Hydrophone demodulation interferometer with load flexibility adjustment vibration isolation

Abstract

The present application relates to hydrophone demodulation technical field, disclose a kind of hydrophone demodulation interferometer with load flexible adjustment vibration isolation technology, comprising: interferometer module, shell and low-frequency vibration isolator, interferometer module is encapsulated in shell, the bottom of shell is fixedly connected with the top of low-frequency vibration isolator;Low-frequency vibration isolator includes base platform, two vibration isolation units, horizontal guide rod, load platform, two torsional magnetic negative stiffness mechanisms and two telescopic hinge structures;Two vibration isolation units are symmetrically arranged on the two sides of base platform, etc.;The hydrophone demodulation interferometer with load flexible adjustment vibration isolation technology can make low-frequency vibration isolator present quasi-zero stiffness and load flexible adjustable characteristics by configuring appropriate structural parameters and adjusting the pre-tightening force of vertical spring and the angle between connecting rod and horizontal direction of vertical fixing ring and horizontal fixing ring, so as to realize the effective isolation between hydrophone demodulation interferometer and environmental noise.

Description

Technical Field

[0001] This invention relates to the field of hydrophone demodulation technology, specifically to a hydrophone demodulation interferometer with load flexible adjustment vibration isolation technology. Background Technology

[0002] Hydrophones, also known as underwater acoustic transducers, are used to receive acoustic signals in water and are important devices in marine underwater communication. Fiber Bragg grating hydrophones are sensors that use fiber optic gratings to sense underwater sound waves. During signal demodulation in fiber Bragg grating hydrophones, a demodulation interferometer is required. Environmental noise received by the hydrophone demodulation interferometer can distort the interferometer's waveform, leading to signal distortion and reduced accuracy. To remove noise received by the hydrophone demodulation interferometer, it is necessary to encapsulate the interferometer and install vibration isolators. These isolators absorb and dissipate the vibration energy of environmental noise, thus achieving noise removal. However, in existing technologies, the linear vibration isolation system of the hydrophone demodulation interferometer is constrained by the positive correlation between natural frequency and stiffness. To achieve low-frequency vibration isolation, the system design is forced to reduce stiffness, resulting in weakened load-bearing capacity. This characteristic causes the vibration isolation effect of the linear system to deteriorate drastically in the low-frequency range. The innovative development of nonlinear dynamics theory has provided a new solution to this technical challenge. By introducing innovative mechanisms such as quasi-zero stiffness, the vibration isolation system of a hydrophone demodulation interferometer can achieve dynamic low stiffness while maintaining high static stiffness. However, the existing quasi-zero stiffness vibration reduction system of a hydrophone demodulation interferometer has poor adaptability to large-amplitude vibrations or impact loads, and it is necessary to combine it with other technologies to expand the operating bandwidth. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a hydrophone demodulation interferometer with load-flexible vibration isolation technology, which can effectively isolate the hydrophone demodulation interferometer from environmental noise.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A hydrophone demodulation interferometer with load-flexible vibration isolation technology includes: an interferometer module, a housing, and a low-frequency vibration isolator. The interferometer module is encapsulated within the housing, and the bottom of the housing is fixedly connected to the top of the low-frequency vibration isolator. The low-frequency vibration isolator includes a base platform, two vibration isolation units, a horizontal guide rod, a load platform, two torsional magnetic negative stiffness mechanisms, and two telescopic hinge structures. The two vibration isolation units are symmetrically arranged on both sides of the base platform. Each vibration isolation unit includes a vertical guide rod, a vertical fixing ring, a vertical spring, and a vertical slip ring. The vertical guide rod is fixed to the side of the base platform, the vertical fixing ring is sleeved on the bottom of the vertical guide rod, the vertical spring is sleeved on the vertical guide rod and located above the vertical fixing ring, and the vertical slip ring is sleeved on the vertical guide rod. The load platform has two ends. A circular hole is provided, which is respectively fitted onto two vertical guide rods. The load platform contacts the tops of the two vertical slip rings, compressing two vertical springs. A horizontal guide rod is fixed between the two vertical guide rods and located between the load platform and the base platform. A horizontal slip ring is fitted at each end of the horizontal guide rod. Each horizontal slip ring is connected to the outer shell of a torsional magnetic negative stiffness mechanism. Both horizontal slip rings can be fixed at any position on the horizontal guide rod. The two torsional magnetic negative stiffness mechanisms have the same structure, both including a rotating shaft. The structure of the torsional magnetic negative stiffness mechanism can generate a magnetic force that opposes the rotation of the rotating shaft. The lengths of the two telescopic hinge structures can be extended or retracted. One end of the telescopic hinge structure is hinged to a vertical slip ring, and the other end is connected to the rotating shaft of a torsional magnetic negative stiffness mechanism.

[0006] In this invention, preferably, the torsional magnetic negative stiffness mechanism further includes a housing, a first bearing, a second bearing, an inner magnet, and an outer magnet. The housing has a groove inside, and the outer magnet is tile-shaped. The outer magnet is evenly distributed along the circumference and fixed in the groove of the housing. The rotating shaft is placed inside the housing, and the two ends of the rotating shaft are connected to the two ends of the housing through the first bearing and the second bearing. The inner magnet is fixed to the surface of the rotating shaft. The outer magnet and the inner magnet are radially magnetized, and the magnetic force directions corresponding to the outer magnet and the inner magnet are consistent, forming a repulsive magnetic field.

[0007] In this invention, preferably, the two vibration isolation units are a first vibration isolation unit and a second vibration isolation unit. The first vibration isolation unit includes a first vertical guide rod, a first vertical fixing ring, a first vertical spring, and a first vertical slip ring. The first vertical guide rod is fixed to the side of the foundation platform. The first vertical fixing ring is sleeved on the bottom of the first vertical guide rod. The first vertical spring is sleeved on the first vertical guide rod and located above the first vertical fixing ring. The first vertical slip ring is sleeved on the first vertical guide rod. The second vibration isolation unit includes a second vertical guide rod, a second vertical fixing ring, a second vertical spring, and a second vertical slip ring. The second vertical guide rod is fixed to the side of the foundation platform, the second vertical fixing ring is sleeved on the bottom of the second vertical guide rod, the second vertical spring is sleeved on the second vertical guide rod and located above the second vertical fixing ring, and the second vertical sliding ring is sleeved on the second vertical guide rod; the first vibration isolation unit also includes a first positioning bushing, which is fixed to the upper surface of the foundation platform by bolts, and the first vertical guide rod is inserted into the first positioning bushing; the second vibration isolation unit also includes a second positioning bushing, which is fixed to the upper surface of the foundation platform by bolts, and the second vertical guide rod is inserted into the second positioning bushing.

[0008] In this invention, preferably, the first vibration isolation unit further includes a first mounting base, which is L-shaped, with its base plate fixed to the foundation platform and a horizontal through hole on its side plate, through which a horizontal guide rod passes. The second vibration isolation unit further includes a second mounting base, which is L-shaped, with its base plate fixed to the foundation platform and a horizontal through hole on its side plate, through which a horizontal guide rod passes.

[0009] In this invention, preferably, the two telescopic hinge structures are a first telescopic hinge structure and a second telescopic hinge structure, and the two torsional magnetic negative stiffness mechanisms are a first torsional magnetic negative stiffness mechanism and a second torsional magnetic negative stiffness mechanism. The first telescopic hinge structure includes a first telescopic link and a second telescopic link, both of which are hinged at one end to the semi-circular rectangular connecting head of the first vertical slip ring, and at the other end to the rotating shaft of the first torsional magnetic negative stiffness mechanism. The second telescopic hinge structure includes a third telescopic link and a fourth telescopic link, both of which are hinged at one end to the semi-circular rectangular connecting head of the second vertical slip ring, and at the other end to the rotating shaft of the second torsional magnetic negative stiffness mechanism.

[0010] In this invention, preferably, the first telescopic link and the second telescopic link are respectively connected to the rotating shaft of the first torsional magnetic negative stiffness mechanism via a flat key, and the third telescopic link and the fourth telescopic link are respectively connected to the rotating shaft of the second torsional magnetic negative stiffness mechanism via a flat key.

[0011] In this invention, preferably, the low-frequency vibration isolator further includes a first horizontal fixing ring, a second horizontal fixing ring, a third horizontal fixing ring, and a fourth horizontal fixing ring, with the two horizontal slip rings being the first horizontal slip ring and the second horizontal slip ring, the first horizontal fixing ring and the second horizontal fixing ring being fixed to both ends of the first horizontal slip ring, and the third horizontal fixing ring and the fourth horizontal fixing ring being fixed to both ends of the second horizontal slip ring.

[0012] In this invention, preferably, both the first vertical fixing ring and the second vertical fixing ring are fixed by locking bolts.

[0013] In this invention, preferably, the first horizontal fixing ring and the second horizontal fixing ring are fixed to both ends of the first horizontal slip ring by locking bolts, and the third horizontal fixing ring and the fourth horizontal fixing ring are fixed to both ends of the second horizontal slip ring by locking bolts.

[0014] In this invention, preferably, the base platform is a rectangular plate structure.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] This invention relates to a hydrophone demodulation interferometer with load-flexible vibration isolation technology. By configuring appropriate structural parameters and adjusting the preload of the vertical spring and the angle between the telescopic link and the horizontal direction of the vertical and horizontal fixed rings, the low-frequency vibration isolator can exhibit quasi-zero stiffness and load-flexible adjustable characteristics, thereby achieving effective isolation between the hydrophone demodulation interferometer and environmental noise. The adjustable design of the horizontal and vertical fixed rings, through adjusting the preload of the vertical spring and the angle between the telescopic link and the horizontal direction, allows the low-frequency vibration isolator to adapt to different load conditions, achieving load-flexible adjustment capability. Without changing other parameters, the excellent vibration isolation effect of the hydrophone demodulation interferometer can be achieved. The torsional magnetic negative stiffness mechanism generates torsional negative stiffness and provides vertical negative stiffness to the system under angular position transformation, realizing quasi-zero stiffness characteristics, effectively reducing the resonance frequency of the system in low-frequency environment and improving the vibration isolation performance of the hydrophone demodulation interferometer. By changing the parameters of the torsional magnetic negative stiffness mechanism, the stiffness nonlinearity near the quasi-zero stiffness point and the overall stiffness of the low-frequency vibration isolator can be adjusted. The integrated design of the hydrophone demodulation interferometer and the load flexible adjustment vibration isolation technology can greatly reduce the overall volume and save installation space. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a hydrophone demodulation interferometer with load flexible adjustment vibration isolation technology according to an embodiment of the present invention;

[0018] Figure 2This is a schematic diagram of the interferometer module and housing according to an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the structure of a low-frequency vibration isolator according to an embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the first vibration isolation unit structure according to an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the second vibration isolation unit structure according to an embodiment of the present invention;

[0022] Figure 6 This is a partial axial cross-sectional view of the first torsional magnetic negative stiffness mechanism and the second torsional magnetic negative stiffness mechanism according to an embodiment of the present invention.

[0023] Figure 7 This is a radial cross-sectional view of the first torsional magnetic negative stiffness mechanism and the second torsional magnetic negative stiffness mechanism according to an embodiment of the present invention.

[0024] Figure 8 This is an equivalent schematic diagram of a low-frequency vibration isolator according to an embodiment of the present invention;

[0025] Figure 9 This is a comparison of the transmissivity curves of a traditional linear vibration damper and the low-frequency vibration isolator of this invention.

[0026] Explanation of reference numerals in the attached drawings: 1. Foundation platform; 2. First vibration isolation unit; 201. First vertical guide rod; 202a. First telescopic connecting rod; 202b. Second telescopic connecting rod; 203a. First horizontal fixing ring; 203b. Second horizontal fixing ring; 204. First horizontal slip ring; 205. First vertical slip ring; 206. First mounting base; 206a. First mounting base side plate; 206b. First mounting base bottom plate; 207. First vertical fixing ring; 208. First vertical spring; 209. First positioning bushing; 3. Horizontal guide rod; 4. Second vibration isolation unit; 401. Second vertical guide rod; 402a. Third telescopic connecting rod; 402b. Fourth telescopic connecting rod; 403a. Third horizontal guide rod; 402a. 403b, Fourth horizontal fixed ring; 404, Second horizontal slip ring; 405, Second vertical slip ring; 406, Second mounting base; 406a, Second mounting base side plate; 406b, Second mounting base bottom plate; 407, Second vertical fixed ring; 408, Second vertical spring; 409, Second positioning bushing; 5, Load platform; 6a, First torsional magnetic negative stiffness mechanism; 6b, Second torsional magnetic negative stiffness mechanism; 601, Housing; 602a, First bearing; 602b, Second bearing; 603a, First flat key; 603b, Second flat key; 604, Rotating shaft; 605, Inner magnet; 606, Outer magnet; 7, Interferometer module; 8, Housing; 9, Low-frequency vibration isolator. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] Please also see Figures 1 to 7 A preferred embodiment of the present invention provides a hydrophone demodulation interferometer with load-flexible vibration isolation technology, comprising an interferometer module 7, a housing 8, and a low-frequency vibration isolator 9. The interferometer module 7 is used to demodulate the signal of the hydrophone. The interferometer module 7 is encapsulated in the housing 8, and the bottom of the housing 8 is fixedly connected to the top of the low-frequency vibration isolator 9. The low-frequency vibration isolator 9 includes a base platform 1, two vibration isolation units (first vibration isolation unit 2 and second vibration isolation unit 4), a horizontal guide rod 3, a load platform 5, two torsional magnetic negative stiffness mechanisms (first torsional magnetic negative stiffness mechanism 6a and second torsional magnetic negative stiffness mechanism 6b), and two telescopic hinge structures (first telescopic hinge structure and second telescopic hinge structure). The base platform 1 serves as the support base of the vibration isolator. The first vibration isolation unit 2 and the second vibration isolation unit 4 are symmetrically arranged on both sides of the base platform 1. The load platform 5 is connected to the vibration isolation units through a vertical guide rod and is used to bear external loads.

[0031] The vibration isolation unit includes a vertical guide rod, a vertical fixing ring, a vertical spring, and a vertical slip ring. The vertical guide rod is fixed to the side of the foundation platform, the vertical fixing ring is sleeved on the bottom of the vertical guide rod, the vertical spring is sleeved on the vertical guide rod and located above the vertical fixing ring, and the vertical slip ring is sleeved on the vertical guide rod.

[0032] Specifically, the first vibration isolation unit 2 includes a first vertical guide rod 201, a first vertical fixing ring 207, a first vertical spring 208, and a first vertical slip ring 205. The first vertical guide rod 201 is fixed to the side of the foundation platform 1. The first vertical fixing ring 207 is sleeved on the bottom of the first vertical guide rod 201. The first vertical spring 208 is sleeved on the first vertical guide rod 201 and located above the first vertical fixing ring 207. The first vertical slip ring 205 is sleeved on the first vertical guide rod 201.

[0033] The second vibration isolation unit 4 includes a second vertical guide rod 401, a second vertical fixing ring 407, a second vertical spring 408, and a second vertical slip ring 405. The second vertical guide rod 401 is fixed to the side of the foundation platform 1. The second vertical fixing ring 407 is sleeved on the bottom of the second vertical guide rod 401. The second vertical spring 408 is sleeved on the second vertical guide rod 401 and located above the second vertical fixing ring 407. The second vertical slip ring 405 is sleeved on the second vertical guide rod 401.

[0034] The load platform 5 is horizontally positioned directly above the base platform 1, with round holes at its left and right ends, which are respectively fitted onto the first vertical guide rod 201 and the second vertical guide rod 401. The bottom of the load platform 5 has a hollow cylindrical structure that contacts the top ends of the first vertical slip ring 206 and the second vertical slip ring 406, pressing the first vertical spring 208 and the second vertical spring 408, thereby transferring the load to the vertical spring assembly.

[0035] The horizontal guide rod 3 is fixed between the first vertical guide rod 201 and the second vertical guide rod 401, and is located between the load platform 5 and the foundation platform 1. The two ends of the horizontal guide rod 3 are respectively fitted with a first horizontal slip ring 204 and a second horizontal slip ring 404. The first horizontal slip ring 204 is connected to the outer shell of the first torsional magnetic negative stiffness mechanism 6a, and the second horizontal slip ring 404 is connected to the outer shell of the second torsional magnetic negative stiffness mechanism 6b. Both the first horizontal slip ring 204 and the second horizontal slip ring 404 can be fixed at any position on the horizontal guide rod 3.

[0036] The first torsional magnetic negative stiffness mechanism 6a and the second torsional magnetic negative stiffness mechanism 6b have the same structure, both including a rotating shaft 604. The structure of the first torsional magnetic negative stiffness mechanism 6a and the second torsional magnetic negative stiffness mechanism 6b can generate a magnetic force that hinders the rotation of the rotating shaft 604.

[0037] The lengths of both the first and second telescopic hinge structures are extendable. One end of the first telescopic hinge structure is hinged to the first vertical slip ring 205, and the other end is connected to the rotating shaft 604 of the first torsional magnetic negative stiffness mechanism 6a. One end of the second telescopic hinge structure is hinged to the second vertical slip ring 405, and the other end is connected to the rotating shaft 604 of the second torsional magnetic negative stiffness mechanism 6b.

[0038] Preferably, the structures of the first torsional magnetic negative stiffness mechanism 6a and the second torsional magnetic negative stiffness mechanism 6b are as follows: Figure 6 and Figure 7 As shown, the outer casing 601 has a groove inside. The outer magnets 606 are tile-shaped and are evenly distributed and fixed in the grooves of the outer casing 601 along the circumference. The rotating shaft 604 is placed inside the outer casing 601. The two ends of the rotating shaft 604 are connected to the two ends of the outer casing 601 through the first bearing 602a and the second bearing 602b to realize the positioning and rotation of the rotating shaft 604. The outer circumference of the rotating shaft 604 has a groove, and the inner magnet 605 is fixed in the groove of the rotating shaft 604. The outer magnets 606 and the inner magnets 605 are radially magnetized, and the outer magnets 606 and the inner magnets 605 correspond one-to-one. Furthermore, the magnetic directions of the inner and outer magnets are consistent, and their corresponding magnetic poles form a periodic repulsive magnetic field. When the rotating shaft 604 is torn by an external force, the magnetic repulsion between the inner magnet 605 and the outer magnet 606 generates a nonlinear negative stiffness effect, which cancels the positive stiffness of the vertical spring to achieve the quasi-zero stiffness characteristic of the system. By adjusting the distance between the outer magnet 606 and the inner magnet 605, the size of the magnets, and the number of magnets, the amplitude of the magnetic repulsion, the stiffness of the torsional magnetic negative stiffness mechanism, and the stiffness nonlinearity near the quasi-zero stiffness point can also be changed to optimize the low-frequency vibration isolation performance of the system.

[0039] Preferably, the first vibration isolation unit 2 and the second vibration isolation unit 4 are fixedly connected to the base platform 1 via a first positioning bushing 209, a second positioning bushing 409, a first mounting base 206, and a second mounting base 406. The first positioning bushing 209 and the second positioning bushing 409 are symmetrically installed on the left and right sides of the base platform 1. Preferably, the base platform 1 is a rectangular plate structure. The first positioning bushing 209 and the second positioning bushing 409 are fixed to the upper surface of the base platform 1 by bolts, and are used to position the first vertical guide rod 201 and the second vertical guide rod 401, respectively. The first vertical guide rod 201 is inserted into the first positioning bushing 209, and the second vertical guide rod 401 is inserted into the second positioning bushing 409; both extend vertically. A first vertical fixing ring 207 is sleeved on the bottom of the first vertical guide rod 201, and a second vertical fixing ring 407 is sleeved on the bottom of the second vertical guide rod 401, and both are fixed by locking bolts to limit the initial position of the vertical spring. A first vertical spring 208 is sleeved on a first vertical guide rod 201 and located above a first vertical fixing ring 207. A second vertical spring 408 is sleeved on a second vertical guide rod 401 and located above a second vertical fixing ring 407. A first vertical slip ring 205 is sleeved on a first vertical guide rod 201 and located above a first vertical spring 208. A second vertical slip ring 405 is sleeved on a second vertical guide rod 401 and located above a second vertical spring 408.

[0040] Preferably, the first vibration isolation unit 2 includes an L-shaped first mounting base 206, and the second vibration isolation unit 4 includes an L-shaped second mounting base 406. The first mounting base 206 and the second mounting base 406 are respectively fixed to both sides of the foundation platform 1 via the first mounting base base plate 206b and the second mounting base base plate 406b. The first mounting base side plate 206a and the second mounting base side plate 406a are provided with horizontal through holes, and the horizontal guide rod 3 passes through the through holes of the first mounting base side plate 206a and the second mounting base side plate 406a and extends in the horizontal direction.

[0041] Preferably, the first telescopic hinge structure includes a first telescopic link 202a and a second telescopic link 202b. Both the first telescopic link 202a and the second telescopic link 202b are hinged at one end to the semi-circular rectangular connector of the first vertical slip ring 205, and the other end is connected to the rotating shaft of the first torsional magnetic negative stiffness mechanism 6a.

[0042] The second telescopic hinge structure includes a third telescopic link 402a and a fourth telescopic link 402b. Both the third telescopic link 402a and the fourth telescopic link 402b are hinged at one end to the semi-circular rectangular connector of the second vertical slip ring 405, and the other end is connected to the rotating shaft of the second torsional magnetic negative stiffness mechanism 6b.

[0043] The first horizontal slip ring 204 and the second horizontal slip ring 404 are sleeved at both ends of the horizontal guide rod 3. The first horizontal slip ring 204 is connected to the outer shell of the first torsional magnetic negative stiffness mechanism 6a by locking bolts, and the second horizontal slip ring 404 is connected to the outer shell of the second torsional magnetic negative stiffness mechanism 6b by locking bolts. One end of the first telescopic link 202a and the second telescopic link 202b is fixed to the semi-circular rectangular connecting head of the first vertical slip ring 205 by bolts, and the other end is connected to the rotating shaft 604 of the torsional magnetic negative stiffness mechanism by the first flat key 603a and the second flat key 603b, respectively. The lengths of the first telescopic link 202a and the second telescopic link 202b are both telescopic. One end of the third telescopic link 402a and the fourth telescopic link 402b is fixed to the semi-circular rectangular connecting head of the second vertical slip ring 405 by bolts, and the other end is connected to the rotating shaft 604 of the torsional magnetic negative stiffness mechanism by the first flat key 603a and the second flat key 603b, respectively. Both the third telescopic link 402a and the fourth telescopic link 402b are telescopic. The first horizontal fixing ring 203a and the second horizontal fixing ring 203b are fixed to both ends of the first horizontal slip ring 204 by locking bolts. The third horizontal fixing ring 403a and the fourth horizontal fixing ring 403b are fixed to both ends of the second horizontal slip ring 404 by locking bolts. These are used to adjust the angle between the telescopic link and the horizontal direction. By changing the preload force of the vertical fixing ring on the vertical spring, the load adjustable characteristic can be achieved.

[0044] The principle of low-frequency vibration isolators is as follows:

[0045] Figure 6 This is a schematic diagram of the vibration damper of the present invention. The mass of the load platform is M, and the stiffness of the vertical spring is... The equivalent damping of the system is C. This represents the vibration displacement of the load platform. Assuming the vibration displacement of the base platform and neglecting higher-order nonlinear terms, the dynamic equation of the system is:

[0046]

[0047] In the formula , This represents the static offset of the load platform caused by gravity acting on the spring system when there is no external excitation. For the mass of the torsional magnetic negative stiffness mechanism, L is the length of the connecting rod. For resilience.

[0048] Due to the presence of nonlinear terms, the dynamic behavior of the system is approximated by the harmonic balance method. Assume the steady-state response is... Thus, the transfer rate formula is obtained:

[0049]

[0050] In the formula This is the maximum amplitude of the vibration of the base platform.

[0051] Figure 7 The figure shows a comparison of the vibration transmissivity curves of the low-frequency vibration isolator with load flexibility adjustment capability in this embodiment and the traditional linear vibration isolator. As can be seen from the figure, the traditional linear vibration isolator has a high peak value in the resonance region and its natural frequency is also relatively low. The vibration isolator proposed in this invention has vibration isolation effect in the entire frequency band and can achieve low-frequency vibration isolation.

[0052] To comprehensively evaluate the actual effect of the proposed vibration reduction and noise reduction scheme on the interferometer, the researchers placed the same interferometer in an identical background noise environment and conducted tests in two phases: In the first phase, the interferometer was neither subjected to any vibration isolation nor sound insulation treatment; in the second phase, the interferometer module was encapsulated and fitted with a low-frequency vibration isolator, while keeping all other experimental conditions completely consistent. The signals demodulated by the interferometer module using Phase Generated Carrier (PGC) in both phases were then subjected to spectral analysis.

[0053] Without any vibration isolation measures, when the optical path difference is 10m, the noise level of the interferometer module at 1kHz is −65.58dB, which is significantly high. However, after adding a low-frequency vibration isolator, the noise amplitude at the same frequency drops rapidly to −96.33dB, a reduction of more than 30dB. This result clearly demonstrates that the hydrophone demodulation interferometer with load-flexible vibration isolation technology can significantly suppress the coupling of external noise to the hydrophone demodulation interferometer, greatly improving the overall noise performance of the hydrophone demodulation interferometer and fully meeting the requirements of subsequent applications for low noise and high stability.

[0054] To comprehensively evaluate the actual effect of the proposed vibration reduction and noise reduction scheme on the interferometer, the researchers placed the same interferometer in an identical background noise environment and conducted tests in two phases: In the first phase, the interferometer was neither subjected to any vibration isolation nor sound insulation treatment; in the second phase, the interferometer module was encapsulated and fitted with a low-frequency vibration isolator, while keeping all other experimental conditions completely consistent. The signals demodulated by the interferometer module using Phase Generated Carrier (PGC) in both phases were then subjected to spectral analysis.

[0055] Without any vibration isolation measures, when the optical path difference is 10m, the noise level of the interferometer module at 1kHz is −65.58dB, which is significantly high. However, after adding a low-frequency vibration isolator, the noise amplitude at the same frequency drops rapidly to −96.33dB, a reduction of more than 30dB. This result clearly demonstrates that the hydrophone demodulation interferometer with load-flexible vibration isolation technology can significantly suppress the coupling of external noise to the hydrophone demodulation interferometer, greatly improving the overall noise performance of the hydrophone demodulation interferometer and fully meeting the requirements of subsequent applications for low noise and high stability.

[0056] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should fall within the patent scope covered by the present invention.

Claims

1. A hydrophone demodulation interferometer with load-flexible vibration isolation technology, characterized in that, include: The interferometer module, housing, and low-frequency vibration isolator are included. The interferometer module is encapsulated inside the housing, and the bottom of the housing is fixedly connected to the top of the low-frequency vibration isolator. The low-frequency vibration isolator includes a base platform, two vibration isolation units, a horizontal guide rod, a load platform, two torsional magnetic negative stiffness mechanisms, and two telescopic hinge structures. Two vibration isolation units are symmetrically arranged on both sides of the foundation platform. Each vibration isolation unit includes a vertical guide rod, a vertical fixing ring, a vertical spring, and a vertical slip ring. The vertical guide rod is fixed to the side of the foundation platform. The vertical fixing ring is sleeved on the bottom of the vertical guide rod. The vertical spring is sleeved on the vertical guide rod and located above the vertical fixing ring. The vertical slip ring is sleeved on the vertical guide rod. The load platform has round holes at both ends, which are respectively fitted onto two vertical guide rods. The load platform contacts the tops of two vertical slip rings and presses against two vertical springs. The horizontal guide rod is fixed between two vertical guide rods and is located between the load platform and the foundation platform. A horizontal slip ring is fitted at each end of the horizontal guide rod. Each horizontal slip ring is connected to the outer shell of a torsional magnetic negative stiffness mechanism. Both horizontal slip rings can be fixed at any position on the horizontal guide rod. The two torsional magnetic negative stiffness mechanisms have the same structure, both including a rotating shaft, and the structure of the torsional magnetic negative stiffness mechanism can generate a magnetic force that opposes the rotation of the rotating shaft; Both telescopic hinge structures are telescopic in length. One end of the telescopic hinge structure is hinged to a vertical slip ring, and the other end is connected to the shaft of a torsional magnetic negative stiffness mechanism. The low-frequency vibration isolator also includes a first horizontal fixed ring, a second horizontal fixed ring, a third horizontal fixed ring, and a fourth horizontal fixed ring. The two horizontal slip rings are the first horizontal slip ring and the second horizontal slip ring, respectively. The first horizontal fixed ring and the second horizontal fixed ring are fixed to the two ends of the first horizontal slip ring, and the third horizontal fixed ring and the fourth horizontal fixed ring are fixed to the two ends of the second horizontal slip ring.

2. The hydrophone demodulation interferometer according to claim 1, characterized in that, The torsional magnetic negative stiffness mechanism further includes a housing, a first bearing, a second bearing, an inner magnet, and an outer magnet. The housing has a groove inside, and the outer magnet is tile-shaped. The outer magnet is evenly distributed along the circumference and fixed in the groove of the housing. The rotating shaft is placed inside the housing, and the two ends of the rotating shaft are connected to the two ends of the housing through the first bearing and the second bearing. The inner magnet is fixed to the surface of the rotating shaft. The outer magnet and the inner magnet are radially magnetized, and the magnetic force directions of the outer magnet and the inner magnet are consistent, forming a repulsive magnetic field.

3. The hydrophone demodulation interferometer according to claim 2, characterized in that, The two vibration isolation units are the first vibration isolation unit and the second vibration isolation unit, respectively. The first vibration isolation unit includes a first vertical guide rod, a first vertical fixing ring, a first vertical spring, and a first vertical slip ring. The first vertical guide rod is fixed to the side of the foundation platform. The first vertical fixing ring is sleeved on the bottom of the first vertical guide rod. The first vertical spring is sleeved on the first vertical guide rod and located above the first vertical fixing ring. The first vertical slip ring is sleeved on the first vertical guide rod. The second vibration isolation unit includes a second vertical guide rod, a second vertical fixing ring, a second vertical spring, and a second vertical slip ring. The second vertical guide rod is fixed to the side of the foundation platform. The second vertical fixing ring is sleeved on the bottom of the second vertical guide rod. The second vertical spring is sleeved on the second vertical guide rod and located above the second vertical fixing ring. The second vertical slip ring is sleeved on the second vertical guide rod. The first vibration isolation unit also includes a first positioning bushing, which is fixed to the upper surface of the foundation platform by bolts, and a first vertical guide rod is inserted into the first positioning bushing; The second vibration isolation unit also includes a second positioning bushing, which is fixed to the upper surface of the foundation platform by bolts, and a second vertical guide rod is inserted into the second positioning bushing.

4. The hydrophone demodulation interferometer according to claim 3, characterized in that, The first vibration isolation unit also includes a first mounting base, which is L-shaped. The base plate of the first mounting base is fixed to the foundation platform, and the side plate of the first mounting base is provided with a horizontal through hole. A horizontal guide rod passes through the through hole of the side plate of the first mounting base. The second vibration isolation unit also includes a second mounting base, which is L-shaped. The base plate of the second mounting base is fixed to the foundation platform, and the side plate of the second mounting base is provided with a horizontal through hole. A horizontal guide rod passes through the through hole of the side plate of the second mounting base.

5. The hydrophone demodulation interferometer according to claim 4, characterized in that, The two telescopic hinge structures are designated as the first telescopic hinge structure and the second telescopic hinge structure, respectively; the two torsional magnetic negative stiffness mechanisms are designated as the first torsional magnetic negative stiffness mechanism and the second torsional magnetic negative stiffness mechanism, respectively. The first telescopic hinge structure includes a first telescopic link and a second telescopic link. Both the first telescopic link and the second telescopic link are hinged at one end to the semi-circular rectangular connector of the first vertical slip ring, and at the other end to the rotating shaft of the first torsional magnetic negative stiffness mechanism. The second telescopic hinge structure includes a third telescopic link and a fourth telescopic link. Both the third and fourth telescopic links are hinged at one end to the semi-circular rectangular connector of the second vertical slip ring, and at the other end to the rotating shaft of the second torsional magnetic negative stiffness mechanism.

6. The hydrophone demodulation interferometer according to claim 5, characterized in that, The first telescopic link and the second telescopic link are respectively connected to the rotating shaft of the first torsional magnetic negative stiffness mechanism via flat keys, and the third telescopic link and the fourth telescopic link are respectively connected to the rotating shaft of the second torsional magnetic negative stiffness mechanism via flat keys.

7. The hydrophone demodulation interferometer according to claim 6, characterized in that, Both the first vertical fixing ring and the second vertical fixing ring are fixed by locking bolts.

8. The hydrophone demodulation interferometer according to claim 7, characterized in that, The first horizontal fixing ring and the second horizontal fixing ring are fixed to both ends of the first horizontal slip ring by locking bolts, and the third horizontal fixing ring and the fourth horizontal fixing ring are fixed to both ends of the second horizontal slip ring by locking bolts.

9. The hydrophone demodulation interferometer according to claim 8, characterized in that, The basic platform is a rectangular plate structure.

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