A vibration energy harvesting and self-powered vibration monitoring device

Abstract

The vibration energy collecting and self-powered vibration monitoring device provided by the embodiments of the present disclosure comprises: a stator fixedly connected with a vibration object; a mover capable of reciprocating along the vibration direction of the vibration object relative to the stator; a guide mechanism connected between the stator and the mover, used for transmitting the vibration energy transmitted to the stator to the mover, so as to drive the mover to reciprocate along the vibration direction of the vibration object; a friction power generation unit arranged between the stator and the mover, used for converting the mechanical energy generated when the mover reciprocates along the vibration direction relative to the stator into a first electric signal; a friction sensing unit arranged between the stator and the mover, used for converting the mechanical energy into a second electric signal; and a signal processing unit, used for performing signal processing on the second electric signal to obtain the vibration frequency of the vibration object. The monitoring device of the embodiments of the present disclosure has both energy supply and frequency monitoring functions, and has high measurement accuracy.

Description

Technical Field

[0001] This disclosure relates to the field of energy harvesting and self-powered sensing, and more particularly to a vibration energy harvesting and self-powered vibration monitoring device. Background Technology

[0002] High-speed railways, as a crucial component of the transportation system, play a vital role in economic and social development due to their high speed and large capacity. Railway bridges are essential infrastructure for high-speed railways; however, with the ever-increasing volume of transportation, many high-speed railway bridges are operating under overload conditions. Prolonged overload operation leads to accelerated fatigue, corrosion, material aging, and component damage in high-speed railway bridges. Therefore, monitoring the health status of high-speed railway bridges has a significant impact on the smooth operation and safety of high-speed trains.

[0003] Currently, sensors used for health monitoring of high-speed railway bridges are typically powered by chemical batteries. However, these batteries have low capacity and are difficult to recycle and dispose of properly. Furthermore, most are located in remote areas far from cities, resulting in high long-term monitoring and maintenance costs. Harvesting energy from the environment surrounding high-speed railway bridges to power various sensors is considered a possible solution. In the engineering environment of high-speed railway bridges, wind, solar, acoustic, and vibration energy can all be utilized. In contrast, except for vibration energy, other energy sources are severely limited by the natural environment. Furthermore, the collected vibration energy can be further analyzed to extract the vibration frequency of the high-speed railway bridge. Monitoring the vibration frequency of high-speed railway bridges helps assess their structural health, extend their service life, and prevent catastrophic accidents.

[0004] Based on the above needs, existing vibration energy harvesting devices, such as Chinese invention patent application CN 115483845 A, disclose an arrayed electromagnetic-friction composite vibration energy harvesting device, comprising: a shell; a vibration energy harvesting mechanism, including multiple vibration energy harvesting units arranged in an array within the shell, each vibration energy harvesting unit including a spring-loaded vibration pickup unit, an electromagnetic power generation unit, and a triboelectric power generation unit; the spring-loaded vibration pickup unit includes a pickup body and multiple springs. This device, by introducing an electromagnetic-friction composite vibration energy harvesting structure, can convert vibration excitation from any external direction into electrical energy output; furthermore, the arrayed design broadens the device's operating frequency band.

[0005] The drawback of this device is that triboelectric power generation and electromagnetic power generation have different output characteristics in converting vibration energy into electrical energy, and therefore cannot be directly superimposed. The high voltage and low current characteristics of triboelectric power generation and the low voltage and high current characteristics of electromagnetic power generation are not well coupled, resulting in low energy conversion efficiency.

[0006] Based on the above requirements, existing vibration energy harvesting devices, such as Chinese invention patent application CN 113162456 A, provide a triboelectric nanogenerator that integrates power supply and sensing, including: a first electrode, a second electrode, a third electrode and a triboelectric medium layer.

[0007] The drawback of this device is that, due to its simple structure, it does not constrain the degrees of freedom in directions other than the vibration direction (such as the vertical direction), and the output will be affected by vibrations in other directions, such as horizontal vibrations, which will lead to inaccurate frequency measurement.

[0008] Therefore, a new energy harvesting technology is needed to solve the energy supply problem in high-speed railway bridges, and a self-powered frequency monitoring device that does not require an energy supply is also needed. Summary of the Invention

[0009] This disclosure aims to address at least one of the technical problems existing in the prior art.

[0010] Therefore, this disclosure provides a vibration energy harvesting and self-powered vibration monitoring device that combines power supply and frequency monitoring functions, and offers high measurement accuracy. The monitoring device includes:

[0011] The stator is fixedly connected to the vibrating object to transmit the vibration energy of the vibrating object to the stator;

[0012] The mover can reciprocate relative to the stator along the vibration direction of the vibrating object;

[0013] A guiding mechanism, connected between the stator and the mover, is used to transfer the vibration energy transmitted to the stator to the mover, so as to drive the mover to reciprocate along the vibration direction of the vibrating object;

[0014] A triboelectric power generation unit is disposed between the stator and the rotor, and is used to convert the mechanical energy generated when the rotor reciprocates relative to the stator along the vibration direction of the vibrating object into a first electrical signal, thereby forming the first electrical energy output to the outside.

[0015] A friction sensing unit, disposed between the stator and the mover, is used to convert the mechanical energy generated when the mover reciprocates relative to the stator along the vibration direction of the vibrating object into a second electrical signal; and

[0016] The signal processing unit is used to process the second electrical signal to obtain the vibration frequency of the vibrating object.

[0017] Optionally, the stator includes a stator base plate, a stator top plate, and a plurality of stator partitions arranged in parallel and spaced layers, and a stator side plate connecting the stator base plate, the stator top plate, and all stator partitions into a whole. During the movement of the stator with the vibrating object, the stator base plate, stator side plate, stator top plate, and all stator partitions remain relatively stationary. The mover includes a mover base plate, mover top plate, and a plurality of mover partitions arranged in parallel and spaced layers, and a mover side plate connecting the mover base plate, the mover top plate, and all mover partitions into a whole. During the reciprocating motion of the mover relative to the stator along the vibration direction of the vibrating object, the mover base plate, mover side plate, mover top plate, and all mover partitions remain relatively stationary. Except for the side plate, the remaining plates in the stator and the mover are arranged in parallel and staggered order to form an interdigitated shape.

[0018] Optionally, the guiding mechanism includes a spring, a guide rod, a linear bearing, a spring flange, and a linear bearing flange; the guide rod is distributed at each corner of the stator and the mover, the bottom end of the guide rod is fixedly connected to the stator base plate, and the top end of the guide rod is fixedly connected to the inner hole of a corresponding spring flange; the bottom of each spring flange is fixedly connected to the top end of a corresponding spring, and the top end of each spring flange is fixedly connected to the bottom end of the mover top plate; the corner of the top end of the mover top plate is fixedly connected to a linear bearing flange, and each linear bearing is fixed in the inner hole of a corresponding linear bearing flange, the outer diameter of the linear bearing matching the inner diameter of the linear bearing flange; the spring is sleeved on the outside of a corresponding guide rod, and the bottom end of the spring is fixedly connected to the stator base plate.

[0019] Optionally, the triboelectric power generation unit is a contact-separated type, disposed between the stator partition and the rotor partition on opposite sides. It includes a first elastic layer, a first electrode layer, and a first friction layer fixedly disposed on the rotor partition facing the stator partition and stacked sequentially, and a second elastic layer, a second electrode layer, and a second friction layer fixedly disposed on the stator partition facing the rotor partition and stacked sequentially. The first elastic layer is disposed closer to the rotor partition than the first friction layer, and the second elastic layer is disposed closer to the stator partition than the second friction layer. The first friction layer and the second friction layer are made of materials with different electron gain and loss capabilities. During the reciprocating motion of the rotor relative to the stator along the vibration direction, the first electrical signal is generated between the first electrode layer and the second electrode layer.

[0020] Optionally, the friction sensing unit is disposed between the stator top plate and the mover top plate on opposite sides, and includes a third elastic layer and a third electrode layer fixedly disposed on the mover top plate facing the stator top plate and stacked thereon, and a fourth elastic layer, a fourth electrode layer and a third friction layer fixedly disposed on the stator top plate facing the mover top plate and stacked thereon in sequence. The third elastic layer is positioned closer to the mover top plate than the third electrode layer, and the fourth elastic layer is positioned closer to the stator top plate than the third friction layer. The third friction layer is made of a material with a different electron gain / loss capability than the third electrode layer. During the reciprocating motion of the mover relative to the stator along the vibration direction, the second electrical signal generated between the third electrode layer and the fourth electrode layer is acquired using a data acquisition card.

[0021] Optionally, the signal processing unit performs signal processing on the second electrical signal, including filtering and Fourier transforming the second electrical signal.

[0022] Optionally, the monitoring device further includes an electromagnetic power generation unit disposed between the stator and the rotor, used to convert the mechanical energy generated when the rotor reciprocates relative to the stator along the vibration direction of the vibrating object into a third electrical signal, thereby forming a second electrical energy output to the outside.

[0023] Optionally, a set of electromagnetic power generation units may be provided between the stator base plate and the moving base plate on opposite sides, and / or between the stator top plate and the moving top plate on opposite sides;

[0024] Each electromagnetic power generation unit includes an induction coil and a magnet. During the reciprocating motion of the mover relative to the stator along the vibration direction, the distance between the magnet and the induction coil periodically increases or decreases.

[0025] Optionally, each set of electromagnetic power generation units is provided with multiple corresponding induction coils and magnets.

[0026] Optionally, the measuring device further includes an improved step-down circuit, which includes a rectifier bridge, a gas discharge tube, a diode, and an LC oscillation circuit. The AC terminal of the rectifier bridge is connected to the output terminals of the triboelectric generator unit and the electromagnetic generator unit. The positive terminal of the rectifier bridge is connected to one end of the gas discharge tube. The positive terminal of the diode and one end of the inductor in the LC oscillation circuit are connected to the other end of the gas discharge tube. The other end of the inductor is connected to the positive terminal of the capacitor in the LC oscillation circuit. The negative terminal of the capacitor and the positive terminal of the diode are connected to the negative terminal of the rectifier bridge. The capacitor is connected to the load.

[0027] Compared with the prior art, this disclosure has the following characteristics and beneficial effects:

[0028] 1. By introducing the principles of triboelectric charging and electrostatic induction, the vibration energy of a vibrating object (such as a high-speed railway bridge) is converted into electrical energy, realizing self-driving performance. The electrical signal can also be output as a sensing signal to extract and analyze the frequency in the vibration signal, providing a basis for abnormal vibration monitoring of the vibrating object.

[0029] 2. Use guide rods and linear bearings to avoid the influence of other angular vibrations on frequency measurement.

[0030] 3. By coupling the high voltage characteristics of triboelectric power generation with the high current characteristics of electromagnetic power generation through an improved step-down circuit, the advantages of both are combined to achieve a high power density over a wide frequency range.

[0031] 4. This device has both power supply and frequency monitoring functions. Compared with existing technologies, this device is more integrated and has a more compact structure.

[0032] 5. The electrical signal generated by the friction sensing unit has low voltage characteristics, so there is no need for subsequent voltage reduction processing. The electrical signal generated by the friction sensing unit can be directly used for signal acquisition. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a three-dimensional structural schematic diagram of a vibration energy harvesting and self-powered vibration monitoring device provided in this embodiment;

[0035] Figure 2 for Figure 1 A frontal view of the monitoring device shown.

[0036] Figure 3 for Figure 2 The partial view A described in the text;

[0037] Figure 4 for Figure 3 The cross-sectional view CC described in the document;

[0038] Figure 5 for Figure 2 The cross-sectional view DD described in the document;

[0039] Figure 6 for Figure 5 The partial view B described in the text;

[0040] Figure 7 for Figure 5 The partial view C described in the text;

[0041] Figure 8 for Figure 2 The cross-sectional view EE described in the document;

[0042] Figure 9 This is an exploded view of the electromagnetic power generation unit in the monitoring device provided in this embodiment;

[0043] Figure 10 This is a schematic diagram of the improved step-down circuit in the monitoring device provided in this embodiment;

[0044] Figure 11 The diagram shows the output open-circuit voltage of the monitoring device provided in this embodiment under different frequency excitations.

[0045] Figure 12 The output power density of the monitoring device provided in this embodiment under different frequency excitations;

[0046] Figure 13 The output signal spectrum of the monitoring device provided in this embodiment under different frequency excitations;

[0047] Figure 14 The image shows a fitting plot of the measured frequency and the actual frequency obtained by the monitoring device provided in this embodiment.

[0048] Figure 15 Error diagram between measured frequency and actual frequency obtained by the monitoring device provided in this embodiment;

[0049] In the diagram: 1. Stator; 2. Mover; 3. Guide mechanism; 4. Electromagnetic power generation unit; 5. Triboelectric power generation unit; 6. Triboelectric sensing unit; 8. Cover plate; 101. Stator base plate; 102. Stator side plate; 102a. First protrusion; 102b. Second protrusion; 103. Stator top plate; 104. Stator partition plate; 201. Mover base plate; 202. Mover side plate; 203. Mover top plate; 204. Mover partition plate; 301. Spring flange; 302. Linear bearing flange; 303. Guide rod; 304. Spring; 305. Linear bearing; 3 06. Nut; 307. Bolt; 401. Magnet; 402. Induction coil; 501a. First elastic layer; 501b. Second elastic layer; 502a. First electrode layer; 502b. Second electrode layer; 503a. First friction layer; 503b. Second friction layer; 601a. ​​Third elastic layer; 601b. Fourth elastic layer; 602a. Third electrode layer; 602b. Fourth electrode layer; 603. Third friction layer; 701. Rectifier bridge; 702. Gas discharge tube; 703. Inductor; 704. Capacitor; 705. Diode. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application.

[0051] Conversely, this application covers any alternatives, modifications, equivalent methods, and schemes made within the spirit and scope of this application as defined by the claims. Furthermore, to provide the public with a better understanding of this application, certain specific details are described in detail below. However, this application can be fully understood by those skilled in the art even without these detailed descriptions.

[0052] like Figure 1 As shown in the embodiments of this disclosure, a vibration energy harvesting and self-powered vibration monitoring device is provided. This device aims to harvest vibration energy and convert it into electrical energy to power electrical equipment. Simultaneously, it extracts and analyzes the frequency in the vibration signal to provide a basis for monitoring abnormal vibrations. The monitoring device includes:

[0053] Stator 1 is fixedly connected to the vibrating object (i.e., the object being monitored and capable of generating vibrational motion) to transmit the vibrational energy of the vibrating object to stator 1;

[0054] The mover 2 can reciprocate relative to the stator 1 along the main vibration direction of the vibrating object;

[0055] The guide mechanism 3 is connected between the stator 1 and the mover 2 and is used to transfer the vibration energy transmitted to the stator 1 to the mover 2 so as to drive the mover 2 to reciprocate along the vibration direction of the vibrating object.

[0056] The triboelectric generator unit 5 is disposed between the stator 1 and the rotor 2. It is used to convert the mechanical energy generated when the rotor 2 reciprocates relative to the stator 1 along the vibration direction of the vibrating object into a first electrical signal, thereby forming the first electrical energy output to the outside.

[0057] Friction sensing unit 6, disposed between stator 1 and rotor 2, is used to convert the mechanical energy generated when rotor 2 reciprocates relative to stator 1 along the vibration direction of the vibrating object into a second electrical signal; and

[0058] The signal processing unit (not shown in the figure) is used to process the second electrical signal to obtain the vibration frequency of the vibrating object.

[0059] Optionally, see Figure 1The stator 1 and rotor 2, as the main frame of the monitoring device provided in this embodiment, adopt a layered structure. The stator 1 includes a stator base plate 101, a stator top plate 103, and a plurality of stator partitions 104 arranged in parallel layers, and a stator side plate 102 connecting the stator base plate 101, the stator top plate 103, and all the stator partitions 104 into a whole. During the movement of the stator 1 with the vibrating object, the stator base plate 101, the stator side plate 102, the stator top plate 103, and all the stator partitions 104 remain relatively stationary. The arrangement direction of the stator base plate 101, the stator top plate 103, and the stator partitions 104 is consistent with the vibration direction of the vibrating object. The mover 2 includes a layered and parallel mover base plate 201, a mover top plate 203, and several mover partitions 204, as well as a mover side plate 202 that connects the mover base plate 201, the mover top plate 203, and all the mover partitions 204 into a whole. During the reciprocating motion of the mover 2 relative to the stator 1 along the vibration direction of the vibrating object, the mover base plate 201, the mover side plate 202, the mover top plate 203, and all the mover partitions 204 remain relatively stationary. The arrangement direction of the mover base plate 201, the mover top plate 203, and the mover partitions 204 is consistent with the vibration direction of the vibrating object. Except for the side plates, all other plates in the stator 1 and mover 2 are arranged in parallel and staggered order to form an interdigitated shape. Specifically, from bottom to top, they are stator base plate 101, mover base plate 201, stator partition plate 104, mover partition plate 204, stator partition plate 104, mover partition plate 204, ..., stator top plate 103 and mover top plate 203, meaning that each plate in the mover 2 is located above the corresponding plate in the stator 1. It can be understood that the height dimensions (i.e., dimensions along the vibration direction) of the stator side plate 102 and the mover side plate 202 can be the same, but the top and bottom of the mover side plate 202 are higher than the top and bottom of the stator side plate 102. Specifically, the difference is the difference between the distance from the stator base plate 101 to the stator top plate 103 and the distance from the mover base plate 201 to the mover top plate 203. The stator 1 and mover 2 are arranged in layers, which makes the monitoring device of this embodiment of the present disclosure easy to disassemble and assemble, and very convenient to repair and replace materials. In addition, the multi-layer structure increases the output energy density.

[0060] In one embodiment of this application, the stator 1 is provided with one stator base plate 101 and one stator top plate 103, two symmetrically arranged stator side plates 102, and three identical stator partitions 104. Three L-shaped first protrusions 102a are spaced apart in the middle of the stator side plate 102 facing the stator partitions 104. Figure 1 It is not indicated in the text that, Figure 5The image shows the L-shaped first protrusion. An L-shaped first protrusion 102a is provided at the top and bottom of the stator side plate 102 facing the stator partition 104. A first groove corresponding to the L-shaped first protrusion 102a is provided on all stator partitions 104, stator top plate 103 and stator bottom plate 101. Each stator partition 104, stator bottom plate 101 and stator top plate 103 achieves a stable connection with the stator side plate 102 through the cooperation of the L-shaped first protrusion 102a and the first groove, thereby ensuring the relative static state between the stator bottom plate 101, stator side plate 102, stator top plate 103 and all stator partitions 104. Similarly, the mover 2 is provided with one mover base plate 201 and one mover top plate 203, two symmetrically arranged mover side plates 202, and three identical mover partitions 204. Three L-shaped protrusions are spaced apart in the middle of the mover side plate 202 facing the mover partition 204. An L-shaped second protrusion 102b is provided at the top and bottom of the mover side plate 202 facing the mover partition 204. A second groove corresponding to the L-shaped second protrusion 102b is provided on all the mover partitions 204, the mover top plate 203, and the mover base plate 201. Each mover partition 204, the mover base plate 201, and the mover top plate 203 are stably connected to the mover side plate 202 through the cooperation of the L-shaped second protrusion 102b and the second groove, thereby ensuring the relative stillness between the mover base plate 201, the mover side plate 202, the mover top plate 203, and all the mover partitions 204. The base plate, top plate, and partition plate in stator 1 and mover 2 are all square flat plates.

[0061] Optionally, such as Figures 2-4As shown, the guide mechanism 3 includes a spring 304, a guide rod 303, a linear bearing 305, a spring flange 301, a linear bearing flange 302, a nut 306, and a bolt 307. A guide rod 303 is provided at each corner of the main frame of the monitoring device provided in this embodiment. The bottom end of each guide rod 303 is fixedly connected to the stator base plate 101 by an interference fit. The top end of each guide rod 303 is fixedly connected to the inner hole of a corresponding spring flange 301 by an interference fit. The bottom of each spring flange 301 is fixedly connected to the top end of a corresponding spring 304. The top end of each spring flange 301 is fixed to the bottom end of the mover top plate 203 by four bolts 307 and nuts 306. The corner of the top end of the mover top plate 203 is fixedly connected to a linear bearing flange 302 by four bolts 307 and nuts 306. Each linear bearing 305 is fixed in the inner hole of a corresponding linear bearing flange 302. The outer diameter of the linear bearing 305 is equal to the inner diameter of the linear bearing flange 302. Each spring 304 is respectively sleeved on the outside of a corresponding guide rod 303, and the bottom end of each spring 304 is fixedly connected to the stator base plate 101. The spring 304 connects the mover 2 and the stator 1, allowing the mover 2 and the stator 1 to reciprocate relative to each other in the vertical direction along the guide rod 303. Specifically, the vibration energy transmitted from the vibrating object to the stator base plate 101 is first transmitted sequentially through the guide rod 303, the linear bearing 305, and the linear bearing flange 302 to the mover top plate 203. The mover top plate 203 drives the mover side plate 202, thereby driving the mover partition 204 to move. The guide mechanism 3 ensures that the mover moves only in the vertical direction, avoiding vibration interference in other directions.

[0062] Optionally, to make the structure of the monitoring device in this embodiment more stable, the top ends of all the guide rods 303 of the guide mechanism 3 are connected by a cover plate 8.

[0063] Optionally, such as Figure 5 , 6As shown, the triboelectric power generation unit 5 is disposed between the stator partition 104 and the mover partition 204 on opposite sides. It includes a first elastic layer 501a, a first electrode layer 502a, and a first friction layer 503a fixedly disposed on the mover partition 204 facing the stator partition 104 and stacked in sequence, and a second elastic layer 501b, a second electrode layer 502b, and a second friction layer 503b fixedly disposed on the stator partition 104 facing the mover partition 204 and stacked in sequence. The first elastic layer 501a is disposed closer to the mover partition 204 than the first friction layer 503a, and the second elastic layer 501b is disposed closer to the stator partition 104 than the second friction layer 503b. In a single triboelectric power generation unit 5, the first elastic layer 501a and the second elastic layer 501b can be made of the same or different elastic materials, the first electrode layer 502a and the second electrode layer 502b can be made of the same or different conductive materials (preferably metal materials with good conductivity), and the first friction layer 503a and the second friction layer 503b are made of materials with different electron gain and loss capabilities. During the reciprocating motion of the mover 2 relative to the stator 1 along the vibration direction, the first friction layer 503a and the second friction layer 503b come into contact with and separate from each other. The first elastic layer 501a and the second elastic layer 501b ensure sufficient contact between the first friction layer 503a and the second friction layer 503b. The first electrode layer 502a and the second electrode layer 502b, as electrodes, induce a changing electromotive force. When the first electrode layer 502a and the second electrode layer 502b are connected in the form of an external load, a current, i.e., a first electrical signal, is generated between the first electrode layer 502a and the second electrode layer 502b, thereby realizing the charging of the capacitor to store electrical energy for energy collection and conversion. In one embodiment of this application, five triboelectric power generation units 5 are provided in parallel. In each triboelectric power generation unit 5, the elastic layer is made of EVA sponge strip with a thickness of 2 mm, the electrode layer is made of copper foil with a thickness of 0.1 mm, the first friction layer 503a is made of polyamide film with a thickness of 0.05 mm, and the second friction layer 503b is made of fluorinated ethylene propylene polymer film with a thickness of 0.08 mm. The cross-sectional dimensions of the EVA sponge strip, copper foil, polyamide film, and fluorinated ethylene propylene polymer film are the same, all being 64 mm × 76 mm.

[0064] Optionally, such as Figure 7As shown, the friction sensing unit 6 is disposed between the stator top plate 103 and the mover top plate 203 on opposite sides. It includes a third elastic layer 601a and a third electrode layer 602a fixedly disposed on the mover top plate 203 facing the stator top plate 103 and stacked thereon, and a fourth elastic layer 601b, a fourth electrode layer 602b and a third friction layer 603 fixedly disposed on the stator top plate 103 facing the mover top plate 203 and stacked thereon in sequence. The third elastic layer 601a is disposed closer to the mover top plate 203 than the third electrode layer 602a, and the fourth elastic layer 601b is disposed closer to the stator top plate 103 than the third friction layer 603. The third elastic layer 601a and the fourth elastic layer 601b in the friction sensing unit 6 can be made of the same or different elastic materials, and the third electrode layer 602a and the fourth electrode layer 602b can be made of the same or different conductive materials (preferably metal materials with good conductivity). The third friction layer 603 is made of a material with different electron gain and loss capabilities than the third electrode layer 602a. During the reciprocating motion of the mover 2 relative to the stator 1 along the vibration direction, the third electrode layer 602a acts as both a friction material and a sensing electrode, coming into contact with and separating from the third friction layer 603. The third electrode layer 602a and the fourth electrode layer 602b, as electrodes, induce a changing electromotive force. By connecting the third electrode layer 602a and the fourth electrode layer 602b to a data acquisition card, the second electrical signal can be acquired in real time. Subsequently, the signal processing unit filters and performs Fourier transform on the acquired second electrical signal to obtain the frequency of the vibrating object. In one embodiment of this application, only one friction sensing unit 6 is provided. The elastic layer is made of EVA sponge strip with a thickness of 2mm, the electrode layer is made of copper foil with a thickness of 0.1mm, and the friction layer is made of fluorinated ethylene propylene polymer film with a thickness of 0.08mm. The cross-sectional dimensions of the EVA sponge strip, copper foil, and fluorinated ethylene propylene polymer film are all the same, but their area is one-quarter of the cross-sectional area of ​​a single triboelectric power generation unit 5. The second electrical signal (i.e., vibration signal) output by the friction sensing unit 6 is about 3V. Therefore, the collected second electrical signal can be directly connected to the signal processing circuit for use without the need for additional voltage processing circuit.

[0065] Optionally, such as Figure 8 , 9As shown, the monitoring device provided in this embodiment further includes an electromagnetic power generation unit 4, which is disposed between the stator 1 and the rotor 2. This unit converts the mechanical energy generated when the rotor 2 reciprocates relative to the stator 1 along the vibration direction of the vibrating object into a third electrical signal, thereby forming a second electrical energy output externally. Further, this embodiment provides two sets of electromagnetic power generation units 4. One set is disposed between the stator base plate 101 and the rotor base plate 201 on opposite sides, and the other set is disposed between the stator top plate 103 and the rotor top plate 203 on opposite sides. The two sets of electromagnetic power generation units 4 have the same structure. The set disposed between the stator base plate 101 and the rotor base plate 201 will be described as an example. The electromagnetic power generation unit 4 includes an induction coil 401 fixedly disposed on the stator base plate 101 and a magnet 402 fixedly disposed on the rotor base plate 201. During the reciprocating motion of the mover 2 relative to the stator 1 along the vibration direction, the mover base plate 201 drives the magnet 402 to move, and the stator base plate 101 drives the induction coil 401 to move. This causes the distance between the magnet 402 and the induction coil 401 to periodically increase or decrease, thereby changing the magnetic flux distribution in the induction coil 401. Specifically, as the distance between the magnet 402 and the induction coil 401 gradually increases, an induced current will be generated in the induction coil 401 according to Lenz's law to resist this change. The gradually increasing magnetic flux in the induction coil 401 generates an induced current, which is then conducted through a wire as a second source of electrical energy to power electrical equipment. The output of the electromagnetic power generation unit 4 features low voltage and high current.

[0066] Furthermore, to increase the output voltage and current of the electromagnetic power generation unit 4, each electromagnetic power generation unit 4 may be equipped with multiple induction coils 401 and corresponding magnets 402, with the multiple induction coils 401 connected in series, such as... Figure 9 As shown, each electromagnetic power generation unit 4 is provided with multiple induction coils 401 and corresponding magnets 402, and the multiple induction coils 401 and corresponding magnets 402 are evenly distributed between the stator base plate 101 and the mover base plate 201. In one embodiment of this application, each electromagnetic power generation unit 4 is provided with 4 induction coils 401 and 4 magnets 402. The outer diameter of each induction coil 401 is 30mm, the inner diameter is 2mm, the wire diameter is 0.15mm, and the number of turns is 1000. The diameter of each magnet 402 is 30mm and the thickness is 2mm.

[0067] Optionally, such as Figure 10As shown, the monitoring device provided in this embodiment further includes an improved step-down circuit. This circuit uses a gas discharge tube 702 as a fast switch for the LC oscillation circuit. It includes a rectifier bridge 701, a gas discharge tube 702, a diode 705, and an LC oscillation circuit. The output terminals of the triboelectric power generation unit 5 and the electromagnetic power generation unit 4 are both connected to the AC terminal of the rectifier bridge 701. The positive terminal of the rectifier bridge 701 is connected to one end of the gas discharge tube 702. The positive terminal of the diode 705 and one end of the inductor 703 in the LC oscillation circuit are connected to the other end of the gas discharge tube 701. The other end of the inductor 703 is connected to the positive terminal of the capacitor 704 in the LC oscillation circuit. The negative terminal of the capacitor 704 and the positive terminal of the diode 705 are connected to the negative terminal of the rectifier bridge 701. The positive terminal of the load is connected to the positive terminal of the capacitor 704, and the negative terminal of the load is connected to the negative terminal of the capacitor 704. The voltages output by the triboelectric power generation unit 5 and the electromagnetic power generation unit 4 are first rectified by the rectifier bridge 701. When the rectified voltage is higher than the threshold voltage of the gas discharge tube 702, the gas discharge tube 702 is broken down. At this time, the diode 705 is not conducting, the LC oscillation circuit is connected to the gas discharge tube 702, and the triboelectric power generation unit 5 and the electromagnetic power generation unit 4 are in a conducting state with the LC oscillation circuit; one end of the inductor 703 in the LC oscillation circuit ( Figure 10 The potential shown is at the left end, which is the same as the positive potential of the rectifier bridge 701. The other end of the inductor 703 (shown on the left) Figure 10 (As shown on the right) The potential is the same as the potential of the positive terminal of the load. At this time, the current of inductor 703 increases linearly. Simultaneously, the circuit charges capacitor 704, providing energy to the load. When the rectified voltage is lower than the threshold voltage of gas discharge tube 702, gas discharge tube 702 is not broken down, and the triboelectric power generation unit 5 and electromagnetic power generation unit 4 are in a non-conductive state with the LC oscillation circuit. At this time, inductor 703 generates a reverse electromotive force due to its freewheeling effect, diode 705 conducts with the LC oscillation circuit, and inductor 703 acts as the power source in the closed circuit to supply power to the load. During the discharge process, the current in inductor 703 decreases linearly. This improved step-down circuit, on the one hand, acts as a voltage drop, converting the high voltage of triboelectric power generation unit 5 into a low voltage; on the other hand, through the switching characteristics of gas discharge tube 702, this improved step-down circuit can convert pulse voltage and current into stable DC voltage and current.

[0068] It is understood that the improved step-down circuit provided in this embodiment can complement the advantages and disadvantages of the output characteristics (i.e., high voltage and low current) of the triboelectric power generation unit 5 and the output characteristics (i.e., low voltage and high current) of the electromagnetic power generation unit 4, resulting in better coupling effect.

[0069] The following is the working process of the monitoring device provided in the embodiments of this disclosure:

[0070] When the monitoring device of this embodiment is used, the stator base plate 101 of the monitoring device is connected and fixed to the bridge deck of the high-speed railway bridge being monitored. When a train passes by, the high-speed railway bridge vibrates. This vibration is transmitted to the stator base plate 101, and then transmitted to the linear bearing flange 302 through the spring 304. The linear bearing flange 302 and the linear bearing 305 transmit the vibration signal to the mover top plate 203. The mover top plate 203 continuously compresses and stretches the spring 304, generating forced vibration. The mover top plate 203 drives the mover... The partition 204 and the mover side plate 202 reciprocate up and down along the guide rod 303, causing the mover partition 204 and the stator partition 104 to undergo contact separation along the guide rod direction (vertical direction shown in the figure), i.e., the vibration direction. This causes the first friction layer 503a and the second friction layer 503b of the triboelectric generator unit 5 to contact and separate. According to the principle of triboelectric generation, due to the different electron affinity of different materials, the surface of the first friction layer 503a will carry a positive charge, and the surface of the second friction layer 503b will carry an equal amount of negative charge. Due to the principle of electrostatic shielding, no induced charge will be generated on the first electrode layer 502a and the second electrode layer 502b at this time. When vibration is applied to the stator partition 104, due to the principle of electrostatic induction, electrons on the second electrode layer 502b flow from the external circuit to the first electrode layer 502a. Therefore, the first electrode layer 502a carries a negative charge, and the second electrode layer 502b carries a positive charge. Then, under the action of vibration, as the separation distance between the first friction layer 503a and the second friction layer 503b gradually increases, the potential difference between the first electrode layer 502a and the second electrode layer 502b gradually increases. The potential difference between the first electrode layer 502a and the second electrode layer 502b reaches its maximum when the separation distance is at its maximum. Subsequently, the first friction layer 503a gradually approaches the second friction layer 503b, the potential difference gradually decreases, and electrons flow from the first electrode layer 502a to the second electrode layer 502b. This cyclical motion generates the first electrical signal.

[0071] Simultaneously, the vertical contact separation of the mover top plate 203 and the stator top plate 103 causes the third electrode layer 602a and the third friction layer 603 of the friction sensing unit 6 to separate. Due to the different electron affinities of different materials, the surface of the third electrode layer 602a carries a positive charge, while the surface of the third friction layer 603 carries an equal amount of negative charge. When separation begins under vibration, electrons on the third electrode layer 602a flow from the external circuit to the fourth electrode layer 602b, thus the third electrode layer 602a becomes positively charged. Then, under the action of vibration, as the separation distance between the third friction layer 603 and the third electrode layer 602a gradually increases, the potential difference between the third electrode layer 602a and the fourth electrode layer 602b gradually increases. The potential difference reaches its maximum when the separation distance is at its maximum. Subsequently, the third friction layer 603 gradually approaches the third electrode layer 602a, the potential difference gradually decreases, and electrons flow from the fourth electrode layer 602b to the third electrode layer 602a. This cyclical motion generates a second electrical signal, which can reflect the vibration frequency information of the vibrating object.

[0072] Simultaneously, the vertical contact separation between the mover top plate 203 and the stator top plate 103, and between the mover bottom plate 201 and the stator bottom plate 101, causes the induction coil 402 and the magnet 401 of the electromagnetic power generation unit 4 to move vertically, cutting magnetic field lines, thus changing the magnetic flux distribution in the induction coil 402. As the distance between the magnet 401 and the induction coil 402 gradually increases, an induced current is generated in the induction coil 402 according to Lenz's law to resist this change, and the magnetic flux through the induction coil 402 gradually increases, generating an induced current in the induction coil 402. When the distance between the magnet 401 and the induction coil 402 reaches its maximum, the magnetic flux reaches its maximum value, and the induced current in the induction coil 402 reaches its maximum value. Similarly, when the magnetic flux through the induction coil 402 gradually decreases, a reverse current is induced in the induction coil 402. This cyclical movement generates a third electrical signal.

[0073] The first electrical signals generated by all triboelectric power generation units 5 in the device of this embodiment are connected in parallel and then connected to the AC output terminal of the rectifier bridge 701 in the improved step-down circuit. This allows the outputs of all triboelectric power generation units 5 to be connected to both ends of the load via the improved step-down circuit, thus supplying power to it. The third electrical signals generated by all induction coils 402 in the electromagnetic power generation unit 4 in the device of this embodiment are directly connected in series and then connected to the AC output terminal of the rectifier bridge 701 in the improved step-down circuit. After passing through the rectifier bridge 701, the capacitor 704 is charged. The positive terminal of the capacitor 704 is connected to the positive terminal of the load, and the negative terminal of the capacitor 704 is connected to the negative terminal of the load, enabling the capacitor 704 to supply power to the load.

[0074] The second electrical signal generated by the friction sensing unit 6 in this embodiment is directly connected to the data acquisition card. The data acquisition card is connected to a computer. A signal processing program is written using LabVIEW software on the computer to obtain the characteristic frequency of the second electrical signal and display it in real time.

[0075] To verify the power supply and frequency monitoring performance of the monitoring device provided in this embodiment, an experimental test was conducted on the monitoring device of this embodiment. The test results are as follows:

[0076] like Figure 11 , 12 As shown, the outputs of triboelectric generator 5 and electromagnetic generator 4 are rectified and connected in parallel. The combined peak open-circuit voltage can reach approximately 225V-380V. The maximum power density on the load under vibration at frequencies of 3Hz-25Hz was measured. It can be seen that the power density exhibits the best performance at 10Hz, approximately 2.8W / m. 3 Within the frequency range of 8Hz-25Hz, the maximum power density exceeds 1.69W / m². 3 This indicates that the monitoring device in this embodiment has high energy conversion efficiency and can operate stably over a wide frequency range.

[0077] like Figure 13 As shown, the second electrical signal generated by the friction sensing unit 6 at different vibration frequencies, which is acquired by the data acquisition card, is filtered and then subjected to a fast Fourier transform to extract the characteristic frequency of the signal, which is used as the measurement frequency.

[0078] like Figure 14 As shown, the measured frequency obtained from the friction sensing unit 6 is linearly fitted with the input vibration frequency, R 2 =0.99999, which indicates that the measured signal has good linearity and high consistency with the input signal, that is, the measurement accuracy of the monitoring device in this embodiment is high.

[0079] like Figure 15 As shown, the measured frequency obtained by Fourier transform of the friction sensing unit 6 is compared with the input vibration frequency. Within the range of 5-30Hz, the error rate of the frequency measurement is less than 0.9%. This indicates that the monitoring device of this embodiment has good performance for monitoring the frequency of high-speed railway bridges.

[0080] It should be noted that, in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0081] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

[0082] In the description of the embodiments of the present invention, it should be understood that the terms "top", "bottom", "up and down", "left and right", "coplanar", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0083] In the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "fixed connection", "fixed connection", "adhesion", "gluing", "bonding", "coating", "locking", etc., should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, etc. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0084] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A vibration energy harvesting and self-powered vibration monitoring device, characterized in that, include: The stator is fixedly connected to the vibrating object to transmit the vibration energy of the vibrating object to the stator; The mover can reciprocate relative to the stator along the vibration direction of the vibrating object; A guiding mechanism, connected between the stator and the mover, is used to transfer the vibration energy transmitted to the stator to the mover, so as to drive the mover to reciprocate along the vibration direction of the vibrating object; A triboelectric power generation unit is disposed between the stator and the rotor, and is used to convert the mechanical energy generated when the rotor reciprocates relative to the stator along the vibration direction of the vibrating object into a first electrical signal, thereby forming the first electrical energy output to the outside. A friction sensing unit is disposed between the stator and the mover, and is used to convert the mechanical energy generated when the mover reciprocates relative to the stator along the vibration direction of the vibrating object into a second electrical signal; and A signal processing unit is used to process the second electrical signal to obtain the vibration frequency of the vibrating object. The stator includes a stator base plate, a stator top plate, and several stator partitions arranged in parallel and spaced layers, as well as a stator side plate connecting the stator base plate, the stator top plate, and all stator partitions into a whole. During the movement of the stator with the vibrating object, the stator base plate, stator side plate, stator top plate, and all stator partitions remain relatively stationary. The mover includes a mover base plate, mover top plate, and several mover partitions arranged in parallel and spaced layers, as well as a mover side plate connecting the mover base plate, the mover top plate, and all mover partitions into a whole. During the reciprocating motion of the mover relative to the stator along the vibration direction of the vibrating object, the mover base plate, mover side plate, mover top plate, and all mover partitions remain relatively stationary. Except for the side plate, the remaining plates in the stator and the mover are arranged in parallel and staggered order to form an interdigitated shape.

2. The vibration energy harvesting and self-powered vibration monitoring device according to claim 1, characterized in that, The guiding mechanism includes springs, guide rods, linear bearings, spring flanges, and linear bearing flanges. The guide rods are distributed at each corner of the stator and the mover. The bottom end of each guide rod is fixedly connected to the stator base plate, and the top end of each guide rod is fixedly connected to the inner hole of a corresponding spring flange. The bottom of each spring flange is fixedly connected to the top end of a corresponding spring, and the top end of each spring flange is fixedly connected to the bottom end of the mover top plate. Each corner of the top end of the mover top plate is fixedly connected to a linear bearing flange, and each linear bearing is fixed in the inner hole of a corresponding linear bearing flange. The outer diameter of the linear bearing matches the inner diameter of the linear bearing flange. Each spring is sleeved on the outside of a corresponding guide rod, and the bottom end of each spring is fixedly connected to the stator base plate.

3. The vibration energy harvesting and self-powered vibration monitoring device according to claim 1, characterized in that, The triboelectric power generation unit is a contact-separated type, disposed between the stator partition and the rotor partition on opposite sides. It includes a first elastic layer, a first electrode layer, and a first friction layer fixedly disposed on the rotor partition facing the stator partition and stacked sequentially, and a second elastic layer, a second electrode layer, and a second friction layer fixedly disposed on the stator partition facing the rotor partition and stacked sequentially. The first elastic layer is disposed closer to the rotor partition than the first friction layer, and the second elastic layer is disposed closer to the stator partition than the second friction layer. The first friction layer and the second friction layer are made of materials with different electron gain and loss capabilities. During the reciprocating motion of the rotor relative to the stator along the vibration direction, the first electrical signal is generated between the first electrode layer and the second electrode layer.

4. The vibration energy harvesting and self-powered vibration monitoring device according to claim 1, characterized in that, The friction sensing unit is disposed between the stator top plate and the mover top plate on opposite sides, and includes a third elastic layer and a third electrode layer fixedly disposed on the mover top plate facing the stator top plate and stacked thereon, and a fourth elastic layer, a fourth electrode layer and a third friction layer fixedly disposed on the stator top plate facing the mover top plate and stacked thereon in sequence. The third elastic layer is disposed closer to the mover top plate than the third electrode layer, and the fourth elastic layer is disposed closer to the stator top plate than the third friction layer. The third friction layer is made of a material with a different electron gain and loss capability than the third electrode layer. During the reciprocating motion of the mover relative to the stator along the vibration direction, the second electrical signal generated between the third electrode layer and the fourth electrode layer is acquired by a data acquisition card.

5. The vibration energy harvesting and self-powered vibration monitoring device according to claim 1, characterized in that, The signal processing unit performs signal processing on the second electrical signal, including filtering and Fourier transforming the second electrical signal.

6. The vibration energy harvesting and self-powered vibration monitoring device according to any one of claims 2 to 5, characterized in that, It also includes an electromagnetic power generation unit disposed between the stator and the mover, which converts the mechanical energy generated when the mover reciprocates relative to the stator along the vibration direction of the vibrating object into a third electrical signal, thereby forming a second electrical energy output to the outside.

7. The vibration energy harvesting and self-powered vibration monitoring device according to claim 6, characterized in that, An electromagnetic power generation unit is provided between the stator base plate and the moving base plate on opposite sides, and / or between the stator top plate and the moving top plate on opposite sides; Each electromagnetic power generation unit includes an induction coil and a magnet. During the reciprocating motion of the mover relative to the stator along the vibration direction, the distance between the magnet and the induction coil periodically increases or decreases.

8. The vibration energy harvesting and self-powered vibration monitoring device according to claim 7, characterized in that, Each set of electromagnetic power generation units is provided with multiple corresponding induction coils and magnets.

9. The vibration energy harvesting and self-powered vibration monitoring device according to claim 6, characterized in that, It also includes an improved step-down circuit, which comprises a rectifier bridge, a gas discharge tube, a diode, and an LC oscillation circuit. The AC terminal of the rectifier bridge is connected to the output terminals of the triboelectric generator and the electromagnetic generator. The positive terminal of the rectifier bridge is connected to one end of the gas discharge tube. The positive terminal of the diode and one end of the inductor in the LC oscillation circuit are connected to the other end of the gas discharge tube. The other end of the inductor is connected to the positive terminal of the capacitor in the LC oscillation circuit. The negative terminal of the capacitor and the positive terminal of the diode are connected to the negative terminal of the rectifier bridge. The capacitor is connected to the load.

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