Self-powered buoy based on fluid energy capture by flow-induced vibration and working method

Abstract

The application belongs to the field of ocean monitoring equipment energy supply and buoy adaptation working condition, and discloses a self-powered buoy based on fluid-induced vibration fluid kinetic energy capture and a working method. The buoy cooperates with the depth of the energy supply system and the float-sink system: on the one hand, the flow-induced vibration technology is deeply integrated with the buoy, the circumferential uniform arrangement of the cylindrical vibrator responds to the sea current in different directions, the vortex shedding effect is used when the sea current flows through the vibrator to drive the deformation of the piezoelectric sheet, the mechanical energy is converted into electrical energy, no additional driving device is needed and the starting flow rate is low, and the problem of single vibrator direction limitation is solved; on the other hand, the float-sink regulation system dynamically adjusts the draft depth based on sensor monitoring data, and realizes intelligent switching of the working state and the charging state. The application has strong sea condition adaptability and low maintenance cost, can ensure long-term stable energy supply and reliable monitoring of the buoy, and effectively overcomes the defects of insufficient energy supply of the traditional buoy, disconnection of the float-sink and energy supply system and limited energy capture direction.

Description

Technical Field

[0001] This invention belongs to the technical field of marine monitoring equipment power supply and buoy adaptation, and particularly relates to a self-powered buoy and its working method based on fluid kinetic energy capture by flow-induced vibration. Background Technology

[0002] In fields such as marine environmental monitoring, marine resource exploration, and marine ecological protection, marine monitoring equipment requires long-term stable operation, placing extremely high demands on the real-time nature of data acquisition and the continuity of power supply. As the core monitoring carrier, the reliability of the power supply system of buoys directly determines the effectiveness of monitoring work. Currently, traditional buoys mainly rely on battery energy storage or shore-based power supply. However, with the development of clean and renewable energy technologies, ocean current energy, due to its stable energy density and sustainable availability, has become an important breakthrough for buoy self-powering. Through the phenomenon of flow-induced vibration, the fluid kinetic energy of ocean currents can be converted into structural vibration energy, and combined with the positive piezoelectric effect of piezoelectric materials, energy capture and power supply can be achieved. This technical approach has become a key research direction for solving the problem of buoy power supply.

[0003] Existing current-energy-based buoys are mainly divided into three categories: turbine-driven, wave-driven, and oscillating water column-driven. Turbine-driven buoys rely on rotating blades to generate electricity, requiring a certain flow velocity to start, and cannot work in low-speed ocean currents. Wave-driven buoys rely on the up-and-down movement of waves and must operate on a horizontal plane, making them prone to collisions with ships and causing power supply fluctuations due to wave instability. Oscillating water column buoys generate electricity by the vibration of air within a column driven by ocean waves, and are similarly limited to horizontal operation, fundamentally conflicting with the buoy's need to flexibly adapt to different sea conditions. In addition, traditional buoys suffer from the drawback of relying on batteries or shore-based power supply, requiring regular battery replacement or the laying of shore-based power lines, resulting in high maintenance costs. Furthermore, batteries have limited energy storage, and shore-based power supply is limited by distance, easily leading to unstable power supply problems and making them unsuitable for complex sea conditions such as typhoons and giant waves.

[0004] More critically, existing buoys generally suffer from a core deficiency: their power supply and buoyancy systems are independent of each other, lacking a collaborative optimization mechanism. On the one hand, buoy buoyancy adjustments are mostly fixed modes or driven by a single monitoring need, failing to dynamically adjust in conjunction with ocean current energy capture efficiency, making it difficult to maximize the energy capture effect of flow-induced vibrations. On the other hand, the lack of precise monitoring methods for key ocean current parameters (such as current velocity and turbulence) makes it impossible to accurately characterize ocean current conditions at different depths, making it difficult to ensure that the buoy is always in the ideal working layer of "optimal energy capture efficiency + minimal environmental disturbance." Furthermore, some buoys employ single-oscillator or non-omnidirectional layout designs, resulting in insufficient adaptability to ocean currents in different directions and the existence of energy capture blind spots, further limiting the integrity and stability of energy capture.

[0005] Although flow-induced vibration technology has the advantages of low flow rate start-up and no need for a specific working plane, and has been initially applied in the field of buoy power supply, the existing technology has failed to form a deep synergy with buoyancy control and parameter monitoring, and has not yet solved the core problems of the disconnect between power supply and buoyancy, and the large impact of working condition fluctuations on energy capture efficiency. Summary of the Invention

[0006] This invention provides a self-powered buoy and its operating method based on fluid kinetic energy capture by flow-induced vibration. Using this buoy, the power supply system and the buoyancy system can be deeply coordinated and omnidirectionally captured. It not only has strong sea state adaptability, low maintenance cost and stable power supply, but also enables efficient omnidirectional energy capture and stable monitoring of the buoy under different sea states.

[0007] To achieve the above objectives, the present invention employs the following technical content: A self-powered buoy based on fluid kinetic energy capture by flow-induced vibration, comprising a shell; The top of the outer shell is equipped with a signal transceiver device, which is used to transmit and receive power supply data, monitoring data, and ocean current parameters; the ocean current parameters include the incoming current velocity and the intensity of water flow disturbance. The top of the outer shell is equipped with a multi-oscillator flow-induced piezoelectric energy harvesting system and a buoyancy control system; the multi-oscillator flow-induced piezoelectric energy harvesting system is connected to the transceiver signal device and the buoyancy control system respectively. An energy storage device is installed inside the outer shell; the energy storage device is connected to a multi-oscillator flow-induced piezoelectric energy harvesting system, a transceiver signal device, and a buoyancy control system, respectively. The multi-oscillator flow-induced vibration piezoelectric energy harvesting system includes at least 3 sets of energy harvesting components; each set of energy harvesting components is evenly arranged along the bottom circumferential direction of the shell. The energy harvesting component includes a piezoelectric sheet connected to the outer shell; the piezoelectric sheet is connected to a cylindrical oscillator; each cylindrical oscillator is capable of capturing the mechanical energy of the ocean current in the full circumference, so that the piezoelectric sheet deforms and converts the mechanical energy into electrical energy; The outer side of the shell is equipped with multiple flow velocity sensors and multiple turbulence intensity sensors. Each flow velocity sensor and each turbulence intensity sensor corresponds to a set of energy harvesting components. They are evenly arranged along the circumference of the shell and are directly opposite the cylindrical oscillator. The flow velocity sensor is used to monitor the incoming flow velocity in real time, and the turbulence intensity sensor is used to monitor the water flow disturbance intensity in real time. Both are electrically connected to the signal transceiver device and the buoyancy control system. The buoyancy control system is used to automatically adjust the buoy's draft based on power supply data, monitoring data, and ocean current parameters collected by sensors, enabling intelligent switching between working and charging states. This allows the multi-oscillator flow-induced vibration piezoelectric energy harvesting system to adjust the flow-induced vibration intensity, or / and allows the transceiver device to adjust the monitoring range.

[0008] Furthermore, a rectification control circuit is also provided inside the outer shell; the rectification control circuit is connected to the energy storage device, the transceiver device, the buoyancy control system, the flow velocity sensor and the turbulence sensor respectively, and is used to rectify and control the electrical energy passing through the outer shell, and transmit the rectified electrical energy to the energy storage device, the transceiver device, the buoyancy control system, the flow velocity sensor and the turbulence sensor.

[0009] Furthermore, the outer casing is made of waterproof material; the transceiver device is an antenna; the antenna is connected to the top of the outer casing via a waterproof connector.

[0010] Furthermore, the piezoelectric element is connected to the outer shell and the cylindrical vibrator via angle steel; the angle steel is made of metal.

[0011] Furthermore, the piezoelectric sheet is made of piezoelectric ceramic or piezoelectric polymer material and has a resin coating on its surface; each piezoelectric sheet is tightly attached to the connection area between the angle steel and the outer shell and the connection area between the angle steel and the cylindrical oscillator.

[0012] Furthermore, the buoyancy control system includes an electric winch, a cable reel, and a cable. The electric cable winch is fixed to the housing, and its output end is connected to the cable reel via a key connection. One end of the cable is wound around the cable shaft, and the other end is used to connect to the seabed anchoring device; The electric cable winch is connected to the multi-vibrator flow-induced piezoelectric energy harvesting system and the energy storage device, respectively.

[0013] Furthermore, the body of the electric cable winch is located inside the outer casing.

[0014] Furthermore, each of the energy-harvesting components is vertically connected to the bottom of the housing.

[0015] A method for operating a self-powered buoy based on fluid kinetic energy capture by flow-induced vibration, wherein the self-powered buoy based on fluid kinetic energy capture by flow-induced vibration comprises: The transceiver device transmits and receives power supply data, monitoring data, and ocean current parameters collected by sensors; By using a cylindrical oscillator to capture the mechanical energy of ocean currents in the full circumference, the piezoelectric element is deformed, converting the mechanical energy into electrical energy. The buoyancy control system automatically adjusts the buoy's draft based on power supply data, monitoring data, incoming flow velocity collected by the flow velocity sensor, and water flow disturbance intensity obtained by the turbulence intensity sensor. This enables intelligent switching between working and charging states, allowing the multi-oscillator flow-induced vibration piezoelectric energy harvesting system to adjust the flow-induced vibration intensity, or / and allowing the transceiver signal device to adjust the monitoring range.

[0016] Furthermore, the automatic adjustment of the buoy's draft by the buoyancy control system based on power supply data, monitoring data, and ocean current parameters collected by sensors includes: Working status: According to the monitoring task requirements, the length of the cable is adjusted through the buoyancy control system to keep the buoy at the preset working depth; Charging Status: If the stored energy in the power supply data is determined to be lower than the preset stored energy value, the incoming flow velocity is obtained through a flow velocity sensor. Combined with the natural frequency and diameter of the cylindrical oscillator, a reduced velocity is calculated. Simultaneously, the water flow disturbance intensity is obtained from a turbulence intensity sensor. The optimal draft is calculated using the optimal depth decision formula. The buoyancy control system adjusts the cable deployment and retraction to keep the buoy at the optimal depth, thereby increasing the intensity of flow-induced vibration. The specific calculation formula for the reduced velocity is as follows:

[0017] In the formula, To reduce the speed; For depth The actual incoming flow velocity at the location; is the natural frequency of the cylindrical oscillator; D is the diameter of the cylindrical oscillator; The specific formula for calculating the optimal draft is as follows:

[0018] In the formula, The optimal draft for the buoy; 、 For different weighting coefficients; The baseline optimal depth function corresponding to the reduced velocity; This is the depth correction function corresponding to the turbulence intensity; If the monitoring range in the monitoring data is determined to be less than the preset monitoring range, the draft is increased through the buoyancy control system so that the signal receiving and transmitting device can increase the monitoring range.

[0019] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a self-powered buoy based on fluid kinetic energy capture using flow-induced vibration. Through the synergistic design of flow-induced vibration technology and a buoyancy control system, when ocean currents flow past a cylindrical oscillator, the alternating vortices behind it generate periodic forces that drive the oscillator to vibrate, thereby causing piezoelectric elements to deform and generate electricity. Simultaneously, through precise monitoring data from flow velocity and turbulence sensors, the buoyancy control system dynamically adjusts the draft, ensuring that the vortex-induced vibration efficiency is within the optimal range while reducing the impact of water flow disturbances on energy capture stability, achieving a deep integration of energy supply and buoyancy. This technology can be stably started at low flow velocities and does not require a specific working plane, perfectly adapting to the marine conditions of buoys. The buoy responds omnidirectionally to ocean currents in different directions through circumferentially arranged cylindrical oscillators, and the buoyancy control system dynamically adjusts the draft to optimize vibration intensity, achieving the dual goals of efficient capture of ocean current mechanical energy and optimized monitoring range. This overcomes the shortcomings of traditional buoys, such as insufficient power supply, poor sea state adaptability, and disconnect between power supply and buoyancy control systems, ensuring long-term stable monitoring and reducing maintenance costs.

[0020] Preferably, in this invention, a rectifier control circuit is added and connected between the energy storage device and other systems for rectifying and distributing electrical energy. The rectifier control circuit efficiently converts the alternating current generated by the piezoelectric energy harvesting system into stable direct current and distributes it to the energy storage device, transceiver, control system, and sensors, avoiding voltage fluctuations or energy loss. This improves energy conversion efficiency and storage reliability, enhances the system's power supply stability under complex sea conditions, reduces maintenance requirements, and overcomes the problem of uneven power supply caused by traditional power supply modes.

[0021] Preferably, in this invention, the outer shell is made of waterproof material, and the signal transceiver is an antenna connected via a waterproof connector. The waterproof design and sealed connector protect the internal components and sensors from seawater corrosion and the impact of typhoons and waves, ensuring that antenna signal transmission and sensor data acquisition are unaffected by moisture or environmental interference. This significantly enhances the buoy's durability and environmental adaptability, guarantees the reliability of signal transmission and data monitoring, extends its service life, and enables stable operation under harsh sea conditions.

[0022] Preferably, in this invention, the piezoelectric element is connected to the outer shell and the cylindrical oscillator via a metal angle steel. The metal angle steel provides rigid support, disperses mechanical stress, and ensures that the piezoelectric element undergoes uniform deformation when the oscillator vibrates, avoiding fatigue fracture caused by stress concentration. This optimizes the structural strength and vibration transmission efficiency of the energy harvesting component, improves energy conversion efficiency and system reliability, and reduces maintenance frequency.

[0023] Preferably, in this invention, the piezoelectric element is made of piezoelectric ceramic or polymer material, with a resin coating on its surface, and is tightly fitted to the connection area. The coating protects against seawater corrosion and biofouling, the material selection enhances the piezoelectric effect, and the tight fit ensures efficient conversion of mechanical energy into electrical energy without leakage. This improves energy capture efficiency and environmental tolerance, extends component life, ensures long-term stable operation, and adapts to complex sea conditions such as salt spray and surges.

[0024] Preferably, in this invention, the buoyancy control system comprises an electric winch, a cable reel, and a cable assembly, connecting the energy harvesting system, the energy storage device, and the sensor data transmission module. The electric winch responds to real-time data to control the cable winding and unwinding, precisely adjusting the buoy's draft to keep the oscillator always at the optimal current layer. This achieves dynamic optimization of the draft, improves the efficiency of current energy harvesting and the adaptability of the monitoring range, and enhances the system's stability under changes in current velocity and complex disturbances.

[0025] Preferably, in this invention, the electric winch body is housed inside the outer casing. This internal installation isolates the buoy from external seawater and mechanical impacts, protecting critical control components from corrosion and physical damage. This design improves the reliability and safety of the buoyancy control system, reduces the failure rate, and enhances the buoy's long-term operational capability in extreme environments such as typhoons or giant waves.

[0026] Preferably, in this invention, each group of energy-harvesting components is vertically connected to the bottom of the outer shell. Vertical arrangement maximizes the contact area between the ocean current and the oscillator, ensuring efficient vibration induced by the circumferential ocean current, avoiding energy loss from inclined connections. This enhances the omnidirectional ocean current energy harvesting efficiency and response sensitivity, improves energy output at low flow rates, and further addresses the insufficient coverage problem of existing designs.

[0027] Preferably, in this invention, multiple flow velocity sensors and multiple turbulence intensity sensors are provided, each corresponding to a cylindrical oscillator, and are evenly distributed on the outer side of the outer shell, directly opposite the cylindrical oscillator. The sensors are electrically connected to the signal transceiver and the buoyancy control system. The flow velocity sensors are used to monitor the incoming current velocity in real time, providing basic data for calculating the reduced velocity; the turbulence intensity sensors are used to monitor the intensity of water flow disturbance. Together, they achieve accurate characterization of ocean current conditions, providing a decision-making basis for the buoyancy control system, realizing synergistic optimization between the power supply system and the buoyancy system, and overcoming the shortcomings of traditional buoys that blindly adjust their buoyancy.

[0028] This invention also provides a method for operating a self-powered buoy based on fluid kinetic energy capture using flow-induced vibration. Based on the aforementioned self-powered buoy based on fluid kinetic energy capture using flow-induced vibration, this method transmits power supply data, monitoring data, and ocean current parameters collected by sensors in real time via a transceiver device. It utilizes multiple sets of circumferentially uniformly arranged cylindrical oscillators to capture ocean current mechanical energy from all directions, driving piezoelectric elements to deform and generate electricity. Based on the power supply data, monitoring data, and ocean current parameters, it automatically triggers a buoyancy control system to adjust the buoy's draft, achieving intelligent switching between "working state" and "charging state": In working state, the buoy adjusts the cable length according to different task requirements through the buoyancy control system to maintain a preset working depth, ensuring the monitoring range meets task requirements; in charging state, the buoy integrates the incoming flow velocity monitored by the current velocity sensor and the disturbance intensity data monitored by the turbulence intensity sensor, calculating the optimal draft using a formula to ensure that the vortex-induced vibration efficiency of the cylindrical oscillators is in the optimal range and the water flow disturbance is minimized.

[0029] Multiple oscillators work in concert to cover all directions of ocean currents, overcoming the energy capture blind spots of single-oscillator designs. They maintain efficient energy conversion in low-velocity or non-axial currents, while dynamic adjustment of draft ensures that the oscillators are always at the optimal depth of ocean current action, adapting to changes in current velocity and wave height fluctuations, thereby improving energy capture efficiency and system stability. This method achieves deep synergy between the power supply system and the buoyancy system, enhancing adaptability to complex sea conditions, significantly reducing maintenance costs, ensuring continuous and stable power supply and long-term reliable monitoring, and completely solving the operational defects caused by unstable power supply, insufficient energy capture, and fixed draft of traditional buoys.

[0030] Preferably, in this invention, based on real-time power supply data, monitoring data, and ocean current parameters collected by sensors, including the incoming flow velocity monitored by the velocity sensor and the water flow disturbance intensity monitored by the turbulence intensity sensor, the closed-loop optimization of the floating and sinking state is achieved through the formula calculation of "accurate calculation of reduced velocity - turbulence intensity correction - optimal depth decision", ensuring that the cylindrical oscillator can be in the optimal range of vortex-induced vibration efficiency while avoiding the influence of highly disturbed water flow. Preferably, in this invention, when the stored energy is low, the system switches to charging mode, calculating the optimal depth using sensor data to enhance vibration intensity; when the monitoring range needs adjustment, it switches to working mode, adjusting the depth using a buoyancy control system to expand the monitoring range; data-driven decision-making dynamically balances energy harvesting and monitoring needs, adapting to changes in ocean current velocity and wave height. This intelligently optimizes system performance, improves energy harvesting efficiency and monitoring reliability under complex sea conditions, and enables long-term unattended stable operation. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a self-powered buoy based on fluid kinetic energy capture by flow-induced vibration, provided in an embodiment of the present invention. Figure 2This is a schematic diagram of the structure of the energy harvesting component provided in an embodiment of the present invention; Figure 3 The diagram illustrates the principle of flow-induced vibration energy harvesting in an embodiment of the present invention, wherein (A) represents a cylindrical oscillator in one phase of vibration; and (B) represents a cylindrical oscillator in another phase of vibration. Figure 4 This is a schematic diagram of omnidirectional energy harvesting coverage provided in an embodiment of the present invention; Figure 5 is a schematic diagram comparing the working state and charging state of the buoy provided in the embodiment of the present invention, wherein (A) is a schematic diagram of the structure of the buoy in the working state; and (B) is a schematic diagram of the structure of the buoy in the charging state.

[0032] Figure label: 1. Antenna; 2. Housing; 3. Piezoelectric element; 4. Cylindrical vibrator; 5. Flow velocity sensor; 6. Turbulence sensor; 7. Cable reel; 8. Electric cable winch; 9. Cable; 10. Angle steel; 11. Screw. Detailed Implementation

[0033] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the following specific embodiments provide a further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0036] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0037] Combination Figure 1 and Figure 2 As shown, in order to solve the problems existing in the current technology, this embodiment provides a self-powered buoy based on fluid kinetic energy capture by flow-induced vibration, and the specific structure is as follows: The device includes an outer casing 2, which is made of waterproof material, specifically engineering plastic or stainless steel. The entire casing is waterproof, and an energy storage device and rectifier control circuit are sealed inside. The energy storage device uses a battery. A transceiver device is located on the top of the casing 2. This transceiver device is used to transmit and receive power supply data, monitoring data, and ocean current parameters, and also has remote control capabilities. It preferably uses an antenna 1, which is fixed to the top of the casing 2 via a waterproof connector to ensure waterproof performance. The top of the outer casing 2 is also equipped with a multi-vibrator flow-induced vibration piezoelectric energy harvesting system and a buoyancy control system. The multi-vibrator flow-induced vibration piezoelectric energy harvesting system is connected to the transceiver signal device and the buoyancy control system respectively. The energy storage device is connected to the multi-vibrator flow-induced vibration piezoelectric energy harvesting system, the transceiver signal device, the buoyancy control system, the flow velocity sensor 5, and the turbulence sensor 6 respectively, providing power support for each component. The rectification control circuit is connected to the energy storage device, the transceiver signal device, the buoyancy control system, the flow velocity sensor 5, and the turbulence sensor 6 respectively, and is used to rectify and control the electrical energy generated by the multi-vibrator flow-induced vibration piezoelectric energy harvesting system, and transmit the rectified electrical energy to the energy storage device for storage, or directly supply the transceiver signal device, the buoyancy control system, the flow velocity sensor 5, and the turbulence sensor 6.

[0038] For example, the multi-oscillator flow-induced vibration piezoelectric energy harvesting system includes at least 3 sets of energy harvesting components. In this embodiment, three sets of energy harvesting components are used. Each set of energy harvesting components is evenly distributed along the bottom circumference of the outer shell 2, specifically at 120° intervals, to ensure full circumferential energy harvesting capability. As shown in Figure 2, each energy harvesting assembly includes a piezoelectric element 3 and a cylindrical oscillator 4. The piezoelectric element 3 is connected to the outer shell 2 and the cylindrical oscillator 4 respectively via an angle steel 10. The angle steel 10 is made of metal, and its two branches are fastened to the outer side of the outer shell 2 and the end of the cylindrical oscillator 4 respectively by screws 11 to achieve a stable mechanical connection. The piezoelectric element 3 is made of piezoelectric ceramic or piezoelectric polymer, and its surface is coated with a resin coating, specifically a uniform epoxy resin coating. Each piezoelectric element 3 is tightly attached to the connection area between the angle steel 10 and the outer shell 2 and the connection area between the angle steel 10 and the cylindrical oscillator 4, ensuring that the cylindrical oscillator 4 can drive the angle steel 10 to vibrate synchronously when it vibrates, thereby causing the piezoelectric element 3 to generate effective bending strain. As shown in Figure 3, specifically in Figures (A) and (B), each cylindrical oscillator 4 can capture the mechanical energy of the ocean current in the entire circumference. When the ocean current flows past the buoy from any direction, thanks to the omnidirectional arrangement of the three sets of cylindrical oscillators 4 along the circumference of the outer shell 2, at least one cylindrical oscillator 4 can be in the optimal flow-around region without flow field obstruction. Behind it, vortices will alternately fall off, generating periodic lift and drag, driving the cylindrical oscillator 4 to vibrate in the direction perpendicular to the ocean current. When the cylindrical oscillator 4 vibrates, it drives the corresponding connected angle steel 10 to move synchronously, causing the tightly fitted piezoelectric sheet 3 to bend and deform with the angle steel 10. The piezoelectric sheet 3 uses the positive piezoelectric effect to convert the mechanical energy in this process into electrical energy, providing a basis for powering the various components of the buoy.

[0039] The buoyancy control system includes an electric winch 8, a cable reel 7, and a cable 9. The electric winch 8 is a miniature waterproof type, with its body housed inside and fixed to the outer shell 2. The electric winch 8 is connected to a multi-vibrator flow-induced piezoelectric energy harvesting system, an energy storage device, and a signal transceiver device, and is powered and controlled by the circuitry inside the outer shell 2. The output end of the electric winch 8 is connected to the cable reel 7 via a key connection to ensure stable power transmission. One end of the cable 9 is wound around the cable reel 7, and the other end is used to connect to the seabed anchoring device. The electric winch 8 drives the cable reel 7 to rotate, which enables the cable 9 to be wound or released. The buoyancy control system automatically adjusts the buoy's draft based on power supply data, monitoring data, and ocean current parameters collected by sensors, enabling intelligent switching between "working state" and "charging state": In working state, to meet specific monitoring task requirements, the buoyancy control system adjusts the cable length to maintain the buoy at a preset working depth, ensuring the monitoring range meets task requirements; in charging state, if the stored energy in the power supply data is determined to be lower than a preset stored energy value (e.g., 70%), the system collects the incoming current velocity through the current velocity sensor 5 (…). ), combined with the natural frequency of the cylindrical oscillator ( ) and diameter ( ), by reducing the velocity formula

[0040] Calculate the current reduced velocity, and combine it with the water flow disturbance intensity collected by turbulence sensor 6. ), through the optimal depth decision formula

[0041] In the formula: , Let be the weighting coefficient, satisfying , The optimal depth function corresponding to the reduced velocity. The correction function corresponding to the disturbance intensity is used to calculate the optimal draft. The buoy is positioned at this optimal depth by adjusting the cable retraction and extension of the buoy through the buoy control system. This ensures that the vortex-induced vibration efficiency is within the optimal range and the water flow disturbance is minimized, thereby maximizing the energy capture efficiency. If the monitoring range in the monitoring data is determined to be less than the preset monitoring range, the draft is increased through the buoy control system to allow the transceiver device to increase the monitoring range.

[0042] The working method of the self-powered buoy based on fluid kinetic energy capture by flow-induced vibration is as follows: First, the antenna 1 on the top of the outer shell 2 transmits and receives power supply data, monitoring data, and ocean current parameters collected by sensors in real time, providing data basis for the operation and control of the buoy; Second, the cylindrical oscillator 4 in the multi-oscillator flow-induced vibration piezoelectric energy capture system captures the mechanical energy of the ocean current in its entire circumference. When the ocean current flows through the buoy, at least one cylindrical oscillator 4 vibrates under the action of alternating shedding of vortices. This vibration is transmitted to the piezoelectric element 3 through the angle steel 10, causing the piezoelectric element 3 to bend and deform. The piezoelectric element 3 uses the positive piezoelectric effect to convert the captured mechanical energy into electrical energy; The generated electrical energy is transmitted to the rectification control circuit inside the outer shell 2. After rectification and control, a portion of the electrical energy is directly supplied to the transceiver signal device, the buoyancy control system, the current velocity sensor 5, and the turbulence sensor 6. In use, another portion of the electrical energy is transferred to the battery for storage; finally, the buoyancy control system automatically adjusts the buoy's draft based on the power supply data, monitoring data, and ocean current parameters obtained by the transceiver device, realizing intelligent switching between working and charging states.

[0043] This buoy includes a buoy body, a multi-oscillator flow-induced piezoelectric energy harvesting system, a buoyancy control system, and a sensor monitoring system; Buoy body: The outer shell 2 is made of waterproof material (such as engineering plastic or stainless steel), and the battery and rectifier control circuit are sealed inside; the antenna 1 is fixed to the top of the outer shell 2 through a waterproof connector, and has data transmission and reception and remote control functions.

[0044] Multi-oscillator flow-induced vibration piezoelectric energy harvesting system: Three cylindrical oscillators 4 are evenly distributed at 120° intervals along the circumference of the outer shell 2; the angle steel 10 is made of metal, and each set of cylindrical oscillators 4 corresponds to a set of angle steel 10. The two branches of the angle steel 10 are fastened to the outside of the outer shell 2 and the end of the cylindrical oscillator 4 respectively by screws 11; the piezoelectric sheet 3 is made of piezoelectric ceramic or piezoelectric polymer, and the surface is coated with a waterproof resin (such as epoxy resin) of uniform thickness. It is tightly attached to the connection area of ​​each set of "angle steel 10 and outer shell 2" and "angle steel 10 and cylindrical oscillator 4" to ensure effective bending strain during vibration transmission.

[0045] Sensor monitoring system: Three flow velocity sensors 5 and three turbulence intensity sensors 6 are evenly arranged around the circumference of the outer shell 2, and are set directly opposite the cylindrical vibrator 4; the flow velocity sensors 5 are waterproof electromagnetic flow velocity sensors; the turbulence intensity sensors 6 are ultrasonic turbulence intensity sensors; both are connected to the internal circuit of the outer shell 2 through waterproof cables to realize real-time data acquisition and transmission.

[0046] Buoyancy control system: The electric winch 8 is a miniature waterproof type and is fixed inside the outer shell 2; the cable shaft 7 is keyed to the output shaft of the electric winch 8, one end of the cable 9 is wound around the cable shaft 7, and the other end is used to connect to the seabed anchoring device; the electric winch 8 is powered and controlled by the circuit inside the outer shell 2 to realize the winding or unwinding of the cable 9.

[0047] like Figure 3 As shown in (A) and (B), when the ocean current flows through the cylindrical oscillator 4 structure, the fluid forms a flow around the surface of the structure, generating alternating detached Karman vortex streets behind the structure. This periodic vortex shedding generates periodic lateral lift and axial drag on the cylindrical oscillator 4, driving it to perform simple harmonic vibrations perpendicular to the ocean current. This vibration is transmitted to the piezoelectric element 3 through the mechanical structure. The piezoelectric element 3 utilizes the positive piezoelectric effect to convert the strain generated by the mechanical vibration into electrical energy, thereby achieving a stable conversion of ocean current kinetic energy into electrical energy. The core advantage of this principle is that it can be started at low flow rates, does not require a specific working plane, and is not limited by changes in ocean current direction and wave height, making it perfectly suited to the marine working environment of buoys.

[0048] As shown in Figure 4, when the ocean current flows past the buoy from any direction, thanks to the omnidirectional arrangement of the three cylindrical oscillators 4 along the circumference of the shell, at least one cylindrical oscillator 4 can be in the optimal flow around the buoy without flow field obstruction. At the same time, the corresponding flow velocity sensor 5 and turbulence intensity sensor 6 can accurately collect the incoming flow velocity and disturbance intensity data in this area, ensuring the continuity, efficiency and accuracy of omnidirectional energy capture and parameter monitoring.

[0049] As shown in Figure 5, specifically in Figure 5(A), in the working state, the electric winch 8 drives the cable shaft 7 to wind or release the cable 9, and the buoy remains at the preset working depth to ensure that the monitoring range meets the task requirements; specifically in Figure 5(B), in the charging state, based on the incoming flow velocity collected by the flow velocity sensor 5 (… ), combined with the natural frequency of the cylindrical oscillator ( ) and diameter ( ), through formula

[0050] The reduced velocity was calculated, and the disturbance intensity was also collected by the turbulence sensor 6. Substitute into the optimal depth decision formula

[0051] Calculate the optimal depth, and the electric winch 8 drives the cable shaft 7 to adjust the length of the cable 9 so that the buoy is at the optimal depth. This ensures that the vortex-induced vibration efficiency is in the optimal range, reduces the impact of water flow disturbance, and maximizes the energy capture efficiency.

[0052] It should be noted that: This working method achieves closed-loop optimization of the floating and sinking state through formula calculations of "precise calculation of reduced velocity - turbulence correction - optimal depth decision", ensuring that the cylindrical oscillator is both in the optimal range of vortex-induced vibration efficiency and avoids the influence of highly disturbed water flow. The specific formulas and logic are as follows: Reduction speed ( As a core dimensionless parameter characterizing the coupling relationship between the incoming flow velocity and the inherent characteristics of the cylindrical oscillator, it directly determines whether the oscillator enters the "synchronization (frequency locking) range" for efficient energy capture—when Within a specific range (e.g.) When the vortex shedding frequency matches the natural vibration frequency of the oscillator, the vortex-induced vibration intensity is maximized, corresponding to the highest energy capture efficiency. This invention uses a flow velocity sensor to obtain the inflow velocity in real time. Based on the inherent parameters of the oscillator structure, the reduced velocity is calculated using the following formula:

[0053] In the formula: For depth The actual incoming flow velocity (unit: m / s) at the location is collected in real time by flow velocity sensors that are arranged one-to-one with the cylindrical oscillator to ensure the consistency of the data with the force environment of the oscillator; Hz is the natural frequency of the cylindrical oscillator. It is an inherent property of the oscillator structure and is determined by the oscillator mass and the stiffness of the elastic support. It is calibrated experimentally before leaving the factory (calibration method: obtain the vibration period through a free decay test and calculate the frequency value). is the diameter of the cylindrical oscillator (unit: m), is a core design parameter of the buoy, which directly affects the vortex shedding frequency, and is a fixed value.

[0054] To simultaneously achieve the dual objectives of "high vortex-induced vibration efficiency" and "low water flow disturbance," this invention introduces a turbulence intensity sensor to monitor the intensity of water flow disturbance. Using this as a correction parameter, a weighted optimization formula for the optimal depth decision is constructed, as follows:

[0055] In the formula: The optimal draft of the buoy (in meters) is the final deployment depth of the cylindrical oscillator. 、 Let be the weighting coefficient, satisfying ,in Reduce the dominant weight for speed (range of values) ), Turbulence intensity correction weights (range of values) The adjustment can be made dynamically according to the actual sea conditions (e.g., increasing the area of ​​strong disturbance). ); The core logic of the baseline optimal depth function corresponding to the reduced velocity is as follows: based on previous flume experiment data, establish... Mapping relationship with "optimal depth" - when Falling within the preset high-efficiency range (e.g.) )hour, Output the corresponding depth value; if Below the lower limit of the range, Output a shallower depth value (to increase incoming flow speed); if Higher than the upper limit of the range, Output a deeper depth value (reduce the incoming flow rate); The depth correction function corresponding to turbulence intensity has the following core logic: (dimensionless, value) The larger the value, the stronger the water flow disturbance. It outputs a correction value deeper than the reference depth, avoiding highly disturbed surface water flow by sinking; The smaller, Output a correction value that is consistent with or slightly shallower than the reference depth to ensure energy capture efficiency; The intensity of water flow disturbance (dimensionless) is collected in real time by a turbulence intensity sensor. Its value is calculated by the percentage deviation between the instantaneous flow velocity and the average flow velocity, and directly reflects the stability of the water flow.

[0056] Through the calculations using the above formula, the system can automatically adapt to different ocean current conditions: when the incoming current velocity is low, based on... Adjust the calculation results to a shallower depth. Upgrade to the high-efficiency range; when surface water flow disturbance is strong, combine with The correction results are adjusted to a deeper, low-perturbation region, while ensuring the weighting coefficients are allocated to ensure... It remains close to the high-efficiency range. This design overcomes the energy harvesting efficiency fluctuations caused by the fixed depth of traditional buoys, and solves the problem of ignoring the impact of water flow disturbance by relying solely on flow velocity regulation. It significantly improves the system's energy supply stability and monitoring reliability under complex sea conditions, and reduces manual maintenance costs.

[0057] In summary, the self-powered buoy and its operating method based on fluid kinetic energy capture by flow-induced vibration provided by this invention have the following advantages compared with existing buoys: First, the power supply system and the buoyancy system are deeply integrated: relying on the principle of flow-induced vibration to obtain ocean current energy, combined with the accurate monitoring data of current velocity sensor and turbulence sensor, the buoyancy state is intelligently controlled through formula calculation, forming a "monitoring-calculation-control-energy capture" control system. This achieves deep integration of power supply and buoyancy from the design level, avoiding the defects of traditional buoys where the two are disconnected. Second, it has strong adaptability to working conditions: through intelligent switching between "working state" and "charging state", it can not only meet the depth requirements of different monitoring tasks, but also dynamically match the optimal energy capture depth according to ocean current parameters, and can work efficiently in complex scenarios such as high / low ocean current, shallow / deep sea state, and strong / weak disturbance. Third, it has good self-powered sustainability: the core relies on the inherent advantages of flow-induced vibration technology - ocean currents are a continuous fluid dynamic in the ocean. As long as there is a low flow velocity of ≥0.01m / s (far lower than the starting flow velocity of more than 1m / s for turbine buoys), the ocean current will generate a vortex alternating shedding effect when it flows through the cylindrical oscillator 4, driving the oscillator to vibrate and driving the piezoelectric sheet 3 to continuously generate electricity; with the multi-oscillator full-circumferential layout, no matter how the direction of the ocean current changes, there is always an oscillator in an effective energy-capturing state. Combined with the stable power conversion of the rectifier control circuit and battery energy storage, a continuous cycle of "energy capture-energy storage-energy supply" can be achieved, without relying on external power supply or regular battery replacement, greatly reducing the dependence on manual maintenance and ensuring the long-term autonomous operation of the buoy; Fourth, it combines omnidirectional energy capture with precise monitoring: three cylindrical oscillators are evenly distributed around the circumference of the shell to ensure omnidirectional ocean current energy capture, and the corresponding sensors simultaneously monitor omnidirectional ocean current parameters, which greatly improves the completeness of omnidirectional energy acquisition and the accuracy of working condition adaptation, solving the problem of poor directional adaptability of traditional schemes with few oscillators and no precise monitoring.

[0058] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A self-powered buoy based on fluid kinetic energy capture using flow-induced vibration, characterized in that, Including the outer casing (2); The top of the outer shell (2) is provided with a signal transceiver device, which is used to transmit and receive power supply data, monitoring data and ocean current parameters; the ocean current parameters include the incoming current velocity and the intensity of water flow disturbance. The top of the outer shell (2) is provided with a multi-oscillator flow-induced vibration piezoelectric energy harvesting system and a buoyancy control system; the multi-oscillator flow-induced vibration piezoelectric energy harvesting system is connected to the transceiver signal device and the buoyancy control system respectively; An energy storage device is provided inside the outer shell (2); the energy storage device is connected to the multi-oscillator flow-induced piezoelectric energy harvesting system, the transceiver signal device and the buoyancy control system respectively; The multi-oscillator flow-induced vibration piezoelectric energy harvesting system includes at least 3 sets of energy harvesting components; each set of energy harvesting components is evenly arranged along the bottom circumferential direction of the shell (2); The energy-harvesting component includes a piezoelectric sheet (3) connected to the outer shell (2); the piezoelectric sheet (3) is connected to a cylindrical oscillator (4); each cylindrical oscillator (4) can capture the mechanical energy of the ocean current in the full circumference so that the piezoelectric sheet (3) deforms and converts the mechanical energy into electrical energy; Multiple flow velocity sensors (5) and multiple turbulence intensity sensors (6) are provided on the outer side of the outer shell (2). Each flow velocity sensor (5) and each turbulence intensity sensor (6) corresponds to each set of energy harvesting components. They are evenly arranged along the circumference of the outer shell (2) and are directly opposite to the cylindrical oscillator (4). The flow velocity sensor (5) is used to monitor the incoming flow velocity in real time, and the turbulence intensity sensor (6) is used to monitor the water flow disturbance intensity in real time. Both are electrically connected to the signal receiving and transmitting device and the buoyancy control system. The buoyancy control system is used to automatically adjust the draft of the buoy based on power supply data, monitoring data and ocean current parameters collected by sensors, so as to realize intelligent switching between working state and charging state, so as to allow the multi-oscillator flow-induced vibration piezoelectric energy harvesting system to adjust the flow-induced vibration intensity, or / and to allow the transceiver device to adjust the monitoring range. In the charging state: if the energy stored in the energy supply data is lower than the preset energy storage value, the incoming flow velocity is obtained by the flow velocity sensor (5), and the reduced velocity is calculated by combining the natural frequency and diameter of the cylindrical oscillator. At the same time, the water flow disturbance intensity is obtained by the turbulence intensity sensor (6), and the optimal draft is calculated by the optimal depth decision formula. The buoyancy control system adjusts the cable release and release to make the buoy at the optimal depth to increase the intensity of flow-induced vibration.

2. The self-powered buoy based on fluid kinetic energy capture using flow-induced vibration as described in claim 1, characterized in that, The shell (2) is also equipped with a rectification control circuit; the rectification control circuit is connected to the energy storage device, the signal receiving and transmitting device, the buoyancy control system, the flow velocity sensor (5) and the turbulence sensor (6) respectively, and is used to rectify and control the electrical energy passing through the shell (2), and transmit the rectified electrical energy to the energy storage device, the signal receiving and transmitting device, the buoyancy control system, the flow velocity sensor (5) and the turbulence sensor (6).

3. A self-powered buoy based on fluid kinetic energy capture using flow-induced vibration as described in claim 1, characterized in that, The outer shell (2) is made of waterproof material; the transceiver device is an antenna (1); the antenna (1) is connected to the top of the outer shell (2) through a waterproof connector.

4. A self-powered buoy based on fluid kinetic energy capture using flow-induced vibration as described in claim 1, characterized in that, The piezoelectric element (3) is connected to the outer shell (2) and the cylindrical vibrator (4) respectively via angle steel (10); the angle steel (10) is made of metal.

5. A self-powered buoy based on fluid kinetic energy capture using flow-induced vibration as described in claim 1, characterized in that, The piezoelectric sheet (3) is made of piezoelectric ceramic or piezoelectric polymer material and has a resin coating on its surface; each piezoelectric sheet (3) is tightly attached to the connection area between the angle steel (10) and the outer shell (2) and the connection area between the angle steel (10) and the cylindrical vibrator (4).

6. A self-powered buoy based on fluid kinetic energy capture using flow-induced vibration as described in claim 1, characterized in that, The buoyancy control system includes an electric winch (8), a cable shaft (7), and a cable (9). The electric cable winch (8) is fixed on the outer casing (2), and its output end is connected to the cable shaft (7) by a key connection. One end of the cable (9) is wrapped around the cable shaft (7), and the other end is used to connect to the seabed anchoring device; The electric cable winch (8) is connected to the multi-vibrator flow-induced piezoelectric energy harvesting system and the energy storage device, respectively.

7. A self-powered buoy based on fluid kinetic energy capture using flow-induced vibration as described in claim 6, characterized in that, The body of the electric cable winch (8) is located inside the outer casing (2).

8. A self-powered buoy based on fluid kinetic energy capture using flow-induced vibration as described in claim 6, characterized in that, Each of the energy-harvesting components is vertically connected to the bottom of the outer casing (2).

9. A method for operating a self-powered buoy based on fluid kinetic energy capture using flow-induced vibration, based on the self-powered buoy based on fluid kinetic energy capture using flow-induced vibration as described in any one of claims 1-8, characterized in that, include: The transceiver device transmits and receives power supply data, monitoring data, and ocean current parameters collected by sensors; The cylindrical oscillator (4) captures the mechanical energy of the ocean current in the whole circumference, causing the piezoelectric sheet (3) to deform and convert the mechanical energy into electrical energy; The buoyancy control system automatically adjusts the draft of the buoy based on the power supply data, monitoring data, the incoming flow velocity collected by the flow velocity sensor (5) and the water flow disturbance intensity obtained by the turbulence intensity sensor (6), so as to realize the intelligent switching between working state and charging state, so as to allow the multi-oscillator flow-induced vibration piezoelectric energy harvesting system to adjust the flow-induced vibration intensity, or / and to allow the transceiver signal device to adjust the monitoring range.

10. The operating method of a self-powered buoy based on fluid kinetic energy capture using flow-induced vibration according to claim 9, characterized in that, The automatic adjustment of the buoy's draft by the buoyancy control system based on power supply data, monitoring data, and ocean current parameters collected by sensors includes: Working status: According to the monitoring task requirements, the length of the cable is adjusted through the buoyancy control system to keep the buoy at the preset working depth; Charging status: If the energy storage in the power supply data is lower than the preset energy storage value, the incoming flow velocity is obtained through the flow velocity sensor (5), and the reduced velocity is calculated by combining the natural frequency and diameter of the cylindrical oscillator. At the same time, the water flow disturbance intensity is obtained by the turbulence intensity sensor (6), and the optimal draft is calculated by the optimal depth decision formula. The buoyancy control system adjusts the cable release and retraction to make the buoy at the optimal depth to increase the intensity of flow-induced vibration. The specific calculation formula for the reduced velocity is as follows: In the formula, To reduce the speed; For depth The actual incoming flow velocity at the location; is the natural frequency of the cylindrical oscillator; D is the diameter of the cylindrical oscillator; The specific formula for calculating the optimal draft is as follows: In the formula, The optimal draft for the buoy; 、 For different weighting coefficients; The baseline optimal depth function corresponding to the reduced velocity; This is the depth correction function corresponding to the turbulence intensity; If the monitoring range in the monitoring data is determined to be less than the preset monitoring range, the draft is increased through the buoyancy control system so that the signal receiving and transmitting device can increase the monitoring range.

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