A coaxial segmented underwater acoustic towed array based on MEMS
By employing a coaxial segmented design and an aramid fiber bundle support layer in the underwater acoustic towed array, the problems of bulkiness and fragility of traditional towed array structures have been solved, achieving lightweight design and signal protection, and improving the detection capability and reliability of unmanned platforms.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- OCEAN UNIV OF CHINA
- Filing Date
- 2026-05-20
- Publication Date
- 2026-07-21
AI Technical Summary
Traditional underwater acoustic towed linear arrays have large outer diameters, resulting in high hydrodynamic drag and easy tensile fracture, making them unsuitable for the needs of micro unmanned platforms.
The coaxial segmented underwater acoustic towed linear array based on MEMS is adopted. By setting sensing nodes at intervals on the tensile load-bearing linear body, using aramid fiber bundles as the central load-bearing layer, and combining the design of carrier, shielding cover and fluid acoustic medium, lightweight structure and signal protection are achieved.
The outer diameter of the towed linear array is controlled within 15 mm, reducing navigation resistance, increasing detection range, improving system maintainability and flexibility, preventing internal wear and mechanical fatigue, and ensuring that MEMS chips can work normally in the deep sea environment.
Smart Images
Figure CN122237658B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of underwater acoustic detection equipment technology, specifically to a MEMS-based coaxial segmented underwater acoustic towed linear array. Background Technology
[0002] In recent years, with the widespread adoption of new unmanned and miniaturized marine exploration platforms such as unmanned underwater vehicles and autonomous underwater vehicles, traditional underwater acoustic towed structures are facing platform compatibility issues. For example, existing towed linear arrays typically have an outer diameter of over 30mm, resulting in a bulky structure. When towed in water, these thick cables generate significant hydrodynamic drag, severely depleting the limited power of the miniature unmanned platform and drastically shortening its range. Furthermore, the large-scale wake vortices generated by the thick cables easily reveal the platform's location. Therefore, developing flexible towed linear arrays with smaller outer diameters has become a key focus in the field of underwater acoustic engineering.
[0003] The most common type of thin-diameter towed line array currently is constructed by arranging multi-core signal wires and sensor nodes in parallel or twisted configurations inside the cable body. The outer layer is woven from aramid fiber or high-strength steel wire into a load-bearing mesh, and finally, the cable body is solidly encapsulated with polyurethane or epoxy resin. However, this type of thin-diameter towed line array suffers from problems such as easy tensile breakage, high flow noise, and easy internal wear during use. Summary of the Invention
[0004] To address the aforementioned technical issues, this invention proposes a MEMS-based coaxial segmented underwater acoustic towed linear array.
[0005] The technical solution adopted in this invention is: A MEMS-based coaxial segmented underwater acoustic towed linear array includes a tensile-bearing wire body, and sensing nodes are spaced apart on the tensile-bearing wire body. The sensing nodes include a carrier and a circuit board arranged on the carrier. The carrier includes a back plate, a U-shaped plate, and a shielding cover, with one end of the U-shaped plate connected to the back plate; A preamplifier circuit is arranged on the front side of the circuit board, and a MEMS acoustic sensor chip is bonded to the back side of the circuit board. The MEMS acoustic sensor chip is connected to the preamplifier circuit, and the MEMS acoustic sensor chip and the preamplifier circuit are arranged in a staggered manner on the circuit board. The circuit board is inserted into the U-shaped plate and is located at the bottom of the groove of the U-shaped plate, with the front of the circuit board facing upwards. The shielding cover is set above the groove of the U-shaped plate. The circuit board extends outwards relative to the U-shaped plate, and a notch is provided at the outwardly extending end of the circuit board. The MEMS acoustic sensing chip is arranged at the notch. The circuit boards of each sensing node are connected by cables; The back plate is provided with a first through hole for the tensile load-bearing wire to pass through, and a second through hole for the cable to pass through; A watertight protective sleeve is installed on the outside of the tensile bearing line, and an annular fluid cavity is formed between the watertight protective sleeve and the tensile bearing line. The annular fluid cavity is filled with a fluid sound-permeable medium.
[0006] The beneficial technical effects of the present invention are as follows: (1) This invention changes the traditional structure of external braided armor for load-bearing cables, arranging non-metallic aramid fiber bundles at the center (mechanical neutral axis) of the cable's geometric cross-section, i.e., the underwater acoustic towed array. This coaxial layout concentrates the macroscopic axial tension of the entire array at the center, thereby minimizing the stress on the peripheral MEMS chips, micro-wires, and circuit boards, achieving a balance between high load-bearing capacity and ultra-fine radial space. The structure of this invention is extremely fine, with the array outer diameter controlled within 15 mm, significantly reducing navigation resistance and deployment / retraction volume, enabling small unmanned underwater vehicles to carry longer arrays and improve detection range.
[0007] (2) The carrier structure designed in this invention uses a shield to protect the preamplifier circuit while supporting the circuit board. The metal shield is grounded as a whole, sealing the internal signal wires and amplifier circuit in its internal space. This shield can effectively isolate external interference, including electromagnetic radiation in the underwater environment and interference signals from other devices, preventing them from intruding into the preamplifier circuit and causing signal distortion and increased noise. In addition, the long and complex cable is divided into multiple relatively independent sections by the partition plate, so that each section can be tested and assembled independently, and when a section is damaged, it will not affect the other sections, improving the maintainability of the system and the flexibility of array length configuration.
[0008] (3) The present invention is provided with a telescopic buckle and an annular bearing clamp in the first through hole. The telescopic buckle can automatically compensate for the diameter fluctuation when the fiber bundle is stretched / relaxed; the annular bearing clamp can play a role in precise centering, locking the fiber bundle at the geometric center of the cable body and preventing radial movement. Combined with the carrier structure design, the present invention effectively solves the reliability problems of internal wear, abrasive contamination, and shielding layer damage in existing ultra-fine towing arrays, and has good bending flexibility.
[0009] (4) This invention adopts an encapsulation structure composed of an ultra-thin TPU protective sleeve and vacuum-filled silicone oil. Utilizing the fluid incompressible properties of silicone oil, the external deep-sea hydrostatic pressure is directly converted into an internal isotropic isostatic load, making the pressure difference between the inside and outside of the protective sleeve tend to be balanced. Combined with the through-hole design of the circuit board at the corresponding MEMS chip, it ensures that the pressure can be quickly and evenly distributed, protecting the internal structure from unidirectional mechanical compression. At the same time, the carrier in this invention has small lateral slippage along the central tensile bearing line, and the internal coaxial fluid cavity provides radial slippage buffer for the rigid electronic components, enabling the array to perform small displacement release and deformation compensation when bending at large curvatures, effectively avoiding mechanical fatigue fracture caused by stress concentration. Attached Figure Description
[0010] Figure 1 This is a schematic diagram illustrating the structural principle of the MEMS-based coaxial segmented underwater acoustic towed linear array of the present invention. Figure 2 This is a schematic diagram of the structure after the circuit board at the sensing node is connected to the carrier in this invention; Figure 3 for Figure 2 Another viewpoint; Figure 4 for Figure 2 The third-angle view; Figure 5 This is a schematic diagram of the carrier structure without the shielding cover in this invention.
[0011] In the diagram: 1-tensile load-bearing line, 2-carrier, 3-circuit board, 4-cable, 5-watertight protective sleeve, 6-fluid sound-permeable medium, 7-telescopic buckle, 8-ring bearing clamp, 9-fixing pin; 201-Backplate, 202-U-shaped plate, 203-Shielding cover, 204-Separator plate; 2011 - First through hole, 2012 - Second through hole; 301 - MEMS acoustic sensor chip, 302 - notch. Detailed Implementation
[0012] Addressing the urgent need for lightweight acoustic towed structures and low hydrodynamic drag in underwater micro-unmanned platforms, existing towed arrays, when reduced to an outer diameter of 15 mm or less, are highly susceptible to tensile fracture, bending fatigue fracture, deep-water compression damage, and internal frictional wear due to complex ocean towed flow fields. Therefore, this invention proposes a MEMS-based coaxial segmented underwater acoustic towed array. Through the coordinated design of the coaxial segmented structure, oil filling, and carrier structure, it solves the technical challenges of tensile fracture, bending fatigue, deep-water high-pressure damage, and internal wear of ultra-fine cables under complex operating conditions, while meeting the requirement of extremely fine wire diameter.
[0013] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0014] like Figure 1 As shown, a coaxial segmented underwater acoustic towed linear array based on MEMS includes a tensile load-bearing linear body 1, and sensing nodes are arranged at intervals on the tensile load-bearing linear body 1. The sensing nodes include a carrier 2 and a circuit board 3 arranged on the carrier 2. Figure 1 Only a portion of the underwater acoustic towed line array is shown. For example... Figures 2-5As shown, the carrier 2 includes a back plate 201, a U-shaped plate 202, and a shielding cover 203. One end of the U-shaped plate 202 is connected to the back plate 201. A preamplifier circuit is arranged on the front of the circuit board 3 (not shown in the figure). A MEMS acoustic sensor chip 301 is bonded to the back of the circuit board 3. The MEMS acoustic sensor chip 301 is connected to the preamplifier circuit, and the MEMS acoustic sensor chip and the preamplifier circuit are staggered on the circuit board, corresponding to each other at both ends. The circuit board 3 is placed in the groove of the U-shaped plate, with its front side facing upwards. A shielding cover 203 is also provided above the groove of the U-shaped plate. A notch 302 is provided at the outward-extending end of the circuit board 3, directly opposite the MEMS acoustic sensor chip; that is, the MEMS acoustic sensor chip 301 is located at the notch 302. The circuit boards 3 of each sensing node are connected by cables 4. The back plate 201 has a first through hole 2011 for the tensile load-bearing wire 1 to pass through, and a second through hole 2012 for the cable to pass through. A watertight protective sleeve 5 is provided on the outside of the tensile load-bearing wire 1, and an annular fluid cavity is formed between the watertight protective sleeve 5 and the tensile load-bearing wire 1. The annular fluid cavity is filled with a fluid sound-permeable medium 6.
[0015] The aforementioned carrier 2 also includes a partition plate 204, which is circular and connected to the back plate 201. The partition plate and the U-shaped plate are respectively disposed on both sides of the back plate. The first through hole 2011 and the second through hole 2012 are both arranged through the partition plate 204 and the back plate 201. The underwater acoustic towed array is segmented by the partition plate 204, and independent segmented regions are formed between the partition plates of two adjacent sensing nodes.
[0016] The aforementioned tensile-bearing wire 1 serves as the central layer or tensile-bearing layer of the underwater acoustic towed array. It is made of aramid fiber bundles, and the aramid fiber bundles are located at the center of the cross-section of the underwater acoustic towed array, that is, the tensile-bearing wire 1 is at the center of the entire array cross-section. The diameter of the tensile-bearing wire 1 is 0.6-0.8 mm, and a high-strength and tough central Kevlar aramid fiber bundle with a diameter of 0.6 mm can be specifically used.
[0017] When the linear array is subjected to high-speed drag of hundreds of Newtons in water, the macroscopic axial tensile force on the system is forcibly concentrated and transmitted to this central layer, which bears the force independently, because the aramid fiber bundle is located at the absolute geometric center of the cable cross-section. Electronic components and wires arranged around the center of the aramid fiber bundle do not physically participate in the axial load-bearing, thus blocking the physical path of mechanical tensile force transmission to vulnerable cores such as the watertight protective sleeve, solving the problem of hard breakage. Simultaneously, the non-metallic material avoids generating alternating electromagnetic interference to external signals as a central load-bearing component.
[0018] The watertight protective sleeve is made of polyurethane material and has a thickness of 0.8-1.2 mm. The diameter of the underwater acoustic towed array of the present invention is less than 15 mm.
[0019] like Figure 5 As shown, the first through hole 2011 is located below the second through hole 2012, and the first through hole 2011 and the second through hole 2012 are located on the lower and upper sides of the plane where the circuit board 3 is located, respectively. The tensile load-bearing wire 1 passes through the first through hole 2011 of the carrier at each sensing node, and the first through hole is circular. The second through hole 2012 is rectangular or elliptical, and the cable 4 connecting the circuit board passes through the second through hole 2012.
[0020] This invention features a series of axially equidistant sensing nodes arranged around the exterior of the tensile-bearing conductor 1. Each node includes a circuit board, such as a PCB, with a MEMS acoustic sensing chip bonded to the reverse side and an ultra-low noise preamplifier circuit arranged on the front. The circuit boards of each sensing node are electrically connected via multi-core fluoroplastic insulated micro-cables, which are laid parallel or slightly twisted along the axial direction outside the tensile-bearing layer. Signal interfaces are arranged on both sides of the front of the circuit board for convenient power grounding and signal line routing.
[0021] This invention integrates a high-sensitivity MEMS chip with a preamplifier circuit board over an extremely short distance, enabling the weak acoustic analog signal to be amplified instantly upon conversion to an electrical signal. This significantly increases the voltage amplitude of the source signal, reduces line loss and sensitivity to distributed capacitance during long-distance transmission over thin cables, and weakens the physical conditions for crosstalk at the signal source. Furthermore, this invention integrates the circuit board onto a carrier, which is equipped with a shielding cover 203, achieving both electromagnetic shielding and resolving the issues of friction, wear, and fixation between the central aramid bundle and the shielding layer.
[0022] As a further design of the present invention, a telescopic buckle 7 is provided at one end of the first through hole 2011 to adapt to changes in the diameter of the tensile load-bearing cable. The inner diameter of the telescopic buckle 7 elastically expands and contracts within the range of 0.2-0.5 mm. When the aramid bundle is stretched, causing its diameter to decrease, the telescopic buckle automatically contracts to maintain light contact; when the aramid bundle relaxes and its diameter recovers, the buckle elastically opens without generating additional resistance. An annular bearing clamp 8 is also provided at the other end of the first through hole 2011 to radially limit the tensile load-bearing cable. The annular bearing clamp 8 precisely positions the aramid bundle at the geometric center of the cable body, preventing radial movement. The telescopic buckle 7 and the annular bearing clamp 8 can be implemented using existing conventional structures.
[0023] The backplate 201 and U-shaped plate 202 are an integral structure made of aluminum alloy. A fixing pin 9 is provided within the groove of the U-shaped plate 202 to mate with vias on the circuit board. After the circuit board is placed in the groove of the U-shaped plate 202, the fixing pin 9 is inserted into the via on the circuit board, achieving a stable fixation. The shielding cover 203 is a metal shielding shell. The fluid sound-permeable medium is silicone oil.
[0024] This invention creates a closed-loop liquid-solid coupling system consisting of a sealed TPU watertight protective sleeve, internal silicone oil, tensile-bearing wires, and the carrier and circuit boards on top of them. This system provides resistance to pressure and bending. Specifically, because silicone oil is an incompressible fluid, when the ultra-thin TPU outer sheath is subjected to enormous unidirectional hydrostatic pressure at depths of hundreds of meters in the deep sea, the flexible sheath undergoes microscopic deformation and transmits this pressure to the internal silicone oil. Based on Pascal's principle, the silicone oil converts the external pressure into isotropic pressure within the internal microenvironment, acting uniformly on the surface of the internal components. This achieves a dynamic balance between internal and external pressures, preventing macroscopic structural collapse of the outer sheath and protecting the internal MEMS chip from rigid compression and breakage. When the linear array is subjected to large-curvature bending due to waves or eddy-induced vibrations, a relative displacement difference arises between the internal components and the outer sheath due to the different force radii. At this time, the liquid silicone oil within the cavity provides radial fluid sliding space, allowing the internal rigid circuit boards and thin cables to slide and release slightly within the cavity, compensating for radial deformation displacement. This structure effectively eliminates localized stress concentration caused by repeated bending, solving the problem of dynamic mechanical fatigue fracture in cable assemblies. Simultaneously, the fluid viscosity of the silicone oil dissipates the high-frequency mechanical vibration energy on the sheath surface caused by external turbulence, thus playing a role in mechanical filtering and noise reduction.
[0025] In summary, the coaxial segmented underwater acoustic towed linear array based on MEMS of the present invention has the following advantages: (1) Extremely fine structure: The outer diameter of the linear array is controlled within 15 mm, which greatly reduces the navigation resistance and the volume of deployment and retrieval, enabling small unmanned underwater vehicles (AUVs) to carry longer arrays and improve the detection range.
[0026] (2) Tensile strength: All dragging force is concentrated on the central Kevlar aramid tensile fiber bundle, so that the outer wires and MEMS chips bear minimal tension, solving the reliability problem that ultra-fine cables are easily torn apart when dragged at high speed.
[0027] (3) Internal friction resistance: Through the cooperation of the carrier, the circuit board and the aramid fiber bundle, combined with the structural design of telescopic buckle and ring bearing clamp, the sliding wear between the central aramid bundle and the carrier is completely eliminated, there is no wear debris pollution, the shielding cover on the circuit board and the carrier is intact and undamaged, and the service life of the whole cable is greatly extended.
[0028] (4) Pressure resistance: Isostatic pressure balance is achieved by internally injecting silicone oil, and the incompressible property of liquid is used to offset the external high water pressure. Combined with the notch design on the carrier corresponding to the MEMS chip, the delicate MEMS chip is protected from being crushed and can still work normally in the deep sea environment.
[0029] Of course, the above description is only a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiments. It should be noted that any equivalent substitutions or obvious modifications made by those skilled in the art under the guidance of this specification fall within the scope of this specification and should be protected by the present invention.
Claims
1. A MEMS-based coaxial segmented underwater acoustic towed linear array, characterized in that: It includes a tensile bearing line, and sensing nodes are arranged at intervals on the tensile bearing line. The sensing nodes include a carrier and a circuit board arranged on the carrier. The carrier includes a back plate, a U-shaped plate, and a shielding cover, with one end of the U-shaped plate connected to the back plate; A preamplifier circuit is arranged on the front side of the circuit board, and a MEMS acoustic sensor chip is bonded to the back side of the circuit board. The MEMS acoustic sensor chip is connected to the preamplifier circuit, and the MEMS acoustic sensor chip and the preamplifier circuit are arranged in a staggered manner on the circuit board. The circuit board is inserted into the U-shaped plate and is located at the bottom of the groove of the U-shaped plate, with the front of the circuit board facing upwards. The shielding cover is set above the groove of the U-shaped plate. The circuit board extends outwards relative to the U-shaped plate, and a notch is provided at the outwardly extending end of the circuit board. The MEMS acoustic sensing chip is arranged at the notch. The circuit boards of each sensing node are connected by cables; The back plate is provided with a first through hole for the tensile load-bearing wire to pass through, and a second through hole for the cable to pass through; A watertight protective sleeve is installed on the outside of the tensile bearing line, and an annular fluid cavity is formed between the watertight protective sleeve and the tensile bearing line. The annular fluid cavity is filled with a fluid sound-permeable medium. The tensile load-bearing line is made of aramid fiber bundles, and the aramid fiber bundles are located at the center of the cross section of the underwater acoustic towing line array. The diameter of the tensile load-bearing wire is 0.6-0.8 mm; the watertight protective sleeve is made of polyurethane material and has a thickness of 0.8-1.2 mm; the diameter of the underwater acoustic towed array is less than 15 mm. The carrier also includes a partition plate, which is circular and connected to the back plate via a connector. The partition plate and the U-shaped plate are respectively disposed on both sides of the back plate. The first through hole and the second through hole are both arranged through the partition plate and the back plate. The underwater acoustic drag array is segmented by the partition plate, and an independent segmented area is formed between the partition plates of two adjacent sensing nodes. A telescopic buckle is provided at one end of the first through hole to accommodate changes in the diameter of the tensile bearing line. The inner diameter of the telescopic buckle can elastically expand and contract within the range of 0.2-0.5 mm.
2. The MEMS-based coaxial segmented underwater acoustic towed linear array according to claim 1, characterized in that: The first through hole is located below the second through hole, and the first through hole and the second through hole are located on opposite sides of the plane of the circuit board; the first through hole is circular, and the second through hole is elliptical.
3. The MEMS-based coaxial segmented underwater acoustic towed linear array according to claim 1, characterized in that: At the other end of the first through hole, there is also a ring bearing clamp for radial limiting of the tensile bearing line.
4. The MEMS-based coaxial segmented underwater acoustic towed linear array according to claim 1, characterized in that: The back plate and the U-shaped plate are an integral structure. A fixing pin is also provided in the groove of the U-shaped plate to match the vias on the circuit board. The shielding cover is made of metal housing.
5. A MEMS-based coaxial segmented underwater acoustic towed linear array according to claim 1, characterized in that: The fluid sound-transmitting medium is silicone oil.