Underwater depth-fixing suspension device based on acoustic target intensity enhancement of folded inflatable corner reflector

Abstract

An underwater fixed-depth suspension device based on folding inflatable corner reflector for enhancing the acoustic target intensity is composed of an inflatable corner reflector and functional cabins such as a storage cabin, an inflatable cabin, an electronic cabin, a depth sensor, a counterweight cabin, a power cabin, and a propeller, and is in the shape of multiple cylindrical cabin sections. The strong echo generated by the corner reflector structure can be used to enhance the acoustic target intensity, and the folding inflatable structure and its supporting functional cabin can be used to achieve underwater storage and maintain a fixed-depth hovering state in the water after launch. When detected by active sonar, a strong echo is formed, which can be used for underwater acoustic jammer design, and can also be used as a target echo bright spot simulation for underwater passive acoustic decoy design. The present invention has the characteristics of multi-directional geometric scattering enhancement, and has the ability to hover at a fixed depth in the water, which is easy to fold, store and deploy. The attached device has good mid- and high-frequency acoustic stealth performance, the device cost and working energy consumption are low, and it can be deployed lightly and energy-savingly, which is suitable for short-term use scenarios such as jammers and target simulation acoustic decoys.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater vehicle hydroacoustic technology, and in particular relates to an underwater depth-fixing suspension device based on folded inflatable corner reflector acoustic target intensity enhancement. Background Art

[0002] Corner reflectors can be used as jammers and target simulations due to their scattering enhancement effect, and have strong military value. Existing corner reflector technology is widely used in the radar field. It floats on the water surface in an inflated state or is installed on ships with a rigid reflective surface with a hard structure to achieve the effect of enhancing the radar scattering cross section (RCS). In the field of hydroacoustics, a variety of corner reflector structures with enhanced acoustic target intensity have also been proposed, such as a steel reflective surface corner reflector structure with an inner inflated layer, and a combined structure of a corner reflector bracket with a flexible reflective surface. However, it is difficult to deploy and hover the steel reflective surface corner reflector structure underwater, and a flexible corner reflector that can be folded and stored is preferred. At present, the hydroacoustic field is mainly based on the design of the corner reflector structure itself, and there is no corner reflector device that can fully realize the underwater fixed depth hovering application.

[0003] Patent document CN117075089A discloses "a high-pressure water-filled branch-expandable underwater acoustic combined corner reflector structure", which adopts water-filled expansion to form a combined corner reflector structure with a foldable or windable belt. However, the ability of the high-pressure water-filled support structure of the structure to maintain the shape of the corner reflector is unknown. The various reflecting surfaces of the corner reflector are still air-filled or hollow glass microbead sandwich flexible sound-reflecting cloth, which needs to be inflated in advance or attached with underwater supporting devices. Moreover, the structure is only a part of the corner reflector structure, and its ability to maintain a floating state in water is unknown. Summary of the invention

[0004] In order to overcome the shortcomings and gaps in the above-mentioned prior art, the present invention provides an underwater fixed depth suspension device based on folding inflatable corner reflector acoustic target intensity enhancement, which uses the strong echo generated by the corner reflector structure to achieve target intensity enhancement, and uses the folding inflatable structure and its supporting functional cabin to achieve underwater storage and maintain the fixed depth suspension state in the water after launch. When detected by active sonar, a strong echo is formed, which can be used for underwater acoustic jammer design, and can also be used as a target echo bright spot simulation for underwater passive acoustic bait design. The device can be used to achieve underwater acoustic target intensity enhancement, and has the characteristics of convenient and flexible use, low cost, and stable and durable.

[0005] The technical solution of the present invention is as follows:

[0006] An underwater acoustic target intensity enhancement device can be carried and deployed by a surface ship or an underwater vehicle, and is characterized in that the device comprises two parts: a corner reflector structure and a functional cabin;

[0007] The device is cylindrical before use. When in use, it is dropped into the water and sinks or floats to a specified depth. Then the folded corner reflector is released and inflated, so that the inflated corner reflector and the connected main cabin section are in a suspended state. With the help of an adaptive propulsion device, it becomes a passive sound scatterer that hovers at a fixed depth in the water. When the inflated corner reflector in the water is irradiated by active sonar sound waves, its sound target intensity has an enhanced effect, and it can act as an acoustic jammer or a target acoustic simulation body.

[0008] The corner reflector structure has two states: folding and storage and inflating and unfolding. When the device sinks or floats after being launched, the corner reflector is in the folding and storage state. When the corner reflector is inflated and suspended to become a sound interferer or a simulation body, the corner reflector is in the inflating and unfolding state.

[0009] The corner reflector is mainly composed of an umbrella-shaped bracket and a flexible corner reflecting surface.

[0010] The umbrella-shaped bracket provides strength to resist hydrostatic pressure to maintain the shape of the inflatable corner reflector, and is folded and unfolded using the basic working principle of an umbrella to facilitate storage and placement. When the corner reflector is in a folded and stored state, the umbrella-shaped bracket is also in a vertically folded state and installed in a storage cabin. When the corner reflector is released from the functional cabin, the umbrella-shaped bracket unfolds and is fixed in an umbrella shape, while supporting the flexible corner reflective surface to unfold, and is inflated with the help of an inflatable tube to form the shape of the corner reflector. The corner reflector and the functional cabin are connected by a Kevlar rope and an inflatable tube, so that the inflatable corner reflector has pressure resistance and maintains its external shape.

[0011] The functional cabin is composed of a storage cabin, an inflatable cabin, an electronic cabin, a depth sensor, a counterweight cabin, a power cabin, a propeller, etc., and is in the shape of multiple cylindrical cabin sections.

[0012] The main functions of the functional cabin include: (1) providing storage space for the corner reflector and inflating it; (2) providing weight support to maintain the zero-gravity state of the entire device; (3) providing power adjustment capability to maintain a dynamic fixed-depth suspension state; (4) an acoustic covering layer is laid on the outer surface of the structure and has good sound absorption performance, so that its influence on the corner reflector echo is minimized; (5) the overall structure meets the deep-sea pressure resistance and interface watertightness requirements.

[0013] The storage cabin is located at the top of the functional cabin, and is composed of a corner reflector umbrella-shaped bracket, a flexible corner reflective surface, an inflation tube, a watertight cover and a Kevlar rope. The corner reflector umbrella-shaped bracket and the flexible corner reflective surface are installed in the storage cabin in a folded storage state, and the watertight cover at the top port is controlled by the electronic cabin. After opening, water enters the storage cabin, and the corner reflector folding bracket and the flexible bag float out of the storage cabin. Then the high-pressure gas cylinder of the inflation cabin is inflated and expanded through the inflation tube.

[0014] After being deployed, the corner reflector maintains a certain distance from the functional cabin to reduce the influence of the sound scattering of the functional cabin on the sound scattering of the corner reflector. The corner reflector is connected to the functional cabin through an inflation tube and a Kevlar rope. The inflation tube provides inflation for it, and the Kevlar rope provides tension protection for it.

[0015] The inflatable chamber includes a high-pressure gas cylinder. The gas volume of the high-pressure gas cylinder should be determined based on the inflation volume of the corner reflector and the hydrostatic pressure at a specified depth to prevent the compressed volume of the air in the corner reflector from becoming smaller under static pressure and failing to meet the inflation requirements of the corner reflector. The high-pressure gas cylinder should have good deep-sea hydrostatic watertightness.

[0016] The electronic cabin mainly includes a depth sensing processor, a cover opening controller, and an inflation controller, which are used to receive the depth sensor data for processing and control the opening and closing of the storage cabin cover, control the thruster to adaptively adjust the floating depth when the entire device is in a dynamic suspension state, and control the high-pressure gas cylinder to inflate the corner reflector and its bracket after the top is released. The power supply provides power to the electronic cabin, the external interface of the electronic cabin is hydrostatically watertight, and the components inside the cabin are fixed to prevent shaking and damage.

[0017] The depth sensor is located below the electronic cabin and immersed in water, records the water pressure at all times, and obtains water depth data. The water depth data is not only the triggering basis for fixed-depth inflation, but also the monitoring basis for dynamic suspension.

[0018] The depth sensor transmits the sensed depth data to the electronic cabin. When the functional cabin reaches or exceeds the specified depth, the electronic cabin issues a command to trigger the switch to open the watertight cover of the storage cabin port to deploy the corner reflector. The water depth is monitored in real time during the entire operation process, and the propulsion device is controlled to maintain a dynamic fixed-depth suspension state.

[0019] The counterweight cabin provides gravity for the entire device. The internal counterweight can be configured in advance according to the buoyancy and is detachably installed. The counterweight can be flexibly adjusted according to the displacement volume of the inflatable corner reflector equipped. The counterweight makes the center of gravity of the functional cabin at the bottom. After the corner reflector is released and inflated, the buoyancy center of the entire device is much higher than the center of gravity. The higher center of gravity enables it to quickly form a vertical state.

[0020] The power cabin includes batteries, motors, transmission mechanisms, and shaft systems. The batteries directly provide power to the electronic cabin, and also provide power to the propellers through the motors, transmission mechanisms, and shaft systems. The electronic cabin controls the power output. It is advisable to use batteries with small size, high density, and large energy storage, and calculate the energy storage according to the inflation deployment process and hovering time.

[0021] The thruster is a propeller with vertical forward and reverse propulsion function. When the functional cabin is higher than the specified depth, the thruster provides upward thrust, and vice versa, it provides downward thrust, so that the entire device maintains a dynamic equilibrium state near the specified depth. The thrust size is adaptively controlled by the electronic cabin according to the depth deviation. Since the entire device has a high center of gravity and has the ability to self-recover in the vertical state, no lateral thrust control is required.

[0022] The outer surface of the functional cabin is covered with a sound-absorbing covering layer and has good sound-absorbing performance, so that the influence of the layer on the echo of the corner reflector is reduced as much as possible.

[0023] The application method of the device is:

[0024] 1) According to the target intensity simulation requirements, design the size parameters of the inflatable corner reflector and calculate its total drainage volume.

[0025] 2) Set the corner reflector deployment depth and calculate the corresponding hydrostatic pressure.

[0026] 3) The mass of the gas under the internal and external balanced forces after the gas is subjected to hydrostatic pressure is calculated based on the volume of the inflated corner reflector, and the sum of the mass of the gas in the inflation tube is the gas reserve provided by the high-pressure gas cylinder.

[0027] 4) Calculate the buoyancy of the device in the stowed state without the volume of the inflatable corner reflector by the method of displacement volume. The total buoyancy of the device in the entire inflated deployed state is obtained based on the buoyancy of the volume of the inflatable corner reflector and the buoyancy of the device in the stowed state. Then, the required counterweight is obtained by calculating the difference between the gross weight of the entire device without the counterweight, so that it meets the zero buoyancy condition, so as to maintain the dynamic suspension state by the up and down micro-thrust of the thruster.

[0028] 5) The device is launched into the water through the carrier platform. The depth sensor starts working after entering the water and senses the water depth in real time, and transmits the depth data to the electronic cabin for processing and control. If the water depth of the device is less than the specified depth, the electronic cabin triggers the top storage hatch cover opening command when it sinks to the specified depth. If the water depth of the device is not less than the specified depth, the top storage hatch cover opening command is immediately triggered.

[0029] 6) After the cover is opened, water enters the storage cabin, and the corner reflector floats out from the opening on the top of the storage cabin. The electronic cabin commands the compressed gas cylinder to inflate the corner reflector. The flexible bag of the corner reflector is unfolded synchronously with the folding bracket. After forming, the bracket is fixed with buckles to support the external shape of the corner reflector. The inflated corner reflector and the main device are in a vertical state.

[0030] 7) After the corner reflector is inflated and deployed, if the water depth of the device is greater than the specified depth, the thruster provides an upward thrust, otherwise the thruster provides a downward thrust, so that the device attenuates oscillation near the zero buoyancy state position, and the propulsion energy consumption is minimized when the device stops at the specified depth through gradual depth adaptive control.

[0031] 8) When the inflatable corner reflector and the device are illuminated by active sonar, the inflatable corner reflector generates a strong echo due to its tetrahedral structure, while the surface of the main device is coated with medium and high frequency strong sound absorbing materials and the echo is weak, which has little effect on the strong echo of the corner reflector, thereby achieving the effect of enhancing the intensity of the acoustic target.

[0032] The present invention has the following advantages:

[0033] (1) A flexible octahedral reflector structure is used as a corner reflector, which has a multi-directional geometric scattering enhancement effect;

[0034] (2) The corner reflector contains a foldable carbon fiber bracket, which can be folded for easy storage and deployment, and can also provide strength to resist hydrostatic pressure to maintain the external shape of the corner reflector;

[0035] (3) With the help of a depth sensor, a propulsion device and a controller to form an adaptive propulsion system, the corner reflector becomes a passive sound scatterer that can hover at a fixed depth in the water and has the ability to adapt to deep water environments;

[0036] (4) The main device is covered with a sound-absorbing covering layer on the outside, which has good mid- and high-frequency acoustic stealth performance and is suitable for common aircraft detection working frequency bands;

[0037] (5) The inflatable device has a low cost and is suitable for short-term use scenarios such as jammers and target simulation acoustic decoys;

[0038] (6) The right-angled surface of each corner reflector is an air layer, which does not need to be very thick under the support of the skeleton, and can fully save the inflation volume, thereby reducing the counterweight and achieving lightweight and energy-saving deployment.

[0039] 7) Compared with CN117075089, the present invention utilizes a steel structure as a support to improve the shape-maintaining ability of the corner emitter under deep water and high pressure, utilizes an umbrella-shaped support to realize the storage and underwater deployment of the corner reflector, utilizes an adaptive propulsion device to realize the underwater constant-depth suspension ability, utilizes the gravity of the supporting equipment to realize the overall zero buoyancy state to reduce energy consumption, and provides support for the design of passive acoustic bait. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of an underwater depth-fixing suspension device based on foldable inflatable corner reflector acoustic target intensity enhancement provided by an embodiment of the present invention, (a) stowed state, (b) inflated and suspended state;

[0041] Figure 2 An inflatable structure diagram of an underwater umbrella-shaped support provided by an embodiment of the present invention, (a) the support is in the unfolding state, and (b) the support is in the unfolded state;

[0042] Figure 3The acoustic cover layer acoustic stealth function cabin provided in the embodiment of the present invention;

[0043] Figure 4 This is a diagram showing the effect of enhancing the acoustic target intensity of a corner reflector provided in an embodiment of the present invention, (a) corner reflector, (b) solid sphere;

[0044] Numbers in the figure: 1. Corner reflector structure; 2. Functional cabin; 3. Umbrella-shaped bracket; 4. Flexible corner reflective surface; 5. Slip ring; 6. Buckle; 7. Inflatable tube; 8. Kevlar rope; 9. Storage cabin; 10. Inflatable cabin; 11. Electronic cabin; 12. Depth sensor; 13. Counterweight cabin; 14. Power cabin; 15. Thruster; 16. Watertight cover; 17. Carbon fiber high-pressure gas cylinder; 18. Battery; 19. Connecting rod; 20. Wire mesh; 21. Counterweight; 22. Electric motor; 23. Transmission mechanism; 24. Shaft system; 25. Control module; 26. Sound-absorbing covering layer; 27. Spring; 28. Air hole. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] See also Figure 1 The present invention is an underwater depth-fixing suspension device based on a folded inflatable corner reflector for enhancing the acoustic target intensity. The device is an underwater acoustic target intensity enhancement device that can be carried and deployed by a surface ship or an underwater vehicle, and consists of two parts: a corner reflector structure 1 and a functional cabin 2.

[0047] The device is cylindrical before use. When in use, it is dropped into the water and sinks or floats to a specified depth. The corner reflector is then released and inflated, so that the corner reflector and the connected main cabin section are in a suspended state after inflation. With the help of an adaptive propulsion device, it becomes a passive sound scatterer that hovers at a fixed depth in the water. When the inflated corner reflector in the water is irradiated by active sonar sound waves, its acoustic target intensity is enhanced, and it can serve as an acoustic jammer or a target acoustic simulation body.

[0048] The corner reflector structure has two states: folding and storage and inflating and unfolding. When the device sinks or floats after being launched, the corner reflector is in the folding and storage state. When the corner reflector is inflated and suspended to become a sound interferer or a simulation body, the corner reflector is in the inflating and unfolding state.

[0049] The corner reflector is mainly composed of an umbrella-shaped support 3 and a flexible corner reflective surface 4.

[0050] The umbrella-shaped bracket 3 provides strength to resist hydrostatic pressure to maintain the shape of the inflatable corner reflector, and is folded and unfolded using the basic working principle of an umbrella for easy storage and placement. When the corner reflector is in a folded storage state, the umbrella-shaped bracket is also in a vertically folded state and is installed in the storage cabin 9. When the corner reflector is released from the functional cabin, the umbrella-shaped bracket is unfolded in an umbrella shape through the spring 27 and the push slip ring 5. When the slip ring 5 slides to the buckle 6, the umbrella-shaped bracket is tightened and fixed, and at the same time supports the flexible corner reflective surface 4 to unfold. After being inflated through the air hole 28 with the help of the inflation tube 7, the corner reflector is formed. The corner reflector and the functional cabin are connected by the Kevlar rope 8 and the inflation tube 7, so that the inflatable corner reflector has pressure resistance and maintains its external shape.

[0051] The functional cabin 2 is composed of a storage cabin 9, an inflatable cabin 10, an electronic cabin 11, a depth sensor 12, a counterweight cabin 13, a power cabin 14, a thruster 15, etc., and is in the shape of multiple cylindrical cabin sections.

[0052] The main functions of the functional cabin 2 include: (1) providing storage space for the corner reflector and inflating it; (2) providing weight support to maintain the zero gravity state of the entire device; (3) providing power adjustment capability to maintain a dynamic fixed-depth suspension state; (4) an acoustic covering layer is laid on the outer surface of the structure and has good sound absorption performance, so that its influence on the corner reflector echo is minimized; (5) the overall structure meets the deep-sea pressure resistance and interface watertightness requirements.

[0053] The storage cabin 9 is located at the top of the functional cabin 2, and is composed of a corner reflector umbrella-shaped bracket 3, a flexible corner reflective surface 4, an inflation tube 7, a watertight cover 16 and a Kevlar rope 8. The corner reflector umbrella-shaped bracket 3 and the flexible corner reflective surface 4 are installed in the storage cabin 9 in a folded storage state, and the top port watertight cover 16 is controlled by the electronic cabin 11. After opening, water enters the storage cabin 9, and the corner reflector folding bracket 3 and the flexible corner reflective surface 4 float out of the storage cabin 9, and then the carbon fiber high-pressure gas cylinder 17 of the inflation cabin 10 is inflated and expanded through the inflation tube 7.

[0054] After the corner reflector structure 1 is unfolded, it maintains a certain distance from the functional cabin 2 to reduce the influence of the sound scattering of the functional cabin 2 on the sound scattering of the corner reflector. The corner reflector is connected to the functional cabin 2 through an inflation tube 7 and a Kevlar rope 8. The inflation tube 7 provides inflation for it, and the Kevlar rope 8 provides tension protection for it.

[0055] The inflatable chamber 10 includes a high-pressure gas cylinder 17. The inflation volume of the high-pressure gas cylinder 17 should be determined based on the inflation volume of the corner reflector and the hydrostatic pressure at a specified depth to prevent the compressed volume of the air in the corner reflector from becoming smaller under static pressure and failing to meet the inflation requirements of the corner reflector. The high-pressure gas cylinder 17 should have good deep-sea hydrostatic watertightness.

[0056] The electronic cabin 11 mainly includes a control module 25 such as a depth sensing processor, a cover opening controller, and an inflation controller, and a battery 18. Its function is to receive the depth sensor data for processing and control the opening and closing of the watertight cover plate 16 at the top port of the storage cabin, control the propeller 15 to adaptively adjust the floating depth when the entire device is in a dynamic suspension state, and control the high-pressure gas cylinder 17 to inflate the corner reflector and its bracket after the top is released. The battery 18 provides power for the electronic cabin 11, and the external interface of the electronic cabin 11 is subjected to static pressure watertight treatment, and the components in the cabin are fixed to prevent shaking and damage.

[0057] The depth sensor 12 is located below the electronic cabin 11 and immersed in water, and records the water pressure at all times and obtains water depth data. The water depth data is not only a triggering basis for fixed depth inflation, but also a monitoring basis for dynamic suspension.

[0058] The depth sensor 12 transmits the sensed depth data to the electronic cabin 11. When the functional cabin 2 reaches or exceeds the specified depth, the electronic cabin 11 issues a command to trigger the switch to open the watertight cover 16 of the storage cabin port to deploy the corner reflector 1. During the entire operation process, the water depth is monitored in real time, and the propulsion device is controlled to maintain a dynamic fixed-depth suspension state. The depth sensor 12 is protected by a connecting rod 19 and a wire mesh 20.

[0059] The counterweight cabin 13 provides gravity for the entire device. The internal counterweight 21 can be configured in advance according to the buoyancy and is detachably installed. The counterweight can be flexibly adjusted according to the displacement volume of the inflatable corner reflector equipped. The counterweight 21 makes the center of gravity of the functional cabin 2 at the bottom. After the corner reflector is released and inflated, the buoyancy center of the entire device is much higher than the center of gravity. The higher center of gravity enables it to quickly form a vertical state.

[0060] The power cabin 14 includes a battery 18, an electric motor 22, a transmission mechanism 23, and a shaft system 24. The battery 18 directly provides power to the electronic cabin 11, and also provides power to the propeller through the electric motor 22, the transmission mechanism 23 and the shaft system 24. The power output is controlled by the electronic cabin. It is advisable to use a small-volume, high-density, and high-energy-storage battery, and calculate the energy storage according to the inflation deployment process and the hovering time.

[0061] The thruster 15 is a propeller with the function of forward and reverse propulsion in the vertical direction. When the functional cabin is higher than the specified depth, the thruster provides upward thrust, and vice versa, it provides downward thrust, so that the entire device maintains a dynamic equilibrium state near the specified depth. The thrust size is adaptively controlled by the electronic cabin according to the depth deviation. Since the entire device has a high metacentricity and has the ability to self-recover in the vertical state, no lateral thrust control is required.

[0062] The outer surface of the functional cabin 2 is provided with a sound-absorbing covering layer 26 and has good sound-absorbing performance, so that the influence of the sound-absorbing covering layer 26 on the corner reflector echo is reduced as much as possible.

[0063] The application method of the underwater depth-fixing suspension device based on the folded inflatable corner reflector for enhancing the acoustic target intensity comprises the following steps:

[0064] The application method of the device is:

[0065] 1) According to the target intensity simulation requirements, design the size parameters of the inflatable corner reflector and calculate its total drainage volume.

[0066] 2) Set the corner reflector deployment depth and calculate the corresponding hydrostatic pressure.

[0067] 3) The mass of gas under the internal and external balanced forces after being subjected to hydrostatic pressure is calculated based on the volume of the inflated corner reflector. The sum of the mass of gas in the inflation tube is the net gas reserve provided by the high-pressure gas cylinder, with a certain margin left.

[0068] 4) Calculate the buoyancy of the device in the stowed state without the volume of the inflatable corner reflector by the method of displacement volume. The total buoyancy of the device in the entire inflated deployed state is obtained based on the buoyancy of the volume of the inflatable corner reflector and the buoyancy of the device in the stowed state. Then, the required counterweight is obtained by calculating the difference between the gross weight of the entire device without the counterweight, so that it meets the zero buoyancy condition, so as to maintain the dynamic suspension state by the up and down micro-thrust of the thruster.

[0069] 5) After the device is configured and before use, complete the functional and safety inspection, mainly including checking the watertightness and airtightness, checking the bearing capacity of the structure and materials after the corner reflector is inflated, the propulsion power, verifying the actual gravity buoyancy of the device, and inspecting the intensity of the corner reflector's acoustic target and the sound absorption performance of the acoustic covering shell.

[0070] 6) The device is launched into the water through the carrier platform. The depth sensor starts working after entering the water and senses the water depth in real time, and transmits the depth data to the electronic cabin for processing and control. If the water depth of the device is less than the specified depth, the electronic cabin triggers the top storage hatch cover opening command when it sinks to the specified depth. If the water depth of the device is not less than the specified depth, the top storage hatch cover opening command is immediately triggered.

[0071] 7) After the cover is opened, water enters the storage cabin, and the corner reflector floats out from the opening on the top of the storage cabin. The electronic cabin commands the compressed gas cylinder to inflate the corner reflector. The flexible bag of the corner reflector is unfolded synchronously with the folding bracket. After forming, the bracket is fixed with a buckle to support the external shape of the corner reflector. The inflated corner reflector and the main device are in a vertical state.

[0072] 8) After the corner reflector is inflated and deployed, if the water depth of the device is greater than the specified depth, the thruster provides an upward thrust, otherwise the thruster provides a downward thrust, so that the device attenuates oscillation near the zero buoyancy state position, and the propulsion energy consumption is minimized when the device stops at the specified depth through gradual depth adaptive control.

[0073] 9) When the inflatable corner reflector and the device are illuminated by active sonar, the inflatable corner reflector generates a strong echo due to its tetrahedral structure, while the surface of the main device is coated with medium and high frequency strong sound absorbing materials and the echo is weak, which has little effect on the strong echo of the corner reflector, thereby achieving the effect of enhancing the intensity of the acoustic target.

[0074] Experiments show that the underwater depth-fixing suspension device based on folding inflatable corner reflector with enhanced acoustic target intensity has the following advantages: (1) A flexible octahedral corner reflector structure is used as a corner reflector, which has a multi-directional geometric scattering enhancement effect; (2) The corner reflector contains a folding carbon fiber bracket, which can be folded for easy storage and deployment, and can also provide strength to resist hydrostatic pressure to maintain the external shape of the corner reflector; (3) With the help of a depth sensor, a propulsion device and a controller to form an adaptive propulsion system, the corner reflector becomes a passive acoustic scatterer for depth-fixing hovering in the water, and has the ability to adapt to deep water environments; (4) A sound-absorbing covering layer is laid on the outside of the main device, which has good mid- and high-frequency acoustic stealth performance and is suitable for common aircraft detection working frequency bands; (5) The inflatable device has a low cost and is suitable for short-term use scenarios such as jammers and target simulation acoustic baits; (6) The right-angle surface of each corner reflector is an air layer, which does not need to be very thick under the support of the skeleton, and can fully save the inflation volume, thereby reducing the counterweight and achieving lightweight and energy-saving deployment.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An underwater acoustic target intensity enhancement hovering device, characterized in that: It includes two parts: corner reflector structure and functional cabin; The corner reflector structure is composed of an umbrella-shaped bracket and a plurality of flexible corner reflective surfaces covering the umbrella-shaped bracket. The umbrella-shaped bracket can be folded and unfolded, and becomes an umbrella shape after being inflated and unfolded, and forms a strong echo sound scatterer with the flexible corner reflective surfaces; The functional cabin is in the shape of a multi-section cylinder, which is divided into a storage cabin, an inflatable cabin, an electronic cabin, a power cabin and a propeller from top to bottom, wherein the storage cabin accommodates the corner reflector structure, and a Kevlar rope and an inflation tube for connecting the corner reflector structure and the functional cabin; the electronic cabin accommodates a depth sensing processor, a cover opening controller and an inflation controller, which obtains and receives processing data through the depth sensor, controls the switch of the watertight cover plate at the top port of the storage cabin, controls the propeller to adaptively adjust the suspension depth when the entire device is in a dynamic suspension state, and controls the high-pressure gas cylinder in the inflatable cabin to inflate it after the corner reflector and its bracket are released from the top; the power cabin is used to provide power for the propeller, realizes forward and reverse propulsion in the vertical direction through the control of the electronic cabin, and maintains the dynamic balance of the device at a specified depth.

2. The underwater acoustic target intensity enhancement hovering device according to claim 1, characterized in that: The functional cabin is also provided with a counterweight cabin, which provides a detachable counterweight, which can be flexibly adjusted according to the displacement volume of the inflatable corner reflector equipped to maintain the stability of the device in the water and to maintain the zero gravity state of the entire device.

3. The underwater acoustic target intensity enhancement hovering device according to claim 1, characterized in that: A sound-absorbing covering layer is laid on the outer surface of the functional cabin to reduce the influence of sound scattering of the corner reflector.

4. The underwater acoustic target intensity enhancement hovering device according to claim 1, characterized in that: The storage cabin is located at the top of the functional cabin and is used to store and release the corner reflector and its bracket in a folded state. The watertight cover of the top port is controlled by the electronic cabin and can release the corner reflector and inflate it after opening.

5. The underwater acoustic target intensity enhancement hovering device according to claim 1, characterized in that: The depth sensor records the water pressure in real time and transmits it to the electronic cabin as a monitoring basis for fixed-depth inflation and dynamic suspension.

6. The underwater acoustic target intensity enhancement hovering device according to claim 4, characterized in that: After launching into the water, the umbrella-shaped support and the inflation tube in the storage cabin rush out of the storage cabin, and the carbon fiber high-pressure gas cylinder (17) of the inflation cabin (10) is inflated and expanded through the inflation tube (7).

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