A distributed passive acoustic decoy simulator with a multi-float space structure

Abstract

This invention discloses a distributed passive acoustic decoy simulator with a multi-buoy spatial structure, comprising multiple individual models arranged linearly along the towing direction and sequentially connected by flexible connectors. Each individual model has a streamlined shape and a rigid frame structure welded from stainless steel square tubing. The rigid frame structure contains an array of floats, along with a counterweight unit to balance buoyancy. This invention utilizes multiple floats to form spatially discrete acoustic scattering units, and multiple individual models connected in series to form a distributed passive acoustic equivalent, effectively simulating the distribution characteristics and directional features of underwater vehicle target intensity. The rigid frame structure, as the main load-bearing component, combined with the design of the fairing and counterweight unit, improves the attitude stability of the simulator and the spatial positional stability of the scattering units under towing and complex hydrodynamic conditions. Furthermore, this simulator is inexpensive and easy to assemble and maintain.

Description

Technical Field

[0001] This invention belongs to the field of underwater acoustic engineering technology and relates to a distributed passive acoustic decoy simulator with a multi-buoy spatial structure. Background Technology

[0002] Acoustic decoys are divided into active and passive types. Active acoustic decoys suppress or replicate signals by emitting high-energy signals. In particular, active acoustic decoys can receive and process active acoustic detection signals before emitting them, and use multiple transponder elements to simulate the echo of underwater targets, thereby accurately reproducing target characteristics. In contrast, passive acoustic decoys do not actively emit acoustic signals. Instead, they use passive jamming elements to create false echoes, scattering active sonar signals and disrupting their detection and identification capabilities.

[0003] Passive acoustic decoys have advantages such as fast reaction speed, low exposure and high mobility, showing great potential in underwater acoustic countermeasures. Existing passive acoustic decoys have the following technical problems: (1) They mostly rely on expensive deep-sea solid buoyancy materials, which limits the feasibility of large-scale production of passive acoustic decoys; (2) They generally adopt an integral rigid structure or a single scatterer form, which has the problem of concentrated scattering center and single echo spatial distribution characteristics, making it difficult to characterize the intensity characteristics of multi-scattering center targets distributed along the axial direction of underwater vehicles; (3) In long-distance towing and complex hydrodynamic environments, although existing passive acoustic decoys can meet the basic structural strength requirements, their working attitude stability and scattering unit spatial distribution stability are insufficient, and they are easily affected by water flow disturbances, resulting in attitude deflection or relative position changes, thus affecting the consistency of echo characteristics and simulation effect. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a low-cost, distributed passive acoustic decoy simulator with a multi-buoy spatial structure that can simulate the intensity characteristics of multi-scattering center targets distributed along the axial direction of an underwater vehicle, and has high working attitude stability and high spatial distribution stability of scattering units.

[0005] Technical Solution: The present invention provides a distributed passive acoustic decoy simulator with a multi-buoy spatial structure, comprising multiple individual models arranged linearly along the towing direction. These individual models are sequentially connected by flexible connectors to form a distributed structure. Each individual model includes a rigid frame structure for bearing towing loads and hydrodynamic loads. Multiple floats arranged in an array are fixedly disposed within the rigid frame structure, forming spatially discrete acoustic scattering units. The rigid frame structure is externally provided with a head fairing, a tail fairing, an upper cover plate, a lower base plate, and two side plates, forming a streamlined shape. Drainage holes are provided on the side plates of the block to reduce internal water accumulation and additional hydrodynamic effects, so as to maintain the buoyancy and attitude stability of the single model during operation. The single model is equipped with a counterweight unit, which works with the floats to adjust the overall buoyancy distribution and longitudinal attitude of the single device, so as to maintain the stability of the relative spatial position of each acoustic scattering unit. Multiple floats form discrete scattering centers under the action of incident sound waves. The echoes of each discrete scattering center are superimposed in the far field, so that the single model forms an acoustic simulation unit with multi-scattering center characteristics. Multiple single models form a distributed passive acoustic equivalent body on the overall scale, which is used to simulate the spatial distribution characteristics and directional characteristics of the target intensity of underwater vehicles.

[0006] Furthermore, the flexible connector is made of Kevlar fiber rope.

[0007] Furthermore, the rigid frame structure is formed by welding multiple square tubes.

[0008] Furthermore, the square tube is made of stainless steel.

[0009] Furthermore, the floats are arranged in layers along the height direction and in a linear array along the horizontal direction, with the same spacing between adjacent floats, to ensure the spatial stability and acoustic consistency of each sound scattering unit.

[0010] Furthermore, the floats in the same layer are connected and fixed to the rigid frame structure by cylindrical rods.

[0011] Furthermore, the counterweight unit is made of lead blocks and is fixed to the bottom plate below.

[0012] Furthermore, the flexible connector passes through the fairing and connects to the lifting ring on the rigid frame structure.

[0013] Furthermore, the front fairing is composed of a lower base plate, a frontal plate, an upper cover plate, and two symmetrical side plates.

[0014] Furthermore, the tail fairing has a similar structure to the head fairing. At the same time, the tail fairing has a vertical wing on the upper cover plate and a horizontal wing on the outer side of the symmetrical side plate. The horizontal wings of the tail fairing are symmetrical on both sides.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0016] (1) The components such as floats and plates used in this invention are low in cost, which improves the problem of high material cost of existing passive acoustic decoys and is conducive to large-scale production and application.

[0017] (2) This invention uses multiple floats to form spatially discrete acoustic scattering units, and connects multiple individual models sequentially along the towing direction to form a distributed structure. The multiple individual models can correspond to different scattering regions of the underwater vehicle. The overall device formed by the series connection of multiple individual models constitutes a distributed passive acoustic equivalent, which can simulate different scattering regions of the target in segments, thereby improving the simulation capability of the spatial distribution characteristics and directional characteristics of the underwater vehicle target intensity. This improves the problems of concentrated scattering centers, single acoustic characteristics, and difficulty in simulating the axial multi-scattering center characteristics of underwater vehicles that exist in existing passive acoustic decoys.

[0018] (3) The present invention adopts a rigid frame structure as the main load-bearing component, and combines the design of the head fairing, tail fairing and counterweight unit to improve the attitude stability of the simulation device under towing and complex hydrodynamic conditions and the spatial position stability of the scattering unit, thereby improving the problems of unstable working attitude and easy fluctuation of simulation effect of existing passive acoustic decoys. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the distributed passive acoustic decoy simulator with multi-float space structure provided in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the single-unit model in an embodiment of the present invention;

[0021] Figure 3 These are three views of the rigid frame structure in an embodiment of the present invention, wherein (a) is the front view, (b) is the side view, and (c) is the top view;

[0022] Figure 4 This is a schematic diagram of the structure of the first flow guide fairing in an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the structure of the upper cover plate in an embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the side plate structure in an embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of the tail fairing in an embodiment of the present invention, wherein (a) is a front view and (b) is a side view;

[0026] Figure 8 This is a schematic diagram of the structure of the lower base plate in an embodiment of the present invention;

[0027] Figure 9 This is a target intensity directivity diagram of the simulated body device at 1000Hz in an embodiment of the present invention;

[0028] Figure 10 This is the target intensity directivity diagram of the simulated body device at 3000Hz in this embodiment of the invention. Detailed Implementation

[0029] The invention will now be further described with reference to the accompanying drawings.

[0030] Appendix Figures 1 to 10 The accompanying figure labels are as follows:

[0031] 1. Head fairing; 2. Rigid frame structure; 3. Upper cover plate; 4. Float; 5. Cylindrical rod; 6. Tail fairing; 7. Lead weight; 8. Lower base plate; 9. Side plates; 10. Angled fastener; 11. Long fastener; 12. M8 lifting ring; 13. Square tube short rod; 14. Square tube long rod; 15. M12 lifting ring; 16. Right-angle L-shaped fastener; 17. Angled L-shaped fastener; 18. Trailing hole; 19. Drainage hole; 20, M6 screw hole; 21, M8 screw hole; 22, lower base plate of the front fairing; 23, front fairing frontal vane; 24, symmetrical side plates of the front fairing; 25, upper cover plate of the front fairing; 26, vertical wing of the tail fairing; 27, tail plate of the tail fairing; 28, symmetrical side plates of the tail fairing; 29, upper cover plate of the tail fairing; 30, lower base plate of the tail fairing; 31, horizontal side wing of the tail fairing.

[0032] like Figure 1 As shown, this embodiment of the invention provides a distributed passive acoustic decoy simulator with a multi-buoy spatial structure, comprising three individual models arranged linearly along the towing direction. The three individual models are sequentially connected by Kevlar fiber ropes to form a distributed structure, with a total towing length of 120m in water. The three individual models can correspond to the bow, midships, and stern respectively according to the echo distribution characteristics of the underwater vehicle, thereby achieving segmented simulation of different scattering regions.

[0033] like Figure 2 and Figure 3As shown, the single-unit model includes a rigid frame structure 2 welded from stainless steel square tubing, which serves as the main load-bearing component of the single-unit model. The rigid frame structure 2 is fixedly fitted with a front fairing 1, a rear fairing 6, an upper cover plate 3, a lower base plate 8, and two side plates 9 on its outer side, thus forming a streamlined shape. Inside the rigid frame structure 2, 20 floats 4 are arranged in a 5×4 array. Four cylindrical rods 5 are welded and fixed at equal intervals from top to bottom inside the rigid frame structure 2, with five floats 4 threaded onto each cylindrical rod 5. In this embodiment, the floats 4 have a diameter of 30cm, the spacing between adjacent cylindrical rods 5 is 30cm, and the float positions are fixed at both ends of the cylindrical rods 5 using M20 nuts. The centers of all floats 4 are located on the same plane to ensure the spatial distribution consistency of the scattering units.

[0034] The connection points between the rigid frame structure 2 and the front fairing 1 and the rear fairing 6 are equipped with long square tube rods 14 and short square tube rods 13, along with oblique fasteners 10 and long fasteners 11 to meet structural fixation requirements. Furthermore, M8 lifting rings 12 for towing are installed on the long square tube rods 14 at the connection points between the rigid frame structure 2 and the front and rear fairings 1 and 6, symmetrically distributed at both ends, with four rings at each end.

[0035] An M12 lifting ring 15 is provided at the connection between the rigid frame structure 2 and the upper cover plate 3 to facilitate the taking-up, taking-down and hoisting of the individual model.

[0036] like Figure 4 As shown, the front fairing 1 is assembled from a lower base plate 22, a frontal plate 23, two symmetrical side plates 24, and an upper cover plate 25 using right-angle L-shaped fasteners 16, oblique L-shaped fasteners 17, and bolts. M6 screw holes 20 are distributed at the connection points between the lower base plate 22, the upper cover plate 25, and the two symmetrical side plates 24 and the rigid frame structure 2. The front fairing 1 is connected and fixed to the rigid frame structure 2 using oblique fasteners 10, long fasteners 11, and bolts. The frontal plate 23 has drag holes 18 for Kevlar fiber ropes to pass through, and drainage holes 19 are provided on each plate constituting the front fairing 1. The angle between the frontal plate 23 and the symmetrical side plates 24 is 110° to form a better airflow guiding shape.

[0037] like Figure 5 and Figure 6 As shown, both the upper cover plate 3 and the side plate 9 are provided with connection holes. The upper cover plate 3 has M6 screw holes 20, M8 screw holes 21, and a drainage hole 19. The M6 ​​screw holes 20 are used to bolt the upper cover plate 3 to the rigid frame structure 2, and the M8 screw holes 21 are used to fix the M12 lifting ring 15. The side plate 9 has M6 screw holes 20 and a drainage hole 19. The M6 ​​screw holes 20 are used to fix the side plate 9 to the rigid frame structure 2.

[0038] like Figure 7 As shown, the tail fairing 6 is formed by assembling the tail fairing vertical wing 26, the tail fairing tail plate 27, the tail fairing symmetrical side plate 28, the tail fairing upper cover plate 29, the tail fairing lower base plate 30, and the tail fairing horizontal side wing 31 through right-angle L-shaped fasteners 16, oblique L-shaped fasteners 17, and bolts.

[0039] M6 screw holes 20 are distributed at the connection points between the tail fairing upper cover plate 29, the tail fairing lower base plate 30, and the two symmetrical tail fairing side plates 28 and the rigid frame structure 2. The tail fairing 6 is connected and fixed to the rigid frame structure 2 by oblique fasteners 10, long fasteners 11, and bolts. The tail fairing tail plate 27 has a drag hole 18 for Kevlar fiber ropes to pass through, and drainage holes 19 are provided on each plate constituting the tail fairing 6. The tail fairing horizontal wings 31 are arranged on the outer side of the symmetrical tail fairing side plates 28, and the two tail fairing horizontal wings 31 are symmetrical. The tail fairing vertical wing 26 is set at the center of the tail fairing upper cover plate 29 to improve the flow state at the tail of the single model and enhance the attitude stability during dragging.

[0040] Lead blocks 7 are installed on the bottom plate 8 to work with the floats 4 to adjust the buoyancy distribution and longitudinal attitude of the single-unit model. Specifically... Figure 8 As shown, lead blocks 7 are fixed to the lower base plate 8 via M8 screw holes 21 and bolts, and are symmetrically distributed along the lower base plate 8. The lower base plate 8 also has drainage holes 19 and M6 screw holes 20, where the M6 ​​screw holes 20 are used to connect the lower base plate 8 to the rigid frame structure 2. The lead blocks 7 and the floats 4 work together to adjust the buoyancy and stability of the single-unit model in water.

[0041] In this embodiment, the front fairing 1, the rear fairing 6, the upper cover plate 3, and the two side plates 9 are all made of fiberglass plates. The rigid frame structure 2 is welded from 304 stainless steel square tubes, and the lower base plate 8 is made of steel plate to meet the load-bearing requirements.

[0042] Figure 9 and Figure 10 The target intensity directivity results of the simulator at 1000Hz and 3000Hz are shown respectively, where 90° corresponds to the transverse direction. As can be seen from the figure, the target intensity radiation pattern of the simulator exhibits obvious directional characteristics, indicating that the simulator can form an overall scattering response with certain distribution characteristics through the spatial distribution of multiple floats and the series structure of multiple individual models, thereby simulating the spatial distribution characteristics of underwater vehicle target intensity.

Claims

1. A distributed passive acoustic decoy simulator with a multi-floating sphere spatial structure, characterized in that, The system includes multiple individual models arranged linearly along the towing direction, which are sequentially connected by flexible connectors to form a distributed structure. Each individual model includes a rigid frame structure (2) for bearing towing loads and hydrodynamic loads. Multiple floats (4) are fixedly arranged in an array inside the rigid frame structure (2), and the floats (4) constitute spatially discrete acoustic scattering units. The rigid frame structure (2) is provided with a head fairing (1), a tail fairing (6), an upper cover plate (3), a lower bottom plate (8), and two side plates (9) on its outer side, forming a streamlined shape. Drainage holes (19) are provided on the side plate (9) to reduce internal water accumulation and additional hydrodynamic effects, so as to maintain the floating state and attitude stability of the single model when it is working. The single model is equipped with a counterweight unit, which is used to coordinate with the float (4) to adjust the overall buoyancy distribution and longitudinal attitude of the single device, so as to maintain the stability of the relative spatial position of each acoustic scattering unit. Multiple floats (4) form discrete scattering centers under the action of incident sound waves. The echoes of each discrete scattering center are superimposed in the far field, so that the single model forms an acoustic simulation unit with multiple scattering center characteristics. Multiple single models form a distributed passive acoustic equivalent body on the overall scale, which is used to simulate the spatial distribution characteristics and directional characteristics of the target intensity of underwater vehicles.

2. The distributed passive acoustic decoy simulator with multi-buoy space structure according to claim 1, characterized in that, The flexible connector is made of Kevlar fiber rope.

3. The distributed passive acoustic decoy simulator with multi-buoy space structure according to claim 1, characterized in that, The rigid frame structure (2) is formed by welding multiple square tubes.

4. The distributed passive acoustic decoy simulator with multi-buoy space structure according to claim 3, characterized in that, The square tube is made of stainless steel.

5. The distributed passive acoustic decoy simulator with multi-buoy space structure according to claim 1, characterized in that, The floats (4) are arranged in layers along the height direction and in a linear array along the horizontal direction. The adjacent floats (4) have the same spacing to ensure the spatial stability and acoustic consistency of each sound scattering unit.

6. The distributed passive acoustic decoy simulator with multi-buoy space structure according to claim 5, characterized in that, The floats (4) in the same layer are connected and fixed to the rigid frame structure (2) by cylindrical rods (5).

7. The distributed passive acoustic decoy simulator with multi-buoy space structure according to claim 1, characterized in that, The counterweight unit uses lead blocks (7) and is fixed on the bottom plate (8).

8. The distributed passive acoustic decoy simulator with multi-buoy space structure according to claim 1, characterized in that, The flexible connector passes through the shroud and is connected to the lifting ring on the rigid frame structure (2).

9. The distributed passive acoustic decoy simulator with multi-buoy space structure according to claim 1, characterized in that, The front fairing (1) is composed of the lower base plate (22) of the front fairing, the front fairing front plate (23), the upper cover plate (25) of the front fairing and two symmetrical side plates (24) of the front fairing.

10. The distributed passive acoustic decoy simulator with multi-buoy space structure according to claim 9, characterized in that, The tail fairing (6) is similar in structure to the head fairing (1). At the same time, the tail fairing upper cover plate (29) is provided with a tail fairing vertical wing (26), and the tail fairing horizontal wing (31) is provided on the outside of the tail fairing symmetrical side plate (28). The two tail fairing horizontal wings (31) are symmetrical.

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