A gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device

Abstract

This invention discloses a gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device, belonging to the field of marine wave energy power generation devices. It includes a floating shell, a gradient frustum array skeleton unit, orthogonally arranged vibration energy harvesters, and a power management module. Through key technologies such as gradient frustum wideband adaptation, orthogonal energy harvesting array omnidirectional capture, magnetic coupling displacement amplification and limiting, and d33 mode piezoelectric conversion, it simultaneously captures multi-directional wave energy, adapts to 0.5-5Hz wideband waves, amplifies piezoelectric deformation, and achieves overload protection. It solves the problems of narrow energy harvesting bandwidth, low conversion efficiency, and weak environmental adaptability of existing devices, achieving efficient wave energy harvesting and in-situ power supply, and improving the device's service life and adaptability to the marine environment.

Description

Technical Field

[0001] This invention relates to the field of marine renewable energy utilization and distributed self-powered technology, specifically to an omnidirectional broadband piezoelectric wave energy capture device suitable for nearshore multi-directional irregular wave environments. Background Technology

[0002] While there is considerable research on wave energy generation devices that utilize ocean wave energy through pressure power generation, most of these devices employ a single-length piezoelectric structure. This structure is susceptible to the variability of wave frequencies, leading to a mismatch with the optimal operating frequency of the piezoelectric material, making resonance matching difficult. Consequently, they cannot adapt to the complex, wide-band wave environment of the ocean, resulting in intermittent power generation and unstable energy output. Furthermore, most devices employ a single method of wave energy capture, resulting in significant energy loss. Some devices also have complex structures, large volumes, and are prone to fatigue failure under harsh sea conditions, limiting their service life.

[0003] The existing Chinese patent with publication number CN118481896A, published on August 13, 2024, proposes a combination structure of push-pull rod and cantilever beam. Although it is sensitive to wave energy, converts irregular energy, and improves the energy absorption rate, it does not solve the problem of coordinated utilization of energy in multiple directions of motion, resulting in a single energy utilization and failing to solve the problem of broadband resonance. The Chinese patent with publication number CN222650089U, published on March 21, 2025, uses magnetic repulsion to drive the deformation of piezoelectric sheets and the rotation of rollers to obtain energy. Its structure is simple and conducive to miniaturization, but it can only capture rotational energy in a single direction, resulting in insufficient energy utilization.

[0004] Therefore, there is an urgent need for an omnidirectional broadband piezoelectric power generation device that can adapt to the complex wave environment of nearshore areas to solve the problems of narrow energy capture bandwidth, multi-directional energy loss, low conversion efficiency, weak sea condition adaptability, and easy damage to the device. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides a gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device. Through a composite scheme of modular cube multi-frequency multi-degree-of-freedom design and magnetic coupling displacement amplification and limiting mechanism, it achieves broadband wave capture, multi-directional energy conversion and zero external loss self-driven operation, providing a new path for the efficient utilization of wave energy.

[0006] This invention is achieved through the following technical solutions: A gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device includes a coaxially sealed floating shell, an internal gradient frustum array skeleton unit, multiple sets of orthogonally arranged vibration energy harvesters, and a matching power management module. The gradient frustum array skeleton unit is a three-layer coaxially arranged frustum structure, with the diameter and stiffness of the frustums increasing gradually from top to bottom. A cubic support base is set at the center of each frustum layer, and the base is rigidly connected to the inner wall of the corresponding frustum through four radial support rods. On each of the six faces of each cubic support base, one set of vibration energy harvesters is vertically installed along the three orthogonal axes of X, Y, and Z, forming three pairs of completely symmetrical and spatially decoupled omnidirectional energy harvesting arrays. The outer end of each vibration energy harvester is rigidly connected to the inner wall of the floating shell, and the internal components integrate a magnetically coupled displacement amplification and limiting mechanism and a flexible compression transducer. The power management module is electrically connected to all the flexible compression transducers for rectification, voltage stabilization, and energy storage.

[0007] Furthermore, the floating outer shell is buoy-shaped. The depth of the float in the water directly affects the absorption of waves by the vibration energy harvesting structure. With this shell shape that is larger at the top and smaller at the bottom, the depth of the float in the water is appropriate, and the float can more easily transmit wave vibrations, so that the operating frequency of the energy harvesting device matches the variable movement frequency of the buoy in the marine environment.

[0008] Furthermore, the gradient frustum array skeleton unit is a three-layer coaxial vertically arranged hollow frustum structure. The central axis of the three frustums coincides with the central axis of the floating shell. From top to bottom, they are an upper high-frequency response frustum, a middle mid-frequency response frustum, and a lower low-frequency response frustum. The base diameter of the frustums increases sequentially from top to bottom in a ratio of 1:1.5:2. The cone angle of the frustums is 30°-60°, and the interlayer spacing is 1 / 3-1 / 2 of the total height of the frustums. The wall thickness of the frustums increases sequentially from top to bottom. The material's elastic modulus increases, and the natural frequencies of the corresponding frustums decrease sequentially. The vibration energy harvester of the upper frustum covers a natural frequency range of 3-5Hz, the middle layer covers 1-3Hz, and the lower layer covers 0.5-1Hz. The three-layer array works together to achieve full-band coverage of 0.5-5Hz, accurately adapting to the wave frequency range of my country's nearshore waters. The vibration energy harvesters of the three frustums are arranged in a 60° staggered arrangement in the circumferential direction to avoid vibration coupling interference between different layers and ensure that each layer responds independently to wave excitation at the corresponding frequency.

[0009] Furthermore, the cubic support base is located at the geometric center of the corresponding frustum, and four radial support rods are evenly distributed along the circumference of the frustum. The two ends are welded and fixed to the side wall of the base and the inner wall of the frustum, respectively, so as to realize the rigid synchronous movement of the base, the frustum and the floating shell without transmission loss.

[0010] Furthermore, each of the six faces of the cubic support base corresponds to the six directions of the spatial rectangular coordinate system: X+, X-, Y+, Y-, Z+, and Z-. A set of vibration energy harvesters is vertically installed at the center of each face, forming three pairs of completely symmetrical orthogonal energy-harvesting arrays. The two sets of harvesters along the X-axis respond only to horizontal transverse wave excitation in the X direction, the two sets of harvesters along the Y-axis respond only to horizontal longitudinal wave excitation in the Y direction, and the two sets of harvesters along the Z-axis respond only to vertical wave excitation in the Z direction. The vibrations of the three axis harvesters are completely independent and do not interfere with each other, achieving synchronous capture of 6-DOF omnidirectional wave energy. To address the differences in excitation characteristics between horizontal and vertical waves, the harvesters along different axes employ differentiated parameter designs. The Z-axis cantilever beam is longer and the magnetic mass is heavier, adapting to low-frequency vertical waves of 0.5-2Hz. The X-axis and Y-axis cantilever beams are shorter and have higher stiffness, adapting to high-frequency transverse waves of 2-5Hz, further broadening the frequency response range of the device.

[0011] Furthermore, the vibration energy harvester consists of a rectangular fixed frame, a cantilever beam, a magnetic mass block, two sets of fixed magnets, and two sets of flexible compression transducers. The outer side of the rectangular fixed frame is rigidly connected to the inner wall of the floating shell, and the inner side is rigidly connected to the corresponding surface of the cubic support base. The root of the cantilever beam is rigidly fixed to the middle of the inner side of the rectangular fixed frame, with the free end facing the center of the rectangular fixed frame. The magnetic mass block is fixed to the free end of the cantilever beam. The two sets of fixed magnets are respectively fixed at the upper and lower corners of one side of the rectangular fixed frame, arranged opposite to the magnetic mass block with the same pole, forming a nonlinear magnetic repulsion mechanism. The two sets of flexible compression transducers are respectively fixed at the two corners of the other side of the rectangular fixed frame, symmetrically arranged on both sides of the cantilever beam, and the driving end of the flexible compression transducer abuts against the side of the cantilever beam.

[0012] The flexible compression transducer consists of a clamping frame and a multilayer piezoelectric ceramic stack. The multilayer piezoelectric ceramic stack is arranged along the axial direction of the flexible compression transducer. The clamping frame includes a rhomboid shell and fastening screws for fixing the piezoelectric ceramic stack and applying preload. When the cantilever beam vibrates, the thrust on its side acts on the rhomboid shell, and the deformation of the clamping frame pushes the multilayer piezoelectric ceramic stack to produce axial compression deformation. The multilayer piezoelectric ceramic stack adopts the d33 piezoelectric working mode, which improves the piezoelectric conversion efficiency by more than 3 times compared with the d31 mode of the traditional cantilever beam bending, solving the pain points of small piezoelectric deformation and conversion efficiency of less than 15% in the existing technology. The flexible compression transducer is externally equipped with an IP68 waterproof and corrosion-resistant encapsulation layer, which is covered with polytetrafluoroethylene material, making it suitable for underwater working environments with high salt spray and high humidity in the ocean, and improving the service life of the device.

[0013] Furthermore, the vibration energy harvester adopts an integrated design of magnetic coupling displacement amplification and limiting, so that the magnetic mass block and the same pole of the fixed magnet are opposite each other, introducing nonlinear magnetic repulsion force, which amplifies the small bending displacement of the cantilever beam by 5-10 times, greatly increasing the deformation of the piezoelectric ceramic, and making the natural frequency of the cantilever beam distributed in a range, thus widening the frequency band coverage of a single harvester by more than 3 times. When the wave impact is too large and the displacement of the cantilever beam exceeds the safety threshold, the magnetic repulsion force grows nonlinearly exponentially, forming a non-contact hard limit, completely avoiding mechanical collisions between the cantilever beam and other components, while limiting the maximum compression of the piezoelectric ceramic and preventing structural fatigue damage.

[0014] Furthermore, the power management module uses a battery to store energy, and its circuit consists of a rectifier bridge and a supercapacitor; the battery regulates the charging frequency; the size of the capacitor is selected according to the magnitude of the generated current, and it plays a role in voltage stabilization; after the supercapacitor is fully charged, it discharges and then stores the energy in the battery.

[0015] As a further technical solution, the working process of the gradient frustum array multi-degree-of-freedom omnidirectional piezoelectric power generation device is as follows: The power generation device floats on the near-shore sea surface through a floating shell, and performs translational and rotational movements in the X / Y / Z directions with irregular waves. The shell drives the internal gradient frustum array skeleton units to perform synchronous rigid movements. Due to the inertia of the magnetic mass block at the free end of the cantilever beam, the cantilever beam in the X-axis responds to the horizontal transverse wave excitation and bends, the cantilever beam in the Y-axis responds to the horizontal longitudinal wave excitation and bends, and the cantilever beam in the Z-axis responds to the vertical wave excitation and bends, realizing the synchronous capture of wave energy in all directions and multiple degrees of freedom without multi-directional energy loss; wave excitation of different frequencies excites the cantilever beams of the corresponding gradient layers. Resonance generation: High-frequency waves excite the short cantilever beam resonance of the upper cone, mid-frequency waves excite the mid-layer resonance, and low-frequency waves excite the long cantilever beam resonance of the lower layer, achieving a wide-band response of 0.5-5Hz and solving the problems of detuning and power generation interruption in traditional devices; When the cantilever beam bends and vibrates, the driving force is amplified by nonlinear magnetic repulsion, which pushes the clamping frame of the flexible compression transducer, causing the piezoelectric ceramic stack to produce periodic axial compression deformation; Based on the positive piezoelectric effect, the two pole surfaces of the piezoelectric ceramic stack generate periodically changing charges, which are transmitted to the power management module through wires. After rectification and voltage stabilization, the charges are stored in the supercapacitor or directly drive marine monitoring sensors and intelligent devices, realizing the efficient conversion and in-situ utilization of wave energy to electrical energy.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention achieves full-band coverage of 0.5–5Hz by using a three-layer gradient frustum array skeleton unit in conjunction with axially differentiated cantilever beam parameter design, accurately matching the wave frequency range of my country's nearshore waters, and fundamentally solving the problem of narrow resonant frequency band of traditional devices.

[0017] (2) The present invention amplifies the minute displacement of the cantilever beam through a magnetic coupling displacement amplification limiting mechanism, while achieving non-contact limiting, avoiding mechanical wear and improving the life of the device.

[0018] (3) The present invention adopts a cubic support base and a vibration energy harvester arranged orthogonally in the X / Y / Z directions, which can synchronously respond to wave excitation in the X / Y / Z directions, solve the problem of multi-directional wave energy loss, and greatly improve the wave energy capture efficiency.

[0019] (4) The flexible compression transducer of the present invention adopts the d33 piezoelectric working mode. Compared with the traditional cantilever beam bending d31 mode, the piezoelectric conversion efficiency is increased by more than 3 times, solving the pain points of small piezoelectric deformation and insufficient conversion efficiency in the existing technology.

[0020] (5) The present invention adopts a modular sealing design, and the floating shell and the gradient cone frame move synchronously with no transmission loss; the flexible compression transducer adopts IP68 waterproof and corrosion resistant encapsulation, which is suitable for harsh marine environments with high salt spray and high humidity; the overall structure is compact and small in size, which is convenient to integrate with marine monitoring buoys and marine ranch intelligent equipment to achieve in-situ self-powered power supply.

[0021] (6) This invention does not require complex transmission and external drive. It achieves self-driven operation by relying on wave excitation, with fewer energy conversion links and lower losses. The matching power management module completes rectification, voltage stabilization and energy storage, and outputs stable power, which can directly provide continuous power to marine distributed equipment and meet the needs of long-term unattended operation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device according to an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the structure of a floating hull according to an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of a vibration energy harvester according to an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the layout of a vibration energy harvester according to an embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of a flexible compression transducer according to an embodiment of the present invention.

[0027] Figure 6 This is a circuit diagram of a power management module according to an embodiment of the present invention.

[0028] In the figure: 1. Floating shell; 2. Cube support base; 3. Support rod; 4. Vibration energy harvester; 5. Rectangular fixed frame; 6. Flexible compression transducer; 7. Cantilever beam; 8. Magnetic mass block; 9. Fixed magnet; 10. Rhomboid shell; 11. Fastening screw; 12. Piezoelectric ceramic stacked sheet. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] To better understand this invention, the following is combined with... Figures 1-6 The working principle of the technical solution of the present invention will be described in detail below. The device includes a coaxial sealed floating shell 1, an internal gradient frustum array skeleton unit, multiple sets of orthogonally arranged vibration energy harvesters 4, and a power management module; the floating shell 1 is a buoy-shaped sealed structure adapted to wave vibration transmission, and its inner wall is rigidly connected to the gradient frustum array skeleton unit and the vibration energy harvesters 4; the gradient frustum array skeleton unit is a three-layer coaxial vertical hollow frustum structure, from top to bottom, consisting of an upper high-frequency, a middle mid-frequency, and a lower low-frequency response frustum, with increasing diameter, wall thickness, and material elastic modulus, and decreasing natural frequency gradient. Each frustum has a cubic support base 2 at its geometric center, which is rigidly welded to the inner wall of the frustum by four radial support rods 3; each of the six faces of each cubic support base 2 is vertically mounted with one set of vibration energy harvesters 4, forming three pairs of orthogonal energy harvesting arrays. The vibration energy harvesters 4 of the three frustums are arranged in a 60° staggered arrangement around their circumference to avoid vibration coupling interference. The vibration energy harvester 4 consists of a rectangular fixed frame 5, a cantilever beam 7, a magnetic mass block 8, two sets of fixed magnets 9, and two sets of flexible compression transducers 6. The outer side of the rectangular fixed frame 5 is connected to the inner wall of the floating shell 1, and the inner side is connected to the cubic support base 2. The root of the cantilever beam 7 is fixed to the inner side of the rectangular fixed frame 5, and the free end is provided with a magnetic mass block 8. The two sets of fixed magnets 9 and the magnetic mass block 8 are opposite each other with the same pole, forming a nonlinear magnetic repulsion mechanism. The two sets of flexible compression transducers 6 are symmetrically arranged on both sides of the cantilever beam 7, and the driving end abuts against the side of the cantilever beam 7.

[0031] The flexible compression transducer 6 consists of a clamping frame and a multilayer piezoelectric ceramic stack 12 The system consists of a clamping frame containing a rhomboid outer shell 10 and fastening screws 11. Piezoelectric ceramic stacked sheets 12 are arranged axially and pre-tightened, employing a d33 piezoelectric working mode. The exterior is encapsulated with an IP68-level waterproof and corrosion-resistant polytetrafluoroethylene layer. The power management module consists of a rectifier bridge, a supercapacitor, and a storage battery, and is electrically connected to all flexible compression transducers 6 for power rectification, voltage regulation, storage, and output. The floating outer shell 1 moves and rotates in the X / Y / Z directions with irregular waves, synchronously driving the rigid movement of the internal gradient frustum array skeleton unit. Due to the inertia of the magnetic mass block 8, the cantilever beam 7 bends in the X, Y, and Z directions respectively, achieving 6-DOF omnidirectional wave energy capture. Wave excitation at the same frequency stimulates the corresponding gradient layer cantilever beam 7 to resonate, with the upper frustum responding to 3-5Hz high frequency, the middle layer to 1-3Hz mid frequency, and the lower layer to 0.5-1Hz low frequency, achieving a 0.5-5Hz wideband response.

[0032] When the cantilever beam 7 bends, the nonlinear magnetic repulsion amplifies the minute displacement, causing the rhomboid shell 10 of the flexible compression transducer 6 to deform, resulting in axial compression deformation of the piezoelectric ceramic stack 12. Based on the positive piezoelectric effect, the mechanical energy is converted into electrical energy. The alternating charge generated by the piezoelectric ceramic is rectified and the voltage is stabilized by the power management module. Part of it directly powers the marine in-situ equipment, and the other part is stored in the energy storage battery. When the environment is harsh, if the displacement of the cantilever beam 7 is too large and exceeds the safety threshold, the magnetic repulsion will increase exponentially, forming a hard limit to avoid mechanical collision and damage to the piezoelectric ceramic.

[0033] The gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device provided by the present invention has the following beneficial effects: (1) The present invention adopts a cubic support base in conjunction with a vibration energy harvester arranged orthogonally in the X / Y / Z directions to achieve 6-degree-of-freedom omnidirectional wave energy capture, solving the problem of large-scale energy loss in multiple directions in traditional devices, and significantly improving energy utilization.

[0034] (2) The three-layer gradient cone of the present invention forms a segmented response structure of high frequency, medium frequency and low frequency from top to bottom. Combined with the axially differentiated cantilever beam parameters, it fully covers the near-shore wave frequency of 0.5–5Hz. Waves of different frequencies can excite the corresponding level resonance, avoiding detuning, power generation interruption and power fluctuation.

[0035] (3) The flexible compression transducer of the present invention adopts the axial compression d33 working mode, which improves the conversion efficiency by more than 3 times compared with the traditional bending d31 mode, thereby improving the piezoelectric energy capture efficiency.

[0036] (4) The present invention amplifies the small displacement of the cantilever beam by 5–10 times through the integrated design of magnetic coupling displacement amplification and limiting, which greatly improves the piezoelectric deformation; at the same time, it forms a non-contact hard limit to avoid collision, fatigue fracture and overload damage of the cantilever beam and piezoelectric ceramic. It has no mechanical wear, high reliability and significantly extends the service life of the device.

[0037] (5) The base, cone and shell of the present invention are rigidly connected, and the wave motion is directly transmitted to the energy harvesting unit. There is no intermediate transmission link, the energy loss is low, the response speed is fast, the overall structure is compact and the size is small, which is suitable for in-situ integration of buoys and marine ranching equipment.

[0038] (6) The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A gradient frustum array multi-degree-of-freedom omnidirectional piezoelectric power generation device, characterized by, The system includes a coaxially sealed floating shell, an internal gradient frustum array skeleton unit, multiple orthogonally arranged vibration energy harvesters, and a matching power management module. The gradient frustum array skeleton unit is a three-layer coaxially arranged frustum structure. Each frustum has a cubic support base at its center, which is rigidly connected to the inner wall of the corresponding frustum via four radial support rods. On each of the six faces of each cubic support base, one set of vibration energy harvesters is vertically mounted along the three orthogonal axes (X, Y, Z), forming three pairs of completely symmetrical, spatially decoupled omnidirectional energy harvesting arrays. The outer ends of the vibration energy harvesters are rigidly connected to the inner wall of the floating shell, and they integrate a magnetically coupled displacement amplification and limiting mechanism and a flexible compression transducer. The power management module is electrically connected to all the flexible compression transducers.

2. The gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device according to claim 1, characterized in that, The floating outer shell is buoy-shaped with a larger top and a smaller bottom, and its central axis coincides with the central axis of the gradient frustum array skeleton unit.

3. The gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device according to claim 1, characterized in that, The gradient frustum array skeleton unit is a three-layer coaxial vertically arranged hollow frustum structure, consisting of an upper high-frequency response frustum, a middle mid-frequency response frustum, and a lower low-frequency response frustum from top to bottom. The bottom diameter of the three frustums increases in a ratio of 1:1.5:2, the frustum angle is 30°-60°, the interlayer spacing is 1 / 3-1 / 2 of the total height of the frustum, and the wall thickness and material elastic modulus increase sequentially from top to bottom. The vibration energy harvester of the upper frustum covers the natural frequency of 3-5Hz, the middle layer covers 1-3Hz, and the lower layer covers 0.5-1Hz, with the three layers working together to achieve full-frequency coverage of 0.5-5Hz. The vibration energy harvesters of the three frustums are arranged in a 60° staggered arrangement in the circumferential direction to avoid interlayer vibration coupling interference.

4. The gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device according to claim 1, characterized in that, The cubic support base is located at the geometric center of the corresponding frustum. Four radial support rods are evenly distributed along the circumference of the frustum, and their two ends are welded and fixed to the side wall of the base and the inner wall of the frustum, respectively, so as to realize the rigid synchronous movement of the base, the frustum and the floating shell.

5. The gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device according to claim 1, characterized in that, The six faces of the cubic support base correspond to the six directions of the spatial rectangular coordinate system: X+, X-, Y+, Y-, Z+, and Z-. The vibration energy collectors in each axis vibrate independently and do not interfere with each other, achieving synchronous capture of omnidirectional wave energy with six degrees of freedom. The Z-axis vibration energy collector has a longer cantilever beam and a heavier magnetic mass, making it suitable for low-frequency vertical waves of 0.5-2Hz. The X-axis and Y-axis vibration energy collectors have shorter cantilever beams and higher stiffness, making them suitable for high-frequency transverse waves of 2-5Hz.

6. The gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device according to claim 5, characterized in that, The vibration energy harvester consists of a rectangular fixed frame, a cantilever beam, a magnetic mass block, two sets of fixed magnets, and two sets of flexible compression transducers. The outer side of the rectangular fixed frame is rigidly connected to the inner wall of the floating shell, and the inner side is rigidly connected to the corresponding surface of the cubic support base. The root of the cantilever beam is rigidly fixed to the middle of the inner side of the rectangular fixed frame, with the free end facing the center of the fixed frame, and the magnetic mass block is fixed to the free end of the cantilever beam. The two sets of fixed magnets are respectively fixed at the upper and lower corners of one side of the rectangular fixed frame, arranged opposite to the magnetic mass block with the same pole, forming a nonlinear magnetic repulsion mechanism. The two sets of flexible compression transducers are respectively fixed at the two corners of the other side of the rectangular fixed frame, symmetrically arranged on both sides of the cantilever beam, and the driving end abuts against the side of the cantilever beam.

7. The gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device according to claim 6, characterized in that, The flexible compression transducer consists of a clamping frame and a multi-layer piezoelectric ceramic stack, which is arranged along the transducer axis. The clamping frame includes a rhomboid shell and fastening screws for fixing the piezoelectric ceramic stack and applying preload. When the cantilever beam vibrates, the rhomboid shell pushes the piezoelectric ceramic stack to generate axial compression deformation. The multi-layer piezoelectric ceramic stack adopts the d33 piezoelectric working mode.

8. The gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device according to claim 6, characterized in that, The magnetic coupling displacement amplification and limiting mechanism amplifies the minute bending displacement of the cantilever beam by using the nonlinear magnetic repulsion between the magnetic mass block and the fixed magnet, thus widening the frequency band coverage of a single collector and forming a non-contact limiting mechanism to prevent fatigue damage to the cantilever beam and excessive compression of the piezoelectric ceramic.

9. The gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device according to claim 1, characterized in that, The power management module circuit consists of a rectifier bridge, a supercapacitor, and an energy storage battery. The supercapacitor is used for voltage stabilization, and after charging is completed, the power is stored in the energy storage battery; the battery regulates the charging frequency.

10. The gradient frustum array type multi-degree-of-freedom omnidirectional piezoelectric power generation device according to claim 3, characterized in that, The device moves and rotates in the X, Y, and Z directions with the nearshore waves. Waves of different frequencies excite the vibration energy collectors of the corresponding gradient layer cones to resonate. The vibration of the cantilever beam drives the flexible compression transducer to convert wave energy into electrical energy. After being processed by the power management module, the electrical energy is stored or directly drives marine monitoring equipment and intelligent marine ranching equipment.

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