment parameters output by the parameter matching module, it generates corresponding PWM control signals to drive the area adjustment units and depth adjustment units of each intact outrigger to operate synchronously, precisely adjusting the cross-sectional area and draft of the outriggers to the target values. The execution drive module employs synchronous control technology to ensure that the adjustment actions of all outriggers start and end simultaneously, with a synchronization error of less than 10ms, preventing the buoy from tilting due to asynchronous adjustment of different outriggers.

[0066] The feedback optimization module records the buoy's actual energy capture efficiency data after each parameter adjustment and compares the actual efficiency with the predicted optimal efficiency in the database. If there is a deviation between the actual and predicted efficiency, the feedback optimization module uses a gradient descent algorithm to analyze the cause of the deviation and iteratively corrects the corresponding mapping relationship in the database based on the deviation value. For example, if, under a certain sea state, the actual energy capture efficiency is lower than the predicted value after adjusting according to the optimal parameters in the database, the system will appropriately adjust the optimal outrigger cross-sectional area and draft for that sea state until the actual efficiency reaches its maximum value. Through this continuous feedback optimization mechanism, the accuracy of the database will continuously improve, and the overall performance of the buoy will gradually improve with the increase of operating time.

[0067] The wireless communication module uses 4G / 5G or BeiDou satellite communication, enabling it to transmit the buoy's operational status, sea state data, power generation data, and fault information to the shore-based monitoring center in real time. It can also receive remote control commands from the shore-based monitoring center, achieving remote monitoring and management of the buoy. The power module consists of a lithium iron phosphate battery pack and a charging management circuit. The lithium battery pack's capacity is designed to be 10Ah-100Ah based on the buoy's power consumption. It is charged by a generator driven by an air turbine, providing power to the entire intelligent control system and actuators. The power module also features overcharge, over-discharge, overcurrent, and short-circuit protection functions to ensure safe battery use.

[0068] The control method for the variable multi-array submerged leg buoy of the present invention specifically includes the following steps: Step S1, Outrigger Status Detection: After the buoy is powered on, the intelligent control system first performs a comprehensive self-check of the operating status of all variable sinking outriggers through the outrigger fault detection module. It sequentially drives the drive motor 7 and linear motor 6 of each outrigger to their limit positions, checks the motor operating current and position feedback signals to determine if each outrigger is functioning correctly, and counts the number of currently intact outriggers. Based on the number of intact outriggers, the system automatically calls the corresponding sub-database in the pre-stored database module: if all four outriggers are intact, the first database is called; if one outrigger malfunctions and cannot operate, the second database is called; if two outriggers malfunction and cannot operate, the third database is called. If the number of intact outriggers is less than two, the system will determine that the buoy cannot operate normally, enter a shutdown protection state, cut off the power to all actuators, and send a serious fault alarm signal to the shore-based monitoring center via the wireless communication module, awaiting maintenance personnel for repair.

[0069] Step S2, Sea State Data Acquisition: The intelligent control system activates the sea state sensor to begin collecting sea state parameters for the current water area. Simultaneously, the sea state data acquisition module calculates the standard deviation of the wave cycle over the past 10 minutes based on the wave cycle data collected in the previous cycle, using this as the wave cycle fluctuation amplitude. Depending on the fluctuation amplitude, the system adaptively adjusts the sensor's sampling frequency: when the fluctuation amplitude is greater than 0.5 seconds, the sampling frequency is set to 10Hz; when the fluctuation amplitude is between 0.2 and 0.5 seconds, the sampling frequency is set to 5Hz; and when the fluctuation amplitude is less than 0.2 seconds, the sampling frequency is set to 1Hz. Through this adaptive sampling frequency adjustment mechanism, the system can minimize energy consumption while ensuring data accuracy.

[0070] Step S3, Safety Verification: The system inputs the collected sea state parameters, such as water depth, wave height, and wave period, into the safety verification module and compares them with the pre-set safe operating range of the equipment. The safe operating range is pre-set based on parameters such as the buoy's structural strength, sealing performance, the pressure resistance rating of electrical components, and the rated power of the generator. For example, the maximum design wave height is 5 meters, and the maximum design current velocity is 3 m / s. If any sea state parameter exceeds the safe operating range, such as a wave height exceeding 5 meters, the system will immediately enter a protection state, suspend all adjustment actions, and drive all actuators to adjust the outriggers to the safe position with the minimum cross-sectional area and shallowest draft to reduce the wave force on the buoy and prevent damage to the device. At the same time, the system sends a sea state anomaly alarm signal to the shore-based monitoring center via the wireless communication module. If all sea state parameters are within the safe operating range, the system enters the parameter matching phase.

[0071] Step S4, Optimal Parameter Matching: The parameter matching module inputs the real-time collected water depth, wave height, and wave period data into the sub-database called in Step S1. It then uses a cubic spline interpolation algorithm to calculate the optimal leg cross-sectional area Si and optimal draft hi for maximizing the buoy's energy capture efficiency under the current sea state. Simultaneously, the system will appropriately adjust the optimal parameters based on the buoy's current load to ensure the buoy maintains high power generation efficiency under different loads.

[0072] Step S5, Dual-Parameter Coordinated Adjustment: The system compares the matched optimal outrigger cross-sectional area Si and optimal draft hi with the buoy's current outrigger cross-sectional area S and current draft h. If the difference between Si and S is less than 1% and the difference between hi and h is less than 1%, the system considers the current parameters to be optimal and maintains the existing outrigger parameters unchanged. If the difference between Si and S is greater than 1% or the difference between hi and h is greater than 1%, the drive module generates the corresponding motor control signal, simultaneously driving the area adjustment unit and depth adjustment unit of all intact outriggers to operate synchronously, adjusting the outrigger cross-sectional area to Si and the outrigger draft to hi. By simultaneously adjusting the two parameters of outrigger cross-sectional area and draft, the system can precisely control the buoy's natural frequency, achieving a dynamic optimal match with the current wave excitation frequency, thereby maximizing the buoy's energy capture efficiency.

[0073] Step S6, Feedback Optimization: The system records the buoy's average energy capture efficiency data within 30 minutes after the parameter adjustment and compares the actual average efficiency with the predicted optimal efficiency in the database. If the deviation between the actual and predicted efficiency exceeds 5%, the feedback optimization module will initiate a parameter optimization program, conducting multiple parameter tests within a small range near the current parameters to find the optimal parameter that maximizes the actual efficiency, and updating the corresponding position in the database with this parameter. Through this continuous online feedback optimization mechanism, the database can continuously adapt to changes in actual sea conditions, improving the accuracy of parameter matching.

[0074] Step S7, Periodic Cycle: The system periodically repeats steps S1 to S6 according to an adaptively set time interval to achieve continuous tracking and dynamic response to sea state changes. The time interval is also adaptively adjusted according to sea state changes: when sea state changes drastically and the wave period fluctuation amplitude is greater than 0.5 seconds, the time interval is set to 1 minute; when sea state changes are relatively gentle and the wave period fluctuation amplitude is between 0.2 and 0.5 seconds, the time interval is set to 5 minutes; when sea state is very stable and the wave period fluctuation amplitude is less than 0.2 seconds, the time interval is set to 10 minutes. Through this adaptive periodic adjustment, the system can respond promptly to changes in sea state and always keep the buoy in an optimal energy capture state.

[0075] Furthermore, when any one or two variable outriggers of the buoy suddenly fail during operation, the outrigger fault detection module can detect the fault signal within one second and trigger the system to perform emergency processing. The system first immediately stops all ongoing adjustments, then re-detects the number of remaining intact outriggers and automatically switches to the corresponding sub-database. Subsequently, the system re-matches and adjusts parameters according to the new database, enabling the buoy to continue operating in degraded mode. Experimental results show that when one outrigger fails, the buoy's power generation still reaches over 75% of the rated power; when two outriggers fail, the buoy's power generation still reaches over 50% of the rated power, effectively preventing the entire device from shutting down due to a single outrigger failure and significantly improving the overall reliability and availability of the system.

[0076] To verify the performance of the buoy of this invention, the inventors conducted systematic simulation and water tank model experiments. Figure 9 The figure shows the relationship between the outrigger diameter and the diffraction response value. As can be seen from the figure, the diffraction response value of the buoy increases significantly with the increase of the outrigger diameter, indicating that the increase of the cross-sectional area of ​​the outrigger can effectively improve the added mass of the buoy, thereby reducing the natural frequency of the buoy. This is completely consistent with the theoretical analysis results of formula (1). Figure 10 The figure shows the relationship between the change in outrigger draft and the change in underwater air chamber volume. As can be seen from the figure, even in the extreme case where the outrigger draft changes by 50%, the change in underwater air chamber volume can still be controlled within 10%, exhibiting a gentle, non-linear growth trend without significant amplification or abrupt changes. This result strongly demonstrates that the structural design of this invention has a good suppressive and buffering effect on air chamber volume changes. The change amplitude is much smaller than the structural adjustment amplitude, and therefore insufficient to cause significant fluctuations in the air chamber compression ratio. This effectively solves the key technical problem in the prior art where adjusting the outrigger draft causes the air chamber compression ratio to deviate from the optimal design condition of the air turbine, thus reducing the efficiency of the power generation system.

[0077] Pool experiments show that, compared to traditional fixed-parameter buoys, the variable multi-array submerged leg buoy of this invention can broaden the energy capture bandwidth by more than three times, maintaining an energy capture efficiency of over 20% within a wave period range of 3 to 10 seconds. Furthermore, compared to buoys that can only adjust a single parameter, the dual-parameter coordinated adjustment buoy of this invention improves the average energy capture efficiency by more than 28% under the same sea conditions. In addition, due to the adoption of multi-unit redundancy design and fault degradation operation mechanism, the mean time between failures (MTBF) of the buoy of this invention reaches over 15,000 hours, more than twice that of existing technologies, significantly reducing maintenance costs and downtime losses in marine environments.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention. For example, the number of variable submersible outriggers can be adjusted to 2, 3, or other numbers according to actual needs; the number of adjusting slider assemblies can be increased or decreased between 8 and 32 depending on the size of the outriggers and the adjustment accuracy requirements; the material and structure of the flexible sealing ring can be optimized according to different marine environments; the hardware configuration and software algorithm of the intelligent control system can also be improved accordingly without departing from the core idea of ​​the present invention. All these equivalent transformations and modifications should fall within the scope of protection of the present invention.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A buoy with variable multi-array submersible legs, characterized in that, Includes a floating body shell (4), a top end cap (2), an air turbine (1), at least two variable sinking legs, a dual-parameter adjustment actuator, and an intelligent control system; The floating body shell (4) and the top end cap (2) enclose each other to form a sealed inner cavity air chamber. The air turbine (1) is installed at the through hole of the top end cap (2) and communicates with the inner cavity air chamber. At least two variable sinking legs are evenly distributed along the bottom circumference of the floating body shell (4), and each variable sinking leg is fixedly connected to the floating body shell (4) through a leg connector (14); The dual-parameter adjustment actuator is integrated inside each variable submersible leg and is used to synchronously adjust the cross-sectional area and underwater draft of the variable submersible leg. The intelligent control system is electrically connected to the sea state sensor and the dual-parameter adjustment actuator, respectively. It is used to drive the dual-parameter adjustment actuator to adjust the cross-sectional area and draft of the outriggers in coordination according to the real-time sea state and the number of intact variable sinking outriggers, so that the natural frequency of the buoy and the wave excitation frequency are dynamically matched. The number of the variable submersible outriggers is 2, 3 or 4, and each variable submersible outrigger includes a disc base (15) and a flexible sealing ring (10) wrapped around the outside of the disc base (15); the dual-parameter adjustment actuator adjusts the cross-sectional area of ​​the outrigger by driving the radial expansion / contraction of the flexible sealing ring (10), and adjusts the underwater draft of the outrigger by driving the axial lifting of the flexible sealing ring (10); The area adjustment unit of the dual-parameter adjustment actuator includes a drive motor (7), a bevel gear pair, a rotating shaft (8), a rotating wheel (16), and several sets of adjustment slider assemblies; The drive motor (7) is fixed on the drive motor base (13) inside the floating body shell (4). The bevel gear pair includes a first bevel gear (12) and a second bevel gear (11) that mesh with each other. The second bevel gear (11) is fixedly connected to the output shaft of the drive motor (7). The first bevel gear (12) is fixedly connected to the upper end of the rotating shaft (8). The lower end of the rotating shaft (8) is fixedly connected to the wheel (16). Several sets of adjusting slider assemblies are evenly distributed along the circumference of the disc base (15). Each set of adjusting slider assemblies includes adjusting slider one (17) and adjusting slider two (18). The disc base (15) has radial grooves corresponding to the number of adjusting slider one (17). Adjusting slider one (17) is slidably installed in the radial groove. Its end is pointed and abuts against the outer circumferential surface of the rotating wheel (16). Its front end has an axial groove. Adjusting slider two (18) is slidably embedded in the axial groove. The outer ends of the first adjusting slider (17) and the second adjusting slider (18) are fixed to the inner side of the flexible sealing ring (10). When the rotating wheel (16) rotates, it pushes the first adjusting slider (17) to slide along the radial groove, causing the second adjusting slider (18) and the flexible sealing ring (10) to expand or contract radially.

2. The buoy with variable multi-array submersible legs according to claim 1, characterized in that, The depth adjustment unit of the dual-parameter adjustment actuator includes a linear motor (6), a sliding shaft (9), and a lifting guide plate (19); The linear motor (6) is fixed on the linear motor mounting base (5), and the linear motor mounting base (5) is supported and fixed inside the floating body shell (4) by the protrusion of the drive motor base (13); The rotating shaft (8) is a hollow shaft, and the sliding shaft (9) is coaxially inserted in the central through hole of the rotating shaft (8) and slides in cooperation with the rotating shaft (8). The upper end of the sliding shaft (9) is fixedly connected to the output end of the linear motor (6), and the lower end is fixedly connected to the center of the lifting guide plate (19). The outer circumferential surface of the lifting guide plate (19) is provided with an axial guide rail corresponding to the number of adjusting sliders (18). The inner side of the adjusting sliders (18) is slidably embedded in the axial guide rail. When the linear motor (6) drives the sliding shaft (9) and the lifting guide plate (19) to move axially, it drives the adjusting sliders (18) to slide along the axial groove, thereby driving the flexible sealing ring (10) to rise and fall axially to adjust the draft of the outrigger.

3. The buoy with variable multi-array submersible legs according to claim 2, characterized in that, Each variable submersible outrigger has 16 radial grooves on its disc base (15), corresponding to 16 sets of adjusting slider assemblies; the outer circumference of the lifting guide plate (19) is provided with 30 axial guide rails, and each adjusting slider (18) is correspondingly embedded in one axial guide rail; all detachable connections between components are achieved by screws (3).

4. The buoy with variable multi-array submersible legs according to claim 1, characterized in that, The intelligent control system includes an outrigger fault detection module, a sea state data acquisition module, a pre-stored database module, a parameter matching module, an execution drive module, and a feedback optimization module. The outrigger failure detection module is used to detect the number of intact variable submersible outriggers in real time. The sea state data acquisition module is electrically connected to the sea state sensor and is used to collect data on the current water depth, wave height and wave period of the water area. The pre-stored database module stores the mapping relationship between sea state parameters and optimal outrigger cross-sectional area and optimal draft for different numbers of intact outriggers; The parameter matching module is used to match real-time sea state parameters with a pre-stored database and output the optimal adjustment parameters; The execution drive module is used to drive the action of the dual-parameter adjustment actuator according to the optimal adjustment parameters; The feedback optimization module is used to record the energy capture efficiency after each parameter adjustment and iteratively optimize the mapping relationship in the pre-stored database.

5. The buoy with variable multi-array submersible legs according to claim 4, characterized in that, The pre-stored database module includes three independent databases: a first database, a second database, and a third database, which correspond to the optimal parameter mapping relationships when 4, 3, and 2 variable submersible outriggers are intact, respectively. The mapping relationships are pre-established through AQWA simulation and cover sea state ranges with different water depths, wave heights, and wave periods.

6. A control method for a variable multi-array submerged outrigger buoy, characterized in that, Includes the following steps: S1. Outrigger Status Detection: The intelligent control system detects the number of intact variable submersible outriggers through the outrigger fault detection module and calls the optimal parameter mapping library corresponding to the number of outriggers in the pre-stored database. S2. Sea State Data Acquisition: The intelligent control system automatically adjusts the sampling frequency of the sea state sensor according to the real-time sea state to acquire data on the water depth, wave height and wave period of the current water area; S3. Safety Verification: Input the collected sea state parameters into the system for multi-parameter safety verification. If any parameter exceeds the safe operating range of the equipment, the system will enter protection mode and suspend operation; if all parameters are within the safe range, the system will enter the parameter matching stage. S4. Optimal parameter matching: Based on real-time sea state parameters, the optimal outrigger cross-sectional area Si and optimal draft hi under the current sea state are obtained by matching from the called optimal parameter mapping library; S5. Dual-parameter coordinated adjustment: The optimal parameters Si and hi are compared with the current cross-sectional area of ​​the buoy's outriggers S and the current draft h. If there is a difference, the dual-parameter adjustment actuator is driven to synchronously adjust the cross-sectional area of ​​the outriggers to Si and the draft to hi, so that the buoy's natural frequency matches the wave excitation frequency in real time.

7. The control method for a variable multi-array submerged outrigger buoy according to claim 6, characterized in that, In step S2, the intelligent control system adaptively adjusts the sampling frequency according to the fluctuation amplitude of the wave cycle: when the fluctuation amplitude of the wave cycle is greater than the preset threshold, the sampling frequency is increased; when the fluctuation amplitude of the wave cycle is less than the preset threshold, the sampling frequency is decreased.

8. The control method for a variable multi-array submerged outrigger buoy according to claim 6, characterized in that, It also includes the following steps: S6 Feedback Optimization: The system records the energy capture efficiency data after each parameter adjustment, forming a feedback data stream, and periodically iterates and optimizes the optimal parameter mapping relationship in the pre-stored database; S7 Periodic Cycle: The system periodically repeats steps S1 to S6 according to an adaptively set time interval to achieve continuous tracking and dynamic response to changes in sea state. When any one or two of the variable sinking outriggers fail and cannot be adjusted, the system automatically calls the optimal parameter mapping library corresponding to the number of remaining intact outriggers to maintain the buoy's degraded operation.

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