Self-powered three-degree-of-freedom absolute vibration sensor

Abstract

The invention relates to the technical field of vibration sensing, in particular to a self-powered three-degree-of-freedom absolute vibration sensor. The device comprises a hanging block, a connecting rod mechanism is assembled on the outer side of the hanging block, the connecting rod mechanism comprises an X-shaped rod set, supporting columns, a buckling beam, a piezoelectric ceramic piece, a detachable damper, a bottom ring, a top ring and a power management circuit, and the three supporting columns are evenly distributed and fixed to the bottom of the hanging block. According to the invention, the suspension block can obtain an extremely low resonant frequency in the horizontal direction through the well designed connecting rod mechanism, the extremely low resonant frequency in the vertical direction is realized through the X rod group, the combination of the two can realize the capture of ultra-low frequency vibration in a three-dimensional space, and the sensitivity is high. And meanwhile, mechanical energy generated by vibration can be converted into electric energy through the piezoelectric buckling beam, and the relative displacement measurer is driven to work, so that self-powered measurement is achieved, use is more environmentally friendly and convenient, the overall structure is compact, transportation is more convenient, and practicability is high.

Description

Technical Field

[0001] The invention relates to the field of vibration sensing technology, and in particular to a self-powered three-degree-of-freedom absolute vibration sensor. Background Art

[0002] Vibration is a common natural phenomenon in nature. There is a wide range of demands for multi-degree-of-freedom low-frequency vibration sensing in the fields of health monitoring of large bridges, high-rise buildings, coal fields, nuclear power plants, mountains, dams, large rotating machinery, and offshore platforms, measurement of wind and waves, earth pulsation, and geological exploration. In such scenarios, there are often many low-frequency and ultra-low-frequency signals, and acceleration signals are easily "drowned" in noise. Vibration can only be better described by using displacement sensors. In such scenarios, it is often difficult to find an absolutely stationary reference point, and it is difficult to apply various mature relative motion measurement elements such as laser displacement sensors and Hall displacement sensors. Absolute vibration sensing technology is often required to better describe the measured vibration. The working environment is harsh, the cable power supply distance is long, and it is inconvenient to replace the battery. Therefore, self-powered vibration sensing technology is required.

[0003] Based on this, another technical solution is proposed to solve the above problems, which is urgently needed in the current field. For this purpose, we propose a self-powered three-degree-of-freedom absolute vibration sensor. Summary of the invention

[0004] The object of the present invention is to provide a self-powered three-degree-of-freedom absolute vibration sensor to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A self-powered three-degree-of-freedom absolute vibration sensor, comprising a suspension block, the outer side of the suspension block is equipped with a connecting rod mechanism, the connecting rod mechanism comprises an X-shaped rod group, a support column, a buckling beam, a piezoelectric ceramic sheet, a detachable damper, a bottom ring, a top ring and a power management circuit, three support columns are evenly fixed at the bottom of the suspension block, a bottom ring is fixed at the bottom of the three support columns, and three groups of X-shaped rod groups are evenly connected to the top of the bottom ring through a universal ball, and the X-shaped rod group comprises a plurality of groups of X-shaped rods, and each layer consists of two X-shaped rods and a joint;

[0007] Buckling beams are installed on the X-shaped rod groups, both ends of the buckling beams are connected to the ends of the X-shaped rods, piezoelectric ceramic sheets are pasted on the upper surfaces of the buckling beams, and the buckling beams and the piezoelectric ceramic sheets constitute a piezoelectric buckling beam;

[0008] A detachable damper is installed between the two joints of the X-shaped rod, the tops of the three groups of X-shaped rods are connected to a top ring through a universal ball, and the inner hollow positions of the X-shaped rods and the inner hollow positions of the top rings are equipped with power management circuits.

[0009] Preferably, one end of the power management circuit is connected to the piezoelectric buckling beam, and the other end of the power management circuit is connected to a relative displacement sensor and a wireless communication device.

[0010] Preferably, the three groups of X-shaped rods are distributed symmetrically around the coaxial line of the top ring and the bottom ring.

[0011] Preferably, the piezoelectric buckling beam is perpendicular to the X-shaped rod group.

[0012] Preferably, a measuring rod is installed above the top ring, and the hanging block and the measuring rod are respectively connected to two ends of the relative displacement sensor.

[0013] Preferably, the hanging block is located on the axis connecting the centers of the top ring and the bottom ring.

[0014] It can be seen without a doubt that the above-mentioned technical solution of the present application can definitely solve the technical problem to be solved by the present application.

[0015] At the same time, through the above technical solutions, the present invention has at least the following beneficial effects:

[0016] The present invention can make the suspended object obtain an extremely low resonance frequency in the horizontal direction through a well-designed connecting rod mechanism, and realize an extremely low resonance frequency in the vertical direction through the X-rod group. The combination of the two can realize the capture of ultra-low frequency vibration in three-dimensional space with high sensitivity. At the same time, the piezoelectric buckling beam can convert the mechanical energy generated by the vibration into electrical energy and drive the relative displacement meter to work, thereby realizing self-powered measurement. It is more environmentally friendly and convenient in use, making the overall structure compact and making transportation more convenient and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0018] Figure 1 It is a schematic diagram of the 3D cable suspension structure of the present invention;

[0019] Figure 2 It is a schematic diagram of the structure of the SLS lever assembly of the present invention;

[0020] Figure 3It is a connection diagram of the power management circuit of the present invention;

[0021] Figure 4 It is a schematic diagram of the structure of the self-powered low-frequency absolute vibration sensor of the present invention;

[0022] Figure 5 It is a schematic diagram of the X-rod group structure of the present invention;

[0023] Figure 6 It is a schematic diagram of measuring bridge vibration of the present invention;

[0024] Figure 7 It is a schematic diagram of the dynamic measurement performance of the present invention.

[0025] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0026] In the figure: 1. wireless communication device; 2. hanging block; 3. X-shaped rod; 4. support column; 5. buckling beam; 6. piezoelectric ceramic plate; 7. removable damping; 8. universal ball; 9. bottom ring; 10. joint; 11. top ring; 12. measuring rod; 13. relative displacement sensor. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] Example 1

[0029] Reference Figure 1-7 A self-powered three-degree-of-freedom absolute vibration sensor comprises a hanging block 2, the outer side of the hanging block 2 is equipped with a connecting rod mechanism, the connecting rod mechanism comprises an X-shaped rod group, a support column 4, a buckling beam 5, a piezoelectric ceramic sheet 6, a detachable damper 7, a bottom ring 9, a top ring 11 and a power management circuit, three support columns 4 are evenly fixed at the bottom of the hanging block 2, the support columns 4 hardly produce displacement under the action of the whole structure, at this time the relative displacement produced at both ends of the relative displacement sensor 13 is the absolute displacement of the vibration of the measured object; a bottom ring 9 is fixed at the bottom of the three support columns 4, the top of the bottom ring 9 is evenly connected with three groups of X-shaped rod groups through a universal ball 8, the X-shaped rod group comprises a plurality of groups of X-shaped rods 3, each layer consists of two X-shaped rods 3 and a joint 10; the top ring 11 and the bottom ring 9 are parallel and coaxial;

[0030] Buckling beams 5 are installed on the X-shaped rod groups, both ends of the buckling beams 5 are connected to the ends of the X-shaped rods 3, and piezoelectric ceramic sheets 6 are pasted on the upper surfaces of the buckling beams 5. The buckling beams 5 and the piezoelectric ceramic sheets 6 form a piezoelectric buckling beam; the detachable damper 7 can adjust the damping size as needed to control the response speed and stability of the vibration system, further improving the accuracy and reliability of the measurement;

[0031] A detachable damper 7 is installed between the two joints 10 of the X-shaped rod 3. The tops of the three groups of X-shaped rods are connected to a top ring 11 through a universal ball 8. The power management circuit is placed in the inner hollow position of the X-shaped rod 3 and the inner hollow position of the top ring 11. The wires are located inside the X-shaped rod 3 and the top ring 11 for connecting the circuit; the universal ball 8 is used to connect the X-rod group with the bottom ring 9 and the top ring 11, so that the X-shaped rod 3 can swing freely when vibrated.

[0032] The three groups of X-shaped rods are centrally symmetrically distributed around the coaxial line of the top ring 11 and the bottom ring 9. The X-shaped rods can enable the suspended block 2 to obtain an extremely low resonance frequency in the vertical direction, so as to capture ultra-low frequency vibrations in the vertical direction.

[0033] The piezoelectric buckling beam is perpendicular to the X-shaped rod group. When vibration occurs, the buckling beam 5 will produce a small deformation. The piezoelectric ceramic sheet 6 attached to the surface of the buckling beam 5 will induce alternating charges under the action of vibration.

[0034] The suspended object block 2 is located on the axis connecting the center of the top ring 11 and the bottom ring 9. The suspended object block 2 is installed above the support column 4 and has an extremely low resonance frequency in three-dimensional space.

[0035] Example 2

[0036] Embodiment 1 is further optimized, specifically, as Figure 3As shown, one end of the power management circuit is connected to the piezoelectric buckling beam, and the other end of the power management circuit is connected to the relative displacement sensor 13 and the wireless communication device 1; a measuring rod 12 is installed above the top ring 11, and the hanging block 2 and the measuring rod 12 are respectively connected to the two ends of the relative displacement sensor 13. The power management circuit consists of five parts: a synchronous switching capacitor circuit SSHC (blue frame), a cascade buck-boost circuit (purple frame), an oscillator circuit (yellow frame), a wake-up circuit (green frame) and an overvoltage protection circuit (red frame). The SSHC circuit realizes the rapid reversal of the voltage at both ends through the charge transfer between the internal capacitor and the external capacitor of the piezoelectric buckling beam, and its electric energy comes from the three groups of piezoelectric buckling beams during the vibration process of the sensing system. The cascade buck-boost circuit is used for DC-DC conversion. The oscillator circuit generates a duty cycle signal to control the switch of the cascade buck-boost circuit. The wake-up circuit reduces the energy loss during the operation of the system. The overvoltage protection circuit can prevent the output voltage from being too large and ensure that the output of the power management circuit is a stable DC voltage. The power management circuit can convert unstable AC voltage into stable DC voltage, directly powering electronic devices such as the relative displacement sensor 13 and the wireless communication device 1, thereby achieving self-powering of the overall structure.

[0037] From the above, we can know that:

[0038] The present invention is directed to the following technical problems: Vibration is a common natural phenomenon in nature. There is a widespread demand for multi-degree-of-freedom low-frequency vibration sensing in the fields of health monitoring of large bridges, high-rise buildings, coal fields, nuclear power plants, mountains, dams, large rotating machinery, and offshore platforms, measurement of wind and waves, earth pulsation, and geological exploration. In such scenarios, there are often many low-frequency and ultra-low-frequency signals, and acceleration signals are easily "drowned" in noise. Vibration can only be better described by using displacement sensors; it is often difficult to find an absolutely stationary reference point in such scenarios, and it is difficult to apply various mature relative motion measurement elements such as laser displacement sensors and Hall displacement sensors. Absolute vibration sensing technology is often required to better describe the measured vibration; the working environment is harsh, the cable power supply distance is long, and it is inconvenient to replace the battery; by adopting the technical solutions of the above embodiments and the above settings, this application will inevitably solve the above technical problems and achieve the following technical effects:

[0039] The present invention can make the suspended object obtain an extremely low resonance frequency in the horizontal direction through a well-designed connecting rod mechanism, and realize an extremely low resonance frequency in the vertical direction through the X-rod group. The combination of the two can realize the capture of ultra-low frequency vibration in three-dimensional space with high sensitivity. At the same time, the piezoelectric buckling beam can convert the mechanical energy generated by the vibration into electrical energy and drive the relative displacement meter to work, thereby realizing self-powered measurement. It is more environmentally friendly and convenient in use, making the overall structure compact and making transportation more convenient and practical.

[0040] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] Obviously, the embodiments described above are only some embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are given in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific embodiments, or to perform equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of the present invention, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. A self-powered three-degree-of-freedom absolute vibration sensor, characterized in that: The invention comprises a suspension block (2), wherein the outer side of the suspension block (2) is equipped with a connecting rod mechanism, wherein the connecting rod mechanism comprises an X-shaped rod group, a support column (4), a buckling beam (5), a piezoelectric ceramic sheet (6), a detachable damper (7), a bottom ring (9), a top ring (11) and a power management circuit, wherein three support columns (4) are evenly fixed at the bottom of the suspension block (2), a bottom ring (9) is fixed at the bottom of the three support columns (4), and the top of the bottom ring (9) is evenly connected with three groups of X-shaped rod groups via a universal ball (8), wherein the X-shaped rod group comprises a plurality of groups of X-shaped rods (3), wherein each layer is composed of two X-shaped rods (3) and a joint (10); Buckling beams (5) are installed on the X-shaped rod groups, both ends of the buckling beams (5) are connected to the ends of the X-shaped rods (3), and piezoelectric ceramic sheets (6) are attached to the upper surfaces of the buckling beams (5). The buckling beams (5) and the piezoelectric ceramic sheets (6) form a piezoelectric buckling beam; A detachable damper (7) is installed between the two joints (10) of the X-shaped rod (3); the tops of the three groups of X-shaped rods are connected to a top ring (11) via a universal ball (8); and a power management circuit is placed in the inner hollow position of the X-shaped rod (3) and the inner hollow position of the top ring (11).

2. A self-powered three-degree-of-freedom absolute vibration sensor according to claim 1, characterized in that: One end of the power management circuit is connected to the piezoelectric buckling beam, and the other end of the power management circuit is connected to a relative displacement sensor (13) and a wireless communication device (1).

3. A self-powered three-degree-of-freedom absolute vibration sensor according to claim 1, characterized in that: The three groups of X-shaped rods are distributed in a centrally symmetrical manner around the coaxial line of the top ring (11) and the bottom ring (9).

4. A self-powered three-degree-of-freedom absolute vibration sensor according to claim 3, characterized in that: The piezoelectric buckling beam is perpendicular to the X-bar group.

5. The self-powered three-degree-of-freedom absolute vibration sensor according to claim 2, characterized in that: A measuring rod (12) is installed above the top ring (11), and the hanging block (2) and the measuring rod (12) are respectively connected to two ends of a relative displacement sensor (13).

6. The self-powered three-degree-of-freedom absolute vibration sensor according to claim 1, characterized in that: The hanging block (2) is located on the axis connecting the center of the top ring (11) and the bottom ring (9).

Images